diff options
Diffstat (limited to 'libpng/contrib/libtests')
| -rw-r--r-- | libpng/contrib/libtests/fakepng.c | 57 | ||||
| -rwxr-xr-x | libpng/contrib/libtests/gentests.sh | 102 | ||||
| -rw-r--r-- | libpng/contrib/libtests/makepng.c | 1486 | ||||
| -rw-r--r-- | libpng/contrib/libtests/pngimage.c | 1652 | ||||
| -rw-r--r-- | libpng/contrib/libtests/pngstest.c | 3818 | ||||
| -rw-r--r-- | libpng/contrib/libtests/pngunknown.c | 1245 | ||||
| -rw-r--r-- | libpng/contrib/libtests/pngvalid.c | 11238 | ||||
| -rw-r--r-- | libpng/contrib/libtests/readpng.c | 104 | ||||
| -rw-r--r-- | libpng/contrib/libtests/tarith.c | 999 | ||||
| -rw-r--r-- | libpng/contrib/libtests/timepng.c | 303 |
10 files changed, 21004 insertions, 0 deletions
diff --git a/libpng/contrib/libtests/fakepng.c b/libpng/contrib/libtests/fakepng.c new file mode 100644 index 000000000..fcc111286 --- /dev/null +++ b/libpng/contrib/libtests/fakepng.c @@ -0,0 +1,57 @@ +/* Fake a PNG - just write it out directly. */ +#include <stdio.h> +#include <zlib.h> /* for crc32 */ + +void +put_uLong(uLong val) +{ + putchar(val >> 24); + putchar(val >> 16); + putchar(val >> 8); + putchar(val >> 0); +} + +void +put_chunk(const unsigned char *chunk, uInt length) +{ + uLong crc; + + put_uLong(length-4); /* Exclude the tag */ + + fwrite(chunk, length, 1, stdout); + + crc = crc32(0, Z_NULL, 0); + put_uLong(crc32(crc, chunk, length)); +} + +const unsigned char signature[] = +{ + 137, 80, 78, 71, 13, 10, 26, 10 +}; + +const unsigned char IHDR[] = +{ + 73, 72, 68, 82, /* IHDR */ + 0, 0, 0, 1, /* width */ + 0, 0, 0, 1, /* height */ + 1, /* bit depth */ + 0, /* color type: greyscale */ + 0, /* compression method */ + 0, /* filter method */ + 0 /* interlace method: none */ +}; + +const unsigned char unknown[] = +{ + 'u', 'n', 'K', 'n' /* "unKn" - private safe to copy */ +}; + +int +main(void) +{ + fwrite(signature, sizeof signature, 1, stdout); + put_chunk(IHDR, sizeof IHDR); + + for (;;) + put_chunk(unknown, sizeof unknown); +} diff --git a/libpng/contrib/libtests/gentests.sh b/libpng/contrib/libtests/gentests.sh new file mode 100755 index 000000000..f0f8d2395 --- /dev/null +++ b/libpng/contrib/libtests/gentests.sh @@ -0,0 +1,102 @@ +#!/bin/sh +# +# Copyright (c) 2013 John Cunningham Bowler +# +# Last changed in libpng 1.6.0 [February 14, 2013] +# +# This code is released under the libpng license. +# For conditions of distribution and use, see the disclaimer +# and license in png.h +# +# Generate a set of PNG test images. The images are generated in a +# sub-directory called 'tests' by default, however a command line argument will +# change that name. The generation requires a built version of makepng in the +# current directory. +# +usage(){ + exec >&2 + echo "$0 [<directory>]" + echo ' Generate a set of PNG test files in "directory" ("tests" by default)' + exit 1 +} + +mp="$PWD/makepng" +test -x "$mp" || { + exec >&2 + echo "$0: the 'makepng' program must exist" + echo " in the directory within which this program:" + echo " $mp" + echo " is executed" + usage +} + +# Just one argument: the directory +testdir="tests" +test $# -gt 1 && { + testdir="$1" + shift +} +test $# -eq 0 || usage + +# Take care not to clobber something +if test -e "$testdir" +then + test -d "$testdir" || usage +else + # mkdir -p isn't portable, so do the following + mkdir "$testdir" 2>/dev/null || mkdir -p "$testdir" || usage +fi + +# This fails in a very satisfactory way if it's not accessible +cd "$testdir" +:>"test$$.png" || { + exec >&2 + echo "$testdir: directory not writable" + usage +} +rm "test$$.png" || { + exec >&2 + echo "$testdir: you have create but not write privileges here." + echo " This is unexpected. You have a spurion; "'"'"test$$.png"'"'"." + echo " You need to remove this yourself. Try a different directory." + exit 1 +} + +# Now call makepng ($mp) to create every file we can think of with a +# reasonable name +doit(){ + for gamma in "" --sRGB --linear --1.8 + do + case "$gamma" in + "") + gname=;; + --sRGB) + gname="-srgb";; + --linear) + gname="-lin";; + --1.8) + gname="-18";; + *) + gname="-$gamma";; + esac + "$mp" $gamma "$1" "$2" "test-$1-$2$gname.png" + done +} +# +for ct in gray palette +do + for bd in 1 2 4 8 + do + doit "$ct" "$bd" + done +done +# +doit "gray" "16" +# +for ct in gray-alpha rgb rgb-alpha +do + for bd in 8 16 + do + doit "$ct" "$bd" + done +done diff --git a/libpng/contrib/libtests/makepng.c b/libpng/contrib/libtests/makepng.c new file mode 100644 index 000000000..9f11b2964 --- /dev/null +++ b/libpng/contrib/libtests/makepng.c @@ -0,0 +1,1486 @@ +/* makepng.c + * + * Copyright (c) 2013 John Cunningham Bowler + * + * Last changed in libpng 1.6.1 [March 28, 2013] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Make a test PNG image. The arguments are as follows: + * + * makepng [--sRGB|--linear|--1.8] [--color=<color>] color-type bit-depth \ + * [file-name] + * + * The color-type may be numeric (and must match the numbers used by the PNG + * specification) or one of the format names listed below. The bit-depth is the + * component bit depth, or the pixel bit-depth for a color-mapped image. + * + * Without any options no color-space information is written, with the options + * an sRGB or the appropriate gAMA chunk is written. "1.8" refers to the + * display system used on older Apple computers to correct for high ambient + * light levels in the viewing environment; it applies a transform of + * approximately value^(1/1.45) to the color values and so a gAMA chunk of 65909 + * is written (1.45/2.2). + * + * The image data is generated internally. Unless --color is given the images + * used are as follows: + * + * 1 channel: a square image with a diamond, the least luminous colors are on + * the edge of the image, the most luminous in the center. + * + * 2 channels: the color channel increases in luminosity from top to bottom, the + * alpha channel increases in opacity from left to right. + * + * 3 channels: linear combinations of, from the top-left corner clockwise, + * black, green, white, red. + * + * 4 channels: linear combinations of, from the top-left corner clockwise, + * transparent, red, green, blue. + * + * For color-mapped images a four channel color-map is used and the PNG file has + * a tRNS chunk, as follows: + * + * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white + * 2-bit: entry 0: transparent-green + * entry 1: 40%-red + * entry 2: 80%-blue + * entry 3: opaque-white + * 4-bit: the 16 combinations of the 2-bit case + * 8-bit: the 256 combinations of the 4-bit case + * + * The palette always has 2^bit-depth entries and the tRNS chunk one fewer. The + * image is the 1-channel diamond, but using palette index, not luminosity. + * + * Image size is determined by the final pixel depth in bits, i.e. channels x + * bit-depth, as follows: + * + * 8 bits or less: 64x64 + * 16 bits: 256x256 + * More than 16 bits: 1024x1024 + * + * Row filtering is turned off (the 'none' filter is used on every row) and the + * images are not interlaced. + * + * If --color is given then the whole image has that color, color-mapped images + * will have exactly one palette entry and all image files with be 16x16 in + * size. The color value is 1 to 4 decimal numbers as appropriate for the color + * type. + * + * If file-name is given then the PNG is written to that file, else it is + * written to stdout. Notice that stdout is not supported on systems where, by + * default, it assumes text output; this program makes no attempt to change the + * text mode of stdout! + */ +#define _ISOC99_SOURCE /* for strtoull */ + +#include <stddef.h> /* for offsetof */ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <ctype.h> +#include <math.h> +#include <errno.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +/* This structure is used for inserting extra chunks (the --insert argument, not + * documented above.) + */ +typedef struct chunk_insert +{ + struct chunk_insert *next; + void (*insert)(png_structp, png_infop, int, png_charpp); + int nparams; + png_charp parameters[1]; +} chunk_insert; + +static int +channels_of_type(int color_type) +{ + if (color_type & PNG_COLOR_MASK_PALETTE) + return 1; + + else + { + int channels = 1; + + if (color_type & PNG_COLOR_MASK_COLOR) + channels = 3; + + if (color_type & PNG_COLOR_MASK_ALPHA) + return channels + 1; + + else + return channels; + } +} + +static int +pixel_depth_of_type(int color_type, int bit_depth) +{ + return channels_of_type(color_type) * bit_depth; +} + +static unsigned int +image_size_of_type(int color_type, int bit_depth, unsigned int *colors) +{ + if (*colors) + return 16; + + else + { + int pixel_depth = pixel_depth_of_type(color_type, bit_depth); + + if (pixel_depth < 8) + return 64; + + else if (pixel_depth > 16) + return 1024; + + else + return 256; + } +} + +static void +set_color(png_colorp color, png_bytep trans, unsigned int red, + unsigned int green, unsigned int blue, unsigned int alpha, + png_const_bytep gamma_table) +{ + color->red = gamma_table[red]; + color->green = gamma_table[green]; + color->blue = gamma_table[blue]; + *trans = (png_byte)alpha; +} + +static int +generate_palette(png_colorp palette, png_bytep trans, int bit_depth, + png_const_bytep gamma_table, unsigned int *colors) +{ + /* + * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white + * 2-bit: entry 0: transparent-green + * entry 1: 40%-red + * entry 2: 80%-blue + * entry 3: opaque-white + * 4-bit: the 16 combinations of the 2-bit case + * 8-bit: the 256 combinations of the 4-bit case + */ + switch (colors[0]) + { + default: + fprintf(stderr, "makepng: --colors=...: invalid count %u\n", + colors[0]); + exit(1); + + case 1: + set_color(palette+0, trans+0, colors[1], colors[1], colors[1], 255, + gamma_table); + return 1; + + case 2: + set_color(palette+0, trans+0, colors[1], colors[1], colors[1], + colors[2], gamma_table); + return 1; + + case 3: + set_color(palette+0, trans+0, colors[1], colors[2], colors[3], 255, + gamma_table); + return 1; + + case 4: + set_color(palette+0, trans+0, colors[1], colors[2], colors[3], + colors[4], gamma_table); + return 1; + + case 0: + if (bit_depth == 1) + { + set_color(palette+0, trans+0, 255, 0, 0, 0, gamma_table); + set_color(palette+1, trans+1, 255, 255, 255, 255, gamma_table); + return 2; + } + + else + { + unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */ + unsigned int x, y, ip; + + for (x=0; x<size; ++x) for (y=0; y<size; ++y) + { + ip = x + (size * y); + + /* size is at most 16, so the scaled value below fits in 16 bits + */ +# define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2)) +# define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\ + (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\ + (size*size)) + + set_color(palette+ip, trans+ip, + /* color: green, red,blue,white */ + xyinterp(x, y, 0, 255, 0, 255), + xyinterp(x, y, 255, 0, 0, 255), + xyinterp(x, y, 0, 0, 255, 255), + /* alpha: 0, 102, 204, 255) */ + xyinterp(x, y, 0, 102, 204, 255), + gamma_table); + } + + return ip+1; + } + } +} + +static void +set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth, + png_uint_32 value, png_const_bytep gamma_table, double conv) +{ + unsigned int mask = (1U << bit_depth)-1; + + x *= bit_depth; /* Maximum x is 4*1024, maximum bit_depth is 16 */ + + if (value <= mask) + { + png_uint_32 offset = x >> 3; + + if (offset < rowbytes && (bit_depth < 16 || offset+1 < rowbytes)) + { + row += offset; + + switch (bit_depth) + { + case 1: + case 2: + case 4: + /* Don't gamma correct - values get smashed */ + { + unsigned int shift = (8 - bit_depth) - (x & 0x7U); + + mask <<= shift; + value = (value << shift) & mask; + *row = (png_byte)((*row & ~mask) | value); + } + return; + + default: + fprintf(stderr, "makepng: bad bit depth (internal error)\n"); + exit(1); + + case 16: + value = (unsigned int)floor(65535*pow(value/65535.,conv)+.5); + *row++ = (png_byte)(value >> 8); + *row = (png_byte)value; + return; + + case 8: + *row = gamma_table[value]; + return; + } + } + + else + { + fprintf(stderr, "makepng: row buffer overflow (internal error)\n"); + exit(1); + } + } + + else + { + fprintf(stderr, "makepng: component overflow (internal error)\n"); + exit(1); + } +} + +static void +generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type, + int bit_depth, png_const_bytep gamma_table, double conv, + unsigned int *colors) +{ + png_uint_32 size_max = image_size_of_type(color_type, bit_depth, colors)-1; + png_uint_32 depth_max = (1U << bit_depth)-1; /* up to 65536 */ + + if (colors[0] == 0) switch (channels_of_type(color_type)) + { + /* 1 channel: a square image with a diamond, the least luminous colors are on + * the edge of the image, the most luminous in the center. + */ + case 1: + { + png_uint_32 x; + png_uint_32 base = 2*size_max - abs(2*y-size_max); + + for (x=0; x<=size_max; ++x) + { + png_uint_32 luma = base - abs(2*x-size_max); + + /* 'luma' is now in the range 0..2*size_max, we need + * 0..depth_max + */ + luma = (luma*depth_max + size_max) / (2*size_max); + set_value(row, rowbytes, x, bit_depth, luma, gamma_table, conv); + } + } + break; + + /* 2 channels: the color channel increases in luminosity from top to bottom, + * the alpha channel increases in opacity from left to right. + */ + case 2: + { + png_uint_32 alpha = (depth_max * y * 2 + size_max) / (2 * size_max); + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 2*x, bit_depth, + (depth_max * x * 2 + size_max) / (2 * size_max), gamma_table, + conv); + set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, + conv); + } + } + break; + + /* 3 channels: linear combinations of, from the top-left corner clockwise, + * black, green, white, red. + */ + case 3: + { + /* x0: the black->red scale (the value of the red component) at the + * start of the row (blue and green are 0). + * x1: the green->white scale (the value of the red and blue + * components at the end of the row; green is depth_max). + */ + png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); + png_uint_32 x; + + /* Interpolate x/depth_max from start to end: + * + * start end difference + * red: Y Y 0 + * green: 0 depth_max depth_max + * blue: 0 Y Y + */ + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 3*x+0, bit_depth, /* red */ Y, + gamma_table, conv); + set_value(row, rowbytes, 3*x+1, bit_depth, /* green */ + (depth_max * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 3*x+2, bit_depth, /* blue */ + (Y * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + } + } + break; + + /* 4 channels: linear combinations of, from the top-left corner clockwise, + * transparent, red, green, blue. + */ + case 4: + { + /* x0: the transparent->blue scale (the value of the blue and alpha + * components) at the start of the row (red and green are 0). + * x1: the red->green scale (the value of the red and green + * components at the end of the row; blue is 0 and alpha is + * depth_max). + */ + png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); + png_uint_32 x; + + /* Interpolate x/depth_max from start to end: + * + * start end difference + * red: 0 depth_max-Y depth_max-Y + * green: 0 Y Y + * blue: Y 0 -Y + * alpha: Y depth_max depth_max-Y + */ + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 4*x+0, bit_depth, /* red */ + ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 4*x+1, bit_depth, /* green */ + (Y * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 4*x+2, bit_depth, /* blue */ + Y - (Y * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + set_value(row, rowbytes, 4*x+3, bit_depth, /* alpha */ + Y + ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), + gamma_table, conv); + } + } + break; + + default: + fprintf(stderr, "makepng: internal bad channel count\n"); + exit(2); + } + + else if (color_type & PNG_COLOR_MASK_PALETTE) + { + /* Palette with fixed color: the image rows are all 0 and the image width + * is 16. + */ + memset(row, 0, rowbytes); + } + + else if (colors[0] == channels_of_type(color_type)) + switch (channels_of_type(color_type)) + { + case 1: + { + const png_uint_32 luma = colors[1]; + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + set_value(row, rowbytes, x, bit_depth, luma, gamma_table, + conv); + } + break; + + case 2: + { + const png_uint_32 luma = colors[1]; + const png_uint_32 alpha = colors[2]; + png_uint_32 x; + + for (x=0; x<size_max; ++x) + { + set_value(row, rowbytes, 2*x, bit_depth, luma, gamma_table, + conv); + set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, + conv); + } + } + break; + + case 3: + { + const png_uint_32 red = colors[1]; + const png_uint_32 green = colors[2]; + const png_uint_32 blue = colors[3]; + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 3*x+0, bit_depth, red, gamma_table, + conv); + set_value(row, rowbytes, 3*x+1, bit_depth, green, gamma_table, + conv); + set_value(row, rowbytes, 3*x+2, bit_depth, blue, gamma_table, + conv); + } + } + break; + + case 4: + { + const png_uint_32 red = colors[1]; + const png_uint_32 green = colors[2]; + const png_uint_32 blue = colors[3]; + const png_uint_32 alpha = colors[4]; + png_uint_32 x; + + for (x=0; x<=size_max; ++x) + { + set_value(row, rowbytes, 4*x+0, bit_depth, red, gamma_table, + conv); + set_value(row, rowbytes, 4*x+1, bit_depth, green, gamma_table, + conv); + set_value(row, rowbytes, 4*x+2, bit_depth, blue, gamma_table, + conv); + set_value(row, rowbytes, 4*x+3, bit_depth, alpha, gamma_table, + conv); + } + } + break; + + default: + fprintf(stderr, "makepng: internal bad channel count\n"); + exit(2); + } + + else + { + fprintf(stderr, + "makepng: --color: count(%u) does not match channels(%u)\n", + colors[0], channels_of_type(color_type)); + exit(1); + } +} + + +static void PNGCBAPI +makepng_warning(png_structp png_ptr, png_const_charp message) +{ + const char **ep = png_get_error_ptr(png_ptr); + const char *name; + + if (ep != NULL && *ep != NULL) + name = *ep; + + else + name = "makepng"; + + fprintf(stderr, "%s: warning: %s\n", name, message); +} + +static void PNGCBAPI +makepng_error(png_structp png_ptr, png_const_charp message) +{ + makepng_warning(png_ptr, message); + png_longjmp(png_ptr, 1); +} + +static int /* 0 on success, else an error code */ +write_png(const char **name, FILE *fp, int color_type, int bit_depth, + volatile png_fixed_point gamma, chunk_insert * volatile insert, + unsigned int filters, unsigned int *colors) +{ + png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, + name, makepng_error, makepng_warning); + volatile png_infop info_ptr = NULL; + volatile png_bytep row = NULL; + + if (png_ptr == NULL) + { + fprintf(stderr, "makepng: OOM allocating write structure\n"); + return 1; + } + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_structp nv_ptr = png_ptr; + png_infop nv_info = info_ptr; + + png_ptr = NULL; + info_ptr = NULL; + png_destroy_write_struct(&nv_ptr, &nv_info); + if (row != NULL) free(row); + return 1; + } + + /* Allow benign errors so that we can write PNGs with errors */ + png_set_benign_errors(png_ptr, 1/*allowed*/); + png_init_io(png_ptr, fp); + + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + png_error(png_ptr, "OOM allocating info structure"); + + { + unsigned int size = image_size_of_type(color_type, bit_depth, colors); + png_fixed_point real_gamma = 45455; /* For sRGB */ + png_byte gamma_table[256]; + double conv; + + /* This function uses the libpng values used on read to carry extra + * information about the gamma: + */ + if (gamma == PNG_GAMMA_MAC_18) + gamma = 65909; + + else if (gamma > 0 && gamma < 1000) + gamma = PNG_FP_1; + + if (gamma > 0) + real_gamma = gamma; + + { + unsigned int i; + + if (real_gamma == 45455) for (i=0; i<256; ++i) + { + gamma_table[i] = (png_byte)i; + conv = 1.; + } + + else + { + /* Convert 'i' from sRGB (45455) to real_gamma, this makes + * the images look the same regardless of the gAMA chunk. + */ + conv = real_gamma; + conv /= 45455; + + gamma_table[0] = 0; + + for (i=1; i<255; ++i) + gamma_table[i] = (png_byte)floor(pow(i/255.,conv) * 255 + .5); + + gamma_table[255] = 255; + } + } + + png_set_IHDR(png_ptr, info_ptr, size, size, bit_depth, color_type, + PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (color_type & PNG_COLOR_MASK_PALETTE) + { + int npalette; + png_color palette[256]; + png_byte trans[256]; + + npalette = generate_palette(palette, trans, bit_depth, gamma_table, + colors); + png_set_PLTE(png_ptr, info_ptr, palette, npalette); + png_set_tRNS(png_ptr, info_ptr, trans, npalette-1, + NULL/*transparent color*/); + + /* Reset gamma_table to prevent the image rows being changed */ + for (npalette=0; npalette<256; ++npalette) + gamma_table[npalette] = (png_byte)npalette; + } + + if (gamma == PNG_DEFAULT_sRGB) + png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE); + + else if (gamma > 0) /* Else don't set color space information */ + { + png_set_gAMA_fixed(png_ptr, info_ptr, real_gamma); + + /* Just use the sRGB values here. */ + png_set_cHRM_fixed(png_ptr, info_ptr, + /* color x y */ + /* white */ 31270, 32900, + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000 + ); + } + + /* Insert extra information. */ + while (insert != NULL) + { + insert->insert(png_ptr, info_ptr, insert->nparams, insert->parameters); + insert = insert->next; + } + + /* Write the file header. */ + png_write_info(png_ptr, info_ptr); + + /* Restrict the filters */ + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters); + + { + int passes = png_set_interlace_handling(png_ptr); + int pass; + png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + row = malloc(rowbytes); + + if (row == NULL) + png_error(png_ptr, "OOM allocating row buffer"); + + for (pass = 0; pass < passes; ++pass) + { + unsigned int y; + + for (y=0; y<size; ++y) + { + generate_row(row, rowbytes, y, color_type, bit_depth, + gamma_table, conv, colors); + png_write_row(png_ptr, row); + } + } + } + } + + /* Finish writing the file. */ + png_write_end(png_ptr, info_ptr); + + { + png_structp nv_ptr = png_ptr; + png_infop nv_info = info_ptr; + + png_ptr = NULL; + info_ptr = NULL; + png_destroy_write_struct(&nv_ptr, &nv_info); + } + free(row); + return 0; +} + + +static size_t +load_file(png_const_charp name, png_bytepp result) +{ + FILE *fp = tmpfile(); + + if (fp != NULL) + { + FILE *ip = fopen(name, "rb"); + + if (ip != NULL) + { + size_t total = 0; + int ch; + + for (;;) + { + ch = getc(ip); + if (ch == EOF) break; + putc(ch, fp); + ++total; + } + + if (ferror(ip)) + { + perror(name); + fprintf(stderr, "%s: read error\n", name); + (void)fclose(ip); + } + + else + { + (void)fclose(ip); + + if (ferror(fp)) + { + perror("temporary file"); + fprintf(stderr, "temporary file write error\n"); + } + + else + { + rewind(fp); + + if (total > 0) + { + /* Round up to a multiple of 4 here to allow an iCCP profile + * to be padded to a 4x boundary. + */ + png_bytep data = malloc((total+3)&~3); + + if (data != NULL) + { + size_t new_size = 0; + + for (;;) + { + ch = getc(fp); + if (ch == EOF) break; + data[new_size++] = (png_byte)ch; + } + + if (ferror(fp) || new_size != total) + { + perror("temporary file"); + fprintf(stderr, "temporary file read error\n"); + free(data); + } + + else + { + (void)fclose(fp); + *result = data; + return total; + } + } + + else + fprintf(stderr, "%s: out of memory loading file\n", name); + } + + else + fprintf(stderr, "%s: empty file\n", name); + } + } + } + + else + { + perror(name); + fprintf(stderr, "%s: open failed\n", name); + } + + fclose(fp); + } + + else + fprintf(stderr, "makepng: %s: could not open temporary file\n", name); + + exit(1); + return 0; +} + +static png_size_t +load_fake(png_charp param, png_bytepp profile) +{ + char *endptr = NULL; + unsigned long long int size = strtoull(param, &endptr, 0/*base*/); + + /* The 'fake' format is <number>*[string] */ + if (endptr != NULL && *endptr == '*') + { + size_t len = strlen(++endptr); + size_t result = (size_t)size; + + if (len == 0) len = 1; /* capture the terminating '\0' */ + + /* Now repeat that string to fill 'size' bytes. */ + if (result == size && (*profile = malloc(result)) != NULL) + { + png_bytep out = *profile; + + if (len == 1) + memset(out, *endptr, result); + + else + { + while (size >= len) + { + memcpy(out, endptr, len); + out += len; + size -= len; + } + memcpy(out, endptr, size); + } + + return result; + } + + else + { + fprintf(stderr, "%s: size exceeds system limits\n", param); + exit(1); + } + } + + return 0; +} + +static void +check_param_count(int nparams, int expect) +{ + if (nparams != expect) + { + fprintf(stderr, "bad parameter count (internal error)\n"); + exit(1); + } +} + +static void +insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_bytep profile = NULL; + png_uint_32 proflen = 0; + int result; + + check_param_count(nparams, 2); + + switch (params[1][0]) + { + case '<': + { + png_size_t filelen = load_file(params[1]+1, &profile); + if (filelen > 0xfffffffc) /* Maximum profile length */ + { + fprintf(stderr, "%s: file too long (%lu) for an ICC profile\n", + params[1]+1, (unsigned long)filelen); + exit(1); + } + + proflen = (png_uint_32)filelen; + } + break; + + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + { + png_size_t fake_len = load_fake(params[1], &profile); + + if (fake_len > 0) /* else a simple parameter */ + { + if (fake_len > 0xffffffff) /* Maximum profile length */ + { + fprintf(stderr, + "%s: fake data too long (%lu) for an ICC profile\n", + params[1], (unsigned long)fake_len); + exit(1); + } + proflen = (png_uint_32)(fake_len & ~3U); + /* Always fix up the profile length. */ + png_save_uint_32(profile, proflen); + break; + } + } + + default: + fprintf(stderr, "--insert iCCP \"%s\": unrecognized\n", params[1]); + fprintf(stderr, " use '<' to read a file: \"<filename\"\n"); + exit(1); + } + + result = 1; + + if (proflen & 3) + { + fprintf(stderr, + "makepng: --insert iCCP %s: profile length made a multiple of 4\n", + params[1]); + + /* load_file allocates extra space for this padding, the ICC spec requires + * padding with zero bytes. + */ + while (proflen & 3) + profile[proflen++] = 0; + } + + if (profile != NULL && proflen > 3) + { + png_uint_32 prof_header = png_get_uint_32(profile); + + if (prof_header != proflen) + { + fprintf(stderr, "--insert iCCP %s: profile length field wrong:\n", + params[1]); + fprintf(stderr, " actual %lu, recorded value %lu (corrected)\n", + (unsigned long)proflen, (unsigned long)prof_header); + png_save_uint_32(profile, proflen); + } + } + + if (result && profile != NULL && proflen >=4) + png_set_iCCP(png_ptr, info_ptr, params[0], PNG_COMPRESSION_TYPE_BASE, + profile, proflen); + + if (profile) + free(profile); + + if (!result) + exit(1); +} + +static void +clear_text(png_text *text, png_charp keyword) +{ + text->compression = -1; /* none */ + text->key = keyword; + text->text = NULL; + text->text_length = 0; /* libpng calculates this */ + text->itxt_length = 0; /* libpng calculates this */ + text->lang = NULL; + text->lang_key = NULL; +} + +static void +set_text(png_structp png_ptr, png_infop info_ptr, png_textp text, + png_charp param) +{ + switch (param[0]) + { + case '<': + { + png_bytep file = NULL; + + text->text_length = load_file(param+1, &file); + text->text = (png_charp)file; + } + break; + + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + { + png_bytep data = NULL; + png_size_t fake_len = load_fake(param, &data); + + if (fake_len > 0) /* else a simple parameter */ + { + text->text_length = fake_len; + text->text = (png_charp)data; + break; + } + } + + default: + text->text = param; + break; + } + + png_set_text(png_ptr, info_ptr, text, 1); + + if (text->text != param) + free(text->text); +} + +static void +insert_tEXt(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_text text; + + check_param_count(nparams, 2); + clear_text(&text, params[0]); + set_text(png_ptr, info_ptr, &text, params[1]); +} + +static void +insert_zTXt(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_text text; + + check_param_count(nparams, 2); + clear_text(&text, params[0]); + text.compression = 0; /* deflate */ + set_text(png_ptr, info_ptr, &text, params[1]); +} + +static void +insert_iTXt(png_structp png_ptr, png_infop info_ptr, int nparams, + png_charpp params) +{ + png_text text; + + check_param_count(nparams, 4); + clear_text(&text, params[0]); + text.compression = 2; /* iTXt + deflate */ + text.lang = params[1];/* language tag */ + text.lang_key = params[2]; /* translated keyword */ + set_text(png_ptr, info_ptr, &text, params[3]); +} + +static void +insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params) +{ + int i; + png_uint_16 freq[256]; + + /* libpng takes the count from the PLTE count; we don't check it here but we + * do set the array to 0 for unspecified entries. + */ + memset(freq, 0, sizeof freq); + for (i=0; i<nparams; ++i) + { + char *endptr = NULL; + unsigned long int l = strtoul(params[i], &endptr, 0/*base*/); + + if (params[i][0] && *endptr == 0 && l <= 65535) + freq[i] = (png_uint_16)l; + + else + { + fprintf(stderr, "hIST[%d]: %s: invalid frequency\n", i, params[i]); + exit(1); + } + } + + png_set_hIST(png_ptr, info_ptr, freq); +} + +#if 0 +static void +insert_sPLT(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params) +{ + fprintf(stderr, "insert sPLT: NYI\n"); +} +#endif + +static int +find_parameters(png_const_charp what, png_charp param, png_charp *list, + int nparams) +{ + /* Parameters are separated by '\n' or ':' characters, up to nparams are + * accepted (more is an error) and the number found is returned. + */ + int i; + for (i=0; *param && i<nparams; ++i) + { + list[i] = param; + while (*++param) if (*param == '\n' || *param == ':') + { + *param++ = 0; /* Terminate last parameter */ + break; /* And start a new one. */ + } + } + + if (*param) + { + fprintf(stderr, "--insert %s: too many parameters (%s)\n", what, param); + exit(1); + } + + list[i] = NULL; /* terminates list */ + return i; /* number of parameters filled in */ +} + +static void +bad_parameter_count(png_const_charp what, int nparams) +{ + fprintf(stderr, "--insert %s: bad parameter count %d\n", what, nparams); + exit(1); +} + +static chunk_insert * +make_insert(png_const_charp what, + void (*insert)(png_structp, png_infop, int, png_charpp), + int nparams, png_charpp list) +{ + int i; + chunk_insert *cip; + + cip = malloc(offsetof(chunk_insert,parameters) + + nparams * sizeof (png_charp)); + + if (cip == NULL) + { + fprintf(stderr, "--insert %s: out of memory allocating %d parameters\n", + what, nparams); + exit(1); + } + + cip->next = NULL; + cip->insert = insert; + cip->nparams = nparams; + for (i=0; i<nparams; ++i) + cip->parameters[i] = list[i]; + + return cip; +} + +static chunk_insert * +find_insert(png_const_charp what, png_charp param) +{ + png_uint_32 chunk = 0; + png_charp parameter_list[1024]; + int i, nparams; + + /* Assemble the chunk name */ + for (i=0; i<4; ++i) + { + char ch = what[i]; + + if ((ch >= 65 && ch <= 90) || (ch >= 97 && ch <= 122)) + chunk = (chunk << 8) + what[i]; + + else + break; + } + + if (i < 4 || what[4] != 0) + { + fprintf(stderr, "makepng --insert \"%s\": invalid chunk name\n", what); + exit(1); + } + + /* Assemble the parameter list. */ + nparams = find_parameters(what, param, parameter_list, 1024); + +# define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) + + switch (chunk) + { + case CHUNK(105,67,67,80): /* iCCP */ + if (nparams == 2) + return make_insert(what, insert_iCCP, nparams, parameter_list); + break; + + case CHUNK(116,69,88,116): /* tEXt */ + if (nparams == 2) + return make_insert(what, insert_tEXt, nparams, parameter_list); + break; + + case CHUNK(122,84,88,116): /* zTXt */ + if (nparams == 2) + return make_insert(what, insert_zTXt, nparams, parameter_list); + break; + + case CHUNK(105,84,88,116): /* iTXt */ + if (nparams == 4) + return make_insert(what, insert_iTXt, nparams, parameter_list); + break; + + case CHUNK(104,73,83,84): /* hIST */ + if (nparams <= 256) + return make_insert(what, insert_hIST, nparams, parameter_list); + break; + +#if 0 + case CHUNK(115,80,76,84): /* sPLT */ + return make_insert(what, insert_sPLT, nparams, parameter_list); +#endif + + default: + fprintf(stderr, "makepng --insert \"%s\": unrecognized chunk name\n", + what); + exit(1); + } + + bad_parameter_count(what, nparams); + return NULL; +} + +/* This is a not-very-good parser for a sequence of numbers (including 0). It + * doesn't accept some apparently valid things, but it accepts all the sensible + * combinations. + */ +static void +parse_color(char *arg, unsigned int *colors) +{ + unsigned int ncolors = 0; + + while (*arg && ncolors < 4) + { + char *ep = arg; + + unsigned long ul = strtoul(arg, &ep, 0); + + if (ul > 65535) + { + fprintf(stderr, "makepng --color=...'%s': too big\n", arg); + exit(1); + } + + if (ep == arg) + { + fprintf(stderr, "makepng --color=...'%s': not a valid color\n", arg); + exit(1); + } + + if (*ep) ++ep; /* skip a separator */ + arg = ep; + + colors[++ncolors] = (unsigned int)ul; /* checked above */ + } + + if (*arg) + { + fprintf(stderr, "makepng --color=...'%s': too many values\n", arg); + exit(1); + } + + *colors = ncolors; +} + +int +main(int argc, char **argv) +{ + FILE *fp = stdout; + const char *file_name = NULL; + int color_type = 8; /* invalid */ + int bit_depth = 32; /* invalid */ + unsigned int colors[5]; + unsigned int filters = PNG_ALL_FILTERS; + png_fixed_point gamma = 0; /* not set */ + chunk_insert *head_insert = NULL; + chunk_insert **insert_ptr = &head_insert; + + memset(colors, 0, sizeof colors); + + while (--argc > 0) + { + char *arg = *++argv; + + if (strcmp(arg, "--sRGB") == 0) + { + gamma = PNG_DEFAULT_sRGB; + continue; + } + + if (strcmp(arg, "--linear") == 0) + { + gamma = PNG_FP_1; + continue; + } + + if (strcmp(arg, "--1.8") == 0) + { + gamma = PNG_GAMMA_MAC_18; + continue; + } + + if (strcmp(arg, "--nofilters") == 0) + { + filters = PNG_FILTER_NONE; + continue; + } + + if (strncmp(arg, "--color=", 8) == 0) + { + parse_color(arg+8, colors); + continue; + } + + if (argc >= 3 && strcmp(arg, "--insert") == 0) + { + png_const_charp what = *++argv; + png_charp param = *++argv; + chunk_insert *new_insert; + + argc -= 2; + + new_insert = find_insert(what, param); + + if (new_insert != NULL) + { + *insert_ptr = new_insert; + insert_ptr = &new_insert->next; + } + + continue; + } + + if (arg[0] == '-') + { + fprintf(stderr, "makepng: %s: invalid option\n", arg); + exit(1); + } + + if (strcmp(arg, "palette") == 0) + { + color_type = PNG_COLOR_TYPE_PALETTE; + continue; + } + + if (strncmp(arg, "gray", 4) == 0) + { + if (arg[4] == 0) + { + color_type = PNG_COLOR_TYPE_GRAY; + continue; + } + + else if (strcmp(arg+4, "a") == 0 || + strcmp(arg+4, "alpha") == 0 || + strcmp(arg+4, "-alpha") == 0) + { + color_type = PNG_COLOR_TYPE_GRAY_ALPHA; + continue; + } + } + + if (strncmp(arg, "rgb", 3) == 0) + { + if (arg[3] == 0) + { + color_type = PNG_COLOR_TYPE_RGB; + continue; + } + + else if (strcmp(arg+3, "a") == 0 || + strcmp(arg+3, "alpha") == 0 || + strcmp(arg+3, "-alpha") == 0) + { + color_type = PNG_COLOR_TYPE_RGB_ALPHA; + continue; + } + } + + if (color_type == 8 && isdigit(arg[0])) + { + color_type = atoi(arg); + if (color_type < 0 || color_type > 6 || color_type == 1 || + color_type == 5) + { + fprintf(stderr, "makepng: %s: not a valid color type\n", arg); + exit(1); + } + + continue; + } + + if (bit_depth == 32 && isdigit(arg[0])) + { + bit_depth = atoi(arg); + if (bit_depth <= 0 || bit_depth > 16 || + (bit_depth & -bit_depth) != bit_depth) + { + fprintf(stderr, "makepng: %s: not a valid bit depth\n", arg); + exit(1); + } + + continue; + } + + if (argc == 1) /* It's the file name */ + { + fp = fopen(arg, "wb"); + if (fp == NULL) + { + fprintf(stderr, "%s: %s: could not open\n", arg, strerror(errno)); + exit(1); + } + + file_name = arg; + continue; + } + + fprintf(stderr, "makepng: %s: unknown argument\n", arg); + exit(1); + } /* argument while loop */ + + if (color_type == 8 || bit_depth == 32) + { + fprintf(stderr, "usage: makepng [--sRGB|--linear|--1.8] " + "[--color=...] color-type bit-depth [file-name]\n" + " Make a test PNG file, by default writes to stdout.\n"); + exit(1); + } + + /* Check the colors */ + { + const unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U : + (1U<<bit_depth)-1); + unsigned int i; + + for (i=1; i<=colors[0]; ++i) + if (colors[i] > lim) + { + fprintf(stderr, "makepng: --color=...: %u out of range [0..%u]\n", + colors[i], lim); + exit(1); + } + } + + /* Restrict the filters for more speed to those we know are used for the + * generated images. + */ + if (filters == PNG_ALL_FILTERS) + { + if ((color_type & PNG_COLOR_MASK_PALETTE) != 0 || bit_depth < 8) + filters = PNG_FILTER_NONE; + + else if (color_type & PNG_COLOR_MASK_COLOR) /* rgb */ + { + if (bit_depth == 8) + filters &= ~(PNG_FILTER_NONE | PNG_FILTER_AVG); + + else + filters = PNG_FILTER_SUB | PNG_FILTER_PAETH; + } + + else /* gray 8 or 16-bit */ + filters &= ~PNG_FILTER_NONE; + } + + { + int ret = write_png(&file_name, fp, color_type, bit_depth, gamma, + head_insert, filters, colors); + + if (ret != 0 && file_name != NULL) + remove(file_name); + + return ret; + } +} diff --git a/libpng/contrib/libtests/pngimage.c b/libpng/contrib/libtests/pngimage.c new file mode 100644 index 000000000..dccfbce12 --- /dev/null +++ b/libpng/contrib/libtests/pngimage.c @@ -0,0 +1,1652 @@ +/* pngimage.c + * + * Copyright (c) 2014 John Cunningham Bowler + * + * Last changed in libpng 1.6.10 [March 6, 2014] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Test the png_read_png and png_write_png interfaces. Given a PNG file load it + * using png_read_png and then write with png_write_png. Test all possible + * transforms. + */ +#include <stdarg.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <stdio.h> +#include <assert.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +#ifndef PNG_SETJMP_SUPPORTED +# include <setjmp.h> /* because png.h did *not* include this */ +#endif + +#if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED) +/* If a transform is valid on both read and write this implies that if the + * transform is applied to read it must also be applied on write to produce + * meaningful data. This is because these transforms when performed on read + * produce data with a memory format that does not correspond to a PNG format. + * + * Most of these transforms are invertible; after applying the transform on + * write the result is the original PNG data that would have would have been + * read if no transform were applied. + * + * The exception is _SHIFT, which destroys the low order bits marked as not + * significant in a PNG with the sBIT chunk. + * + * The following table lists, for each transform, the conditions under which it + * is expected to do anything. Conditions are defined as follows: + * + * 1) Color mask bits required - simply a mask to AND with color_type; one of + * these must be present for the transform to fire, except that 0 means + * 'always'. + * 2) Color mask bits which must be absent - another mask - none of these must + * be present. + * 3) Bit depths - a mask of component bit depths for the transform to fire. + * 4) 'read' - the transform works in png_read_png. + * 5) 'write' - the transform works in png_write_png. + * 6) PNG_INFO_chunk; a mask of the chunks that must be present for the + * transform to fire. All must be present - the requirement is that + * png_get_valid() & mask == mask, so if mask is 0 there is no requirement. + * + * The condition refers to the original image state - if multiple transforms are + * used together it is possible to cause a transform that wouldn't fire on the + * original image to fire. + */ +static struct transform_info +{ + const char *name; + int transform; + png_uint_32 valid_chunks; +# define CHUNK_NONE 0 +# define CHUNK_sBIT PNG_INFO_sBIT +# define CHUNK_tRNS PNG_INFO_tRNS + png_byte color_mask_required; + png_byte color_mask_absent; +# define COLOR_MASK_X 0 +# define COLOR_MASK_P PNG_COLOR_MASK_PALETTE +# define COLOR_MASK_C PNG_COLOR_MASK_COLOR +# define COLOR_MASK_A PNG_COLOR_MASK_ALPHA +# define COLOR_MASK_ALL (PALETTE+COLOR+ALPHA) /* absent = gray, no alpha */ + png_byte bit_depths; +# define BD_ALL (1 + 2 + 4 + 8 + 16) +# define BD_PAL (1 + 2 + 4 + 8) +# define BD_LOW (1 + 2 + 4) +# define BD_16 16 +# define BD_TRUE (8+16) /* i.e. true-color depths */ + png_byte when; +# define TRANSFORM_R 1 +# define TRANSFORM_W 2 +# define TRANSFORM_RW 3 + png_byte tested; /* the transform was tested somewhere */ +} transform_info[] = +{ + /* List ALL the PNG_TRANSFORM_ macros here. Check for support using the READ + * macros; even if the transform is supported on write it cannot be tested + * without the read support. + */ +# define T(name,chunk,cm_required,cm_absent,bd,when)\ + { #name, PNG_TRANSFORM_ ## name, CHUNK_ ## chunk,\ + COLOR_MASK_ ## cm_required, COLOR_MASK_ ## cm_absent, BD_ ## bd,\ + TRANSFORM_ ## when, 0/*!tested*/ } + +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED + T(STRIP_16, NONE, X, X, 16, R), + /* drops the bottom 8 bits when bit depth is 16 */ +#endif +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + T(STRIP_ALPHA, NONE, A, X, ALL, R), + /* removes the alpha channel if present */ +#endif +#ifdef PNG_WRITE_PACK_SUPPORTED +# define TRANSFORM_RW_PACK TRANSFORM_RW +#else +# define TRANSFORM_RW_PACK TRANSFORM_R +#endif +#ifdef PNG_READ_PACK_SUPPORTED + T(PACKING, NONE, X, X, LOW, RW_PACK), + /* unpacks low-bit-depth components into 1 byte per component on read, + * reverses this on write. + */ +#endif +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED +# define TRANSFORM_RW_PACKSWAP TRANSFORM_RW +#else +# define TRANSFORM_RW_PACKSWAP TRANSFORM_R +#endif +#ifdef PNG_READ_PACKSWAP_SUPPORTED + T(PACKSWAP, NONE, X, X, LOW, RW_PACKSWAP), + /* reverses the order of low-bit-depth components packed into a byte */ +#endif +#ifdef PNG_READ_EXPAND_SUPPORTED + T(EXPAND, NONE, P, X, ALL, R), + /* expands PLTE PNG files to RGB (no tRNS) or RGBA (tRNS) * + * Note that the 'EXPAND' transform does lots of different things: */ + T(EXPAND, NONE, X, C, ALL, R), + /* expands grayscale PNG files to RGB, or RGBA */ + T(EXPAND, tRNS, X, A, ALL, R), + /* expands the tRNS chunk in files without alpha */ +#endif +#ifdef PNG_WRITE_INVERT_SUPPORTED +# define TRANSFORM_RW_INVERT TRANSFORM_RW +#else +# define TRANSFORM_RW_INVERT TRANSFORM_R +#endif +#ifdef PNG_READ_INVERT_SUPPORTED + T(INVERT_MONO, NONE, X, C, ALL, RW_INVERT), + /* converts gray-scale components to 1..0 from 0..1 */ +#endif +#ifdef PNG_WRITE_SHIFT_SUPPORTED +# define TRANSFORM_RW_SHIFT TRANSFORM_RW +#else +# define TRANSFORM_RW_SHIFT TRANSFORM_R +#endif +#ifdef PNG_READ_SHIFT_SUPPORTED + T(SHIFT, sBIT, X, X, ALL, RW_SHIFT), + /* reduces component values to the original range based on the sBIT chunk, + * this is only partially reversible - the low bits are lost and cannot be + * recovered on write. In fact write code replicates the bits to generate + * new low-order bits. + */ +#endif +#ifdef PNG_WRITE_BGR_SUPPORTED +# define TRANSFORM_RW_BGR TRANSFORM_RW +#else +# define TRANSFORM_RW_BGR TRANSFORM_R +#endif +#ifdef PNG_READ_BGR_SUPPORTED + T(BGR, NONE, C, P, TRUE, RW_BGR), + /* reverses the rgb component values of true-color pixels */ +#endif +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED +# define TRANSFORM_RW_SWAP_ALPHA TRANSFORM_RW +#else +# define TRANSFORM_RW_SWAP_ALPHA TRANSFORM_R +#endif +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + T(SWAP_ALPHA, NONE, A, X, TRUE, RW_SWAP_ALPHA), + /* swaps the alpha channel of RGBA or GA pixels to the front - ARGB or + * AG, on write reverses the process. + */ +#endif +#ifdef PNG_WRITE_SWAP_SUPPORTED +# define TRANSFORM_RW_SWAP TRANSFORM_RW +#else +# define TRANSFORM_RW_SWAP TRANSFORM_R +#endif +#ifdef PNG_READ_SWAP_SUPPORTED + T(SWAP_ENDIAN, NONE, X, P, 16, RW_SWAP), + /* byte-swaps 16-bit component values */ +#endif +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED +# define TRANSFORM_RW_INVERT_ALPHA TRANSFORM_RW +#else +# define TRANSFORM_RW_INVERT_ALPHA TRANSFORM_R +#endif +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + T(INVERT_ALPHA, NONE, A, X, TRUE, RW_INVERT_ALPHA), + /* converts an alpha channel from 0..1 to 1..0 */ +#endif +#ifdef PNG_WRITE_FILLER_SUPPORTED + T(STRIP_FILLER_BEFORE, NONE, A, P, TRUE, W), /* 'A' for a filler! */ + /* on write skips a leading filler channel; testing requires data with a + * filler channel so this is produced from RGBA or GA images by removing + * the 'alpha' flag from the color type in place. + */ + T(STRIP_FILLER_AFTER, NONE, A, P, TRUE, W), + /* on write strips a trailing filler channel */ +#endif +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + T(GRAY_TO_RGB, NONE, X, C, ALL, R), + /* expands grayscale images to RGB, also causes the palette part of + * 'EXPAND' to happen. Low bit depth grayscale images are expanded to + * 8-bits per component and no attempt is made to convert the image to a + * palette image. While this transform is partially reversible + * png_write_png does not currently support this. + */ + T(GRAY_TO_RGB, NONE, P, X, ALL, R), + /* The 'palette' side effect mentioned above; a bit bogus but this is the + * way the libpng code works. + */ +#endif +#ifdef PNG_READ_EXPAND_16_SUPPORTED + T(EXPAND_16, NONE, X, X, PAL, R), + /* expands images to 16-bits per component, as a side effect expands + * palette images to RGB and expands the tRNS chunk if present, so it can + * modify 16-bit per component images as well: + */ + T(EXPAND_16, tRNS, X, A, 16, R), + /* side effect of EXPAND_16 - expands the tRNS chunk in an RGB or G 16-bit + * image. + */ +#endif +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + T(SCALE_16, NONE, X, X, 16, R) + /* scales 16-bit components to 8-bits. */ +#endif + +#undef T +}; + +#define ARRAY_SIZE(a) ((sizeof a)/(sizeof a[0])) +#define TTABLE_SIZE ARRAY_SIZE(transform_info) + +/* Some combinations of options that should be reversible are not; these cases + * are bugs. + */ +static int known_bad_combos[][2] = +{ + /* problem, antidote */ + { PNG_TRANSFORM_SHIFT | PNG_TRANSFORM_INVERT_ALPHA, 0/*antidote*/ } +}; + +static int +is_combo(int transforms) +{ + return transforms & (transforms-1); /* non-zero if more than one set bit */ +} + +static int +first_transform(int transforms) +{ + return transforms & -transforms; /* lowest set bit */ +} + +static int +is_bad_combo(int transforms) +{ + unsigned int i; + + for (i=0; i<ARRAY_SIZE(known_bad_combos); ++i) + { + int combo = known_bad_combos[i][0]; + + if ((combo & transforms) == combo && + (transforms & known_bad_combos[i][1]) == 0) + return 1; + } + + return 0; /* combo is ok */ +} + +static const char * +transform_name(int t) + /* The name, if 't' has multiple bits set the name of the lowest set bit is + * returned. + */ +{ + unsigned int i; + + t &= -t; /* first set bit */ + + for (i=0; i<TTABLE_SIZE; ++i) + { + if ((transform_info[i].transform & t) != 0) + return transform_info[i].name; + } + + return "invalid transform"; +} + +/* Variables calculated by validate_T below and used to record all the supported + * transforms. Need (unsigned int) here because of the places where these + * values are used (unsigned compares in the 'exhaustive' iterator.) + */ +static unsigned int read_transforms, write_transforms, rw_transforms; + +static void +validate_T(void) + /* Validate the above table - this just builds the above values */ +{ + unsigned int i; + + for (i=0; i<TTABLE_SIZE; ++i) + { + if (transform_info[i].when & TRANSFORM_R) + read_transforms |= transform_info[i].transform; + + if (transform_info[i].when & TRANSFORM_W) + write_transforms |= transform_info[i].transform; + } + + /* Reversible transforms are those which are supported on both read and + * write. + */ + rw_transforms = read_transforms & write_transforms; +} + +/* FILE DATA HANDLING + * The original file is cached in memory. During write the output file is + * written to memory. + * + * In both cases the file data is held in a linked list of buffers - not all + * of these are in use at any time. + */ +#define NEW(type) ((type *)malloc(sizeof (type))) +#define DELETE(ptr) (free(ptr)) + +struct buffer_list +{ + struct buffer_list *next; /* next buffer in list */ + png_byte buffer[1024]; /* the actual buffer */ +}; + +struct buffer +{ + struct buffer_list *last; /* last buffer in use */ + size_t end_count; /* bytes in the last buffer */ + struct buffer_list *current; /* current buffer being read */ + size_t read_count; /* count of bytes read from current */ + struct buffer_list first; /* the very first buffer */ +}; + +static void +buffer_init(struct buffer *buffer) + /* Call this only once for a given buffer */ +{ + buffer->first.next = NULL; + buffer->last = NULL; + buffer->current = NULL; +} + +static void +buffer_destroy_list(struct buffer_list *list) +{ + if (list != NULL) + { + struct buffer_list *next = list->next; + DELETE(list); + buffer_destroy_list(next); + } +} + +static void +buffer_destroy(struct buffer *buffer) +{ + struct buffer_list *list = buffer->first.next; + buffer_init(buffer); + buffer_destroy_list(list); +} + +#ifdef PNG_WRITE_SUPPORTED +static void +buffer_start_write(struct buffer *buffer) +{ + buffer->last = &buffer->first; + buffer->end_count = 0; + buffer->current = NULL; +} +#endif + +static void +buffer_start_read(struct buffer *buffer) +{ + buffer->current = &buffer->first; + buffer->read_count = 0; +} + +#ifdef ENOMEM /* required by POSIX 1003.1 */ +# define MEMORY ENOMEM +#else +# define MEMORY ERANGE /* required by ANSI-C */ +#endif +static struct buffer * +get_buffer(png_structp pp) + /* Used from libpng callbacks to get the current buffer */ +{ + return (struct buffer*)png_get_io_ptr(pp); +} + +static struct buffer_list * +buffer_extend(struct buffer_list *current) +{ + struct buffer_list *add; + + assert(current->next == NULL); + + add = NEW(struct buffer_list); + if (add == NULL) + return NULL; + + add->next = NULL; + current->next = add; + + return add; +} + +/* Load a buffer from a file; does the equivalent of buffer_start_write. On a + * read error returns an errno value, else returns 0. + */ +static int +buffer_from_file(struct buffer *buffer, FILE *fp) +{ + struct buffer_list *last = &buffer->first; + size_t count = 0; + + for (;;) + { + size_t r = fread(last->buffer+count, 1/*size*/, + (sizeof last->buffer)-count, fp); + + if (r > 0) + { + count += r; + + if (count >= sizeof last->buffer) + { + assert(count == sizeof last->buffer); + count = 0; + + if (last->next == NULL) + { + last = buffer_extend(last); + if (last == NULL) + return MEMORY; + } + + else + last = last->next; + } + } + + else /* fread failed - probably end of file */ + { + if (feof(fp)) + { + buffer->last = last; + buffer->end_count = count; + return 0; /* no error */ + } + + /* Some kind of funky error; errno should be non-zero */ + return errno == 0 ? ERANGE : errno; + } + } +} + +/* This structure is used to control the test of a single file. */ +typedef enum +{ + VERBOSE, /* switches on all messages */ + INFORMATION, + WARNINGS, /* switches on warnings */ + LIBPNG_WARNING, + APP_WARNING, + ERRORS, /* just errors */ + APP_FAIL, /* continuable error - no need to longjmp */ + LIBPNG_ERROR, /* this and higher cause a longjmp */ + LIBPNG_BUG, /* erroneous behavior in libpng */ + APP_ERROR, /* such as out-of-memory in a callback */ + QUIET, /* no normal messages */ + USER_ERROR, /* such as file-not-found */ + INTERNAL_ERROR +} error_level; +#define LEVEL_MASK 0xf /* where the level is in 'options' */ + +#define EXHAUSTIVE 0x010 /* Test all combinations of active options */ +#define STRICT 0x020 /* Fail on warnings as well as errors */ +#define LOG 0x040 /* Log pass/fail to stdout */ +#define CONTINUE 0x080 /* Continue on APP_FAIL errors */ +#define SKIP_BUGS 0x100 /* Skip over known bugs */ +#define LOG_SKIPPED 0x200 /* Log skipped bugs */ +#define FIND_BAD_COMBOS 0x400 /* Attempt to deduce bad combos */ + +/* Result masks apply to the result bits in the 'results' field below; these + * bits are simple 1U<<error_level. A pass requires either nothing worse than + * warnings (--relaxes) or nothing worse than information (--strict) + */ +#define RESULT_STRICT(r) (((r) & ~((1U<<WARNINGS)-1)) == 0) +#define RESULT_RELAXED(r) (((r) & ~((1U<<ERRORS)-1)) == 0) + +struct display +{ + jmp_buf error_return; /* Where to go to on error */ + + const char *filename; /* The name of the original file */ + const char *operation; /* Operation being performed */ + int transforms; /* Transform used in operation */ + png_uint_32 options; /* See display_log below */ + png_uint_32 results; /* A mask of errors seen */ + + + png_structp original_pp; /* used on the original read */ + png_infop original_ip; /* set by the original read */ + + png_size_t original_rowbytes; /* of the original rows: */ + png_bytepp original_rows; /* from the original read */ + + /* Original chunks valid */ + png_uint_32 chunks; + + /* Original IHDR information */ + png_uint_32 width; + png_uint_32 height; + int bit_depth; + int color_type; + int interlace_method; + int compression_method; + int filter_method; + + /* Derived information for the original image. */ + int active_transforms; /* transforms that do something on read */ + int ignored_transforms; /* transforms that should do nothing */ + + /* Used on a read, both the original read and when validating a written + * image. + */ + png_structp read_pp; + png_infop read_ip; + +# ifdef PNG_WRITE_SUPPORTED + /* Used to write a new image (the original info_ptr is used) */ + png_structp write_pp; + struct buffer written_file; /* where the file gets written */ +# endif + + struct buffer original_file; /* Data read from the original file */ +}; + +static void +display_init(struct display *dp) + /* Call this only once right at the start to initialize the control + * structure, the (struct buffer) lists are maintained across calls - the + * memory is not freed. + */ +{ + memset(dp, 0, sizeof *dp); + dp->options = WARNINGS; /* default to !verbose, !quiet */ + dp->filename = NULL; + dp->operation = NULL; + dp->original_pp = NULL; + dp->original_ip = NULL; + dp->original_rows = NULL; + dp->read_pp = NULL; + dp->read_ip = NULL; + buffer_init(&dp->original_file); + +# ifdef PNG_WRITE_SUPPORTED + dp->write_pp = NULL; + buffer_init(&dp->written_file); +# endif +} + +static void +display_clean_read(struct display *dp) +{ + if (dp->read_pp != NULL) + png_destroy_read_struct(&dp->read_pp, &dp->read_ip, NULL); +} + +#ifdef PNG_WRITE_SUPPORTED +static void +display_clean_write(struct display *dp) +{ + if (dp->write_pp != NULL) + png_destroy_write_struct(&dp->write_pp, NULL); +} +#endif + +static void +display_clean(struct display *dp) +{ +# ifdef PNG_WRITE_SUPPORTED + display_clean_write(dp); +# endif + display_clean_read(dp); + + dp->original_rowbytes = 0; + dp->original_rows = NULL; + dp->chunks = 0; + + png_destroy_read_struct(&dp->original_pp, &dp->original_ip, NULL); + /* leave the filename for error detection */ + dp->results = 0; /* reset for next time */ +} + +static void +display_destroy(struct display *dp) +{ + /* Release any memory held in the display. */ +# ifdef PNG_WRITE_SUPPORTED + buffer_destroy(&dp->written_file); +# endif + + buffer_destroy(&dp->original_file); +} + +static struct display * +get_dp(png_structp pp) + /* The display pointer is always stored in the png_struct error pointer */ +{ + struct display *dp = (struct display*)png_get_error_ptr(pp); + + if (dp == NULL) + { + fprintf(stderr, "pngimage: internal error (no display)\n"); + exit(99); /* prevents a crash */ + } + + return dp; +} + +/* error handling */ +#ifdef __GNUC__ +# define VGATTR __attribute__((__format__ (__printf__,3,4))) + /* Required to quiet GNUC warnings when the compiler sees a stdarg function + * that calls one of the stdio v APIs. + */ +#else +# define VGATTR +#endif +static void VGATTR +display_log(struct display *dp, error_level level, const char *fmt, ...) + /* 'level' is as above, fmt is a stdio style format string. This routine + * does not return if level is above LIBPNG_WARNING + */ +{ + dp->results |= 1U << level; + + if (level > (error_level)(dp->options & LEVEL_MASK)) + { + const char *lp; + va_list ap; + + switch (level) + { + case INFORMATION: lp = "information"; break; + case LIBPNG_WARNING: lp = "warning(libpng)"; break; + case APP_WARNING: lp = "warning(pngimage)"; break; + case APP_FAIL: lp = "error(continuable)"; break; + case LIBPNG_ERROR: lp = "error(libpng)"; break; + case LIBPNG_BUG: lp = "bug(libpng)"; break; + case APP_ERROR: lp = "error(pngimage)"; break; + case USER_ERROR: lp = "error(user)"; break; + + case INTERNAL_ERROR: /* anything unexpected is an internal error: */ + case VERBOSE: case WARNINGS: case ERRORS: case QUIET: + default: lp = "bug(pngimage)"; break; + } + + fprintf(stderr, "%s: %s: %s", + dp->filename != NULL ? dp->filename : "<stdin>", lp, dp->operation); + + if (dp->transforms != 0) + { + int tr = dp->transforms; + + if (is_combo(tr)) + fprintf(stderr, "(0x%x)", tr); + + else + fprintf(stderr, "(%s)", transform_name(tr)); + } + + fprintf(stderr, ": "); + + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + + fputc('\n', stderr); + } + /* else do not output any message */ + + /* Errors cause this routine to exit to the fail code */ + if (level > APP_FAIL || (level > ERRORS && !(dp->options & CONTINUE))) + longjmp(dp->error_return, level); +} + +/* error handler callbacks for libpng */ +static void PNGCBAPI +display_warning(png_structp pp, png_const_charp warning) +{ + display_log(get_dp(pp), LIBPNG_WARNING, "%s", warning); +} + +static void PNGCBAPI +display_error(png_structp pp, png_const_charp error) +{ + struct display *dp = get_dp(pp); + + display_log(dp, LIBPNG_ERROR, "%s", error); +} + +static void +display_cache_file(struct display *dp, const char *filename) + /* Does the initial cache of the file. */ +{ + FILE *fp; + int ret; + + dp->filename = filename; + + if (filename != NULL) + { + fp = fopen(filename, "rb"); + if (fp == NULL) + display_log(dp, USER_ERROR, "open failed: %s", strerror(errno)); + } + + else + fp = stdin; + + ret = buffer_from_file(&dp->original_file, fp); + + fclose(fp); + + if (ret != 0) + display_log(dp, APP_ERROR, "read failed: %s", strerror(ret)); +} + +static void +buffer_read(struct display *dp, struct buffer *bp, png_bytep data, + png_size_t size) +{ + struct buffer_list *last = bp->current; + size_t read_count = bp->read_count; + + while (size > 0) + { + size_t avail; + + if (last == NULL || + (last == bp->last && read_count >= bp->end_count)) + { + display_log(dp, USER_ERROR, "file truncated (%lu bytes)", + (unsigned long)size); + /*NOTREACHED*/ + break; + } + + else if (read_count >= sizeof last->buffer) + { + /* Move to the next buffer: */ + last = last->next; + read_count = 0; + bp->current = last; /* Avoid update outside the loop */ + + /* And do a sanity check (the EOF case is caught above) */ + if (last == NULL) + { + display_log(dp, INTERNAL_ERROR, "damaged buffer list"); + /*NOTREACHED*/ + break; + } + } + + avail = (sizeof last->buffer) - read_count; + if (avail > size) + avail = size; + + memcpy(data, last->buffer + read_count, avail); + read_count += avail; + size -= avail; + data += avail; + } + + bp->read_count = read_count; +} + +static void PNGCBAPI +read_function(png_structp pp, png_bytep data, png_size_t size) +{ + buffer_read(get_dp(pp), get_buffer(pp), data, size); +} + +static void +read_png(struct display *dp, struct buffer *bp, const char *operation, + int transforms) +{ + png_structp pp; + png_infop ip; + + /* This cleans out any previous read and sets operation and transforms to + * empty. + */ + display_clean_read(dp); + + if (operation != NULL) /* else this is a verify and do not overwrite info */ + { + dp->operation = operation; + dp->transforms = transforms; + } + + dp->read_pp = pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, dp, + display_error, display_warning); + if (pp == NULL) + display_log(dp, LIBPNG_ERROR, "failed to create read struct"); + + /* The png_read_png API requires us to make the info struct, but it does the + * call to png_read_info. + */ + dp->read_ip = ip = png_create_info_struct(pp); + if (ip == NULL) + display_log(dp, LIBPNG_ERROR, "failed to create info struct"); + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + /* Remove the user limits, if any */ + png_set_user_limits(pp, 0x7fffffff, 0x7fffffff); +# endif + + /* Set the IO handling */ + buffer_start_read(bp); + png_set_read_fn(pp, bp, read_function); + + png_read_png(pp, ip, transforms, NULL/*params*/); + +#if 0 /* crazy debugging */ + { + png_bytep pr = png_get_rows(pp, ip)[0]; + size_t rb = png_get_rowbytes(pp, ip); + size_t cb; + char c = ' '; + + fprintf(stderr, "%.4x %2d (%3lu bytes):", transforms, png_get_bit_depth(pp,ip), (unsigned long)rb); + + for (cb=0; cb<rb; ++cb) + fputc(c, stderr), fprintf(stderr, "%.2x", pr[cb]), c='.'; + + fputc('\n', stderr); + } +#endif +} + +static void +update_display(struct display *dp) + /* called once after the first read to update all the info, original_pp and + * original_ip must have been filled in. + */ +{ + png_structp pp; + png_infop ip; + + /* Now perform the initial read with a 0 tranform. */ + read_png(dp, &dp->original_file, "original read", 0/*no transform*/); + + /* Move the result to the 'original' fields */ + dp->original_pp = pp = dp->read_pp, dp->read_pp = NULL; + dp->original_ip = ip = dp->read_ip, dp->read_ip = NULL; + + dp->original_rowbytes = png_get_rowbytes(pp, ip); + if (dp->original_rowbytes == 0) + display_log(dp, LIBPNG_BUG, "png_get_rowbytes returned 0"); + + dp->chunks = png_get_valid(pp, ip, 0xffffffff); + if ((dp->chunks & PNG_INFO_IDAT) == 0) /* set by png_read_png */ + display_log(dp, LIBPNG_BUG, "png_read_png did not set IDAT flag"); + + dp->original_rows = png_get_rows(pp, ip); + if (dp->original_rows == NULL) + display_log(dp, LIBPNG_BUG, "png_read_png did not create row buffers"); + + if (!png_get_IHDR(pp, ip, + &dp->width, &dp->height, &dp->bit_depth, &dp->color_type, + &dp->interlace_method, &dp->compression_method, &dp->filter_method)) + display_log(dp, LIBPNG_BUG, "png_get_IHDR failed"); + + /* 'active' transforms are discovered based on the original image format; + * running one active transform can activate others. At present the code + * does not attempt to determine the closure. + */ + { + png_uint_32 chunks = dp->chunks; + int active = 0, inactive = 0; + int ct = dp->color_type; + int bd = dp->bit_depth; + unsigned int i; + + for (i=0; i<TTABLE_SIZE; ++i) + { + int transform = transform_info[i].transform; + + if ((transform_info[i].valid_chunks == 0 || + (transform_info[i].valid_chunks & chunks) != 0) && + (transform_info[i].color_mask_required & ct) == + transform_info[i].color_mask_required && + (transform_info[i].color_mask_absent & ct) == 0 && + (transform_info[i].bit_depths & bd) != 0 && + (transform_info[i].when & TRANSFORM_R) != 0) + active |= transform; + + else if ((transform_info[i].when & TRANSFORM_R) != 0) + inactive |= transform; + } + + /* Some transforms appear multiple times in the table; the 'active' status + * is the logical OR of these and the inactive status must be adjusted to + * take this into account. + */ + inactive &= ~active; + + dp->active_transforms = active; + dp->ignored_transforms = inactive; /* excluding write-only transforms */ + + if (active == 0) + display_log(dp, INTERNAL_ERROR, "bad transform table"); + } +} + +static int +compare_read(struct display *dp, int applied_transforms) +{ + /* Compare the png_info from read_ip with original_info */ + size_t rowbytes; + png_uint_32 width, height; + int bit_depth, color_type; + int interlace_method, compression_method, filter_method; + const char *e = NULL; + + png_get_IHDR(dp->read_pp, dp->read_ip, &width, &height, &bit_depth, + &color_type, &interlace_method, &compression_method, &filter_method); + +# define C(item) if (item != dp->item) \ + display_log(dp, APP_WARNING, "IHDR " #item "(%lu) changed to %lu",\ + (unsigned long)dp->item, (unsigned long)item), e = #item + + /* The IHDR should be identical: */ + C(width); + C(height); + C(bit_depth); + C(color_type); + C(interlace_method); + C(compression_method); + C(filter_method); + + /* 'e' remains set to the name of the last thing changed: */ + if (e) + display_log(dp, APP_ERROR, "IHDR changed (%s)", e); + + /* All the chunks from the original PNG should be preserved in the output PNG + * because the PNG format has not been changed. + */ + { + unsigned long chunks = + png_get_valid(dp->read_pp, dp->read_ip, 0xffffffff); + + if (chunks != dp->chunks) + display_log(dp, APP_FAIL, "PNG chunks changed from 0x%lx to 0x%lx", + (unsigned long)dp->chunks, chunks); + } + + /* rowbytes should be the same */ + rowbytes = png_get_rowbytes(dp->read_pp, dp->read_ip); + + /* NOTE: on 64-bit systems this may trash the top bits of rowbytes, + * which could lead to weird error messages. + */ + if (rowbytes != dp->original_rowbytes) + display_log(dp, APP_ERROR, "PNG rowbytes changed from %lu to %lu", + (unsigned long)dp->original_rowbytes, (unsigned long)rowbytes); + + /* The rows should be the same too, unless the applied transforms includes + * the shift transform, in which case low bits may have been lost. + */ + { + png_bytepp rows = png_get_rows(dp->read_pp, dp->read_ip); + unsigned int mask; /* mask (if not zero) for the final byte */ + + if (bit_depth < 8) + { + /* Need the stray bits at the end, this depends only on the low bits + * of the image width; overflow does not matter. If the width is an + * exact multiple of 8 bits this gives a mask of 0, not 0xff. + */ + mask = 0xff & (0xff00 >> ((bit_depth * width) & 7)); + } + + else + mask = 0; + + if (rows == NULL) + display_log(dp, LIBPNG_BUG, "png_get_rows returned NULL"); + + if ((applied_transforms & PNG_TRANSFORM_SHIFT) == 0 || + (dp->active_transforms & PNG_TRANSFORM_SHIFT) == 0 || + color_type == PNG_COLOR_TYPE_PALETTE) + { + unsigned long y; + + for (y=0; y<height; ++y) + { + png_bytep row = rows[y]; + png_bytep orig = dp->original_rows[y]; + + if (memcmp(row, orig, rowbytes-(mask != 0)) != 0 || (mask != 0 && + ((row[rowbytes-1] & mask) != (orig[rowbytes-1] & mask)))) + { + size_t x; + + /* Find the first error */ + for (x=0; x<rowbytes-1; ++x) if (row[x] != orig[x]) + break; + + display_log(dp, APP_FAIL, + "byte(%lu,%lu) changed 0x%.2x -> 0x%.2x", + (unsigned long)x, (unsigned long)y, orig[x], row[x]); + return 0; /* don't keep reporting failed rows on 'continue' */ + } + } + } + + else + { + unsigned long y; + int bpp; /* bits-per-pixel then bytes-per-pixel */ + /* components are up to 8 bytes in size */ + png_byte sig_bits[8]; + png_color_8p sBIT; + + if (png_get_sBIT(dp->read_pp, dp->read_ip, &sBIT) != PNG_INFO_sBIT) + display_log(dp, INTERNAL_ERROR, + "active shift transform but no sBIT in file"); + + switch (color_type) + { + case PNG_COLOR_TYPE_GRAY: + sig_bits[0] = sBIT->gray; + bpp = bit_depth; + break; + + case PNG_COLOR_TYPE_GA: + sig_bits[0] = sBIT->gray; + sig_bits[1] = sBIT->alpha; + bpp = 2 * bit_depth; + break; + + case PNG_COLOR_TYPE_RGB: + sig_bits[0] = sBIT->red; + sig_bits[1] = sBIT->green; + sig_bits[2] = sBIT->blue; + bpp = 3 * bit_depth; + break; + + case PNG_COLOR_TYPE_RGBA: + sig_bits[0] = sBIT->red; + sig_bits[1] = sBIT->green; + sig_bits[2] = sBIT->blue; + sig_bits[3] = sBIT->alpha; + bpp = 4 * bit_depth; + break; + + default: + display_log(dp, LIBPNG_ERROR, "invalid colour type %d", + color_type); + /*NOTREACHED*/ + bpp = 0; + break; + } + + { + int b; + + for (b=0; 8*b<bpp; ++b) + { + /* libpng should catch this; if not there is a security issue + * because an app (like this one) may overflow an array. In fact + * libpng doesn't catch this at present. + */ + if (sig_bits[b] == 0 || sig_bits[b] > bit_depth/*!palette*/) + display_log(dp, LIBPNG_BUG, + "invalid sBIT[%u] value %d returned for PNG bit depth %d", + b, sig_bits[b], bit_depth); + } + } + + if (bpp < 8 && bpp != bit_depth) + { + /* sanity check; this is a grayscale PNG; something is wrong in the + * code above. + */ + display_log(dp, INTERNAL_ERROR, "invalid bpp %u for bit_depth %u", + bpp, bit_depth); + } + + switch (bit_depth) + { + int b; + + case 16: /* Two bytes per component, bit-endian */ + for (b = (bpp >> 4); b > 0; ) + { + unsigned int sig = (unsigned int)(0xffff0000 >> sig_bits[b]); + + sig_bits[2*b+1] = (png_byte)sig; + sig_bits[2*b+0] = (png_byte)(sig >> 8); /* big-endian */ + } + break; + + case 8: /* One byte per component */ + for (b=0; b*8 < bpp; ++b) + sig_bits[b] = (png_byte)(0xff00 >> sig_bits[b]); + break; + + case 1: /* allowed, but dumb */ + /* Value is 1 */ + sig_bits[0] = 0xff; + break; + + case 2: /* Replicate 4 times */ + /* Value is 1 or 2 */ + b = 0x3 & ((0x3<<2) >> sig_bits[0]); + b |= b << 2; + b |= b << 4; + sig_bits[0] = (png_byte)b; + break; + + case 4: /* Relicate twice */ + /* Value is 1, 2, 3 or 4 */ + b = 0xf & ((0xf << 4) >> sig_bits[0]); + b |= b << 4; + sig_bits[0] = (png_byte)b; + break; + + default: + display_log(dp, LIBPNG_BUG, "invalid bit depth %d", bit_depth); + break; + } + + /* Convert bpp to bytes; this gives '1' for low-bit depth grayscale, + * where there are multiple pixels per byte. + */ + bpp = (bpp+7) >> 3; + + /* The mask can be combined with sig_bits[0] */ + if (mask != 0) + { + mask &= sig_bits[0]; + + if (bpp != 1 || mask == 0) + display_log(dp, INTERNAL_ERROR, "mask calculation error %u, %u", + bpp, mask); + } + + for (y=0; y<height; ++y) + { + png_bytep row = rows[y]; + png_bytep orig = dp->original_rows[y]; + unsigned long x; + + for (x=0; x<(width-(mask!=0)); ++x) + { + int b; + + for (b=0; b<bpp; ++b) + { + if ((*row++ & sig_bits[b]) != (*orig++ & sig_bits[b])) + { + display_log(dp, APP_FAIL, + "significant bits at (%lu[%u],%lu) changed %.2x->%.2x", + x, b, y, orig[-1], row[-1]); + return 0; + } + } + } + + if (mask != 0 && (*row & mask) != (*orig & mask)) + { + display_log(dp, APP_FAIL, + "significant bits at (%lu[end],%lu) changed", x, y); + return 0; + } + } /* for y */ + } + } + + return 1; /* compare succeeded */ +} + +#ifdef PNG_WRITE_SUPPORTED +static void +buffer_write(struct display *dp, struct buffer *buffer, png_bytep data, + png_size_t size) + /* Generic write function used both from the write callback provided to + * libpng and from the generic read code. + */ +{ + /* Write the data into the buffer, adding buffers as required */ + struct buffer_list *last = buffer->last; + size_t end_count = buffer->end_count; + + while (size > 0) + { + size_t avail; + + if (end_count >= sizeof last->buffer) + { + if (last->next == NULL) + { + last = buffer_extend(last); + + if (last == NULL) + display_log(dp, APP_ERROR, "out of memory saving file"); + } + + else + last = last->next; + + buffer->last = last; /* avoid the need to rewrite every time */ + end_count = 0; + } + + avail = (sizeof last->buffer) - end_count; + if (avail > size) + avail = size; + + memcpy(last->buffer + end_count, data, avail); + end_count += avail; + size -= avail; + data += avail; + } + + buffer->end_count = end_count; +} + +static void PNGCBAPI +write_function(png_structp pp, png_bytep data, png_size_t size) +{ + buffer_write(get_dp(pp), get_buffer(pp), data, size); +} + +static void +write_png(struct display *dp, png_infop ip, int transforms) +{ + display_clean_write(dp); /* safety */ + + buffer_start_write(&dp->written_file); + dp->operation = "write"; + dp->transforms = transforms; + + dp->write_pp = png_create_write_struct(PNG_LIBPNG_VER_STRING, dp, + display_error, display_warning); + + if (dp->write_pp == NULL) + display_log(dp, APP_ERROR, "failed to create write png_struct"); + + png_set_write_fn(dp->write_pp, &dp->written_file, write_function, + NULL/*flush*/); + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + /* Remove the user limits, if any */ + png_set_user_limits(dp->write_pp, 0x7fffffff, 0x7fffffff); +# endif + + /* Certain transforms require the png_info to be zapped to allow the + * transform to work correctly. + */ + if (transforms & (PNG_TRANSFORM_PACKING| + PNG_TRANSFORM_STRIP_FILLER| + PNG_TRANSFORM_STRIP_FILLER_BEFORE)) + { + int ct = dp->color_type; + + if (transforms & (PNG_TRANSFORM_STRIP_FILLER| + PNG_TRANSFORM_STRIP_FILLER_BEFORE)) + ct &= ~PNG_COLOR_MASK_ALPHA; + + png_set_IHDR(dp->write_pp, ip, dp->width, dp->height, dp->bit_depth, ct, + dp->interlace_method, dp->compression_method, dp->filter_method); + } + + png_write_png(dp->write_pp, ip, transforms, NULL/*params*/); + + /* Clean it on the way out - if control returns to the caller then the + * written_file contains the required data. + */ + display_clean_write(dp); +} +#endif /* WRITE_SUPPORTED */ + +static int +skip_transform(struct display *dp, int tr) + /* Helper to test for a bad combo and log it if it is skipped */ +{ + if ((dp->options & SKIP_BUGS) != 0 && is_bad_combo(tr)) + { + /* Log this to stdout if logging is on, otherwise just do an information + * display_log. + */ + if ((dp->options & LOG_SKIPPED) != 0) + { + printf("SKIP: %s transforms ", dp->filename); + + while (tr != 0) + { + int next = first_transform(tr); + tr &= ~next; + + printf("%s", transform_name(next)); + if (tr != 0) + putchar('+'); + } + + putchar('\n'); + } + + else + display_log(dp, INFORMATION, "%s: skipped known bad combo 0x%x", + dp->filename, tr); + + return 1; /* skip */ + } + + return 0; /* don't skip */ +} + +static void +test_one_file(struct display *dp, const char *filename) +{ + /* First cache the file and update the display original file + * information for the new file. + */ + dp->operation = "cache file"; + dp->transforms = 0; + display_cache_file(dp, filename); + update_display(dp); + + /* First test: if there are options that should be ignored for this file + * verify that they really are ignored. + */ + if (dp->ignored_transforms != 0) + { + read_png(dp, &dp->original_file, "ignored transforms", + dp->ignored_transforms); + + /* The result should be identical to the original_rows */ + if (!compare_read(dp, 0/*transforms applied*/)) + return; /* no point testing more */ + } + +#ifdef PNG_WRITE_SUPPORTED + /* Second test: write the original PNG data out to a new file (to test the + * write side) then read the result back in and make sure that it hasn't + * changed. + */ + dp->operation = "write"; + write_png(dp, dp->original_ip, 0/*transforms*/); + read_png(dp, &dp->written_file, NULL, 0/*transforms*/); + if (!compare_read(dp, 0/*transforms applied*/)) + return; +#endif + + /* Third test: the active options. Test each in turn, or, with the + * EXHAUSTIVE option, test all possible combinations. + */ + { + /* Use unsigned int here because the code below to increment through all + * the possibilities exhaustively has to use a compare and that must be + * unsigned, because some transforms are negative on a 16-bit system. + */ + unsigned int active = dp->active_transforms; + const int exhaustive = (dp->options & EXHAUSTIVE) != 0; + unsigned int current = first_transform(active); + unsigned int bad_transforms = 0; + unsigned int bad_combo = ~0U; /* bitwise AND of failing transforms */ + unsigned int bad_combo_list = 0; /* bitwise OR of failures */ + + for (;;) + { + read_png(dp, &dp->original_file, "active transforms", current); + + /* If this involved any irreversible transformations then if we write + * it out with just the reversible transformations and read it in again + * with the same transforms we should get the same thing. At present + * this isn't done - it just seems like a waste of time and it would + * require two sets of read png_struct/png_info. + * + * If there were no irreversible transformations then if we write it + * out and read it back in again (without the reversible transforms) + * we should get back to the place where we started. + */ +#ifdef PNG_WRITE_SUPPORTED + if ((current & write_transforms) == current) + { + /* All transforms reversible: write the PNG with the transformations + * reversed, then read it back in with no transformations. The + * result should be the same as the original apart from the loss of + * low order bits because of the SHIFT/sBIT transform. + */ + dp->operation = "reversible transforms"; + write_png(dp, dp->read_ip, current); + + /* And if this is read back in, because all the transformations were + * reversible, the result should be the same. + */ + read_png(dp, &dp->written_file, NULL, 0); + if (!compare_read(dp, current/*for the SHIFT/sBIT transform*/)) + { + /* This set of transforms failed. If a single bit is set - if + * there is just one transform - don't include this in further + * 'exhaustive' tests. Notice that each transform is tested on + * its own before testing combos in the exhaustive case. + */ + if (is_combo(current)) + { + bad_combo &= current; + bad_combo_list |= current; + } + + else + bad_transforms |= current; + } + } +#endif + + /* Now move to the next transform */ + if (exhaustive) /* all combinations */ + { + unsigned int next = current; + + do + { + if (next == read_transforms) /* Everything tested */ + goto combo; + + ++next; + } /* skip known bad combos if the relevant option is set; skip + * combos involving known bad single transforms in all cases. + */ + while ( (next & read_transforms) <= current + || (next & active) == 0 /* skip cases that do nothing */ + || (next & bad_transforms) != 0 + || skip_transform(dp, next)); + + assert((next & read_transforms) == next); + current = next; + } + + else /* one at a time */ + { + active &= ~current; + + if (active == 0) + goto combo; + + current = first_transform(active); + } + } + +combo: + if (dp->options & FIND_BAD_COMBOS) + { + /* bad_combos identifies the combos that occur in all failing cases; + * bad_combo_list identifies transforms that do not prevent the + * failure. + */ + if (bad_combo != ~0U) + printf("%s[0x%x]: PROBLEM: 0x%x[0x%x] ANTIDOTE: 0x%x\n", + dp->filename, active, bad_combo, bad_combo_list, + rw_transforms & ~bad_combo_list); + + else + printf("%s: no %sbad combos found\n", dp->filename, + (dp->options & SKIP_BUGS) ? "additional " : ""); + } + } +} + +static int +do_test(struct display *dp, const char *file) + /* Exists solely to isolate the setjmp clobbers */ +{ + int ret = setjmp(dp->error_return); + + if (ret == 0) + { + test_one_file(dp, file); + return 0; + } + + else if (ret < ERRORS) /* shouldn't longjmp on warnings */ + display_log(dp, INTERNAL_ERROR, "unexpected return code %d", ret); + + return ret; +} + +int +main(const int argc, const char * const * const argv) +{ + /* For each file on the command line test it with a range of transforms */ + int option_end, ilog = 0; + struct display d; + + validate_T(); + display_init(&d); + + for (option_end=1; option_end<argc; ++option_end) + { + const char *name = argv[option_end]; + + if (strcmp(name, "--verbose") == 0) + d.options = (d.options & ~LEVEL_MASK) | VERBOSE; + + else if (strcmp(name, "--warnings") == 0) + d.options = (d.options & ~LEVEL_MASK) | WARNINGS; + + else if (strcmp(name, "--errors") == 0) + d.options = (d.options & ~LEVEL_MASK) | ERRORS; + + else if (strcmp(name, "--quiet") == 0) + d.options = (d.options & ~LEVEL_MASK) | QUIET; + + else if (strcmp(name, "--exhaustive") == 0) + d.options |= EXHAUSTIVE; + + else if (strcmp(name, "--fast") == 0) + d.options &= ~EXHAUSTIVE; + + else if (strcmp(name, "--strict") == 0) + d.options |= STRICT; + + else if (strcmp(name, "--relaxed") == 0) + d.options &= ~STRICT; + + else if (strcmp(name, "--log") == 0) + { + ilog = option_end; /* prevent display */ + d.options |= LOG; + } + + else if (strcmp(name, "--nolog") == 0) + d.options &= ~LOG; + + else if (strcmp(name, "--continue") == 0) + d.options |= CONTINUE; + + else if (strcmp(name, "--stop") == 0) + d.options &= ~CONTINUE; + + else if (strcmp(name, "--skip-bugs") == 0) + d.options |= SKIP_BUGS; + + else if (strcmp(name, "--test-all") == 0) + d.options &= ~SKIP_BUGS; + + else if (strcmp(name, "--log-skipped") == 0) + d.options |= LOG_SKIPPED; + + else if (strcmp(name, "--nolog-skipped") == 0) + d.options &= ~LOG_SKIPPED; + + else if (strcmp(name, "--find-bad-combos") == 0) + d.options |= FIND_BAD_COMBOS; + + else if (strcmp(name, "--nofind-bad-combos") == 0) + d.options &= ~FIND_BAD_COMBOS; + + else if (name[0] == '-' && name[1] == '-') + { + fprintf(stderr, "pngimage: %s: unknown option\n", name); + return 99; + } + + else + break; /* Not an option */ + } + + { + int i; + int errors = 0; + + for (i=option_end; i<argc; ++i) + { + { + int ret = do_test(&d, argv[i]); + + if (ret > QUIET) /* abort on user or internal error */ + return 99; + } + + /* Here on any return, including failures, except user/internal issues + */ + { + const int pass = (d.options & STRICT) ? + RESULT_STRICT(d.results) : RESULT_RELAXED(d.results); + + if (!pass) + ++errors; + + if (d.options & LOG) + { + int j; + + printf("%s: pngimage ", pass ? "PASS" : "FAIL"); + + for (j=1; j<option_end; ++j) if (j != ilog) + printf("%s ", argv[j]); + + printf("%s\n", d.filename); + } + } + + display_clean(&d); + } + + /* Release allocated memory */ + display_destroy(&d); + + return errors != 0; + } +} +#else /* !PNG_INFO_IMAGE_SUPPORTED || !PNG_READ_SUPPORTED */ +int +main(void) +{ + fprintf(stderr, "pngimage: no support for png_read/write_image\n"); + return 77; +} +#endif diff --git a/libpng/contrib/libtests/pngstest.c b/libpng/contrib/libtests/pngstest.c new file mode 100644 index 000000000..d7c1c1e79 --- /dev/null +++ b/libpng/contrib/libtests/pngstest.c @@ -0,0 +1,3818 @@ +/*- + * pngstest.c + * + * Copyright (c) 2013-2014 John Cunningham Bowler + * + * Last changed in libpng 1.6.16 [December 22, 2014] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Test for the PNG 'simplified' APIs. + */ +#define _ISOC90_SOURCE 1 +#define MALLOC_CHECK_ 2/*glibc facility: turn on debugging*/ + +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <errno.h> +#include <ctype.h> +#include <math.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +#ifdef PNG_SIMPLIFIED_READ_SUPPORTED /* Else nothing can be done */ +#include "../tools/sRGB.h" + +/* KNOWN ISSUES + * + * These defines switch on alternate algorithms for format conversions to match + * the current libpng implementation; they are set to allow pngstest to pass + * even though libpng is producing answers that are not as correct as they + * should be. + */ +#define ALLOW_UNUSED_GPC 0 + /* If true include unused static GPC functions and declare an external array + * of them to hide the fact that they are unused. This is for development + * use while testing the correct function to use to take into account libpng + * misbehavior, such as using a simple power law to correct sRGB to linear. + */ + +/* The following is to support direct compilation of this file as C++ */ +#ifdef __cplusplus +# define voidcast(type, value) static_cast<type>(value) +# define aligncastconst(type, value) \ + static_cast<type>(static_cast<const void*>(value)) +#else +# define voidcast(type, value) (value) +# define aligncastconst(type, value) ((const void*)(value)) +#endif /* __cplusplus */ + +/* During parallel runs of pngstest each temporary file needs a unique name, + * this is used to permit uniqueness using a command line argument which can be + * up to 22 characters long. + */ +static char tmpf[23] = "TMP"; + +/* Generate random bytes. This uses a boring repeatable algorithm and it + * is implemented here so that it gives the same set of numbers on every + * architecture. It's a linear congruential generator (Knuth or Sedgewick + * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and + * Hill, "The Art of Electronics". + */ +static void +make_random_bytes(png_uint_32* seed, void* pv, size_t size) +{ + png_uint_32 u0 = seed[0], u1 = seed[1]; + png_bytep bytes = voidcast(png_bytep, pv); + + /* There are thirty three bits, the next bit in the sequence is bit-33 XOR + * bit-20. The top 1 bit is in u1, the bottom 32 are in u0. + */ + size_t i; + for (i=0; i<size; ++i) + { + /* First generate 8 new bits then shift them in at the end. */ + png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; + u1 <<= 8; + u1 |= u0 >> 24; + u0 <<= 8; + u0 |= u; + *bytes++ = (png_byte)u; + } + + seed[0] = u0; + seed[1] = u1; +} + +static void +random_color(png_colorp color) +{ + static png_uint_32 color_seed[2] = { 0x12345678, 0x9abcdef }; + make_random_bytes(color_seed, color, sizeof *color); +} + +/* Math support - neither Cygwin nor Visual Studio have C99 support and we need + * a predictable rounding function, so make one here: + */ +static double +closestinteger(double x) +{ + return floor(x + .5); +} + +/* Cast support: remove GCC whines. */ +static png_byte +u8d(double d) +{ + d = closestinteger(d); + return (png_byte)d; +} + +static png_uint_16 +u16d(double d) +{ + d = closestinteger(d); + return (png_uint_16)d; +} + +/* sRGB support: use exact calculations rounded to the nearest int, see the + * fesetround() call in main(). sRGB_to_d optimizes the 8 to 16-bit conversion. + */ +static double sRGB_to_d[256]; +static double g22_to_d[256]; + +static void +init_sRGB_to_d(void) +{ + int i; + + sRGB_to_d[0] = 0; + for (i=1; i<255; ++i) + sRGB_to_d[i] = linear_from_sRGB(i/255.); + sRGB_to_d[255] = 1; + + g22_to_d[0] = 0; + for (i=1; i<255; ++i) + g22_to_d[i] = pow(i/255., 1/.45455); + g22_to_d[255] = 1; +} + +static png_byte +sRGB(double linear /*range 0.0 .. 1.0*/) +{ + return u8d(255 * sRGB_from_linear(linear)); +} + +static png_byte +isRGB(int fixed_linear) +{ + return sRGB(fixed_linear / 65535.); +} + +#if 0 /* not used */ +static png_byte +unpremultiply(int component, int alpha) +{ + if (alpha <= component) + return 255; /* Arbitrary, but consistent with the libpng code */ + + else if (alpha >= 65535) + return isRGB(component); + + else + return sRGB((double)component / alpha); +} +#endif + +static png_uint_16 +ilinear(int fixed_srgb) +{ + return u16d(65535 * sRGB_to_d[fixed_srgb]); +} + +static png_uint_16 +ilineara(int fixed_srgb, int alpha) +{ + return u16d((257 * alpha) * sRGB_to_d[fixed_srgb]); +} + +static png_uint_16 +ilinear_g22(int fixed_srgb) +{ + return u16d(65535 * g22_to_d[fixed_srgb]); +} + +#if ALLOW_UNUSED_GPC +static png_uint_16 +ilineara_g22(int fixed_srgb, int alpha) +{ + return u16d((257 * alpha) * g22_to_d[fixed_srgb]); +} +#endif + +static double +YfromRGBint(int ir, int ig, int ib) +{ + double r = ir; + double g = ig; + double b = ib; + return YfromRGB(r, g, b); +} + +#if 0 /* unused */ +/* The error that results from using a 2.2 power law in place of the correct + * sRGB transform, given an 8-bit value which might be either sRGB or power-law. + */ +static int +power_law_error8(int value) +{ + if (value > 0 && value < 255) + { + double vd = value / 255.; + double e = fabs( + pow(sRGB_to_d[value], 1/2.2) - sRGB_from_linear(pow(vd, 2.2))); + + /* Always allow an extra 1 here for rounding errors */ + e = 1+floor(255 * e); + return (int)e; + } + + return 0; +} + +static int error_in_sRGB_roundtrip = 56; /* by experiment */ +static int +power_law_error16(int value) +{ + if (value > 0 && value < 65535) + { + /* Round trip the value through an 8-bit representation but using + * non-matching to/from conversions. + */ + double vd = value / 65535.; + double e = fabs( + pow(sRGB_from_linear(vd), 2.2) - linear_from_sRGB(pow(vd, 1/2.2))); + + /* Always allow an extra 1 here for rounding errors */ + e = error_in_sRGB_roundtrip+floor(65535 * e); + return (int)e; + } + + return 0; +} + +static int +compare_8bit(int v1, int v2, int error_limit, int multiple_algorithms) +{ + int e = abs(v1-v2); + int ev1, ev2; + + if (e <= error_limit) + return 1; + + if (!multiple_algorithms) + return 0; + + ev1 = power_law_error8(v1); + if (e <= ev1) + return 1; + + ev2 = power_law_error8(v2); + if (e <= ev2) + return 1; + + return 0; +} + +static int +compare_16bit(int v1, int v2, int error_limit, int multiple_algorithms) +{ + int e = abs(v1-v2); + int ev1, ev2; + + if (e <= error_limit) + return 1; + + /* "multiple_algorithms" in this case means that a color-map has been + * involved somewhere, so we can deduce that the values were forced to 8-bit + * (like the via_linear case for 8-bit.) + */ + if (!multiple_algorithms) + return 0; + + ev1 = power_law_error16(v1); + if (e <= ev1) + return 1; + + ev2 = power_law_error16(v2); + if (e <= ev2) + return 1; + + return 0; +} +#endif /* unused */ + +#define READ_FILE 1 /* else memory */ +#define USE_STDIO 2 /* else use file name */ +#define STRICT 4 /* fail on warnings too */ +#define VERBOSE 8 +#define KEEP_TMPFILES 16 /* else delete temporary files */ +#define KEEP_GOING 32 +#define ACCUMULATE 64 +#define FAST_WRITE 128 +#define sRGB_16BIT 256 + +static void +print_opts(png_uint_32 opts) +{ + if (opts & READ_FILE) + printf(" --file"); + if (opts & USE_STDIO) + printf(" --stdio"); + if (opts & STRICT) + printf(" --strict"); + if (opts & VERBOSE) + printf(" --verbose"); + if (opts & KEEP_TMPFILES) + printf(" --preserve"); + if (opts & KEEP_GOING) + printf(" --keep-going"); + if (opts & ACCUMULATE) + printf(" --accumulate"); + if (!(opts & FAST_WRITE)) /* --fast is currently the default */ + printf(" --slow"); + if (opts & sRGB_16BIT) + printf(" --sRGB-16bit"); +} + +#define FORMAT_NO_CHANGE 0x80000000 /* additional flag */ + +/* A name table for all the formats - defines the format of the '+' arguments to + * pngstest. + */ +#define FORMAT_COUNT 64 +#define FORMAT_MASK 0x3f +static PNG_CONST char * PNG_CONST format_names[FORMAT_COUNT] = +{ + "sRGB-gray", + "sRGB-gray+alpha", + "sRGB-rgb", + "sRGB-rgb+alpha", + "linear-gray", + "linear-gray+alpha", + "linear-rgb", + "linear-rgb+alpha", + + "color-mapped-sRGB-gray", + "color-mapped-sRGB-gray+alpha", + "color-mapped-sRGB-rgb", + "color-mapped-sRGB-rgb+alpha", + "color-mapped-linear-gray", + "color-mapped-linear-gray+alpha", + "color-mapped-linear-rgb", + "color-mapped-linear-rgb+alpha", + + "sRGB-gray", + "sRGB-gray+alpha", + "sRGB-bgr", + "sRGB-bgr+alpha", + "linear-gray", + "linear-gray+alpha", + "linear-bgr", + "linear-bgr+alpha", + + "color-mapped-sRGB-gray", + "color-mapped-sRGB-gray+alpha", + "color-mapped-sRGB-bgr", + "color-mapped-sRGB-bgr+alpha", + "color-mapped-linear-gray", + "color-mapped-linear-gray+alpha", + "color-mapped-linear-bgr", + "color-mapped-linear-bgr+alpha", + + "sRGB-gray", + "alpha+sRGB-gray", + "sRGB-rgb", + "alpha+sRGB-rgb", + "linear-gray", + "alpha+linear-gray", + "linear-rgb", + "alpha+linear-rgb", + + "color-mapped-sRGB-gray", + "color-mapped-alpha+sRGB-gray", + "color-mapped-sRGB-rgb", + "color-mapped-alpha+sRGB-rgb", + "color-mapped-linear-gray", + "color-mapped-alpha+linear-gray", + "color-mapped-linear-rgb", + "color-mapped-alpha+linear-rgb", + + "sRGB-gray", + "alpha+sRGB-gray", + "sRGB-bgr", + "alpha+sRGB-bgr", + "linear-gray", + "alpha+linear-gray", + "linear-bgr", + "alpha+linear-bgr", + + "color-mapped-sRGB-gray", + "color-mapped-alpha+sRGB-gray", + "color-mapped-sRGB-bgr", + "color-mapped-alpha+sRGB-bgr", + "color-mapped-linear-gray", + "color-mapped-alpha+linear-gray", + "color-mapped-linear-bgr", + "color-mapped-alpha+linear-bgr", +}; + +/* Decode an argument to a format number. */ +static png_uint_32 +formatof(const char *arg) +{ + char *ep; + unsigned long format = strtoul(arg, &ep, 0); + + if (ep > arg && *ep == 0 && format < FORMAT_COUNT) + return (png_uint_32)format; + + else for (format=0; format < FORMAT_COUNT; ++format) + { + if (strcmp(format_names[format], arg) == 0) + return (png_uint_32)format; + } + + fprintf(stderr, "pngstest: format name '%s' invalid\n", arg); + return FORMAT_COUNT; +} + +/* Bitset/test functions for formats */ +#define FORMAT_SET_COUNT (FORMAT_COUNT / 32) +typedef struct +{ + png_uint_32 bits[FORMAT_SET_COUNT]; +} +format_list; + +static void format_init(format_list *pf) +{ + int i; + for (i=0; i<FORMAT_SET_COUNT; ++i) + pf->bits[i] = 0; /* All off */ +} + +#if 0 /* currently unused */ +static void format_clear(format_list *pf) +{ + int i; + for (i=0; i<FORMAT_SET_COUNT; ++i) + pf->bits[i] = 0; +} +#endif + +static int format_is_initial(format_list *pf) +{ + int i; + for (i=0; i<FORMAT_SET_COUNT; ++i) + if (pf->bits[i] != 0) + return 0; + + return 1; +} + +static int format_set(format_list *pf, png_uint_32 format) +{ + if (format < FORMAT_COUNT) + return pf->bits[format >> 5] |= ((png_uint_32)1) << (format & 31); + + return 0; +} + +#if 0 /* currently unused */ +static int format_unset(format_list *pf, png_uint_32 format) +{ + if (format < FORMAT_COUNT) + return pf->bits[format >> 5] &= ~((png_uint_32)1) << (format & 31); + + return 0; +} +#endif + +static int format_isset(format_list *pf, png_uint_32 format) +{ + return format < FORMAT_COUNT && + (pf->bits[format >> 5] & (((png_uint_32)1) << (format & 31))) != 0; +} + +static void format_default(format_list *pf, int redundant) +{ + if (redundant) + { + int i; + + /* set everything, including flags that are pointless */ + for (i=0; i<FORMAT_SET_COUNT; ++i) + pf->bits[i] = ~(png_uint_32)0; + } + + else + { + png_uint_32 f; + + for (f=0; f<FORMAT_COUNT; ++f) + { + /* Eliminate redundant and unsupported settings. */ +# ifdef PNG_FORMAT_BGR_SUPPORTED + /* BGR is meaningless if no color: */ + if ((f & PNG_FORMAT_FLAG_COLOR) == 0 && + (f & PNG_FORMAT_FLAG_BGR) != 0) +# else + if ((f & 0x10U/*HACK: fixed value*/) != 0) +# endif + continue; + + /* AFIRST is meaningless if no alpha: */ +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if ((f & PNG_FORMAT_FLAG_ALPHA) == 0 && + (f & PNG_FORMAT_FLAG_AFIRST) != 0) +# else + if ((f & 0x20U/*HACK: fixed value*/) != 0) +# endif + continue; + + format_set(pf, f); + } + } +} + +/* THE Image STRUCTURE */ +/* The super-class of a png_image, contains the decoded image plus the input + * data necessary to re-read the file with a different format. + */ +typedef struct +{ + png_image image; + png_uint_32 opts; + const char *file_name; + int stride_extra; + FILE *input_file; + png_voidp input_memory; + png_size_t input_memory_size; + png_bytep buffer; + ptrdiff_t stride; + png_size_t bufsize; + png_size_t allocsize; + char tmpfile_name[32]; + png_uint_16 colormap[256*4]; +} +Image; + +/* Initializer: also sets the permitted error limit for 16-bit operations. */ +static void +newimage(Image *image) +{ + memset(image, 0, sizeof *image); +} + +/* Reset the image to be read again - only needs to rewind the FILE* at present. + */ +static void +resetimage(Image *image) +{ + if (image->input_file != NULL) + rewind(image->input_file); +} + +/* Free the image buffer; the buffer is re-used on a re-read, this is just for + * cleanup. + */ +static void +freebuffer(Image *image) +{ + if (image->buffer) free(image->buffer); + image->buffer = NULL; + image->bufsize = 0; + image->allocsize = 0; +} + +/* Delete function; cleans out all the allocated data and the temporary file in + * the image. + */ +static void +freeimage(Image *image) +{ + freebuffer(image); + png_image_free(&image->image); + + if (image->input_file != NULL) + { + fclose(image->input_file); + image->input_file = NULL; + } + + if (image->input_memory != NULL) + { + free(image->input_memory); + image->input_memory = NULL; + image->input_memory_size = 0; + } + + if (image->tmpfile_name[0] != 0 && (image->opts & KEEP_TMPFILES) == 0) + { + remove(image->tmpfile_name); + image->tmpfile_name[0] = 0; + } +} + +/* This is actually a re-initializer; allows an image structure to be re-used by + * freeing everything that relates to an old image. + */ +static void initimage(Image *image, png_uint_32 opts, const char *file_name, + int stride_extra) +{ + freeimage(image); + memset(&image->image, 0, sizeof image->image); + image->opts = opts; + image->file_name = file_name; + image->stride_extra = stride_extra; +} + +/* Make sure the image buffer is big enough; allows re-use of the buffer if the + * image is re-read. + */ +#define BUFFER_INIT8 73 +static void +allocbuffer(Image *image) +{ + png_size_t size = PNG_IMAGE_BUFFER_SIZE(image->image, image->stride); + + if (size+32 > image->bufsize) + { + freebuffer(image); + image->buffer = voidcast(png_bytep, malloc(size+32)); + if (image->buffer == NULL) + { + fflush(stdout); + fprintf(stderr, + "simpletest: out of memory allocating %lu(+32) byte buffer\n", + (unsigned long)size); + exit(1); + } + image->bufsize = size+32; + } + + memset(image->buffer, 95, image->bufsize); + memset(image->buffer+16, BUFFER_INIT8, size); + image->allocsize = size; +} + +/* Make sure 16 bytes match the given byte. */ +static int +check16(png_const_bytep bp, int b) +{ + int i = 16; + + do + if (*bp != b) return 1; + while (--i); + + return 0; +} + +/* Check for overwrite in the image buffer. */ +static void +checkbuffer(Image *image, const char *arg) +{ + if (check16(image->buffer, 95)) + { + fflush(stdout); + fprintf(stderr, "%s: overwrite at start of image buffer\n", arg); + exit(1); + } + + if (check16(image->buffer+16+image->allocsize, 95)) + { + fflush(stdout); + fprintf(stderr, "%s: overwrite at end of image buffer\n", arg); + exit(1); + } +} + +/* ERROR HANDLING */ +/* Log a terminal error, also frees the libpng part of the image if necessary. + */ +static int +logerror(Image *image, const char *a1, const char *a2, const char *a3) +{ + fflush(stdout); + if (image->image.warning_or_error) + fprintf(stderr, "%s%s%s: %s\n", a1, a2, a3, image->image.message); + + else + fprintf(stderr, "%s%s%s\n", a1, a2, a3); + + if (image->image.opaque != NULL) + { + fprintf(stderr, "%s: image opaque pointer non-NULL on error\n", + image->file_name); + png_image_free(&image->image); + } + + return 0; +} + +/* Log an error and close a file (just a utility to do both things in one + * function call.) + */ +static int +logclose(Image *image, FILE *f, const char *name, const char *operation) +{ + int e = errno; + + fclose(f); + return logerror(image, name, operation, strerror(e)); +} + +/* Make sure the png_image has been freed - validates that libpng is doing what + * the spec says and freeing the image. + */ +static int +checkopaque(Image *image) +{ + if (image->image.opaque != NULL) + { + png_image_free(&image->image); + return logerror(image, image->file_name, ": opaque not NULL", ""); + } + + else if (image->image.warning_or_error != 0 && (image->opts & STRICT) != 0) + return logerror(image, image->file_name, " --strict", ""); + + else + return 1; +} + +/* IMAGE COMPARISON/CHECKING */ +/* Compare the pixels of two images, which should be the same but aren't. The + * images must have been checked for a size match. + */ +typedef struct +{ + /* The components, for grayscale images the gray value is in 'g' and if alpha + * is not present 'a' is set to 255 or 65535 according to format. + */ + int r, g, b, a; +} Pixel; + +typedef struct +{ + /* The background as the original sRGB 8-bit value converted to the final + * integer format and as a double precision linear value in the range 0..1 + * for with partially transparent pixels. + */ + int ir, ig, ib; + double dr, dg, db; /* linear r,g,b scaled to 0..1 */ +} Background; + +/* Basic image formats; control the data but not the layout thereof. */ +#define BASE_FORMATS\ + (PNG_FORMAT_FLAG_ALPHA|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_LINEAR) + +/* Read a Pixel from a buffer. The code below stores the correct routine for + * the format in a function pointer, these are the routines: + */ +static void +gp_g8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = p->g = p->b = pp[0]; + p->a = 255; +} + +static void +gp_ga8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = p->g = p->b = pp[0]; + p->a = pp[1]; +} + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED +static void +gp_ag8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = p->g = p->b = pp[1]; + p->a = pp[0]; +} +#endif + +static void +gp_rgb8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = pp[0]; + p->g = pp[1]; + p->b = pp[2]; + p->a = 255; +} + +#ifdef PNG_FORMAT_BGR_SUPPORTED +static void +gp_bgr8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = pp[2]; + p->g = pp[1]; + p->b = pp[0]; + p->a = 255; +} +#endif + +static void +gp_rgba8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = pp[0]; + p->g = pp[1]; + p->b = pp[2]; + p->a = pp[3]; +} + +#ifdef PNG_FORMAT_BGR_SUPPORTED +static void +gp_bgra8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = pp[2]; + p->g = pp[1]; + p->b = pp[0]; + p->a = pp[3]; +} +#endif + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED +static void +gp_argb8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = pp[1]; + p->g = pp[2]; + p->b = pp[3]; + p->a = pp[0]; +} +#endif + +#if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED) +static void +gp_abgr8(Pixel *p, png_const_voidp pb) +{ + png_const_bytep pp = voidcast(png_const_bytep, pb); + + p->r = pp[3]; + p->g = pp[2]; + p->b = pp[1]; + p->a = pp[0]; +} +#endif + +static void +gp_g16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = p->g = p->b = pp[0]; + p->a = 65535; +} + +static void +gp_ga16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = p->g = p->b = pp[0]; + p->a = pp[1]; +} + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED +static void +gp_ag16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = p->g = p->b = pp[1]; + p->a = pp[0]; +} +#endif + +static void +gp_rgb16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = pp[0]; + p->g = pp[1]; + p->b = pp[2]; + p->a = 65535; +} + +#ifdef PNG_FORMAT_BGR_SUPPORTED +static void +gp_bgr16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = pp[2]; + p->g = pp[1]; + p->b = pp[0]; + p->a = 65535; +} +#endif + +static void +gp_rgba16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = pp[0]; + p->g = pp[1]; + p->b = pp[2]; + p->a = pp[3]; +} + +#ifdef PNG_FORMAT_BGR_SUPPORTED +static void +gp_bgra16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = pp[2]; + p->g = pp[1]; + p->b = pp[0]; + p->a = pp[3]; +} +#endif + +#ifdef PNG_FORMAT_AFIRST_SUPPORTED +static void +gp_argb16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = pp[1]; + p->g = pp[2]; + p->b = pp[3]; + p->a = pp[0]; +} +#endif + +#if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED) +static void +gp_abgr16(Pixel *p, png_const_voidp pb) +{ + png_const_uint_16p pp = voidcast(png_const_uint_16p, pb); + + p->r = pp[3]; + p->g = pp[2]; + p->b = pp[1]; + p->a = pp[0]; +} +#endif + +/* Given a format, return the correct one of the above functions. */ +static void (* +get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb) +{ + /* The color-map flag is irrelevant here - the caller of the function + * returned must either pass the buffer or, for a color-mapped image, the + * correct entry in the color-map. + */ + if (format & PNG_FORMAT_FLAG_LINEAR) + { + if (format & PNG_FORMAT_FLAG_COLOR) + { +# ifdef PNG_FORMAT_BGR_SUPPORTED + if (format & PNG_FORMAT_FLAG_BGR) + { + if (format & PNG_FORMAT_FLAG_ALPHA) + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (format & PNG_FORMAT_FLAG_AFIRST) + return gp_abgr16; + + else +# endif + return gp_bgra16; + } + + else + return gp_bgr16; + } + + else +# endif + { + if (format & PNG_FORMAT_FLAG_ALPHA) + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (format & PNG_FORMAT_FLAG_AFIRST) + return gp_argb16; + + else +# endif + return gp_rgba16; + } + + else + return gp_rgb16; + } + } + + else + { + if (format & PNG_FORMAT_FLAG_ALPHA) + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (format & PNG_FORMAT_FLAG_AFIRST) + return gp_ag16; + + else +# endif + return gp_ga16; + } + + else + return gp_g16; + } + } + + else + { + if (format & PNG_FORMAT_FLAG_COLOR) + { +# ifdef PNG_FORMAT_BGR_SUPPORTED + if (format & PNG_FORMAT_FLAG_BGR) + { + if (format & PNG_FORMAT_FLAG_ALPHA) + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (format & PNG_FORMAT_FLAG_AFIRST) + return gp_abgr8; + + else +# endif + return gp_bgra8; + } + + else + return gp_bgr8; + } + + else +# endif + { + if (format & PNG_FORMAT_FLAG_ALPHA) + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (format & PNG_FORMAT_FLAG_AFIRST) + return gp_argb8; + + else +# endif + return gp_rgba8; + } + + else + return gp_rgb8; + } + } + + else + { + if (format & PNG_FORMAT_FLAG_ALPHA) + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (format & PNG_FORMAT_FLAG_AFIRST) + return gp_ag8; + + else +# endif + return gp_ga8; + } + + else + return gp_g8; + } + } +} + +/* Convertion between pixel formats. The code above effectively eliminates the + * component ordering changes leaving three basic changes: + * + * 1) Remove an alpha channel by pre-multiplication or compositing on a + * background color. (Adding an alpha channel is a no-op.) + * + * 2) Remove color by mapping to grayscale. (Grayscale to color is a no-op.) + * + * 3) Convert between 8-bit and 16-bit components. (Both directtions are + * relevant.) + * + * This gives the following base format conversion matrix: + * + * OUT: ----- 8-bit ----- ----- 16-bit ----- + * IN G GA RGB RGBA G GA RGB RGBA + * 8 G . . . . lin lin lin lin + * 8 GA bckg . bckc . pre' pre pre' pre + * 8 RGB g8 g8 . . glin glin lin lin + * 8 RGBA g8b g8 bckc . gpr' gpre pre' pre + * 16 G sRGB sRGB sRGB sRGB . . . . + * 16 GA b16g unpg b16c unpc A . A . + * 16 RGB sG sG sRGB sRGB g16 g16 . . + * 16 RGBA gb16 sGp cb16 sCp g16 g16' A . + * + * 8-bit to 8-bit: + * bckg: composite on gray background + * bckc: composite on color background + * g8: convert sRGB components to sRGB grayscale + * g8b: convert sRGB components to grayscale and composite on gray background + * + * 8-bit to 16-bit: + * lin: make sRGB components linear, alpha := 65535 + * pre: make sRGB components linear and premultiply by alpha (scale alpha) + * pre': as 'pre' but alpha := 65535 + * glin: make sRGB components linear, convert to grayscale, alpha := 65535 + * gpre: make sRGB components grayscale and linear and premultiply by alpha + * gpr': as 'gpre' but alpha := 65535 + * + * 16-bit to 8-bit: + * sRGB: convert linear components to sRGB, alpha := 255 + * unpg: unpremultiply gray component and convert to sRGB (scale alpha) + * unpc: unpremultiply color components and convert to sRGB (scale alpha) + * b16g: composite linear onto gray background and convert the result to sRGB + * b16c: composite linear onto color background and convert the result to sRGB + * sG: convert linear RGB to sRGB grayscale + * sGp: unpremultiply RGB then convert to sRGB grayscale + * sCp: unpremultiply RGB then convert to sRGB + * gb16: composite linear onto background and convert to sRGB grayscale + * (order doesn't matter, the composite and grayscale operations permute) + * cb16: composite linear onto background and convert to sRGB + * + * 16-bit to 16-bit: + * A: set alpha to 65535 + * g16: convert linear RGB to linear grayscale (alpha := 65535) + * g16': as 'g16' but alpha is unchanged + */ +/* Simple copy: */ +static void +gpc_noop(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + out->r = in->r; + out->g = in->g; + out->b = in->b; + out->a = in->a; +} + +#if ALLOW_UNUSED_GPC +static void +gpc_nop8(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + if (in->a == 0) + out->r = out->g = out->b = 255; + + else + { + out->r = in->r; + out->g = in->g; + out->b = in->b; + } + + out->a = in->a; +} +#endif + +#if ALLOW_UNUSED_GPC +static void +gpc_nop6(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + if (in->a == 0) + out->r = out->g = out->b = 65535; + + else + { + out->r = in->r; + out->g = in->g; + out->b = in->b; + } + + out->a = in->a; +} +#endif + +/* 8-bit to 8-bit conversions */ +/* bckg: composite on gray background */ +static void +gpc_bckg(Pixel *out, const Pixel *in, const Background *back) +{ + if (in->a <= 0) + out->r = out->g = out->b = back->ig; + + else if (in->a >= 255) + out->r = out->g = out->b = in->g; + + else + { + double a = in->a / 255.; + + out->r = out->g = out->b = sRGB(sRGB_to_d[in->g] * a + back->dg * (1-a)); + } + + out->a = 255; +} + +/* bckc: composite on color background */ +static void +gpc_bckc(Pixel *out, const Pixel *in, const Background *back) +{ + if (in->a <= 0) + { + out->r = back->ir; + out->g = back->ig; + out->b = back->ib; + } + + else if (in->a >= 255) + { + out->r = in->r; + out->g = in->g; + out->b = in->b; + } + + else + { + double a = in->a / 255.; + + out->r = sRGB(sRGB_to_d[in->r] * a + back->dr * (1-a)); + out->g = sRGB(sRGB_to_d[in->g] * a + back->dg * (1-a)); + out->b = sRGB(sRGB_to_d[in->b] * a + back->db * (1-a)); + } + + out->a = 255; +} + +/* g8: convert sRGB components to sRGB grayscale */ +static void +gpc_g8(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = in->g; + + else + out->r = out->g = out->b = + sRGB(YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); + + out->a = in->a; +} + +/* g8b: convert sRGB components to grayscale and composite on gray background */ +static void +gpc_g8b(Pixel *out, const Pixel *in, const Background *back) +{ + if (in->a <= 0) + out->r = out->g = out->b = back->ig; + + else if (in->a >= 255) + { + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = in->g; + + else + out->r = out->g = out->b = sRGB(YfromRGB( + sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); + } + + else + { + double a = in->a/255.; + + out->r = out->g = out->b = sRGB(a * YfromRGB(sRGB_to_d[in->r], + sRGB_to_d[in->g], sRGB_to_d[in->b]) + back->dg * (1-a)); + } + + out->a = 255; +} + +/* 8-bit to 16-bit conversions */ +/* lin: make sRGB components linear, alpha := 65535 */ +static void +gpc_lin(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = ilinear(in->r); + + if (in->g == in->r) + { + out->g = out->r; + + if (in->b == in->r) + out->b = out->r; + + else + out->b = ilinear(in->b); + } + + else + { + out->g = ilinear(in->g); + + if (in->b == in->r) + out->b = out->r; + + else if (in->b == in->g) + out->b = out->g; + + else + out->b = ilinear(in->b); + } + + out->a = 65535; +} + +/* pre: make sRGB components linear and premultiply by alpha (scale alpha) */ +static void +gpc_pre(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = ilineara(in->r, in->a); + + if (in->g == in->r) + { + out->g = out->r; + + if (in->b == in->r) + out->b = out->r; + + else + out->b = ilineara(in->b, in->a); + } + + else + { + out->g = ilineara(in->g, in->a); + + if (in->b == in->r) + out->b = out->r; + + else if (in->b == in->g) + out->b = out->g; + + else + out->b = ilineara(in->b, in->a); + } + + out->a = in->a * 257; +} + +/* pre': as 'pre' but alpha := 65535 */ +static void +gpc_preq(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = ilineara(in->r, in->a); + + if (in->g == in->r) + { + out->g = out->r; + + if (in->b == in->r) + out->b = out->r; + + else + out->b = ilineara(in->b, in->a); + } + + else + { + out->g = ilineara(in->g, in->a); + + if (in->b == in->r) + out->b = out->r; + + else if (in->b == in->g) + out->b = out->g; + + else + out->b = ilineara(in->b, in->a); + } + + out->a = 65535; +} + +/* glin: make sRGB components linear, convert to grayscale, alpha := 65535 */ +static void +gpc_glin(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = ilinear(in->g); + + else + out->r = out->g = out->b = u16d(65535 * + YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); + + out->a = 65535; +} + +/* gpre: make sRGB components grayscale and linear and premultiply by alpha */ +static void +gpc_gpre(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = ilineara(in->g, in->a); + + else + out->r = out->g = out->b = u16d(in->a * 257 * + YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); + + out->a = 257 * in->a; +} + +/* gpr': as 'gpre' but alpha := 65535 */ +static void +gpc_gprq(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = ilineara(in->g, in->a); + + else + out->r = out->g = out->b = u16d(in->a * 257 * + YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); + + out->a = 65535; +} + +/* 8-bit to 16-bit conversions for gAMA 45455 encoded values */ +/* Lin: make gAMA 45455 components linear, alpha := 65535 */ +static void +gpc_Lin(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = ilinear_g22(in->r); + + if (in->g == in->r) + { + out->g = out->r; + + if (in->b == in->r) + out->b = out->r; + + else + out->b = ilinear_g22(in->b); + } + + else + { + out->g = ilinear_g22(in->g); + + if (in->b == in->r) + out->b = out->r; + + else if (in->b == in->g) + out->b = out->g; + + else + out->b = ilinear_g22(in->b); + } + + out->a = 65535; +} + +#if ALLOW_UNUSED_GPC +/* Pre: make gAMA 45455 components linear and premultiply by alpha (scale alpha) + */ +static void +gpc_Pre(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = ilineara_g22(in->r, in->a); + + if (in->g == in->r) + { + out->g = out->r; + + if (in->b == in->r) + out->b = out->r; + + else + out->b = ilineara_g22(in->b, in->a); + } + + else + { + out->g = ilineara_g22(in->g, in->a); + + if (in->b == in->r) + out->b = out->r; + + else if (in->b == in->g) + out->b = out->g; + + else + out->b = ilineara_g22(in->b, in->a); + } + + out->a = in->a * 257; +} +#endif + +#if ALLOW_UNUSED_GPC +/* Pre': as 'Pre' but alpha := 65535 */ +static void +gpc_Preq(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = ilineara_g22(in->r, in->a); + + if (in->g == in->r) + { + out->g = out->r; + + if (in->b == in->r) + out->b = out->r; + + else + out->b = ilineara_g22(in->b, in->a); + } + + else + { + out->g = ilineara_g22(in->g, in->a); + + if (in->b == in->r) + out->b = out->r; + + else if (in->b == in->g) + out->b = out->g; + + else + out->b = ilineara_g22(in->b, in->a); + } + + out->a = 65535; +} +#endif + +#if ALLOW_UNUSED_GPC +/* Glin: make gAMA 45455 components linear, convert to grayscale, alpha := 65535 + */ +static void +gpc_Glin(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = ilinear_g22(in->g); + + else + out->r = out->g = out->b = u16d(65535 * + YfromRGB(g22_to_d[in->r], g22_to_d[in->g], g22_to_d[in->b])); + + out->a = 65535; +} +#endif + +#if ALLOW_UNUSED_GPC +/* Gpre: make gAMA 45455 components grayscale and linear and premultiply by + * alpha. + */ +static void +gpc_Gpre(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = ilineara_g22(in->g, in->a); + + else + out->r = out->g = out->b = u16d(in->a * 257 * + YfromRGB(g22_to_d[in->r], g22_to_d[in->g], g22_to_d[in->b])); + + out->a = 257 * in->a; +} +#endif + +#if ALLOW_UNUSED_GPC +/* Gpr': as 'Gpre' but alpha := 65535 */ +static void +gpc_Gprq(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->r == in->g && in->g == in->b) + out->r = out->g = out->b = ilineara_g22(in->g, in->a); + + else + out->r = out->g = out->b = u16d(in->a * 257 * + YfromRGB(g22_to_d[in->r], g22_to_d[in->g], g22_to_d[in->b])); + + out->a = 65535; +} +#endif + +/* 16-bit to 8-bit conversions */ +/* sRGB: convert linear components to sRGB, alpha := 255 */ +static void +gpc_sRGB(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = isRGB(in->r); + + if (in->g == in->r) + { + out->g = out->r; + + if (in->b == in->r) + out->b = out->r; + + else + out->b = isRGB(in->b); + } + + else + { + out->g = isRGB(in->g); + + if (in->b == in->r) + out->b = out->r; + + else if (in->b == in->g) + out->b = out->g; + + else + out->b = isRGB(in->b); + } + + out->a = 255; +} + +/* unpg: unpremultiply gray component and convert to sRGB (scale alpha) */ +static void +gpc_unpg(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->a <= 128) + { + out->r = out->g = out->b = 255; + out->a = 0; + } + + else + { + out->r = out->g = out->b = sRGB((double)in->g / in->a); + out->a = u8d(in->a / 257.); + } +} + +/* unpc: unpremultiply color components and convert to sRGB (scale alpha) */ +static void +gpc_unpc(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->a <= 128) + { + out->r = out->g = out->b = 255; + out->a = 0; + } + + else + { + out->r = sRGB((double)in->r / in->a); + out->g = sRGB((double)in->g / in->a); + out->b = sRGB((double)in->b / in->a); + out->a = u8d(in->a / 257.); + } +} + +/* b16g: composite linear onto gray background and convert the result to sRGB */ +static void +gpc_b16g(Pixel *out, const Pixel *in, const Background *back) +{ + if (in->a <= 0) + out->r = out->g = out->b = back->ig; + + else + { + double a = in->a/65535.; + double a1 = 1-a; + + a /= 65535; + out->r = out->g = out->b = sRGB(in->g * a + back->dg * a1); + } + + out->a = 255; +} + +/* b16c: composite linear onto color background and convert the result to sRGB*/ +static void +gpc_b16c(Pixel *out, const Pixel *in, const Background *back) +{ + if (in->a <= 0) + { + out->r = back->ir; + out->g = back->ig; + out->b = back->ib; + } + + else + { + double a = in->a/65535.; + double a1 = 1-a; + + a /= 65535; + out->r = sRGB(in->r * a + back->dr * a1); + out->g = sRGB(in->g * a + back->dg * a1); + out->b = sRGB(in->b * a + back->db * a1); + } + + out->a = 255; +} + +/* sG: convert linear RGB to sRGB grayscale */ +static void +gpc_sG(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + out->r = out->g = out->b = sRGB(YfromRGBint(in->r, in->g, in->b)/65535); + out->a = 255; +} + +/* sGp: unpremultiply RGB then convert to sRGB grayscale */ +static void +gpc_sGp(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->a <= 128) + { + out->r = out->g = out->b = 255; + out->a = 0; + } + + else + { + out->r = out->g = out->b = sRGB(YfromRGBint(in->r, in->g, in->b)/in->a); + out->a = u8d(in->a / 257.); + } +} + +/* sCp: unpremultiply RGB then convert to sRGB */ +static void +gpc_sCp(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + + if (in->a <= 128) + { + out->r = out->g = out->b = 255; + out->a = 0; + } + + else + { + out->r = sRGB((double)in->r / in->a); + out->g = sRGB((double)in->g / in->a); + out->b = sRGB((double)in->b / in->a); + out->a = u8d(in->a / 257.); + } +} + +/* gb16: composite linear onto background and convert to sRGB grayscale */ +/* (order doesn't matter, the composite and grayscale operations permute) */ +static void +gpc_gb16(Pixel *out, const Pixel *in, const Background *back) +{ + if (in->a <= 0) + out->r = out->g = out->b = back->ig; + + else if (in->a >= 65535) + out->r = out->g = out->b = isRGB(in->g); + + else + { + double a = in->a / 65535.; + double a1 = 1-a; + + a /= 65535; + out->r = out->g = out->b = sRGB(in->g * a + back->dg * a1); + } + + out->a = 255; +} + +/* cb16: composite linear onto background and convert to sRGB */ +static void +gpc_cb16(Pixel *out, const Pixel *in, const Background *back) +{ + if (in->a <= 0) + { + out->r = back->ir; + out->g = back->ig; + out->b = back->ib; + } + + else if (in->a >= 65535) + { + out->r = isRGB(in->r); + out->g = isRGB(in->g); + out->b = isRGB(in->b); + } + + else + { + double a = in->a / 65535.; + double a1 = 1-a; + + a /= 65535; + out->r = sRGB(in->r * a + back->dr * a1); + out->g = sRGB(in->g * a + back->dg * a1); + out->b = sRGB(in->b * a + back->db * a1); + } + + out->a = 255; +} + +/* 16-bit to 16-bit conversions */ +/* A: set alpha to 65535 */ +static void +gpc_A(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + out->r = in->r; + out->g = in->g; + out->b = in->b; + out->a = 65535; +} + +/* g16: convert linear RGB to linear grayscale (alpha := 65535) */ +static void +gpc_g16(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + out->r = out->g = out->b = u16d(YfromRGBint(in->r, in->g, in->b)); + out->a = 65535; +} + +/* g16': as 'g16' but alpha is unchanged */ +static void +gpc_g16q(Pixel *out, const Pixel *in, const Background *back) +{ + (void)back; + out->r = out->g = out->b = u16d(YfromRGBint(in->r, in->g, in->b)); + out->a = in->a; +} + +#if ALLOW_UNUSED_GPC +/* Unused functions (to hide them from GCC unused function warnings) */ +void (* const gpc_unused[]) + (Pixel *out, const Pixel *in, const Background *back) = +{ + gpc_Pre, gpc_Preq, gpc_Glin, gpc_Gpre, gpc_Gprq, gpc_nop8, gpc_nop6 +}; +#endif + +/* OUT: ----- 8-bit ----- ----- 16-bit ----- + * IN G GA RGB RGBA G GA RGB RGBA + * 8 G . . . . lin lin lin lin + * 8 GA bckg . bckc . pre' pre pre' pre + * 8 RGB g8 g8 . . glin glin lin lin + * 8 RGBA g8b g8 bckc . gpr' gpre pre' pre + * 16 G sRGB sRGB sRGB sRGB . . . . + * 16 GA b16g unpg b16c unpc A . A . + * 16 RGB sG sG sRGB sRGB g16 g16 . . + * 16 RGBA gb16 sGp cb16 sCp g16 g16' A . + * + * The matrix is held in an array indexed thus: + * + * gpc_fn[out_format & BASE_FORMATS][in_format & BASE_FORMATS]; + */ +/* This will produce a compile time error if the FORMAT_FLAG values don't + * match the above matrix! + */ +#if PNG_FORMAT_FLAG_ALPHA == 1 && PNG_FORMAT_FLAG_COLOR == 2 &&\ + PNG_FORMAT_FLAG_LINEAR == 4 +static void (* const gpc_fn[8/*in*/][8/*out*/]) + (Pixel *out, const Pixel *in, const Background *back) = +{ +/*out: G-8 GA-8 RGB-8 RGBA-8 G-16 GA-16 RGB-16 RGBA-16 */ + {gpc_noop,gpc_noop,gpc_noop,gpc_noop, gpc_Lin, gpc_Lin, gpc_Lin, gpc_Lin }, + {gpc_bckg,gpc_noop,gpc_bckc,gpc_noop, gpc_preq,gpc_pre, gpc_preq,gpc_pre }, + {gpc_g8, gpc_g8, gpc_noop,gpc_noop, gpc_glin,gpc_glin,gpc_lin, gpc_lin }, + {gpc_g8b, gpc_g8, gpc_bckc,gpc_noop, gpc_gprq,gpc_gpre,gpc_preq,gpc_pre }, + {gpc_sRGB,gpc_sRGB,gpc_sRGB,gpc_sRGB, gpc_noop,gpc_noop,gpc_noop,gpc_noop}, + {gpc_b16g,gpc_unpg,gpc_b16c,gpc_unpc, gpc_A, gpc_noop,gpc_A, gpc_noop}, + {gpc_sG, gpc_sG, gpc_sRGB,gpc_sRGB, gpc_g16, gpc_g16, gpc_noop,gpc_noop}, + {gpc_gb16,gpc_sGp, gpc_cb16,gpc_sCp, gpc_g16, gpc_g16q,gpc_A, gpc_noop} +}; + +/* The array is repeated for the cases where both the input and output are color + * mapped because then different algorithms are used. + */ +static void (* const gpc_fn_colormapped[8/*in*/][8/*out*/]) + (Pixel *out, const Pixel *in, const Background *back) = +{ +/*out: G-8 GA-8 RGB-8 RGBA-8 G-16 GA-16 RGB-16 RGBA-16 */ + {gpc_noop,gpc_noop,gpc_noop,gpc_noop, gpc_lin, gpc_lin, gpc_lin, gpc_lin }, + {gpc_bckg,gpc_noop,gpc_bckc,gpc_noop, gpc_preq,gpc_pre, gpc_preq,gpc_pre }, + {gpc_g8, gpc_g8, gpc_noop,gpc_noop, gpc_glin,gpc_glin,gpc_lin, gpc_lin }, + {gpc_g8b, gpc_g8, gpc_bckc,gpc_noop, gpc_gprq,gpc_gpre,gpc_preq,gpc_pre }, + {gpc_sRGB,gpc_sRGB,gpc_sRGB,gpc_sRGB, gpc_noop,gpc_noop,gpc_noop,gpc_noop}, + {gpc_b16g,gpc_unpg,gpc_b16c,gpc_unpc, gpc_A, gpc_noop,gpc_A, gpc_noop}, + {gpc_sG, gpc_sG, gpc_sRGB,gpc_sRGB, gpc_g16, gpc_g16, gpc_noop,gpc_noop}, + {gpc_gb16,gpc_sGp, gpc_cb16,gpc_sCp, gpc_g16, gpc_g16q,gpc_A, gpc_noop} +}; + +/* The error arrays record the error in the same matrix; 64 entries, however + * the different algorithms used in libpng for colormap and direct conversions + * mean that four separate matrices are used (for each combination of + * colormapped and direct.) + * + * In some cases the conversion between sRGB formats goes via a linear + * intermediate; an sRGB to linear conversion (as above) is followed by a simple + * linear to sRGB step with no other conversions. This is done by a separate + * error array from an arbitrary 'in' format to one of the four basic outputs + * (since final output is always sRGB not colormapped). + * + * These arrays may be modified if the --accumulate flag is set during the run; + * then instead of logging errors they are simply added in. + * + * The three entries are currently for transparent, partially transparent and + * opaque input pixel values. Notice that alpha should be exact in each case. + * + * Errors in alpha should only occur when converting from a direct format + * to a colormapped format, when alpha is effectively smashed (so large + * errors can occur.) There should be no error in the '0' and 'opaque' + * values. The fourth entry in the array is used for the alpha error (and it + * should always be zero for the 'via linear' case since this is never color + * mapped.) + * + * Mapping to a colormap smashes the colors, it is necessary to have separate + * values for these cases because they are much larger; it is very much + * impossible to obtain a reasonable result, these are held in + * gpc_error_to_colormap. + */ +#if PNG_FORMAT_FLAG_COLORMAP == 8 /* extra check also required */ +/* START MACHINE GENERATED */ +static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] = +{ + { /* input: sRGB-gray */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 372, 0 }, { 0, 0, 372, 0 }, { 0, 0, 372, 0 }, { 0, 0, 372, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: sRGB-gray+alpha */ + { 0, 18, 0, 0 }, { 0, 0, 0, 0 }, { 0, 20, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: sRGB-rgb */ + { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 893, 0 }, { 0, 0, 893, 0 }, { 0, 0, 811, 0 }, { 0, 0, 811, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: sRGB-rgb+alpha */ + { 0, 4, 13, 0 }, { 0, 14, 13, 0 }, { 0, 19, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 832, 764, 0 }, { 0, 832, 764, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: linear-gray */ + { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: linear-gray+alpha */ + { 0, 74, 9, 0 }, { 0, 20, 9, 0 }, { 0, 74, 9, 0 }, { 0, 20, 9, 0 }, + { 0, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 0, 0 }, { 0, 1, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: linear-rgb */ + { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, + { 0, 0, 4, 0 }, { 0, 0, 4, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: linear-rgb+alpha */ + { 0, 126, 143, 0 }, { 0, 9, 7, 0 }, { 0, 74, 9, 0 }, { 0, 16, 9, 0 }, + { 0, 4, 4, 0 }, { 0, 5, 4, 0 }, { 0, 0, 0, 0 }, { 0, 1, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-sRGB-gray */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-sRGB-gray+alpha */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-sRGB-rgb */ + { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 8, 0 }, { 0, 0, 8, 0 }, + { 0, 0, 673, 0 }, { 0, 0, 673, 0 }, { 0, 0, 674, 0 }, { 0, 0, 674, 0 }, + { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 460, 0 }, { 0, 0, 460, 0 }, { 0, 0, 263, 0 }, { 0, 0, 263, 0 } + }, { /* input: color-mapped-sRGB-rgb+alpha */ + { 0, 6, 8, 0 }, { 0, 7, 8, 0 }, { 0, 75, 8, 0 }, { 0, 9, 8, 0 }, + { 0, 585, 427, 0 }, { 0, 585, 427, 0 }, { 0, 717, 409, 0 }, { 0, 717, 409, 0 }, + { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 13323, 460, 0 }, { 0, 334, 460, 0 }, { 0, 16480, 263, 0 }, { 0, 243, 263, 0 } + }, { /* input: color-mapped-linear-gray */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 282, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-linear-gray+alpha */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 253, 282, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-linear-rgb */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 265, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-linear-rgb+alpha */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 243, 265, 0 } + } +}; +static png_uint_16 gpc_error_via_linear[16][4/*out*/][4] = +{ + { /* input: sRGB-gray */ + { 0, 0, 7, 0 }, { 0, 0, 7, 0 }, { 0, 0, 7, 0 }, { 0, 0, 7, 0 } + }, { /* input: sRGB-gray+alpha */ + { 0, 15, 15, 0 }, { 0, 186, 15, 0 }, { 0, 15, 15, 0 }, { 0, 186, 15, 0 } + }, { /* input: sRGB-rgb */ + { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 15, 0 }, { 0, 0, 15, 0 } + }, { /* input: sRGB-rgb+alpha */ + { 0, 12, 14, 0 }, { 0, 180, 14, 0 }, { 0, 14, 15, 0 }, { 0, 186, 15, 0 } + }, { /* input: linear-gray */ + { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 } + }, { /* input: linear-gray+alpha */ + { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 } + }, { /* input: linear-rgb */ + { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 } + }, { /* input: linear-rgb+alpha */ + { 0, 1, 1, 0 }, { 0, 8, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 1, 0 } + }, { /* input: color-mapped-sRGB-gray */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-sRGB-gray+alpha */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-sRGB-rgb */ + { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 14, 0 }, { 0, 0, 14, 0 } + }, { /* input: color-mapped-sRGB-rgb+alpha */ + { 0, 4, 8, 0 }, { 0, 9, 8, 0 }, { 0, 8, 3, 0 }, { 0, 32, 3, 0 } + }, { /* input: color-mapped-linear-gray */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-linear-gray+alpha */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-linear-rgb */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + }, { /* input: color-mapped-linear-rgb+alpha */ + { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 } + } +}; +static png_uint_16 gpc_error_to_colormap[8/*i*/][8/*o*/][4] = +{ + { /* input: sRGB-gray */ + { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, + { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 } + }, { /* input: sRGB-gray+alpha */ + { 0, 19, 2, 0 }, { 0, 255, 2, 25 }, { 0, 88, 2, 0 }, { 0, 255, 2, 25 }, + { 0, 1012, 745, 0 }, { 0, 16026, 745, 6425 }, { 0, 1012, 745, 0 }, { 0, 16026, 745, 6425 } + }, { /* input: sRGB-rgb */ + { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 25, 0 }, { 0, 0, 25, 0 }, + { 0, 0, 937, 0 }, { 0, 0, 937, 0 }, { 0, 0, 13677, 0 }, { 0, 0, 13677, 0 } + }, { /* input: sRGB-rgb+alpha */ + { 0, 63, 77, 0 }, { 0, 255, 19, 25 }, { 0, 220, 25, 0 }, { 0, 255, 25, 67 }, + { 0, 17534, 18491, 0 }, { 0, 15614, 2824, 6425 }, { 0, 14019, 13677, 0 }, { 0, 48573, 13677, 17219 } + }, { /* input: linear-gray */ + { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, + { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 } + }, { /* input: linear-gray+alpha */ + { 0, 74, 74, 0 }, { 0, 255, 74, 25 }, { 0, 97, 74, 0 }, { 0, 255, 74, 25 }, + { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6552 }, { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6552 } + }, { /* input: linear-rgb */ + { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 98, 0 }, { 0, 0, 98, 0 }, + { 0, 0, 18664, 0 }, { 0, 0, 18664, 0 }, { 0, 0, 24998, 0 }, { 0, 0, 24998, 0 } + }, { /* input: linear-rgb+alpha */ + { 0, 181, 196, 0 }, { 0, 255, 61, 25 }, { 206, 187, 98, 0 }, { 0, 255, 98, 67 }, + { 0, 18141, 18137, 0 }, { 0, 17494, 17504, 6553 }, { 0, 24979, 24992, 0 }, { 0, 46509, 24992, 17347 } + } +}; +/* END MACHINE GENERATED */ +#endif /* COLORMAP flag check */ +#endif /* flag checks */ + +typedef struct +{ + /* Basic pixel information: */ + Image* in_image; /* Input image */ + const Image* out_image; /* Output image */ + + /* 'background' is the value passed to the gpc_ routines, it may be NULL if + * it should not be used (*this* program has an error if it crashes as a + * result!) + */ + Background background_color; + const Background* background; + + /* Precalculated values: */ + int in_opaque; /* Value of input alpha that is opaque */ + int is_palette; /* Sample values come from the palette */ + int accumulate; /* Accumlate component errors (don't log) */ + int output_8bit; /* Output is 8 bit (else 16 bit) */ + + void (*in_gp)(Pixel*, png_const_voidp); + void (*out_gp)(Pixel*, png_const_voidp); + + void (*transform)(Pixel *out, const Pixel *in, const Background *back); + /* A function to perform the required transform */ + + void (*from_linear)(Pixel *out, const Pixel *in, const Background *back); + /* For 'via_linear' transforms the final, from linear, step, else NULL */ + + png_uint_16 error[4]; + /* Three error values for transparent, partially transparent and opaque + * input pixels (in turn). + */ + + png_uint_16 *error_ptr; + /* Where these are stored in the static array (for 'accumulate') */ +} +Transform; + +/* Return a 'transform' as above for the given format conversion. */ +static void +transform_from_formats(Transform *result, Image *in_image, + const Image *out_image, png_const_colorp background, int via_linear) +{ + png_uint_32 in_format, out_format; + png_uint_32 in_base, out_base; + + memset(result, 0, sizeof *result); + + /* Store the original images for error messages */ + result->in_image = in_image; + result->out_image = out_image; + + in_format = in_image->image.format; + out_format = out_image->image.format; + + if (in_format & PNG_FORMAT_FLAG_LINEAR) + result->in_opaque = 65535; + else + result->in_opaque = 255; + + result->output_8bit = (out_format & PNG_FORMAT_FLAG_LINEAR) == 0; + + result->is_palette = 0; /* set by caller if required */ + result->accumulate = (in_image->opts & ACCUMULATE) != 0; + + /* The loaders (which need the ordering information) */ + result->in_gp = get_pixel(in_format); + result->out_gp = get_pixel(out_format); + + /* Remove the ordering information: */ + in_format &= BASE_FORMATS | PNG_FORMAT_FLAG_COLORMAP; + in_base = in_format & BASE_FORMATS; + out_format &= BASE_FORMATS | PNG_FORMAT_FLAG_COLORMAP; + out_base = out_format & BASE_FORMATS; + + if (via_linear) + { + /* Check for an error in this program: */ + if (out_format & (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLORMAP)) + { + fprintf(stderr, "internal transform via linear error 0x%x->0x%x\n", + in_format, out_format); + exit(1); + } + + result->transform = gpc_fn[in_base][out_base | PNG_FORMAT_FLAG_LINEAR]; + result->from_linear = gpc_fn[out_base | PNG_FORMAT_FLAG_LINEAR][out_base]; + result->error_ptr = gpc_error_via_linear[in_format][out_format]; + } + + else if (~in_format & out_format & PNG_FORMAT_FLAG_COLORMAP) + { + /* The input is not colormapped but the output is, the errors will + * typically be large (only the grayscale-no-alpha case permits preserving + * even 8-bit values.) + */ + result->transform = gpc_fn[in_base][out_base]; + result->from_linear = NULL; + result->error_ptr = gpc_error_to_colormap[in_base][out_base]; + } + + else + { + /* The caller handles the colormap->pixel value conversion, so the + * transform function just gets a pixel value, however because libpng + * currently contains a different implementation for mapping a colormap if + * both input and output are colormapped we need different conversion + * functions to deal with errors in the libpng implementation. + */ + if (in_format & out_format & PNG_FORMAT_FLAG_COLORMAP) + result->transform = gpc_fn_colormapped[in_base][out_base]; + else + result->transform = gpc_fn[in_base][out_base]; + result->from_linear = NULL; + result->error_ptr = gpc_error[in_format][out_format]; + } + + /* Follow the libpng simplified API rules to work out what to pass to the gpc + * routines as a background value, if one is not required pass NULL so that + * this program crashes in the even of a programming error. + */ + result->background = NULL; /* default: not required */ + + /* Rule 1: background only need be supplied if alpha is to be removed */ + if (in_format & ~out_format & PNG_FORMAT_FLAG_ALPHA) + { + /* The input value is 'NULL' to use the background and (otherwise) an sRGB + * background color (to use a solid color). The code above uses a fixed + * byte value, BUFFER_INIT8, for buffer even for 16-bit output. For + * linear (16-bit) output the sRGB background color is ignored; the + * composition is always on the background (so BUFFER_INIT8 * 257), except + * that for the colormap (i.e. linear colormapped output) black is used. + */ + result->background = &result->background_color; + + if (out_format & PNG_FORMAT_FLAG_LINEAR || via_linear) + { + if (out_format & PNG_FORMAT_FLAG_COLORMAP) + { + result->background_color.ir = + result->background_color.ig = + result->background_color.ib = 0; + result->background_color.dr = + result->background_color.dg = + result->background_color.db = 0; + } + + else + { + result->background_color.ir = + result->background_color.ig = + result->background_color.ib = BUFFER_INIT8 * 257; + result->background_color.dr = + result->background_color.dg = + result->background_color.db = 0; + } + } + + else /* sRGB output */ + { + if (background != NULL) + { + if (out_format & PNG_FORMAT_FLAG_COLOR) + { + result->background_color.ir = background->red; + result->background_color.ig = background->green; + result->background_color.ib = background->blue; + /* TODO: sometimes libpng uses the power law conversion here, how + * to handle this? + */ + result->background_color.dr = sRGB_to_d[background->red]; + result->background_color.dg = sRGB_to_d[background->green]; + result->background_color.db = sRGB_to_d[background->blue]; + } + + else /* grayscale: libpng only looks at 'g' */ + { + result->background_color.ir = + result->background_color.ig = + result->background_color.ib = background->green; + /* TODO: sometimes libpng uses the power law conversion here, how + * to handle this? + */ + result->background_color.dr = + result->background_color.dg = + result->background_color.db = sRGB_to_d[background->green]; + } + } + + else if ((out_format & PNG_FORMAT_FLAG_COLORMAP) == 0) + { + result->background_color.ir = + result->background_color.ig = + result->background_color.ib = BUFFER_INIT8; + /* TODO: sometimes libpng uses the power law conversion here, how + * to handle this? + */ + result->background_color.dr = + result->background_color.dg = + result->background_color.db = sRGB_to_d[BUFFER_INIT8]; + } + + /* Else the output is colormapped and a background color must be + * provided; if pngstest crashes then that is a bug in this program + * (though libpng should png_error as well.) + */ + else + result->background = NULL; + } + } + + if (result->background == NULL) + { + result->background_color.ir = + result->background_color.ig = + result->background_color.ib = -1; /* not used */ + result->background_color.dr = + result->background_color.dg = + result->background_color.db = 1E30; /* not used */ + } + + + /* Copy the error values into the Transform: */ + result->error[0] = result->error_ptr[0]; + result->error[1] = result->error_ptr[1]; + result->error[2] = result->error_ptr[2]; + result->error[3] = result->error_ptr[3]; +} + + +/* Compare two pixels. + * + * OLD error values: +static int error_to_linear = 811; * by experiment * +static int error_to_linear_grayscale = 424; * by experiment * +static int error_to_sRGB = 6; * by experiment * +static int error_to_sRGB_grayscale = 17; * libpng error by calculation + + 2 by experiment * +static int error_in_compose = 2; * by experiment * +static int error_in_premultiply = 1; + * + * The following is *just* the result of a round trip from 8-bit sRGB to linear + * then back to 8-bit sRGB when it is done by libpng. There are two problems: + * + * 1) libpng currently uses a 2.2 power law with no linear segment, this results + * in instability in the low values and even with 16-bit precision sRGB(1) ends + * up mapping to sRGB(0) as a result of rounding in the 16-bit representation. + * This gives an error of 1 in the handling of value 1 only. + * + * 2) libpng currently uses an intermediate 8-bit linear value in gamma + * correction of 8-bit values. This results in many more errors, the worse of + * which is mapping sRGB(14) to sRGB(0). + * + * The general 'error_via_linear' is more complex because of pre-multiplication, + * this compounds the 8-bit errors according to the alpha value of the pixel. + * As a result 256 values are pre-calculated for error_via_linear. + */ +#if 0 +static int error_in_libpng_gamma; +static int error_via_linear[256]; /* Indexed by 8-bit alpha */ + +static void +init_error_via_linear(void) +{ + int alpha; + + error_via_linear[0] = 255; /* transparent pixel */ + + for (alpha=1; alpha<=255; ++alpha) + { + /* 16-bit values less than 128.5 get rounded to 8-bit 0 and so the worst + * case error arises with 16-bit 128.5, work out what sRGB + * (non-associated) value generates 128.5; any value less than this is + * going to map to 0, so the worst error is floor(value). + * + * Note that errors are considerably higher (more than a factor of 2) + * because libpng uses a simple power law for sRGB data at present. + * + * Add .1 for arithmetic errors inside libpng. + */ + double v = floor(255*pow(.5/*(128.5 * 255 / 65535)*/ / alpha, 1/2.2)+.1); + + error_via_linear[alpha] = (int)v; + } + + /* This is actually 14.99, but, despite the closeness to 15, 14 seems to work + * ok in this case. + */ + error_in_libpng_gamma = 14; +} +#endif + +static void +print_pixel(char string[64], const Pixel *pixel, png_uint_32 format) +{ + switch (format & (PNG_FORMAT_FLAG_ALPHA|PNG_FORMAT_FLAG_COLOR)) + { + case 0: + sprintf(string, "%s(%d)", format_names[format], pixel->g); + break; + + case PNG_FORMAT_FLAG_ALPHA: + sprintf(string, "%s(%d,%d)", format_names[format], pixel->g, + pixel->a); + break; + + case PNG_FORMAT_FLAG_COLOR: + sprintf(string, "%s(%d,%d,%d)", format_names[format], + pixel->r, pixel->g, pixel->b); + break; + + case PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA: + sprintf(string, "%s(%d,%d,%d,%d)", format_names[format], + pixel->r, pixel->g, pixel->b, pixel->a); + break; + + default: + sprintf(string, "invalid-format"); + break; + } +} + +static int +logpixel(const Transform *transform, png_uint_32 x, png_uint_32 y, + const Pixel *in, const Pixel *calc, const Pixel *out, const char *reason) +{ + const png_uint_32 in_format = transform->in_image->image.format; + const png_uint_32 out_format = transform->out_image->image.format; + + png_uint_32 back_format = out_format & ~PNG_FORMAT_FLAG_ALPHA; + const char *via_linear = ""; + + char pixel_in[64], pixel_calc[64], pixel_out[64], pixel_loc[64]; + char background_info[100]; + + print_pixel(pixel_in, in, in_format); + print_pixel(pixel_calc, calc, out_format); + print_pixel(pixel_out, out, out_format); + + if (transform->is_palette) + sprintf(pixel_loc, "palette: %lu", (unsigned long)y); + else + sprintf(pixel_loc, "%lu,%lu", (unsigned long)x, (unsigned long)y); + + if (transform->from_linear != NULL) + { + via_linear = " (via linear)"; + /* And as a result the *read* format which did any background processing + * was itself linear, so the background color information is also + * linear. + */ + back_format |= PNG_FORMAT_FLAG_LINEAR; + } + + if (transform->background != NULL) + { + Pixel back; + char pixel_back[64]; + + back.r = transform->background->ir; + back.g = transform->background->ig; + back.b = transform->background->ib; + back.a = -1; /* not used */ + + print_pixel(pixel_back, &back, back_format); + sprintf(background_info, " on background %s", pixel_back); + } + + else + background_info[0] = 0; + + if (transform->in_image->file_name != transform->out_image->file_name) + { + char error_buffer[512]; + sprintf(error_buffer, + "(%s) %s error%s:\n %s%s ->\n %s\n not: %s.\n" + "Use --preserve and examine: ", pixel_loc, reason, via_linear, + pixel_in, background_info, pixel_out, pixel_calc); + return logerror(transform->in_image, transform->in_image->file_name, + error_buffer, transform->out_image->file_name); + } + + else + { + char error_buffer[512]; + sprintf(error_buffer, + "(%s) %s error%s:\n %s%s ->\n %s\n not: %s.\n" + " The error happened when reading the original file with this format.", + pixel_loc, reason, via_linear, pixel_in, background_info, pixel_out, + pixel_calc); + return logerror(transform->in_image, transform->in_image->file_name, + error_buffer, ""); + } +} + +static int +cmppixel(Transform *transform, png_const_voidp in, png_const_voidp out, + png_uint_32 x, png_uint_32 y/*or palette index*/) +{ + int maxerr; + png_const_charp errmsg; + Pixel pixel_in, pixel_calc, pixel_out; + + transform->in_gp(&pixel_in, in); + + if (transform->from_linear == NULL) + transform->transform(&pixel_calc, &pixel_in, transform->background); + + else + { + transform->transform(&pixel_out, &pixel_in, transform->background); + transform->from_linear(&pixel_calc, &pixel_out, NULL); + } + + transform->out_gp(&pixel_out, out); + + /* Eliminate the case where the input and output values match exactly. */ + if (pixel_calc.a == pixel_out.a && pixel_calc.r == pixel_out.r && + pixel_calc.g == pixel_out.g && pixel_calc.b == pixel_out.b) + return 1; + + /* Eliminate the case where the output pixel is transparent and the output + * is 8-bit - any component values are valid. Don't check the input alpha + * here to also skip the 16-bit small alpha cases. + */ + if (transform->output_8bit && pixel_calc.a == 0 && pixel_out.a == 0) + return 1; + + /* Check for alpha errors first; an alpha error can damage the components too + * so avoid spurious checks on components if one is found. + */ + errmsg = NULL; + { + int err_a = abs(pixel_calc.a-pixel_out.a); + + if (err_a > transform->error[3]) + { + /* If accumulating check the components too */ + if (transform->accumulate) + transform->error[3] = (png_uint_16)err_a; + + else + errmsg = "alpha"; + } + } + + /* Now if *either* of the output alphas are 0 but alpha is within tolerance + * eliminate the 8-bit component comparison. + */ + if (errmsg == NULL && transform->output_8bit && + (pixel_calc.a == 0 || pixel_out.a == 0)) + return 1; + + if (errmsg == NULL) /* else just signal an alpha error */ + { + int err_r = abs(pixel_calc.r - pixel_out.r); + int err_g = abs(pixel_calc.g - pixel_out.g); + int err_b = abs(pixel_calc.b - pixel_out.b); + int limit; + + if ((err_r | err_g | err_b) == 0) + return 1; /* exact match */ + + /* Mismatch on a component, check the input alpha */ + if (pixel_in.a >= transform->in_opaque) + { + errmsg = "opaque component"; + limit = 2; /* opaque */ + } + + else if (pixel_in.a > 0) + { + errmsg = "alpha component"; + limit = 1; /* partially transparent */ + } + + else + { + errmsg = "transparent component (background)"; + limit = 0; /* transparent */ + } + + maxerr = err_r; + if (maxerr < err_g) maxerr = err_g; + if (maxerr < err_b) maxerr = err_b; + + if (maxerr <= transform->error[limit]) + return 1; /* within the error limits */ + + /* Handle a component mis-match; log it, just return an error code, or + * accumulate it. + */ + if (transform->accumulate) + { + transform->error[limit] = (png_uint_16)maxerr; + return 1; /* to cause the caller to keep going */ + } + } + + /* Failure to match and not accumulating, so the error must be logged. */ + return logpixel(transform, x, y, &pixel_in, &pixel_calc, &pixel_out, errmsg); +} + +static png_byte +component_loc(png_byte loc[4], png_uint_32 format) +{ + /* Given a format return the number of channels and the location of + * each channel. + * + * The mask 'loc' contains the component offset of the channels in the + * following order. Note that if 'format' is grayscale the entries 1-3 must + * all contain the location of the gray channel. + * + * 0: alpha + * 1: red or gray + * 2: green or gray + * 3: blue or gray + */ + png_byte channels; + + if (format & PNG_FORMAT_FLAG_COLOR) + { + channels = 3; + + loc[2] = 1; + +# ifdef PNG_FORMAT_BGR_SUPPORTED + if (format & PNG_FORMAT_FLAG_BGR) + { + loc[1] = 2; + loc[3] = 0; + } + + else +# endif + { + loc[1] = 0; + loc[3] = 2; + } + } + + else + { + channels = 1; + loc[1] = loc[2] = loc[3] = 0; + } + + if (format & PNG_FORMAT_FLAG_ALPHA) + { +# ifdef PNG_FORMAT_AFIRST_SUPPORTED + if (format & PNG_FORMAT_FLAG_AFIRST) + { + loc[0] = 0; + ++loc[1]; + ++loc[2]; + ++loc[3]; + } + + else +# endif + loc[0] = channels; + + ++channels; + } + + else + loc[0] = 4; /* not present */ + + return channels; +} + +/* Compare two images, the original 'a', which was written out then read back in + * to * give image 'b'. The formats may have been changed. + */ +static int +compare_two_images(Image *a, Image *b, int via_linear, + png_const_colorp background) +{ + ptrdiff_t stridea = a->stride; + ptrdiff_t strideb = b->stride; + png_const_bytep rowa = a->buffer+16; + png_const_bytep rowb = b->buffer+16; + const png_uint_32 width = a->image.width; + const png_uint_32 height = a->image.height; + const png_uint_32 formata = a->image.format; + const png_uint_32 formatb = b->image.format; + const unsigned int a_sample = PNG_IMAGE_SAMPLE_SIZE(formata); + const unsigned int b_sample = PNG_IMAGE_SAMPLE_SIZE(formatb); + int alpha_added, alpha_removed; + int bchannels; + int btoa[4]; + png_uint_32 y; + Transform tr; + + /* This should never happen: */ + if (width != b->image.width || height != b->image.height) + return logerror(a, a->file_name, ": width x height changed: ", + b->file_name); + + /* Set up the background and the transform */ + transform_from_formats(&tr, a, b, background, via_linear); + + /* Find the first row and inter-row space. */ + if (!(formata & PNG_FORMAT_FLAG_COLORMAP) && + (formata & PNG_FORMAT_FLAG_LINEAR)) + stridea *= 2; + + if (!(formatb & PNG_FORMAT_FLAG_COLORMAP) && + (formatb & PNG_FORMAT_FLAG_LINEAR)) + strideb *= 2; + + if (stridea < 0) rowa += (height-1) * (-stridea); + if (strideb < 0) rowb += (height-1) * (-strideb); + + /* First shortcut the two colormap case by comparing the image data; if it + * matches then we expect the colormaps to match, although this is not + * absolutely necessary for an image match. If the colormaps fail to match + * then there is a problem in libpng. + */ + if (formata & formatb & PNG_FORMAT_FLAG_COLORMAP) + { + /* Only check colormap entries that actually exist; */ + png_const_bytep ppa, ppb; + int match; + png_byte in_use[256], amax = 0, bmax = 0; + + memset(in_use, 0, sizeof in_use); + + ppa = rowa; + ppb = rowb; + + /* Do this the slow way to accumulate the 'in_use' flags, don't break out + * of the loop until the end; this validates the color-mapped data to + * ensure all pixels are valid color-map indexes. + */ + for (y=0, match=1; y<height && match; ++y, ppa += stridea, ppb += strideb) + { + png_uint_32 x; + + for (x=0; x<width; ++x) + { + png_byte bval = ppb[x]; + png_byte aval = ppa[x]; + + if (bval > bmax) + bmax = bval; + + if (bval != aval) + match = 0; + + in_use[aval] = 1; + if (aval > amax) + amax = aval; + } + } + + /* If the buffers match then the colormaps must too. */ + if (match) + { + /* Do the color-maps match, entry by entry? Only check the 'in_use' + * entries. An error here should be logged as a color-map error. + */ + png_const_bytep a_cmap = (png_const_bytep)a->colormap; + png_const_bytep b_cmap = (png_const_bytep)b->colormap; + int result = 1; /* match by default */ + + /* This is used in logpixel to get the error message correct. */ + tr.is_palette = 1; + + for (y=0; y<256; ++y, a_cmap += a_sample, b_cmap += b_sample) + if (in_use[y]) + { + /* The colormap entries should be valid, but because libpng doesn't + * do any checking at present the original image may contain invalid + * pixel values. These cause an error here (at present) unless + * accumulating errors in which case the program just ignores them. + */ + if (y >= a->image.colormap_entries) + { + if ((a->opts & ACCUMULATE) == 0) + { + char pindex[9]; + sprintf(pindex, "%lu[%lu]", (unsigned long)y, + (unsigned long)a->image.colormap_entries); + logerror(a, a->file_name, ": bad pixel index: ", pindex); + } + result = 0; + } + + else if (y >= b->image.colormap_entries) + { + if ((a->opts & ACCUMULATE) == 0) + { + char pindex[9]; + sprintf(pindex, "%lu[%lu]", (unsigned long)y, + (unsigned long)b->image.colormap_entries); + logerror(b, b->file_name, ": bad pixel index: ", pindex); + } + result = 0; + } + + /* All the mismatches are logged here; there can only be 256! */ + else if (!cmppixel(&tr, a_cmap, b_cmap, 0, y)) + result = 0; + } + + /* If reqested copy the error values back from the Transform. */ + if (a->opts & ACCUMULATE) + { + tr.error_ptr[0] = tr.error[0]; + tr.error_ptr[1] = tr.error[1]; + tr.error_ptr[2] = tr.error[2]; + tr.error_ptr[3] = tr.error[3]; + result = 1; /* force a continue */ + } + + return result; + } + + /* else the image buffers don't match pixel-wise so compare sample values + * instead, but first validate that the pixel indexes are in range (but + * only if not accumulating, when the error is ignored.) + */ + else if ((a->opts & ACCUMULATE) == 0) + { + /* Check the original image first, + * TODO: deal with input images with bad pixel values? + */ + if (amax >= a->image.colormap_entries) + { + char pindex[9]; + sprintf(pindex, "%d[%lu]", amax, + (unsigned long)a->image.colormap_entries); + return logerror(a, a->file_name, ": bad pixel index: ", pindex); + } + + else if (bmax >= b->image.colormap_entries) + { + char pindex[9]; + sprintf(pindex, "%d[%lu]", bmax, + (unsigned long)b->image.colormap_entries); + return logerror(b, b->file_name, ": bad pixel index: ", pindex); + } + } + } + + /* We can directly compare pixel values without the need to use the read + * or transform support (i.e. a memory compare) if: + * + * 1) The bit depth has not changed. + * 2) RGB to grayscale has not been done (the reverse is ok; we just compare + * the three RGB values to the original grayscale.) + * 3) An alpha channel has not been removed from an 8-bit format, or the + * 8-bit alpha value of the pixel was 255 (opaque). + * + * If an alpha channel has been *added* then it must have the relevant opaque + * value (255 or 65535). + * + * The fist two the tests (in the order given above) (using the boolean + * equivalence !a && !b == !(a || b)) + */ + if (!(((formata ^ formatb) & PNG_FORMAT_FLAG_LINEAR) | + (formata & (formatb ^ PNG_FORMAT_FLAG_COLOR) & PNG_FORMAT_FLAG_COLOR))) + { + /* Was an alpha channel changed? */ + const png_uint_32 alpha_changed = (formata ^ formatb) & + PNG_FORMAT_FLAG_ALPHA; + + /* Was an alpha channel removed? (The third test.) If so the direct + * comparison is only possible if the input alpha is opaque. + */ + alpha_removed = (formata & alpha_changed) != 0; + + /* Was an alpha channel added? */ + alpha_added = (formatb & alpha_changed) != 0; + + /* The channels may have been moved between input and output, this finds + * out how, recording the result in the btoa array, which says where in + * 'a' to find each channel of 'b'. If alpha was added then btoa[alpha] + * ends up as 4 (and is not used.) + */ + { + int i; + png_byte aloc[4]; + png_byte bloc[4]; + + /* The following are used only if the formats match, except that + * 'bchannels' is a flag for matching formats. btoa[x] says, for each + * channel in b, where to find the corresponding value in a, for the + * bchannels. achannels may be different for a gray to rgb transform + * (a will be 1 or 2, b will be 3 or 4 channels.) + */ + (void)component_loc(aloc, formata); + bchannels = component_loc(bloc, formatb); + + /* Hence the btoa array. */ + for (i=0; i<4; ++i) if (bloc[i] < 4) + btoa[bloc[i]] = aloc[i]; /* may be '4' for alpha */ + + if (alpha_added) + alpha_added = bloc[0]; /* location of alpha channel in image b */ + + else + alpha_added = 4; /* Won't match an image b channel */ + + if (alpha_removed) + alpha_removed = aloc[0]; /* location of alpha channel in image a */ + + else + alpha_removed = 4; + } + } + + else + { + /* Direct compare is not possible, cancel out all the corresponding local + * variables. + */ + bchannels = 0; + alpha_removed = alpha_added = 4; + btoa[3] = btoa[2] = btoa[1] = btoa[0] = 4; /* 4 == not present */ + } + + for (y=0; y<height; ++y, rowa += stridea, rowb += strideb) + { + png_const_bytep ppa, ppb; + png_uint_32 x; + + for (x=0, ppa=rowa, ppb=rowb; x<width; ++x) + { + png_const_bytep psa, psb; + + if (formata & PNG_FORMAT_FLAG_COLORMAP) + psa = (png_const_bytep)a->colormap + a_sample * *ppa++; + else + psa = ppa, ppa += a_sample; + + if (formatb & PNG_FORMAT_FLAG_COLORMAP) + psb = (png_const_bytep)b->colormap + b_sample * *ppb++; + else + psb = ppb, ppb += b_sample; + + /* Do the fast test if possible. */ + if (bchannels) + { + /* Check each 'b' channel against either the corresponding 'a' + * channel or the opaque alpha value, as appropriate. If + * alpha_removed value is set (not 4) then also do this only if the + * 'a' alpha channel (alpha_removed) is opaque; only relevant for + * the 8-bit case. + */ + if (formatb & PNG_FORMAT_FLAG_LINEAR) /* 16-bit checks */ + { + png_const_uint_16p pua = aligncastconst(png_const_uint_16p, psa); + png_const_uint_16p pub = aligncastconst(png_const_uint_16p, psb); + + switch (bchannels) + { + case 4: + if (pua[btoa[3]] != pub[3]) break; + case 3: + if (pua[btoa[2]] != pub[2]) break; + case 2: + if (pua[btoa[1]] != pub[1]) break; + case 1: + if (pua[btoa[0]] != pub[0]) break; + if (alpha_added != 4 && pub[alpha_added] != 65535) break; + continue; /* x loop */ + default: + break; /* impossible */ + } + } + + else if (alpha_removed == 4 || psa[alpha_removed] == 255) + { + switch (bchannels) + { + case 4: + if (psa[btoa[3]] != psb[3]) break; + case 3: + if (psa[btoa[2]] != psb[2]) break; + case 2: + if (psa[btoa[1]] != psb[1]) break; + case 1: + if (psa[btoa[0]] != psb[0]) break; + if (alpha_added != 4 && psb[alpha_added] != 255) break; + continue; /* x loop */ + default: + break; /* impossible */ + } + } + } + + /* If we get to here the fast match failed; do the slow match for this + * pixel. + */ + if (!cmppixel(&tr, psa, psb, x, y) && (a->opts & KEEP_GOING) == 0) + return 0; /* error case */ + } + } + + /* If reqested copy the error values back from the Transform. */ + if (a->opts & ACCUMULATE) + { + tr.error_ptr[0] = tr.error[0]; + tr.error_ptr[1] = tr.error[1]; + tr.error_ptr[2] = tr.error[2]; + tr.error_ptr[3] = tr.error[3]; + } + + return 1; +} + +/* Read the file; how the read gets done depends on which of input_file and + * input_memory have been set. + */ +static int +read_file(Image *image, png_uint_32 format, png_const_colorp background) +{ + memset(&image->image, 0, sizeof image->image); + image->image.version = PNG_IMAGE_VERSION; + + if (image->input_memory != NULL) + { + if (!png_image_begin_read_from_memory(&image->image, image->input_memory, + image->input_memory_size)) + return logerror(image, "memory init: ", image->file_name, ""); + } + +# ifdef PNG_STDIO_SUPPORTED + else if (image->input_file != NULL) + { + if (!png_image_begin_read_from_stdio(&image->image, image->input_file)) + return logerror(image, "stdio init: ", image->file_name, ""); + } + + else + { + if (!png_image_begin_read_from_file(&image->image, image->file_name)) + return logerror(image, "file init: ", image->file_name, ""); + } +# else + else + { + return logerror(image, "unsupported file/stdio init: ", + image->file_name, ""); + } +# endif + + /* This must be set after the begin_read call: */ + if (image->opts & sRGB_16BIT) + image->image.flags |= PNG_IMAGE_FLAG_16BIT_sRGB; + + /* Have an initialized image with all the data we need plus, maybe, an + * allocated file (myfile) or buffer (mybuffer) that need to be freed. + */ + { + int result; + png_uint_32 image_format; + + /* Print both original and output formats. */ + image_format = image->image.format; + + if (image->opts & VERBOSE) + { + printf("%s %lu x %lu %s -> %s", image->file_name, + (unsigned long)image->image.width, + (unsigned long)image->image.height, + format_names[image_format & FORMAT_MASK], + (format & FORMAT_NO_CHANGE) != 0 || image->image.format == format + ? "no change" : format_names[format & FORMAT_MASK]); + + if (background != NULL) + printf(" background(%d,%d,%d)\n", background->red, + background->green, background->blue); + else + printf("\n"); + + fflush(stdout); + } + + /* 'NO_CHANGE' combined with the color-map flag forces the base format + * flags to be set on read to ensure that the original representation is + * not lost in the pass through a colormap format. + */ + if ((format & FORMAT_NO_CHANGE) != 0) + { + if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0 && + (image_format & PNG_FORMAT_FLAG_COLORMAP) != 0) + format = (image_format & ~BASE_FORMATS) | (format & BASE_FORMATS); + + else + format = image_format; + } + + image->image.format = format; + + image->stride = PNG_IMAGE_ROW_STRIDE(image->image) + image->stride_extra; + allocbuffer(image); + + result = png_image_finish_read(&image->image, background, + image->buffer+16, (png_int_32)image->stride, image->colormap); + + checkbuffer(image, image->file_name); + + if (result) + return checkopaque(image); + + else + return logerror(image, image->file_name, ": image read failed", ""); + } +} + +/* Reads from a filename, which must be in image->file_name, but uses + * image->opts to choose the method. The file is always read in its native + * format (the one the simplified API suggests). + */ +static int +read_one_file(Image *image) +{ + if (!(image->opts & READ_FILE) || (image->opts & USE_STDIO)) + { + /* memory or stdio. */ + FILE *f = fopen(image->file_name, "rb"); + + if (f != NULL) + { + if (image->opts & READ_FILE) + image->input_file = f; + + else /* memory */ + { + if (fseek(f, 0, SEEK_END) == 0) + { + long int cb = ftell(f); + + if (cb > 0) + { + if ((unsigned long int)cb <= (size_t)~(size_t)0) + { + png_bytep b = voidcast(png_bytep, malloc((size_t)cb)); + + if (b != NULL) + { + rewind(f); + + if (fread(b, (size_t)cb, 1, f) == 1) + { + fclose(f); + image->input_memory_size = cb; + image->input_memory = b; + } + + else + { + free(b); + return logclose(image, f, image->file_name, + ": read failed: "); + } + } + + else + return logclose(image, f, image->file_name, + ": out of memory: "); + } + + else + return logclose(image, f, image->file_name, + ": file too big for this architecture: "); + /* cb is the length of the file as a (long) and + * this is greater than the maximum amount of + * memory that can be requested from malloc. + */ + } + + else if (cb == 0) + return logclose(image, f, image->file_name, + ": zero length: "); + + else + return logclose(image, f, image->file_name, + ": tell failed: "); + } + + else + return logclose(image, f, image->file_name, ": seek failed: "); + } + } + + else + return logerror(image, image->file_name, ": open failed: ", + strerror(errno)); + } + + return read_file(image, FORMAT_NO_CHANGE, NULL); +} + +#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED +static int +write_one_file(Image *output, Image *image, int convert_to_8bit) +{ + if (image->opts & FAST_WRITE) + image->image.flags |= PNG_IMAGE_FLAG_FAST; + + if (image->opts & USE_STDIO) + { + FILE *f = tmpfile(); + + if (f != NULL) + { + if (png_image_write_to_stdio(&image->image, f, convert_to_8bit, + image->buffer+16, (png_int_32)image->stride, image->colormap)) + { + if (fflush(f) == 0) + { + rewind(f); + initimage(output, image->opts, "tmpfile", image->stride_extra); + output->input_file = f; + if (!checkopaque(image)) + return 0; + } + + else + return logclose(image, f, "tmpfile", ": flush: "); + } + + else + { + fclose(f); + return logerror(image, "tmpfile", ": write failed", ""); + } + } + + else + return logerror(image, "tmpfile", ": open: ", strerror(errno)); + } + + else + { + static int counter = 0; + char name[32]; + + sprintf(name, "%s%d.png", tmpf, ++counter); + + if (png_image_write_to_file(&image->image, name, convert_to_8bit, + image->buffer+16, (png_int_32)image->stride, image->colormap)) + { + initimage(output, image->opts, output->tmpfile_name, + image->stride_extra); + /* Afterwards, or freeimage will delete it! */ + strcpy(output->tmpfile_name, name); + + if (!checkopaque(image)) + return 0; + } + + else + return logerror(image, name, ": write failed", ""); + } + + /* 'output' has an initialized temporary image, read this back in and compare + * this against the original: there should be no change since the original + * format was written unmodified unless 'convert_to_8bit' was specified. + * However, if the original image was color-mapped, a simple read will zap + * the linear, color and maybe alpha flags, this will cause spurious failures + * under some circumstances. + */ + if (read_file(output, image->image.format | FORMAT_NO_CHANGE, NULL)) + { + png_uint_32 original_format = image->image.format; + + if (convert_to_8bit) + original_format &= ~PNG_FORMAT_FLAG_LINEAR; + + if ((output->image.format & BASE_FORMATS) != + (original_format & BASE_FORMATS)) + return logerror(image, image->file_name, ": format changed on read: ", + output->file_name); + + return compare_two_images(image, output, 0/*via linear*/, NULL); + } + + else + return logerror(output, output->tmpfile_name, + ": read of new file failed", ""); +} +#endif + +static int +testimage(Image *image, png_uint_32 opts, format_list *pf) +{ + int result; + Image copy; + + /* Copy the original data, stealing it from 'image' */ + checkopaque(image); + copy = *image; + + copy.opts = opts; + copy.buffer = NULL; + copy.bufsize = 0; + copy.allocsize = 0; + + image->input_file = NULL; + image->input_memory = NULL; + image->input_memory_size = 0; + image->tmpfile_name[0] = 0; + + { + png_uint_32 counter; + Image output; + + newimage(&output); + + result = 1; + + /* Use the low bit of 'counter' to indicate whether or not to do alpha + * removal with a background color or by composting onto the image; this + * step gets skipped if it isn't relevant + */ + for (counter=0; counter<2*FORMAT_COUNT; ++counter) + if (format_isset(pf, counter >> 1)) + { + png_uint_32 format = counter >> 1; + + png_color background_color; + png_colorp background = NULL; + + /* If there is a format change that removes the alpha channel then + * the background is relevant. If the output is 8-bit color-mapped + * then a background color *must* be provided, otherwise there are + * two tests to do - one with a color, the other with NULL. The + * NULL test happens second. + */ + if ((counter & 1) == 0) + { + if ((format & PNG_FORMAT_FLAG_ALPHA) == 0 && + (image->image.format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + /* Alpha/transparency will be removed, the background is + * relevant: make it a color the first time + */ + random_color(&background_color); + background = &background_color; + + /* BUT if the output is to a color-mapped 8-bit format then + * the background must always be a color, so increment 'counter' + * to skip the NULL test. + */ + if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0 && + (format & PNG_FORMAT_FLAG_LINEAR) == 0) + ++counter; + } + + /* Otherwise an alpha channel is not being eliminated, just leave + * background NULL and skip the (counter & 1) NULL test. + */ + else + ++counter; + } + /* else just use NULL for background */ + + resetimage(©); + copy.opts = opts; /* in case read_file needs to change it */ + + result = read_file(©, format, background); + if (!result) + break; + + /* Make sure the file just read matches the original file. */ + result = compare_two_images(image, ©, 0/*via linear*/, background); + if (!result) + break; + +# ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED + /* Write the *copy* just made to a new file to make sure the write + * side works ok. Check the conversion to sRGB if the copy is + * linear. + */ + output.opts = opts; + result = write_one_file(&output, ©, 0/*convert to 8bit*/); + if (!result) + break; + + /* Validate against the original too; the background is needed here + * as well so that compare_two_images knows what color was used. + */ + result = compare_two_images(image, &output, 0, background); + if (!result) + break; + + if ((format & PNG_FORMAT_FLAG_LINEAR) != 0 && + (format & PNG_FORMAT_FLAG_COLORMAP) == 0) + { + /* 'output' is linear, convert to the corresponding sRGB format. + */ + output.opts = opts; + result = write_one_file(&output, ©, 1/*convert to 8bit*/); + if (!result) + break; + + /* This may involve a conversion via linear; in the ideal world + * this would round-trip correctly, but libpng 1.5.7 is not the + * ideal world so allow a drift (error_via_linear). + * + * 'image' has an alpha channel but 'output' does not then there + * will a strip-alpha-channel operation (because 'output' is + * linear), handle this by composing on black when doing the + * comparison. + */ + result = compare_two_images(image, &output, 1/*via_linear*/, + background); + if (!result) + break; + } +# endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */ + } + + freeimage(&output); + } + + freeimage(©); + + return result; +} + +static int +test_one_file(const char *file_name, format_list *formats, png_uint_32 opts, + int stride_extra, int log_pass) +{ + int result; + Image image; + + newimage(&image); + initimage(&image, opts, file_name, stride_extra); + result = read_one_file(&image); + if (result) + result = testimage(&image, opts, formats); + freeimage(&image); + + /* Ensure that stderr is flushed into any log file */ + fflush(stderr); + + if (log_pass) + { + if (result) + printf("PASS:"); + + else + printf("FAIL:"); + +# ifndef PNG_SIMPLIFIED_WRITE_SUPPORTED + printf(" (no write)"); +# endif + + print_opts(opts); + printf(" %s\n", file_name); + /* stdout may not be line-buffered if it is piped to a file, so: */ + fflush(stdout); + } + + else if (!result) + exit(1); + + return result; +} + +int +main(int argc, char **argv) +{ + png_uint_32 opts = FAST_WRITE; + format_list formats; + const char *touch = NULL; + int log_pass = 0; + int redundant = 0; + int stride_extra = 0; + int retval = 0; + int c; + + init_sRGB_to_d(); +#if 0 + init_error_via_linear(); +#endif + format_init(&formats); + + for (c=1; c<argc; ++c) + { + const char *arg = argv[c]; + + if (strcmp(arg, "--log") == 0) + log_pass = 1; + else if (strcmp(arg, "--fresh") == 0) + { + memset(gpc_error, 0, sizeof gpc_error); + memset(gpc_error_via_linear, 0, sizeof gpc_error_via_linear); + } + else if (strcmp(arg, "--file") == 0) +# ifdef PNG_STDIO_SUPPORTED + opts |= READ_FILE; +# else + return 77; /* skipped: no support */ +# endif + else if (strcmp(arg, "--memory") == 0) + opts &= ~READ_FILE; + else if (strcmp(arg, "--stdio") == 0) +# ifdef PNG_STDIO_SUPPORTED + opts |= USE_STDIO; +# else + return 77; /* skipped: no support */ +# endif + else if (strcmp(arg, "--name") == 0) + opts &= ~USE_STDIO; + else if (strcmp(arg, "--verbose") == 0) + opts |= VERBOSE; + else if (strcmp(arg, "--quiet") == 0) + opts &= ~VERBOSE; + else if (strcmp(arg, "--preserve") == 0) + opts |= KEEP_TMPFILES; + else if (strcmp(arg, "--nopreserve") == 0) + opts &= ~KEEP_TMPFILES; + else if (strcmp(arg, "--keep-going") == 0) + opts |= KEEP_GOING; + else if (strcmp(arg, "--fast") == 0) + opts |= FAST_WRITE; + else if (strcmp(arg, "--slow") == 0) + opts &= ~FAST_WRITE; + else if (strcmp(arg, "--accumulate") == 0) + opts |= ACCUMULATE; + else if (strcmp(arg, "--redundant") == 0) + redundant = 1; + else if (strcmp(arg, "--stop") == 0) + opts &= ~KEEP_GOING; + else if (strcmp(arg, "--strict") == 0) + opts |= STRICT; + else if (strcmp(arg, "--sRGB-16bit") == 0) + opts |= sRGB_16BIT; + else if (strcmp(arg, "--linear-16bit") == 0) + opts &= ~sRGB_16BIT; + else if (strcmp(arg, "--tmpfile") == 0) + { + if (c+1 < argc) + { + if (strlen(argv[++c]) >= sizeof tmpf) + { + fflush(stdout); + fprintf(stderr, "%s: %s is too long for a temp file prefix\n", + argv[0], argv[c]); + exit(99); + } + + /* Safe: checked above */ + strcpy(tmpf, argv[c]); + } + + else + { + fflush(stdout); + fprintf(stderr, "%s: %s requires a temporary file prefix\n", + argv[0], arg); + exit(99); + } + } + else if (strcmp(arg, "--touch") == 0) + { + if (c+1 < argc) + touch = argv[++c]; + + else + { + fflush(stdout); + fprintf(stderr, "%s: %s requires a file name argument\n", + argv[0], arg); + exit(99); + } + } + else if (arg[0] == '+') + { + png_uint_32 format = formatof(arg+1); + + if (format > FORMAT_COUNT) + exit(99); + + format_set(&formats, format); + } + else if (arg[0] == '-' && arg[1] != 0 && (arg[1] != '0' || arg[2] != 0)) + { + fflush(stdout); + fprintf(stderr, "%s: unknown option: %s\n", argv[0], arg); + exit(99); + } + else + { + if (format_is_initial(&formats)) + format_default(&formats, redundant); + + if (arg[0] == '-') + { + const int term = (arg[1] == '0' ? 0 : '\n'); + unsigned int ich = 0; + + /* Loop reading files, use a static buffer to simplify this and just + * stop if the name gets to long. + */ + static char buffer[4096]; + + do + { + int ch = getchar(); + + /* Don't allow '\0' in file names, and terminate with '\n' or, + * for -0, just '\0' (use -print0 to find to make this work!) + */ + if (ch == EOF || ch == term || ch == 0) + { + buffer[ich] = 0; + + if (ich > 0 && !test_one_file(buffer, &formats, opts, + stride_extra, log_pass)) + retval = 1; + + if (ch == EOF) + break; + + ich = 0; + --ich; /* so that the increment below sets it to 0 again */ + } + + else + buffer[ich] = (char)ch; + } while (++ich < sizeof buffer); + + if (ich) + { + buffer[32] = 0; + buffer[4095] = 0; + fprintf(stderr, "%s...%s: file name too long\n", buffer, + buffer+(4096-32)); + exit(99); + } + } + + else if (!test_one_file(arg, &formats, opts, stride_extra, log_pass)) + retval = 1; + } + } + + if (opts & ACCUMULATE) + { + unsigned int in; + + printf("static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =\n"); + printf("{\n"); + for (in=0; in<16; ++in) + { + unsigned int out; + printf(" { /* input: %s */\n ", format_names[in]); + for (out=0; out<16; ++out) + { + unsigned int alpha; + printf(" {"); + for (alpha=0; alpha<4; ++alpha) + { + printf(" %d", gpc_error[in][out][alpha]); + if (alpha < 3) putchar(','); + } + printf(" }"); + if (out < 15) + { + putchar(','); + if (out % 4 == 3) printf("\n "); + } + } + printf("\n }"); + + if (in < 15) + putchar(','); + else + putchar('\n'); + } + printf("};\n"); + + printf("static png_uint_16 gpc_error_via_linear[16][4/*out*/][4] =\n"); + printf("{\n"); + for (in=0; in<16; ++in) + { + unsigned int out; + printf(" { /* input: %s */\n ", format_names[in]); + for (out=0; out<4; ++out) + { + unsigned int alpha; + printf(" {"); + for (alpha=0; alpha<4; ++alpha) + { + printf(" %d", gpc_error_via_linear[in][out][alpha]); + if (alpha < 3) putchar(','); + } + printf(" }"); + if (out < 3) + putchar(','); + } + printf("\n }"); + + if (in < 15) + putchar(','); + else + putchar('\n'); + } + printf("};\n"); + + printf("static png_uint_16 gpc_error_to_colormap[8/*i*/][8/*o*/][4] =\n"); + printf("{\n"); + for (in=0; in<8; ++in) + { + unsigned int out; + printf(" { /* input: %s */\n ", format_names[in]); + for (out=0; out<8; ++out) + { + unsigned int alpha; + printf(" {"); + for (alpha=0; alpha<4; ++alpha) + { + printf(" %d", gpc_error_to_colormap[in][out][alpha]); + if (alpha < 3) putchar(','); + } + printf(" }"); + if (out < 7) + { + putchar(','); + if (out % 4 == 3) printf("\n "); + } + } + printf("\n }"); + + if (in < 7) + putchar(','); + else + putchar('\n'); + } + printf("};\n"); + } + + if (retval == 0 && touch != NULL) + { + FILE *fsuccess = fopen(touch, "wt"); + + if (fsuccess != NULL) + { + int error = 0; + fprintf(fsuccess, "PNG simple API tests succeeded\n"); + fflush(fsuccess); + error = ferror(fsuccess); + + if (fclose(fsuccess) || error) + { + fflush(stdout); + fprintf(stderr, "%s: write failed\n", touch); + exit(99); + } + } + + else + { + fflush(stdout); + fprintf(stderr, "%s: open failed\n", touch); + exit(99); + } + } + + return retval; +} + +#else /* !PNG_SIMPLIFIED_READ_SUPPORTED */ +int main(void) +{ + fprintf(stderr, "pngstest: no read support in libpng, test skipped\n"); + /* So the test is skipped: */ + return 77; +} +#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */ diff --git a/libpng/contrib/libtests/pngunknown.c b/libpng/contrib/libtests/pngunknown.c new file mode 100644 index 000000000..309ee604e --- /dev/null +++ b/libpng/contrib/libtests/pngunknown.c @@ -0,0 +1,1245 @@ + +/* pngunknown.c - test the read side unknown chunk handling + * + * Last changed in libpng 1.6.10 [March 6, 2014] + * Copyright (c) 2014 Glenn Randers-Pehrson + * Written by John Cunningham Bowler + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * NOTES: + * This is a C program that is intended to be linked against libpng. It + * allows the libpng unknown handling code to be tested by interpreting + * arguments to save or discard combinations of chunks. The program is + * currently just a minimal validation for the built-in libpng facilities. + */ + +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <setjmp.h> + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +/* Since this program tests the ability to change the unknown chunk handling + * these must be defined: + */ +#if defined(PNG_SET_UNKNOWN_CHUNKS_SUPPORTED) &&\ + defined(PNG_READ_SUPPORTED) + +/* One of these must be defined to allow us to find out what happened. It is + * still useful to set unknown chunk handling without either of these in order + * to cause *known* chunks to be discarded. This can be a significant + * efficiency gain, but it can't really be tested here. + */ +#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) ||\ + defined(PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED) + +#if PNG_LIBPNG_VER < 10500 +/* This deliberately lacks the PNG_CONST. */ +typedef png_byte *png_const_bytep; + +/* This is copied from 1.5.1 png.h: */ +#define PNG_INTERLACE_ADAM7_PASSES 7 +#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ + -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ + -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) +#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ + (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) +#define PNG_COL_FROM_PASS_COL(xIn, pass) \ + (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) +#define PNG_PASS_MASK(pass,off) ( \ + ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \ + ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +/* These are needed too for the default build: */ +#define PNG_WRITE_16BIT_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED + +/* This comes from pnglibconf.h afer 1.5: */ +#define PNG_FP_1 100000 +#define PNG_GAMMA_THRESHOLD_FIXED\ + ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1)) +#endif + +#if PNG_LIBPNG_VER < 10600 + /* 1.6.0 constifies many APIs. The following exists to allow pngvalid to be + * compiled against earlier versions. + */ +# define png_const_structp png_structp +#endif + +#if PNG_LIBPNG_VER < 10700 + /* Copied from libpng 1.7.0 png.h */ +#define PNG_u2(b1, b2) (((unsigned int)(b1) << 8) + (b2)) + +#define PNG_U16(b1, b2) ((png_uint_16)PNG_u2(b1, b2)) +#define PNG_U32(b1, b2, b3, b4)\ + (((png_uint_32)PNG_u2(b1, b2) << 16) + PNG_u2(b3, b4)) + +/* Constants for known chunk types. + */ +#define png_IDAT PNG_U32( 73, 68, 65, 84) +#define png_IEND PNG_U32( 73, 69, 78, 68) +#define png_IHDR PNG_U32( 73, 72, 68, 82) +#define png_PLTE PNG_U32( 80, 76, 84, 69) +#define png_bKGD PNG_U32( 98, 75, 71, 68) +#define png_cHRM PNG_U32( 99, 72, 82, 77) +#define png_fRAc PNG_U32(102, 82, 65, 99) /* registered, not defined */ +#define png_gAMA PNG_U32(103, 65, 77, 65) +#define png_gIFg PNG_U32(103, 73, 70, 103) +#define png_gIFt PNG_U32(103, 73, 70, 116) /* deprecated */ +#define png_gIFx PNG_U32(103, 73, 70, 120) +#define png_hIST PNG_U32(104, 73, 83, 84) +#define png_iCCP PNG_U32(105, 67, 67, 80) +#define png_iTXt PNG_U32(105, 84, 88, 116) +#define png_oFFs PNG_U32(111, 70, 70, 115) +#define png_pCAL PNG_U32(112, 67, 65, 76) +#define png_pHYs PNG_U32(112, 72, 89, 115) +#define png_sBIT PNG_U32(115, 66, 73, 84) +#define png_sCAL PNG_U32(115, 67, 65, 76) +#define png_sPLT PNG_U32(115, 80, 76, 84) +#define png_sRGB PNG_U32(115, 82, 71, 66) +#define png_sTER PNG_U32(115, 84, 69, 82) +#define png_tEXt PNG_U32(116, 69, 88, 116) +#define png_tIME PNG_U32(116, 73, 77, 69) +#define png_tRNS PNG_U32(116, 82, 78, 83) +#define png_zTXt PNG_U32(122, 84, 88, 116) + +/* Test on flag values as defined in the spec (section 5.4): */ +#define PNG_CHUNK_ANCILLARY(c) (1 & ((c) >> 29)) +#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c)) +#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21)) +#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13)) +#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5)) + +#endif /* PNG_LIBPNG_VER < 10700 */ + +#ifdef __cplusplus +# define this not_the_cpp_this +# define new not_the_cpp_new +# define voidcast(type, value) static_cast<type>(value) +#else +# define voidcast(type, value) (value) +#endif /* __cplusplus */ + +/* Unused formal parameter errors are removed using the following macro which is + * expected to have no bad effects on performance. + */ +#ifndef UNUSED +# if defined(__GNUC__) || defined(_MSC_VER) +# define UNUSED(param) (void)param; +# else +# define UNUSED(param) +# endif +#endif + +/* Types of chunks not known to libpng */ +#define png_vpAg PNG_U32(118, 112, 65, 103) + +/* Chunk information */ +#define PNG_INFO_tEXt 0x10000000U +#define PNG_INFO_iTXt 0x20000000U +#define PNG_INFO_zTXt 0x40000000U + +#define PNG_INFO_sTER 0x01000000U +#define PNG_INFO_vpAg 0x02000000U + +#define ABSENT 0 +#define START 1 +#define END 2 + +static struct +{ + char name[5]; + png_uint_32 flag; + png_uint_32 tag; + int unknown; /* Chunk not known to libpng */ + int all; /* Chunk set by the '-1' option */ + int position; /* position in pngtest.png */ + int keep; /* unknown handling setting */ +} chunk_info[] = { + /* Critical chunks */ + { "IDAT", PNG_INFO_IDAT, png_IDAT, 0, 0, START, 0 }, /* must be [0] */ + { "PLTE", PNG_INFO_PLTE, png_PLTE, 0, 0, ABSENT, 0 }, + + /* Non-critical chunks that libpng handles */ + /* This is a mess but it seems to be the only way to do it - there is no way + * to check for a definition outside a #if. + */ + { "bKGD", PNG_INFO_bKGD, png_bKGD, +# ifdef PNG_READ_bKGD_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "cHRM", PNG_INFO_cHRM, png_cHRM, +# ifdef PNG_READ_cHRM_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "gAMA", PNG_INFO_gAMA, png_gAMA, +# ifdef PNG_READ_gAMA_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "hIST", PNG_INFO_hIST, png_hIST, +# ifdef PNG_READ_hIST_SUPPORTED + 0, +# else + 1, +# endif + 1, ABSENT, 0 }, + { "iCCP", PNG_INFO_iCCP, png_iCCP, +# ifdef PNG_READ_iCCP_SUPPORTED + 0, +# else + 1, +# endif + 1, ABSENT, 0 }, + { "iTXt", PNG_INFO_iTXt, png_iTXt, +# ifdef PNG_READ_iTXt_SUPPORTED + 0, +# else + 1, +# endif + 1, ABSENT, 0 }, + { "oFFs", PNG_INFO_oFFs, png_oFFs, +# ifdef PNG_READ_oFFs_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "pCAL", PNG_INFO_pCAL, png_pCAL, +# ifdef PNG_READ_pCAL_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "pHYs", PNG_INFO_pHYs, png_pHYs, +# ifdef PNG_READ_pHYs_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "sBIT", PNG_INFO_sBIT, png_sBIT, +# ifdef PNG_READ_sBIT_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "sCAL", PNG_INFO_sCAL, png_sCAL, +# ifdef PNG_READ_sCAL_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "sPLT", PNG_INFO_sPLT, png_sPLT, +# ifdef PNG_READ_sPLT_SUPPORTED + 0, +# else + 1, +# endif + 1, ABSENT, 0 }, + { "sRGB", PNG_INFO_sRGB, png_sRGB, +# ifdef PNG_READ_sRGB_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "tEXt", PNG_INFO_tEXt, png_tEXt, +# ifdef PNG_READ_tEXt_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "tIME", PNG_INFO_tIME, png_tIME, +# ifdef PNG_READ_tIME_SUPPORTED + 0, +# else + 1, +# endif + 1, START, 0 }, + { "tRNS", PNG_INFO_tRNS, png_tRNS, +# ifdef PNG_READ_tRNS_SUPPORTED + 0, +# else + 1, +# endif + 0, ABSENT, 0 }, + { "zTXt", PNG_INFO_zTXt, png_zTXt, +# ifdef PNG_READ_zTXt_SUPPORTED + 0, +# else + 1, +# endif + 1, END, 0 }, + + /* No libpng handling */ + { "sTER", PNG_INFO_sTER, png_sTER, 1, 1, START, 0 }, + { "vpAg", PNG_INFO_vpAg, png_vpAg, 1, 0, START, 0 }, +}; + +#define NINFO ((int)((sizeof chunk_info)/(sizeof chunk_info[0]))) + +static void +clear_keep(void) +{ + int i = NINFO; + while (--i >= 0) + chunk_info[i].keep = 0; +} + +static int +find(const char *name) +{ + int i = NINFO; + while (--i >= 0) + { + if (memcmp(chunk_info[i].name, name, 4) == 0) + break; + } + + return i; +} + +static int +findb(const png_byte *name) +{ + int i = NINFO; + while (--i >= 0) + { + if (memcmp(chunk_info[i].name, name, 4) == 0) + break; + } + + return i; +} + +static int +find_by_flag(png_uint_32 flag) +{ + int i = NINFO; + + while (--i >= 0) if (chunk_info[i].flag == flag) return i; + + fprintf(stderr, "pngunknown: internal error\n"); + exit(4); +} + +static int +ancillary(const char *name) +{ + return PNG_CHUNK_ANCILLARY(PNG_U32(name[0], name[1], name[2], name[3])); +} + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +static int +ancillaryb(const png_byte *name) +{ + return PNG_CHUNK_ANCILLARY(PNG_U32(name[0], name[1], name[2], name[3])); +} +#endif + +/* Type of an error_ptr */ +typedef struct +{ + jmp_buf error_return; + png_structp png_ptr; + png_infop info_ptr, end_ptr; + png_uint_32 before_IDAT; + png_uint_32 after_IDAT; + int error_count; + int warning_count; + int keep; /* the default value */ + const char *program; + const char *file; + const char *test; +} display; + +static const char init[] = "initialization"; +static const char cmd[] = "command line"; + +static void +init_display(display *d, const char *program) +{ + memset(d, 0, sizeof *d); + d->png_ptr = NULL; + d->info_ptr = d->end_ptr = NULL; + d->error_count = d->warning_count = 0; + d->program = program; + d->file = program; + d->test = init; +} + +static void +clean_display(display *d) +{ + png_destroy_read_struct(&d->png_ptr, &d->info_ptr, &d->end_ptr); + + /* This must not happen - it might cause an app crash */ + if (d->png_ptr != NULL || d->info_ptr != NULL || d->end_ptr != NULL) + { + fprintf(stderr, "%s(%s): png_destroy_read_struct error\n", d->file, + d->test); + exit(1); + } +} + +PNG_FUNCTION(void, display_exit, (display *d), static PNG_NORETURN) +{ + ++(d->error_count); + + if (d->png_ptr != NULL) + clean_display(d); + + /* During initialization and if this is a single command line argument set + * exit now - there is only one test, otherwise longjmp to do the next test. + */ + if (d->test == init || d->test == cmd) + exit(1); + + longjmp(d->error_return, 1); +} + +static int +display_rc(const display *d, int strict) +{ + return d->error_count + (strict ? d->warning_count : 0); +} + +/* libpng error and warning callbacks */ +PNG_FUNCTION(void, (PNGCBAPI error), (png_structp png_ptr, const char *message), + static PNG_NORETURN) +{ + display *d = (display*)png_get_error_ptr(png_ptr); + + fprintf(stderr, "%s(%s): libpng error: %s\n", d->file, d->test, message); + display_exit(d); +} + +static void PNGCBAPI +warning(png_structp png_ptr, const char *message) +{ + display *d = (display*)png_get_error_ptr(png_ptr); + + fprintf(stderr, "%s(%s): libpng warning: %s\n", d->file, d->test, message); + ++(d->warning_count); +} + +static png_uint_32 +get_valid(display *d, png_infop info_ptr) +{ + png_uint_32 flags = png_get_valid(d->png_ptr, info_ptr, (png_uint_32)~0); + + /* Map the text chunks back into the flags */ + { + png_textp text; + png_uint_32 ntext = png_get_text(d->png_ptr, info_ptr, &text, NULL); + + while (ntext-- > 0) switch (text[ntext].compression) + { + case -1: + flags |= PNG_INFO_tEXt; + break; + case 0: + flags |= PNG_INFO_zTXt; + break; + case 1: + case 2: + flags |= PNG_INFO_iTXt; + break; + default: + fprintf(stderr, "%s(%s): unknown text compression %d\n", d->file, + d->test, text[ntext].compression); + display_exit(d); + } + } + + return flags; +} + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED +static int PNGCBAPI +read_callback(png_structp pp, png_unknown_chunkp pc) +{ + /* This function mimics the behavior of png_set_keep_unknown_chunks by + * returning '0' to keep the chunk and '1' to discard it. + */ + display *d = voidcast(display*, png_get_user_chunk_ptr(pp)); + int chunk = findb(pc->name); + int keep, discard; + + if (chunk < 0) /* not one in our list, so not a known chunk */ + keep = d->keep; + + else + { + keep = chunk_info[chunk].keep; + if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT) + { + /* See the comments in png.h - use the default for unknown chunks, + * do not keep known chunks. + */ + if (chunk_info[chunk].unknown) + keep = d->keep; + + else + keep = PNG_HANDLE_CHUNK_NEVER; + } + } + + switch (keep) + { + default: + fprintf(stderr, "%s(%s): %d: unrecognized chunk option\n", d->file, + d->test, chunk_info[chunk].keep); + display_exit(d); + + case PNG_HANDLE_CHUNK_AS_DEFAULT: + case PNG_HANDLE_CHUNK_NEVER: + discard = 1/*handled; discard*/; + break; + + case PNG_HANDLE_CHUNK_IF_SAFE: + case PNG_HANDLE_CHUNK_ALWAYS: + discard = 0/*not handled; keep*/; + break; + } + + /* Also store information about this chunk in the display, the relevant flag + * is set if the chunk is to be kept ('not handled'.) + */ + if (chunk >= 0) if (!discard) /* stupidity to stop a GCC warning */ + { + png_uint_32 flag = chunk_info[chunk].flag; + + if (pc->location & PNG_AFTER_IDAT) + d->after_IDAT |= flag; + + else + d->before_IDAT |= flag; + } + + /* However if there is no support to store unknown chunks don't ask libpng to + * do it; there will be an png_error. + */ +# ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED + return discard; +# else + return 1; /*handled; discard*/ +# endif +} +#endif /* READ_USER_CHUNKS_SUPPORTED */ + +#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED +static png_uint_32 +get_unknown(display *d, png_infop info_ptr, int after_IDAT) +{ + /* Create corresponding 'unknown' flags */ + png_uint_32 flags = 0; + + UNUSED(after_IDAT) + + { + png_unknown_chunkp unknown; + int num_unknown = png_get_unknown_chunks(d->png_ptr, info_ptr, &unknown); + + while (--num_unknown >= 0) + { + int chunk = findb(unknown[num_unknown].name); + + /* Chunks not known to pngunknown must be validated here; since they + * must also be unknown to libpng the 'display->keep' behavior should + * have been used. + */ + if (chunk < 0) switch (d->keep) + { + default: /* impossible */ + case PNG_HANDLE_CHUNK_AS_DEFAULT: + case PNG_HANDLE_CHUNK_NEVER: + fprintf(stderr, "%s(%s): %s: %s: unknown chunk saved\n", + d->file, d->test, d->keep ? "discard" : "default", + unknown[num_unknown].name); + ++(d->error_count); + break; + + case PNG_HANDLE_CHUNK_IF_SAFE: + if (!ancillaryb(unknown[num_unknown].name)) + { + fprintf(stderr, + "%s(%s): if-safe: %s: unknown critical chunk saved\n", + d->file, d->test, unknown[num_unknown].name); + ++(d->error_count); + break; + } + /* FALL THROUGH (safe) */ + case PNG_HANDLE_CHUNK_ALWAYS: + break; + } + + else + flags |= chunk_info[chunk].flag; + } + } + + return flags; +} +#else +static png_uint_32 +get_unknown(display *d, png_infop info_ptr, int after_IDAT) + /* Otherwise this will return the cached values set by any user callback */ +{ + UNUSED(info_ptr); + + if (after_IDAT) + return d->after_IDAT; + + else + return d->before_IDAT; +} + +# ifndef PNG_READ_USER_CHUNKS_SUPPORTED + /* The #defines above should mean this is never reached, it's just here as + * a check to ensure the logic is correct. + */ +# error No store support and no user chunk support, this will not work +# endif +#endif + +static int +check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/, + display *d, int set_callback) +{ + int i, npasses, ipass; + png_uint_32 height; + + d->keep = PNG_HANDLE_CHUNK_AS_DEFAULT; + d->before_IDAT = 0; + d->after_IDAT = 0; + + /* Some of these errors are permanently fatal and cause an exit here, others + * are per-test and cause an error return. + */ + d->png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, d, error, + warning); + if (d->png_ptr == NULL) + { + fprintf(stderr, "%s(%s): could not allocate png struct\n", d->file, + d->test); + /* Terminate here, this error is not test specific. */ + exit(1); + } + + d->info_ptr = png_create_info_struct(d->png_ptr); + d->end_ptr = png_create_info_struct(d->png_ptr); + if (d->info_ptr == NULL || d->end_ptr == NULL) + { + fprintf(stderr, "%s(%s): could not allocate png info\n", d->file, + d->test); + clean_display(d); + exit(1); + } + + png_init_io(d->png_ptr, fp); + +# ifdef PNG_READ_USER_CHUNKS_SUPPORTED + /* This is only done if requested by the caller; it interferes with the + * standard store/save mechanism. + */ + if (set_callback) + png_set_read_user_chunk_fn(d->png_ptr, d, read_callback); +# else + UNUSED(set_callback) +# endif + + /* Handle each argument in turn; multiple settings are possible for the same + * chunk and multiple calls will occur (the last one should override all + * preceding ones). + */ + for (i=0; i<argc; ++i) + { + const char *equals = strchr(argv[i], '='); + + if (equals != NULL) + { + int chunk, option; + + if (strcmp(equals+1, "default") == 0) + option = PNG_HANDLE_CHUNK_AS_DEFAULT; + else if (strcmp(equals+1, "discard") == 0) + option = PNG_HANDLE_CHUNK_NEVER; + else if (strcmp(equals+1, "if-safe") == 0) + option = PNG_HANDLE_CHUNK_IF_SAFE; + else if (strcmp(equals+1, "save") == 0) + option = PNG_HANDLE_CHUNK_ALWAYS; + else + { + fprintf(stderr, "%s(%s): %s: unrecognized chunk option\n", d->file, + d->test, argv[i]); + display_exit(d); + } + + switch (equals - argv[i]) + { + case 4: /* chunk name */ + chunk = find(argv[i]); + + if (chunk >= 0) + { + /* These #if tests have the effect of skipping the arguments + * if SAVE support is unavailable - we can't do a useful test + * in this case, so we just check the arguments! This could + * be improved in the future by using the read callback. + */ + png_byte name[5]; + + memcpy(name, chunk_info[chunk].name, 5); + png_set_keep_unknown_chunks(d->png_ptr, option, name, 1); + chunk_info[chunk].keep = option; + continue; + } + + break; + + case 7: /* default */ + if (memcmp(argv[i], "default", 7) == 0) + { + png_set_keep_unknown_chunks(d->png_ptr, option, NULL, 0); + d->keep = option; + continue; + } + + break; + + case 3: /* all */ + if (memcmp(argv[i], "all", 3) == 0) + { + png_set_keep_unknown_chunks(d->png_ptr, option, NULL, -1); + d->keep = option; + + for (chunk = 0; chunk < NINFO; ++chunk) + if (chunk_info[chunk].all) + chunk_info[chunk].keep = option; + continue; + } + + break; + + default: /* some misplaced = */ + + break; + } + } + + fprintf(stderr, "%s(%s): %s: unrecognized chunk argument\n", d->file, + d->test, argv[i]); + display_exit(d); + } + + png_read_info(d->png_ptr, d->info_ptr); + + switch (png_get_interlace_type(d->png_ptr, d->info_ptr)) + { + case PNG_INTERLACE_NONE: + npasses = 1; + break; + + case PNG_INTERLACE_ADAM7: + npasses = PNG_INTERLACE_ADAM7_PASSES; + break; + + default: + /* Hard error because it is not test specific */ + fprintf(stderr, "%s(%s): invalid interlace type\n", d->file, d->test); + clean_display(d); + exit(1); + } + + /* Skip the image data, if IDAT is not being handled then don't do this + * because it will cause a CRC error. + */ + if (chunk_info[0/*IDAT*/].keep == PNG_HANDLE_CHUNK_AS_DEFAULT) + { + png_start_read_image(d->png_ptr); + height = png_get_image_height(d->png_ptr, d->info_ptr); + + if (npasses > 1) + { + png_uint_32 width = png_get_image_width(d->png_ptr, d->info_ptr); + + for (ipass=0; ipass<npasses; ++ipass) + { + png_uint_32 wPass = PNG_PASS_COLS(width, ipass); + + if (wPass > 0) + { + png_uint_32 y; + + for (y=0; y<height; ++y) if (PNG_ROW_IN_INTERLACE_PASS(y, ipass)) + png_read_row(d->png_ptr, NULL, NULL); + } + } + } /* interlaced */ + + else /* not interlaced */ + { + png_uint_32 y; + + for (y=0; y<height; ++y) + png_read_row(d->png_ptr, NULL, NULL); + } + } + + png_read_end(d->png_ptr, d->end_ptr); + + flags[0] = get_valid(d, d->info_ptr); + flags[1] = get_unknown(d, d->info_ptr, 0/*before IDAT*/); + + /* Only png_read_png sets PNG_INFO_IDAT! */ + flags[chunk_info[0/*IDAT*/].keep != PNG_HANDLE_CHUNK_AS_DEFAULT] |= + PNG_INFO_IDAT; + + flags[2] = get_valid(d, d->end_ptr); + flags[3] = get_unknown(d, d->end_ptr, 1/*after IDAT*/); + + clean_display(d); + + return d->keep; +} + +static void +check_error(display *d, png_uint_32 flags, const char *message) +{ + while (flags) + { + png_uint_32 flag = flags & -(png_int_32)flags; + int i = find_by_flag(flag); + + fprintf(stderr, "%s(%s): chunk %s: %s\n", d->file, d->test, + chunk_info[i].name, message); + ++(d->error_count); + + flags &= ~flag; + } +} + +static void +check_handling(display *d, int def, png_uint_32 chunks, png_uint_32 known, + png_uint_32 unknown, const char *position, int set_callback) +{ + while (chunks) + { + png_uint_32 flag = chunks & -(png_int_32)chunks; + int i = find_by_flag(flag); + int keep = chunk_info[i].keep; + const char *type; + const char *errorx = NULL; + + if (chunk_info[i].unknown) + { + if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT) + { + type = "UNKNOWN (default)"; + keep = def; + } + + else + type = "UNKNOWN (specified)"; + + if (flag & known) + errorx = "chunk processed"; + + else switch (keep) + { + case PNG_HANDLE_CHUNK_AS_DEFAULT: + if (flag & unknown) + errorx = "DEFAULT: unknown chunk saved"; + break; + + case PNG_HANDLE_CHUNK_NEVER: + if (flag & unknown) + errorx = "DISCARD: unknown chunk saved"; + break; + + case PNG_HANDLE_CHUNK_IF_SAFE: + if (ancillary(chunk_info[i].name)) + { + if (!(flag & unknown)) + errorx = "IF-SAFE: unknown ancillary chunk lost"; + } + + else if (flag & unknown) + errorx = "IF-SAFE: unknown critical chunk saved"; + break; + + case PNG_HANDLE_CHUNK_ALWAYS: + if (!(flag & unknown)) + errorx = "SAVE: unknown chunk lost"; + break; + + default: + errorx = "internal error: bad keep"; + break; + } + } /* unknown chunk */ + + else /* known chunk */ + { + type = "KNOWN"; + + if (flag & known) + { + /* chunk was processed, it won't have been saved because that is + * caught below when checking for inconsistent processing. + */ + if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT) + errorx = "!DEFAULT: known chunk processed"; + } + + else /* not processed */ switch (keep) + { + case PNG_HANDLE_CHUNK_AS_DEFAULT: + errorx = "DEFAULT: known chunk not processed"; + break; + + case PNG_HANDLE_CHUNK_NEVER: + if (flag & unknown) + errorx = "DISCARD: known chunk saved"; + break; + + case PNG_HANDLE_CHUNK_IF_SAFE: + if (ancillary(chunk_info[i].name)) + { + if (!(flag & unknown)) + errorx = "IF-SAFE: known ancillary chunk lost"; + } + + else if (flag & unknown) + errorx = "IF-SAFE: known critical chunk saved"; + break; + + case PNG_HANDLE_CHUNK_ALWAYS: + if (!(flag & unknown)) + errorx = "SAVE: known chunk lost"; + break; + + default: + errorx = "internal error: bad keep (2)"; + break; + } + } + + if (errorx != NULL) + { + ++(d->error_count); + fprintf(stderr, "%s(%s%s): %s %s %s: %s\n", d->file, d->test, + set_callback ? ",callback" : "", + type, chunk_info[i].name, position, errorx); + } + + chunks &= ~flag; + } +} + +static void +perform_one_test(FILE *fp, int argc, const char **argv, + png_uint_32 *default_flags, display *d, int set_callback) +{ + int def; + png_uint_32 flags[2][4]; + + rewind(fp); + clear_keep(); + memcpy(flags[0], default_flags, sizeof flags[0]); + + def = check(fp, argc, argv, flags[1], d, set_callback); + + /* Chunks should either be known or unknown, never both and this should apply + * whether the chunk is before or after the IDAT (actually, the app can + * probably change this by swapping the handling after the image, but this + * test does not do that.) + */ + check_error(d, (flags[0][0]|flags[0][2]) & (flags[0][1]|flags[0][3]), + "chunk handled inconsistently in count tests"); + check_error(d, (flags[1][0]|flags[1][2]) & (flags[1][1]|flags[1][3]), + "chunk handled inconsistently in option tests"); + + /* Now find out what happened to each chunk before and after the IDAT and + * determine if the behavior was correct. First some basic sanity checks, + * any known chunk should be known in the original count, any unknown chunk + * should be either known or unknown in the original. + */ + { + png_uint_32 test; + + test = flags[1][0] & ~flags[0][0]; + check_error(d, test, "new known chunk before IDAT"); + test = flags[1][1] & ~(flags[0][0] | flags[0][1]); + check_error(d, test, "new unknown chunk before IDAT"); + test = flags[1][2] & ~flags[0][2]; + check_error(d, test, "new known chunk after IDAT"); + test = flags[1][3] & ~(flags[0][2] | flags[0][3]); + check_error(d, test, "new unknown chunk after IDAT"); + } + + /* Now each chunk in the original list should have been handled according to + * the options set for that chunk, regardless of whether libpng knows about + * it or not. + */ + check_handling(d, def, flags[0][0] | flags[0][1], flags[1][0], flags[1][1], + "before IDAT", set_callback); + check_handling(d, def, flags[0][2] | flags[0][3], flags[1][2], flags[1][3], + "after IDAT", set_callback); +} + +static void +perform_one_test_safe(FILE *fp, int argc, const char **argv, + png_uint_32 *default_flags, display *d, const char *test) +{ + if (setjmp(d->error_return) == 0) + { + d->test = test; /* allow use of d->error_return */ +# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED + perform_one_test(fp, argc, argv, default_flags, d, 0); +# endif +# ifdef PNG_READ_USER_CHUNKS_SUPPORTED + perform_one_test(fp, argc, argv, default_flags, d, 1); +# endif + d->test = init; /* prevent use of d->error_return */ + } +} + +static const char *standard_tests[] = +{ + "discard", "default=discard", 0, + "save", "default=save", 0, + "if-safe", "default=if-safe", 0, + "vpAg", "vpAg=if-safe", 0, + "sTER", "sTER=if-safe", 0, + "IDAT", "default=discard", "IDAT=save", 0, + "sAPI", "bKGD=save", "cHRM=save", "gAMA=save", "all=discard", "iCCP=save", + "sBIT=save", "sRGB=save", 0, + 0/*end*/ +}; + +static PNG_NORETURN void +usage(const char *program, const char *reason) +{ + fprintf(stderr, "pngunknown: %s: usage:\n %s [--strict] " + "--default|{(CHNK|default|all)=(default|discard|if-safe|save)} " + "testfile.png\n", reason, program); + exit(99); +} + +int +main(int argc, const char **argv) +{ + FILE *fp; + png_uint_32 default_flags[4/*valid,unknown{before,after}*/]; + int strict = 0, default_tests = 0; + const char *count_argv = "default=save"; + const char *touch_file = NULL; + display d; + + init_display(&d, argv[0]); + + while (++argv, --argc > 0) + { + if (strcmp(*argv, "--strict") == 0) + strict = 1; + + else if (strcmp(*argv, "--default") == 0) + default_tests = 1; + + else if (strcmp(*argv, "--touch") == 0) + { + if (argc > 1) + touch_file = *++argv, --argc; + + else + usage(d.program, "--touch: missing file name"); + } + + else + break; + } + + /* A file name is required, but there should be no other arguments if + * --default was specified. + */ + if (argc <= 0) + usage(d.program, "missing test file"); + + /* GCC BUG: if (default_tests && argc != 1) triggers some weird GCC argc + * optimization which causes warnings with -Wstrict-overflow! + */ + else if (default_tests) if (argc != 1) + usage(d.program, "extra arguments"); + + /* The name of the test file is the last argument; remove it. */ + d.file = argv[--argc]; + + fp = fopen(d.file, "rb"); + if (fp == NULL) + { + perror(d.file); + exit(99); + } + + /* First find all the chunks, known and unknown, in the test file, a failure + * here aborts the whole test. + * + * If 'save' is supported then the normal saving method should happen, + * otherwise if 'read' is supported then the read callback will do the + * same thing. If both are supported the 'read' callback won't be + * instantiated by default. If 'save' is *not* supported then a user + * callback is required even though we can call png_get_unknown_chunks. + */ + if (check(fp, 1, &count_argv, default_flags, &d, +# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED + 0 +# else + 1 +# endif + ) != PNG_HANDLE_CHUNK_ALWAYS) + { + fprintf(stderr, "%s: %s: internal error\n", d.program, d.file); + exit(99); + } + + /* Now find what the various supplied options cause to change: */ + if (!default_tests) + { + d.test = cmd; /* acts as a flag to say exit, do not longjmp */ +# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED + perform_one_test(fp, argc, argv, default_flags, &d, 0); +# endif +# ifdef PNG_READ_USER_CHUNKS_SUPPORTED + perform_one_test(fp, argc, argv, default_flags, &d, 1); +# endif + d.test = init; + } + + else + { + const char **test = standard_tests; + + /* Set the exit_test pointer here so we can continue after a libpng error. + * NOTE: this leaks memory because the png_struct data from the failing + * test is never freed. + */ + while (*test) + { + const char *this_test = *test++; + const char **next = test; + int count = display_rc(&d, strict), new_count; + const char *result; + int arg_count = 0; + + while (*next) ++next, ++arg_count; + + perform_one_test_safe(fp, arg_count, test, default_flags, &d, + this_test); + + new_count = display_rc(&d, strict); + + if (new_count == count) + result = "PASS"; + + else + result = "FAIL"; + + printf("%s: %s %s\n", result, d.program, this_test); + + test = next+1; + } + } + + fclose(fp); + + if (display_rc(&d, strict) == 0) + { + /* Success, touch the success file if appropriate */ + if (touch_file != NULL) + { + FILE *fsuccess = fopen(touch_file, "wt"); + + if (fsuccess != NULL) + { + int err = 0; + fprintf(fsuccess, "PNG unknown tests succeeded\n"); + fflush(fsuccess); + err = ferror(fsuccess); + + if (fclose(fsuccess) || err) + { + fprintf(stderr, "%s: write failed\n", touch_file); + exit(99); + } + } + + else + { + fprintf(stderr, "%s: open failed\n", touch_file); + exit(99); + } + } + + return 0; + } + + return 1; +} + +#else /* !(READ_USER_CHUNKS || SAVE_UNKNOWN_CHUNKS) */ +int +main(void) +{ + fprintf(stderr, + " test ignored: no support to find out about unknown chunks\n"); + /* So the test is skipped: */ + return 77; +} +#endif /* READ_USER_CHUNKS || SAVE_UNKNOWN_CHUNKS */ + +#else /* !(SET_UNKNOWN_CHUNKS && READ) */ +int +main(void) +{ + fprintf(stderr, + " test ignored: no support to modify unknown chunk handling\n"); + /* So the test is skipped: */ + return 77; +} +#endif /* SET_UNKNOWN_CHUNKS && READ */ diff --git a/libpng/contrib/libtests/pngvalid.c b/libpng/contrib/libtests/pngvalid.c new file mode 100644 index 000000000..79de125da --- /dev/null +++ b/libpng/contrib/libtests/pngvalid.c @@ -0,0 +1,11238 @@ + +/* pngvalid.c - validate libpng by constructing then reading png files. + * + * Last changed in libpng 1.6.17 [March 26, 2015] + * Copyright (c) 2014-2015 Glenn Randers-Pehrson + * Written by John Cunningham Bowler + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * NOTES: + * This is a C program that is intended to be linked against libpng. It + * generates bitmaps internally, stores them as PNG files (using the + * sequential write code) then reads them back (using the sequential + * read code) and validates that the result has the correct data. + * + * The program can be modified and extended to test the correctness of + * transformations performed by libpng. + */ + +#define _POSIX_SOURCE 1 +#define _ISOC99_SOURCE 1 /* For floating point */ +#define _GNU_SOURCE 1 /* For the floating point exception extension */ + +#include <signal.h> +#include <stdio.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +#ifdef HAVE_FEENABLEEXCEPT /* from config.h, if included */ +# include <fenv.h> +#endif + +#ifndef FE_DIVBYZERO +# define FE_DIVBYZERO 0 +#endif +#ifndef FE_INVALID +# define FE_INVALID 0 +#endif +#ifndef FE_OVERFLOW +# define FE_OVERFLOW 0 +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +#ifdef PNG_ZLIB_HEADER +# include PNG_ZLIB_HEADER +#else +# include <zlib.h> /* For crc32 */ +#endif + +/* 1.6.1 added support for the configure test harness, which uses 77 to indicate + * a skipped test, in earlier versions we need to succeed on a skipped test, so: + */ +#if PNG_LIBPNG_VER < 10601 +# define SKIP 0 +#else +# define SKIP 77 +#endif + +/* pngvalid requires write support and one of the fixed or floating point APIs. + */ +#if defined(PNG_WRITE_SUPPORTED) &&\ + (defined(PNG_FIXED_POINT_SUPPORTED) || defined(PNG_FLOATING_POINT_SUPPORTED)) + +#if PNG_LIBPNG_VER < 10500 +/* This deliberately lacks the PNG_CONST. */ +typedef png_byte *png_const_bytep; + +/* This is copied from 1.5.1 png.h: */ +#define PNG_INTERLACE_ADAM7_PASSES 7 +#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ + -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ + -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) +#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ + (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) +#define PNG_COL_FROM_PASS_COL(xIn, pass) \ + (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) +#define PNG_PASS_MASK(pass,off) ( \ + ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \ + ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +/* These are needed too for the default build: */ +#define PNG_WRITE_16BIT_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED + +/* This comes from pnglibconf.h afer 1.5: */ +#define PNG_FP_1 100000 +#define PNG_GAMMA_THRESHOLD_FIXED\ + ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1)) +#endif + +#if PNG_LIBPNG_VER < 10600 + /* 1.6.0 constifies many APIs, the following exists to allow pngvalid to be + * compiled against earlier versions. + */ +# define png_const_structp png_structp +#endif + +#include <float.h> /* For floating point constants */ +#include <stdlib.h> /* For malloc */ +#include <string.h> /* For memcpy, memset */ +#include <math.h> /* For floor */ + +/* Unused formal parameter errors are removed using the following macro which is + * expected to have no bad effects on performance. + */ +#ifndef UNUSED +# if defined(__GNUC__) || defined(_MSC_VER) +# define UNUSED(param) (void)param; +# else +# define UNUSED(param) +# endif +#endif + +/***************************** EXCEPTION HANDLING *****************************/ +#ifdef PNG_FREESTANDING_TESTS +# include <cexcept.h> +#else +# include "../visupng/cexcept.h" +#endif + +#ifdef __cplusplus +# define this not_the_cpp_this +# define new not_the_cpp_new +# define voidcast(type, value) static_cast<type>(value) +#else +# define voidcast(type, value) (value) +#endif /* __cplusplus */ + +struct png_store; +define_exception_type(struct png_store*); + +/* The following are macros to reduce typing everywhere where the well known + * name 'the_exception_context' must be defined. + */ +#define anon_context(ps) struct exception_context *the_exception_context = \ + &(ps)->exception_context +#define context(ps,fault) anon_context(ps); png_store *fault + +/* This macro returns the number of elements in an array as an (unsigned int), + * it is necessary to avoid the inability of certain versions of GCC to use + * the value of a compile-time constant when performing range checks. It must + * be passed an array name. + */ +#define ARRAY_SIZE(a) ((unsigned int)((sizeof (a))/(sizeof (a)[0]))) + +/******************************* UTILITIES ************************************/ +/* Error handling is particularly problematic in production code - error + * handlers often themselves have bugs which lead to programs that detect + * minor errors crashing. The following functions deal with one very + * common class of errors in error handlers - attempting to format error or + * warning messages into buffers that are too small. + */ +static size_t safecat(char *buffer, size_t bufsize, size_t pos, + PNG_CONST char *cat) +{ + while (pos < bufsize && cat != NULL && *cat != 0) + buffer[pos++] = *cat++; + + if (pos >= bufsize) + pos = bufsize-1; + + buffer[pos] = 0; + return pos; +} + +static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n) +{ + char number[64]; + sprintf(number, "%d", n); + return safecat(buffer, bufsize, pos, number); +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d, + int precision) +{ + char number[64]; + sprintf(number, "%.*f", precision, d); + return safecat(buffer, bufsize, pos, number); +} +#endif + +static PNG_CONST char invalid[] = "invalid"; +static PNG_CONST char sep[] = ": "; + +static PNG_CONST char *colour_types[8] = +{ + "grayscale", invalid, "truecolour", "indexed-colour", + "grayscale with alpha", invalid, "truecolour with alpha", invalid +}; + +#ifdef PNG_READ_SUPPORTED +/* Convert a double precision value to fixed point. */ +static png_fixed_point +fix(double d) +{ + d = floor(d * PNG_FP_1 + .5); + return (png_fixed_point)d; +} +#endif /* PNG_READ_SUPPORTED */ + +/* Generate random bytes. This uses a boring repeatable algorithm and it + * is implemented here so that it gives the same set of numbers on every + * architecture. It's a linear congruential generator (Knuth or Sedgewick + * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and + * Hill, "The Art of Electronics" (Pseudo-Random Bit Sequences and Noise + * Generation.) + */ +static void +make_random_bytes(png_uint_32* seed, void* pv, size_t size) +{ + png_uint_32 u0 = seed[0], u1 = seed[1]; + png_bytep bytes = voidcast(png_bytep, pv); + + /* There are thirty three bits, the next bit in the sequence is bit-33 XOR + * bit-20. The top 1 bit is in u1, the bottom 32 are in u0. + */ + size_t i; + for (i=0; i<size; ++i) + { + /* First generate 8 new bits then shift them in at the end. */ + png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; + u1 <<= 8; + u1 |= u0 >> 24; + u0 <<= 8; + u0 |= u; + *bytes++ = (png_byte)u; + } + + seed[0] = u0; + seed[1] = u1; +} + +static void +make_four_random_bytes(png_uint_32* seed, png_bytep bytes) +{ + make_random_bytes(seed, bytes, 4); +} + +#ifdef PNG_READ_SUPPORTED +static void +randomize(void *pv, size_t size) +{ + static png_uint_32 random_seed[2] = {0x56789abc, 0xd}; + make_random_bytes(random_seed, pv, size); +} + +#define RANDOMIZE(this) randomize(&(this), sizeof (this)) + +static unsigned int +random_mod(unsigned int max) +{ + unsigned int x; + + RANDOMIZE(x); + + return x % max; /* 0 .. max-1 */ +} + +#if (defined PNG_READ_RGB_TO_GRAY_SUPPORTED) ||\ + (defined PNG_READ_FILLER_SUPPORTED) +static int +random_choice(void) +{ + unsigned char x; + + RANDOMIZE(x); + + return x & 1; +} +#endif +#endif /* PNG_READ_SUPPORTED */ + +/* A numeric ID based on PNG file characteristics. The 'do_interlace' field + * simply records whether pngvalid did the interlace itself or whether it + * was done by libpng. Width and height must be less than 256. 'palette' is an + * index of the palette to use for formats with a palette (0 otherwise.) + */ +#define FILEID(col, depth, palette, interlace, width, height, do_interlace) \ + ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \ + (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24))) + +#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U)) +#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU)) +#define PALETTE_FROM_ID(id) (((id) >> 8) & 0x1f) +#define INTERLACE_FROM_ID(id) ((png_byte)(((id) >> 13) & 0x3)) +#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1)) +#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff) +#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff) + +/* Utility to construct a standard name for a standard image. */ +static size_t +standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type, + int bit_depth, unsigned int npalette, int interlace_type, + png_uint_32 w, png_uint_32 h, int do_interlace) +{ + pos = safecat(buffer, bufsize, pos, colour_types[colour_type]); + if (npalette > 0) + { + pos = safecat(buffer, bufsize, pos, "["); + pos = safecatn(buffer, bufsize, pos, npalette); + pos = safecat(buffer, bufsize, pos, "]"); + } + pos = safecat(buffer, bufsize, pos, " "); + pos = safecatn(buffer, bufsize, pos, bit_depth); + pos = safecat(buffer, bufsize, pos, " bit"); + + if (interlace_type != PNG_INTERLACE_NONE) + { + pos = safecat(buffer, bufsize, pos, " interlaced"); + if (do_interlace) + pos = safecat(buffer, bufsize, pos, "(pngvalid)"); + else + pos = safecat(buffer, bufsize, pos, "(libpng)"); + } + + if (w > 0 || h > 0) + { + pos = safecat(buffer, bufsize, pos, " "); + pos = safecatn(buffer, bufsize, pos, w); + pos = safecat(buffer, bufsize, pos, "x"); + pos = safecatn(buffer, bufsize, pos, h); + } + + return pos; +} + +static size_t +standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id) +{ + return standard_name(buffer, bufsize, pos, COL_FROM_ID(id), + DEPTH_FROM_ID(id), PALETTE_FROM_ID(id), INTERLACE_FROM_ID(id), + WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id)); +} + +/* Convenience API and defines to list valid formats. Note that 16 bit read and + * write support is required to do 16 bit read tests (we must be able to make a + * 16 bit image to test!) + */ +#ifdef PNG_WRITE_16BIT_SUPPORTED +# define WRITE_BDHI 4 +# ifdef PNG_READ_16BIT_SUPPORTED +# define READ_BDHI 4 +# define DO_16BIT +# endif +#else +# define WRITE_BDHI 3 +#endif +#ifndef DO_16BIT +# define READ_BDHI 3 +#endif + +/* The following defines the number of different palettes to generate for + * each log bit depth of a colour type 3 standard image. + */ +#define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1U : 16U) + +static int +next_format(png_bytep colour_type, png_bytep bit_depth, + unsigned int* palette_number, int no_low_depth_gray) +{ + if (*bit_depth == 0) + { + *colour_type = 0; + if (no_low_depth_gray) + *bit_depth = 8; + else + *bit_depth = 1; + *palette_number = 0; + return 1; + } + + if (*colour_type == 3) + { + /* Add multiple palettes for colour type 3. */ + if (++*palette_number < PALETTE_COUNT(*bit_depth)) + return 1; + + *palette_number = 0; + } + + *bit_depth = (png_byte)(*bit_depth << 1); + + /* Palette images are restricted to 8 bit depth */ + if (*bit_depth <= 8 +#ifdef DO_16BIT + || (*colour_type != 3 && *bit_depth <= 16) +#endif + ) + return 1; + + /* Move to the next color type, or return 0 at the end. */ + switch (*colour_type) + { + case 0: + *colour_type = 2; + *bit_depth = 8; + return 1; + + case 2: + *colour_type = 3; + *bit_depth = 1; + return 1; + + case 3: + *colour_type = 4; + *bit_depth = 8; + return 1; + + case 4: + *colour_type = 6; + *bit_depth = 8; + return 1; + + default: + return 0; + } +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +static unsigned int +sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth, + png_uint_32 x, unsigned int sample_index, int swap16, int littleendian) +{ + png_uint_32 bit_index, result; + + /* Find a sample index for the desired sample: */ + x *= bit_depth; + bit_index = x; + + if ((colour_type & 1) == 0) /* !palette */ + { + if (colour_type & 2) + bit_index *= 3; + + if (colour_type & 4) + bit_index += x; /* Alpha channel */ + + /* Multiple channels; select one: */ + if (colour_type & (2+4)) + bit_index += sample_index * bit_depth; + } + + /* Return the sample from the row as an integer. */ + row += bit_index >> 3; + result = *row; + + if (bit_depth == 8) + return result; + + else if (bit_depth > 8) + { + if (swap16) + return (*++row << 8) + result; + else + return (result << 8) + *++row; + } + + /* Less than 8 bits per sample. By default PNG has the big end of + * the egg on the left of the screen, but if littleendian is set + * then the big end is on the right. + */ + bit_index &= 7; + + if (!littleendian) + bit_index = 8-bit_index-bit_depth; + + return (result >> bit_index) & ((1U<<bit_depth)-1); +} +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +/* Copy a single pixel, of a given size, from one buffer to another - + * while this is basically bit addressed there is an implicit assumption + * that pixels 8 or more bits in size are byte aligned and that pixels + * do not otherwise cross byte boundaries. (This is, so far as I know, + * universally true in bitmap computer graphics. [JCB 20101212]) + * + * NOTE: The to and from buffers may be the same. + */ +static void +pixel_copy(png_bytep toBuffer, png_uint_32 toIndex, + png_const_bytep fromBuffer, png_uint_32 fromIndex, unsigned int pixelSize) +{ + /* Assume we can multiply by 'size' without overflow because we are + * just working in a single buffer. + */ + toIndex *= pixelSize; + fromIndex *= pixelSize; + if (pixelSize < 8) /* Sub-byte */ + { + /* Mask to select the location of the copied pixel: */ + unsigned int destMask = ((1U<<pixelSize)-1) << (8-pixelSize-(toIndex&7)); + /* The following read the entire pixels and clears the extra: */ + unsigned int destByte = toBuffer[toIndex >> 3] & ~destMask; + unsigned int sourceByte = fromBuffer[fromIndex >> 3]; + + /* Don't rely on << or >> supporting '0' here, just in case: */ + fromIndex &= 7; + if (fromIndex > 0) sourceByte <<= fromIndex; + if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7; + + toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask)); + } + else /* One or more bytes */ + memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3); +} + +#ifdef PNG_READ_SUPPORTED +/* Copy a complete row of pixels, taking into account potential partial + * bytes at the end. + */ +static void +row_copy(png_bytep toBuffer, png_const_bytep fromBuffer, unsigned int bitWidth) +{ + memcpy(toBuffer, fromBuffer, bitWidth >> 3); + + if ((bitWidth & 7) != 0) + { + unsigned int mask; + + toBuffer += bitWidth >> 3; + fromBuffer += bitWidth >> 3; + /* The remaining bits are in the top of the byte, the mask is the bits to + * retain. + */ + mask = 0xff >> (bitWidth & 7); + *toBuffer = (png_byte)((*toBuffer & mask) | (*fromBuffer & ~mask)); + } +} + +/* Compare pixels - they are assumed to start at the first byte in the + * given buffers. + */ +static int +pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width) +{ +#if PNG_LIBPNG_VER < 10506 + if (memcmp(pa, pb, bit_width>>3) == 0) + { + png_uint_32 p; + + if ((bit_width & 7) == 0) return 0; + + /* Ok, any differences? */ + p = pa[bit_width >> 3]; + p ^= pb[bit_width >> 3]; + + if (p == 0) return 0; + + /* There are, but they may not be significant, remove the bits + * after the end (the low order bits in PNG.) + */ + bit_width &= 7; + p >>= 8-bit_width; + + if (p == 0) return 0; + } +#else + /* From libpng-1.5.6 the overwrite should be fixed, so compare the trailing + * bits too: + */ + if (memcmp(pa, pb, (bit_width+7)>>3) == 0) + return 0; +#endif + + /* Return the index of the changed byte. */ + { + png_uint_32 where = 0; + + while (pa[where] == pb[where]) ++where; + return 1+where; + } +} +#endif /* PNG_READ_SUPPORTED */ + +/*************************** BASIC PNG FILE WRITING ***************************/ +/* A png_store takes data from the sequential writer or provides data + * to the sequential reader. It can also store the result of a PNG + * write for later retrieval. + */ +#define STORE_BUFFER_SIZE 500 /* arbitrary */ +typedef struct png_store_buffer +{ + struct png_store_buffer* prev; /* NOTE: stored in reverse order */ + png_byte buffer[STORE_BUFFER_SIZE]; +} png_store_buffer; + +#define FILE_NAME_SIZE 64 + +typedef struct store_palette_entry /* record of a single palette entry */ +{ + png_byte red; + png_byte green; + png_byte blue; + png_byte alpha; +} store_palette_entry, store_palette[256]; + +typedef struct png_store_file +{ + struct png_store_file* next; /* as many as you like... */ + char name[FILE_NAME_SIZE]; + png_uint_32 id; /* must be correct (see FILEID) */ + png_size_t datacount; /* In this (the last) buffer */ + png_store_buffer data; /* Last buffer in file */ + int npalette; /* Number of entries in palette */ + store_palette_entry* palette; /* May be NULL */ +} png_store_file; + +/* The following is a pool of memory allocated by a single libpng read or write + * operation. + */ +typedef struct store_pool +{ + struct png_store *store; /* Back pointer */ + struct store_memory *list; /* List of allocated memory */ + png_byte mark[4]; /* Before and after data */ + + /* Statistics for this run. */ + png_alloc_size_t max; /* Maximum single allocation */ + png_alloc_size_t current; /* Current allocation */ + png_alloc_size_t limit; /* Highest current allocation */ + png_alloc_size_t total; /* Total allocation */ + + /* Overall statistics (retained across successive runs). */ + png_alloc_size_t max_max; + png_alloc_size_t max_limit; + png_alloc_size_t max_total; +} store_pool; + +typedef struct png_store +{ + /* For cexcept.h exception handling - simply store one of these; + * the context is a self pointer but it may point to a different + * png_store (in fact it never does in this program.) + */ + struct exception_context + exception_context; + + unsigned int verbose :1; + unsigned int treat_warnings_as_errors :1; + unsigned int expect_error :1; + unsigned int expect_warning :1; + unsigned int saw_warning :1; + unsigned int speed :1; + unsigned int progressive :1; /* use progressive read */ + unsigned int validated :1; /* used as a temporary flag */ + int nerrors; + int nwarnings; + int noptions; /* number of options below: */ + struct { + unsigned char option; /* option number, 0..30 */ + unsigned char setting; /* setting (unset,invalid,on,off) */ + } options[16]; + char test[128]; /* Name of test */ + char error[256]; + + /* Read fields */ + png_structp pread; /* Used to read a saved file */ + png_infop piread; + png_store_file* current; /* Set when reading */ + png_store_buffer* next; /* Set when reading */ + png_size_t readpos; /* Position in *next */ + png_byte* image; /* Buffer for reading interlaced images */ + png_size_t cb_image; /* Size of this buffer */ + png_size_t cb_row; /* Row size of the image(s) */ + png_uint_32 image_h; /* Number of rows in a single image */ + store_pool read_memory_pool; + + /* Write fields */ + png_store_file* saved; + png_structp pwrite; /* Used when writing a new file */ + png_infop piwrite; + png_size_t writepos; /* Position in .new */ + char wname[FILE_NAME_SIZE]; + png_store_buffer new; /* The end of the new PNG file being written. */ + store_pool write_memory_pool; + store_palette_entry* palette; + int npalette; +} png_store; + +/* Initialization and cleanup */ +static void +store_pool_mark(png_bytep mark) +{ + static png_uint_32 store_seed[2] = { 0x12345678, 1}; + + make_four_random_bytes(store_seed, mark); +} + +#ifdef PNG_READ_SUPPORTED +/* Use this for random 32 bit values; this function makes sure the result is + * non-zero. + */ +static png_uint_32 +random_32(void) +{ + + for (;;) + { + png_byte mark[4]; + png_uint_32 result; + + store_pool_mark(mark); + result = png_get_uint_32(mark); + + if (result != 0) + return result; + } +} +#endif /* PNG_READ_SUPPORTED */ + +static void +store_pool_init(png_store *ps, store_pool *pool) +{ + memset(pool, 0, sizeof *pool); + + pool->store = ps; + pool->list = NULL; + pool->max = pool->current = pool->limit = pool->total = 0; + pool->max_max = pool->max_limit = pool->max_total = 0; + store_pool_mark(pool->mark); +} + +static void +store_init(png_store* ps) +{ + memset(ps, 0, sizeof *ps); + init_exception_context(&ps->exception_context); + store_pool_init(ps, &ps->read_memory_pool); + store_pool_init(ps, &ps->write_memory_pool); + ps->verbose = 0; + ps->treat_warnings_as_errors = 0; + ps->expect_error = 0; + ps->expect_warning = 0; + ps->saw_warning = 0; + ps->speed = 0; + ps->progressive = 0; + ps->validated = 0; + ps->nerrors = ps->nwarnings = 0; + ps->pread = NULL; + ps->piread = NULL; + ps->saved = ps->current = NULL; + ps->next = NULL; + ps->readpos = 0; + ps->image = NULL; + ps->cb_image = 0; + ps->cb_row = 0; + ps->image_h = 0; + ps->pwrite = NULL; + ps->piwrite = NULL; + ps->writepos = 0; + ps->new.prev = NULL; + ps->palette = NULL; + ps->npalette = 0; + ps->noptions = 0; +} + +static void +store_freebuffer(png_store_buffer* psb) +{ + if (psb->prev) + { + store_freebuffer(psb->prev); + free(psb->prev); + psb->prev = NULL; + } +} + +static void +store_freenew(png_store *ps) +{ + store_freebuffer(&ps->new); + ps->writepos = 0; + if (ps->palette != NULL) + { + free(ps->palette); + ps->palette = NULL; + ps->npalette = 0; + } +} + +static void +store_storenew(png_store *ps) +{ + png_store_buffer *pb; + + if (ps->writepos != STORE_BUFFER_SIZE) + png_error(ps->pwrite, "invalid store call"); + + pb = voidcast(png_store_buffer*, malloc(sizeof *pb)); + + if (pb == NULL) + png_error(ps->pwrite, "store new: OOM"); + + *pb = ps->new; + ps->new.prev = pb; + ps->writepos = 0; +} + +static void +store_freefile(png_store_file **ppf) +{ + if (*ppf != NULL) + { + store_freefile(&(*ppf)->next); + + store_freebuffer(&(*ppf)->data); + (*ppf)->datacount = 0; + if ((*ppf)->palette != NULL) + { + free((*ppf)->palette); + (*ppf)->palette = NULL; + (*ppf)->npalette = 0; + } + free(*ppf); + *ppf = NULL; + } +} + +/* Main interface to file storeage, after writing a new PNG file (see the API + * below) call store_storefile to store the result with the given name and id. + */ +static void +store_storefile(png_store *ps, png_uint_32 id) +{ + png_store_file *pf = voidcast(png_store_file*, malloc(sizeof *pf)); + if (pf == NULL) + png_error(ps->pwrite, "storefile: OOM"); + safecat(pf->name, sizeof pf->name, 0, ps->wname); + pf->id = id; + pf->data = ps->new; + pf->datacount = ps->writepos; + ps->new.prev = NULL; + ps->writepos = 0; + pf->palette = ps->palette; + pf->npalette = ps->npalette; + ps->palette = 0; + ps->npalette = 0; + + /* And save it. */ + pf->next = ps->saved; + ps->saved = pf; +} + +/* Generate an error message (in the given buffer) */ +static size_t +store_message(png_store *ps, png_const_structp pp, char *buffer, size_t bufsize, + size_t pos, PNG_CONST char *msg) +{ + if (pp != NULL && pp == ps->pread) + { + /* Reading a file */ + pos = safecat(buffer, bufsize, pos, "read: "); + + if (ps->current != NULL) + { + pos = safecat(buffer, bufsize, pos, ps->current->name); + pos = safecat(buffer, bufsize, pos, sep); + } + } + + else if (pp != NULL && pp == ps->pwrite) + { + /* Writing a file */ + pos = safecat(buffer, bufsize, pos, "write: "); + pos = safecat(buffer, bufsize, pos, ps->wname); + pos = safecat(buffer, bufsize, pos, sep); + } + + else + { + /* Neither reading nor writing (or a memory error in struct delete) */ + pos = safecat(buffer, bufsize, pos, "pngvalid: "); + } + + if (ps->test[0] != 0) + { + pos = safecat(buffer, bufsize, pos, ps->test); + pos = safecat(buffer, bufsize, pos, sep); + } + pos = safecat(buffer, bufsize, pos, msg); + return pos; +} + +/* Verbose output to the error stream: */ +static void +store_verbose(png_store *ps, png_const_structp pp, png_const_charp prefix, + png_const_charp message) +{ + char buffer[512]; + + if (prefix) + fputs(prefix, stderr); + + (void)store_message(ps, pp, buffer, sizeof buffer, 0, message); + fputs(buffer, stderr); + fputc('\n', stderr); +} + +/* Log an error or warning - the relevant count is always incremented. */ +static void +store_log(png_store* ps, png_const_structp pp, png_const_charp message, + int is_error) +{ + /* The warning is copied to the error buffer if there are no errors and it is + * the first warning. The error is copied to the error buffer if it is the + * first error (overwriting any prior warnings). + */ + if (is_error ? (ps->nerrors)++ == 0 : + (ps->nwarnings)++ == 0 && ps->nerrors == 0) + store_message(ps, pp, ps->error, sizeof ps->error, 0, message); + + if (ps->verbose) + store_verbose(ps, pp, is_error ? "error: " : "warning: ", message); +} + +#ifdef PNG_READ_SUPPORTED +/* Internal error function, called with a png_store but no libpng stuff. */ +static void +internal_error(png_store *ps, png_const_charp message) +{ + store_log(ps, NULL, message, 1 /* error */); + + /* And finally throw an exception. */ + { + struct exception_context *the_exception_context = &ps->exception_context; + Throw ps; + } +} +#endif /* PNG_READ_SUPPORTED */ + +/* Functions to use as PNG callbacks. */ +static void PNGCBAPI +store_error(png_structp ppIn, png_const_charp message) /* PNG_NORETURN */ +{ + png_const_structp pp = ppIn; + png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); + + if (!ps->expect_error) + store_log(ps, pp, message, 1 /* error */); + + /* And finally throw an exception. */ + { + struct exception_context *the_exception_context = &ps->exception_context; + Throw ps; + } +} + +static void PNGCBAPI +store_warning(png_structp ppIn, png_const_charp message) +{ + png_const_structp pp = ppIn; + png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); + + if (!ps->expect_warning) + store_log(ps, pp, message, 0 /* warning */); + else + ps->saw_warning = 1; +} + +/* These somewhat odd functions are used when reading an image to ensure that + * the buffer is big enough, the png_structp is for errors. + */ +/* Return a single row from the correct image. */ +static png_bytep +store_image_row(PNG_CONST png_store* ps, png_const_structp pp, int nImage, + png_uint_32 y) +{ + png_size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2; + + if (ps->image == NULL) + png_error(pp, "no allocated image"); + + if (coffset + ps->cb_row + 3 > ps->cb_image) + png_error(pp, "image too small"); + + return ps->image + coffset; +} + +static void +store_image_free(png_store *ps, png_const_structp pp) +{ + if (ps->image != NULL) + { + png_bytep image = ps->image; + + if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) + { + if (pp != NULL) + png_error(pp, "png_store image overwrite (1)"); + else + store_log(ps, NULL, "png_store image overwrite (2)", 1); + } + + ps->image = NULL; + ps->cb_image = 0; + --image; + free(image); + } +} + +static void +store_ensure_image(png_store *ps, png_const_structp pp, int nImages, + png_size_t cbRow, png_uint_32 cRows) +{ + png_size_t cb = nImages * cRows * (cbRow + 5); + + if (ps->cb_image < cb) + { + png_bytep image; + + store_image_free(ps, pp); + + /* The buffer is deliberately mis-aligned. */ + image = voidcast(png_bytep, malloc(cb+2)); + if (image == NULL) + { + /* Called from the startup - ignore the error for the moment. */ + if (pp == NULL) + return; + + png_error(pp, "OOM allocating image buffer"); + } + + /* These magic tags are used to detect overwrites above. */ + ++image; + image[-1] = 0xed; + image[cb] = 0xfe; + + ps->image = image; + ps->cb_image = cb; + } + + /* We have an adequate sized image; lay out the rows. There are 2 bytes at + * the start and three at the end of each (this ensures that the row + * alignment starts out odd - 2+1 and changes for larger images on each row.) + */ + ps->cb_row = cbRow; + ps->image_h = cRows; + + /* For error checking, the whole buffer is set to 10110010 (0xb2 - 178). + * This deliberately doesn't match the bits in the size test image which are + * outside the image; these are set to 0xff (all 1). To make the row + * comparison work in the 'size' test case the size rows are pre-initialized + * to the same value prior to calling 'standard_row'. + */ + memset(ps->image, 178, cb); + + /* Then put in the marks. */ + while (--nImages >= 0) + { + png_uint_32 y; + + for (y=0; y<cRows; ++y) + { + png_bytep row = store_image_row(ps, pp, nImages, y); + + /* The markers: */ + row[-2] = 190; + row[-1] = 239; + row[cbRow] = 222; + row[cbRow+1] = 173; + row[cbRow+2] = 17; + } + } +} + +#ifdef PNG_READ_SUPPORTED +static void +store_image_check(PNG_CONST png_store* ps, png_const_structp pp, int iImage) +{ + png_const_bytep image = ps->image; + + if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) + png_error(pp, "image overwrite"); + else + { + png_size_t cbRow = ps->cb_row; + png_uint_32 rows = ps->image_h; + + image += iImage * (cbRow+5) * ps->image_h; + + image += 2; /* skip image first row markers */ + + while (rows-- > 0) + { + if (image[-2] != 190 || image[-1] != 239) + png_error(pp, "row start overwritten"); + + if (image[cbRow] != 222 || image[cbRow+1] != 173 || + image[cbRow+2] != 17) + png_error(pp, "row end overwritten"); + + image += cbRow+5; + } + } +} +#endif /* PNG_READ_SUPPORTED */ + +static void PNGCBAPI +store_write(png_structp ppIn, png_bytep pb, png_size_t st) +{ + png_const_structp pp = ppIn; + png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); + + if (ps->pwrite != pp) + png_error(pp, "store state damaged"); + + while (st > 0) + { + size_t cb; + + if (ps->writepos >= STORE_BUFFER_SIZE) + store_storenew(ps); + + cb = st; + + if (cb > STORE_BUFFER_SIZE - ps->writepos) + cb = STORE_BUFFER_SIZE - ps->writepos; + + memcpy(ps->new.buffer + ps->writepos, pb, cb); + pb += cb; + st -= cb; + ps->writepos += cb; + } +} + +static void PNGCBAPI +store_flush(png_structp ppIn) +{ + UNUSED(ppIn) /*DOES NOTHING*/ +} + +#ifdef PNG_READ_SUPPORTED +static size_t +store_read_buffer_size(png_store *ps) +{ + /* Return the bytes available for read in the current buffer. */ + if (ps->next != &ps->current->data) + return STORE_BUFFER_SIZE; + + return ps->current->datacount; +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* Return total bytes available for read. */ +static size_t +store_read_buffer_avail(png_store *ps) +{ + if (ps->current != NULL && ps->next != NULL) + { + png_store_buffer *next = &ps->current->data; + size_t cbAvail = ps->current->datacount; + + while (next != ps->next && next != NULL) + { + next = next->prev; + cbAvail += STORE_BUFFER_SIZE; + } + + if (next != ps->next) + png_error(ps->pread, "buffer read error"); + + if (cbAvail > ps->readpos) + return cbAvail - ps->readpos; + } + + return 0; +} +#endif + +static int +store_read_buffer_next(png_store *ps) +{ + png_store_buffer *pbOld = ps->next; + png_store_buffer *pbNew = &ps->current->data; + if (pbOld != pbNew) + { + while (pbNew != NULL && pbNew->prev != pbOld) + pbNew = pbNew->prev; + + if (pbNew != NULL) + { + ps->next = pbNew; + ps->readpos = 0; + return 1; + } + + png_error(ps->pread, "buffer lost"); + } + + return 0; /* EOF or error */ +} + +/* Need separate implementation and callback to allow use of the same code + * during progressive read, where the io_ptr is set internally by libpng. + */ +static void +store_read_imp(png_store *ps, png_bytep pb, png_size_t st) +{ + if (ps->current == NULL || ps->next == NULL) + png_error(ps->pread, "store state damaged"); + + while (st > 0) + { + size_t cbAvail = store_read_buffer_size(ps) - ps->readpos; + + if (cbAvail > 0) + { + if (cbAvail > st) cbAvail = st; + memcpy(pb, ps->next->buffer + ps->readpos, cbAvail); + st -= cbAvail; + pb += cbAvail; + ps->readpos += cbAvail; + } + + else if (!store_read_buffer_next(ps)) + png_error(ps->pread, "read beyond end of file"); + } +} + +static void PNGCBAPI +store_read(png_structp ppIn, png_bytep pb, png_size_t st) +{ + png_const_structp pp = ppIn; + png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); + + if (ps == NULL || ps->pread != pp) + png_error(pp, "bad store read call"); + + store_read_imp(ps, pb, st); +} + +static void +store_progressive_read(png_store *ps, png_structp pp, png_infop pi) +{ + /* Notice that a call to store_read will cause this function to fail because + * readpos will be set. + */ + if (ps->pread != pp || ps->current == NULL || ps->next == NULL) + png_error(pp, "store state damaged (progressive)"); + + do + { + if (ps->readpos != 0) + png_error(pp, "store_read called during progressive read"); + + png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps)); + } + while (store_read_buffer_next(ps)); +} +#endif /* PNG_READ_SUPPORTED */ + +/* The caller must fill this in: */ +static store_palette_entry * +store_write_palette(png_store *ps, int npalette) +{ + if (ps->pwrite == NULL) + store_log(ps, NULL, "attempt to write palette without write stream", 1); + + if (ps->palette != NULL) + png_error(ps->pwrite, "multiple store_write_palette calls"); + + /* This function can only return NULL if called with '0'! */ + if (npalette > 0) + { + ps->palette = voidcast(store_palette_entry*, malloc(npalette * + sizeof *ps->palette)); + + if (ps->palette == NULL) + png_error(ps->pwrite, "store new palette: OOM"); + + ps->npalette = npalette; + } + + return ps->palette; +} + +#ifdef PNG_READ_SUPPORTED +static store_palette_entry * +store_current_palette(png_store *ps, int *npalette) +{ + /* This is an internal error (the call has been made outside a read + * operation.) + */ + if (ps->current == NULL) + store_log(ps, ps->pread, "no current stream for palette", 1); + + /* The result may be null if there is no palette. */ + *npalette = ps->current->npalette; + return ps->current->palette; +} +#endif /* PNG_READ_SUPPORTED */ + +/***************************** MEMORY MANAGEMENT*** ***************************/ +#ifdef PNG_USER_MEM_SUPPORTED +/* A store_memory is simply the header for an allocated block of memory. The + * pointer returned to libpng is just after the end of the header block, the + * allocated memory is followed by a second copy of the 'mark'. + */ +typedef struct store_memory +{ + store_pool *pool; /* Originating pool */ + struct store_memory *next; /* Singly linked list */ + png_alloc_size_t size; /* Size of memory allocated */ + png_byte mark[4]; /* ID marker */ +} store_memory; + +/* Handle a fatal error in memory allocation. This calls png_error if the + * libpng struct is non-NULL, else it outputs a message and returns. This means + * that a memory problem while libpng is running will abort (png_error) the + * handling of particular file while one in cleanup (after the destroy of the + * struct has returned) will simply keep going and free (or attempt to free) + * all the memory. + */ +static void +store_pool_error(png_store *ps, png_const_structp pp, PNG_CONST char *msg) +{ + if (pp != NULL) + png_error(pp, msg); + + /* Else we have to do it ourselves. png_error eventually calls store_log, + * above. store_log accepts a NULL png_structp - it just changes what gets + * output by store_message. + */ + store_log(ps, pp, msg, 1 /* error */); +} + +static void +store_memory_free(png_const_structp pp, store_pool *pool, store_memory *memory) +{ + /* Note that pp may be NULL (see store_pool_delete below), the caller has + * found 'memory' in pool->list *and* unlinked this entry, so this is a valid + * pointer (for sure), but the contents may have been trashed. + */ + if (memory->pool != pool) + store_pool_error(pool->store, pp, "memory corrupted (pool)"); + + else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0) + store_pool_error(pool->store, pp, "memory corrupted (start)"); + + /* It should be safe to read the size field now. */ + else + { + png_alloc_size_t cb = memory->size; + + if (cb > pool->max) + store_pool_error(pool->store, pp, "memory corrupted (size)"); + + else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark) + != 0) + store_pool_error(pool->store, pp, "memory corrupted (end)"); + + /* Finally give the library a chance to find problems too: */ + else + { + pool->current -= cb; + free(memory); + } + } +} + +static void +store_pool_delete(png_store *ps, store_pool *pool) +{ + if (pool->list != NULL) + { + fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test, + pool == &ps->read_memory_pool ? "read" : "write", + pool == &ps->read_memory_pool ? (ps->current != NULL ? + ps->current->name : "unknown file") : ps->wname); + ++ps->nerrors; + + do + { + store_memory *next = pool->list; + pool->list = next->next; + next->next = NULL; + + fprintf(stderr, "\t%lu bytes @ %p\n", + (unsigned long)next->size, (PNG_CONST void*)(next+1)); + /* The NULL means this will always return, even if the memory is + * corrupted. + */ + store_memory_free(NULL, pool, next); + } + while (pool->list != NULL); + } + + /* And reset the other fields too for the next time. */ + if (pool->max > pool->max_max) pool->max_max = pool->max; + pool->max = 0; + if (pool->current != 0) /* unexpected internal error */ + fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n", + ps->test, pool == &ps->read_memory_pool ? "read" : "write", + pool == &ps->read_memory_pool ? (ps->current != NULL ? + ps->current->name : "unknown file") : ps->wname); + pool->current = 0; + + if (pool->limit > pool->max_limit) + pool->max_limit = pool->limit; + + pool->limit = 0; + + if (pool->total > pool->max_total) + pool->max_total = pool->total; + + pool->total = 0; + + /* Get a new mark too. */ + store_pool_mark(pool->mark); +} + +/* The memory callbacks: */ +static png_voidp PNGCBAPI +store_malloc(png_structp ppIn, png_alloc_size_t cb) +{ + png_const_structp pp = ppIn; + store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); + store_memory *new = voidcast(store_memory*, malloc(cb + (sizeof *new) + + (sizeof pool->mark))); + + if (new != NULL) + { + if (cb > pool->max) + pool->max = cb; + + pool->current += cb; + + if (pool->current > pool->limit) + pool->limit = pool->current; + + pool->total += cb; + + new->size = cb; + memcpy(new->mark, pool->mark, sizeof new->mark); + memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark); + new->pool = pool; + new->next = pool->list; + pool->list = new; + ++new; + } + + else + { + /* NOTE: the PNG user malloc function cannot use the png_ptr it is passed + * other than to retrieve the allocation pointer! libpng calls the + * store_malloc callback in two basic cases: + * + * 1) From png_malloc; png_malloc will do a png_error itself if NULL is + * returned. + * 2) From png_struct or png_info structure creation; png_malloc is + * to return so cleanup can be performed. + * + * To handle this store_malloc can log a message, but can't do anything + * else. + */ + store_log(pool->store, pp, "out of memory", 1 /* is_error */); + } + + return new; +} + +static void PNGCBAPI +store_free(png_structp ppIn, png_voidp memory) +{ + png_const_structp pp = ppIn; + store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); + store_memory *this = voidcast(store_memory*, memory), **test; + + /* Because libpng calls store_free with a dummy png_struct when deleting + * png_struct or png_info via png_destroy_struct_2 it is necessary to check + * the passed in png_structp to ensure it is valid, and not pass it to + * png_error if it is not. + */ + if (pp != pool->store->pread && pp != pool->store->pwrite) + pp = NULL; + + /* First check that this 'memory' really is valid memory - it must be in the + * pool list. If it is, use the shared memory_free function to free it. + */ + --this; + for (test = &pool->list; *test != this; test = &(*test)->next) + { + if (*test == NULL) + { + store_pool_error(pool->store, pp, "bad pointer to free"); + return; + } + } + + /* Unlink this entry, *test == this. */ + *test = this->next; + this->next = NULL; + store_memory_free(pp, pool, this); +} +#endif /* PNG_USER_MEM_SUPPORTED */ + +/* Setup functions. */ +/* Cleanup when aborting a write or after storing the new file. */ +static void +store_write_reset(png_store *ps) +{ + if (ps->pwrite != NULL) + { + anon_context(ps); + + Try + png_destroy_write_struct(&ps->pwrite, &ps->piwrite); + + Catch_anonymous + { + /* memory corruption: continue. */ + } + + ps->pwrite = NULL; + ps->piwrite = NULL; + } + + /* And make sure that all the memory has been freed - this will output + * spurious errors in the case of memory corruption above, but this is safe. + */ +# ifdef PNG_USER_MEM_SUPPORTED + store_pool_delete(ps, &ps->write_memory_pool); +# endif + + store_freenew(ps); +} + +/* The following is the main write function, it returns a png_struct and, + * optionally, a png_info suitable for writiing a new PNG file. Use + * store_storefile above to record this file after it has been written. The + * returned libpng structures as destroyed by store_write_reset above. + */ +static png_structp +set_store_for_write(png_store *ps, png_infopp ppi, + PNG_CONST char * volatile name) +{ + anon_context(ps); + + Try + { + if (ps->pwrite != NULL) + png_error(ps->pwrite, "write store already in use"); + + store_write_reset(ps); + safecat(ps->wname, sizeof ps->wname, 0, name); + + /* Don't do the slow memory checks if doing a speed test, also if user + * memory is not supported we can't do it anyway. + */ +# ifdef PNG_USER_MEM_SUPPORTED + if (!ps->speed) + ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, + ps, store_error, store_warning, &ps->write_memory_pool, + store_malloc, store_free); + + else +# endif + ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING, + ps, store_error, store_warning); + + png_set_write_fn(ps->pwrite, ps, store_write, store_flush); + +# ifdef PNG_SET_OPTION_SUPPORTED + { + int opt; + for (opt=0; opt<ps->noptions; ++opt) + if (png_set_option(ps->pwrite, ps->options[opt].option, + ps->options[opt].setting) == PNG_OPTION_INVALID) + png_error(ps->pwrite, "png option invalid"); + } +# endif + + if (ppi != NULL) + *ppi = ps->piwrite = png_create_info_struct(ps->pwrite); + } + + Catch_anonymous + return NULL; + + return ps->pwrite; +} + +/* Cleanup when finished reading (either due to error or in the success case). + * This routine exists even when there is no read support to make the code + * tidier (avoid a mass of ifdefs) and so easier to maintain. + */ +static void +store_read_reset(png_store *ps) +{ +# ifdef PNG_READ_SUPPORTED + if (ps->pread != NULL) + { + anon_context(ps); + + Try + png_destroy_read_struct(&ps->pread, &ps->piread, NULL); + + Catch_anonymous + { + /* error already output: continue */ + } + + ps->pread = NULL; + ps->piread = NULL; + } +# endif + +# ifdef PNG_USER_MEM_SUPPORTED + /* Always do this to be safe. */ + store_pool_delete(ps, &ps->read_memory_pool); +# endif + + ps->current = NULL; + ps->next = NULL; + ps->readpos = 0; + ps->validated = 0; +} + +#ifdef PNG_READ_SUPPORTED +static void +store_read_set(png_store *ps, png_uint_32 id) +{ + png_store_file *pf = ps->saved; + + while (pf != NULL) + { + if (pf->id == id) + { + ps->current = pf; + ps->next = NULL; + store_read_buffer_next(ps); + return; + } + + pf = pf->next; + } + + { + size_t pos; + char msg[FILE_NAME_SIZE+64]; + + pos = standard_name_from_id(msg, sizeof msg, 0, id); + pos = safecat(msg, sizeof msg, pos, ": file not found"); + png_error(ps->pread, msg); + } +} + +/* The main interface for reading a saved file - pass the id number of the file + * to retrieve. Ids must be unique or the earlier file will be hidden. The API + * returns a png_struct and, optionally, a png_info. Both of these will be + * destroyed by store_read_reset above. + */ +static png_structp +set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id, + PNG_CONST char *name) +{ + /* Set the name for png_error */ + safecat(ps->test, sizeof ps->test, 0, name); + + if (ps->pread != NULL) + png_error(ps->pread, "read store already in use"); + + store_read_reset(ps); + + /* Both the create APIs can return NULL if used in their default mode + * (because there is no other way of handling an error because the jmp_buf + * by default is stored in png_struct and that has not been allocated!) + * However, given that store_error works correctly in these circumstances + * we don't ever expect NULL in this program. + */ +# ifdef PNG_USER_MEM_SUPPORTED + if (!ps->speed) + ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps, + store_error, store_warning, &ps->read_memory_pool, store_malloc, + store_free); + + else +# endif + ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, store_error, + store_warning); + + if (ps->pread == NULL) + { + struct exception_context *the_exception_context = &ps->exception_context; + + store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)", + 1 /*error*/); + + Throw ps; + } + +# ifdef PNG_SET_OPTION_SUPPORTED + { + int opt; + for (opt=0; opt<ps->noptions; ++opt) + if (png_set_option(ps->pread, ps->options[opt].option, + ps->options[opt].setting) == PNG_OPTION_INVALID) + png_error(ps->pread, "png option invalid"); + } +# endif + + store_read_set(ps, id); + + if (ppi != NULL) + *ppi = ps->piread = png_create_info_struct(ps->pread); + + return ps->pread; +} +#endif /* PNG_READ_SUPPORTED */ + +/* The overall cleanup of a store simply calls the above then removes all the + * saved files. This does not delete the store itself. + */ +static void +store_delete(png_store *ps) +{ + store_write_reset(ps); + store_read_reset(ps); + store_freefile(&ps->saved); + store_image_free(ps, NULL); +} + +/*********************** PNG FILE MODIFICATION ON READ ************************/ +/* Files may be modified on read. The following structure contains a complete + * png_store together with extra members to handle modification and a special + * read callback for libpng. To use this the 'modifications' field must be set + * to a list of png_modification structures that actually perform the + * modification, otherwise a png_modifier is functionally equivalent to a + * png_store. There is a special read function, set_modifier_for_read, which + * replaces set_store_for_read. + */ +typedef enum modifier_state +{ + modifier_start, /* Initial value */ + modifier_signature, /* Have a signature */ + modifier_IHDR /* Have an IHDR */ +} modifier_state; + +typedef struct CIE_color +{ + /* A single CIE tristimulus value, representing the unique response of a + * standard observer to a variety of light spectra. The observer recognizes + * all spectra that produce this response as the same color, therefore this + * is effectively a description of a color. + */ + double X, Y, Z; +} CIE_color; + +typedef struct color_encoding +{ + /* A description of an (R,G,B) encoding of color (as defined above); this + * includes the actual colors of the (R,G,B) triples (1,0,0), (0,1,0) and + * (0,0,1) plus an encoding value that is used to encode the linear + * components R, G and B to give the actual values R^gamma, G^gamma and + * B^gamma that are stored. + */ + double gamma; /* Encoding (file) gamma of space */ + CIE_color red, green, blue; /* End points */ +} color_encoding; + +#ifdef PNG_READ_SUPPORTED +static double +chromaticity_x(CIE_color c) +{ + return c.X / (c.X + c.Y + c.Z); +} + +static double +chromaticity_y(CIE_color c) +{ + return c.Y / (c.X + c.Y + c.Z); +} + +static CIE_color +white_point(PNG_CONST color_encoding *encoding) +{ + CIE_color white; + + white.X = encoding->red.X + encoding->green.X + encoding->blue.X; + white.Y = encoding->red.Y + encoding->green.Y + encoding->blue.Y; + white.Z = encoding->red.Z + encoding->green.Z + encoding->blue.Z; + + return white; +} + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +static void +normalize_color_encoding(color_encoding *encoding) +{ + PNG_CONST double whiteY = encoding->red.Y + encoding->green.Y + + encoding->blue.Y; + + if (whiteY != 1) + { + encoding->red.X /= whiteY; + encoding->red.Y /= whiteY; + encoding->red.Z /= whiteY; + encoding->green.X /= whiteY; + encoding->green.Y /= whiteY; + encoding->green.Z /= whiteY; + encoding->blue.X /= whiteY; + encoding->blue.Y /= whiteY; + encoding->blue.Z /= whiteY; + } +} +#endif + +static size_t +safecat_color_encoding(char *buffer, size_t bufsize, size_t pos, + PNG_CONST color_encoding *e, double encoding_gamma) +{ + if (e != 0) + { + if (encoding_gamma != 0) + pos = safecat(buffer, bufsize, pos, "("); + pos = safecat(buffer, bufsize, pos, "R("); + pos = safecatd(buffer, bufsize, pos, e->red.X, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->red.Y, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->red.Z, 4); + pos = safecat(buffer, bufsize, pos, "),G("); + pos = safecatd(buffer, bufsize, pos, e->green.X, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->green.Y, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->green.Z, 4); + pos = safecat(buffer, bufsize, pos, "),B("); + pos = safecatd(buffer, bufsize, pos, e->blue.X, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->blue.Y, 4); + pos = safecat(buffer, bufsize, pos, ","); + pos = safecatd(buffer, bufsize, pos, e->blue.Z, 4); + pos = safecat(buffer, bufsize, pos, ")"); + if (encoding_gamma != 0) + pos = safecat(buffer, bufsize, pos, ")"); + } + + if (encoding_gamma != 0) + { + pos = safecat(buffer, bufsize, pos, "^"); + pos = safecatd(buffer, bufsize, pos, encoding_gamma, 5); + } + + return pos; +} +#endif /* PNG_READ_SUPPORTED */ + +typedef struct png_modifier +{ + png_store this; /* I am a png_store */ + struct png_modification *modifications; /* Changes to make */ + + modifier_state state; /* My state */ + + /* Information from IHDR: */ + png_byte bit_depth; /* From IHDR */ + png_byte colour_type; /* From IHDR */ + + /* While handling PLTE, IDAT and IEND these chunks may be pended to allow + * other chunks to be inserted. + */ + png_uint_32 pending_len; + png_uint_32 pending_chunk; + + /* Test values */ + double *gammas; + unsigned int ngammas; + unsigned int ngamma_tests; /* Number of gamma tests to run*/ + double current_gamma; /* 0 if not set */ + PNG_CONST color_encoding *encodings; + unsigned int nencodings; + PNG_CONST color_encoding *current_encoding; /* If an encoding has been set */ + unsigned int encoding_counter; /* For iteration */ + int encoding_ignored; /* Something overwrote it */ + + /* Control variables used to iterate through possible encodings, the + * following must be set to 0 and tested by the function that uses the + * png_modifier because the modifier only sets it to 1 (true.) + */ + unsigned int repeat :1; /* Repeat this transform test. */ + unsigned int test_uses_encoding :1; + + /* Lowest sbit to test (libpng fails for sbit < 8) */ + png_byte sbitlow; + + /* Error control - these are the limits on errors accepted by the gamma tests + * below. + */ + double maxout8; /* Maximum output value error */ + double maxabs8; /* Absolute sample error 0..1 */ + double maxcalc8; /* Absolute sample error 0..1 */ + double maxpc8; /* Percentage sample error 0..100% */ + double maxout16; /* Maximum output value error */ + double maxabs16; /* Absolute sample error 0..1 */ + double maxcalc16;/* Absolute sample error 0..1 */ + double maxcalcG; /* Absolute sample error 0..1 */ + double maxpc16; /* Percentage sample error 0..100% */ + + /* This is set by transforms that need to allow a higher limit, it is an + * internal check on pngvalid to ensure that the calculated error limits are + * not ridiculous; without this it is too easy to make a mistake in pngvalid + * that allows any value through. + */ + double limit; /* limit on error values, normally 4E-3 */ + + /* Log limits - values above this are logged, but not necessarily + * warned. + */ + double log8; /* Absolute error in 8 bits to log */ + double log16; /* Absolute error in 16 bits to log */ + + /* Logged 8 and 16 bit errors ('output' values): */ + double error_gray_2; + double error_gray_4; + double error_gray_8; + double error_gray_16; + double error_color_8; + double error_color_16; + double error_indexed; + + /* Flags: */ + /* Whether to call png_read_update_info, not png_read_start_image, and how + * many times to call it. + */ + int use_update_info; + + /* Whether or not to interlace. */ + int interlace_type :9; /* int, but must store '1' */ + + /* Run the standard tests? */ + unsigned int test_standard :1; + + /* Run the odd-sized image and interlace read/write tests? */ + unsigned int test_size :1; + + /* Run tests on reading with a combination of transforms, */ + unsigned int test_transform :1; + + /* When to use the use_input_precision option, this controls the gamma + * validation code checks. If set any value that is within the transformed + * range input-.5 to input+.5 will be accepted, otherwise the value must be + * within the normal limits. It should not be necessary to set this; the + * result should always be exact within the permitted error limits. + */ + unsigned int use_input_precision :1; + unsigned int use_input_precision_sbit :1; + unsigned int use_input_precision_16to8 :1; + + /* If set assume that the calculation bit depth is set by the input + * precision, not the output precision. + */ + unsigned int calculations_use_input_precision :1; + + /* If set assume that the calculations are done in 16 bits even if the sample + * depth is 8 bits. + */ + unsigned int assume_16_bit_calculations :1; + + /* Which gamma tests to run: */ + unsigned int test_gamma_threshold :1; + unsigned int test_gamma_transform :1; /* main tests */ + unsigned int test_gamma_sbit :1; + unsigned int test_gamma_scale16 :1; + unsigned int test_gamma_background :1; + unsigned int test_gamma_alpha_mode :1; + unsigned int test_gamma_expand16 :1; + unsigned int test_exhaustive :1; + + unsigned int log :1; /* Log max error */ + + /* Buffer information, the buffer size limits the size of the chunks that can + * be modified - they must fit (including header and CRC) into the buffer! + */ + size_t flush; /* Count of bytes to flush */ + size_t buffer_count; /* Bytes in buffer */ + size_t buffer_position; /* Position in buffer */ + png_byte buffer[1024]; +} png_modifier; + +/* This returns true if the test should be stopped now because it has already + * failed and it is running silently. + */ +static int fail(png_modifier *pm) +{ + return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 || + (pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0)); +} + +static void +modifier_init(png_modifier *pm) +{ + memset(pm, 0, sizeof *pm); + store_init(&pm->this); + pm->modifications = NULL; + pm->state = modifier_start; + pm->sbitlow = 1U; + pm->ngammas = 0; + pm->ngamma_tests = 0; + pm->gammas = 0; + pm->current_gamma = 0; + pm->encodings = 0; + pm->nencodings = 0; + pm->current_encoding = 0; + pm->encoding_counter = 0; + pm->encoding_ignored = 0; + pm->repeat = 0; + pm->test_uses_encoding = 0; + pm->maxout8 = pm->maxpc8 = pm->maxabs8 = pm->maxcalc8 = 0; + pm->maxout16 = pm->maxpc16 = pm->maxabs16 = pm->maxcalc16 = 0; + pm->maxcalcG = 0; + pm->limit = 4E-3; + pm->log8 = pm->log16 = 0; /* Means 'off' */ + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; + pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; + pm->error_indexed = 0; + pm->use_update_info = 0; + pm->interlace_type = PNG_INTERLACE_NONE; + pm->test_standard = 0; + pm->test_size = 0; + pm->test_transform = 0; + pm->use_input_precision = 0; + pm->use_input_precision_sbit = 0; + pm->use_input_precision_16to8 = 0; + pm->calculations_use_input_precision = 0; + pm->assume_16_bit_calculations = 0; + pm->test_gamma_threshold = 0; + pm->test_gamma_transform = 0; + pm->test_gamma_sbit = 0; + pm->test_gamma_scale16 = 0; + pm->test_gamma_background = 0; + pm->test_gamma_alpha_mode = 0; + pm->test_gamma_expand16 = 0; + pm->test_exhaustive = 0; + pm->log = 0; + + /* Rely on the memset for all the other fields - there are no pointers */ +} + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + +/* This controls use of checks that explicitly know how libpng digitizes the + * samples in calculations; setting this circumvents simple error limit checking + * in the rgb_to_gray check, replacing it with an exact copy of the libpng 1.5 + * algorithm. + */ +#define DIGITIZE PNG_LIBPNG_VER < 10700 + +/* If pm->calculations_use_input_precision is set then operations will happen + * with the precision of the input, not the precision of the output depth. + * + * If pm->assume_16_bit_calculations is set then even 8 bit calculations use 16 + * bit precision. This only affects those of the following limits that pertain + * to a calculation - not a digitization operation - unless the following API is + * called directly. + */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +#if DIGITIZE +static double digitize(double value, int depth, int do_round) +{ + /* 'value' is in the range 0 to 1, the result is the same value rounded to a + * multiple of the digitization factor - 8 or 16 bits depending on both the + * sample depth and the 'assume' setting. Digitization is normally by + * rounding and 'do_round' should be 1, if it is 0 the digitized value will + * be truncated. + */ + PNG_CONST unsigned int digitization_factor = (1U << depth) -1; + + /* Limiting the range is done as a convenience to the caller - it's easier to + * do it once here than every time at the call site. + */ + if (value <= 0) + value = 0; + + else if (value >= 1) + value = 1; + + value *= digitization_factor; + if (do_round) value += .5; + return floor(value)/digitization_factor; +} +#endif +#endif /* RGB_TO_GRAY */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +static double abserr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* Absolute error permitted in linear values - affected by the bit depth of + * the calculations. + */ + if (pm->assume_16_bit_calculations || + (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + return pm->maxabs16; + else + return pm->maxabs8; +} + +static double calcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* Error in the linear composition arithmetic - only relevant when + * composition actually happens (0 < alpha < 1). + */ + if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + return pm->maxcalc16; + else if (pm->assume_16_bit_calculations) + return pm->maxcalcG; + else + return pm->maxcalc8; +} + +static double pcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* Percentage error permitted in the linear values. Note that the specified + * value is a percentage but this routine returns a simple number. + */ + if (pm->assume_16_bit_calculations || + (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + return pm->maxpc16 * .01; + else + return pm->maxpc8 * .01; +} + +/* Output error - the error in the encoded value. This is determined by the + * digitization of the output so can be +/-0.5 in the actual output value. In + * the expand_16 case with the current code in libpng the expand happens after + * all the calculations are done in 8 bit arithmetic, so even though the output + * depth is 16 the output error is determined by the 8 bit calculation. + * + * This limit is not determined by the bit depth of internal calculations. + * + * The specified parameter does *not* include the base .5 digitization error but + * it is added here. + */ +static double outerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* There is a serious error in the 2 and 4 bit grayscale transform because + * the gamma table value (8 bits) is simply shifted, not rounded, so the + * error in 4 bit grayscale gamma is up to the value below. This is a hack + * to allow pngvalid to succeed: + * + * TODO: fix this in libpng + */ + if (out_depth == 2) + return .73182-.5; + + if (out_depth == 4) + return .90644-.5; + + if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + return pm->maxout16; + + /* This is the case where the value was calculated at 8-bit precision then + * scaled to 16 bits. + */ + else if (out_depth == 16) + return pm->maxout8 * 257; + + else + return pm->maxout8; +} + +/* This does the same thing as the above however it returns the value to log, + * rather than raising a warning. This is useful for debugging to track down + * exactly what set of parameters cause high error values. + */ +static double outlog(PNG_CONST png_modifier *pm, int in_depth, int out_depth) +{ + /* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535) + * and so must be adjusted for low bit depth grayscale: + */ + if (out_depth <= 8) + { + if (pm->log8 == 0) /* switched off */ + return 256; + + if (out_depth < 8) + return pm->log8 / 255 * ((1<<out_depth)-1); + + return pm->log8; + } + + if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) + { + if (pm->log16 == 0) + return 65536; + + return pm->log16; + } + + /* This is the case where the value was calculated at 8-bit precision then + * scaled to 16 bits. + */ + if (pm->log8 == 0) + return 65536; + + return pm->log8 * 257; +} + +/* This complements the above by providing the appropriate quantization for the + * final value. Normally this would just be quantization to an integral value, + * but in the 8 bit calculation case it's actually quantization to a multiple of + * 257! + */ +static int output_quantization_factor(PNG_CONST png_modifier *pm, int in_depth, + int out_depth) +{ + if (out_depth == 16 && in_depth != 16 && + pm->calculations_use_input_precision) + return 257; + else + return 1; +} +#endif /* PNG_READ_GAMMA_SUPPORTED */ + +/* One modification structure must be provided for each chunk to be modified (in + * fact more than one can be provided if multiple separate changes are desired + * for a single chunk.) Modifications include adding a new chunk when a + * suitable chunk does not exist. + * + * The caller of modify_fn will reset the CRC of the chunk and record 'modified' + * or 'added' as appropriate if the modify_fn returns 1 (true). If the + * modify_fn is NULL the chunk is simply removed. + */ +typedef struct png_modification +{ + struct png_modification *next; + png_uint_32 chunk; + + /* If the following is NULL all matching chunks will be removed: */ + int (*modify_fn)(struct png_modifier *pm, + struct png_modification *me, int add); + + /* If the following is set to PLTE, IDAT or IEND and the chunk has not been + * found and modified (and there is a modify_fn) the modify_fn will be called + * to add the chunk before the relevant chunk. + */ + png_uint_32 add; + unsigned int modified :1; /* Chunk was modified */ + unsigned int added :1; /* Chunk was added */ + unsigned int removed :1; /* Chunk was removed */ +} png_modification; + +static void +modification_reset(png_modification *pmm) +{ + if (pmm != NULL) + { + pmm->modified = 0; + pmm->added = 0; + pmm->removed = 0; + modification_reset(pmm->next); + } +} + +static void +modification_init(png_modification *pmm) +{ + memset(pmm, 0, sizeof *pmm); + pmm->next = NULL; + pmm->chunk = 0; + pmm->modify_fn = NULL; + pmm->add = 0; + modification_reset(pmm); +} + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +static void +modifier_current_encoding(PNG_CONST png_modifier *pm, color_encoding *ce) +{ + if (pm->current_encoding != 0) + *ce = *pm->current_encoding; + + else + memset(ce, 0, sizeof *ce); + + ce->gamma = pm->current_gamma; +} +#endif + +static size_t +safecat_current_encoding(char *buffer, size_t bufsize, size_t pos, + PNG_CONST png_modifier *pm) +{ + pos = safecat_color_encoding(buffer, bufsize, pos, pm->current_encoding, + pm->current_gamma); + + if (pm->encoding_ignored) + pos = safecat(buffer, bufsize, pos, "[overridden]"); + + return pos; +} + +/* Iterate through the usefully testable color encodings. An encoding is one + * of: + * + * 1) Nothing (no color space, no gamma). + * 2) Just a gamma value from the gamma array (including 1.0) + * 3) A color space from the encodings array with the corresponding gamma. + * 4) The same, but with gamma 1.0 (only really useful with 16 bit calculations) + * + * The iterator selects these in turn, the randomizer selects one at random, + * which is used depends on the setting of the 'test_exhaustive' flag. Notice + * that this function changes the colour space encoding so it must only be + * called on completion of the previous test. This is what 'modifier_reset' + * does, below. + * + * After the function has been called the 'repeat' flag will still be set; the + * caller of modifier_reset must reset it at the start of each run of the test! + */ +static unsigned int +modifier_total_encodings(PNG_CONST png_modifier *pm) +{ + return 1 + /* (1) nothing */ + pm->ngammas + /* (2) gamma values to test */ + pm->nencodings + /* (3) total number of encodings */ + /* The following test only works after the first time through the + * png_modifier code because 'bit_depth' is set when the IHDR is read. + * modifier_reset, below, preserves the setting until after it has called + * the iterate function (also below.) + * + * For this reason do not rely on this function outside a call to + * modifier_reset. + */ + ((pm->bit_depth == 16 || pm->assume_16_bit_calculations) ? + pm->nencodings : 0); /* (4) encodings with gamma == 1.0 */ +} + +static void +modifier_encoding_iterate(png_modifier *pm) +{ + if (!pm->repeat && /* Else something needs the current encoding again. */ + pm->test_uses_encoding) /* Some transform is encoding dependent */ + { + if (pm->test_exhaustive) + { + if (++pm->encoding_counter >= modifier_total_encodings(pm)) + pm->encoding_counter = 0; /* This will stop the repeat */ + } + + else + { + /* Not exhaustive - choose an encoding at random; generate a number in + * the range 1..(max-1), so the result is always non-zero: + */ + if (pm->encoding_counter == 0) + pm->encoding_counter = random_mod(modifier_total_encodings(pm)-1)+1; + else + pm->encoding_counter = 0; + } + + if (pm->encoding_counter > 0) + pm->repeat = 1; + } + + else if (!pm->repeat) + pm->encoding_counter = 0; +} + +static void +modifier_reset(png_modifier *pm) +{ + store_read_reset(&pm->this); + pm->limit = 4E-3; + pm->pending_len = pm->pending_chunk = 0; + pm->flush = pm->buffer_count = pm->buffer_position = 0; + pm->modifications = NULL; + pm->state = modifier_start; + modifier_encoding_iterate(pm); + /* The following must be set in the next run. In particular + * test_uses_encodings must be set in the _ini function of each transform + * that looks at the encodings. (Not the 'add' function!) + */ + pm->test_uses_encoding = 0; + pm->current_gamma = 0; + pm->current_encoding = 0; + pm->encoding_ignored = 0; + /* These only become value after IHDR is read: */ + pm->bit_depth = pm->colour_type = 0; +} + +/* The following must be called before anything else to get the encoding set up + * on the modifier. In particular it must be called before the transform init + * functions are called. + */ +static void +modifier_set_encoding(png_modifier *pm) +{ + /* Set the encoding to the one specified by the current encoding counter, + * first clear out all the settings - this corresponds to an encoding_counter + * of 0. + */ + pm->current_gamma = 0; + pm->current_encoding = 0; + pm->encoding_ignored = 0; /* not ignored yet - happens in _ini functions. */ + + /* Now, if required, set the gamma and encoding fields. */ + if (pm->encoding_counter > 0) + { + /* The gammas[] array is an array of screen gammas, not encoding gammas, + * so we need the inverse: + */ + if (pm->encoding_counter <= pm->ngammas) + pm->current_gamma = 1/pm->gammas[pm->encoding_counter-1]; + + else + { + unsigned int i = pm->encoding_counter - pm->ngammas; + + if (i >= pm->nencodings) + { + i %= pm->nencodings; + pm->current_gamma = 1; /* Linear, only in the 16 bit case */ + } + + else + pm->current_gamma = pm->encodings[i].gamma; + + pm->current_encoding = pm->encodings + i; + } + } +} + +/* Enquiry functions to find out what is set. Notice that there is an implicit + * assumption below that the first encoding in the list is the one for sRGB. + */ +static int +modifier_color_encoding_is_sRGB(PNG_CONST png_modifier *pm) +{ + return pm->current_encoding != 0 && pm->current_encoding == pm->encodings && + pm->current_encoding->gamma == pm->current_gamma; +} + +static int +modifier_color_encoding_is_set(PNG_CONST png_modifier *pm) +{ + return pm->current_gamma != 0; +} + +/* Convenience macros. */ +#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) +#define CHUNK_IHDR CHUNK(73,72,68,82) +#define CHUNK_PLTE CHUNK(80,76,84,69) +#define CHUNK_IDAT CHUNK(73,68,65,84) +#define CHUNK_IEND CHUNK(73,69,78,68) +#define CHUNK_cHRM CHUNK(99,72,82,77) +#define CHUNK_gAMA CHUNK(103,65,77,65) +#define CHUNK_sBIT CHUNK(115,66,73,84) +#define CHUNK_sRGB CHUNK(115,82,71,66) + +/* The guts of modification are performed during a read. */ +static void +modifier_crc(png_bytep buffer) +{ + /* Recalculate the chunk CRC - a complete chunk must be in + * the buffer, at the start. + */ + uInt datalen = png_get_uint_32(buffer); + uLong crc = crc32(0, buffer+4, datalen+4); + /* The cast to png_uint_32 is safe because a crc32 is always a 32 bit value. + */ + png_save_uint_32(buffer+datalen+8, (png_uint_32)crc); +} + +static void +modifier_setbuffer(png_modifier *pm) +{ + modifier_crc(pm->buffer); + pm->buffer_count = png_get_uint_32(pm->buffer)+12; + pm->buffer_position = 0; +} + +/* Separate the callback into the actual implementation (which is passed the + * png_modifier explicitly) and the callback, which gets the modifier from the + * png_struct. + */ +static void +modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st) +{ + while (st > 0) + { + size_t cb; + png_uint_32 len, chunk; + png_modification *mod; + + if (pm->buffer_position >= pm->buffer_count) switch (pm->state) + { + static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 }; + case modifier_start: + store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */ + pm->buffer_count = 8; + pm->buffer_position = 0; + + if (memcmp(pm->buffer, sign, 8) != 0) + png_error(pm->this.pread, "invalid PNG file signature"); + pm->state = modifier_signature; + break; + + case modifier_signature: + store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */ + pm->buffer_count = 13+12; + pm->buffer_position = 0; + + if (png_get_uint_32(pm->buffer) != 13 || + png_get_uint_32(pm->buffer+4) != CHUNK_IHDR) + png_error(pm->this.pread, "invalid IHDR"); + + /* Check the list of modifiers for modifications to the IHDR. */ + mod = pm->modifications; + while (mod != NULL) + { + if (mod->chunk == CHUNK_IHDR && mod->modify_fn && + (*mod->modify_fn)(pm, mod, 0)) + { + mod->modified = 1; + modifier_setbuffer(pm); + } + + /* Ignore removal or add if IHDR! */ + mod = mod->next; + } + + /* Cache information from the IHDR (the modified one.) */ + pm->bit_depth = pm->buffer[8+8]; + pm->colour_type = pm->buffer[8+8+1]; + + pm->state = modifier_IHDR; + pm->flush = 0; + break; + + case modifier_IHDR: + default: + /* Read a new chunk and process it until we see PLTE, IDAT or + * IEND. 'flush' indicates that there is still some data to + * output from the preceding chunk. + */ + if ((cb = pm->flush) > 0) + { + if (cb > st) cb = st; + pm->flush -= cb; + store_read_imp(&pm->this, pb, cb); + pb += cb; + st -= cb; + if (st == 0) return; + } + + /* No more bytes to flush, read a header, or handle a pending + * chunk. + */ + if (pm->pending_chunk != 0) + { + png_save_uint_32(pm->buffer, pm->pending_len); + png_save_uint_32(pm->buffer+4, pm->pending_chunk); + pm->pending_len = 0; + pm->pending_chunk = 0; + } + else + store_read_imp(&pm->this, pm->buffer, 8); + + pm->buffer_count = 8; + pm->buffer_position = 0; + + /* Check for something to modify or a terminator chunk. */ + len = png_get_uint_32(pm->buffer); + chunk = png_get_uint_32(pm->buffer+4); + + /* Terminators first, they may have to be delayed for added + * chunks + */ + if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT || + chunk == CHUNK_IEND) + { + mod = pm->modifications; + + while (mod != NULL) + { + if ((mod->add == chunk || + (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) && + mod->modify_fn != NULL && !mod->modified && !mod->added) + { + /* Regardless of what the modify function does do not run + * this again. + */ + mod->added = 1; + + if ((*mod->modify_fn)(pm, mod, 1 /*add*/)) + { + /* Reset the CRC on a new chunk */ + if (pm->buffer_count > 0) + modifier_setbuffer(pm); + + else + { + pm->buffer_position = 0; + mod->removed = 1; + } + + /* The buffer has been filled with something (we assume) + * so output this. Pend the current chunk. + */ + pm->pending_len = len; + pm->pending_chunk = chunk; + break; /* out of while */ + } + } + + mod = mod->next; + } + + /* Don't do any further processing if the buffer was modified - + * otherwise the code will end up modifying a chunk that was + * just added. + */ + if (mod != NULL) + break; /* out of switch */ + } + + /* If we get to here then this chunk may need to be modified. To + * do this it must be less than 1024 bytes in total size, otherwise + * it just gets flushed. + */ + if (len+12 <= sizeof pm->buffer) + { + store_read_imp(&pm->this, pm->buffer+pm->buffer_count, + len+12-pm->buffer_count); + pm->buffer_count = len+12; + + /* Check for a modification, else leave it be. */ + mod = pm->modifications; + while (mod != NULL) + { + if (mod->chunk == chunk) + { + if (mod->modify_fn == NULL) + { + /* Remove this chunk */ + pm->buffer_count = pm->buffer_position = 0; + mod->removed = 1; + break; /* Terminate the while loop */ + } + + else if ((*mod->modify_fn)(pm, mod, 0)) + { + mod->modified = 1; + /* The chunk may have been removed: */ + if (pm->buffer_count == 0) + { + pm->buffer_position = 0; + break; + } + modifier_setbuffer(pm); + } + } + + mod = mod->next; + } + } + + else + pm->flush = len+12 - pm->buffer_count; /* data + crc */ + + /* Take the data from the buffer (if there is any). */ + break; + } + + /* Here to read from the modifier buffer (not directly from + * the store, as in the flush case above.) + */ + cb = pm->buffer_count - pm->buffer_position; + + if (cb > st) + cb = st; + + memcpy(pb, pm->buffer + pm->buffer_position, cb); + st -= cb; + pb += cb; + pm->buffer_position += cb; + } +} + +/* The callback: */ +static void PNGCBAPI +modifier_read(png_structp ppIn, png_bytep pb, png_size_t st) +{ + png_const_structp pp = ppIn; + png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp)); + + if (pm == NULL || pm->this.pread != pp) + png_error(pp, "bad modifier_read call"); + + modifier_read_imp(pm, pb, st); +} + +/* Like store_progressive_read but the data is getting changed as we go so we + * need a local buffer. + */ +static void +modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi) +{ + if (pm->this.pread != pp || pm->this.current == NULL || + pm->this.next == NULL) + png_error(pp, "store state damaged (progressive)"); + + /* This is another Horowitz and Hill random noise generator. In this case + * the aim is to stress the progressive reader with truly horrible variable + * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers + * is generated. We could probably just count from 1 to 32767 and get as + * good a result. + */ + for (;;) + { + static png_uint_32 noise = 1; + png_size_t cb, cbAvail; + png_byte buffer[512]; + + /* Generate 15 more bits of stuff: */ + noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); + cb = noise & 0x1ff; + + /* Check that this number of bytes are available (in the current buffer.) + * (This doesn't quite work - the modifier might delete a chunk; unlikely + * but possible, it doesn't happen at present because the modifier only + * adds chunks to standard images.) + */ + cbAvail = store_read_buffer_avail(&pm->this); + if (pm->buffer_count > pm->buffer_position) + cbAvail += pm->buffer_count - pm->buffer_position; + + if (cb > cbAvail) + { + /* Check for EOF: */ + if (cbAvail == 0) + break; + + cb = cbAvail; + } + + modifier_read_imp(pm, buffer, cb); + png_process_data(pp, pi, buffer, cb); + } + + /* Check the invariants at the end (if this fails it's a problem in this + * file!) + */ + if (pm->buffer_count > pm->buffer_position || + pm->this.next != &pm->this.current->data || + pm->this.readpos < pm->this.current->datacount) + png_error(pp, "progressive read implementation error"); +} + +/* Set up a modifier. */ +static png_structp +set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id, + PNG_CONST char *name) +{ + /* Do this first so that the modifier fields are cleared even if an error + * happens allocating the png_struct. No allocation is done here so no + * cleanup is required. + */ + pm->state = modifier_start; + pm->bit_depth = 0; + pm->colour_type = 255; + + pm->pending_len = 0; + pm->pending_chunk = 0; + pm->flush = 0; + pm->buffer_count = 0; + pm->buffer_position = 0; + + return set_store_for_read(&pm->this, ppi, id, name); +} + + +/******************************** MODIFICATIONS *******************************/ +/* Standard modifications to add chunks. These do not require the _SUPPORTED + * macros because the chunks can be there regardless of whether this specific + * libpng supports them. + */ +typedef struct gama_modification +{ + png_modification this; + png_fixed_point gamma; +} gama_modification; + +static int +gama_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* This simply dumps the given gamma value into the buffer. */ + png_save_uint_32(pm->buffer, 4); + png_save_uint_32(pm->buffer+4, CHUNK_gAMA); + png_save_uint_32(pm->buffer+8, ((gama_modification*)me)->gamma); + return 1; +} + +static void +gama_modification_init(gama_modification *me, png_modifier *pm, double gammad) +{ + double g; + + modification_init(&me->this); + me->this.chunk = CHUNK_gAMA; + me->this.modify_fn = gama_modify; + me->this.add = CHUNK_PLTE; + g = fix(gammad); + me->gamma = (png_fixed_point)g; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +typedef struct chrm_modification +{ + png_modification this; + PNG_CONST color_encoding *encoding; + png_fixed_point wx, wy, rx, ry, gx, gy, bx, by; +} chrm_modification; + +static int +chrm_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* As with gAMA this just adds the required cHRM chunk to the buffer. */ + png_save_uint_32(pm->buffer , 32); + png_save_uint_32(pm->buffer+ 4, CHUNK_cHRM); + png_save_uint_32(pm->buffer+ 8, ((chrm_modification*)me)->wx); + png_save_uint_32(pm->buffer+12, ((chrm_modification*)me)->wy); + png_save_uint_32(pm->buffer+16, ((chrm_modification*)me)->rx); + png_save_uint_32(pm->buffer+20, ((chrm_modification*)me)->ry); + png_save_uint_32(pm->buffer+24, ((chrm_modification*)me)->gx); + png_save_uint_32(pm->buffer+28, ((chrm_modification*)me)->gy); + png_save_uint_32(pm->buffer+32, ((chrm_modification*)me)->bx); + png_save_uint_32(pm->buffer+36, ((chrm_modification*)me)->by); + return 1; +} + +static void +chrm_modification_init(chrm_modification *me, png_modifier *pm, + PNG_CONST color_encoding *encoding) +{ + CIE_color white = white_point(encoding); + + /* Original end points: */ + me->encoding = encoding; + + /* Chromaticities (in fixed point): */ + me->wx = fix(chromaticity_x(white)); + me->wy = fix(chromaticity_y(white)); + + me->rx = fix(chromaticity_x(encoding->red)); + me->ry = fix(chromaticity_y(encoding->red)); + me->gx = fix(chromaticity_x(encoding->green)); + me->gy = fix(chromaticity_y(encoding->green)); + me->bx = fix(chromaticity_x(encoding->blue)); + me->by = fix(chromaticity_y(encoding->blue)); + + modification_init(&me->this); + me->this.chunk = CHUNK_cHRM; + me->this.modify_fn = chrm_modify; + me->this.add = CHUNK_PLTE; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +typedef struct srgb_modification +{ + png_modification this; + png_byte intent; +} srgb_modification; + +static int +srgb_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* As above, ignore add and just make a new chunk */ + png_save_uint_32(pm->buffer, 1); + png_save_uint_32(pm->buffer+4, CHUNK_sRGB); + pm->buffer[8] = ((srgb_modification*)me)->intent; + return 1; +} + +static void +srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent) +{ + modification_init(&me->this); + me->this.chunk = CHUNK_sBIT; + + if (intent <= 3) /* if valid, else *delete* sRGB chunks */ + { + me->this.modify_fn = srgb_modify; + me->this.add = CHUNK_PLTE; + me->intent = intent; + } + + else + { + me->this.modify_fn = 0; + me->this.add = 0; + me->intent = 0; + } + + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +#ifdef PNG_READ_GAMMA_SUPPORTED +typedef struct sbit_modification +{ + png_modification this; + png_byte sbit; +} sbit_modification; + +static int +sbit_modify(png_modifier *pm, png_modification *me, int add) +{ + png_byte sbit = ((sbit_modification*)me)->sbit; + if (pm->bit_depth > sbit) + { + int cb = 0; + switch (pm->colour_type) + { + case 0: + cb = 1; + break; + + case 2: + case 3: + cb = 3; + break; + + case 4: + cb = 2; + break; + + case 6: + cb = 4; + break; + + default: + png_error(pm->this.pread, + "unexpected colour type in sBIT modification"); + } + + png_save_uint_32(pm->buffer, cb); + png_save_uint_32(pm->buffer+4, CHUNK_sBIT); + + while (cb > 0) + (pm->buffer+8)[--cb] = sbit; + + return 1; + } + else if (!add) + { + /* Remove the sBIT chunk */ + pm->buffer_count = pm->buffer_position = 0; + return 1; + } + else + return 0; /* do nothing */ +} + +static void +sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit) +{ + modification_init(&me->this); + me->this.chunk = CHUNK_sBIT; + me->this.modify_fn = sbit_modify; + me->this.add = CHUNK_PLTE; + me->sbit = sbit; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} +#endif /* PNG_READ_GAMMA_SUPPORTED */ +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +/***************************** STANDARD PNG FILES *****************************/ +/* Standard files - write and save standard files. */ +/* There are two basic forms of standard images. Those which attempt to have + * all the possible pixel values (not possible for 16bpp images, but a range of + * values are produced) and those which have a range of image sizes. The former + * are used for testing transforms, in particular gamma correction and bit + * reduction and increase. The latter are reserved for testing the behavior of + * libpng with respect to 'odd' image sizes - particularly small images where + * rows become 1 byte and interlace passes disappear. + * + * The first, most useful, set are the 'transform' images, the second set of + * small images are the 'size' images. + * + * The transform files are constructed with rows which fit into a 1024 byte row + * buffer. This makes allocation easier below. Further regardless of the file + * format every row has 128 pixels (giving 1024 bytes for 64bpp formats). + * + * Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed + * and with an ID derived from the colour type, bit depth and interlace type + * as above (FILEID). The width (128) and height (variable) are not stored in + * the FILEID - instead the fields are set to 0, indicating a transform file. + * + * The size files ar constructed with rows a maximum of 128 bytes wide, allowing + * a maximum width of 16 pixels (for the 64bpp case.) They also have a maximum + * height of 16 rows. The width and height are stored in the FILEID and, being + * non-zero, indicate a size file. + * + * Because the PNG filter code is typically the largest CPU consumer within + * libpng itself there is a tendency to attempt to optimize it. This results in + * special case code which needs to be validated. To cause this to happen the + * 'size' images are made to use each possible filter, in so far as this is + * possible for smaller images. + * + * For palette image (colour type 3) multiple transform images are stored with + * the same bit depth to allow testing of more colour combinations - + * particularly important for testing the gamma code because libpng uses a + * different code path for palette images. For size images a single palette is + * used. + */ + +/* Make a 'standard' palette. Because there are only 256 entries in a palette + * (maximum) this actually makes a random palette in the hope that enough tests + * will catch enough errors. (Note that the same palette isn't produced every + * time for the same test - it depends on what previous tests have been run - + * but a given set of arguments to pngvalid will always produce the same palette + * at the same test! This is why pseudo-random number generators are useful for + * testing.) + * + * The store must be open for write when this is called, otherwise an internal + * error will occur. This routine contains its own magic number seed, so the + * palettes generated don't change if there are intervening errors (changing the + * calls to the store_mark seed.) + */ +static store_palette_entry * +make_standard_palette(png_store* ps, int npalette, int do_tRNS) +{ + static png_uint_32 palette_seed[2] = { 0x87654321, 9 }; + + int i = 0; + png_byte values[256][4]; + + /* Always put in black and white plus the six primary and secondary colors. + */ + for (; i<8; ++i) + { + values[i][1] = (png_byte)((i&1) ? 255U : 0U); + values[i][2] = (png_byte)((i&2) ? 255U : 0U); + values[i][3] = (png_byte)((i&4) ? 255U : 0U); + } + + /* Then add 62 grays (one quarter of the remaining 256 slots). */ + { + int j = 0; + png_byte random_bytes[4]; + png_byte need[256]; + + need[0] = 0; /*got black*/ + memset(need+1, 1, (sizeof need)-2); /*need these*/ + need[255] = 0; /*but not white*/ + + while (i<70) + { + png_byte b; + + if (j==0) + { + make_four_random_bytes(palette_seed, random_bytes); + j = 4; + } + + b = random_bytes[--j]; + if (need[b]) + { + values[i][1] = b; + values[i][2] = b; + values[i++][3] = b; + } + } + } + + /* Finally add 192 colors at random - don't worry about matches to things we + * already have, chance is less than 1/65536. Don't worry about grays, + * chance is the same, so we get a duplicate or extra gray less than 1 time + * in 170. + */ + for (; i<256; ++i) + make_four_random_bytes(palette_seed, values[i]); + + /* Fill in the alpha values in the first byte. Just use all possible values + * (0..255) in an apparently random order: + */ + { + store_palette_entry *palette; + png_byte selector[4]; + + make_four_random_bytes(palette_seed, selector); + + if (do_tRNS) + for (i=0; i<256; ++i) + values[i][0] = (png_byte)(i ^ selector[0]); + + else + for (i=0; i<256; ++i) + values[i][0] = 255; /* no transparency/tRNS chunk */ + + /* 'values' contains 256 ARGB values, but we only need 'npalette'. + * 'npalette' will always be a power of 2: 2, 4, 16 or 256. In the low + * bit depth cases select colors at random, else it is difficult to have + * a set of low bit depth palette test with any chance of a reasonable + * range of colors. Do this by randomly permuting values into the low + * 'npalette' entries using an XOR mask generated here. This also + * permutes the npalette == 256 case in a potentially useful way (there is + * no relationship between palette index and the color value therein!) + */ + palette = store_write_palette(ps, npalette); + + for (i=0; i<npalette; ++i) + { + palette[i].alpha = values[i ^ selector[1]][0]; + palette[i].red = values[i ^ selector[1]][1]; + palette[i].green = values[i ^ selector[1]][2]; + palette[i].blue = values[i ^ selector[1]][3]; + } + + return palette; + } +} + +/* Initialize a standard palette on a write stream. The 'do_tRNS' argument + * indicates whether or not to also set the tRNS chunk. + */ +/* TODO: the png_structp here can probably be 'const' in the future */ +static void +init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette, + int do_tRNS) +{ + store_palette_entry *ppal = make_standard_palette(ps, npalette, do_tRNS); + + { + int i; + png_color palette[256]; + + /* Set all entries to detect overread errors. */ + for (i=0; i<npalette; ++i) + { + palette[i].red = ppal[i].red; + palette[i].green = ppal[i].green; + palette[i].blue = ppal[i].blue; + } + + /* Just in case fill in the rest with detectable values: */ + for (; i<256; ++i) + palette[i].red = palette[i].green = palette[i].blue = 42; + + png_set_PLTE(pp, pi, palette, npalette); + } + + if (do_tRNS) + { + int i, j; + png_byte tRNS[256]; + + /* Set all the entries, but skip trailing opaque entries */ + for (i=j=0; i<npalette; ++i) + if ((tRNS[i] = ppal[i].alpha) < 255) + j = i+1; + + /* Fill in the remainder with a detectable value: */ + for (; i<256; ++i) + tRNS[i] = 24; + +# ifdef PNG_WRITE_tRNS_SUPPORTED + if (j > 0) + png_set_tRNS(pp, pi, tRNS, j, 0/*color*/); +# endif + } +} + +/* The number of passes is related to the interlace type. There was no libpng + * API to determine this prior to 1.5, so we need an inquiry function: + */ +static int +npasses_from_interlace_type(png_const_structp pp, int interlace_type) +{ + switch (interlace_type) + { + default: + png_error(pp, "invalid interlace type"); + + case PNG_INTERLACE_NONE: + return 1; + + case PNG_INTERLACE_ADAM7: + return PNG_INTERLACE_ADAM7_PASSES; + } +} + +static unsigned int +bit_size(png_const_structp pp, png_byte colour_type, png_byte bit_depth) +{ + switch (colour_type) + { + default: png_error(pp, "invalid color type"); + + case 0: return bit_depth; + + case 2: return 3*bit_depth; + + case 3: return bit_depth; + + case 4: return 2*bit_depth; + + case 6: return 4*bit_depth; + } +} + +#define TRANSFORM_WIDTH 128U +#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U) +#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */ +#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */ +#define SIZE_HEIGHTMAX 16 /* Maximum range of size images */ + +static size_t +transform_rowsize(png_const_structp pp, png_byte colour_type, + png_byte bit_depth) +{ + return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8; +} + +/* transform_width(pp, colour_type, bit_depth) current returns the same number + * every time, so just use a macro: + */ +#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH + +static png_uint_32 +transform_height(png_const_structp pp, png_byte colour_type, png_byte bit_depth) +{ + switch (bit_size(pp, colour_type, bit_depth)) + { + case 1: + case 2: + case 4: + return 1; /* Total of 128 pixels */ + + case 8: + return 2; /* Total of 256 pixels/bytes */ + + case 16: + return 512; /* Total of 65536 pixels */ + + case 24: + case 32: + return 512; /* 65536 pixels */ + + case 48: + case 64: + return 2048;/* 4 x 65536 pixels. */ +# define TRANSFORM_HEIGHTMAX 2048 + + default: + return 0; /* Error, will be caught later */ + } +} + +#ifdef PNG_READ_SUPPORTED +/* The following can only be defined here, now we have the definitions + * of the transform image sizes. + */ +static png_uint_32 +standard_width(png_const_structp pp, png_uint_32 id) +{ + png_uint_32 width = WIDTH_FROM_ID(id); + UNUSED(pp) + + if (width == 0) + width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + + return width; +} + +static png_uint_32 +standard_height(png_const_structp pp, png_uint_32 id) +{ + png_uint_32 height = HEIGHT_FROM_ID(id); + + if (height == 0) + height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + + return height; +} + +static png_uint_32 +standard_rowsize(png_const_structp pp, png_uint_32 id) +{ + png_uint_32 width = standard_width(pp, id); + + /* This won't overflow: */ + width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + return (width + 7) / 8; +} +#endif /* PNG_READ_SUPPORTED */ + +static void +transform_row(png_const_structp pp, png_byte buffer[TRANSFORM_ROWMAX], + png_byte colour_type, png_byte bit_depth, png_uint_32 y) +{ + png_uint_32 v = y << 7; + png_uint_32 i = 0; + + switch (bit_size(pp, colour_type, bit_depth)) + { + case 1: + while (i<128/8) buffer[i] = (png_byte)(v & 0xff), v += 17, ++i; + return; + + case 2: + while (i<128/4) buffer[i] = (png_byte)(v & 0xff), v += 33, ++i; + return; + + case 4: + while (i<128/2) buffer[i] = (png_byte)(v & 0xff), v += 65, ++i; + return; + + case 8: + /* 256 bytes total, 128 bytes in each row set as follows: */ + while (i<128) buffer[i] = (png_byte)(v & 0xff), ++v, ++i; + return; + + case 16: + /* Generate all 65536 pixel values in order, which includes the 8 bit + * GA case as well as the 16 bit G case. + */ + while (i<128) + { + buffer[2*i] = (png_byte)((v>>8) & 0xff); + buffer[2*i+1] = (png_byte)(v & 0xff); + ++v; + ++i; + } + + return; + + case 24: + /* 65535 pixels, but rotate the values. */ + while (i<128) + { + /* Three bytes per pixel, r, g, b, make b by r^g */ + buffer[3*i+0] = (png_byte)((v >> 8) & 0xff); + buffer[3*i+1] = (png_byte)(v & 0xff); + buffer[3*i+2] = (png_byte)(((v >> 8) ^ v) & 0xff); + ++v; + ++i; + } + + return; + + case 32: + /* 65535 pixels, r, g, b, a; just replicate */ + while (i<128) + { + buffer[4*i+0] = (png_byte)((v >> 8) & 0xff); + buffer[4*i+1] = (png_byte)(v & 0xff); + buffer[4*i+2] = (png_byte)((v >> 8) & 0xff); + buffer[4*i+3] = (png_byte)(v & 0xff); + ++v; + ++i; + } + + return; + + case 48: + /* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at + * each pixel, g increase by 257 (0x101) and 'b' by 0x1111: + */ + while (i<128) + { + png_uint_32 t = v++; + buffer[6*i+0] = (png_byte)((t >> 8) & 0xff); + buffer[6*i+1] = (png_byte)(t & 0xff); + t *= 257; + buffer[6*i+2] = (png_byte)((t >> 8) & 0xff); + buffer[6*i+3] = (png_byte)(t & 0xff); + t *= 17; + buffer[6*i+4] = (png_byte)((t >> 8) & 0xff); + buffer[6*i+5] = (png_byte)(t & 0xff); + ++i; + } + + return; + + case 64: + /* As above in the 32 bit case. */ + while (i<128) + { + png_uint_32 t = v++; + buffer[8*i+0] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+1] = (png_byte)(t & 0xff); + buffer[8*i+4] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+5] = (png_byte)(t & 0xff); + t *= 257; + buffer[8*i+2] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+3] = (png_byte)(t & 0xff); + buffer[8*i+6] = (png_byte)((t >> 8) & 0xff); + buffer[8*i+7] = (png_byte)(t & 0xff); + ++i; + } + return; + + default: + break; + } + + png_error(pp, "internal error"); +} + +/* This is just to do the right cast - could be changed to a function to check + * 'bd' but there isn't much point. + */ +#define DEPTH(bd) ((png_byte)(1U << (bd))) + +/* This is just a helper for compiling on minimal systems with no write + * interlacing support. If there is no write interlacing we can't generate test + * cases with interlace: + */ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +# define INTERLACE_LAST PNG_INTERLACE_LAST +# define check_interlace_type(type) ((void)(type)) +#else +# define INTERLACE_LAST (PNG_INTERLACE_NONE+1) +# define png_set_interlace_handling(a) (1) + +static void +check_interlace_type(int PNG_CONST interlace_type) +{ + if (interlace_type != PNG_INTERLACE_NONE) + { + /* This is an internal error - --interlace tests should be skipped, not + * attempted. + */ + fprintf(stderr, "pngvalid: no interlace support\n"); + exit(99); + } +} +#endif + +/* Make a standardized image given a an image colour type, bit depth and + * interlace type. The standard images have a very restricted range of + * rows and heights and are used for testing transforms rather than image + * layout details. See make_size_images below for a way to make images + * that test odd sizes along with the libpng interlace handling. + */ +static void +make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, + png_byte PNG_CONST bit_depth, unsigned int palette_number, + int interlace_type, png_const_charp name) +{ + context(ps, fault); + + check_interlace_type(interlace_type); + + Try + { + png_infop pi; + png_structp pp = set_store_for_write(ps, &pi, name); + png_uint_32 h; + + /* In the event of a problem return control to the Catch statement below + * to do the clean up - it is not possible to 'return' directly from a Try + * block. + */ + if (pp == NULL) + Throw ps; + + h = transform_height(pp, colour_type, bit_depth); + + png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), h, + bit_depth, colour_type, interlace_type, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + +#ifdef PNG_TEXT_SUPPORTED +# if defined(PNG_READ_zTXt_SUPPORTED) && defined(PNG_WRITE_zTXt_SUPPORTED) +# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_zTXt +# else +# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_NONE +# endif + { + static char key[] = "image name"; /* must be writeable */ + size_t pos; + png_text text; + char copy[FILE_NAME_SIZE]; + + /* Use a compressed text string to test the correct interaction of text + * compression and IDAT compression. + */ + text.compression = TEXT_COMPRESSION; + text.key = key; + /* Yuck: the text must be writable! */ + pos = safecat(copy, sizeof copy, 0, ps->wname); + text.text = copy; + text.text_length = pos; + text.itxt_length = 0; + text.lang = 0; + text.lang_key = 0; + + png_set_text(pp, pi, &text, 1); + } +#endif + + if (colour_type == 3) /* palette */ + init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/); + + png_write_info(pp, pi); + + if (png_get_rowbytes(pp, pi) != + transform_rowsize(pp, colour_type, bit_depth)) + png_error(pp, "row size incorrect"); + + else + { + /* Somewhat confusingly this must be called *after* png_write_info + * because if it is called before, the information in *pp has not been + * updated to reflect the interlaced image. + */ + int npasses = png_set_interlace_handling(pp); + int pass; + + if (npasses != npasses_from_interlace_type(pp, interlace_type)) + png_error(pp, "write: png_set_interlace_handling failed"); + + for (pass=0; pass<npasses; ++pass) + { + png_uint_32 y; + + for (y=0; y<h; ++y) + { + png_byte buffer[TRANSFORM_ROWMAX]; + + transform_row(pp, buffer, colour_type, bit_depth, y); + png_write_row(pp, buffer); + } + } + } + +#ifdef PNG_TEXT_SUPPORTED + { + static char key[] = "end marker"; + static char comment[] = "end"; + png_text text; + + /* Use a compressed text string to test the correct interaction of text + * compression and IDAT compression. + */ + text.compression = TEXT_COMPRESSION; + text.key = key; + text.text = comment; + text.text_length = (sizeof comment)-1; + text.itxt_length = 0; + text.lang = 0; + text.lang_key = 0; + + png_set_text(pp, pi, &text, 1); + } +#endif + + png_write_end(pp, pi); + + /* And store this under the appropriate id, then clean up. */ + store_storefile(ps, FILEID(colour_type, bit_depth, palette_number, + interlace_type, 0, 0, 0)); + + store_write_reset(ps); + } + + Catch(fault) + { + /* Use the png_store returned by the exception. This may help the compiler + * because 'ps' is not used in this branch of the setjmp. Note that fault + * and ps will always be the same value. + */ + store_write_reset(fault); + } +} + +static void +make_transform_images(png_store *ps) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + unsigned int palette_number = 0; + + /* This is in case of errors. */ + safecat(ps->test, sizeof ps->test, 0, "make standard images"); + + /* Use next_format to enumerate all the combinations we test, including + * generating multiple low bit depth palette images. + */ + while (next_format(&colour_type, &bit_depth, &palette_number, 0)) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < INTERLACE_LAST; ++interlace_type) + { + char name[FILE_NAME_SIZE]; + + standard_name(name, sizeof name, 0, colour_type, bit_depth, + palette_number, interlace_type, 0, 0, 0); + make_transform_image(ps, colour_type, bit_depth, palette_number, + interlace_type, name); + } + } +} + +/* The following two routines use the PNG interlace support macros from + * png.h to interlace or deinterlace rows. + */ +static void +interlace_row(png_bytep buffer, png_const_bytep imageRow, + unsigned int pixel_size, png_uint_32 w, int pass) +{ + png_uint_32 xin, xout, xstep; + + /* Note that this can, trivially, be optimized to a memcpy on pass 7, the + * code is presented this way to make it easier to understand. In practice + * consult the code in the libpng source to see other ways of doing this. + */ + xin = PNG_PASS_START_COL(pass); + xstep = 1U<<PNG_PASS_COL_SHIFT(pass); + + for (xout=0; xin<w; xin+=xstep) + { + pixel_copy(buffer, xout, imageRow, xin, pixel_size); + ++xout; + } +} + +#ifdef PNG_READ_SUPPORTED +static void +deinterlace_row(png_bytep buffer, png_const_bytep row, + unsigned int pixel_size, png_uint_32 w, int pass) +{ + /* The inverse of the above, 'row' is part of row 'y' of the output image, + * in 'buffer'. The image is 'w' wide and this is pass 'pass', distribute + * the pixels of row into buffer and return the number written (to allow + * this to be checked). + */ + png_uint_32 xin, xout, xstep; + + xout = PNG_PASS_START_COL(pass); + xstep = 1U<<PNG_PASS_COL_SHIFT(pass); + + for (xin=0; xout<w; xout+=xstep) + { + pixel_copy(buffer, xout, row, xin, pixel_size); + ++xin; + } +} +#endif /* PNG_READ_SUPPORTED */ + +/* Build a single row for the 'size' test images; this fills in only the + * first bit_width bits of the sample row. + */ +static void +size_row(png_byte buffer[SIZE_ROWMAX], png_uint_32 bit_width, png_uint_32 y) +{ + /* height is in the range 1 to 16, so: */ + y = ((y & 1) << 7) + ((y & 2) << 6) + ((y & 4) << 5) + ((y & 8) << 4); + /* the following ensures bits are set in small images: */ + y ^= 0xA5; + + while (bit_width >= 8) + *buffer++ = (png_byte)y++, bit_width -= 8; + + /* There may be up to 7 remaining bits, these go in the most significant + * bits of the byte. + */ + if (bit_width > 0) + { + png_uint_32 mask = (1U<<(8-bit_width))-1; + *buffer = (png_byte)((*buffer & mask) | (y & ~mask)); + } +} + +static void +make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, + png_byte PNG_CONST bit_depth, int PNG_CONST interlace_type, + png_uint_32 PNG_CONST w, png_uint_32 PNG_CONST h, + int PNG_CONST do_interlace) +{ + context(ps, fault); + + /* At present libpng does not support the write of an interlaced image unless + * PNG_WRITE_INTERLACING_SUPPORTED, even with do_interlace so the code here + * does the pixel interlace itself, so: + */ + check_interlace_type(interlace_type); + + Try + { + png_infop pi; + png_structp pp; + unsigned int pixel_size; + + /* Make a name and get an appropriate id for the store: */ + char name[FILE_NAME_SIZE]; + PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/, + interlace_type, w, h, do_interlace); + + standard_name_from_id(name, sizeof name, 0, id); + pp = set_store_for_write(ps, &pi, name); + + /* In the event of a problem return control to the Catch statement below + * to do the clean up - it is not possible to 'return' directly from a Try + * block. + */ + if (pp == NULL) + Throw ps; + + png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + +#ifdef PNG_TEXT_SUPPORTED + { + static char key[] = "image name"; /* must be writeable */ + size_t pos; + png_text text; + char copy[FILE_NAME_SIZE]; + + /* Use a compressed text string to test the correct interaction of text + * compression and IDAT compression. + */ + text.compression = TEXT_COMPRESSION; + text.key = key; + /* Yuck: the text must be writable! */ + pos = safecat(copy, sizeof copy, 0, ps->wname); + text.text = copy; + text.text_length = pos; + text.itxt_length = 0; + text.lang = 0; + text.lang_key = 0; + + png_set_text(pp, pi, &text, 1); + } +#endif + + if (colour_type == 3) /* palette */ + init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); + + png_write_info(pp, pi); + + /* Calculate the bit size, divide by 8 to get the byte size - this won't + * overflow because we know the w values are all small enough even for + * a system where 'unsigned int' is only 16 bits. + */ + pixel_size = bit_size(pp, colour_type, bit_depth); + if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8) + png_error(pp, "row size incorrect"); + + else + { + int npasses = npasses_from_interlace_type(pp, interlace_type); + png_uint_32 y; + int pass; +# ifdef PNG_WRITE_FILTER_SUPPORTED + int nfilter = PNG_FILTER_VALUE_LAST; +# endif + png_byte image[16][SIZE_ROWMAX]; + + /* To help consistent error detection make the parts of this buffer + * that aren't set below all '1': + */ + memset(image, 0xff, sizeof image); + + if (!do_interlace && npasses != png_set_interlace_handling(pp)) + png_error(pp, "write: png_set_interlace_handling failed"); + + /* Prepare the whole image first to avoid making it 7 times: */ + for (y=0; y<h; ++y) + size_row(image[y], w * pixel_size, y); + + for (pass=0; pass<npasses; ++pass) + { + /* The following two are for checking the macros: */ + PNG_CONST png_uint_32 wPass = PNG_PASS_COLS(w, pass); + + /* If do_interlace is set we don't call png_write_row for every + * row because some of them are empty. In fact, for a 1x1 image, + * most of them are empty! + */ + for (y=0; y<h; ++y) + { + png_const_bytep row = image[y]; + png_byte tempRow[SIZE_ROWMAX]; + + /* If do_interlace *and* the image is interlaced we + * need a reduced interlace row; this may be reduced + * to empty. + */ + if (do_interlace && interlace_type == PNG_INTERLACE_ADAM7) + { + /* The row must not be written if it doesn't exist, notice + * that there are two conditions here, either the row isn't + * ever in the pass or the row would be but isn't wide + * enough to contribute any pixels. In fact the wPass test + * can be used to skip the whole y loop in this case. + */ + if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && wPass > 0) + { + /* Set to all 1's for error detection (libpng tends to + * set unset things to 0). + */ + memset(tempRow, 0xff, sizeof tempRow); + interlace_row(tempRow, row, pixel_size, w, pass); + row = tempRow; + } + else + continue; + } + +# ifdef PNG_WRITE_FILTER_SUPPORTED + /* Only get to here if the row has some pixels in it, set the + * filters to 'all' for the very first row and thereafter to a + * single filter. It isn't well documented, but png_set_filter + * does accept a filter number (per the spec) as well as a bit + * mask. + * + * The apparent wackiness of decrementing nfilter rather than + * incrementing is so that Paeth gets used in all images bigger + * than 1 row - it's the tricky one. + */ + png_set_filter(pp, 0/*method*/, + nfilter >= PNG_FILTER_VALUE_LAST ? PNG_ALL_FILTERS : nfilter); + + if (nfilter-- == 0) + nfilter = PNG_FILTER_VALUE_LAST-1; +# endif + + png_write_row(pp, row); + } + } + } + +#ifdef PNG_TEXT_SUPPORTED + { + static char key[] = "end marker"; + static char comment[] = "end"; + png_text text; + + /* Use a compressed text string to test the correct interaction of text + * compression and IDAT compression. + */ + text.compression = TEXT_COMPRESSION; + text.key = key; + text.text = comment; + text.text_length = (sizeof comment)-1; + text.itxt_length = 0; + text.lang = 0; + text.lang_key = 0; + + png_set_text(pp, pi, &text, 1); + } +#endif + + png_write_end(pp, pi); + + /* And store this under the appropriate id, then clean up. */ + store_storefile(ps, id); + + store_write_reset(ps); + } + + Catch(fault) + { + /* Use the png_store returned by the exception. This may help the compiler + * because 'ps' is not used in this branch of the setjmp. Note that fault + * and ps will always be the same value. + */ + store_write_reset(fault); + } +} + +static void +make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo, + int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + png_uint_32 width; + + for (width = 1; width <= 16; ++width) + { + png_uint_32 height; + + for (height = 1; height <= 16; ++height) + { + /* The four combinations of DIY interlace and interlace or not - + * no interlace + DIY should be identical to no interlace with + * libpng doing it. + */ + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, + width, height, 0); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, + width, height, 1); +# ifdef PNG_WRITE_INTERLACING_SUPPORTED + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, + width, height, 0); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, + width, height, 1); +# endif + } + } + } +} + +static void +make_size_images(png_store *ps) +{ + /* This is in case of errors. */ + safecat(ps->test, sizeof ps->test, 0, "make size images"); + + /* Arguments are colour_type, low bit depth, high bit depth + */ + make_size(ps, 0, 0, WRITE_BDHI); + make_size(ps, 2, 3, WRITE_BDHI); + make_size(ps, 3, 0, 3 /*palette: max 8 bits*/); + make_size(ps, 4, 3, WRITE_BDHI); + make_size(ps, 6, 3, WRITE_BDHI); +} + +#ifdef PNG_READ_SUPPORTED +/* Return a row based on image id and 'y' for checking: */ +static void +standard_row(png_const_structp pp, png_byte std[STANDARD_ROWMAX], + png_uint_32 id, png_uint_32 y) +{ + if (WIDTH_FROM_ID(id) == 0) + transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y); + else + size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id), + DEPTH_FROM_ID(id)), y); +} +#endif /* PNG_READ_SUPPORTED */ + +/* Tests - individual test cases */ +/* Like 'make_standard' but errors are deliberately introduced into the calls + * to ensure that they get detected - it should not be possible to write an + * invalid image with libpng! + */ +/* TODO: the 'set' functions can probably all be made to take a + * png_const_structp rather than a modifiable one. + */ +#ifdef PNG_WARNINGS_SUPPORTED +static void +sBIT0_error_fn(png_structp pp, png_infop pi) +{ + /* 0 is invalid... */ + png_color_8 bad; + bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0; + png_set_sBIT(pp, pi, &bad); +} + +static void +sBIT_error_fn(png_structp pp, png_infop pi) +{ + png_byte bit_depth; + png_color_8 bad; + + if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE) + bit_depth = 8; + + else + bit_depth = png_get_bit_depth(pp, pi); + + /* Now we know the bit depth we can easily generate an invalid sBIT entry */ + bad.red = bad.green = bad.blue = bad.gray = bad.alpha = + (png_byte)(bit_depth+1); + png_set_sBIT(pp, pi, &bad); +} + +static PNG_CONST struct +{ + void (*fn)(png_structp, png_infop); + PNG_CONST char *msg; + unsigned int warning :1; /* the error is a warning... */ +} error_test[] = + { + /* no warnings makes these errors undetectable. */ + { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 }, + { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 }, + }; + +static void +make_error(png_store* volatile psIn, png_byte PNG_CONST colour_type, + png_byte bit_depth, int interlace_type, int test, png_const_charp name) +{ + png_store * volatile ps = psIn; + + context(ps, fault); + + check_interlace_type(interlace_type); + + Try + { + png_structp pp; + png_infop pi; + + pp = set_store_for_write(ps, &pi, name); + + if (pp == NULL) + Throw ps; + + png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), + transform_height(pp, colour_type, bit_depth), bit_depth, colour_type, + interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (colour_type == 3) /* palette */ + init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); + + /* Time for a few errors; these are in various optional chunks, the + * standard tests test the standard chunks pretty well. + */ +# define exception__prev exception_prev_1 +# define exception__env exception_env_1 + Try + { + /* Expect this to throw: */ + ps->expect_error = !error_test[test].warning; + ps->expect_warning = error_test[test].warning; + ps->saw_warning = 0; + error_test[test].fn(pp, pi); + + /* Normally the error is only detected here: */ + png_write_info(pp, pi); + + /* And handle the case where it was only a warning: */ + if (ps->expect_warning && ps->saw_warning) + Throw ps; + + /* If we get here there is a problem, we have success - no error or + * no warning - when we shouldn't have success. Log an error. + */ + store_log(ps, pp, error_test[test].msg, 1 /*error*/); + } + + Catch (fault) + ps = fault; /* expected exit, make sure ps is not clobbered */ +#undef exception__prev +#undef exception__env + + /* And clear these flags */ + ps->expect_error = 0; + ps->expect_warning = 0; + + /* Now write the whole image, just to make sure that the detected, or + * undetected, errro has not created problems inside libpng. + */ + if (png_get_rowbytes(pp, pi) != + transform_rowsize(pp, colour_type, bit_depth)) + png_error(pp, "row size incorrect"); + + else + { + png_uint_32 h = transform_height(pp, colour_type, bit_depth); + int npasses = png_set_interlace_handling(pp); + int pass; + + if (npasses != npasses_from_interlace_type(pp, interlace_type)) + png_error(pp, "write: png_set_interlace_handling failed"); + + for (pass=0; pass<npasses; ++pass) + { + png_uint_32 y; + + for (y=0; y<h; ++y) + { + png_byte buffer[TRANSFORM_ROWMAX]; + + transform_row(pp, buffer, colour_type, bit_depth, y); + png_write_row(pp, buffer); + } + } + } + + png_write_end(pp, pi); + + /* The following deletes the file that was just written. */ + store_write_reset(ps); + } + + Catch(fault) + { + store_write_reset(fault); + } +} + +static int +make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < INTERLACE_LAST; ++interlace_type) + { + unsigned int test; + char name[FILE_NAME_SIZE]; + + standard_name(name, sizeof name, 0, colour_type, 1<<bdlo, 0, + interlace_type, 0, 0, 0); + + for (test=0; test<ARRAY_SIZE(error_test); ++test) + { + make_error(&pm->this, colour_type, DEPTH(bdlo), interlace_type, + test, name); + + if (fail(pm)) + return 0; + } + } + } + + return 1; /* keep going */ +} +#endif /* PNG_WARNINGS_SUPPORTED */ + +static void +perform_error_test(png_modifier *pm) +{ +#ifdef PNG_WARNINGS_SUPPORTED /* else there are no cases that work! */ + /* Need to do this here because we just write in this test. */ + safecat(pm->this.test, sizeof pm->this.test, 0, "error test"); + + if (!make_errors(pm, 0, 0, WRITE_BDHI)) + return; + + if (!make_errors(pm, 2, 3, WRITE_BDHI)) + return; + + if (!make_errors(pm, 3, 0, 3)) + return; + + if (!make_errors(pm, 4, 3, WRITE_BDHI)) + return; + + if (!make_errors(pm, 6, 3, WRITE_BDHI)) + return; +#else + UNUSED(pm) +#endif +} + +/* This is just to validate the internal PNG formatting code - if this fails + * then the warning messages the library outputs will probably be garbage. + */ +static void +perform_formatting_test(png_store *volatile ps) +{ +#ifdef PNG_TIME_RFC1123_SUPPORTED + /* The handle into the formatting code is the RFC1123 support; this test does + * nothing if that is compiled out. + */ + context(ps, fault); + + Try + { + png_const_charp correct = "29 Aug 2079 13:53:60 +0000"; + png_const_charp result; +# if PNG_LIBPNG_VER >= 10600 + char timestring[29]; +# endif + png_structp pp; + png_time pt; + + pp = set_store_for_write(ps, NULL, "libpng formatting test"); + + if (pp == NULL) + Throw ps; + + + /* Arbitrary settings: */ + pt.year = 2079; + pt.month = 8; + pt.day = 29; + pt.hour = 13; + pt.minute = 53; + pt.second = 60; /* a leap second */ + +# if PNG_LIBPNG_VER < 10600 + result = png_convert_to_rfc1123(pp, &pt); +# else + if (png_convert_to_rfc1123_buffer(timestring, &pt)) + result = timestring; + + else + result = NULL; +# endif + + if (result == NULL) + png_error(pp, "png_convert_to_rfc1123 failed"); + + if (strcmp(result, correct) != 0) + { + size_t pos = 0; + char msg[128]; + + pos = safecat(msg, sizeof msg, pos, "png_convert_to_rfc1123("); + pos = safecat(msg, sizeof msg, pos, correct); + pos = safecat(msg, sizeof msg, pos, ") returned: '"); + pos = safecat(msg, sizeof msg, pos, result); + pos = safecat(msg, sizeof msg, pos, "'"); + + png_error(pp, msg); + } + + store_write_reset(ps); + } + + Catch(fault) + { + store_write_reset(fault); + } +#else + UNUSED(ps) +#endif +} + +#ifdef PNG_READ_SUPPORTED +/* Because we want to use the same code in both the progressive reader and the + * sequential reader it is necessary to deal with the fact that the progressive + * reader callbacks only have one parameter (png_get_progressive_ptr()), so this + * must contain all the test parameters and all the local variables directly + * accessible to the sequential reader implementation. + * + * The technique adopted is to reinvent part of what Dijkstra termed a + * 'display'; an array of pointers to the stack frames of enclosing functions so + * that a nested function definition can access the local (C auto) variables of + * the functions that contain its definition. In fact C provides the first + * pointer (the local variables - the stack frame pointer) and the last (the + * global variables - the BCPL global vector typically implemented as global + * addresses), this code requires one more pointer to make the display - the + * local variables (and function call parameters) of the function that actually + * invokes either the progressive or sequential reader. + * + * Perhaps confusingly this technique is confounded with classes - the + * 'standard_display' defined here is sub-classed as the 'gamma_display' below. + * A gamma_display is a standard_display, taking advantage of the ANSI-C + * requirement that the pointer to the first member of a structure must be the + * same as the pointer to the structure. This allows us to reuse standard_ + * functions in the gamma test code; something that could not be done with + * nested functions! + */ +typedef struct standard_display +{ + png_store* ps; /* Test parameters (passed to the function) */ + png_byte colour_type; + png_byte bit_depth; + png_byte red_sBIT; /* Input data sBIT values. */ + png_byte green_sBIT; + png_byte blue_sBIT; + png_byte alpha_sBIT; + png_byte interlace_type; + png_byte filler; /* Output has a filler */ + png_uint_32 id; /* Calculated file ID */ + png_uint_32 w; /* Width of image */ + png_uint_32 h; /* Height of image */ + int npasses; /* Number of interlaced passes */ + png_uint_32 pixel_size; /* Width of one pixel in bits */ + png_uint_32 bit_width; /* Width of output row in bits */ + size_t cbRow; /* Bytes in a row of the output image */ + int do_interlace; /* Do interlacing internally */ + int is_transparent; /* Transparency information was present. */ + int speed; /* Doing a speed test */ + int use_update_info;/* Call update_info, not start_image */ + struct + { + png_uint_16 red; + png_uint_16 green; + png_uint_16 blue; + } transparent; /* The transparent color, if set. */ + int npalette; /* Number of entries in the palette. */ + store_palette + palette; +} standard_display; + +static void +standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id, + int do_interlace, int use_update_info) +{ + memset(dp, 0, sizeof *dp); + + dp->ps = ps; + dp->colour_type = COL_FROM_ID(id); + dp->bit_depth = DEPTH_FROM_ID(id); + if (dp->bit_depth < 1 || dp->bit_depth > 16) + internal_error(ps, "internal: bad bit depth"); + if (dp->colour_type == 3) + dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8; + else + dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = + dp->bit_depth; + dp->interlace_type = INTERLACE_FROM_ID(id); + check_interlace_type(dp->interlace_type); + dp->id = id; + /* All the rest are filled in after the read_info: */ + dp->w = 0; + dp->h = 0; + dp->npasses = 0; + dp->pixel_size = 0; + dp->bit_width = 0; + dp->cbRow = 0; + dp->do_interlace = do_interlace; + dp->is_transparent = 0; + dp->speed = ps->speed; + dp->use_update_info = use_update_info; + dp->npalette = 0; + /* Preset the transparent color to black: */ + memset(&dp->transparent, 0, sizeof dp->transparent); + /* Preset the palette to full intensity/opaque througout: */ + memset(dp->palette, 0xff, sizeof dp->palette); +} + +/* Initialize the palette fields - this must be done later because the palette + * comes from the particular png_store_file that is selected. + */ +static void +standard_palette_init(standard_display *dp) +{ + store_palette_entry *palette = store_current_palette(dp->ps, &dp->npalette); + + /* The remaining entries remain white/opaque. */ + if (dp->npalette > 0) + { + int i = dp->npalette; + memcpy(dp->palette, palette, i * sizeof *palette); + + /* Check for a non-opaque palette entry: */ + while (--i >= 0) + if (palette[i].alpha < 255) + break; + +# ifdef __GNUC__ + /* GCC can't handle the more obviously optimizable version. */ + if (i >= 0) + dp->is_transparent = 1; + else + dp->is_transparent = 0; +# else + dp->is_transparent = (i >= 0); +# endif + } +} + +/* Utility to read the palette from the PNG file and convert it into + * store_palette format. This returns 1 if there is any transparency in the + * palette (it does not check for a transparent colour in the non-palette case.) + */ +static int +read_palette(store_palette palette, int *npalette, png_const_structp pp, + png_infop pi) +{ + png_colorp pal; + png_bytep trans_alpha; + int num; + + pal = 0; + *npalette = -1; + + if (png_get_PLTE(pp, pi, &pal, npalette) & PNG_INFO_PLTE) + { + int i = *npalette; + + if (i <= 0 || i > 256) + png_error(pp, "validate: invalid PLTE count"); + + while (--i >= 0) + { + palette[i].red = pal[i].red; + palette[i].green = pal[i].green; + palette[i].blue = pal[i].blue; + } + + /* Mark the remainder of the entries with a flag value (other than + * white/opaque which is the flag value stored above.) + */ + memset(palette + *npalette, 126, (256-*npalette) * sizeof *palette); + } + + else /* !png_get_PLTE */ + { + if (*npalette != (-1)) + png_error(pp, "validate: invalid PLTE result"); + /* But there is no palette, so record this: */ + *npalette = 0; + memset(palette, 113, sizeof (store_palette)); + } + + trans_alpha = 0; + num = 2; /* force error below */ + if ((png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) != 0 && + (trans_alpha != NULL || num != 1/*returns 1 for a transparent color*/) && + /* Oops, if a palette tRNS gets expanded png_read_update_info (at least so + * far as 1.5.4) does not remove the trans_alpha pointer, only num_trans, + * so in the above call we get a success, we get a pointer (who knows what + * to) and we get num_trans == 0: + */ + !(trans_alpha != NULL && num == 0)) /* TODO: fix this in libpng. */ + { + int i; + + /* Any of these are crash-worthy - given the implementation of + * png_get_tRNS up to 1.5 an app won't crash if it just checks the + * result above and fails to check that the variables it passed have + * actually been filled in! Note that if the app were to pass the + * last, png_color_16p, variable too it couldn't rely on this. + */ + if (trans_alpha == NULL || num <= 0 || num > 256 || num > *npalette) + png_error(pp, "validate: unexpected png_get_tRNS (palette) result"); + + for (i=0; i<num; ++i) + palette[i].alpha = trans_alpha[i]; + + for (num=*npalette; i<num; ++i) + palette[i].alpha = 255; + + for (; i<256; ++i) + palette[i].alpha = 33; /* flag value */ + + return 1; /* transparency */ + } + + else + { + /* No palette transparency - just set the alpha channel to opaque. */ + int i; + + for (i=0, num=*npalette; i<num; ++i) + palette[i].alpha = 255; + + for (; i<256; ++i) + palette[i].alpha = 55; /* flag value */ + + return 0; /* no transparency */ + } +} + +/* Utility to validate the palette if it should not have changed (the + * non-transform case). + */ +static void +standard_palette_validate(standard_display *dp, png_const_structp pp, + png_infop pi) +{ + int npalette; + store_palette palette; + + if (read_palette(palette, &npalette, pp, pi) != dp->is_transparent) + png_error(pp, "validate: palette transparency changed"); + + if (npalette != dp->npalette) + { + size_t pos = 0; + char msg[64]; + + pos = safecat(msg, sizeof msg, pos, "validate: palette size changed: "); + pos = safecatn(msg, sizeof msg, pos, dp->npalette); + pos = safecat(msg, sizeof msg, pos, " -> "); + pos = safecatn(msg, sizeof msg, pos, npalette); + png_error(pp, msg); + } + + { + int i = npalette; /* npalette is aliased */ + + while (--i >= 0) + if (palette[i].red != dp->palette[i].red || + palette[i].green != dp->palette[i].green || + palette[i].blue != dp->palette[i].blue || + palette[i].alpha != dp->palette[i].alpha) + png_error(pp, "validate: PLTE or tRNS chunk changed"); + } +} + +/* By passing a 'standard_display' the progressive callbacks can be used + * directly by the sequential code, the functions suffixed "_imp" are the + * implementations, the functions without the suffix are the callbacks. + * + * The code for the info callback is split into two because this callback calls + * png_read_update_info or png_start_read_image and what gets called depends on + * whether the info needs updating (we want to test both calls in pngvalid.) + */ +static void +standard_info_part1(standard_display *dp, png_structp pp, png_infop pi) +{ + if (png_get_bit_depth(pp, pi) != dp->bit_depth) + png_error(pp, "validate: bit depth changed"); + + if (png_get_color_type(pp, pi) != dp->colour_type) + png_error(pp, "validate: color type changed"); + + if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE) + png_error(pp, "validate: filter type changed"); + + if (png_get_interlace_type(pp, pi) != dp->interlace_type) + png_error(pp, "validate: interlacing changed"); + + if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE) + png_error(pp, "validate: compression type changed"); + + dp->w = png_get_image_width(pp, pi); + + if (dp->w != standard_width(pp, dp->id)) + png_error(pp, "validate: image width changed"); + + dp->h = png_get_image_height(pp, pi); + + if (dp->h != standard_height(pp, dp->id)) + png_error(pp, "validate: image height changed"); + + /* Record (but don't check at present) the input sBIT according to the colour + * type information. + */ + { + png_color_8p sBIT = 0; + + if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT) + { + int sBIT_invalid = 0; + + if (sBIT == 0) + png_error(pp, "validate: unexpected png_get_sBIT result"); + + if (dp->colour_type & PNG_COLOR_MASK_COLOR) + { + if (sBIT->red == 0 || sBIT->red > dp->bit_depth) + sBIT_invalid = 1; + else + dp->red_sBIT = sBIT->red; + + if (sBIT->green == 0 || sBIT->green > dp->bit_depth) + sBIT_invalid = 1; + else + dp->green_sBIT = sBIT->green; + + if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth) + sBIT_invalid = 1; + else + dp->blue_sBIT = sBIT->blue; + } + + else /* !COLOR */ + { + if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth) + sBIT_invalid = 1; + else + dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray; + } + + /* All 8 bits in tRNS for a palette image are significant - see the + * spec. + */ + if (dp->colour_type & PNG_COLOR_MASK_ALPHA) + { + if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth) + sBIT_invalid = 1; + else + dp->alpha_sBIT = sBIT->alpha; + } + + if (sBIT_invalid) + png_error(pp, "validate: sBIT value out of range"); + } + } + + /* Important: this is validating the value *before* any transforms have been + * put in place. It doesn't matter for the standard tests, where there are + * no transforms, but it does for other tests where rowbytes may change after + * png_read_update_info. + */ + if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id)) + png_error(pp, "validate: row size changed"); + + /* Validate the colour type 3 palette (this can be present on other color + * types.) + */ + standard_palette_validate(dp, pp, pi); + + /* In any case always check for a tranparent color (notice that the + * colour type 3 case must not give a successful return on the get_tRNS call + * with these arguments!) + */ + { + png_color_16p trans_color = 0; + + if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS) + { + if (trans_color == 0) + png_error(pp, "validate: unexpected png_get_tRNS (color) result"); + + switch (dp->colour_type) + { + case 0: + dp->transparent.red = dp->transparent.green = dp->transparent.blue = + trans_color->gray; + dp->is_transparent = 1; + break; + + case 2: + dp->transparent.red = trans_color->red; + dp->transparent.green = trans_color->green; + dp->transparent.blue = trans_color->blue; + dp->is_transparent = 1; + break; + + case 3: + /* Not expected because it should result in the array case + * above. + */ + png_error(pp, "validate: unexpected png_get_tRNS result"); + break; + + default: + png_error(pp, "validate: invalid tRNS chunk with alpha image"); + } + } + } + + /* Read the number of passes - expected to match the value used when + * creating the image (interlaced or not). This has the side effect of + * turning on interlace handling (if do_interlace is not set.) + */ + dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type); + if (!dp->do_interlace && dp->npasses != png_set_interlace_handling(pp)) + png_error(pp, "validate: file changed interlace type"); + + /* Caller calls png_read_update_info or png_start_read_image now, then calls + * part2. + */ +} + +/* This must be called *after* the png_read_update_info call to get the correct + * 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed + * image. + */ +static void +standard_info_part2(standard_display *dp, png_const_structp pp, + png_const_infop pi, int nImages) +{ + /* Record cbRow now that it can be found. */ + { + png_byte ct = png_get_color_type(pp, pi); + png_byte bd = png_get_bit_depth(pp, pi); + + if (bd >= 8 && (ct == PNG_COLOR_TYPE_RGB || ct == PNG_COLOR_TYPE_GRAY) && + dp->filler) + ct |= 4; /* handle filler as faked alpha channel */ + + dp->pixel_size = bit_size(pp, ct, bd); + } + dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size; + dp->cbRow = png_get_rowbytes(pp, pi); + + /* Validate the rowbytes here again. */ + if (dp->cbRow != (dp->bit_width+7)/8) + png_error(pp, "bad png_get_rowbytes calculation"); + + /* Then ensure there is enough space for the output image(s). */ + store_ensure_image(dp->ps, pp, nImages, dp->cbRow, dp->h); +} + +static void +standard_info_imp(standard_display *dp, png_structp pp, png_infop pi, + int nImages) +{ + /* Note that the validation routine has the side effect of turning on + * interlace handling in the subsequent code. + */ + standard_info_part1(dp, pp, pi); + + /* And the info callback has to call this (or png_read_update_info - see + * below in the png_modifier code for that variant. + */ + if (dp->use_update_info) + { + /* For debugging the effect of multiple calls: */ + int i = dp->use_update_info; + while (i-- > 0) + png_read_update_info(pp, pi); + } + + else + png_start_read_image(pp); + + /* Validate the height, width and rowbytes plus ensure that sufficient buffer + * exists for decoding the image. + */ + standard_info_part2(dp, pp, pi, nImages); +} + +static void PNGCBAPI +standard_info(png_structp pp, png_infop pi) +{ + standard_display *dp = voidcast(standard_display*, + png_get_progressive_ptr(pp)); + + /* Call with nImages==1 because the progressive reader can only produce one + * image. + */ + standard_info_imp(dp, pp, pi, 1 /*only one image*/); +} + +static void PNGCBAPI +progressive_row(png_structp ppIn, png_bytep new_row, png_uint_32 y, int pass) +{ + png_const_structp pp = ppIn; + PNG_CONST standard_display *dp = voidcast(standard_display*, + png_get_progressive_ptr(pp)); + + /* When handling interlacing some rows will be absent in each pass, the + * callback still gets called, but with a NULL pointer. This is checked + * in the 'else' clause below. We need our own 'cbRow', but we can't call + * png_get_rowbytes because we got no info structure. + */ + if (new_row != NULL) + { + png_bytep row; + + /* In the case where the reader doesn't do the interlace it gives + * us the y in the sub-image: + */ + if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7) + { +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED + /* Use this opportunity to validate the png 'current' APIs: */ + if (y != png_get_current_row_number(pp)) + png_error(pp, "png_get_current_row_number is broken"); + + if (pass != png_get_current_pass_number(pp)) + png_error(pp, "png_get_current_pass_number is broken"); +#endif + + y = PNG_ROW_FROM_PASS_ROW(y, pass); + } + + /* Validate this just in case. */ + if (y >= dp->h) + png_error(pp, "invalid y to progressive row callback"); + + row = store_image_row(dp->ps, pp, 0, y); + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Combine the new row into the old: */ + if (dp->do_interlace) + { + if (dp->interlace_type == PNG_INTERLACE_ADAM7) + deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass); + else + row_copy(row, new_row, dp->pixel_size * dp->w); + } + else + png_progressive_combine_row(pp, row, new_row); +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + } + +#ifdef PNG_READ_INTERLACING_SUPPORTED + else if (dp->interlace_type == PNG_INTERLACE_ADAM7 && + PNG_ROW_IN_INTERLACE_PASS(y, pass) && + PNG_PASS_COLS(dp->w, pass) > 0) + png_error(pp, "missing row in progressive de-interlacing"); +#endif /* PNG_READ_INTERLACING_SUPPORTED */ +} + +static void +sequential_row(standard_display *dp, png_structp pp, png_infop pi, + PNG_CONST int iImage, PNG_CONST int iDisplay) +{ + PNG_CONST int npasses = dp->npasses; + PNG_CONST int do_interlace = dp->do_interlace && + dp->interlace_type == PNG_INTERLACE_ADAM7; + PNG_CONST png_uint_32 height = standard_height(pp, dp->id); + PNG_CONST png_uint_32 width = standard_width(pp, dp->id); + PNG_CONST png_store* ps = dp->ps; + int pass; + + for (pass=0; pass<npasses; ++pass) + { + png_uint_32 y; + png_uint_32 wPass = PNG_PASS_COLS(width, pass); + + for (y=0; y<height; ++y) + { + if (do_interlace) + { + /* wPass may be zero or this row may not be in this pass. + * png_read_row must not be called in either case. + */ + if (wPass > 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass)) + { + /* Read the row into a pair of temporary buffers, then do the + * merge here into the output rows. + */ + png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX]; + + /* The following aids (to some extent) error detection - we can + * see where png_read_row wrote. Use opposite values in row and + * display to make this easier. Don't use 0xff (which is used in + * the image write code to fill unused bits) or 0 (which is a + * likely value to overwrite unused bits with). + */ + memset(row, 0xc5, sizeof row); + memset(display, 0x5c, sizeof display); + + png_read_row(pp, row, display); + + if (iImage >= 0) + deinterlace_row(store_image_row(ps, pp, iImage, y), row, + dp->pixel_size, dp->w, pass); + + if (iDisplay >= 0) + deinterlace_row(store_image_row(ps, pp, iDisplay, y), display, + dp->pixel_size, dp->w, pass); + } + } + else + png_read_row(pp, + iImage >= 0 ? store_image_row(ps, pp, iImage, y) : NULL, + iDisplay >= 0 ? store_image_row(ps, pp, iDisplay, y) : NULL); + } + } + + /* And finish the read operation (only really necessary if the caller wants + * to find additional data in png_info from chunks after the last IDAT.) + */ + png_read_end(pp, pi); +} + +#ifdef PNG_TEXT_SUPPORTED +static void +standard_check_text(png_const_structp pp, png_const_textp tp, + png_const_charp keyword, png_const_charp text) +{ + char msg[1024]; + size_t pos = safecat(msg, sizeof msg, 0, "text: "); + size_t ok; + + pos = safecat(msg, sizeof msg, pos, keyword); + pos = safecat(msg, sizeof msg, pos, ": "); + ok = pos; + + if (tp->compression != TEXT_COMPRESSION) + { + char buf[64]; + + sprintf(buf, "compression [%d->%d], ", TEXT_COMPRESSION, + tp->compression); + pos = safecat(msg, sizeof msg, pos, buf); + } + + if (tp->key == NULL || strcmp(tp->key, keyword) != 0) + { + pos = safecat(msg, sizeof msg, pos, "keyword \""); + if (tp->key != NULL) + { + pos = safecat(msg, sizeof msg, pos, tp->key); + pos = safecat(msg, sizeof msg, pos, "\", "); + } + + else + pos = safecat(msg, sizeof msg, pos, "null, "); + } + + if (tp->text == NULL) + pos = safecat(msg, sizeof msg, pos, "text lost, "); + + else + { + if (tp->text_length != strlen(text)) + { + char buf[64]; + sprintf(buf, "text length changed[%lu->%lu], ", + (unsigned long)strlen(text), (unsigned long)tp->text_length); + pos = safecat(msg, sizeof msg, pos, buf); + } + + if (strcmp(tp->text, text) != 0) + { + pos = safecat(msg, sizeof msg, pos, "text becomes \""); + pos = safecat(msg, sizeof msg, pos, tp->text); + pos = safecat(msg, sizeof msg, pos, "\" (was \""); + pos = safecat(msg, sizeof msg, pos, text); + pos = safecat(msg, sizeof msg, pos, "\"), "); + } + } + + if (tp->itxt_length != 0) + pos = safecat(msg, sizeof msg, pos, "iTXt length set, "); + + if (tp->lang != NULL) + { + pos = safecat(msg, sizeof msg, pos, "iTXt language \""); + pos = safecat(msg, sizeof msg, pos, tp->lang); + pos = safecat(msg, sizeof msg, pos, "\", "); + } + + if (tp->lang_key != NULL) + { + pos = safecat(msg, sizeof msg, pos, "iTXt keyword \""); + pos = safecat(msg, sizeof msg, pos, tp->lang_key); + pos = safecat(msg, sizeof msg, pos, "\", "); + } + + if (pos > ok) + { + msg[pos-2] = '\0'; /* Remove the ", " at the end */ + png_error(pp, msg); + } +} + +static void +standard_text_validate(standard_display *dp, png_const_structp pp, + png_infop pi, int check_end) +{ + png_textp tp = NULL; + png_uint_32 num_text = png_get_text(pp, pi, &tp, NULL); + + if (num_text == 2 && tp != NULL) + { + standard_check_text(pp, tp, "image name", dp->ps->current->name); + + /* This exists because prior to 1.5.18 the progressive reader left the + * png_struct z_stream unreset at the end of the image, so subsequent + * attempts to use it simply returns Z_STREAM_END. + */ + if (check_end) + standard_check_text(pp, tp+1, "end marker", "end"); + } + + else + { + char msg[64]; + + sprintf(msg, "expected two text items, got %lu", + (unsigned long)num_text); + png_error(pp, msg); + } +} +#else +# define standard_text_validate(dp,pp,pi,check_end) ((void)0) +#endif + +static void +standard_row_validate(standard_display *dp, png_const_structp pp, + int iImage, int iDisplay, png_uint_32 y) +{ + int where; + png_byte std[STANDARD_ROWMAX]; + + /* The row must be pre-initialized to the magic number here for the size + * tests to pass: + */ + memset(std, 178, sizeof std); + standard_row(pp, std, dp->id, y); + + /* At the end both the 'row' and 'display' arrays should end up identical. + * In earlier passes 'row' will be partially filled in, with only the pixels + * that have been read so far, but 'display' will have those pixels + * replicated to fill the unread pixels while reading an interlaced image. +#if PNG_LIBPNG_VER < 10506 + * The side effect inside the libpng sequential reader is that the 'row' + * array retains the correct values for unwritten pixels within the row + * bytes, while the 'display' array gets bits off the end of the image (in + * the last byte) trashed. Unfortunately in the progressive reader the + * row bytes are always trashed, so we always do a pixel_cmp here even though + * a memcmp of all cbRow bytes will succeed for the sequential reader. +#endif + */ + if (iImage >= 0 && + (where = pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y), + dp->bit_width)) != 0) + { + char msg[64]; + sprintf(msg, "PNG image row[%lu][%d] changed from %.2x to %.2x", + (unsigned long)y, where-1, std[where-1], + store_image_row(dp->ps, pp, iImage, y)[where-1]); + png_error(pp, msg); + } + +#if PNG_LIBPNG_VER < 10506 + /* In this case use pixel_cmp because we need to compare a partial + * byte at the end of the row if the row is not an exact multiple + * of 8 bits wide. (This is fixed in libpng-1.5.6 and pixel_cmp is + * changed to match!) + */ +#endif + if (iDisplay >= 0 && + (where = pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y), + dp->bit_width)) != 0) + { + char msg[64]; + sprintf(msg, "display row[%lu][%d] changed from %.2x to %.2x", + (unsigned long)y, where-1, std[where-1], + store_image_row(dp->ps, pp, iDisplay, y)[where-1]); + png_error(pp, msg); + } +} + +static void +standard_image_validate(standard_display *dp, png_const_structp pp, int iImage, + int iDisplay) +{ + png_uint_32 y; + + if (iImage >= 0) + store_image_check(dp->ps, pp, iImage); + + if (iDisplay >= 0) + store_image_check(dp->ps, pp, iDisplay); + + for (y=0; y<dp->h; ++y) + standard_row_validate(dp, pp, iImage, iDisplay, y); + + /* This avoids false positives if the validation code is never called! */ + dp->ps->validated = 1; +} + +static void PNGCBAPI +standard_end(png_structp ppIn, png_infop pi) +{ + png_const_structp pp = ppIn; + standard_display *dp = voidcast(standard_display*, + png_get_progressive_ptr(pp)); + + UNUSED(pi) + + /* Validate the image - progressive reading only produces one variant for + * interlaced images. + */ + standard_text_validate(dp, pp, pi, + PNG_LIBPNG_VER >= 10518/*check_end: see comments above*/); + standard_image_validate(dp, pp, 0, -1); +} + +/* A single test run checking the standard image to ensure it is not damaged. */ +static void +standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id, + int do_interlace, int use_update_info) +{ + standard_display d; + context(psIn, fault); + + /* Set up the display (stack frame) variables from the arguments to the + * function and initialize the locals that are filled in later. + */ + standard_display_init(&d, psIn, id, do_interlace, use_update_info); + + /* Everything is protected by a Try/Catch. The functions called also + * typically have local Try/Catch blocks. + */ + Try + { + png_structp pp; + png_infop pi; + + /* Get a png_struct for reading the image. This will throw an error if it + * fails, so we don't need to check the result. + */ + pp = set_store_for_read(d.ps, &pi, d.id, + d.do_interlace ? (d.ps->progressive ? + "pngvalid progressive deinterlacer" : + "pngvalid sequential deinterlacer") : (d.ps->progressive ? + "progressive reader" : "sequential reader")); + + /* Initialize the palette correctly from the png_store_file. */ + standard_palette_init(&d); + + /* Introduce the correct read function. */ + if (d.ps->progressive) + { + png_set_progressive_read_fn(pp, &d, standard_info, progressive_row, + standard_end); + + /* Now feed data into the reader until we reach the end: */ + store_progressive_read(d.ps, pp, pi); + } + else + { + /* Note that this takes the store, not the display. */ + png_set_read_fn(pp, d.ps, store_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* The code tests both versions of the images that the sequential + * reader can produce. + */ + standard_info_imp(&d, pp, pi, 2 /*images*/); + + /* Need the total bytes in the image below; we can't get to this point + * unless the PNG file values have been checked against the expected + * values. + */ + { + sequential_row(&d, pp, pi, 0, 1); + + /* After the last pass loop over the rows again to check that the + * image is correct. + */ + if (!d.speed) + { + standard_text_validate(&d, pp, pi, 1/*check_end*/); + standard_image_validate(&d, pp, 0, 1); + } + else + d.ps->validated = 1; + } + } + + /* Check for validation. */ + if (!d.ps->validated) + png_error(pp, "image read failed silently"); + + /* Successful completion. */ + } + + Catch(fault) + d.ps = fault; /* make sure this hasn't been clobbered. */ + + /* In either case clean up the store. */ + store_read_reset(d.ps); +} + +static int +test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < INTERLACE_LAST; ++interlace_type) + { + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + interlace_type, 0, 0, 0), 0/*do_interlace*/, pm->use_update_info); + + if (fail(pm)) + return 0; + } + } + + return 1; /* keep going */ +} + +static void +perform_standard_test(png_modifier *pm) +{ + /* Test each colour type over the valid range of bit depths (expressed as + * log2(bit_depth) in turn, stop as soon as any error is detected. + */ + if (!test_standard(pm, 0, 0, READ_BDHI)) + return; + + if (!test_standard(pm, 2, 3, READ_BDHI)) + return; + + if (!test_standard(pm, 3, 0, 3)) + return; + + if (!test_standard(pm, 4, 3, READ_BDHI)) + return; + + if (!test_standard(pm, 6, 3, READ_BDHI)) + return; +} + + +/********************************** SIZE TESTS ********************************/ +static int +test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + /* Run the tests on each combination. + * + * NOTE: on my 32 bit x86 each of the following blocks takes + * a total of 3.5 seconds if done across every combo of bit depth + * width and height. This is a waste of time in practice, hence the + * hinc and winc stuff: + */ + static PNG_CONST png_byte hinc[] = {1, 3, 11, 1, 5}; + static PNG_CONST png_byte winc[] = {1, 9, 5, 7, 1}; + for (; bdlo <= bdhi; ++bdlo) + { + png_uint_32 h, w; + + for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo]) + { + /* First test all the 'size' images against the sequential + * reader using libpng to deinterlace (where required.) This + * validates the write side of libpng. There are four possibilities + * to validate. + */ + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + +# ifdef PNG_WRITE_INTERLACING_SUPPORTED + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; +# endif + + /* Now validate the interlaced read side - do_interlace true, + * in the progressive case this does actually make a difference + * to the code used in the non-interlaced case too. + */ + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; + +# ifdef PNG_WRITE_INTERLACING_SUPPORTED + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, + PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/, + pm->use_update_info); + + if (fail(pm)) + return 0; +# endif + } + } + + return 1; /* keep going */ +} + +static void +perform_size_test(png_modifier *pm) +{ + /* Test each colour type over the valid range of bit depths (expressed as + * log2(bit_depth) in turn, stop as soon as any error is detected. + */ + if (!test_size(pm, 0, 0, READ_BDHI)) + return; + + if (!test_size(pm, 2, 3, READ_BDHI)) + return; + + /* For the moment don't do the palette test - it's a waste of time when + * compared to the grayscale test. + */ +#if 0 + if (!test_size(pm, 3, 0, 3)) + return; +#endif + + if (!test_size(pm, 4, 3, READ_BDHI)) + return; + + if (!test_size(pm, 6, 3, READ_BDHI)) + return; +} + + +/******************************* TRANSFORM TESTS ******************************/ +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +/* A set of tests to validate libpng image transforms. The possibilities here + * are legion because the transforms can be combined in a combinatorial + * fashion. To deal with this some measure of restraint is required, otherwise + * the tests would take forever. + */ +typedef struct image_pixel +{ + /* A local (pngvalid) representation of a PNG pixel, in all its + * various forms. + */ + unsigned int red, green, blue, alpha; /* For non-palette images. */ + unsigned int palette_index; /* For a palette image. */ + png_byte colour_type; /* As in the spec. */ + png_byte bit_depth; /* Defines bit size in row */ + png_byte sample_depth; /* Scale of samples */ + unsigned int have_tRNS :1; /* tRNS chunk may need processing */ + unsigned int swap_rgb :1; /* RGB swapped to BGR */ + unsigned int alpha_first :1; /* Alpha at start, not end */ + unsigned int alpha_inverted :1; /* Alpha channel inverted */ + unsigned int mono_inverted :1; /* Gray channel inverted */ + unsigned int swap16 :1; /* Byte swap 16-bit components */ + unsigned int littleendian :1; /* High bits on right */ + unsigned int sig_bits :1; /* Pixel shifted (sig bits only) */ + + /* For checking the code calculates double precision floating point values + * along with an error value, accumulated from the transforms. Because an + * sBIT setting allows larger error bounds (indeed, by the spec, apparently + * up to just less than +/-1 in the scaled value) the *lowest* sBIT for each + * channel is stored. This sBIT value is folded in to the stored error value + * at the end of the application of the transforms to the pixel. + * + * If sig_bits is set above the red, green, blue and alpha values have been + * scaled so they only contain the significant bits of the component values. + */ + double redf, greenf, bluef, alphaf; + double rede, greene, bluee, alphae; + png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT; +} image_pixel; + +/* Shared utility function, see below. */ +static void +image_pixel_setf(image_pixel *this, unsigned int rMax, unsigned int gMax, + unsigned int bMax, unsigned int aMax) +{ + this->redf = this->red / (double)rMax; + this->greenf = this->green / (double)gMax; + this->bluef = this->blue / (double)bMax; + this->alphaf = this->alpha / (double)aMax; + + if (this->red < rMax) + this->rede = this->redf * DBL_EPSILON; + else + this->rede = 0; + if (this->green < gMax) + this->greene = this->greenf * DBL_EPSILON; + else + this->greene = 0; + if (this->blue < bMax) + this->bluee = this->bluef * DBL_EPSILON; + else + this->bluee = 0; + if (this->alpha < aMax) + this->alphae = this->alphaf * DBL_EPSILON; + else + this->alphae = 0; +} + +/* Initialize the structure for the next pixel - call this before doing any + * transforms and call it for each pixel since all the fields may need to be + * reset. + */ +static void +image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type, + png_byte bit_depth, png_uint_32 x, store_palette palette, + PNG_CONST image_pixel *format /*from pngvalid transform of input*/) +{ + PNG_CONST png_byte sample_depth = (png_byte)(colour_type == + PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth); + PNG_CONST unsigned int max = (1U<<sample_depth)-1; + PNG_CONST int swap16 = (format != 0 && format->swap16); + PNG_CONST int littleendian = (format != 0 && format->littleendian); + PNG_CONST int sig_bits = (format != 0 && format->sig_bits); + + /* Initially just set everything to the same number and the alpha to opaque. + * Note that this currently assumes a simple palette where entry x has colour + * rgb(x,x,x)! + */ + this->palette_index = this->red = this->green = this->blue = + sample(row, colour_type, bit_depth, x, 0, swap16, littleendian); + this->alpha = max; + this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT = + sample_depth; + + /* Then override as appropriate: */ + if (colour_type == 3) /* palette */ + { + /* This permits the caller to default to the sample value. */ + if (palette != 0) + { + PNG_CONST unsigned int i = this->palette_index; + + this->red = palette[i].red; + this->green = palette[i].green; + this->blue = palette[i].blue; + this->alpha = palette[i].alpha; + } + } + + else /* not palette */ + { + unsigned int i = 0; + + if ((colour_type & 4) != 0 && format != 0 && format->alpha_first) + { + this->alpha = this->red; + /* This handles the gray case for 'AG' pixels */ + this->palette_index = this->red = this->green = this->blue = + sample(row, colour_type, bit_depth, x, 1, swap16, littleendian); + i = 1; + } + + if (colour_type & 2) + { + /* Green is second for both BGR and RGB: */ + this->green = sample(row, colour_type, bit_depth, x, ++i, swap16, + littleendian); + + if (format != 0 && format->swap_rgb) /* BGR */ + this->red = sample(row, colour_type, bit_depth, x, ++i, swap16, + littleendian); + else + this->blue = sample(row, colour_type, bit_depth, x, ++i, swap16, + littleendian); + } + + else /* grayscale */ if (format != 0 && format->mono_inverted) + this->red = this->green = this->blue = this->red ^ max; + + if ((colour_type & 4) != 0) /* alpha */ + { + if (format == 0 || !format->alpha_first) + this->alpha = sample(row, colour_type, bit_depth, x, ++i, swap16, + littleendian); + + if (format != 0 && format->alpha_inverted) + this->alpha ^= max; + } + } + + /* Calculate the scaled values, these are simply the values divided by + * 'max' and the error is initialized to the double precision epsilon value + * from the header file. + */ + image_pixel_setf(this, + sig_bits ? (1U << format->red_sBIT)-1 : max, + sig_bits ? (1U << format->green_sBIT)-1 : max, + sig_bits ? (1U << format->blue_sBIT)-1 : max, + sig_bits ? (1U << format->alpha_sBIT)-1 : max); + + /* Store the input information for use in the transforms - these will + * modify the information. + */ + this->colour_type = colour_type; + this->bit_depth = bit_depth; + this->sample_depth = sample_depth; + this->have_tRNS = 0; + this->swap_rgb = 0; + this->alpha_first = 0; + this->alpha_inverted = 0; + this->mono_inverted = 0; + this->swap16 = 0; + this->littleendian = 0; + this->sig_bits = 0; +} + +/* Convert a palette image to an rgb image. This necessarily converts the tRNS + * chunk at the same time, because the tRNS will be in palette form. The way + * palette validation works means that the original palette is never updated, + * instead the image_pixel value from the row contains the RGB of the + * corresponding palette entry and *this* is updated. Consequently this routine + * only needs to change the colour type information. + */ +static void +image_pixel_convert_PLTE(image_pixel *this) +{ + if (this->colour_type == PNG_COLOR_TYPE_PALETTE) + { + if (this->have_tRNS) + { + this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + this->have_tRNS = 0; + } + else + this->colour_type = PNG_COLOR_TYPE_RGB; + + /* The bit depth of the row changes at this point too (notice that this is + * the row format, not the sample depth, which is separate.) + */ + this->bit_depth = 8; + } +} + +/* Add an alpha channel; this will import the tRNS information because tRNS is + * not valid in an alpha image. The bit depth will invariably be set to at + * least 8. Palette images will be converted to alpha (using the above API). + */ +static void +image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display) +{ + if (this->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(this); + + if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0) + { + if (this->colour_type == PNG_COLOR_TYPE_GRAY) + { + if (this->bit_depth < 8) + this->bit_depth = 8; + + if (this->have_tRNS) + { + this->have_tRNS = 0; + + /* Check the input, original, channel value here against the + * original tRNS gray chunk valie. + */ + if (this->red == display->transparent.red) + this->alphaf = 0; + else + this->alphaf = 1; + } + else + this->alphaf = 1; + + this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; + } + + else if (this->colour_type == PNG_COLOR_TYPE_RGB) + { + if (this->have_tRNS) + { + this->have_tRNS = 0; + + /* Again, check the exact input values, not the current transformed + * value! + */ + if (this->red == display->transparent.red && + this->green == display->transparent.green && + this->blue == display->transparent.blue) + this->alphaf = 0; + else + this->alphaf = 1; + + this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + } + } + + /* The error in the alpha is zero and the sBIT value comes from the + * original sBIT data (actually it will always be the original bit depth). + */ + this->alphae = 0; + this->alpha_sBIT = display->alpha_sBIT; + } +} + +struct transform_display; +typedef struct image_transform +{ + /* The name of this transform: a string. */ + PNG_CONST char *name; + + /* Each transform can be disabled from the command line: */ + int enable; + + /* The global list of transforms; read only. */ + struct image_transform *PNG_CONST list; + + /* The global count of the number of times this transform has been set on an + * image. + */ + unsigned int global_use; + + /* The local count of the number of times this transform has been set. */ + unsigned int local_use; + + /* The next transform in the list, each transform must call its own next + * transform after it has processed the pixel successfully. + */ + PNG_CONST struct image_transform *next; + + /* A single transform for the image, expressed as a series of function + * callbacks and some space for values. + * + * First a callback to add any required modifications to the png_modifier; + * this gets called just before the modifier is set up for read. + */ + void (*ini)(PNG_CONST struct image_transform *this, + struct transform_display *that); + + /* And a callback to set the transform on the current png_read_struct: + */ + void (*set)(PNG_CONST struct image_transform *this, + struct transform_display *that, png_structp pp, png_infop pi); + + /* Then a transform that takes an input pixel in one PNG format or another + * and modifies it by a pngvalid implementation of the transform (thus + * duplicating the libpng intent without, we hope, duplicating the bugs + * in the libpng implementation!) The png_structp is solely to allow error + * reporting via png_error and png_warning. + */ + void (*mod)(PNG_CONST struct image_transform *this, image_pixel *that, + png_const_structp pp, PNG_CONST struct transform_display *display); + + /* Add this transform to the list and return true if the transform is + * meaningful for this colour type and bit depth - if false then the + * transform should have no effect on the image so there's not a lot of + * point running it. + */ + int (*add)(struct image_transform *this, + PNG_CONST struct image_transform **that, png_byte colour_type, + png_byte bit_depth); +} image_transform; + +typedef struct transform_display +{ + standard_display this; + + /* Parameters */ + png_modifier* pm; + PNG_CONST image_transform* transform_list; + + /* Local variables */ + png_byte output_colour_type; + png_byte output_bit_depth; + png_byte unpacked; + + /* Modifications (not necessarily used.) */ + gama_modification gama_mod; + chrm_modification chrm_mod; + srgb_modification srgb_mod; +} transform_display; + +/* Set sRGB, cHRM and gAMA transforms as required by the current encoding. */ +static void +transform_set_encoding(transform_display *this) +{ + /* Set up the png_modifier '_current' fields then use these to determine how + * to add appropriate chunks. + */ + png_modifier *pm = this->pm; + + modifier_set_encoding(pm); + + if (modifier_color_encoding_is_set(pm)) + { + if (modifier_color_encoding_is_sRGB(pm)) + srgb_modification_init(&this->srgb_mod, pm, PNG_sRGB_INTENT_ABSOLUTE); + + else + { + /* Set gAMA and cHRM separately. */ + gama_modification_init(&this->gama_mod, pm, pm->current_gamma); + + if (pm->current_encoding != 0) + chrm_modification_init(&this->chrm_mod, pm, pm->current_encoding); + } + } +} + +/* Three functions to end the list: */ +static void +image_transform_ini_end(PNG_CONST image_transform *this, + transform_display *that) +{ + UNUSED(this) + UNUSED(that) +} + +static void +image_transform_set_end(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + UNUSED(this) + UNUSED(that) + UNUSED(pp) + UNUSED(pi) +} + +/* At the end of the list recalculate the output image pixel value from the + * double precision values set up by the preceding 'mod' calls: + */ +static unsigned int +sample_scale(double sample_value, unsigned int scale) +{ + sample_value = floor(sample_value * scale + .5); + + /* Return NaN as 0: */ + if (!(sample_value > 0)) + sample_value = 0; + else if (sample_value > scale) + sample_value = scale; + + return (unsigned int)sample_value; +} + +static void +image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that, + png_const_structp pp, PNG_CONST transform_display *display) +{ + PNG_CONST unsigned int scale = (1U<<that->sample_depth)-1; + PNG_CONST int sig_bits = that->sig_bits; + + UNUSED(this) + UNUSED(pp) + UNUSED(display) + + /* At the end recalculate the digitized red green and blue values according + * to the current sample_depth of the pixel. + * + * The sample value is simply scaled to the maximum, checking for over + * and underflow (which can both happen for some image transforms, + * including simple size scaling, though libpng doesn't do that at present. + */ + that->red = sample_scale(that->redf, scale); + + /* This is a bit bogus; really the above calculation should use the red_sBIT + * value, not sample_depth, but because libpng does png_set_shift by just + * shifting the bits we get errors if we don't do it the same way. + */ + if (sig_bits && that->red_sBIT < that->sample_depth) + that->red >>= that->sample_depth - that->red_sBIT; + + /* The error value is increased, at the end, according to the lowest sBIT + * value seen. Common sense tells us that the intermediate integer + * representations are no more accurate than +/- 0.5 in the integral values, + * the sBIT allows the implementation to be worse than this. In addition the + * PNG specification actually permits any error within the range (-1..+1), + * but that is ignored here. Instead the final digitized value is compared, + * below to the digitized value of the error limits - this has the net effect + * of allowing (almost) +/-1 in the output value. It's difficult to see how + * any algorithm that digitizes intermediate results can be more accurate. + */ + that->rede += 1./(2*((1U<<that->red_sBIT)-1)); + + if (that->colour_type & PNG_COLOR_MASK_COLOR) + { + that->green = sample_scale(that->greenf, scale); + if (sig_bits && that->green_sBIT < that->sample_depth) + that->green >>= that->sample_depth - that->green_sBIT; + + that->blue = sample_scale(that->bluef, scale); + if (sig_bits && that->blue_sBIT < that->sample_depth) + that->blue >>= that->sample_depth - that->blue_sBIT; + + that->greene += 1./(2*((1U<<that->green_sBIT)-1)); + that->bluee += 1./(2*((1U<<that->blue_sBIT)-1)); + } + else + { + that->blue = that->green = that->red; + that->bluef = that->greenf = that->redf; + that->bluee = that->greene = that->rede; + } + + if ((that->colour_type & PNG_COLOR_MASK_ALPHA) || + that->colour_type == PNG_COLOR_TYPE_PALETTE) + { + that->alpha = sample_scale(that->alphaf, scale); + that->alphae += 1./(2*((1U<<that->alpha_sBIT)-1)); + } + else + { + that->alpha = scale; /* opaque */ + that->alphaf = 1; /* Override this. */ + that->alphae = 0; /* It's exact ;-) */ + } + + if (sig_bits && that->alpha_sBIT < that->sample_depth) + that->alpha >>= that->sample_depth - that->alpha_sBIT; +} + +/* Static 'end' structure: */ +static image_transform image_transform_end = +{ + "(end)", /* name */ + 1, /* enable */ + 0, /* list */ + 0, /* global_use */ + 0, /* local_use */ + 0, /* next */ + image_transform_ini_end, + image_transform_set_end, + image_transform_mod_end, + 0 /* never called, I want it to crash if it is! */ +}; + +/* Reader callbacks and implementations, where they differ from the standard + * ones. + */ +static void +transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id, + PNG_CONST image_transform *transform_list) +{ + memset(dp, 0, sizeof *dp); + + /* Standard fields */ + standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, + pm->use_update_info); + + /* Parameter fields */ + dp->pm = pm; + dp->transform_list = transform_list; + + /* Local variable fields */ + dp->output_colour_type = 255; /* invalid */ + dp->output_bit_depth = 255; /* invalid */ + dp->unpacked = 0; /* not unpacked */ +} + +static void +transform_info_imp(transform_display *dp, png_structp pp, png_infop pi) +{ + /* Reuse the standard stuff as appropriate. */ + standard_info_part1(&dp->this, pp, pi); + + /* Now set the list of transforms. */ + dp->transform_list->set(dp->transform_list, dp, pp, pi); + + /* Update the info structure for these transforms: */ + { + int i = dp->this.use_update_info; + /* Always do one call, even if use_update_info is 0. */ + do + png_read_update_info(pp, pi); + while (--i > 0); + } + + /* And get the output information into the standard_display */ + standard_info_part2(&dp->this, pp, pi, 1/*images*/); + + /* Plus the extra stuff we need for the transform tests: */ + dp->output_colour_type = png_get_color_type(pp, pi); + dp->output_bit_depth = png_get_bit_depth(pp, pi); + + /* If png_set_filler is in action then fake the output color type to include + * an alpha channel where appropriate. + */ + if (dp->output_bit_depth >= 8 && (dp->output_colour_type == PNG_COLOR_TYPE_RGB || + dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler) + dp->output_colour_type |= 4; + + /* Validate the combination of colour type and bit depth that we are getting + * out of libpng; the semantics of something not in the PNG spec are, at + * best, unclear. + */ + switch (dp->output_colour_type) + { + case PNG_COLOR_TYPE_PALETTE: + if (dp->output_bit_depth > 8) goto error; + /*FALL THROUGH*/ + case PNG_COLOR_TYPE_GRAY: + if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 || + dp->output_bit_depth == 4) + break; + /*FALL THROUGH*/ + default: + if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16) + break; + /*FALL THROUGH*/ + error: + { + char message[128]; + size_t pos; + + pos = safecat(message, sizeof message, 0, + "invalid final bit depth: colour type("); + pos = safecatn(message, sizeof message, pos, dp->output_colour_type); + pos = safecat(message, sizeof message, pos, ") with bit depth: "); + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + + png_error(pp, message); + } + } + + /* Use a test pixel to check that the output agrees with what we expect - + * this avoids running the whole test if the output is unexpected. This also + * checks for internal errors. + */ + { + image_pixel test_pixel; + + memset(&test_pixel, 0, sizeof test_pixel); + test_pixel.colour_type = dp->this.colour_type; /* input */ + test_pixel.bit_depth = dp->this.bit_depth; + if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) + test_pixel.sample_depth = 8; + else + test_pixel.sample_depth = test_pixel.bit_depth; + /* Don't need sBIT here, but it must be set to non-zero to avoid + * arithmetic overflows. + */ + test_pixel.have_tRNS = dp->this.is_transparent != 0; + test_pixel.red_sBIT = test_pixel.green_sBIT = test_pixel.blue_sBIT = + test_pixel.alpha_sBIT = test_pixel.sample_depth; + + dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp); + + if (test_pixel.colour_type != dp->output_colour_type) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, "colour type "); + + pos = safecatn(message, sizeof message, pos, dp->output_colour_type); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.colour_type); + + png_error(pp, message); + } + + if (test_pixel.bit_depth != dp->output_bit_depth) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, "bit depth "); + + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); + + png_error(pp, message); + } + + /* If both bit depth and colour type are correct check the sample depth. + */ + if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE && + test_pixel.sample_depth != 8) /* oops - internal error! */ + png_error(pp, "pngvalid: internal: palette sample depth not 8"); + else if (dp->unpacked && test_pixel.bit_depth != 8) + png_error(pp, "pngvalid: internal: bad unpacked pixel depth"); + else if (!dp->unpacked && test_pixel.colour_type != PNG_COLOR_TYPE_PALETTE + && test_pixel.bit_depth != test_pixel.sample_depth) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, + "internal: sample depth "); + + /* Because unless something has set 'unpacked' or the image is palette + * mapped we expect the transform to keep sample depth and bit depth + * the same. + */ + pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); + + png_error(pp, message); + } + else if (test_pixel.bit_depth != dp->output_bit_depth) + { + /* This could be a libpng error too; libpng has not produced what we + * expect for the output bit depth. + */ + char message[128]; + size_t pos = safecat(message, sizeof message, 0, + "internal: bit depth "); + + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); + + png_error(pp, message); + } + } +} + +static void PNGCBAPI +transform_info(png_structp pp, png_infop pi) +{ + transform_info_imp(voidcast(transform_display*, png_get_progressive_ptr(pp)), + pp, pi); +} + +static void +transform_range_check(png_const_structp pp, unsigned int r, unsigned int g, + unsigned int b, unsigned int a, unsigned int in_digitized, double in, + unsigned int out, png_byte sample_depth, double err, double limit, + PNG_CONST char *name, double digitization_error) +{ + /* Compare the scaled, digitzed, values of our local calculation (in+-err) + * with the digitized values libpng produced; 'sample_depth' is the actual + * digitization depth of the libpng output colors (the bit depth except for + * palette images where it is always 8.) The check on 'err' is to detect + * internal errors in pngvalid itself. + */ + unsigned int max = (1U<<sample_depth)-1; + double in_min = ceil((in-err)*max - digitization_error); + double in_max = floor((in+err)*max + digitization_error); + if (err > limit || !(out >= in_min && out <= in_max)) + { + char message[256]; + size_t pos; + + pos = safecat(message, sizeof message, 0, name); + pos = safecat(message, sizeof message, pos, " output value error: rgba("); + pos = safecatn(message, sizeof message, pos, r); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, g); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, b); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, a); + pos = safecat(message, sizeof message, pos, "): "); + pos = safecatn(message, sizeof message, pos, out); + pos = safecat(message, sizeof message, pos, " expected: "); + pos = safecatn(message, sizeof message, pos, in_digitized); + pos = safecat(message, sizeof message, pos, " ("); + pos = safecatd(message, sizeof message, pos, (in-err)*max, 3); + pos = safecat(message, sizeof message, pos, ".."); + pos = safecatd(message, sizeof message, pos, (in+err)*max, 3); + pos = safecat(message, sizeof message, pos, ")"); + + png_error(pp, message); + } +} + +static void +transform_image_validate(transform_display *dp, png_const_structp pp, + png_infop pi) +{ + /* Constants for the loop below: */ + PNG_CONST png_store* PNG_CONST ps = dp->this.ps; + PNG_CONST png_byte in_ct = dp->this.colour_type; + PNG_CONST png_byte in_bd = dp->this.bit_depth; + PNG_CONST png_uint_32 w = dp->this.w; + PNG_CONST png_uint_32 h = dp->this.h; + PNG_CONST png_byte out_ct = dp->output_colour_type; + PNG_CONST png_byte out_bd = dp->output_bit_depth; + PNG_CONST png_byte sample_depth = (png_byte)(out_ct == + PNG_COLOR_TYPE_PALETTE ? 8 : out_bd); + PNG_CONST png_byte red_sBIT = dp->this.red_sBIT; + PNG_CONST png_byte green_sBIT = dp->this.green_sBIT; + PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT; + PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT; + PNG_CONST int have_tRNS = dp->this.is_transparent; + double digitization_error; + + store_palette out_palette; + png_uint_32 y; + + UNUSED(pi) + + /* Check for row overwrite errors */ + store_image_check(dp->this.ps, pp, 0); + + /* Read the palette corresponding to the output if the output colour type + * indicates a palette, othewise set out_palette to garbage. + */ + if (out_ct == PNG_COLOR_TYPE_PALETTE) + { + /* Validate that the palette count itself has not changed - this is not + * expected. + */ + int npalette = (-1); + + (void)read_palette(out_palette, &npalette, pp, pi); + if (npalette != dp->this.npalette) + png_error(pp, "unexpected change in palette size"); + + digitization_error = .5; + } + else + { + png_byte in_sample_depth; + + memset(out_palette, 0x5e, sizeof out_palette); + + /* use-input-precision means assume that if the input has 8 bit (or less) + * samples and the output has 16 bit samples the calculations will be done + * with 8 bit precision, not 16. + */ + if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16) + in_sample_depth = 8; + else + in_sample_depth = in_bd; + + if (sample_depth != 16 || in_sample_depth > 8 || + !dp->pm->calculations_use_input_precision) + digitization_error = .5; + + /* Else calculations are at 8 bit precision, and the output actually + * consists of scaled 8-bit values, so scale .5 in 8 bits to the 16 bits: + */ + else + digitization_error = .5 * 257; + } + + for (y=0; y<h; ++y) + { + png_const_bytep PNG_CONST pRow = store_image_row(ps, pp, 0, y); + png_uint_32 x; + + /* The original, standard, row pre-transforms. */ + png_byte std[STANDARD_ROWMAX]; + + transform_row(pp, std, in_ct, in_bd, y); + + /* Go through each original pixel transforming it and comparing with what + * libpng did to the same pixel. + */ + for (x=0; x<w; ++x) + { + image_pixel in_pixel, out_pixel; + unsigned int r, g, b, a; + + /* Find out what we think the pixel should be: */ + image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette, + NULL); + + in_pixel.red_sBIT = red_sBIT; + in_pixel.green_sBIT = green_sBIT; + in_pixel.blue_sBIT = blue_sBIT; + in_pixel.alpha_sBIT = alpha_sBIT; + in_pixel.have_tRNS = have_tRNS != 0; + + /* For error detection, below. */ + r = in_pixel.red; + g = in_pixel.green; + b = in_pixel.blue; + a = in_pixel.alpha; + + /* This applies the transforms to the input date, including output + * format operations which must be used when reading the output + * pixel that libpng produces. + */ + dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp); + + /* Read the output pixel and compare it to what we got, we don't + * use the error field here, so no need to update sBIT. in_pixel + * says whether we expect libpng to change the output format. + */ + image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette, + &in_pixel); + + /* We don't expect changes to the index here even if the bit depth is + * changed. + */ + if (in_ct == PNG_COLOR_TYPE_PALETTE && + out_ct == PNG_COLOR_TYPE_PALETTE) + { + if (in_pixel.palette_index != out_pixel.palette_index) + png_error(pp, "unexpected transformed palette index"); + } + + /* Check the colours for palette images too - in fact the palette could + * be separately verified itself in most cases. + */ + if (in_pixel.red != out_pixel.red) + transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf, + out_pixel.red, sample_depth, in_pixel.rede, + dp->pm->limit + 1./(2*((1U<<in_pixel.red_sBIT)-1)), "red/gray", + digitization_error); + + if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && + in_pixel.green != out_pixel.green) + transform_range_check(pp, r, g, b, a, in_pixel.green, + in_pixel.greenf, out_pixel.green, sample_depth, in_pixel.greene, + dp->pm->limit + 1./(2*((1U<<in_pixel.green_sBIT)-1)), "green", + digitization_error); + + if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && + in_pixel.blue != out_pixel.blue) + transform_range_check(pp, r, g, b, a, in_pixel.blue, in_pixel.bluef, + out_pixel.blue, sample_depth, in_pixel.bluee, + dp->pm->limit + 1./(2*((1U<<in_pixel.blue_sBIT)-1)), "blue", + digitization_error); + + if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0 && + in_pixel.alpha != out_pixel.alpha) + transform_range_check(pp, r, g, b, a, in_pixel.alpha, + in_pixel.alphaf, out_pixel.alpha, sample_depth, in_pixel.alphae, + dp->pm->limit + 1./(2*((1U<<in_pixel.alpha_sBIT)-1)), "alpha", + digitization_error); + } /* pixel (x) loop */ + } /* row (y) loop */ + + /* Record that something was actually checked to avoid a false positive. */ + dp->this.ps->validated = 1; +} + +static void PNGCBAPI +transform_end(png_structp ppIn, png_infop pi) +{ + png_const_structp pp = ppIn; + transform_display *dp = voidcast(transform_display*, + png_get_progressive_ptr(pp)); + + if (!dp->this.speed) + transform_image_validate(dp, pp, pi); + else + dp->this.ps->validated = 1; +} + +/* A single test run. */ +static void +transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn, + PNG_CONST image_transform* transform_listIn, PNG_CONST char * volatile name) +{ + transform_display d; + context(&pmIn->this, fault); + + transform_display_init(&d, pmIn, idIn, transform_listIn); + + Try + { + size_t pos = 0; + png_structp pp; + png_infop pi; + char full_name[256]; + + /* Make sure the encoding fields are correct and enter the required + * modifications. + */ + transform_set_encoding(&d); + + /* Add any modifications required by the transform list. */ + d.transform_list->ini(d.transform_list, &d); + + /* Add the color space information, if any, to the name. */ + pos = safecat(full_name, sizeof full_name, pos, name); + pos = safecat_current_encoding(full_name, sizeof full_name, pos, d.pm); + + /* Get a png_struct for reading the image. */ + pp = set_modifier_for_read(d.pm, &pi, d.this.id, full_name); + standard_palette_init(&d.this); + +# if 0 + /* Logging (debugging only) */ + { + char buffer[256]; + + (void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0, + "running test"); + + fprintf(stderr, "%s\n", buffer); + } +# endif + + /* Introduce the correct read function. */ + if (d.pm->this.progressive) + { + /* Share the row function with the standard implementation. */ + png_set_progressive_read_fn(pp, &d, transform_info, progressive_row, + transform_end); + + /* Now feed data into the reader until we reach the end: */ + modifier_progressive_read(d.pm, pp, pi); + } + else + { + /* modifier_read expects a png_modifier* */ + png_set_read_fn(pp, d.pm, modifier_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* Process the 'info' requirements. Only one image is generated */ + transform_info_imp(&d, pp, pi); + + sequential_row(&d.this, pp, pi, -1, 0); + + if (!d.this.speed) + transform_image_validate(&d, pp, pi); + else + d.this.ps->validated = 1; + } + + modifier_reset(d.pm); + } + + Catch(fault) + { + modifier_reset(voidcast(png_modifier*,(void*)fault)); + } +} + +/* The transforms: */ +#define ITSTRUCT(name) image_transform_##name +#define ITDATA(name) image_transform_data_##name +#define image_transform_ini image_transform_default_ini +#define IT(name)\ +static image_transform ITSTRUCT(name) =\ +{\ + #name,\ + 1, /*enable*/\ + &PT, /*list*/\ + 0, /*global_use*/\ + 0, /*local_use*/\ + 0, /*next*/\ + image_transform_ini,\ + image_transform_png_set_##name##_set,\ + image_transform_png_set_##name##_mod,\ + image_transform_png_set_##name##_add\ +} +#define PT ITSTRUCT(end) /* stores the previous transform */ + +/* To save code: */ +static void +image_transform_default_ini(PNG_CONST image_transform *this, + transform_display *that) +{ + this->next->ini(this->next, that); +} + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +static int +image_transform_default_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return 1; +} +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_palette_to_rgb */ +static void +image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_palette_to_rgb(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_palette_to_rgb_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return colour_type == PNG_COLOR_TYPE_PALETTE; +} + +IT(palette_to_rgb); +#undef PT +#define PT ITSTRUCT(palette_to_rgb) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_tRNS_to_alpha */ +static void +image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_tRNS_to_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + /* LIBPNG BUG: this always forces palette images to RGB. */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + /* This effectively does an 'expand' only if there is some transparency to + * convert to an alpha channel. + */ + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */ + else + { + if (that->bit_depth < 8) + that->bit_depth =8; + if (that->sample_depth < 8) + that->sample_depth = 8; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_tRNS_to_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* We don't know yet whether there will be a tRNS chunk, but we know that + * this transformation should do nothing if there already is an alpha + * channel. + */ + return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; +} + +IT(tRNS_to_alpha); +#undef PT +#define PT ITSTRUCT(tRNS_to_alpha) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* png_set_gray_to_rgb */ +static void +image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_gray_to_rgb(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_gray_to_rgb_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + /* NOTE: we can actually pend the tRNS processing at this point because we + * can correctly recognize the original pixel value even though we have + * mapped the one gray channel to the three RGB ones, but in fact libpng + * doesn't do this, so we don't either. + */ + if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + /* Simply expand the bit depth and alter the colour type as required. */ + if (that->colour_type == PNG_COLOR_TYPE_GRAY) + { + /* RGB images have a bit depth at least equal to '8' */ + if (that->bit_depth < 8) + that->sample_depth = that->bit_depth = 8; + + /* And just changing the colour type works here because the green and blue + * channels are being maintained in lock-step with the red/gray: + */ + that->colour_type = PNG_COLOR_TYPE_RGB; + } + + else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_gray_to_rgb_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_COLOR) == 0; +} + +IT(gray_to_rgb); +#undef PT +#define PT ITSTRUCT(gray_to_rgb) +#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_expand */ +static void +image_transform_png_set_expand_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_expand(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + /* The general expand case depends on what the colour type is: */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + else if (that->bit_depth < 8) /* grayscale */ + that->sample_depth = that->bit_depth = 8; + + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_expand_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit + * depth is at least 8 already. + */ + return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; +} + +IT(expand); +#undef PT +#define PT ITSTRUCT(expand) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* png_set_expand_gray_1_2_4_to_8 + * LIBPNG BUG: this just does an 'expand' + */ +static void +image_transform_png_set_expand_gray_1_2_4_to_8_set( + PNG_CONST image_transform *this, transform_display *that, png_structp pp, + png_infop pi) +{ + png_set_expand_gray_1_2_4_to_8(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_gray_1_2_4_to_8_mod( + PNG_CONST image_transform *this, image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + image_transform_png_set_expand_mod(this, that, pp, display); +} + +static int +image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + return image_transform_png_set_expand_add(this, that, colour_type, + bit_depth); +} + +IT(expand_gray_1_2_4_to_8); +#undef PT +#define PT ITSTRUCT(expand_gray_1_2_4_to_8) +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_16_SUPPORTED +/* png_set_expand_16 */ +static void +image_transform_png_set_expand_16_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_expand_16(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_16_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + /* Expect expand_16 to expand everything to 16 bits as a result of also + * causing 'expand' to happen. + */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + if (that->bit_depth < 16) + that->sample_depth = that->bit_depth = 16; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_expand_16_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + /* expand_16 does something unless the bit depth is already 16. */ + return bit_depth < 16; +} + +IT(expand_16); +#undef PT +#define PT ITSTRUCT(expand_16) +#endif /* PNG_READ_EXPAND_16_SUPPORTED */ + +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED /* API added in 1.5.4 */ +/* png_set_scale_16 */ +static void +image_transform_png_set_scale_16_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_scale_16(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_scale_16_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->bit_depth == 16) + { + that->sample_depth = that->bit_depth = 8; + if (that->red_sBIT > 8) that->red_sBIT = 8; + if (that->green_sBIT > 8) that->green_sBIT = 8; + if (that->blue_sBIT > 8) that->blue_sBIT = 8; + if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_scale_16_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + return bit_depth > 8; +} + +IT(scale_16); +#undef PT +#define PT ITSTRUCT(scale_16) +#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */ + +#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */ +/* png_set_strip_16 */ +static void +image_transform_png_set_strip_16_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_strip_16(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->bit_depth == 16) + { + that->sample_depth = that->bit_depth = 8; + if (that->red_sBIT > 8) that->red_sBIT = 8; + if (that->green_sBIT > 8) that->green_sBIT = 8; + if (that->blue_sBIT > 8) that->blue_sBIT = 8; + if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; + + /* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this + * configuration option is set. From 1.5.4 the flag is never set and the + * 'scale' API (above) must be used. + */ +# ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED +# if PNG_LIBPNG_VER >= 10504 +# error PNG_READ_ACCURATE_SCALE should not be set +# endif + + /* The strip 16 algorithm drops the low 8 bits rather than calculating + * 1/257, so we need to adjust the permitted errors appropriately: + * Notice that this is only relevant prior to the addition of the + * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!) + */ + { + PNG_CONST double d = (255-128.5)/65535; + that->rede += d; + that->greene += d; + that->bluee += d; + that->alphae += d; + } +# endif + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_strip_16_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + return bit_depth > 8; +} + +IT(strip_16); +#undef PT +#define PT ITSTRUCT(strip_16) +#endif /* PNG_READ_16_TO_8_SUPPORTED */ + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +/* png_set_strip_alpha */ +static void +image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_strip_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY; + else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB; + + that->have_tRNS = 0; + that->alphaf = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_strip_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_ALPHA) != 0; +} + +IT(strip_alpha); +#undef PT +#define PT ITSTRUCT(strip_alpha) +#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */ + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green) + * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red, + * png_fixed_point green) + * png_get_rgb_to_gray_status + * + * The 'default' test here uses values known to be used inside libpng: + * + * red: 6968 + * green: 23434 + * blue: 2366 + * + * These values are being retained for compatibility, along with the somewhat + * broken truncation calculation in the fast-and-inaccurate code path. Older + * versions of libpng will fail the accuracy tests below because they use the + * truncation algorithm everywhere. + */ +#define data ITDATA(rgb_to_gray) +static struct +{ + double gamma; /* File gamma to use in processing */ + + /* The following are the parameters for png_set_rgb_to_gray: */ +# ifdef PNG_FLOATING_POINT_SUPPORTED + double red_to_set; + double green_to_set; +# else + png_fixed_point red_to_set; + png_fixed_point green_to_set; +# endif + + /* The actual coefficients: */ + double red_coefficient; + double green_coefficient; + double blue_coefficient; + + /* Set if the coeefficients have been overridden. */ + int coefficients_overridden; +} data; + +#undef image_transform_ini +#define image_transform_ini image_transform_png_set_rgb_to_gray_ini +static void +image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this, + transform_display *that) +{ + png_modifier *pm = that->pm; + PNG_CONST color_encoding *e = pm->current_encoding; + + UNUSED(this) + + /* Since we check the encoding this flag must be set: */ + pm->test_uses_encoding = 1; + + /* If 'e' is not NULL chromaticity information is present and either a cHRM + * or an sRGB chunk will be inserted. + */ + if (e != 0) + { + /* Coefficients come from the encoding, but may need to be normalized to a + * white point Y of 1.0 + */ + PNG_CONST double whiteY = e->red.Y + e->green.Y + e->blue.Y; + + data.red_coefficient = e->red.Y; + data.green_coefficient = e->green.Y; + data.blue_coefficient = e->blue.Y; + + if (whiteY != 1) + { + data.red_coefficient /= whiteY; + data.green_coefficient /= whiteY; + data.blue_coefficient /= whiteY; + } + } + + else + { + /* The default (built in) coeffcients, as above: */ + data.red_coefficient = 6968 / 32768.; + data.green_coefficient = 23434 / 32768.; + data.blue_coefficient = 2366 / 32768.; + } + + data.gamma = pm->current_gamma; + + /* If not set then the calculations assume linear encoding (implicitly): */ + if (data.gamma == 0) + data.gamma = 1; + + /* The arguments to png_set_rgb_to_gray can override the coefficients implied + * by the color space encoding. If doing exhaustive checks do the override + * in each case, otherwise do it randomly. + */ + if (pm->test_exhaustive) + { + /* First time in coefficients_overridden is 0, the following sets it to 1, + * so repeat if it is set. If a test fails this may mean we subsequently + * skip a non-override test, ignore that. + */ + data.coefficients_overridden = !data.coefficients_overridden; + pm->repeat = data.coefficients_overridden != 0; + } + + else + data.coefficients_overridden = random_choice(); + + if (data.coefficients_overridden) + { + /* These values override the color encoding defaults, simply use random + * numbers. + */ + png_uint_32 ru; + double total; + + RANDOMIZE(ru); + data.green_coefficient = total = (ru & 0xffff) / 65535.; + ru >>= 16; + data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.; + total += data.red_coefficient; + data.blue_coefficient = 1 - total; + +# ifdef PNG_FLOATING_POINT_SUPPORTED + data.red_to_set = data.red_coefficient; + data.green_to_set = data.green_coefficient; +# else + data.red_to_set = fix(data.red_coefficient); + data.green_to_set = fix(data.green_coefficient); +# endif + + /* The following just changes the error messages: */ + pm->encoding_ignored = 1; + } + + else + { + data.red_to_set = -1; + data.green_to_set = -1; + } + + /* Adjust the error limit in the png_modifier because of the larger errors + * produced in the digitization during the gamma handling. + */ + if (data.gamma != 1) /* Use gamma tables */ + { + if (that->this.bit_depth == 16 || pm->assume_16_bit_calculations) + { + /* The computations have the form: + * + * r * rc + g * gc + b * bc + * + * Each component of which is +/-1/65535 from the gamma_to_1 table + * lookup, resulting in a base error of +/-6. The gamma_from_1 + * conversion adds another +/-2 in the 16-bit case and + * +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case. + */ + that->pm->limit += pow( +# if PNG_MAX_GAMMA_8 < 14 + (that->this.bit_depth == 16 ? 8. : + 6. + (1<<(15-PNG_MAX_GAMMA_8))) +# else + 8. +# endif + /65535, data.gamma); + } + + else + { + /* Rounding to 8 bits in the linear space causes massive errors which + * will trigger the error check in transform_range_check. Fix that + * here by taking the gamma encoding into account. + * + * When DIGITIZE is set because a pre-1.7 version of libpng is being + * tested allow a bigger slack. + * + * NOTE: this magic number was determined by experiment to be 1.25. + * There's no great merit to the value below, however it only affects + * the limit used for checking for internal calculation errors, not + * the actual limit imposed by pngvalid on the output errors. + */ + that->pm->limit += pow( +# if DIGITIZE + 1.25 +# else + 1.0 +# endif + /255, data.gamma); + } + } + + else + { + /* With no gamma correction a large error comes from the truncation of the + * calculation in the 8 bit case, allow for that here. + */ + if (that->this.bit_depth != 16 && !pm->assume_16_bit_calculations) + that->pm->limit += 4E-3; + } +} + +static void +image_transform_png_set_rgb_to_gray_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + PNG_CONST int error_action = 1; /* no error, no defines in png.h */ + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_rgb_to_gray(pp, error_action, data.red_to_set, data.green_to_set); +# else + png_set_rgb_to_gray_fixed(pp, error_action, data.red_to_set, + data.green_to_set); +# endif + +# ifdef PNG_READ_cHRM_SUPPORTED + if (that->pm->current_encoding != 0) + { + /* We have an encoding so a cHRM chunk may have been set; if so then + * check that the libpng APIs give the correct (X,Y,Z) values within + * some margin of error for the round trip through the chromaticity + * form. + */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +# define API_function png_get_cHRM_XYZ +# define API_form "FP" +# define API_type double +# define API_cvt(x) (x) +# else +# define API_function png_get_cHRM_XYZ_fixed +# define API_form "fixed" +# define API_type png_fixed_point +# define API_cvt(x) ((double)(x)/PNG_FP_1) +# endif + + API_type rX, gX, bX; + API_type rY, gY, bY; + API_type rZ, gZ, bZ; + + if ((API_function(pp, pi, &rX, &rY, &rZ, &gX, &gY, &gZ, &bX, &bY, &bZ) + & PNG_INFO_cHRM) != 0) + { + double maxe; + PNG_CONST char *el; + color_encoding e, o; + + /* Expect libpng to return a normalized result, but the original + * color space encoding may not be normalized. + */ + modifier_current_encoding(that->pm, &o); + normalize_color_encoding(&o); + + /* Sanity check the pngvalid code - the coefficients should match + * the normalized Y values of the encoding unless they were + * overridden. + */ + if (data.red_to_set == -1 && data.green_to_set == -1 && + (fabs(o.red.Y - data.red_coefficient) > DBL_EPSILON || + fabs(o.green.Y - data.green_coefficient) > DBL_EPSILON || + fabs(o.blue.Y - data.blue_coefficient) > DBL_EPSILON)) + png_error(pp, "internal pngvalid cHRM coefficient error"); + + /* Generate a colour space encoding. */ + e.gamma = o.gamma; /* not used */ + e.red.X = API_cvt(rX); + e.red.Y = API_cvt(rY); + e.red.Z = API_cvt(rZ); + e.green.X = API_cvt(gX); + e.green.Y = API_cvt(gY); + e.green.Z = API_cvt(gZ); + e.blue.X = API_cvt(bX); + e.blue.Y = API_cvt(bY); + e.blue.Z = API_cvt(bZ); + + /* This should match the original one from the png_modifier, within + * the range permitted by the libpng fixed point representation. + */ + maxe = 0; + el = "-"; /* Set to element name with error */ + +# define CHECK(col,x)\ + {\ + double err = fabs(o.col.x - e.col.x);\ + if (err > maxe)\ + {\ + maxe = err;\ + el = #col "(" #x ")";\ + }\ + } + + CHECK(red,X) + CHECK(red,Y) + CHECK(red,Z) + CHECK(green,X) + CHECK(green,Y) + CHECK(green,Z) + CHECK(blue,X) + CHECK(blue,Y) + CHECK(blue,Z) + + /* Here in both fixed and floating cases to check the values read + * from the cHRm chunk. PNG uses fixed point in the cHRM chunk, so + * we can't expect better than +/-.5E-5 on the result, allow 1E-5. + */ + if (maxe >= 1E-5) + { + size_t pos = 0; + char buffer[256]; + + pos = safecat(buffer, sizeof buffer, pos, API_form); + pos = safecat(buffer, sizeof buffer, pos, " cHRM "); + pos = safecat(buffer, sizeof buffer, pos, el); + pos = safecat(buffer, sizeof buffer, pos, " error: "); + pos = safecatd(buffer, sizeof buffer, pos, maxe, 7); + pos = safecat(buffer, sizeof buffer, pos, " "); + /* Print the color space without the gamma value: */ + pos = safecat_color_encoding(buffer, sizeof buffer, pos, &o, 0); + pos = safecat(buffer, sizeof buffer, pos, " -> "); + pos = safecat_color_encoding(buffer, sizeof buffer, pos, &e, 0); + + png_error(pp, buffer); + } + } + } +# endif /* READ_cHRM */ + + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0) + { + double gray, err; + + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that); + + /* Image now has RGB channels... */ +# if DIGITIZE + { + PNG_CONST png_modifier *pm = display->pm; + const unsigned int sample_depth = that->sample_depth; + const unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 : + sample_depth); + const unsigned int gamma_depth = (sample_depth == 16 ? 16 : + (pm->assume_16_bit_calculations ? PNG_MAX_GAMMA_8 : sample_depth)); + int isgray; + double r, g, b; + double rlo, rhi, glo, ghi, blo, bhi, graylo, grayhi; + + /* Do this using interval arithmetic, otherwise it is too difficult to + * handle the errors correctly. + * + * To handle the gamma correction work out the upper and lower bounds + * of the digitized value. Assume rounding here - normally the values + * will be identical after this operation if there is only one + * transform, feel free to delete the png_error checks on this below in + * the future (this is just me trying to ensure it works!) + */ + r = rlo = rhi = that->redf; + rlo -= that->rede; + rlo = digitize(rlo, calc_depth, 1/*round*/); + rhi += that->rede; + rhi = digitize(rhi, calc_depth, 1/*round*/); + + g = glo = ghi = that->greenf; + glo -= that->greene; + glo = digitize(glo, calc_depth, 1/*round*/); + ghi += that->greene; + ghi = digitize(ghi, calc_depth, 1/*round*/); + + b = blo = bhi = that->bluef; + blo -= that->bluee; + blo = digitize(blo, calc_depth, 1/*round*/); + bhi += that->greene; + bhi = digitize(bhi, calc_depth, 1/*round*/); + + isgray = r==g && g==b; + + if (data.gamma != 1) + { + PNG_CONST double power = 1/data.gamma; + PNG_CONST double abse = calc_depth == 16 ? .5/65535 : .5/255; + + /* 'abse' is the absolute error permitted in linear calculations. It + * is used here to capture the error permitted in the handling + * (undoing) of the gamma encoding. Once again digitization occurs + * to handle the upper and lower bounds of the values. This is + * where the real errors are introduced. + */ + r = pow(r, power); + rlo = digitize(pow(rlo, power)-abse, calc_depth, 1); + rhi = digitize(pow(rhi, power)+abse, calc_depth, 1); + + g = pow(g, power); + glo = digitize(pow(glo, power)-abse, calc_depth, 1); + ghi = digitize(pow(ghi, power)+abse, calc_depth, 1); + + b = pow(b, power); + blo = digitize(pow(blo, power)-abse, calc_depth, 1); + bhi = digitize(pow(bhi, power)+abse, calc_depth, 1); + } + + /* Now calculate the actual gray values. Although the error in the + * coefficients depends on whether they were specified on the command + * line (in which case truncation to 15 bits happened) or not (rounding + * was used) the maxium error in an individual coefficient is always + * 1/32768, because even in the rounding case the requirement that + * coefficients add up to 32768 can cause a larger rounding error. + * + * The only time when rounding doesn't occur in 1.5.5 and later is when + * the non-gamma code path is used for less than 16 bit data. + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient; + + { + PNG_CONST int do_round = data.gamma != 1 || calc_depth == 16; + PNG_CONST double ce = 1. / 32768; + + graylo = digitize(rlo * (data.red_coefficient-ce) + + glo * (data.green_coefficient-ce) + + blo * (data.blue_coefficient-ce), gamma_depth, do_round); + if (graylo <= 0) + graylo = 0; + + grayhi = digitize(rhi * (data.red_coefficient+ce) + + ghi * (data.green_coefficient+ce) + + bhi * (data.blue_coefficient+ce), gamma_depth, do_round); + if (grayhi >= 1) + grayhi = 1; + } + + /* And invert the gamma. */ + if (data.gamma != 1) + { + PNG_CONST double power = data.gamma; + + gray = pow(gray, power); + graylo = digitize(pow(graylo, power), sample_depth, 1); + grayhi = digitize(pow(grayhi, power), sample_depth, 1); + } + + /* Now the error can be calculated. + * + * If r==g==b because there is no overall gamma correction libpng + * currently preserves the original value. + */ + if (isgray) + err = (that->rede + that->greene + that->bluee)/3; + + else + { + err = fabs(grayhi-gray); + if (fabs(gray - graylo) > err) + err = fabs(graylo-gray); + + /* Check that this worked: */ + if (err > pm->limit) + { + size_t pos = 0; + char buffer[128]; + + pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); + pos = safecatd(buffer, sizeof buffer, pos, err, 6); + pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); + pos = safecatd(buffer, sizeof buffer, pos, pm->limit, 6); + png_error(pp, buffer); + } + } + } +# else /* DIGITIZE */ + { + double r = that->redf; + double re = that->rede; + double g = that->greenf; + double ge = that->greene; + double b = that->bluef; + double be = that->bluee; + + /* The true gray case involves no math. */ + if (r == g && r == b) + { + gray = r; + err = re; + if (err < ge) err = ge; + if (err < be) err = be; + } + + else if (data.gamma == 1) + { + /* There is no need to do the conversions to and from linear space, + * so the calculation should be a lot more accurate. There is a + * built in 1/32768 error in the coefficients because they only have + * 15 bits and are adjusted to make sure they add up to 32768, so + * the result may have an additional error up to 1/32768. (Note + * that adding the 1/32768 here avoids needing to increase the + * global error limits to take this into account.) + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient; + err = re * data.red_coefficient + ge * data.green_coefficient + + be * data.blue_coefficient + 1./32768 + gray * 5 * DBL_EPSILON; + } + + else + { + /* The calculation happens in linear space, and this produces much + * wider errors in the encoded space. These are handled here by + * factoring the errors in to the calculation. There are two table + * lookups in the calculation and each introduces a quantization + * error defined by the table size. + */ + PNG_CONST png_modifier *pm = display->pm; + double in_qe = (that->sample_depth > 8 ? .5/65535 : .5/255); + double out_qe = (that->sample_depth > 8 ? .5/65535 : + (pm->assume_16_bit_calculations ? .5/(1<<PNG_MAX_GAMMA_8) : + .5/255)); + double rhi, ghi, bhi, grayhi; + double g1 = 1/data.gamma; + + rhi = r + re + in_qe; if (rhi > 1) rhi = 1; + r -= re + in_qe; if (r < 0) r = 0; + ghi = g + ge + in_qe; if (ghi > 1) ghi = 1; + g -= ge + in_qe; if (g < 0) g = 0; + bhi = b + be + in_qe; if (bhi > 1) bhi = 1; + b -= be + in_qe; if (b < 0) b = 0; + + r = pow(r, g1)*(1-DBL_EPSILON); rhi = pow(rhi, g1)*(1+DBL_EPSILON); + g = pow(g, g1)*(1-DBL_EPSILON); ghi = pow(ghi, g1)*(1+DBL_EPSILON); + b = pow(b, g1)*(1-DBL_EPSILON); bhi = pow(bhi, g1)*(1+DBL_EPSILON); + + /* Work out the lower and upper bounds for the gray value in the + * encoded space, then work out an average and error. Remove the + * previously added input quantization error at this point. + */ + gray = r * data.red_coefficient + g * data.green_coefficient + + b * data.blue_coefficient - 1./32768 - out_qe; + if (gray <= 0) + gray = 0; + else + { + gray *= (1 - 6 * DBL_EPSILON); + gray = pow(gray, data.gamma) * (1-DBL_EPSILON); + } + + grayhi = rhi * data.red_coefficient + ghi * data.green_coefficient + + bhi * data.blue_coefficient + 1./32768 + out_qe; + grayhi *= (1 + 6 * DBL_EPSILON); + if (grayhi >= 1) + grayhi = 1; + else + grayhi = pow(grayhi, data.gamma) * (1+DBL_EPSILON); + + err = (grayhi - gray) / 2; + gray = (grayhi + gray) / 2; + + if (err <= in_qe) + err = gray * DBL_EPSILON; + + else + err -= in_qe; + + /* Validate that the error is within limits (this has caused + * problems before, it's much easier to detect them here.) + */ + if (err > pm->limit) + { + size_t pos = 0; + char buffer[128]; + + pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); + pos = safecatd(buffer, sizeof buffer, pos, err, 6); + pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); + pos = safecatd(buffer, sizeof buffer, pos, pm->limit, 6); + png_error(pp, buffer); + } + } + } +# endif /* !DIGITIZE */ + + that->bluef = that->greenf = that->redf = gray; + that->bluee = that->greene = that->rede = err; + + /* The sBIT is the minium of the three colour channel sBITs. */ + if (that->red_sBIT > that->green_sBIT) + that->red_sBIT = that->green_sBIT; + if (that->red_sBIT > that->blue_sBIT) + that->red_sBIT = that->blue_sBIT; + that->blue_sBIT = that->green_sBIT = that->red_sBIT; + + /* And remove the colour bit in the type: */ + if (that->colour_type == PNG_COLOR_TYPE_RGB) + that->colour_type = PNG_COLOR_TYPE_GRAY; + else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_rgb_to_gray_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_COLOR) != 0; +} + +#undef data +IT(rgb_to_gray); +#undef PT +#define PT ITSTRUCT(rgb_to_gray) +#undef image_transform_ini +#define image_transform_ini image_transform_default_ini +#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */ + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* png_set_background(png_structp, png_const_color_16p background_color, + * int background_gamma_code, int need_expand, double background_gamma) + * png_set_background_fixed(png_structp, png_const_color_16p background_color, + * int background_gamma_code, int need_expand, + * png_fixed_point background_gamma) + * + * This ignores the gamma (at present.) +*/ +#define data ITDATA(background) +static image_pixel data; + +static void +image_transform_png_set_background_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_byte colour_type, bit_depth; + png_byte random_bytes[8]; /* 8 bytes - 64 bits - the biggest pixel */ + int expand; + png_color_16 back; + + /* We need a background colour, because we don't know exactly what transforms + * have been set we have to supply the colour in the original file format and + * so we need to know what that is! The background colour is stored in the + * transform_display. + */ + RANDOMIZE(random_bytes); + + /* Read the random value, for colour type 3 the background colour is actually + * expressed as a 24bit rgb, not an index. + */ + colour_type = that->this.colour_type; + if (colour_type == 3) + { + colour_type = PNG_COLOR_TYPE_RGB; + bit_depth = 8; + expand = 0; /* passing in an RGB not a pixel index */ + } + + else + { + bit_depth = that->this.bit_depth; + expand = 1; + } + + image_pixel_init(&data, random_bytes, colour_type, + bit_depth, 0/*x*/, 0/*unused: palette*/, NULL/*format*/); + + /* Extract the background colour from this image_pixel, but make sure the + * unused fields of 'back' are garbage. + */ + RANDOMIZE(back); + + if (colour_type & PNG_COLOR_MASK_COLOR) + { + back.red = (png_uint_16)data.red; + back.green = (png_uint_16)data.green; + back.blue = (png_uint_16)data.blue; + } + + else + back.gray = (png_uint_16)data.red; + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); +# else + png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); +# endif + + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_background_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + /* Check for tRNS first: */ + if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE) + image_pixel_add_alpha(that, &display->this); + + /* This is only necessary if the alpha value is less than 1. */ + if (that->alphaf < 1) + { + /* Now we do the background calculation without any gamma correction. */ + if (that->alphaf <= 0) + { + that->redf = data.redf; + that->greenf = data.greenf; + that->bluef = data.bluef; + + that->rede = data.rede; + that->greene = data.greene; + that->bluee = data.bluee; + + that->red_sBIT= data.red_sBIT; + that->green_sBIT= data.green_sBIT; + that->blue_sBIT= data.blue_sBIT; + } + + else /* 0 < alpha < 1 */ + { + double alf = 1 - that->alphaf; + + that->redf = that->redf * that->alphaf + data.redf * alf; + that->rede = that->rede * that->alphaf + data.rede * alf + + DBL_EPSILON; + that->greenf = that->greenf * that->alphaf + data.greenf * alf; + that->greene = that->greene * that->alphaf + data.greene * alf + + DBL_EPSILON; + that->bluef = that->bluef * that->alphaf + data.bluef * alf; + that->bluee = that->bluee * that->alphaf + data.bluee * alf + + DBL_EPSILON; + } + + /* Remove the alpha type and set the alpha (not in that order.) */ + that->alphaf = 1; + that->alphae = 0; + + if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB; + else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY; + /* PNG_COLOR_TYPE_PALETTE is not changed */ + } + + this->next->mod(this->next, that, pp, display); +} + +#define image_transform_png_set_background_add image_transform_default_add + +#undef data +IT(background); +#undef PT +#define PT ITSTRUCT(background) +#endif /* PNG_READ_BACKGROUND_SUPPORTED */ + +/* png_set_quantize(png_structp, png_colorp palette, int num_palette, + * int maximum_colors, png_const_uint_16p histogram, int full_quantize) + * + * Very difficult to validate this! + */ +/*NOTE: TBD NYI */ + +/* The data layout transforms are handled by swapping our own channel data, + * necessarily these need to happen at the end of the transform list because the + * semantic of the channels changes after these are executed. Some of these, + * like set_shift and set_packing, can't be done at present because they change + * the layout of the data at the sub-sample level so sample() won't get the + * right answer. + */ +/* png_set_invert_alpha */ +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED +/* Invert the alpha channel + * + * png_set_invert_alpha(png_structrp png_ptr) + */ +static void +image_transform_png_set_invert_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_invert_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_invert_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->colour_type & 4) + that->alpha_inverted = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_invert_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* Only has an effect on pixels with alpha: */ + return (colour_type & 4) != 0; +} + +IT(invert_alpha); +#undef PT +#define PT ITSTRUCT(invert_alpha) + +#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */ + +/* png_set_bgr */ +#ifdef PNG_READ_BGR_SUPPORTED +/* Swap R,G,B channels to order B,G,R. + * + * png_set_bgr(png_structrp png_ptr) + * + * This only has an effect on RGB and RGBA pixels. + */ +static void +image_transform_png_set_bgr_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_bgr(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_bgr_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_RGB || + that->colour_type == PNG_COLOR_TYPE_RGBA) + that->swap_rgb = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_bgr_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return colour_type == PNG_COLOR_TYPE_RGB || + colour_type == PNG_COLOR_TYPE_RGBA; +} + +IT(bgr); +#undef PT +#define PT ITSTRUCT(bgr) + +#endif /* PNG_READ_BGR_SUPPORTED */ + +/* png_set_swap_alpha */ +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED +/* Put the alpha channel first. + * + * png_set_swap_alpha(png_structrp png_ptr) + * + * This only has an effect on GA and RGBA pixels. + */ +static void +image_transform_png_set_swap_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_swap_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_swap_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_GA || + that->colour_type == PNG_COLOR_TYPE_RGBA) + that->alpha_first = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_swap_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return colour_type == PNG_COLOR_TYPE_GA || + colour_type == PNG_COLOR_TYPE_RGBA; +} + +IT(swap_alpha); +#undef PT +#define PT ITSTRUCT(swap_alpha) + +#endif /* PNG_READ_SWAP_ALPHA_SUPPORTED */ + +/* png_set_swap */ +#ifdef PNG_READ_SWAP_SUPPORTED +/* Byte swap 16-bit components. + * + * png_set_swap(png_structrp png_ptr) + */ +static void +image_transform_png_set_swap_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_swap(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_swap_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->bit_depth == 16) + that->swap16 = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_swap_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + return bit_depth == 16; +} + +IT(swap); +#undef PT +#define PT ITSTRUCT(swap) + +#endif /* PNG_READ_SWAP_SUPPORTED */ + +#ifdef PNG_READ_FILLER_SUPPORTED +/* Add a filler byte to 8-bit Gray or 24-bit RGB images. + * + * png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); + * + * Flags: + * + * PNG_FILLER_BEFORE + * PNG_FILLER_AFTER + */ +#define data ITDATA(filler) +static struct +{ + png_uint_32 filler; + int flags; +} data; + +static void +image_transform_png_set_filler_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + /* Need a random choice for 'before' and 'after' as well as for the + * filler. The 'filler' value has all 32 bits set, but only bit_depth + * will be used. At this point we don't know bit_depth. + */ + RANDOMIZE(data.filler); + data.flags = random_choice(); + + png_set_filler(pp, data.filler, data.flags); + + /* The standard display handling stuff also needs to know that + * there is a filler, so set that here. + */ + that->this.filler = 1; + + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_filler_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->bit_depth >= 8 && + (that->colour_type == PNG_COLOR_TYPE_RGB || + that->colour_type == PNG_COLOR_TYPE_GRAY)) + { + PNG_CONST unsigned int max = (1U << that->bit_depth)-1; + that->alpha = data.filler & max; + that->alphaf = ((double)that->alpha) / max; + that->alphae = 0; + + /* The filler has been stored in the alpha channel, we must record + * that this has been done for the checking later on, the color + * type is faked to have an alpha channel, but libpng won't report + * this; the app has to know the extra channel is there and this + * was recording in standard_display::filler above. + */ + that->colour_type |= 4; /* alpha added */ + that->alpha_first = data.flags == PNG_FILLER_BEFORE; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_filler_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + this->next = *that; + *that = this; + + return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB || + colour_type == PNG_COLOR_TYPE_GRAY); +} + +#undef data +IT(filler); +#undef PT +#define PT ITSTRUCT(filler) + +/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */ +/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ +#define data ITDATA(add_alpha) +static struct +{ + png_uint_32 filler; + int flags; +} data; + +static void +image_transform_png_set_add_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + /* Need a random choice for 'before' and 'after' as well as for the + * filler. The 'filler' value has all 32 bits set, but only bit_depth + * will be used. At this point we don't know bit_depth. + */ + RANDOMIZE(data.filler); + data.flags = random_choice(); + + png_set_add_alpha(pp, data.filler, data.flags); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_add_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->bit_depth >= 8 && + (that->colour_type == PNG_COLOR_TYPE_RGB || + that->colour_type == PNG_COLOR_TYPE_GRAY)) + { + PNG_CONST unsigned int max = (1U << that->bit_depth)-1; + that->alpha = data.filler & max; + that->alphaf = ((double)that->alpha) / max; + that->alphae = 0; + + that->colour_type |= 4; /* alpha added */ + that->alpha_first = data.flags == PNG_FILLER_BEFORE; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_add_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + this->next = *that; + *that = this; + + return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB || + colour_type == PNG_COLOR_TYPE_GRAY); +} + +#undef data +IT(add_alpha); +#undef PT +#define PT ITSTRUCT(add_alpha) + +#endif /* PNG_READ_FILLER_SUPPORTED */ + +/* png_set_packing */ +#ifdef PNG_READ_PACK_SUPPORTED +/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. + * + * png_set_packing(png_structrp png_ptr) + * + * This should only affect grayscale and palette images with less than 8 bits + * per pixel. + */ +static void +image_transform_png_set_packing_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_packing(pp); + that->unpacked = 1; + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_packing_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + /* The general expand case depends on what the colour type is, + * low bit-depth pixel values are unpacked into bytes without + * scaling, so sample_depth is not changed. + */ + if (that->bit_depth < 8) /* grayscale or palette */ + that->bit_depth = 8; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_packing_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + /* Nothing should happen unless the bit depth is less than 8: */ + return bit_depth < 8; +} + +IT(packing); +#undef PT +#define PT ITSTRUCT(packing) + +#endif /* PNG_READ_PACK_SUPPORTED */ + +/* png_set_packswap */ +#ifdef PNG_READ_PACKSWAP_SUPPORTED +/* Swap pixels packed into bytes; reverses the order on screen so that + * the high order bits correspond to the rightmost pixels. + * + * png_set_packswap(png_structrp png_ptr) + */ +static void +image_transform_png_set_packswap_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_packswap(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_packswap_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->bit_depth < 8) + that->littleendian = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_packswap_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + return bit_depth < 8; +} + +IT(packswap); +#undef PT +#define PT ITSTRUCT(packswap) + +#endif /* PNG_READ_PACKSWAP_SUPPORTED */ + + +/* png_set_invert_mono */ +#ifdef PNG_READ_INVERT_MONO_SUPPORTED +/* Invert the gray channel + * + * png_set_invert_mono(png_structrp png_ptr) + */ +static void +image_transform_png_set_invert_mono_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_invert_mono(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_invert_mono_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + if (that->colour_type & 4) + that->mono_inverted = 1; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_invert_mono_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* Only has an effect on pixels with no colour: */ + return (colour_type & 2) == 0; +} + +IT(invert_mono); +#undef PT +#define PT ITSTRUCT(invert_mono) + +#endif /* PNG_READ_INVERT_MONO_SUPPORTED */ + +#ifdef PNG_READ_SHIFT_SUPPORTED +/* png_set_shift(png_structp, png_const_color_8p true_bits) + * + * The output pixels will be shifted by the given true_bits + * values. + */ +#define data ITDATA(shift) +static png_color_8 data; + +static void +image_transform_png_set_shift_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + /* Get a random set of shifts. The shifts need to do something + * to test the transform, so they are limited to the bit depth + * of the input image. Notice that in the following the 'gray' + * field is randomized independently. This acts as a check that + * libpng does use the correct field. + */ + PNG_CONST unsigned int depth = that->this.bit_depth; + + data.red = (png_byte)/*SAFE*/(random_mod(depth)+1); + data.green = (png_byte)/*SAFE*/(random_mod(depth)+1); + data.blue = (png_byte)/*SAFE*/(random_mod(depth)+1); + data.gray = (png_byte)/*SAFE*/(random_mod(depth)+1); + data.alpha = (png_byte)/*SAFE*/(random_mod(depth)+1); + + png_set_shift(pp, &data); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_shift_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + /* Copy the correct values into the sBIT fields, libpng does not do + * anything to palette data: + */ + if (that->colour_type != PNG_COLOR_TYPE_PALETTE) + { + that->sig_bits = 1; + + /* The sBIT fields are reset to the values previously sent to + * png_set_shift according to the colour type. + * does. + */ + if (that->colour_type & 2) /* RGB channels */ + { + that->red_sBIT = data.red; + that->green_sBIT = data.green; + that->blue_sBIT = data.blue; + } + + else /* One grey channel */ + that->red_sBIT = that->green_sBIT = that->blue_sBIT = data.gray; + + that->alpha_sBIT = data.alpha; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_shift_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return colour_type != PNG_COLOR_TYPE_PALETTE; +} + +IT(shift); +#undef PT +#define PT ITSTRUCT(shift) + +#endif /* PNG_READ_SHIFT_SUPPORTED */ + +#ifdef THIS_IS_THE_PROFORMA +static void +image_transform_png_set_@_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_@(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_@_mod(PNG_CONST image_transform *this, + image_pixel *that, png_const_structp pp, + PNG_CONST transform_display *display) +{ + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_@_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + this->next = *that; + *that = this; + + return 1; +} + +IT(@); +#endif + + +/* This may just be 'end' if all the transforms are disabled! */ +static image_transform *PNG_CONST image_transform_first = &PT; + +static void +transform_enable(PNG_CONST char *name) +{ + /* Everything starts out enabled, so if we see an 'enable' disabled + * everything else the first time round. + */ + static int all_disabled = 0; + int found_it = 0; + image_transform *list = image_transform_first; + + while (list != &image_transform_end) + { + if (strcmp(list->name, name) == 0) + { + list->enable = 1; + found_it = 1; + } + else if (!all_disabled) + list->enable = 0; + + list = list->list; + } + + all_disabled = 1; + + if (!found_it) + { + fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n", + name); + exit(99); + } +} + +static void +transform_disable(PNG_CONST char *name) +{ + image_transform *list = image_transform_first; + + while (list != &image_transform_end) + { + if (strcmp(list->name, name) == 0) + { + list->enable = 0; + return; + } + + list = list->list; + } + + fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n", + name); + exit(99); +} + +static void +image_transform_reset_count(void) +{ + image_transform *next = image_transform_first; + int count = 0; + + while (next != &image_transform_end) + { + next->local_use = 0; + next->next = 0; + next = next->list; + ++count; + } + + /* This can only happen if we every have more than 32 transforms (excluding + * the end) in the list. + */ + if (count > 32) abort(); +} + +static int +image_transform_test_counter(png_uint_32 counter, unsigned int max) +{ + /* Test the list to see if there is any point contining, given a current + * counter and a 'max' value. + */ + image_transform *next = image_transform_first; + + while (next != &image_transform_end) + { + /* For max 0 or 1 continue until the counter overflows: */ + counter >>= 1; + + /* Continue if any entry hasn't reacked the max. */ + if (max > 1 && next->local_use < max) + return 1; + next = next->list; + } + + return max <= 1 && counter == 0; +} + +static png_uint_32 +image_transform_add(PNG_CONST image_transform **this, unsigned int max, + png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos, + png_byte colour_type, png_byte bit_depth) +{ + for (;;) /* until we manage to add something */ + { + png_uint_32 mask; + image_transform *list; + + /* Find the next counter value, if the counter is zero this is the start + * of the list. This routine always returns the current counter (not the + * next) so it returns 0 at the end and expects 0 at the beginning. + */ + if (counter == 0) /* first time */ + { + image_transform_reset_count(); + if (max <= 1) + counter = 1; + else + counter = random_32(); + } + else /* advance the counter */ + { + switch (max) + { + case 0: ++counter; break; + case 1: counter <<= 1; break; + default: counter = random_32(); break; + } + } + + /* Now add all these items, if possible */ + *this = &image_transform_end; + list = image_transform_first; + mask = 1; + + /* Go through the whole list adding anything that the counter selects: */ + while (list != &image_transform_end) + { + if ((counter & mask) != 0 && list->enable && + (max == 0 || list->local_use < max)) + { + /* Candidate to add: */ + if (list->add(list, this, colour_type, bit_depth) || max == 0) + { + /* Added, so add to the name too. */ + *pos = safecat(name, sizeof_name, *pos, " +"); + *pos = safecat(name, sizeof_name, *pos, list->name); + } + + else + { + /* Not useful and max>0, so remove it from *this: */ + *this = list->next; + list->next = 0; + + /* And, since we know it isn't useful, stop it being added again + * in this run: + */ + list->local_use = max; + } + } + + mask <<= 1; + list = list->list; + } + + /* Now if anything was added we have something to do. */ + if (*this != &image_transform_end) + return counter; + + /* Nothing added, but was there anything in there to add? */ + if (!image_transform_test_counter(counter, max)) + return 0; + } +} + +static void +perform_transform_test(png_modifier *pm) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + unsigned int palette_number = 0; + + while (next_format(&colour_type, &bit_depth, &palette_number, 0)) + { + png_uint_32 counter = 0; + size_t base_pos; + char name[64]; + + base_pos = safecat(name, sizeof name, 0, "transform:"); + + for (;;) + { + size_t pos = base_pos; + PNG_CONST image_transform *list = 0; + + /* 'max' is currently hardwired to '1'; this should be settable on the + * command line. + */ + counter = image_transform_add(&list, 1/*max*/, counter, + name, sizeof name, &pos, colour_type, bit_depth); + + if (counter == 0) + break; + + /* The command line can change this to checking interlaced images. */ + do + { + pm->repeat = 0; + transform_test(pm, FILEID(colour_type, bit_depth, palette_number, + pm->interlace_type, 0, 0, 0), list, name); + + if (fail(pm)) + return; + } + while (pm->repeat); + } + } +} +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +/********************************* GAMMA TESTS ********************************/ +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Reader callbacks and implementations, where they differ from the standard + * ones. + */ +typedef struct gamma_display +{ + standard_display this; + + /* Parameters */ + png_modifier* pm; + double file_gamma; + double screen_gamma; + double background_gamma; + png_byte sbit; + int threshold_test; + int use_input_precision; + int scale16; + int expand16; + int do_background; + png_color_16 background_color; + + /* Local variables */ + double maxerrout; + double maxerrpc; + double maxerrabs; +} gamma_display; + +#define ALPHA_MODE_OFFSET 4 + +static void +gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id, + double file_gamma, double screen_gamma, png_byte sbit, int threshold_test, + int use_input_precision, int scale16, int expand16, + int do_background, PNG_CONST png_color_16 *pointer_to_the_background_color, + double background_gamma) +{ + /* Standard fields */ + standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, + pm->use_update_info); + + /* Parameter fields */ + dp->pm = pm; + dp->file_gamma = file_gamma; + dp->screen_gamma = screen_gamma; + dp->background_gamma = background_gamma; + dp->sbit = sbit; + dp->threshold_test = threshold_test; + dp->use_input_precision = use_input_precision; + dp->scale16 = scale16; + dp->expand16 = expand16; + dp->do_background = do_background; + if (do_background && pointer_to_the_background_color != 0) + dp->background_color = *pointer_to_the_background_color; + else + memset(&dp->background_color, 0, sizeof dp->background_color); + + /* Local variable fields */ + dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0; +} + +static void +gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi) +{ + /* Reuse the standard stuff as appropriate. */ + standard_info_part1(&dp->this, pp, pi); + + /* If requested strip 16 to 8 bits - this is handled automagically below + * because the output bit depth is read from the library. Note that there + * are interactions with sBIT but, internally, libpng makes sbit at most + * PNG_MAX_GAMMA_8 when doing the following. + */ + if (dp->scale16) +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED + png_set_scale_16(pp); +# else + /* The following works both in 1.5.4 and earlier versions: */ +# ifdef PNG_READ_16_TO_8_SUPPORTED + png_set_strip_16(pp); +# else + png_error(pp, "scale16 (16 to 8 bit conversion) not supported"); +# endif +# endif + + if (dp->expand16) +# ifdef PNG_READ_EXPAND_16_SUPPORTED + png_set_expand_16(pp); +# else + png_error(pp, "expand16 (8 to 16 bit conversion) not supported"); +# endif + + if (dp->do_background >= ALPHA_MODE_OFFSET) + { +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED + { + /* This tests the alpha mode handling, if supported. */ + int mode = dp->do_background - ALPHA_MODE_OFFSET; + + /* The gamma value is the output gamma, and is in the standard, + * non-inverted, represenation. It provides a default for the PNG file + * gamma, but since the file has a gAMA chunk this does not matter. + */ + PNG_CONST double sg = dp->screen_gamma; +# ifndef PNG_FLOATING_POINT_SUPPORTED + PNG_CONST png_fixed_point g = fix(sg); +# endif + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_alpha_mode(pp, mode, sg); +# else + png_set_alpha_mode_fixed(pp, mode, g); +# endif + + /* However, for the standard Porter-Duff algorithm the output defaults + * to be linear, so if the test requires non-linear output it must be + * corrected here. + */ + if (mode == PNG_ALPHA_STANDARD && sg != 1) + { +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_gamma(pp, sg, dp->file_gamma); +# else + png_fixed_point f = fix(dp->file_gamma); + png_set_gamma_fixed(pp, g, f); +# endif + } + } +# else + png_error(pp, "alpha mode handling not supported"); +# endif + } + + else + { + /* Set up gamma processing. */ +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_gamma(pp, dp->screen_gamma, dp->file_gamma); +# else + { + png_fixed_point s = fix(dp->screen_gamma); + png_fixed_point f = fix(dp->file_gamma); + png_set_gamma_fixed(pp, s, f); + } +# endif + + if (dp->do_background) + { +# ifdef PNG_READ_BACKGROUND_SUPPORTED + /* NOTE: this assumes the caller provided the correct background gamma! + */ + PNG_CONST double bg = dp->background_gamma; +# ifndef PNG_FLOATING_POINT_SUPPORTED + PNG_CONST png_fixed_point g = fix(bg); +# endif + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_background(pp, &dp->background_color, dp->do_background, + 0/*need_expand*/, bg); +# else + png_set_background_fixed(pp, &dp->background_color, + dp->do_background, 0/*need_expand*/, g); +# endif +# else + png_error(pp, "png_set_background not supported"); +# endif + } + } + + { + int i = dp->this.use_update_info; + /* Always do one call, even if use_update_info is 0. */ + do + png_read_update_info(pp, pi); + while (--i > 0); + } + + /* Now we may get a different cbRow: */ + standard_info_part2(&dp->this, pp, pi, 1 /*images*/); +} + +static void PNGCBAPI +gamma_info(png_structp pp, png_infop pi) +{ + gamma_info_imp(voidcast(gamma_display*, png_get_progressive_ptr(pp)), pp, + pi); +} + +/* Validate a single component value - the routine gets the input and output + * sample values as unscaled PNG component values along with a cache of all the + * information required to validate the values. + */ +typedef struct validate_info +{ + png_const_structp pp; + gamma_display *dp; + png_byte sbit; + int use_input_precision; + int do_background; + int scale16; + unsigned int sbit_max; + unsigned int isbit_shift; + unsigned int outmax; + + double gamma_correction; /* Overall correction required. */ + double file_inverse; /* Inverse of file gamma. */ + double screen_gamma; + double screen_inverse; /* Inverse of screen gamma. */ + + double background_red; /* Linear background value, red or gray. */ + double background_green; + double background_blue; + + double maxabs; + double maxpc; + double maxcalc; + double maxout; + double maxout_total; /* Total including quantization error */ + double outlog; + int outquant; +} +validate_info; + +static void +init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp, + int in_depth, int out_depth) +{ + PNG_CONST unsigned int outmax = (1U<<out_depth)-1; + + vi->pp = pp; + vi->dp = dp; + + if (dp->sbit > 0 && dp->sbit < in_depth) + { + vi->sbit = dp->sbit; + vi->isbit_shift = in_depth - dp->sbit; + } + + else + { + vi->sbit = (png_byte)in_depth; + vi->isbit_shift = 0; + } + + vi->sbit_max = (1U << vi->sbit)-1; + + /* This mimics the libpng threshold test, '0' is used to prevent gamma + * correction in the validation test. + */ + vi->screen_gamma = dp->screen_gamma; + if (fabs(vi->screen_gamma-1) < PNG_GAMMA_THRESHOLD) + vi->screen_gamma = vi->screen_inverse = 0; + else + vi->screen_inverse = 1/vi->screen_gamma; + + vi->use_input_precision = dp->use_input_precision; + vi->outmax = outmax; + vi->maxabs = abserr(dp->pm, in_depth, out_depth); + vi->maxpc = pcerr(dp->pm, in_depth, out_depth); + vi->maxcalc = calcerr(dp->pm, in_depth, out_depth); + vi->maxout = outerr(dp->pm, in_depth, out_depth); + vi->outquant = output_quantization_factor(dp->pm, in_depth, out_depth); + vi->maxout_total = vi->maxout + vi->outquant * .5; + vi->outlog = outlog(dp->pm, in_depth, out_depth); + + if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 || + (dp->this.colour_type == 3 && dp->this.is_transparent)) + { + vi->do_background = dp->do_background; + + if (vi->do_background != 0) + { + PNG_CONST double bg_inverse = 1/dp->background_gamma; + double r, g, b; + + /* Caller must at least put the gray value into the red channel */ + r = dp->background_color.red; r /= outmax; + g = dp->background_color.green; g /= outmax; + b = dp->background_color.blue; b /= outmax; + +# if 0 + /* libpng doesn't do this optimization, if we do pngvalid will fail. + */ + if (fabs(bg_inverse-1) >= PNG_GAMMA_THRESHOLD) +# endif + { + r = pow(r, bg_inverse); + g = pow(g, bg_inverse); + b = pow(b, bg_inverse); + } + + vi->background_red = r; + vi->background_green = g; + vi->background_blue = b; + } + } + else + vi->do_background = 0; + + if (vi->do_background == 0) + vi->background_red = vi->background_green = vi->background_blue = 0; + + vi->gamma_correction = 1/(dp->file_gamma*dp->screen_gamma); + if (fabs(vi->gamma_correction-1) < PNG_GAMMA_THRESHOLD) + vi->gamma_correction = 0; + + vi->file_inverse = 1/dp->file_gamma; + if (fabs(vi->file_inverse-1) < PNG_GAMMA_THRESHOLD) + vi->file_inverse = 0; + + vi->scale16 = dp->scale16; +} + +/* This function handles composition of a single non-alpha component. The + * argument is the input sample value, in the range 0..1, and the alpha value. + * The result is the composed, linear, input sample. If alpha is less than zero + * this is the alpha component and the function should not be called! + */ +static double +gamma_component_compose(int do_background, double input_sample, double alpha, + double background, int *compose) +{ + switch (do_background) + { +#ifdef PNG_READ_BACKGROUND_SUPPORTED + case PNG_BACKGROUND_GAMMA_SCREEN: + case PNG_BACKGROUND_GAMMA_FILE: + case PNG_BACKGROUND_GAMMA_UNIQUE: + /* Standard PNG background processing. */ + if (alpha < 1) + { + if (alpha > 0) + { + input_sample = input_sample * alpha + background * (1-alpha); + if (compose != NULL) + *compose = 1; + } + + else + input_sample = background; + } + break; +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: + case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: + /* The components are premultiplied in either case and the output is + * gamma encoded (to get standard Porter-Duff we expect the output + * gamma to be set to 1.0!) + */ + case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: + /* The optimization is that the partial-alpha entries are linear + * while the opaque pixels are gamma encoded, but this only affects the + * output encoding. + */ + if (alpha < 1) + { + if (alpha > 0) + { + input_sample *= alpha; + if (compose != NULL) + *compose = 1; + } + + else + input_sample = 0; + } + break; +#endif + + default: + /* Standard cases where no compositing is done (so the component + * value is already correct.) + */ + UNUSED(alpha) + UNUSED(background) + UNUSED(compose) + break; + } + + return input_sample; +} + +/* This API returns the encoded *input* component, in the range 0..1 */ +static double +gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi, + PNG_CONST unsigned int id, PNG_CONST unsigned int od, + PNG_CONST double alpha /* <0 for the alpha channel itself */, + PNG_CONST double background /* component background value */) +{ + PNG_CONST unsigned int isbit = id >> vi->isbit_shift; + PNG_CONST unsigned int sbit_max = vi->sbit_max; + PNG_CONST unsigned int outmax = vi->outmax; + PNG_CONST int do_background = vi->do_background; + + double i; + + /* First check on the 'perfect' result obtained from the digitized input + * value, id, and compare this against the actual digitized result, 'od'. + * 'i' is the input result in the range 0..1: + */ + i = isbit; i /= sbit_max; + + /* Check for the fast route: if we don't do any background composition or if + * this is the alpha channel ('alpha' < 0) or if the pixel is opaque then + * just use the gamma_correction field to correct to the final output gamma. + */ + if (alpha == 1 /* opaque pixel component */ || !do_background +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + || do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG +#endif + || (alpha < 0 /* alpha channel */ +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + && do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN +#endif + )) + { + /* Then get the gamma corrected version of 'i' and compare to 'od', any + * error less than .5 is insignificant - just quantization of the output + * value to the nearest digital value (nevertheless the error is still + * recorded - it's interesting ;-) + */ + double encoded_sample = i; + double encoded_error; + + /* alpha less than 0 indicates the alpha channel, which is always linear + */ + if (alpha >= 0 && vi->gamma_correction > 0) + encoded_sample = pow(encoded_sample, vi->gamma_correction); + encoded_sample *= outmax; + + encoded_error = fabs(od-encoded_sample); + + if (encoded_error > vi->dp->maxerrout) + vi->dp->maxerrout = encoded_error; + + if (encoded_error < vi->maxout_total && encoded_error < vi->outlog) + return i; + } + + /* The slow route - attempt to do linear calculations. */ + /* There may be an error, or background processing is required, so calculate + * the actual sample values - unencoded light intensity values. Note that in + * practice these are not completely unencoded because they include a + * 'viewing correction' to decrease or (normally) increase the perceptual + * contrast of the image. There's nothing we can do about this - we don't + * know what it is - so assume the unencoded value is perceptually linear. + */ + { + double input_sample = i; /* In range 0..1 */ + double output, error, encoded_sample, encoded_error; + double es_lo, es_hi; + int compose = 0; /* Set to one if composition done */ + int output_is_encoded; /* Set if encoded to screen gamma */ + int log_max_error = 1; /* Check maximum error values */ + png_const_charp pass = 0; /* Reason test passes (or 0 for fail) */ + + /* Convert to linear light (with the above caveat.) The alpha channel is + * already linear. + */ + if (alpha >= 0) + { + int tcompose; + + if (vi->file_inverse > 0) + input_sample = pow(input_sample, vi->file_inverse); + + /* Handle the compose processing: */ + tcompose = 0; + input_sample = gamma_component_compose(do_background, input_sample, + alpha, background, &tcompose); + + if (tcompose) + compose = 1; + } + + /* And similarly for the output value, but we need to check the background + * handling to linearize it correctly. + */ + output = od; + output /= outmax; + + output_is_encoded = vi->screen_gamma > 0; + + if (alpha < 0) /* The alpha channel */ + { +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN) +#endif + { + /* In all other cases the output alpha channel is linear already, + * don't log errors here, they are much larger in linear data. + */ + output_is_encoded = 0; + log_max_error = 0; + } + } + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + else /* A component */ + { + if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED && + alpha < 1) /* the optimized case - linear output */ + { + if (alpha > 0) log_max_error = 0; + output_is_encoded = 0; + } + } +#endif + + if (output_is_encoded) + output = pow(output, vi->screen_gamma); + + /* Calculate (or recalculate) the encoded_sample value and repeat the + * check above (unnecessary if we took the fast route, but harmless.) + */ + encoded_sample = input_sample; + if (output_is_encoded) + encoded_sample = pow(encoded_sample, vi->screen_inverse); + encoded_sample *= outmax; + + encoded_error = fabs(od-encoded_sample); + + /* Don't log errors in the alpha channel, or the 'optimized' case, + * neither are significant to the overall perception. + */ + if (log_max_error && encoded_error > vi->dp->maxerrout) + vi->dp->maxerrout = encoded_error; + + if (encoded_error < vi->maxout_total) + { + if (encoded_error < vi->outlog) + return i; + + /* Test passed but error is bigger than the log limit, record why the + * test passed: + */ + pass = "less than maxout:\n"; + } + + /* i: the original input value in the range 0..1 + * + * pngvalid calculations: + * input_sample: linear result; i linearized and composed, range 0..1 + * encoded_sample: encoded result; input_sample scaled to ouput bit depth + * + * libpng calculations: + * output: linear result; od scaled to 0..1 and linearized + * od: encoded result from libpng + */ + + /* Now we have the numbers for real errors, both absolute values as as a + * percentage of the correct value (output): + */ + error = fabs(input_sample-output); + + if (log_max_error && error > vi->dp->maxerrabs) + vi->dp->maxerrabs = error; + + /* The following is an attempt to ignore the tendency of quantization to + * dominate the percentage errors for lower result values: + */ + if (log_max_error && input_sample > .5) + { + double percentage_error = error/input_sample; + if (percentage_error > vi->dp->maxerrpc) + vi->dp->maxerrpc = percentage_error; + } + + /* Now calculate the digitization limits for 'encoded_sample' using the + * 'max' values. Note that maxout is in the encoded space but maxpc and + * maxabs are in linear light space. + * + * First find the maximum error in linear light space, range 0..1: + */ + { + double tmp = input_sample * vi->maxpc; + if (tmp < vi->maxabs) tmp = vi->maxabs; + /* If 'compose' is true the composition was done in linear space using + * integer arithmetic. This introduces an extra error of +/- 0.5 (at + * least) in the integer space used. 'maxcalc' records this, taking + * into account the possibility that even for 16 bit output 8 bit space + * may have been used. + */ + if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc; + + /* The 'maxout' value refers to the encoded result, to compare with + * this encode input_sample adjusted by the maximum error (tmp) above. + */ + es_lo = encoded_sample - vi->maxout; + + if (es_lo > 0 && input_sample-tmp > 0) + { + double low_value = input_sample-tmp; + if (output_is_encoded) + low_value = pow(low_value, vi->screen_inverse); + low_value *= outmax; + if (low_value < es_lo) es_lo = low_value; + + /* Quantize this appropriately: */ + es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant; + } + + else + es_lo = 0; + + es_hi = encoded_sample + vi->maxout; + + if (es_hi < outmax && input_sample+tmp < 1) + { + double high_value = input_sample+tmp; + if (output_is_encoded) + high_value = pow(high_value, vi->screen_inverse); + high_value *= outmax; + if (high_value > es_hi) es_hi = high_value; + + es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant; + } + + else + es_hi = outmax; + } + + /* The primary test is that the final encoded value returned by the + * library should be between the two limits (inclusive) that were + * calculated above. + */ + if (od >= es_lo && od <= es_hi) + { + /* The value passes, but we may need to log the information anyway. */ + if (encoded_error < vi->outlog) + return i; + + if (pass == 0) + pass = "within digitization limits:\n"; + } + + { + /* There has been an error in processing, or we need to log this + * value. + */ + double is_lo, is_hi; + + /* pass is set at this point if either of the tests above would have + * passed. Don't do these additional tests here - just log the + * original [es_lo..es_hi] values. + */ + if (pass == 0 && vi->use_input_precision && vi->dp->sbit) + { + /* Ok, something is wrong - this actually happens in current libpng + * 16-to-8 processing. Assume that the input value (id, adjusted + * for sbit) can be anywhere between value-.5 and value+.5 - quite a + * large range if sbit is low. + * + * NOTE: at present because the libpng gamma table stuff has been + * changed to use a rounding algorithm to correct errors in 8-bit + * calculations the precise sbit calculation (a shift) has been + * lost. This can result in up to a +/-1 error in the presence of + * an sbit less than the bit depth. + */ +# if PNG_LIBPNG_VER < 10700 +# define SBIT_ERROR .5 +# else +# define SBIT_ERROR 1. +# endif + double tmp = (isbit - SBIT_ERROR)/sbit_max; + + if (tmp <= 0) + tmp = 0; + + else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) + tmp = pow(tmp, vi->file_inverse); + + tmp = gamma_component_compose(do_background, tmp, alpha, background, + NULL); + + if (output_is_encoded && tmp > 0 && tmp < 1) + tmp = pow(tmp, vi->screen_inverse); + + is_lo = ceil(outmax * tmp - vi->maxout_total); + + if (is_lo < 0) + is_lo = 0; + + tmp = (isbit + SBIT_ERROR)/sbit_max; + + if (tmp >= 1) + tmp = 1; + + else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) + tmp = pow(tmp, vi->file_inverse); + + tmp = gamma_component_compose(do_background, tmp, alpha, background, + NULL); + + if (output_is_encoded && tmp > 0 && tmp < 1) + tmp = pow(tmp, vi->screen_inverse); + + is_hi = floor(outmax * tmp + vi->maxout_total); + + if (is_hi > outmax) + is_hi = outmax; + + if (!(od < is_lo || od > is_hi)) + { + if (encoded_error < vi->outlog) + return i; + + pass = "within input precision limits:\n"; + } + + /* One last chance. If this is an alpha channel and the 16to8 + * option has been used and 'inaccurate' scaling is used then the + * bit reduction is obtained by simply using the top 8 bits of the + * value. + * + * This is only done for older libpng versions when the 'inaccurate' + * (chop) method of scaling was used. + */ +# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +# if PNG_LIBPNG_VER < 10504 + /* This may be required for other components in the future, + * but at present the presence of gamma correction effectively + * prevents the errors in the component scaling (I don't quite + * understand why, but since it's better this way I care not + * to ask, JB 20110419.) + */ + if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 && + vi->sbit + vi->isbit_shift == 16) + { + tmp = ((id >> 8) - .5)/255; + + if (tmp > 0) + { + is_lo = ceil(outmax * tmp - vi->maxout_total); + if (is_lo < 0) is_lo = 0; + } + + else + is_lo = 0; + + tmp = ((id >> 8) + .5)/255; + + if (tmp < 1) + { + is_hi = floor(outmax * tmp + vi->maxout_total); + if (is_hi > outmax) is_hi = outmax; + } + + else + is_hi = outmax; + + if (!(od < is_lo || od > is_hi)) + { + if (encoded_error < vi->outlog) + return i; + + pass = "within 8 bit limits:\n"; + } + } +# endif +# endif + } + else /* !use_input_precision */ + is_lo = es_lo, is_hi = es_hi; + + /* Attempt to output a meaningful error/warning message: the message + * output depends on the background/composite operation being performed + * because this changes what parameters were actually used above. + */ + { + size_t pos = 0; + /* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal + * places. Just use outmax to work out which. + */ + int precision = (outmax >= 1000 ? 6 : 3); + int use_input=1, use_background=0, do_compose=0; + char msg[256]; + + if (pass != 0) + pos = safecat(msg, sizeof msg, pos, "\n\t"); + + /* Set up the various flags, the output_is_encoded flag above + * is also used below. do_compose is just a double check. + */ + switch (do_background) + { +# ifdef PNG_READ_BACKGROUND_SUPPORTED + case PNG_BACKGROUND_GAMMA_SCREEN: + case PNG_BACKGROUND_GAMMA_FILE: + case PNG_BACKGROUND_GAMMA_UNIQUE: + use_background = (alpha >= 0 && alpha < 1); + /*FALL THROUGH*/ +# endif +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED + case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: + case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: + case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: +# endif /* ALPHA_MODE_SUPPORTED */ + do_compose = (alpha > 0 && alpha < 1); + use_input = (alpha != 0); + break; + + default: + break; + } + + /* Check the 'compose' flag */ + if (compose != do_compose) + png_error(vi->pp, "internal error (compose)"); + + /* 'name' is the component name */ + pos = safecat(msg, sizeof msg, pos, name); + pos = safecat(msg, sizeof msg, pos, "("); + pos = safecatn(msg, sizeof msg, pos, id); + if (use_input || pass != 0/*logging*/) + { + if (isbit != id) + { + /* sBIT has reduced the precision of the input: */ + pos = safecat(msg, sizeof msg, pos, ", sbit("); + pos = safecatn(msg, sizeof msg, pos, vi->sbit); + pos = safecat(msg, sizeof msg, pos, "): "); + pos = safecatn(msg, sizeof msg, pos, isbit); + } + pos = safecat(msg, sizeof msg, pos, "/"); + /* The output is either "id/max" or "id sbit(sbit): isbit/max" */ + pos = safecatn(msg, sizeof msg, pos, vi->sbit_max); + } + pos = safecat(msg, sizeof msg, pos, ")"); + + /* A component may have been multiplied (in linear space) by the + * alpha value, 'compose' says whether this is relevant. + */ + if (compose || pass != 0) + { + /* If any form of composition is being done report our + * calculated linear value here (the code above doesn't record + * the input value before composition is performed, so what + * gets reported is the value after composition.) + */ + if (use_input || pass != 0) + { + if (vi->file_inverse > 0) + { + pos = safecat(msg, sizeof msg, pos, "^"); + pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2); + } + + else + pos = safecat(msg, sizeof msg, pos, "[linear]"); + + pos = safecat(msg, sizeof msg, pos, "*(alpha)"); + pos = safecatd(msg, sizeof msg, pos, alpha, precision); + } + + /* Now record the *linear* background value if it was used + * (this function is not passed the original, non-linear, + * value but it is contained in the test name.) + */ + if (use_background) + { + pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " "); + pos = safecat(msg, sizeof msg, pos, "(background)"); + pos = safecatd(msg, sizeof msg, pos, background, precision); + pos = safecat(msg, sizeof msg, pos, "*"); + pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision); + } + } + + /* Report the calculated value (input_sample) and the linearized + * libpng value (output) unless this is just a component gamma + * correction. + */ + if (compose || alpha < 0 || pass != 0) + { + pos = safecat(msg, sizeof msg, pos, + pass != 0 ? " =\n\t" : " = "); + pos = safecatd(msg, sizeof msg, pos, input_sample, precision); + pos = safecat(msg, sizeof msg, pos, " (libpng: "); + pos = safecatd(msg, sizeof msg, pos, output, precision); + pos = safecat(msg, sizeof msg, pos, ")"); + + /* Finally report the output gamma encoding, if any. */ + if (output_is_encoded) + { + pos = safecat(msg, sizeof msg, pos, " ^"); + pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2); + pos = safecat(msg, sizeof msg, pos, "(to screen) ="); + } + + else + pos = safecat(msg, sizeof msg, pos, " [screen is linear] ="); + } + + if ((!compose && alpha >= 0) || pass != 0) + { + if (pass != 0) /* logging */ + pos = safecat(msg, sizeof msg, pos, "\n\t[overall:"); + + /* This is the non-composition case, the internal linear + * values are irrelevant (though the log below will reveal + * them.) Output a much shorter warning/error message and report + * the overall gamma correction. + */ + if (vi->gamma_correction > 0) + { + pos = safecat(msg, sizeof msg, pos, " ^"); + pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2); + pos = safecat(msg, sizeof msg, pos, "(gamma correction) ="); + } + + else + pos = safecat(msg, sizeof msg, pos, + " [no gamma correction] ="); + + if (pass != 0) + pos = safecat(msg, sizeof msg, pos, "]"); + } + + /* This is our calculated encoded_sample which should (but does + * not) match od: + */ + pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " "); + pos = safecatd(msg, sizeof msg, pos, is_lo, 1); + pos = safecat(msg, sizeof msg, pos, " < "); + pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1); + pos = safecat(msg, sizeof msg, pos, " (libpng: "); + pos = safecatn(msg, sizeof msg, pos, od); + pos = safecat(msg, sizeof msg, pos, ")"); + pos = safecat(msg, sizeof msg, pos, "/"); + pos = safecatn(msg, sizeof msg, pos, outmax); + pos = safecat(msg, sizeof msg, pos, " < "); + pos = safecatd(msg, sizeof msg, pos, is_hi, 1); + + if (pass == 0) /* The error condition */ + { +# ifdef PNG_WARNINGS_SUPPORTED + png_warning(vi->pp, msg); +# else + store_warning(vi->pp, msg); +# endif + } + + else /* logging this value */ + store_verbose(&vi->dp->pm->this, vi->pp, pass, msg); + } + } + } + + return i; +} + +static void +gamma_image_validate(gamma_display *dp, png_const_structp pp, + png_infop pi) +{ + /* Get some constants derived from the input and output file formats: */ + PNG_CONST png_store* PNG_CONST ps = dp->this.ps; + PNG_CONST png_byte in_ct = dp->this.colour_type; + PNG_CONST png_byte in_bd = dp->this.bit_depth; + PNG_CONST png_uint_32 w = dp->this.w; + PNG_CONST png_uint_32 h = dp->this.h; + PNG_CONST size_t cbRow = dp->this.cbRow; + PNG_CONST png_byte out_ct = png_get_color_type(pp, pi); + PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi); + + /* There are three sources of error, firstly the quantization in the + * file encoding, determined by sbit and/or the file depth, secondly + * the output (screen) gamma and thirdly the output file encoding. + * + * Since this API receives the screen and file gamma in double + * precision it is possible to calculate an exact answer given an input + * pixel value. Therefore we assume that the *input* value is exact - + * sample/maxsample - calculate the corresponding gamma corrected + * output to the limits of double precision arithmetic and compare with + * what libpng returns. + * + * Since the library must quantize the output to 8 or 16 bits there is + * a fundamental limit on the accuracy of the output of +/-.5 - this + * quantization limit is included in addition to the other limits + * specified by the paramaters to the API. (Effectively, add .5 + * everywhere.) + * + * The behavior of the 'sbit' paramter is defined by section 12.5 + * (sample depth scaling) of the PNG spec. That section forces the + * decoder to assume that the PNG values have been scaled if sBIT is + * present: + * + * png-sample = floor( input-sample * (max-out/max-in) + .5); + * + * This means that only a subset of the possible PNG values should + * appear in the input. However, the spec allows the encoder to use a + * variety of approximations to the above and doesn't require any + * restriction of the values produced. + * + * Nevertheless the spec requires that the upper 'sBIT' bits of the + * value stored in a PNG file be the original sample bits. + * Consequently the code below simply scales the top sbit bits by + * (1<<sbit)-1 to obtain an original sample value. + * + * Because there is limited precision in the input it is arguable that + * an acceptable result is any valid result from input-.5 to input+.5. + * The basic tests below do not do this, however if 'use_input_precision' + * is set a subsequent test is performed above. + */ + PNG_CONST unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U; + int processing; + png_uint_32 y; + PNG_CONST store_palette_entry *in_palette = dp->this.palette; + PNG_CONST int in_is_transparent = dp->this.is_transparent; + int out_npalette = -1; + int out_is_transparent = 0; /* Just refers to the palette case */ + store_palette out_palette; + validate_info vi; + + /* Check for row overwrite errors */ + store_image_check(dp->this.ps, pp, 0); + + /* Supply the input and output sample depths here - 8 for an indexed image, + * otherwise the bit depth. + */ + init_validate_info(&vi, dp, pp, in_ct==3?8:in_bd, out_ct==3?8:out_bd); + + processing = (vi.gamma_correction > 0 && !dp->threshold_test) + || in_bd != out_bd || in_ct != out_ct || vi.do_background; + + /* TODO: FIX THIS: MAJOR BUG! If the transformations all happen inside + * the palette there is no way of finding out, because libpng fails to + * update the palette on png_read_update_info. Indeed, libpng doesn't + * even do the required work until much later, when it doesn't have any + * info pointer. Oops. For the moment 'processing' is turned off if + * out_ct is palette. + */ + if (in_ct == 3 && out_ct == 3) + processing = 0; + + if (processing && out_ct == 3) + out_is_transparent = read_palette(out_palette, &out_npalette, pp, pi); + + for (y=0; y<h; ++y) + { + png_const_bytep pRow = store_image_row(ps, pp, 0, y); + png_byte std[STANDARD_ROWMAX]; + + transform_row(pp, std, in_ct, in_bd, y); + + if (processing) + { + unsigned int x; + + for (x=0; x<w; ++x) + { + double alpha = 1; /* serves as a flag value */ + + /* Record the palette index for index images. */ + PNG_CONST unsigned int in_index = + in_ct == 3 ? sample(std, 3, in_bd, x, 0, 0, 0) : 256; + PNG_CONST unsigned int out_index = + out_ct == 3 ? sample(std, 3, out_bd, x, 0, 0, 0) : 256; + + /* Handle input alpha - png_set_background will cause the output + * alpha to disappear so there is nothing to check. + */ + if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 || (in_ct == 3 && + in_is_transparent)) + { + PNG_CONST unsigned int input_alpha = in_ct == 3 ? + dp->this.palette[in_index].alpha : + sample(std, in_ct, in_bd, x, samples_per_pixel, 0, 0); + + unsigned int output_alpha = 65536 /* as a flag value */; + + if (out_ct == 3) + { + if (out_is_transparent) + output_alpha = out_palette[out_index].alpha; + } + + else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0) + output_alpha = sample(pRow, out_ct, out_bd, x, + samples_per_pixel, 0, 0); + + if (output_alpha != 65536) + alpha = gamma_component_validate("alpha", &vi, input_alpha, + output_alpha, -1/*alpha*/, 0/*background*/); + + else /* no alpha in output */ + { + /* This is a copy of the calculation of 'i' above in order to + * have the alpha value to use in the background calculation. + */ + alpha = input_alpha >> vi.isbit_shift; + alpha /= vi.sbit_max; + } + } + + /* Handle grayscale or RGB components. */ + if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */ + (void)gamma_component_validate("gray", &vi, + sample(std, in_ct, in_bd, x, 0, 0, 0), + sample(pRow, out_ct, out_bd, x, 0, 0, 0), + alpha/*component*/, vi.background_red); + else /* RGB or palette */ + { + (void)gamma_component_validate("red", &vi, + in_ct == 3 ? in_palette[in_index].red : + sample(std, in_ct, in_bd, x, 0, 0, 0), + out_ct == 3 ? out_palette[out_index].red : + sample(pRow, out_ct, out_bd, x, 0, 0, 0), + alpha/*component*/, vi.background_red); + + (void)gamma_component_validate("green", &vi, + in_ct == 3 ? in_palette[in_index].green : + sample(std, in_ct, in_bd, x, 1, 0, 0), + out_ct == 3 ? out_palette[out_index].green : + sample(pRow, out_ct, out_bd, x, 1, 0, 0), + alpha/*component*/, vi.background_green); + + (void)gamma_component_validate("blue", &vi, + in_ct == 3 ? in_palette[in_index].blue : + sample(std, in_ct, in_bd, x, 2, 0, 0), + out_ct == 3 ? out_palette[out_index].blue : + sample(pRow, out_ct, out_bd, x, 2, 0, 0), + alpha/*component*/, vi.background_blue); + } + } + } + + else if (memcmp(std, pRow, cbRow) != 0) + { + char msg[64]; + + /* No transform is expected on the threshold tests. */ + sprintf(msg, "gamma: below threshold row %lu changed", + (unsigned long)y); + + png_error(pp, msg); + } + } /* row (y) loop */ + + dp->this.ps->validated = 1; +} + +static void PNGCBAPI +gamma_end(png_structp ppIn, png_infop pi) +{ + png_const_structp pp = ppIn; + gamma_display *dp = voidcast(gamma_display*, png_get_progressive_ptr(pp)); + + if (!dp->this.speed) + gamma_image_validate(dp, pp, pi); + else + dp->this.ps->validated = 1; +} + +/* A single test run checking a gamma transformation. + * + * maxabs: maximum absolute error as a fraction + * maxout: maximum output error in the output units + * maxpc: maximum percentage error (as a percentage) + */ +static void +gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn, + PNG_CONST png_byte bit_depthIn, PNG_CONST int palette_numberIn, + PNG_CONST int interlace_typeIn, + PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn, + PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn, + PNG_CONST char *name, + PNG_CONST int use_input_precisionIn, PNG_CONST int scale16In, + PNG_CONST int expand16In, PNG_CONST int do_backgroundIn, + PNG_CONST png_color_16 *bkgd_colorIn, double bkgd_gammaIn) +{ + gamma_display d; + context(&pmIn->this, fault); + + gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn, + palette_numberIn, interlace_typeIn, 0, 0, 0), + file_gammaIn, screen_gammaIn, sbitIn, + threshold_testIn, use_input_precisionIn, scale16In, + expand16In, do_backgroundIn, bkgd_colorIn, bkgd_gammaIn); + + Try + { + png_structp pp; + png_infop pi; + gama_modification gama_mod; + srgb_modification srgb_mod; + sbit_modification sbit_mod; + + /* For the moment don't use the png_modifier support here. */ + d.pm->encoding_counter = 0; + modifier_set_encoding(d.pm); /* Just resets everything */ + d.pm->current_gamma = d.file_gamma; + + /* Make an appropriate modifier to set the PNG file gamma to the + * given gamma value and the sBIT chunk to the given precision. + */ + d.pm->modifications = NULL; + gama_modification_init(&gama_mod, d.pm, d.file_gamma); + srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/); + if (d.sbit > 0) + sbit_modification_init(&sbit_mod, d.pm, d.sbit); + + modification_reset(d.pm->modifications); + + /* Get a png_struct for writing the image. */ + pp = set_modifier_for_read(d.pm, &pi, d.this.id, name); + standard_palette_init(&d.this); + + /* Introduce the correct read function. */ + if (d.pm->this.progressive) + { + /* Share the row function with the standard implementation. */ + png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row, + gamma_end); + + /* Now feed data into the reader until we reach the end: */ + modifier_progressive_read(d.pm, pp, pi); + } + else + { + /* modifier_read expects a png_modifier* */ + png_set_read_fn(pp, d.pm, modifier_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* Process the 'info' requirements. Only one image is generated */ + gamma_info_imp(&d, pp, pi); + + sequential_row(&d.this, pp, pi, -1, 0); + + if (!d.this.speed) + gamma_image_validate(&d, pp, pi); + else + d.this.ps->validated = 1; + } + + modifier_reset(d.pm); + + if (d.pm->log && !d.threshold_test && !d.this.speed) + fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n", + d.this.bit_depth, colour_types[d.this.colour_type], name, + d.maxerrout, d.maxerrabs, 100*d.maxerrpc); + + /* Log the summary values too. */ + if (d.this.colour_type == 0 || d.this.colour_type == 4) + { + switch (d.this.bit_depth) + { + case 1: + break; + + case 2: + if (d.maxerrout > d.pm->error_gray_2) + d.pm->error_gray_2 = d.maxerrout; + + break; + + case 4: + if (d.maxerrout > d.pm->error_gray_4) + d.pm->error_gray_4 = d.maxerrout; + + break; + + case 8: + if (d.maxerrout > d.pm->error_gray_8) + d.pm->error_gray_8 = d.maxerrout; + + break; + + case 16: + if (d.maxerrout > d.pm->error_gray_16) + d.pm->error_gray_16 = d.maxerrout; + + break; + + default: + png_error(pp, "bad bit depth (internal: 1)"); + } + } + + else if (d.this.colour_type == 2 || d.this.colour_type == 6) + { + switch (d.this.bit_depth) + { + case 8: + + if (d.maxerrout > d.pm->error_color_8) + d.pm->error_color_8 = d.maxerrout; + + break; + + case 16: + + if (d.maxerrout > d.pm->error_color_16) + d.pm->error_color_16 = d.maxerrout; + + break; + + default: + png_error(pp, "bad bit depth (internal: 2)"); + } + } + + else if (d.this.colour_type == 3) + { + if (d.maxerrout > d.pm->error_indexed) + d.pm->error_indexed = d.maxerrout; + } + } + + Catch(fault) + modifier_reset(voidcast(png_modifier*,(void*)fault)); +} + +static void gamma_threshold_test(png_modifier *pm, png_byte colour_type, + png_byte bit_depth, int interlace_type, double file_gamma, + double screen_gamma) +{ + size_t pos = 0; + char name[64]; + pos = safecat(name, sizeof name, pos, "threshold "); + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "/"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + (void)gamma_test(pm, colour_type, bit_depth, 0/*palette*/, interlace_type, + file_gamma, screen_gamma, 0/*sBIT*/, 1/*threshold test*/, name, + 0 /*no input precision*/, + 0 /*no scale16*/, 0 /*no expand16*/, 0 /*no background*/, 0 /*hence*/, + 0 /*no background gamma*/); +} + +static void +perform_gamma_threshold_tests(png_modifier *pm) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + unsigned int palette_number = 0; + + /* Don't test more than one instance of each palette - it's pointless, in + * fact this test is somewhat excessive since libpng doesn't make this + * decision based on colour type or bit depth! + */ + while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) + if (palette_number == 0) + { + double test_gamma = 1.0; + while (test_gamma >= .4) + { + /* There's little point testing the interlacing vs non-interlacing, + * but this can be set from the command line. + */ + gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, + test_gamma, 1/test_gamma); + test_gamma *= .95; + } + + /* And a special test for sRGB */ + gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, + .45455, 2.2); + + if (fail(pm)) + return; + } +} + +static void gamma_transform_test(png_modifier *pm, + PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, + PNG_CONST int palette_number, + PNG_CONST int interlace_type, PNG_CONST double file_gamma, + PNG_CONST double screen_gamma, PNG_CONST png_byte sbit, + PNG_CONST int use_input_precision, PNG_CONST int scale16) +{ + size_t pos = 0; + char name[64]; + + if (sbit != bit_depth && sbit != 0) + { + pos = safecat(name, sizeof name, pos, "sbit("); + pos = safecatn(name, sizeof name, pos, sbit); + pos = safecat(name, sizeof name, pos, ") "); + } + + else + pos = safecat(name, sizeof name, pos, "gamma "); + + if (scale16) + pos = safecat(name, sizeof name, pos, "16to8 "); + + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "->"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, + file_gamma, screen_gamma, sbit, 0, name, use_input_precision, + scale16, pm->test_gamma_expand16, 0 , 0, 0); +} + +static void perform_gamma_transform_tests(png_modifier *pm) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + unsigned int palette_number = 0; + + while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) + { + unsigned int i, j; + + for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j) + if (i != j) + { + gamma_transform_test(pm, colour_type, bit_depth, palette_number, + pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/, + pm->use_input_precision, 0 /*do not scale16*/); + + if (fail(pm)) + return; + } + } +} + +static void perform_gamma_sbit_tests(png_modifier *pm) +{ + png_byte sbit; + + /* The only interesting cases are colour and grayscale, alpha is ignored here + * for overall speed. Only bit depths where sbit is less than the bit depth + * are tested. + */ + for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit) + { + png_byte colour_type = 0, bit_depth = 0; + unsigned int npalette = 0; + + while (next_format(&colour_type, &bit_depth, &npalette, 1/*gamma*/)) + if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 && + ((colour_type == 3 && sbit < 8) || + (colour_type != 3 && sbit < bit_depth))) + { + unsigned int i; + + for (i=0; i<pm->ngamma_tests; ++i) + { + unsigned int j; + + for (j=0; j<pm->ngamma_tests; ++j) if (i != j) + { + gamma_transform_test(pm, colour_type, bit_depth, npalette, + pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], + sbit, pm->use_input_precision_sbit, 0 /*scale16*/); + + if (fail(pm)) + return; + } + } + } + } +} + +/* Note that this requires a 16 bit source image but produces 8 bit output, so + * we only need the 16bit write support, but the 16 bit images are only + * generated if DO_16BIT is defined. + */ +#ifdef DO_16BIT +static void perform_gamma_scale16_tests(png_modifier *pm) +{ +# ifndef PNG_MAX_GAMMA_8 +# define PNG_MAX_GAMMA_8 11 +# endif +# define SBIT_16_TO_8 PNG_MAX_GAMMA_8 + /* Include the alpha cases here. Note that sbit matches the internal value + * used by the library - otherwise we will get spurious errors from the + * internal sbit style approximation. + * + * The threshold test is here because otherwise the 16 to 8 conversion will + * proceed *without* gamma correction, and the tests above will fail (but not + * by much) - this could be fixed, it only appears with the -g option. + */ + unsigned int i, j; + for (i=0; i<pm->ngamma_tests; ++i) + { + for (j=0; j<pm->ngamma_tests; ++j) + { + if (i != j && + fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD) + { + gamma_transform_test(pm, 0, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 2, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 4, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 6, 16, 0, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, + pm->use_input_precision_16to8, 1 /*scale16*/); + + if (fail(pm)) + return; + } + } + } +} +#endif /* 16 to 8 bit conversion */ + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ + defined(PNG_READ_ALPHA_MODE_SUPPORTED) +static void gamma_composition_test(png_modifier *pm, + PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, + PNG_CONST int palette_number, + PNG_CONST int interlace_type, PNG_CONST double file_gamma, + PNG_CONST double screen_gamma, + PNG_CONST int use_input_precision, PNG_CONST int do_background, + PNG_CONST int expand_16) +{ + size_t pos = 0; + png_const_charp base; + double bg; + char name[128]; + png_color_16 background; + + /* Make up a name and get an appropriate background gamma value. */ + switch (do_background) + { + default: + base = ""; + bg = 4; /* should not be used */ + break; + case PNG_BACKGROUND_GAMMA_SCREEN: + base = " bckg(Screen):"; + bg = 1/screen_gamma; + break; + case PNG_BACKGROUND_GAMMA_FILE: + base = " bckg(File):"; + bg = file_gamma; + break; + case PNG_BACKGROUND_GAMMA_UNIQUE: + base = " bckg(Unique):"; + /* This tests the handling of a unique value, the math is such that the + * value tends to be <1, but is neither screen nor file (even if they + * match!) + */ + bg = (file_gamma + screen_gamma) / 3; + break; +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + case ALPHA_MODE_OFFSET + PNG_ALPHA_PNG: + base = " alpha(PNG)"; + bg = 4; /* should not be used */ + break; + case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: + base = " alpha(Porter-Duff)"; + bg = 4; /* should not be used */ + break; + case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: + base = " alpha(Optimized)"; + bg = 4; /* should not be used */ + break; + case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: + base = " alpha(Broken)"; + bg = 4; /* should not be used */ + break; +#endif + } + + /* Use random background values - the background is always presented in the + * output space (8 or 16 bit components). + */ + if (expand_16 || bit_depth == 16) + { + png_uint_32 r = random_32(); + + background.red = (png_uint_16)r; + background.green = (png_uint_16)(r >> 16); + r = random_32(); + background.blue = (png_uint_16)r; + background.gray = (png_uint_16)(r >> 16); + + /* In earlier libpng versions, those where DIGITIZE is set, any background + * gamma correction in the expand16 case was done using 8-bit gamma + * correction tables, resulting in larger errors. To cope with those + * cases use a 16-bit background value which will handle this gamma + * correction. + */ +# if DIGITIZE + if (expand_16 && (do_background == PNG_BACKGROUND_GAMMA_UNIQUE || + do_background == PNG_BACKGROUND_GAMMA_FILE) && + fabs(bg*screen_gamma-1) > PNG_GAMMA_THRESHOLD) + { + /* The background values will be looked up in an 8-bit table to do + * the gamma correction, so only select values which are an exact + * match for the 8-bit table entries: + */ + background.red = (png_uint_16)((background.red >> 8) * 257); + background.green = (png_uint_16)((background.green >> 8) * 257); + background.blue = (png_uint_16)((background.blue >> 8) * 257); + background.gray = (png_uint_16)((background.gray >> 8) * 257); + } +# endif + } + + else /* 8 bit colors */ + { + png_uint_32 r = random_32(); + + background.red = (png_byte)r; + background.green = (png_byte)(r >> 8); + background.blue = (png_byte)(r >> 16); + background.gray = (png_byte)(r >> 24); + } + + background.index = 193; /* rgb(193,193,193) to detect errors */ + if (!(colour_type & PNG_COLOR_MASK_COLOR)) + { + /* Grayscale input, we do not convert to RGB (TBD), so we must set the + * background to gray - else libpng seems to fail. + */ + background.red = background.green = background.blue = background.gray; + } + + pos = safecat(name, sizeof name, pos, "gamma "); + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "->"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + pos = safecat(name, sizeof name, pos, base); + if (do_background < ALPHA_MODE_OFFSET) + { + /* Include the background color and gamma in the name: */ + pos = safecat(name, sizeof name, pos, "("); + /* This assumes no expand gray->rgb - the current code won't handle that! + */ + if (colour_type & PNG_COLOR_MASK_COLOR) + { + pos = safecatn(name, sizeof name, pos, background.red); + pos = safecat(name, sizeof name, pos, ","); + pos = safecatn(name, sizeof name, pos, background.green); + pos = safecat(name, sizeof name, pos, ","); + pos = safecatn(name, sizeof name, pos, background.blue); + } + else + pos = safecatn(name, sizeof name, pos, background.gray); + pos = safecat(name, sizeof name, pos, ")^"); + pos = safecatd(name, sizeof name, pos, bg, 3); + } + + gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, + file_gamma, screen_gamma, 0/*sBIT*/, 0, name, use_input_precision, + 0/*strip 16*/, expand_16, do_background, &background, bg); +} + + +static void +perform_gamma_composition_tests(png_modifier *pm, int do_background, + int expand_16) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + unsigned int palette_number = 0; + + /* Skip the non-alpha cases - there is no setting of a transparency colour at + * present. + */ + while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) + if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0) + { + unsigned int i, j; + + /* Don't skip the i==j case here - it's relevant. */ + for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j) + { + gamma_composition_test(pm, colour_type, bit_depth, palette_number, + pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], + pm->use_input_precision, do_background, expand_16); + + if (fail(pm)) + return; + } + } +} +#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ + +static void +init_gamma_errors(png_modifier *pm) +{ + /* Use -1 to catch tests that were not actually run */ + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = -1.; + pm->error_color_8 = -1.; + pm->error_indexed = -1.; + pm->error_gray_16 = pm->error_color_16 = -1.; +} + +static void +print_one(const char *leader, double err) +{ + if (err != -1.) + printf(" %s %.5f\n", leader, err); +} + +static void +summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth, + int indexed) +{ + fflush(stderr); + + if (who) + printf("\nGamma correction with %s:\n", who); + + else + printf("\nBasic gamma correction:\n"); + + if (low_bit_depth) + { + print_one(" 2 bit gray: ", pm->error_gray_2); + print_one(" 4 bit gray: ", pm->error_gray_4); + print_one(" 8 bit gray: ", pm->error_gray_8); + print_one(" 8 bit color:", pm->error_color_8); + if (indexed) + print_one(" indexed: ", pm->error_indexed); + } + + print_one("16 bit gray: ", pm->error_gray_16); + print_one("16 bit color:", pm->error_color_16); + + fflush(stdout); +} + +static void +perform_gamma_test(png_modifier *pm, int summary) +{ + /*TODO: remove this*/ + /* Save certain values for the temporary overrides below. */ + unsigned int calculations_use_input_precision = + pm->calculations_use_input_precision; +# ifdef PNG_READ_BACKGROUND_SUPPORTED + double maxout8 = pm->maxout8; +# endif + + /* First some arbitrary no-transform tests: */ + if (!pm->this.speed && pm->test_gamma_threshold) + { + perform_gamma_threshold_tests(pm); + + if (fail(pm)) + return; + } + + /* Now some real transforms. */ + if (pm->test_gamma_transform) + { + if (summary) + { + fflush(stderr); + printf("Gamma correction error summary\n\n"); + printf("The printed value is the maximum error in the pixel values\n"); + printf("calculated by the libpng gamma correction code. The error\n"); + printf("is calculated as the difference between the output pixel\n"); + printf("value (always an integer) and the ideal value from the\n"); + printf("libpng specification (typically not an integer).\n\n"); + + printf("Expect this value to be less than .5 for 8 bit formats,\n"); + printf("less than 1 for formats with fewer than 8 bits and a small\n"); + printf("number (typically less than 5) for the 16 bit formats.\n"); + printf("For performance reasons the value for 16 bit formats\n"); + printf("increases when the image file includes an sBIT chunk.\n"); + fflush(stdout); + } + + init_gamma_errors(pm); + /*TODO: remove this. Necessary because the current libpng + * implementation works in 8 bits: + */ + if (pm->test_gamma_expand16) + pm->calculations_use_input_precision = 1; + perform_gamma_transform_tests(pm); + if (!calculations_use_input_precision) + pm->calculations_use_input_precision = 0; + + if (summary) + summarize_gamma_errors(pm, 0/*who*/, 1/*low bit depth*/, 1/*indexed*/); + + if (fail(pm)) + return; + } + + /* The sbit tests produce much larger errors: */ + if (pm->test_gamma_sbit) + { + init_gamma_errors(pm); + perform_gamma_sbit_tests(pm); + + if (summary) + summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U, 1/*indexed*/); + + if (fail(pm)) + return; + } + +#ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */ + if (pm->test_gamma_scale16) + { + /* The 16 to 8 bit strip operations: */ + init_gamma_errors(pm); + perform_gamma_scale16_tests(pm); + + if (summary) + { + fflush(stderr); + printf("\nGamma correction with 16 to 8 bit reduction:\n"); + printf(" 16 bit gray: %.5f\n", pm->error_gray_16); + printf(" 16 bit color: %.5f\n", pm->error_color_16); + fflush(stdout); + } + + if (fail(pm)) + return; + } +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if (pm->test_gamma_background) + { + init_gamma_errors(pm); + + /*TODO: remove this. Necessary because the current libpng + * implementation works in 8 bits: + */ + if (pm->test_gamma_expand16) + { + pm->calculations_use_input_precision = 1; + pm->maxout8 = .499; /* because the 16 bit background is smashed */ + } + perform_gamma_composition_tests(pm, PNG_BACKGROUND_GAMMA_UNIQUE, + pm->test_gamma_expand16); + if (!calculations_use_input_precision) + pm->calculations_use_input_precision = 0; + pm->maxout8 = maxout8; + + if (summary) + summarize_gamma_errors(pm, "background", 1, 0/*indexed*/); + + if (fail(pm)) + return; + } +#endif + +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED + if (pm->test_gamma_alpha_mode) + { + int do_background; + + init_gamma_errors(pm); + + /*TODO: remove this. Necessary because the current libpng + * implementation works in 8 bits: + */ + if (pm->test_gamma_expand16) + pm->calculations_use_input_precision = 1; + for (do_background = ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD; + do_background <= ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN && !fail(pm); + ++do_background) + perform_gamma_composition_tests(pm, do_background, + pm->test_gamma_expand16); + if (!calculations_use_input_precision) + pm->calculations_use_input_precision = 0; + + if (summary) + summarize_gamma_errors(pm, "alpha mode", 1, 0/*indexed*/); + + if (fail(pm)) + return; + } +#endif +} +#endif /* PNG_READ_GAMMA_SUPPORTED */ +#endif /* PNG_READ_SUPPORTED */ + +/* INTERLACE MACRO VALIDATION */ +/* This is copied verbatim from the specification, it is simply the pass + * number in which each pixel in each 8x8 tile appears. The array must + * be indexed adam7[y][x] and notice that the pass numbers are based at + * 1, not 0 - the base libpng uses. + */ +static PNG_CONST +png_byte adam7[8][8] = +{ + { 1,6,4,6,2,6,4,6 }, + { 7,7,7,7,7,7,7,7 }, + { 5,6,5,6,5,6,5,6 }, + { 7,7,7,7,7,7,7,7 }, + { 3,6,4,6,3,6,4,6 }, + { 7,7,7,7,7,7,7,7 }, + { 5,6,5,6,5,6,5,6 }, + { 7,7,7,7,7,7,7,7 } +}; + +/* This routine validates all the interlace support macros in png.h for + * a variety of valid PNG widths and heights. It uses a number of similarly + * named internal routines that feed off the above array. + */ +static png_uint_32 +png_pass_start_row(int pass) +{ + int x, y; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + return y; + return 0xf; +} + +static png_uint_32 +png_pass_start_col(int pass) +{ + int x, y; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + return x; + return 0xf; +} + +static int +png_pass_row_shift(int pass) +{ + int x, y, base=(-1), inc=8; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + { + if (base == (-1)) + base = y; + else if (base == y) + {} + else if (inc == y-base) + base=y; + else if (inc == 8) + inc = y-base, base=y; + else if (inc != y-base) + return 0xff; /* error - more than one 'inc' value! */ + } + + if (base == (-1)) return 0xfe; /* error - no row in pass! */ + + /* The shift is always 1, 2 or 3 - no pass has all the rows! */ + switch (inc) + { +case 2: return 1; +case 4: return 2; +case 8: return 3; +default: break; + } + + /* error - unrecognized 'inc' */ + return (inc << 8) + 0xfd; +} + +static int +png_pass_col_shift(int pass) +{ + int x, y, base=(-1), inc=8; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + { + if (base == (-1)) + base = x; + else if (base == x) + {} + else if (inc == x-base) + base=x; + else if (inc == 8) + inc = x-base, base=x; + else if (inc != x-base) + return 0xff; /* error - more than one 'inc' value! */ + } + + if (base == (-1)) return 0xfe; /* error - no row in pass! */ + + /* The shift is always 1, 2 or 3 - no pass has all the rows! */ + switch (inc) + { +case 1: return 0; /* pass 7 has all the columns */ +case 2: return 1; +case 4: return 2; +case 8: return 3; +default: break; + } + + /* error - unrecognized 'inc' */ + return (inc << 8) + 0xfd; +} + +static png_uint_32 +png_row_from_pass_row(png_uint_32 yIn, int pass) +{ + /* By examination of the array: */ + switch (pass) + { +case 0: return yIn * 8; +case 1: return yIn * 8; +case 2: return yIn * 8 + 4; +case 3: return yIn * 4; +case 4: return yIn * 4 + 2; +case 5: return yIn * 2; +case 6: return yIn * 2 + 1; +default: break; + } + + return 0xff; /* bad pass number */ +} + +static png_uint_32 +png_col_from_pass_col(png_uint_32 xIn, int pass) +{ + /* By examination of the array: */ + switch (pass) + { +case 0: return xIn * 8; +case 1: return xIn * 8 + 4; +case 2: return xIn * 4; +case 3: return xIn * 4 + 2; +case 4: return xIn * 2; +case 5: return xIn * 2 + 1; +case 6: return xIn; +default: break; + } + + return 0xff; /* bad pass number */ +} + +static int +png_row_in_interlace_pass(png_uint_32 y, int pass) +{ + /* Is row 'y' in pass 'pass'? */ + int x; + y &= 7; + ++pass; + for (x=0; x<8; ++x) if (adam7[y][x] == pass) + return 1; + + return 0; +} + +static int +png_col_in_interlace_pass(png_uint_32 x, int pass) +{ + /* Is column 'x' in pass 'pass'? */ + int y; + x &= 7; + ++pass; + for (y=0; y<8; ++y) if (adam7[y][x] == pass) + return 1; + + return 0; +} + +static png_uint_32 +png_pass_rows(png_uint_32 height, int pass) +{ + png_uint_32 tiles = height>>3; + png_uint_32 rows = 0; + unsigned int x, y; + + height &= 7; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + { + rows += tiles; + if (y < height) ++rows; + break; /* i.e. break the 'x', column, loop. */ + } + + return rows; +} + +static png_uint_32 +png_pass_cols(png_uint_32 width, int pass) +{ + png_uint_32 tiles = width>>3; + png_uint_32 cols = 0; + unsigned int x, y; + + width &= 7; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + { + cols += tiles; + if (x < width) ++cols; + break; /* i.e. break the 'y', row, loop. */ + } + + return cols; +} + +static void +perform_interlace_macro_validation(void) +{ + /* The macros to validate, first those that depend only on pass: + * + * PNG_PASS_START_ROW(pass) + * PNG_PASS_START_COL(pass) + * PNG_PASS_ROW_SHIFT(pass) + * PNG_PASS_COL_SHIFT(pass) + */ + int pass; + + for (pass=0; pass<7; ++pass) + { + png_uint_32 m, f, v; + + m = PNG_PASS_START_ROW(pass); + f = png_pass_start_row(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f); + exit(99); + } + + m = PNG_PASS_START_COL(pass); + f = png_pass_start_col(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f); + exit(99); + } + + m = PNG_PASS_ROW_SHIFT(pass); + f = png_pass_row_shift(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f); + exit(99); + } + + m = PNG_PASS_COL_SHIFT(pass); + f = png_pass_col_shift(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f); + exit(99); + } + + /* Macros that depend on the image or sub-image height too: + * + * PNG_PASS_ROWS(height, pass) + * PNG_PASS_COLS(width, pass) + * PNG_ROW_FROM_PASS_ROW(yIn, pass) + * PNG_COL_FROM_PASS_COL(xIn, pass) + * PNG_ROW_IN_INTERLACE_PASS(y, pass) + * PNG_COL_IN_INTERLACE_PASS(x, pass) + */ + for (v=0;;) + { + /* First the base 0 stuff: */ + m = PNG_ROW_FROM_PASS_ROW(v, pass); + f = png_row_from_pass_row(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(99); + } + + m = PNG_COL_FROM_PASS_COL(v, pass); + f = png_col_from_pass_col(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(99); + } + + m = PNG_ROW_IN_INTERLACE_PASS(v, pass); + f = png_row_in_interlace_pass(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(99); + } + + m = PNG_COL_IN_INTERLACE_PASS(v, pass); + f = png_col_in_interlace_pass(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(99); + } + + /* Then the base 1 stuff: */ + ++v; + m = PNG_PASS_ROWS(v, pass); + f = png_pass_rows(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(99); + } + + m = PNG_PASS_COLS(v, pass); + f = png_pass_cols(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(99); + } + + /* Move to the next v - the stepping algorithm starts skipping + * values above 1024. + */ + if (v > 1024) + { + if (v == PNG_UINT_31_MAX) + break; + + v = (v << 1) ^ v; + if (v >= PNG_UINT_31_MAX) + v = PNG_UINT_31_MAX-1; + } + } + } +} + +/* Test color encodings. These values are back-calculated from the published + * chromaticities. The values are accurate to about 14 decimal places; 15 are + * given. These values are much more accurate than the ones given in the spec, + * which typically don't exceed 4 decimal places. This allows testing of the + * libpng code to its theoretical accuracy of 4 decimal places. (If pngvalid + * used the published errors the 'slack' permitted would have to be +/-.5E-4 or + * more.) + * + * The png_modifier code assumes that encodings[0] is sRGB and treats it + * specially: do not change the first entry in this list! + */ +static PNG_CONST color_encoding test_encodings[] = +{ +/* sRGB: must be first in this list! */ +/*gamma:*/ { 1/2.2, +/*red: */ { 0.412390799265959, 0.212639005871510, 0.019330818715592 }, +/*green:*/ { 0.357584339383878, 0.715168678767756, 0.119194779794626 }, +/*blue: */ { 0.180480788401834, 0.072192315360734, 0.950532152249660} }, +/* Kodak ProPhoto (wide gamut) */ +/*gamma:*/ { 1/1.6 /*approximate: uses 1.8 power law compared to sRGB 2.4*/, +/*red: */ { 0.797760489672303, 0.288071128229293, 0.000000000000000 }, +/*green:*/ { 0.135185837175740, 0.711843217810102, 0.000000000000000 }, +/*blue: */ { 0.031349349581525, 0.000085653960605, 0.825104602510460} }, +/* Adobe RGB (1998) */ +/*gamma:*/ { 1/(2+51./256), +/*red: */ { 0.576669042910131, 0.297344975250536, 0.027031361386412 }, +/*green:*/ { 0.185558237906546, 0.627363566255466, 0.070688852535827 }, +/*blue: */ { 0.188228646234995, 0.075291458493998, 0.991337536837639} }, +/* Adobe Wide Gamut RGB */ +/*gamma:*/ { 1/(2+51./256), +/*red: */ { 0.716500716779386, 0.258728243040113, 0.000000000000000 }, +/*green:*/ { 0.101020574397477, 0.724682314948566, 0.051211818965388 }, +/*blue: */ { 0.146774385252705, 0.016589442011321, 0.773892783545073} }, +}; + +/* signal handler + * + * This attempts to trap signals and escape without crashing. It needs a + * context pointer so that it can throw an exception (call longjmp) to recover + * from the condition; this is handled by making the png_modifier used by 'main' + * into a global variable. + */ +static png_modifier pm; + +static void signal_handler(int signum) +{ + + size_t pos = 0; + char msg[64]; + + pos = safecat(msg, sizeof msg, pos, "caught signal: "); + + switch (signum) + { + case SIGABRT: + pos = safecat(msg, sizeof msg, pos, "abort"); + break; + + case SIGFPE: + pos = safecat(msg, sizeof msg, pos, "floating point exception"); + break; + + case SIGILL: + pos = safecat(msg, sizeof msg, pos, "illegal instruction"); + break; + + case SIGINT: + pos = safecat(msg, sizeof msg, pos, "interrupt"); + break; + + case SIGSEGV: + pos = safecat(msg, sizeof msg, pos, "invalid memory access"); + break; + + case SIGTERM: + pos = safecat(msg, sizeof msg, pos, "termination request"); + break; + + default: + pos = safecat(msg, sizeof msg, pos, "unknown "); + pos = safecatn(msg, sizeof msg, pos, signum); + break; + } + + store_log(&pm.this, NULL/*png_structp*/, msg, 1/*error*/); + + /* And finally throw an exception so we can keep going, unless this is + * SIGTERM in which case stop now. + */ + if (signum != SIGTERM) + { + struct exception_context *the_exception_context = + &pm.this.exception_context; + + Throw &pm.this; + } + + else + exit(1); +} + +/* main program */ +int main(int argc, char **argv) +{ + volatile int summary = 1; /* Print the error summary at the end */ + volatile int memstats = 0; /* Print memory statistics at the end */ + + /* Create the given output file on success: */ + PNG_CONST char *volatile touch = NULL; + + /* This is an array of standard gamma values (believe it or not I've seen + * every one of these mentioned somewhere.) + * + * In the following list the most useful values are first! + */ + static double + gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9}; + + /* This records the command and arguments: */ + size_t cp = 0; + char command[1024]; + + anon_context(&pm.this); + + /* Add appropriate signal handlers, just the ANSI specified ones: */ + signal(SIGABRT, signal_handler); + signal(SIGFPE, signal_handler); + signal(SIGILL, signal_handler); + signal(SIGINT, signal_handler); + signal(SIGSEGV, signal_handler); + signal(SIGTERM, signal_handler); + +#ifdef HAVE_FEENABLEEXCEPT + /* Only required to enable FP exceptions on platforms where they start off + * disabled; this is not necessary but if it is not done pngvalid will likely + * end up ignoring FP conditions that other platforms fault. + */ + feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW); +#endif + + modifier_init(&pm); + + /* Preallocate the image buffer, because we know how big it needs to be, + * note that, for testing purposes, it is deliberately mis-aligned by tag + * bytes either side. All rows have an additional five bytes of padding for + * overwrite checking. + */ + store_ensure_image(&pm.this, NULL, 2, TRANSFORM_ROWMAX, TRANSFORM_HEIGHTMAX); + + /* Don't give argv[0], it's normally some horrible libtool string: */ + cp = safecat(command, sizeof command, cp, "pngvalid"); + + /* Default to error on warning: */ + pm.this.treat_warnings_as_errors = 1; + + /* Default assume_16_bit_calculations appropriately; this tells the checking + * code that 16-bit arithmetic is used for 8-bit samples when it would make a + * difference. + */ + pm.assume_16_bit_calculations = PNG_LIBPNG_VER >= 10700; + + /* Currently 16 bit expansion happens at the end of the pipeline, so the + * calculations are done in the input bit depth not the output. + * + * TODO: fix this + */ + pm.calculations_use_input_precision = 1U; + + /* Store the test gammas */ + pm.gammas = gammas; + pm.ngammas = ARRAY_SIZE(gammas); + pm.ngamma_tests = 0; /* default to off */ + + /* And the test encodings */ + pm.encodings = test_encodings; + pm.nencodings = ARRAY_SIZE(test_encodings); + + pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */ + + /* The following allows results to pass if they correspond to anything in the + * transformed range [input-.5,input+.5]; this is is required because of the + * way libpng treates the 16_TO_8 flag when building the gamma tables in + * releases up to 1.6.0. + * + * TODO: review this + */ + pm.use_input_precision_16to8 = 1U; + pm.use_input_precision_sbit = 1U; /* because libpng now rounds sBIT */ + + /* Some default values (set the behavior for 'make check' here). + * These values simply control the maximum error permitted in the gamma + * transformations. The practial limits for human perception are described + * below (the setting for maxpc16), however for 8 bit encodings it isn't + * possible to meet the accepted capabilities of human vision - i.e. 8 bit + * images can never be good enough, regardless of encoding. + */ + pm.maxout8 = .1; /* Arithmetic error in *encoded* value */ + pm.maxabs8 = .00005; /* 1/20000 */ + pm.maxcalc8 = 1./255; /* +/-1 in 8 bits for compose errors */ + pm.maxpc8 = .499; /* I.e., .499% fractional error */ + pm.maxout16 = .499; /* Error in *encoded* value */ + pm.maxabs16 = .00005;/* 1/20000 */ + pm.maxcalc16 =1./65535;/* +/-1 in 16 bits for compose errors */ + pm.maxcalcG = 1./((1<<PNG_MAX_GAMMA_8)-1); + + /* NOTE: this is a reasonable perceptual limit. We assume that humans can + * perceive light level differences of 1% over a 100:1 range, so we need to + * maintain 1 in 10000 accuracy (in linear light space), which is what the + * following guarantees. It also allows significantly higher errors at + * higher 16 bit values, which is important for performance. The actual + * maximum 16 bit error is about +/-1.9 in the fixed point implementation but + * this is only allowed for values >38149 by the following: + */ + pm.maxpc16 = .005; /* I.e., 1/200% - 1/20000 */ + + /* Now parse the command line options. */ + while (--argc >= 1) + { + int catmore = 0; /* Set if the argument has an argument. */ + + /* Record each argument for posterity: */ + cp = safecat(command, sizeof command, cp, " "); + cp = safecat(command, sizeof command, cp, *++argv); + + if (strcmp(*argv, "-v") == 0) + pm.this.verbose = 1; + + else if (strcmp(*argv, "-l") == 0) + pm.log = 1; + + else if (strcmp(*argv, "-q") == 0) + summary = pm.this.verbose = pm.log = 0; + + else if (strcmp(*argv, "-w") == 0) + pm.this.treat_warnings_as_errors = 0; + + else if (strcmp(*argv, "--speed") == 0) + pm.this.speed = 1, pm.ngamma_tests = pm.ngammas, pm.test_standard = 0, + summary = 0; + + else if (strcmp(*argv, "--memory") == 0) + memstats = 1; + + else if (strcmp(*argv, "--size") == 0) + pm.test_size = 1; + + else if (strcmp(*argv, "--nosize") == 0) + pm.test_size = 0; + + else if (strcmp(*argv, "--standard") == 0) + pm.test_standard = 1; + + else if (strcmp(*argv, "--nostandard") == 0) + pm.test_standard = 0; + + else if (strcmp(*argv, "--transform") == 0) + pm.test_transform = 1; + + else if (strcmp(*argv, "--notransform") == 0) + pm.test_transform = 0; + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + else if (strncmp(*argv, "--transform-disable=", + sizeof "--transform-disable") == 0) + { + pm.test_transform = 1; + transform_disable(*argv + sizeof "--transform-disable"); + } + + else if (strncmp(*argv, "--transform-enable=", + sizeof "--transform-enable") == 0) + { + pm.test_transform = 1; + transform_enable(*argv + sizeof "--transform-enable"); + } +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + + else if (strcmp(*argv, "--gamma") == 0) + { + /* Just do two gamma tests here (2.2 and linear) for speed: */ + pm.ngamma_tests = 2U; + pm.test_gamma_threshold = 1; + pm.test_gamma_transform = 1; + pm.test_gamma_sbit = 1; + pm.test_gamma_scale16 = 1; + pm.test_gamma_background = 1; + pm.test_gamma_alpha_mode = 1; + } + + else if (strcmp(*argv, "--nogamma") == 0) + pm.ngamma_tests = 0; + + else if (strcmp(*argv, "--gamma-threshold") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_threshold = 1; + + else if (strcmp(*argv, "--nogamma-threshold") == 0) + pm.test_gamma_threshold = 0; + + else if (strcmp(*argv, "--gamma-transform") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_transform = 1; + + else if (strcmp(*argv, "--nogamma-transform") == 0) + pm.test_gamma_transform = 0; + + else if (strcmp(*argv, "--gamma-sbit") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_sbit = 1; + + else if (strcmp(*argv, "--nogamma-sbit") == 0) + pm.test_gamma_sbit = 0; + + else if (strcmp(*argv, "--gamma-16-to-8") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_scale16 = 1; + + else if (strcmp(*argv, "--nogamma-16-to-8") == 0) + pm.test_gamma_scale16 = 0; + + else if (strcmp(*argv, "--gamma-background") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_background = 1; + + else if (strcmp(*argv, "--nogamma-background") == 0) + pm.test_gamma_background = 0; + + else if (strcmp(*argv, "--gamma-alpha-mode") == 0) + pm.ngamma_tests = 2U, pm.test_gamma_alpha_mode = 1; + + else if (strcmp(*argv, "--nogamma-alpha-mode") == 0) + pm.test_gamma_alpha_mode = 0; + + else if (strcmp(*argv, "--expand16") == 0) + pm.test_gamma_expand16 = 1; + + else if (strcmp(*argv, "--noexpand16") == 0) + pm.test_gamma_expand16 = 0; + + else if (strcmp(*argv, "--more-gammas") == 0) + pm.ngamma_tests = 3U; + + else if (strcmp(*argv, "--all-gammas") == 0) + pm.ngamma_tests = pm.ngammas; + + else if (strcmp(*argv, "--progressive-read") == 0) + pm.this.progressive = 1; + + else if (strcmp(*argv, "--use-update-info") == 0) + ++pm.use_update_info; /* Can call multiple times */ + + else if (strcmp(*argv, "--interlace") == 0) + { +# ifdef PNG_WRITE_INTERLACING_SUPPORTED + pm.interlace_type = PNG_INTERLACE_ADAM7; +# else + fprintf(stderr, "pngvalid: no write interlace support\n"); + return SKIP; +# endif + } + + else if (strcmp(*argv, "--use-input-precision") == 0) + pm.use_input_precision = 1U; + + else if (strcmp(*argv, "--use-calculation-precision") == 0) + pm.use_input_precision = 0; + + else if (strcmp(*argv, "--calculations-use-input-precision") == 0) + pm.calculations_use_input_precision = 1U; + + else if (strcmp(*argv, "--assume-16-bit-calculations") == 0) + pm.assume_16_bit_calculations = 1U; + + else if (strcmp(*argv, "--calculations-follow-bit-depth") == 0) + pm.calculations_use_input_precision = + pm.assume_16_bit_calculations = 0; + + else if (strcmp(*argv, "--exhaustive") == 0) + pm.test_exhaustive = 1; + + else if (argc > 1 && strcmp(*argv, "--sbitlow") == 0) + --argc, pm.sbitlow = (png_byte)atoi(*++argv), catmore = 1; + + else if (argc > 1 && strcmp(*argv, "--touch") == 0) + --argc, touch = *++argv, catmore = 1; + + else if (argc > 1 && strncmp(*argv, "--max", 5) == 0) + { + --argc; + + if (strcmp(5+*argv, "abs8") == 0) + pm.maxabs8 = atof(*++argv); + + else if (strcmp(5+*argv, "abs16") == 0) + pm.maxabs16 = atof(*++argv); + + else if (strcmp(5+*argv, "calc8") == 0) + pm.maxcalc8 = atof(*++argv); + + else if (strcmp(5+*argv, "calc16") == 0) + pm.maxcalc16 = atof(*++argv); + + else if (strcmp(5+*argv, "out8") == 0) + pm.maxout8 = atof(*++argv); + + else if (strcmp(5+*argv, "out16") == 0) + pm.maxout16 = atof(*++argv); + + else if (strcmp(5+*argv, "pc8") == 0) + pm.maxpc8 = atof(*++argv); + + else if (strcmp(5+*argv, "pc16") == 0) + pm.maxpc16 = atof(*++argv); + + else + { + fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv); + exit(99); + } + + catmore = 1; + } + + else if (strcmp(*argv, "--log8") == 0) + --argc, pm.log8 = atof(*++argv), catmore = 1; + + else if (strcmp(*argv, "--log16") == 0) + --argc, pm.log16 = atof(*++argv), catmore = 1; + +#ifdef PNG_SET_OPTION_SUPPORTED + else if (strncmp(*argv, "--option=", 9) == 0) + { + /* Syntax of the argument is <option>:{on|off} */ + const char *arg = 9+*argv; + unsigned char option=0, setting=0; + +#ifdef PNG_ARM_NEON_API_SUPPORTED + if (strncmp(arg, "arm-neon:", 9) == 0) + option = PNG_ARM_NEON, arg += 9; + + else +#endif +#ifdef PNG_MAXIMUM_INFLATE_WINDOW + if (strncmp(arg, "max-inflate-window:", 19) == 0) + option = PNG_MAXIMUM_INFLATE_WINDOW, arg += 19; + + else +#endif + { + fprintf(stderr, "pngvalid: %s: %s: unknown option\n", *argv, arg); + exit(99); + } + + if (strcmp(arg, "off") == 0) + setting = PNG_OPTION_OFF; + + else if (strcmp(arg, "on") == 0) + setting = PNG_OPTION_ON; + + else + { + fprintf(stderr, + "pngvalid: %s: %s: unknown setting (use 'on' or 'off')\n", + *argv, arg); + exit(99); + } + + pm.this.options[pm.this.noptions].option = option; + pm.this.options[pm.this.noptions++].setting = setting; + } +#endif /* PNG_SET_OPTION_SUPPORTED */ + + else + { + fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv); + exit(99); + } + + if (catmore) /* consumed an extra *argv */ + { + cp = safecat(command, sizeof command, cp, " "); + cp = safecat(command, sizeof command, cp, *argv); + } + } + + /* If pngvalid is run with no arguments default to a reasonable set of the + * tests. + */ + if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 && + pm.ngamma_tests == 0) + { + /* Make this do all the tests done in the test shell scripts with the same + * parameters, where possible. The limitation is that all the progressive + * read and interlace stuff has to be done in separate runs, so only the + * basic 'standard' and 'size' tests are done. + */ + pm.test_standard = 1; + pm.test_size = 1; + pm.test_transform = 1; + pm.ngamma_tests = 2U; + } + + if (pm.ngamma_tests > 0 && + pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 && + pm.test_gamma_sbit == 0 && pm.test_gamma_scale16 == 0 && + pm.test_gamma_background == 0 && pm.test_gamma_alpha_mode == 0) + { + pm.test_gamma_threshold = 1; + pm.test_gamma_transform = 1; + pm.test_gamma_sbit = 1; + pm.test_gamma_scale16 = 1; + pm.test_gamma_background = 1; + pm.test_gamma_alpha_mode = 1; + } + + else if (pm.ngamma_tests == 0) + { + /* Nothing to test so turn everything off: */ + pm.test_gamma_threshold = 0; + pm.test_gamma_transform = 0; + pm.test_gamma_sbit = 0; + pm.test_gamma_scale16 = 0; + pm.test_gamma_background = 0; + pm.test_gamma_alpha_mode = 0; + } + + Try + { + /* Make useful base images */ + make_transform_images(&pm.this); + + /* Perform the standard and gamma tests. */ + if (pm.test_standard) + { + perform_interlace_macro_validation(); + perform_formatting_test(&pm.this); +# ifdef PNG_READ_SUPPORTED + perform_standard_test(&pm); +# endif + perform_error_test(&pm); + } + + /* Various oddly sized images: */ + if (pm.test_size) + { + make_size_images(&pm.this); +# ifdef PNG_READ_SUPPORTED + perform_size_test(&pm); +# endif + } + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED + /* Combinatorial transforms: */ + if (pm.test_transform) + perform_transform_test(&pm); +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +#ifdef PNG_READ_GAMMA_SUPPORTED + if (pm.ngamma_tests > 0) + perform_gamma_test(&pm, summary); +#endif + } + + Catch_anonymous + { + fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n"); + if (!pm.this.verbose) + { + if (pm.this.error[0] != 0) + fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error); + + fprintf(stderr, "pngvalid: run with -v to see what happened\n"); + } + exit(1); + } + + if (summary) + { + printf("%s: %s (%s point arithmetic)\n", + (pm.this.nerrors || (pm.this.treat_warnings_as_errors && + pm.this.nwarnings)) ? "FAIL" : "PASS", + command, +#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500 + "floating" +#else + "fixed" +#endif + ); + } + + if (memstats) + { + printf("Allocated memory statistics (in bytes):\n" + "\tread %lu maximum single, %lu peak, %lu total\n" + "\twrite %lu maximum single, %lu peak, %lu total\n", + (unsigned long)pm.this.read_memory_pool.max_max, + (unsigned long)pm.this.read_memory_pool.max_limit, + (unsigned long)pm.this.read_memory_pool.max_total, + (unsigned long)pm.this.write_memory_pool.max_max, + (unsigned long)pm.this.write_memory_pool.max_limit, + (unsigned long)pm.this.write_memory_pool.max_total); + } + + /* Do this here to provoke memory corruption errors in memory not directly + * allocated by libpng - not a complete test, but better than nothing. + */ + store_delete(&pm.this); + + /* Error exit if there are any errors, and maybe if there are any + * warnings. + */ + if (pm.this.nerrors || (pm.this.treat_warnings_as_errors && + pm.this.nwarnings)) + { + if (!pm.this.verbose) + fprintf(stderr, "pngvalid: %s\n", pm.this.error); + + fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors, + pm.this.nwarnings); + + exit(1); + } + + /* Success case. */ + if (touch != NULL) + { + FILE *fsuccess = fopen(touch, "wt"); + + if (fsuccess != NULL) + { + int error = 0; + fprintf(fsuccess, "PNG validation succeeded\n"); + fflush(fsuccess); + error = ferror(fsuccess); + + if (fclose(fsuccess) || error) + { + fprintf(stderr, "%s: write failed\n", touch); + exit(1); + } + } + + else + { + fprintf(stderr, "%s: open failed\n", touch); + exit(1); + } + } + + /* This is required because some very minimal configurations do not use it: + */ + UNUSED(fail) + return 0; +} +#else /* write or low level APIs not supported */ +int main(void) +{ + fprintf(stderr, + "pngvalid: no low level write support in libpng, all tests skipped\n"); + /* So the test is skipped: */ + return SKIP; +} +#endif diff --git a/libpng/contrib/libtests/readpng.c b/libpng/contrib/libtests/readpng.c new file mode 100644 index 000000000..7ba46d0b9 --- /dev/null +++ b/libpng/contrib/libtests/readpng.c @@ -0,0 +1,104 @@ +/* readpng.c + * + * Copyright (c) 2013 John Cunningham Bowler + * + * Last changed in libpng 1.6.1 [March 28, 2013] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Load an arbitrary number of PNG files (from the command line, or, if there + * are no arguments on the command line, from stdin) then run a time test by + * reading each file by row. The test does nothing with the read result and + * does no transforms. The only output is a time as a floating point number of + * seconds with 9 decimal digits. + */ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +static int +read_png(FILE *fp) +{ + png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0); + png_infop info_ptr = NULL; + png_bytep row = NULL, display = NULL; + + if (png_ptr == NULL) + return 0; + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + if (row != NULL) free(row); + if (display != NULL) free(display); + return 0; + } + + png_init_io(png_ptr, fp); + + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + png_error(png_ptr, "OOM allocating info structure"); + + png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS, NULL, 0); + + png_read_info(png_ptr, info_ptr); + + { + png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + row = malloc(rowbytes); + display = malloc(rowbytes); + + if (row == NULL || display == NULL) + png_error(png_ptr, "OOM allocating row buffers"); + + { + png_uint_32 height = png_get_image_height(png_ptr, info_ptr); + int passes = png_set_interlace_handling(png_ptr); + int pass; + + png_start_read_image(png_ptr); + + for (pass = 0; pass < passes; ++pass) + { + png_uint_32 y = height; + + /* NOTE: this trashes the row each time; interlace handling won't + * work, but this avoids memory thrashing for speed testing. + */ + while (y-- > 0) + png_read_row(png_ptr, row, display); + } + } + } + + /* Make sure to read to the end of the file: */ + png_read_end(png_ptr, info_ptr); + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + free(row); + free(display); + return 1; +} + +int +main(void) +{ + /* Exit code 0 on success. */ + return !read_png(stdin); +} diff --git a/libpng/contrib/libtests/tarith.c b/libpng/contrib/libtests/tarith.c new file mode 100644 index 000000000..cdb00dbf7 --- /dev/null +++ b/libpng/contrib/libtests/tarith.c @@ -0,0 +1,999 @@ + +/* tarith.c + * + * Copyright (c) 2011-2013 John Cunningham Bowler + * + * Last changed in libpng 1.6.0 [February 14, 2013] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Test internal arithmetic functions of libpng. + * + * This code must be linked against a math library (-lm), but does not require + * libpng or zlib to work. Because it includes the complete source of 'png.c' + * it tests the code with whatever compiler options are used to build it. + * Changing these options can substantially change the errors in the + * calculations that the compiler chooses! + */ +#define _POSIX_SOURCE 1 +#define _ISOC99_SOURCE 1 + +/* Obtain a copy of the code to be tested (plus other things), disabling + * stuff that is not required. + */ +#include <math.h> +#include <stdlib.h> +#include <ctype.h> +#include <string.h> +#include <assert.h> + +#include "../../pngpriv.h" + +#define png_error png_warning + +void png_warning(png_const_structrp png_ptr, png_const_charp msg) +{ + fprintf(stderr, "validation: %s\n", msg); +} + +#define png_fixed_error png_fixed_warning + +void png_fixed_warning(png_const_structrp png_ptr, png_const_charp msg) +{ + fprintf(stderr, "overflow in: %s\n", msg); +} + +#define png_set_error_fn(pp, ep, efp, wfp) ((void)0) +#define png_malloc(pp, s) malloc(s) +#define png_malloc_warn(pp, s) malloc(s) +#define png_malloc_base(pp, s) malloc(s) +#define png_calloc(pp, s) calloc(1, (s)) +#define png_free(pp, s) free(s) + +#define png_safecat(b, sb, pos, str) (pos) +#define png_format_number(start, end, format, number) (start) + +#define crc32(crc, pp, s) (crc) +#define inflateReset(zs) Z_OK + +#define png_create_struct(type) (0) +#define png_destroy_struct(pp) ((void)0) +#define png_create_struct_2(type, m, mm) (0) +#define png_destroy_struct_2(pp, f, mm) ((void)0) + +#undef PNG_SIMPLIFIED_READ_SUPPORTED +#undef PNG_SIMPLIFIED_WRITE_SUPPORTED +#undef PNG_USER_MEM_SUPPORTED + +#include "../../png.c" + +/* Validate ASCII to fp routines. */ +static int verbose = 0; + +int validation_ascii_to_fp(int count, int argc, char **argv) +{ + int showall = 0; + double max_error=2; /* As a percentage error-in-last-digit/.5 */ + double max_error_abs=17; /* Used when precision is DBL_DIG */ + double max = 0; + double max_abs = 0; + double test = 0; /* Important to test this. */ + int precision = 5; + int nonfinite = 0; + int finite = 0; + int ok = 0; + int failcount = 0; + int minorarith = 0; + + while (--argc > 0) + if (strcmp(*++argv, "-a") == 0) + showall = 1; + else if (strcmp(*argv, "-e") == 0 && argc > 0) + { + --argc; + max_error = atof(*++argv); + } + else if (strcmp(*argv, "-E") == 0 && argc > 0) + { + --argc; + max_error_abs = atof(*++argv); + } + else + { + fprintf(stderr, "unknown argument %s\n", *argv); + return 1; + } + + do + { + png_size_t index; + int state, failed = 0; + char buffer[64]; + + if (isfinite(test)) + ++finite; + else + ++nonfinite; + + if (verbose) + fprintf(stderr, "%.*g %d\n", DBL_DIG, test, precision); + + /* Check for overflow in the buffer by setting a marker. */ + memset(buffer, 71, sizeof buffer); + + png_ascii_from_fp(0, buffer, precision+10, test, precision); + + /* Allow for a three digit exponent, this stuff will fail if + * the exponent is bigger than this! + */ + if (buffer[precision+7] != 71) + { + fprintf(stderr, "%g[%d] -> '%s'[%lu] buffer overflow\n", test, + precision, buffer, (unsigned long)strlen(buffer)); + failed = 1; + } + + /* Following are used for the number parser below and must be + * initialized to zero. + */ + state = 0; + index = 0; + if (!isfinite(test)) + { + /* Expect 'inf' */ + if (test >= 0 && strcmp(buffer, "inf") || + test < 0 && strcmp(buffer, "-inf")) + { + fprintf(stderr, "%g[%d] -> '%s' but expected 'inf'\n", test, + precision, buffer); + failed = 1; + } + } + else if (!png_check_fp_number(buffer, precision+10, &state, &index) || + buffer[index] != 0) + { + fprintf(stderr, "%g[%d] -> '%s' but has bad format ('%c')\n", test, + precision, buffer, buffer[index]); + failed = 1; + } + else if (PNG_FP_IS_NEGATIVE(state) && !(test < 0)) + { + fprintf(stderr, "%g[%d] -> '%s' but negative value not so reported\n", + test, precision, buffer); + failed = 1; + assert(!PNG_FP_IS_ZERO(state)); + assert(!PNG_FP_IS_POSITIVE(state)); + } + else if (PNG_FP_IS_ZERO(state) && !(test == 0)) + { + fprintf(stderr, "%g[%d] -> '%s' but zero value not so reported\n", + test, precision, buffer); + failed = 1; + assert(!PNG_FP_IS_NEGATIVE(state)); + assert(!PNG_FP_IS_POSITIVE(state)); + } + else if (PNG_FP_IS_POSITIVE(state) && !(test > 0)) + { + fprintf(stderr, "%g[%d] -> '%s' but postive value not so reported\n", + test, precision, buffer); + failed = 1; + assert(!PNG_FP_IS_NEGATIVE(state)); + assert(!PNG_FP_IS_ZERO(state)); + } + else + { + /* Check the result against the original. */ + double out = atof(buffer); + double change = fabs((out - test)/test); + double allow = .5/pow(10, + (precision >= DBL_DIG) ? DBL_DIG-1 : precision-1); + + /* NOTE: if you hit this error case are you compiling with gcc + * and -O0? Try -O2 - the errors can accumulate if the FP + * code above is not optimized and may drift outside the .5 in + * DBL_DIG allowed. In any case a small number of errors may + * occur (very small ones - 1 or 2%) because of rounding in the + * calculations, either in the conversion API or in atof. + */ + if (change >= allow && (isfinite(out) || + fabs(test/DBL_MAX) <= 1-allow)) + { + double percent = (precision >= DBL_DIG) ? max_error_abs : max_error; + double allowp = (change-allow)*100/allow; + + if (precision >= DBL_DIG) + { + if (max_abs < allowp) max_abs = allowp; + } + + else + { + if (max < allowp) max = allowp; + } + + if (showall || allowp >= percent) + { + fprintf(stderr, + "%.*g[%d] -> '%s' -> %.*g number changed (%g > %g (%d%%))\n", + DBL_DIG, test, precision, buffer, DBL_DIG, out, change, allow, + (int)round(allowp)); + failed = 1; + } + else + ++minorarith; + } + } + + if (failed) + ++failcount; + else + ++ok; + +skip: + /* Generate a new number and precision. */ + precision = rand(); + if (precision & 1) test = -test; + precision >>= 1; + + /* Generate random numbers. */ + if (test == 0 || !isfinite(test)) + test = precision+1; + else + { + /* Derive the exponent from the previous rand() value. */ + int exponent = precision % (DBL_MAX_EXP - DBL_MIN_EXP) + DBL_MIN_EXP; + int tmp; + test = frexp(test * rand(), &tmp); + test = ldexp(test, exponent); + precision >>= 8; /* arbitrary */ + } + + /* This limits the precision to 32 digits, enough for standard + * IEEE implementations which have at most 15 digits. + */ + precision = (precision & 0x1f) + 1; + } + while (--count); + + printf("Tested %d finite values, %d non-finite, %d OK (%d failed) %d minor " + "arithmetic errors\n", finite, nonfinite, ok, failcount, minorarith); + printf(" Error with >=%d digit precision %.2f%%\n", DBL_DIG, max_abs); + printf(" Error with < %d digit precision %.2f%%\n", DBL_DIG, max); + + return 0; +} + +/* Observe that valid FP numbers have the forms listed in the PNG extensions + * specification: + * + * [+,-]{integer,integer.fraction,.fraction}[{e,E}[+,-]integer] + * + * Test each of these in turn, including invalid cases. + */ +typedef enum checkfp_state +{ + start, fraction, exponent, states +} checkfp_state; + +/* The characters (other than digits) that characterize the states: */ +static const char none[] = ""; +static const char hexdigits[16] = "0123456789ABCDEF"; + +static const struct +{ + const char *start; /* Characters valid at the start */ + const char *end; /* Valid characters that end the state */ + const char *tests; /* Characters to test after 2 digits seen */ +} +state_characters[states] = +{ + /* start: */ { "+-.", ".eE", "+-.e*0369" }, + /* fraction: */ { none, "eE", "+-.E#0147" }, + /* exponent: */ { "+-", none, "+-.eE^0258" } +}; + +typedef struct +{ + char number[1024]; /* Buffer for number being tested */ + int limit; /* Command line limit */ + int verbose; /* Shadows global variable */ + int ctimes; /* Number of numbers tested */ + int cmillions; /* Count of millions of numbers */ + int cinvalid; /* Invalid strings checked */ + int cnoaccept; /* Characters not accepted */ +} +checkfp_command; + +typedef struct +{ + int cnumber; /* Index into number string */ + checkfp_state check_state; /* Current number state */ + int at_start; /* At start (first character) of state */ + int cdigits_in_state; /* Digits seen in that state */ + int limit; /* Limit on same for checking all chars */ + int state; /* Current parser state */ + int is_negative; /* Number is negative */ + int is_zero; /* Number is (still) zero */ + int number_was_valid; /* Previous character validity */ +} +checkfp_control; + +static int check_all_characters(checkfp_command *co, checkfp_control c); + +static int check_some_characters(checkfp_command *co, checkfp_control c, + const char *tests); + +static int check_one_character(checkfp_command *co, checkfp_control c, int ch) +{ + /* Test this character (ch) to ensure the parser does the correct thing. + */ + png_size_t index = 0; + const char test = (char)ch; + const int number_is_valid = png_check_fp_number(&test, 1, &c.state, &index); + const int character_accepted = (index == 1); + + if (c.check_state != exponent && isdigit(ch) && ch != '0') + c.is_zero = 0; + + if (c.check_state == start && c.at_start && ch == '-') + c.is_negative = 1; + + if (isprint(ch)) + co->number[c.cnumber++] = (char)ch; + else + { + co->number[c.cnumber++] = '<'; + co->number[c.cnumber++] = hexdigits[(ch >> 4) & 0xf]; + co->number[c.cnumber++] = hexdigits[ch & 0xf]; + co->number[c.cnumber++] = '>'; + } + co->number[c.cnumber] = 0; + + if (co->verbose > 1) + fprintf(stderr, "%s\n", co->number); + + if (++(co->ctimes) == 1000000) + { + if (co->verbose == 1) + fputc('.', stderr); + co->ctimes = 0; + ++(co->cmillions); + } + + if (!number_is_valid) + ++(co->cinvalid); + + if (!character_accepted) + ++(co->cnoaccept); + + /* This should never fail (it's a serious bug if it does): */ + if (index != 0 && index != 1) + { + fprintf(stderr, "%s: read beyond end of string (%lu)\n", co->number, + (unsigned long)index); + return 0; + } + + /* Validate the new state, note that the PNG_FP_IS_ macros all return + * false unless the number is valid. + */ + if (PNG_FP_IS_NEGATIVE(c.state) != + (number_is_valid && !c.is_zero && c.is_negative)) + { + fprintf(stderr, "%s: negative when it is not\n", co->number); + return 0; + } + + if (PNG_FP_IS_ZERO(c.state) != (number_is_valid && c.is_zero)) + { + fprintf(stderr, "%s: zero when it is not\n", co->number); + return 0; + } + + if (PNG_FP_IS_POSITIVE(c.state) != + (number_is_valid && !c.is_zero && !c.is_negative)) + { + fprintf(stderr, "%s: positive when it is not\n", co->number); + return 0; + } + + /* Testing a digit */ + if (isdigit(ch)) + { + if (!character_accepted) + { + fprintf(stderr, "%s: digit '%c' not accepted\n", co->number, ch); + return 0; + } + + if (!number_is_valid) + { + fprintf(stderr, "%s: saw a digit (%c) but number not valid\n", + co->number, ch); + return 0; + } + + ++c.cdigits_in_state; + c.at_start = 0; + c.number_was_valid = 1; + + /* Continue testing characters in this state. Either test all of + * them or, if we have already seen one digit in this state, just test a + * limited set. + */ + if (c.cdigits_in_state < 1) + return check_all_characters(co, c); + + else + return check_some_characters(co, c, + state_characters[c.check_state].tests); + } + + /* A non-digit; is it allowed here? */ + else if (((ch == '+' || ch == '-') && c.check_state != fraction && + c.at_start) || + (ch == '.' && c.check_state == start) || + ((ch == 'e' || ch == 'E') && c.number_was_valid && + c.check_state != exponent)) + { + if (!character_accepted) + { + fprintf(stderr, "%s: character '%c' not accepted\n", co->number, ch); + return 0; + } + + /* The number remains valid after start of fraction but nowhere else. */ + if (number_is_valid && (c.check_state != start || ch != '.')) + { + fprintf(stderr, "%s: saw a non-digit (%c) but number valid\n", + co->number, ch); + return 0; + } + + c.number_was_valid = number_is_valid; + + /* Check for a state change. When changing to 'fraction' if the number + * is valid at this point set the at_start to false to allow an exponent + * 'e' to come next. + */ + if (c.check_state == start && ch == '.') + { + c.check_state = fraction; + c.at_start = !number_is_valid; + c.cdigits_in_state = 0; + c.limit = co->limit; + return check_all_characters(co, c); + } + + else if (c.check_state < exponent && (ch == 'e' || ch == 'E')) + { + c.check_state = exponent; + c.at_start = 1; + c.cdigits_in_state = 0; + c.limit = co->limit; + return check_all_characters(co, c); + } + + /* Else it was a sign, and the state doesn't change. */ + else + { + if (ch != '-' && ch != '+') + { + fprintf(stderr, "checkfp: internal error (1)\n"); + return 0; + } + + c.at_start = 0; + return check_all_characters(co, c); + } + } + + /* Testing an invalid character */ + else + { + if (character_accepted) + { + fprintf(stderr, "%s: character '%c' [0x%.2x] accepted\n", co->number, + ch, ch); + return 0; + } + + if (number_is_valid != c.number_was_valid) + { + fprintf(stderr, + "%s: character '%c' [0x%.2x] changed number validity\n", co->number, + ch, ch); + return 0; + } + + /* Do nothing - the parser has stuck; return success and keep going with + * the next character. + */ + } + + /* Successful return (the caller will try the next character.) */ + return 1; +} + +static int check_all_characters(checkfp_command *co, checkfp_control c) +{ + int ch; + + if (c.cnumber+4 < sizeof co->number) for (ch=0; ch<256; ++ch) + { + if (!check_one_character(co, c, ch)) + return 0; + } + + return 1; +} + +static int check_some_characters(checkfp_command *co, checkfp_control c, + const char *tests) +{ + int i; + + --(c.limit); + + if (c.cnumber+4 < sizeof co->number && c.limit >= 0) + { + if (c.limit > 0) for (i=0; tests[i]; ++i) + { + if (!check_one_character(co, c, tests[i])) + return 0; + } + + /* At the end check all the characters. */ + else + return check_all_characters(co, c); + } + + return 1; +} + +int validation_checkfp(int count, int argc, char **argv) +{ + int result; + checkfp_command command; + checkfp_control control; + + command.number[0] = 0; + command.limit = 3; + command.verbose = verbose; + command.ctimes = 0; + command.cmillions = 0; + command.cinvalid = 0; + command.cnoaccept = 0; + + while (--argc > 0) + { + ++argv; + if (argc > 1 && strcmp(*argv, "-l") == 0) + { + --argc; + command.limit = atoi(*++argv); + } + + else + { + fprintf(stderr, "unknown argument %s\n", *argv); + return 1; + } + } + + control.cnumber = 0; + control.check_state = start; + control.at_start = 1; + control.cdigits_in_state = 0; + control.limit = command.limit; + control.state = 0; + control.is_negative = 0; + control.is_zero = 1; + control.number_was_valid = 0; + + result = check_all_characters(&command, control); + + printf("checkfp: %s: checked %d,%.3d,%.3d,%.3d strings (%d invalid)\n", + result ? "pass" : "FAIL", command.cmillions / 1000, + command.cmillions % 1000, command.ctimes / 1000, command.ctimes % 1000, + command.cinvalid); + + return result; +} + +int validation_muldiv(int count, int argc, char **argv) +{ + int tested = 0; + int overflow = 0; + int error = 0; + int error64 = 0; + int passed = 0; + int randbits = 0; + png_uint_32 randbuffer; + png_fixed_point a; + png_int_32 times, div; + + while (--argc > 0) + { + fprintf(stderr, "unknown argument %s\n", *++argv); + return 1; + } + + /* Find out about the random number generator. */ + randbuffer = RAND_MAX; + while (randbuffer != 0) ++randbits, randbuffer >>= 1; + printf("Using random number generator that makes %d bits\n", randbits); + for (div=0; div<32; div += randbits) + randbuffer = (randbuffer << randbits) ^ rand(); + + a = 0; + times = div = 0; + do + { + png_fixed_point result; + /* NOTE: your mileage may vary, a type is required below that can + * hold 64 bits or more, if floating point is used a 64 bit or + * better mantissa is required. + */ + long long int fp, fpround; + unsigned long hi, lo; + int ok; + + /* Check the values, png_64bit_product can only handle positive + * numbers, so correct for that here. + */ + { + long u1, u2; + int n = 0; + if (a < 0) u1 = -a, n = 1; else u1 = a; + if (times < 0) u2 = -times, n = !n; else u2 = times; + png_64bit_product(u1, u2, &hi, &lo); + if (n) + { + /* -x = ~x+1 */ + lo = ((~lo) + 1) & 0xffffffff; + hi = ~hi; + if (lo == 0) ++hi; + } + } + + fp = a; + fp *= times; + if ((fp & 0xffffffff) != lo || ((fp >> 32) & 0xffffffff) != hi) + { + fprintf(stderr, "png_64bit_product %d * %d -> %lx|%.8lx not %llx\n", + a, times, hi, lo, fp); + ++error64; + } + + if (div != 0) + { + /* Round - this is C round to zero. */ + if ((fp < 0) != (div < 0)) + fp -= div/2; + else + fp += div/2; + + fp /= div; + fpround = fp; + /* Assume 2's complement here: */ + ok = fpround <= PNG_UINT_31_MAX && + fpround >= -1-(long long int)PNG_UINT_31_MAX; + if (!ok) ++overflow; + } + else + ok = 0, ++overflow, fpround = fp/*misleading*/; + + if (verbose) + fprintf(stderr, "TEST %d * %d / %d -> %lld (%s)\n", a, times, div, + fp, ok ? "ok" : "overflow"); + + ++tested; + if (png_muldiv(&result, a, times, div) != ok) + { + ++error; + if (ok) + fprintf(stderr, "%d * %d / %d -> overflow (expected %lld)\n", a, + times, div, fp); + else + fprintf(stderr, "%d * %d / %d -> %d (expected overflow %lld)\n", a, + times, div, result, fp); + } + else if (ok && result != fpround) + { + ++error; + fprintf(stderr, "%d * %d / %d -> %d not %lld\n", a, times, div, result, + fp); + } + else + ++passed; + + /* Generate three new values, this uses rand() and rand() only returns + * up to RAND_MAX. + */ + /* CRUDE */ + a += times; + times += div; + div = randbuffer; + randbuffer = (randbuffer << randbits) ^ rand(); + } + while (--count > 0); + + printf("%d tests including %d overflows, %d passed, %d failed (%d 64 bit " + "errors)\n", tested, overflow, passed, error, error64); + return 0; +} + +/* When FP is on this just becomes a speed test - compile without FP to get real + * validation. + */ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED +#define LN2 .000010576586617430806112933839 /* log(2)/65536 */ +#define L2INV 94548.46219969910586572651 /* 65536/log(2) */ + +/* For speed testing, need the internal functions too: */ +static png_uint_32 png_log8bit(unsigned x) +{ + if (x > 0) + return (png_uint_32)floor(.5-log(x/255.)*L2INV); + + return 0xffffffff; +} + +static png_uint_32 png_log16bit(png_uint_32 x) +{ + if (x > 0) + return (png_uint_32)floor(.5-log(x/65535.)*L2INV); + + return 0xffffffff; +} + +static png_uint_32 png_exp(png_uint_32 x) +{ + return (png_uint_32)floor(.5 + exp(x * -LN2) * 0xffffffffU); +} + +static png_byte png_exp8bit(png_uint_32 log) +{ + return (png_byte)floor(.5 + exp(log * -LN2) * 255); +} + +static png_uint_16 png_exp16bit(png_uint_32 log) +{ + return (png_uint_16)floor(.5 + exp(log * -LN2) * 65535); +} +#endif /* FLOATING_ARITHMETIC */ + +int validation_gamma(int argc, char **argv) +{ + double gamma[9] = { 2.2, 1.8, 1.52, 1.45, 1., 1/1.45, 1/1.52, 1/1.8, 1/2.2 }; + double maxerr; + int i, silent=0, onlygamma=0; + + /* Silence the output with -s, just test the gamma functions with -g: */ + while (--argc > 0) + if (strcmp(*++argv, "-s") == 0) + silent = 1; + else if (strcmp(*argv, "-g") == 0) + onlygamma = 1; + else + { + fprintf(stderr, "unknown argument %s\n", *argv); + return 1; + } + + if (!onlygamma) + { + /* First validate the log functions: */ + maxerr = 0; + for (i=0; i<256; ++i) + { + double correct = -log(i/255.)/log(2.)*65536; + double error = png_log8bit(i) - correct; + + if (i != 0 && fabs(error) > maxerr) + maxerr = fabs(error); + + if (i == 0 && png_log8bit(i) != 0xffffffff || + i != 0 && png_log8bit(i) != floor(correct+.5)) + { + fprintf(stderr, "8 bit log error: %d: got %u, expected %f\n", + i, png_log8bit(i), correct); + } + } + + if (!silent) + printf("maximum 8 bit log error = %f\n", maxerr); + + maxerr = 0; + for (i=0; i<65536; ++i) + { + double correct = -log(i/65535.)/log(2.)*65536; + double error = png_log16bit(i) - correct; + + if (i != 0 && fabs(error) > maxerr) + maxerr = fabs(error); + + if (i == 0 && png_log16bit(i) != 0xffffffff || + i != 0 && png_log16bit(i) != floor(correct+.5)) + { + if (error > .68) /* By experiment error is less than .68 */ + { + fprintf(stderr, "16 bit log error: %d: got %u, expected %f" + " error: %f\n", i, png_log16bit(i), correct, error); + } + } + } + + if (!silent) + printf("maximum 16 bit log error = %f\n", maxerr); + + /* Now exponentiations. */ + maxerr = 0; + for (i=0; i<=0xfffff; ++i) + { + double correct = exp(-i/65536. * log(2.)) * (65536. * 65536); + double error = png_exp(i) - correct; + + if (fabs(error) > maxerr) + maxerr = fabs(error); + if (fabs(error) > 1883) /* By experiment. */ + { + fprintf(stderr, "32 bit exp error: %d: got %u, expected %f" + " error: %f\n", i, png_exp(i), correct, error); + } + } + + if (!silent) + printf("maximum 32 bit exp error = %f\n", maxerr); + + maxerr = 0; + for (i=0; i<=0xfffff; ++i) + { + double correct = exp(-i/65536. * log(2.)) * 255; + double error = png_exp8bit(i) - correct; + + if (fabs(error) > maxerr) + maxerr = fabs(error); + if (fabs(error) > .50002) /* By experiment */ + { + fprintf(stderr, "8 bit exp error: %d: got %u, expected %f" + " error: %f\n", i, png_exp8bit(i), correct, error); + } + } + + if (!silent) + printf("maximum 8 bit exp error = %f\n", maxerr); + + maxerr = 0; + for (i=0; i<=0xfffff; ++i) + { + double correct = exp(-i/65536. * log(2.)) * 65535; + double error = png_exp16bit(i) - correct; + + if (fabs(error) > maxerr) + maxerr = fabs(error); + if (fabs(error) > .524) /* By experiment */ + { + fprintf(stderr, "16 bit exp error: %d: got %u, expected %f" + " error: %f\n", i, png_exp16bit(i), correct, error); + } + } + + if (!silent) + printf("maximum 16 bit exp error = %f\n", maxerr); + } /* !onlygamma */ + + /* Test the overall gamma correction. */ + for (i=0; i<9; ++i) + { + unsigned j; + double g = gamma[i]; + png_fixed_point gfp = floor(g * PNG_FP_1 + .5); + + if (!silent) + printf("Test gamma %f\n", g); + + maxerr = 0; + for (j=0; j<256; ++j) + { + double correct = pow(j/255., g) * 255; + png_byte out = png_gamma_8bit_correct(j, gfp); + double error = out - correct; + + if (fabs(error) > maxerr) + maxerr = fabs(error); + if (out != floor(correct+.5)) + { + fprintf(stderr, "8bit %d ^ %f: got %d expected %f error %f\n", + j, g, out, correct, error); + } + } + + if (!silent) + printf("gamma %f: maximum 8 bit error %f\n", g, maxerr); + + maxerr = 0; + for (j=0; j<65536; ++j) + { + double correct = pow(j/65535., g) * 65535; + png_uint_16 out = png_gamma_16bit_correct(j, gfp); + double error = out - correct; + + if (fabs(error) > maxerr) + maxerr = fabs(error); + if (fabs(error) > 1.62) + { + fprintf(stderr, "16bit %d ^ %f: got %d expected %f error %f\n", + j, g, out, correct, error); + } + } + + if (!silent) + printf("gamma %f: maximum 16 bit error %f\n", g, maxerr); + } + + return 0; +} + +/**************************** VALIDATION TESTS ********************************/ +/* Various validation routines are included herein, they require some + * definition for png_warning and png_error, seetings of VALIDATION: + * + * 1: validates the ASCII to floating point conversions + * 2: validates png_muldiv + * 3: accuracy test of fixed point gamma tables + */ + +/* The following COUNT (10^8) takes about 1 hour on a 1GHz Pentium IV + * processor. + */ +#define COUNT 1000000000 + +int main(int argc, char **argv) +{ + int count = COUNT; + + while (argc > 1) + { + if (argc > 2 && strcmp(argv[1], "-c") == 0) + { + count = atoi(argv[2]); + argc -= 2; + argv += 2; + } + + else if (strcmp(argv[1], "-v") == 0) + { + ++verbose; + --argc; + ++argv; + } + + else + break; + } + + if (count > 0 && argc > 1) + { + if (strcmp(argv[1], "ascii") == 0) + return validation_ascii_to_fp(count, argc-1, argv+1); + else if (strcmp(argv[1], "checkfp") == 0) + return validation_checkfp(count, argc-1, argv+1); + else if (strcmp(argv[1], "muldiv") == 0) + return validation_muldiv(count, argc-1, argv+1); + else if (strcmp(argv[1], "gamma") == 0) + return validation_gamma(argc-1, argv+1); + } + + /* Bad argument: */ + fprintf(stderr, + "usage: tarith [-v] [-c count] {ascii,muldiv,gamma} [args]\n"); + fprintf(stderr, " arguments: ascii [-a (all results)] [-e error%%]\n"); + fprintf(stderr, " checkfp [-l max-number-chars]\n"); + fprintf(stderr, " muldiv\n"); + fprintf(stderr, " gamma -s (silent) -g (only gamma; no log)\n"); + return 1; +} diff --git a/libpng/contrib/libtests/timepng.c b/libpng/contrib/libtests/timepng.c new file mode 100644 index 000000000..7c937971c --- /dev/null +++ b/libpng/contrib/libtests/timepng.c @@ -0,0 +1,303 @@ +/* timepng.c + * + * Copyright (c) 2013 John Cunningham Bowler + * + * Last changed in libpng 1.6.1 [March 28, 2013] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * Load an arbitrary number of PNG files (from the command line, or, if there + * are no arguments on the command line, from stdin) then run a time test by + * reading each file by row. The test does nothing with the read result and + * does no transforms. The only output is a time as a floating point number of + * seconds with 9 decimal digits. + */ +#define _POSIX_C_SOURCE 199309L /* for clock_gettime */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#include <time.h> + +#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) +# include <config.h> +#endif + +/* Define the following to use this test against your installed libpng, rather + * than the one being built here: + */ +#ifdef PNG_FREESTANDING_TESTS +# include <png.h> +#else +# include "../../png.h" +#endif + +static int read_png(FILE *fp) +{ + png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0); + png_infop info_ptr = NULL; + png_bytep row = NULL, display = NULL; + + if (png_ptr == NULL) + return 0; + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + if (row != NULL) free(row); + if (display != NULL) free(display); + return 0; + } + + png_init_io(png_ptr, fp); + + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + png_error(png_ptr, "OOM allocating info structure"); + + png_read_info(png_ptr, info_ptr); + + { + png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + row = malloc(rowbytes); + display = malloc(rowbytes); + + if (row == NULL || display == NULL) + png_error(png_ptr, "OOM allocating row buffers"); + + { + png_uint_32 height = png_get_image_height(png_ptr, info_ptr); + int passes = png_set_interlace_handling(png_ptr); + int pass; + + png_start_read_image(png_ptr); + + for (pass = 0; pass < passes; ++pass) + { + png_uint_32 y = height; + + /* NOTE: this trashes the row each time; interlace handling won't + * work, but this avoids memory thrashing for speed testing. + */ + while (y-- > 0) + png_read_row(png_ptr, row, display); + } + } + } + + /* Make sure to read to the end of the file: */ + png_read_end(png_ptr, info_ptr); + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + free(row); + free(display); + return 1; +} + +static int mytime(struct timespec *t) +{ + /* Do the timing using clock_gettime and the per-process timer. */ + if (!clock_gettime(CLOCK_PROCESS_CPUTIME_ID, t)) + return 1; + + perror("CLOCK_PROCESS_CPUTIME_ID"); + fprintf(stderr, "timepng: could not get the time\n"); + return 0; +} + +static int perform_one_test(FILE *fp, int nfiles) +{ + int i; + struct timespec before, after; + + /* Clear out all errors: */ + rewind(fp); + + if (mytime(&before)) + { + for (i=0; i<nfiles; ++i) + { + if (read_png(fp)) + { + if (ferror(fp)) + { + perror("temporary file"); + fprintf(stderr, "file %d: error reading PNG data\n", i); + return 0; + } + } + + else + { + perror("temporary file"); + fprintf(stderr, "file %d: error from libpng\n", i); + return 0; + } + } + } + + else + return 0; + + if (mytime(&after)) + { + /* Work out the time difference and print it - this is the only output, + * so flush it immediately. + */ + unsigned long s = after.tv_sec - before.tv_sec; + long ns = after.tv_nsec - before.tv_nsec; + + if (ns < 0) + { + --s; + ns += 1000000000; + + if (ns < 0) + { + fprintf(stderr, "timepng: bad clock from kernel\n"); + return 0; + } + } + + printf("%lu.%.9ld\n", s, ns); + fflush(stdout); + if (ferror(stdout)) + { + fprintf(stderr, "timepng: error writing output\n"); + return 0; + } + + /* Successful return */ + return 1; + } + + else + return 0; +} + +static int add_one_file(FILE *fp, char *name) +{ + FILE *ip = fopen(name, "rb"); + + if (ip != NULL) + { + int ch; + for (;;) + { + ch = getc(ip); + if (ch == EOF) break; + putc(ch, fp); + } + + if (ferror(ip)) + { + perror(name); + fprintf(stderr, "%s: read error\n", name); + return 0; + } + + (void)fclose(ip); + + if (ferror(fp)) + { + perror("temporary file"); + fprintf(stderr, "temporary file write error\n"); + return 0; + } + } + + else + { + perror(name); + fprintf(stderr, "%s: open failed\n", name); + return 0; + } + + return 1; +} + +int main(int argc, char **argv) +{ + int ok = 0; + FILE *fp = tmpfile(); + + if (fp != NULL) + { + int err = 0; + int nfiles = 0; + + if (argc > 1) + { + int i; + + for (i=1; i<argc; ++i) + { + if (add_one_file(fp, argv[i])) + ++nfiles; + + else + { + err = 1; + break; + } + } + } + + else + { + char filename[FILENAME_MAX+1]; + + while (fgets(filename, FILENAME_MAX+1, stdin)) + { + size_t len = strlen(filename); + + if (filename[len-1] == '\n') + { + filename[len-1] = 0; + if (add_one_file(fp, filename)) + ++nfiles; + + else + { + err = 1; + break; + } + } + + else + { + fprintf(stderr, "timepng: truncated file name ...%s\n", + filename+len-32); + err = 1; + break; + } + } + + if (ferror(stdin)) + { + fprintf(stderr, "timepng: stdin: read error\n"); + err = 1; + } + } + + if (!err) + { + if (nfiles > 0) + ok = perform_one_test(fp, nfiles); + + else + fprintf(stderr, "usage: timepng {files} or ls files | timepng\n"); + } + + (void)fclose(fp); + } + + else + fprintf(stderr, "timepng: could not open temporary file\n"); + + /* Exit code 0 on success. */ + return ok == 0; +} |