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# font.h: operations on fonts independent of a particular file format.
#
# Copyright (C) 1992, 2011 Free Software Foundation, Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
#ifndef FONT_LIBRARY_H
#define FONT_LIBRARY_H
#include "bitmap.h"
#include "bounding-box.h"
#include "tfm.h"
#include "types.h"
/* A font is a collection of characters, generally at a particular point
size and resolution. The `bitmap_font_type' structure holds
information that comes entirely from a bitmap file. */
typedef struct
{
real design_size;
string comment;
unsigned checksum;
string filename;
} bitmap_font_type;
/* The design size is given in points. It is not necessarily
related to the actual dimensions of any of the characters in the
font; indeed, usually the design size is quite a bit larger than the
largest characters. */
#define BITMAP_FONT_DESIGN_SIZE(f) ((f).design_size)
/* Sometimes a font comes with a comment identifying its source, who
owns the trademark, or some such. */
#define BITMAP_FONT_COMMENT(f) ((f).comment)
/* The checksum found in the bitmap file. */
#define BITMAP_FONT_CHECKSUM(f) ((f).checksum)
/* The full pathname for the file that we opened. */
#define BITMAP_FONT_FILENAME(f) ((f).filename)
/* Look for a font named FONT_NAME in PK or GF format, at resolution
DPI. This ignores any extension in FONT_NAME; it adds `.<dpi>gf' or
`.<dpi>pk'. The font is looked for using the PKFONTS, GFFONTS, and
TEXFONTS environment variables, just as with the TeX software. If
the font can't be found, this gives a fatal error. */
extern bitmap_font_type get_bitmap_font (string font_name, unsigned dpi);
/* `close_font', below, works for bitmap fonts, too. */
/* The `font_info_type' holds a `bitmap_font_type', and additional
information that we get from a font metric file. */
typedef struct
{
bitmap_font_type bitmap_font;
tfm_global_info_type tfm_font;
string tfm_filename;
} font_info_type;
/* The bitmap information that is associated with this font. */
#define FONT_BITMAP_FONT(f) ((f).bitmap_font)
/* The TFM information. */
#define FONT_TFM_FONT(f) ((f).tfm_font)
/* The full pathname for the TFM file that we opened. */
#define FONT_TFM_FILENAME(f) ((f).tfm_filename)
/* The design size is given in points. It is not necessarily
related to the actual dimensions of any of the characters in the
font; indeed, usually the design size is quite a bit larger than the
largest characters. */
#define FONT_DESIGN_SIZE(f) BITMAP_FONT_DESIGN_SIZE ((f).bitmap_font)
/* Sometimes a font comes with a comment identifying its source, who
owns the trademark, or some such. */
#define FONT_COMMENT(f) BITMAP_FONT_COMMENT ((f).bitmap_font)
/* This calls `get_bitmap_font'; in addition, it looks for FONT_NAME in
TFM format. If either the bitmap file or the metric file can't be
found, this gives a fatal error. */
extern font_info_type get_font (string font_name, unsigned dpi);
/* Close any open files associated with FONT_NAME, whether it was opened
with `get_bitmap_font' or `get_font'. */
extern void close_font (string font_name);
/* A character is a bitmap image, and is therefore at a particular size
and resolution. It is also at a particular position in a font.
Generally, characters also have `side bearings'---extra space at the
left and/or right of the character. (In some scripts, there is
also displacement above and/or below the character, but we don't take
that into account here.) */
typedef struct
{
charcode_type code;
int set_width;
fix_word tfm_width;
bounding_box_type bb;
bitmap_type bitmap;
} char_info_type;
/* The character code in our fonts is always between 0 and 255. */
#define CHARCODE(c) ((c).code)
/* The set width is given in pixels; it's the sum of the left side
bearing, the bitmap's width, and the right side bearing. */
#define CHAR_SET_WIDTH(c) ((c).set_width)
/* The TFM width is the character's true width divided by the design
size (expressed as a fix_word). */
#define CHAR_TFM_WIDTH(c) ((c).tfm_width)
/* Unlike the font's bounding box, the character bounding box is
guaranteed to be the tightest possible; i.e., no all-blank rows occur
at the top or bottom, and no all-blank columns occur at the left or
right. */
#define CHAR_BB(c) ((c).bb)
/* The pixels. See `bitmap.h'. */
#define CHAR_BITMAP(c) ((c).bitmap)
/* Abbreviations for the width and height of a character's bitmap. */
#define CHAR_BITMAP_WIDTH(c) BITMAP_WIDTH (CHAR_BITMAP (c))
#define CHAR_BITMAP_HEIGHT(c) BITMAP_HEIGHT (CHAR_BITMAP (c))
/* Abbreviations for the parts of the character's bounding box. */
#define CHAR_MIN_COL(c) MIN_COL (CHAR_BB (c))
#define CHAR_MAX_COL(c) MAX_COL (CHAR_BB (c))
#define CHAR_MIN_ROW(c) MIN_ROW (CHAR_BB (c))
#define CHAR_MAX_ROW(c) MAX_ROW (CHAR_BB (c))
/* The height of a character is how far it extends above the baseline. */
#define CHAR_HEIGHT(c) (CHAR_MAX_ROW (c) >= 0 ? CHAR_MAX_ROW (c) : 0)
/* The depth is far it extends below the baseline (but as a positive
number, e.g., if a character's bitmap goes down to row -4, the depth
is 4). */
#define CHAR_DEPTH(c) (CHAR_MIN_ROW (c) < 0 ? -CHAR_MIN_ROW (c) : 0)
/* Abbreviations for the left and right side bearings, unless someone
else has already defined such macros (in which case they presumably
don't want ours). */
#ifndef CHAR_LSB
#define CHAR_LSB CHAR_MIN_COL
#endif
#ifndef CHAR_RSB
#define CHAR_RSB(c) (CHAR_SET_WIDTH (c) - CHAR_MAX_COL (c))
#endif
/* Return the character numbered CODE in the font FONT_NAME, or NULL if
that character doesn't exist in that font. If `get_font' or
`get_bitmap_font' has not been previously called on FONT_NAME,
`get_char' gives a fatal error. */
extern char_info_type *get_char (string font_name, charcode_type code);
/* Print a plain text representation of the character C to the file F. */
extern void print_char (FILE *f, char_info_type c);
/* Typeset the TEXT in the font FONT_NAME, at a resolution of DPI. */
extern bitmap_type string_to_bitmap (string text,
string font_name, unsigned dpi);
/* A raw character is the byte string that defines the character in the
font file, in some format. */
typedef enum { pk_format, gf_format } bitmap_format_type;
typedef struct
{
bitmap_format_type bitmap_format;
charcode_type code;
one_byte *bytes;
unsigned allocated;
unsigned used;
bounding_box_type bb;
signed_4_bytes h_escapement;
fix_word tfm_width;
} raw_char_type;
/* CHARCODE works to access the character code of a `raw_char_type'
variable. Likewise for the bounding box, horizontal escapement, and
TFM width. */
/* The file format the character definition was read from. */
#define RAW_CHAR_BITMAP_FORMAT(rc) ((rc).bitmap_format)
/* The bytes in the file that comprise the character definition. */
#define RAW_CHAR_BYTES(rc) ((rc).bytes)
/* The number of allocated bytes to which the buffer points. */
#define RAW_CHAR_ALLOCATED(rc) ((rc).allocated)
/* The number of bytes actually used. */
#define RAW_CHAR_USED(rc) ((rc).used)
/* A convenience macro for the first unused byte. */
#define RAW_CHAR_UNUSED_START(rc) RAW_CHAR_BYTES (rc)[RAW_CHAR_USED (rc)]
/* Return the raw character numbered CODE in the font named FONT_NAME,
or NULL. The only useful operation on a raw character is to write it
to an output file with the appropriate format. */
extern raw_char_type *get_raw_char (string font_name,
charcode_type code);
/* Free all allocated storage in the raw character RAW_CHAR, including
the character itself. */
extern void free_raw_char (raw_char_type *raw_char);
/* Miscellanous constants. */
/* We will only deal with fonts that have at most this many characters,
although the bitmap formats allow more. */
#define MAX_CHARCODE 255
/* Some font formats have pointers within the file (to other places in
the file). The null value for such pointers is -1. */
#define NULL_BYTE_PTR (-1)
#endif /* not FONT_LIBRARY_H */
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