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author | Glenn Randers-Pehrson <glennrp at users.sourceforge.net> | 1999-10-14 07:43:10 -0500 |
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committer | Glenn Randers-Pehrson <glennrp at users.sourceforge.net> | 2009-04-06 16:04:42 -0500 |
commit | 860ab2b1c02759c61efb5d63d2b07bd0d484a4c4 (patch) | |
tree | d81eec765bc267adc41041b09e67cfdb086c4af4 /contrib/gregbook/rpng-win.c | |
parent | ad5dd1f0fbbe69af3406eb4699637bf7ea99d587 (diff) | |
download | libpng-1.0.5.tar.gz |
Imported from libpng-1.0.5.tarv1.0.5
Diffstat (limited to 'contrib/gregbook/rpng-win.c')
-rw-r--r-- | contrib/gregbook/rpng-win.c | 600 |
1 files changed, 600 insertions, 0 deletions
diff --git a/contrib/gregbook/rpng-win.c b/contrib/gregbook/rpng-win.c new file mode 100644 index 000000000..346013201 --- /dev/null +++ b/contrib/gregbook/rpng-win.c @@ -0,0 +1,600 @@ +/*--------------------------------------------------------------------------- + + rpng - simple PNG display program rpng-win.c + + This program decodes and displays PNG images, with gamma correction and + optionally with a user-specified background color (in case the image has + transparency). It is very nearly the most basic PNG viewer possible. + This version is for 32-bit Windows; it may compile under 16-bit Windows + with a little tweaking (or maybe not). + + to do: + - stdout/stderr don't work! need message window (maybe scrollable?) + - handle quoted command-line args (especially filenames with spaces) + - have minimum window width: oh well + - use %.1023s to simplify truncation of title-bar string? + + --------------------------------------------------------------------------- + + Copyright (c) 1998-1999 Greg Roelofs. All rights reserved. + + This software is provided "as is," without warranty of any kind, + express or implied. In no event shall the author or contributors + be held liable for any damages arising in any way from the use of + this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute + it freely, subject to the following restrictions: + + 1. Redistributions of source code must retain the above copyright + notice, disclaimer, and this list of conditions. + 2. Redistributions in binary form must reproduce the above copyright + notice, disclaimer, and this list of conditions in the documenta- + tion and/or other materials provided with the distribution. + 3. All advertising materials mentioning features or use of this + software must display the following acknowledgment: + + This product includes software developed by Greg Roelofs + and contributors for the book, "PNG: The Definitive Guide," + published by O'Reilly and Associates. + + ---------------------------------------------------------------------------*/ + +#define PROGNAME "rpng-win" +#define LONGNAME "Simple PNG Viewer for Windows" +#define VERSION "1.0 of 20 February 1999" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <windows.h> + +/* #define DEBUG : this enables the Trace() macros */ + +#include "readpng.h" /* typedefs, common macros, readpng prototypes */ + + +/* could just include png.h, but this macro is the only thing we need + * (name and typedefs changed to local versions); note that side effects + * only happen with alpha (which could easily be avoided with + * "ush acopy = (alpha);") */ + +#define alpha_composite(composite, fg, alpha, bg) { \ + ush temp = ((ush)(fg)*(ush)(alpha) + \ + (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128); \ + (composite) = (uch)((temp + (temp >> 8)) >> 8); \ +} + + +/* local prototypes */ +static int rpng_win_create_window(HINSTANCE hInst, int showmode); +static int rpng_win_display_image(void); +static void rpng_win_cleanup(void); +LRESULT CALLBACK rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM); + + +static char titlebar[1024], *window_name = titlebar; +static char *progname = PROGNAME; +static char *appname = LONGNAME; +static char *icon_name = PROGNAME; /* GRR: not (yet) used */ +static char *filename; +static FILE *infile; + +static char *bgstr; +static uch bg_red=0, bg_green=0, bg_blue=0; + +static double display_exponent; + +static ulg image_width, image_height, image_rowbytes; +static int image_channels; +static uch *image_data; + +/* Windows-specific variables */ +static ulg wimage_rowbytes; +static uch *dib; +static uch *wimage_data; +static BITMAPINFOHEADER *bmih; + +static HWND global_hwnd; + + + + +int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode) +{ + char *args[1024]; /* arbitrary limit, but should suffice */ + char *p, *q, **argv = args; + int argc = 0; + int rc, alen, flen; + int error = 0; + int have_bg = FALSE; + double LUT_exponent; /* just the lookup table */ + double CRT_exponent = 2.2; /* just the monitor */ + double default_display_exponent; /* whole display system */ + MSG msg; + + + filename = (char *)NULL; + + + /* First set the default value for our display-system exponent, i.e., + * the product of the CRT exponent and the exponent corresponding to + * the frame-buffer's lookup table (LUT), if any. This is not an + * exhaustive list of LUT values (e.g., OpenStep has a lot of weird + * ones), but it should cover 99% of the current possibilities. And + * yes, these ifdefs are completely wasted in a Windows program... */ + +#if defined(NeXT) + LUT_exponent = 1.0 / 2.2; + /* + if (some_next_function_that_returns_gamma(&next_gamma)) + LUT_exponent = 1.0 / next_gamma; + */ +#elif defined(sgi) + LUT_exponent = 1.0 / 1.7; + /* there doesn't seem to be any documented function to get the + * "gamma" value, so we do it the hard way */ + infile = fopen("/etc/config/system.glGammaVal", "r"); + if (infile) { + double sgi_gamma; + + fgets(tmpline, 80, infile); + fclose(infile); + sgi_gamma = atof(tmpline); + if (sgi_gamma > 0.0) + LUT_exponent = 1.0 / sgi_gamma; + } +#elif defined(Macintosh) + LUT_exponent = 1.8 / 2.61; + /* + if (some_mac_function_that_returns_gamma(&mac_gamma)) + LUT_exponent = mac_gamma / 2.61; + */ +#else + LUT_exponent = 1.0; /* assume no LUT: most PCs */ +#endif + + /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */ + default_display_exponent = LUT_exponent * CRT_exponent; + + + /* If the user has set the SCREEN_GAMMA environment variable as suggested + * (somewhat imprecisely) in the libpng documentation, use that; otherwise + * use the default value we just calculated. Either way, the user may + * override this via a command-line option. */ + + if ((p = getenv("SCREEN_GAMMA")) != NULL) + display_exponent = atof(p); + else + display_exponent = default_display_exponent; + + + /* Windows really hates command lines, so we have to set up our own argv. + * Note that we do NOT bother with quoted arguments here, so don't use + * filenames with spaces in 'em! */ + + argv[argc++] = PROGNAME; + p = cmd; + for (;;) { + if (*p == ' ') + while (*++p == ' ') + ; + /* now p points at the first non-space after some spaces */ + if (*p == '\0') + break; /* nothing after the spaces: done */ + argv[argc++] = q = p; + while (*q && *q != ' ') + ++q; + /* now q points at a space or the end of the string */ + if (*q == '\0') + break; /* last argv already terminated; quit */ + *q = '\0'; /* change space to terminator */ + p = q + 1; + } + argv[argc] = NULL; /* terminate the argv array itself */ + + + /* Now parse the command line for options and the PNG filename. */ + + while (*++argv && !error) { + if (!strcmp(*argv, "-gamma")) { + if (!*++argv) + ++error; + display_exponent = atof(*argv); + if (display_exponent <= 0.0) + ++error; + } else if (!strcmp(*argv, "-bgcolor")) { + if (!*++argv) + ++error; + bgstr = *argv; + if (strlen(bgstr) != 7 || bgstr[0] != '#') + ++error; + else + have_bg = TRUE; + } else { + if (**argv != '-') { + filename = *argv; + if (argv[1]) /* shouldn't be any more args after filename */ + ++error; + } else + ++error; /* not expecting any other options */ + } + } + + if (!filename) { + ++error; + } else if (!(infile = fopen(filename, "rb"))) { + fprintf(stderr, PROGNAME ": can't open PNG file [%s]\n", filename); + ++error; + } else { + if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) { + switch (rc) { + case 1: + fprintf(stderr, PROGNAME + ": [%s] is not a PNG file: incorrect signature\n", + filename); + break; + case 2: + fprintf(stderr, PROGNAME + ": [%s] has bad IHDR (libpng longjmp)\n", + filename); + break; + case 4: + fprintf(stderr, PROGNAME ": insufficient memory\n"); + break; + default: + fprintf(stderr, PROGNAME + ": unknown readpng_init() error\n"); + break; + } + ++error; + } + if (error) + fclose(infile); + } + + if (error) { + fprintf(stderr, "\n%s %s: %s\n", PROGNAME, VERSION, appname); + readpng_version_info(); + fprintf(stderr, "\n" + "Usage: %s [-gamma exp] [-bgcolor bg] file.png\n" + " exp \ttransfer-function exponent (``gamma'') of the display\n" + "\t\t system in floating-point format (e.g., ``%.1f''); equal\n" + "\t\t to the product of the lookup-table exponent (varies)\n" + "\t\t and the CRT exponent (usually 2.2); must be positive\n" + " bg \tdesired background color in 7-character hex RGB format\n" + "\t\t (e.g., ``#ff7f00'' for orange: same as HTML colors);\n" + "\t\t used with transparent images\n" + "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n" + "\n", PROGNAME, default_display_exponent); + exit(1); + } + + + /* set the title-bar string, but make sure buffer doesn't overflow */ + + alen = strlen(appname); + flen = strlen(filename); + if (alen + flen + 3 > 1023) + sprintf(titlebar, "%s: ...%s", appname, filename+(alen+flen+6-1023)); + else + sprintf(titlebar, "%s: %s", appname, filename); + + + /* if the user didn't specify a background color on the command line, + * check for one in the PNG file--if not, the initialized values of 0 + * (black) will be used */ + + if (have_bg) + sscanf(bgstr+1, "%2x%2x%2x", &bg_red, &bg_green, &bg_blue); + else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) { + readpng_cleanup(TRUE); + fprintf(stderr, PROGNAME + ": libpng error while checking for background color\n"); + exit(2); + } + + + /* do the basic Windows initialization stuff, make the window and fill it + * with the background color */ + + if (rpng_win_create_window(hInst, showmode)) + exit(2); + + + /* decode the image, all at once */ + + Trace((stderr, "calling readpng_get_image()\n")) + image_data = readpng_get_image(display_exponent, &image_channels, + &image_rowbytes); + Trace((stderr, "done with readpng_get_image()\n")) + + + /* done with PNG file, so clean up to minimize memory usage (but do NOT + * nuke image_data!) */ + + readpng_cleanup(FALSE); + fclose(infile); + + if (!image_data) { + fprintf(stderr, PROGNAME ": unable to decode PNG image\n"); + exit(3); + } + + + /* display image (composite with background if requested) */ + + Trace((stderr, "calling rpng_win_display_image()\n")) + if (rpng_win_display_image()) { + free(image_data); + exit(4); + } + Trace((stderr, "done with rpng_win_display_image()\n")) + + + /* wait for the user to tell us when to quit */ + + while (GetMessage(&msg, NULL, 0, 0)) { + TranslateMessage(&msg); + DispatchMessage(&msg); + } + + + /* OK, we're done: clean up all image and Windows resources and go away */ + + rpng_win_cleanup(); + + return msg.wParam; +} + + + + + +static int rpng_win_create_window(HINSTANCE hInst, int showmode) +{ + uch *dest; + int extra_width, extra_height; + ulg i, j; + WNDCLASSEX wndclass; + + +/*--------------------------------------------------------------------------- + Allocate memory for the display-specific version of the image (round up + to multiple of 4 for Windows DIB). + ---------------------------------------------------------------------------*/ + + wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2; + + if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) + + wimage_rowbytes*image_height))) + { + return 4; /* fail */ + } + +/*--------------------------------------------------------------------------- + Initialize the DIB. Negative height means to use top-down BMP ordering + (must be uncompressed, but that's what we want). Bit count of 1, 4 or 8 + implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values + directly => wimage_data begins immediately after BMP header. + ---------------------------------------------------------------------------*/ + + memset(dib, 0, sizeof(BITMAPINFOHEADER)); + bmih = (BITMAPINFOHEADER *)dib; + bmih->biSize = sizeof(BITMAPINFOHEADER); + bmih->biWidth = image_width; + bmih->biHeight = -((long)image_height); + bmih->biPlanes = 1; + bmih->biBitCount = 24; + bmih->biCompression = 0; + wimage_data = dib + sizeof(BITMAPINFOHEADER); + +/*--------------------------------------------------------------------------- + Fill in background color (black by default); data are in BGR order. + ---------------------------------------------------------------------------*/ + + for (j = 0; j < image_height; ++j) { + dest = wimage_data + j*wimage_rowbytes; + for (i = image_width; i > 0; --i) { + *dest++ = bg_blue; + *dest++ = bg_green; + *dest++ = bg_red; + } + } + +/*--------------------------------------------------------------------------- + Set the window parameters. + ---------------------------------------------------------------------------*/ + + memset(&wndclass, 0, sizeof(wndclass)); + + wndclass.cbSize = sizeof(wndclass); + wndclass.style = CS_HREDRAW | CS_VREDRAW; + wndclass.lpfnWndProc = rpng_win_wndproc; + wndclass.hInstance = hInst; + wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION); + wndclass.hCursor = LoadCursor(NULL, IDC_ARROW); + wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH); + wndclass.lpszMenuName = NULL; + wndclass.lpszClassName = progname; + wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION); + + RegisterClassEx(&wndclass); + +/*--------------------------------------------------------------------------- + Finally, create the window. + ---------------------------------------------------------------------------*/ + + extra_width = 2*(GetSystemMetrics(SM_CXBORDER) + + GetSystemMetrics(SM_CXDLGFRAME)); + extra_height = 2*(GetSystemMetrics(SM_CYBORDER) + + GetSystemMetrics(SM_CYDLGFRAME)) + + GetSystemMetrics(SM_CYCAPTION); + + global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW, + CW_USEDEFAULT, CW_USEDEFAULT, image_width+extra_width, + image_height+extra_height, NULL, NULL, hInst, NULL); + + ShowWindow(global_hwnd, showmode); + UpdateWindow(global_hwnd); + + return 0; + +} /* end function rpng_win_create_window() */ + + + + + +static int rpng_win_display_image() +{ + uch *src, *dest; + uch r, g, b, a; + ulg i, row, lastrow; + RECT rect; + + + Trace((stderr, "beginning display loop (image_channels == %d)\n", + image_channels)) + Trace((stderr, "(width = %ld, rowbytes = %ld, wimage_rowbytes = %d)\n", + image_width, image_rowbytes, wimage_rowbytes)) + + +/*--------------------------------------------------------------------------- + Blast image data to buffer. This whole routine takes place before the + message loop begins, so there's no real point in any pseudo-progressive + display... + ---------------------------------------------------------------------------*/ + + for (lastrow = row = 0; row < image_height; ++row) { + src = image_data + row*image_rowbytes; + dest = wimage_data + row*wimage_rowbytes; + if (image_channels == 3) { + for (i = image_width; i > 0; --i) { + r = *src++; + g = *src++; + b = *src++; + *dest++ = b; + *dest++ = g; /* note reverse order */ + *dest++ = r; + } + } else /* if (image_channels == 4) */ { + for (i = image_width; i > 0; --i) { + r = *src++; + g = *src++; + b = *src++; + a = *src++; + if (a == 255) { + *dest++ = b; + *dest++ = g; + *dest++ = r; + } else if (a == 0) { + *dest++ = bg_blue; + *dest++ = bg_green; + *dest++ = bg_red; + } else { + /* this macro (copied from png.h) composites the + * foreground and background values and puts the + * result into the first argument; there are no + * side effects with the first argument */ + alpha_composite(*dest++, b, a, bg_blue); + alpha_composite(*dest++, g, a, bg_green); + alpha_composite(*dest++, r, a, bg_red); + } + } + } + /* display after every 16 lines */ + if (((row+1) & 0xf) == 0) { + rect.left = 0L; + rect.top = (LONG)lastrow; + rect.right = (LONG)image_width; /* possibly off by one? */ + rect.bottom = (LONG)lastrow + 16L; /* possibly off by one? */ + InvalidateRect(global_hwnd, &rect, FALSE); + UpdateWindow(global_hwnd); /* similar to XFlush() */ + lastrow = row + 1; + } + } + + Trace((stderr, "calling final image-flush routine\n")) + if (lastrow < image_height) { + rect.left = 0L; + rect.top = (LONG)lastrow; + rect.right = (LONG)image_width; /* possibly off by one? */ + rect.bottom = (LONG)image_height; /* possibly off by one? */ + InvalidateRect(global_hwnd, &rect, FALSE); + UpdateWindow(global_hwnd); /* similar to XFlush() */ + } + +/* + last param determines whether or not background is wiped before paint + InvalidateRect(global_hwnd, NULL, TRUE); + UpdateWindow(global_hwnd); + */ + + return 0; +} + + + + + +static void rpng_win_cleanup() +{ + if (image_data) { + free(image_data); + image_data = NULL; + } + + if (dib) { + free(dib); + dib = NULL; + } +} + + + + + +LRESULT CALLBACK rpng_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP) +{ + HDC hdc; + PAINTSTRUCT ps; + int rc; + + switch (iMsg) { + case WM_CREATE: + /* one-time processing here, if any */ + return 0; + + case WM_PAINT: + hdc = BeginPaint(hwnd, &ps); + /* dest */ + rc = StretchDIBits(hdc, 0, 0, image_width, image_height, + /* source */ + 0, 0, image_width, image_height, + wimage_data, (BITMAPINFO *)bmih, + /* iUsage: no clue */ + 0, SRCCOPY); + EndPaint(hwnd, &ps); + return 0; + + /* wait for the user to tell us when to quit */ + case WM_CHAR: + switch (wP) { /* only need one, so ignore repeat count */ + case 'q': + case 'Q': + case 0x1B: /* Esc key */ + PostQuitMessage(0); + } + return 0; + + case WM_LBUTTONDOWN: /* another way of quitting */ + case WM_DESTROY: + PostQuitMessage(0); + return 0; + } + + return DefWindowProc(hwnd, iMsg, wP, lP); +} |