[bpt/emacs.git] / src / fontset.h

/* Header for fontset handler.
   Copyright (C) 1995, 1997 Electrotechnical Laboratory, JAPAN.
   Licensed to the Free Software Foundation.

This file is part of GNU Emacs.

GNU Emacs 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 2, or (at your option)
any later version.

GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#ifndef _FONTSET_H
#define _FONTSET_H

/* This data type is used for the font_table field of window system
   depending data area (e.g. struct x_display_info on X window).  */

struct font_info
{
  /* Pointer to window system dependent font structure.  On X window,
     this value should be coerced to (XFontStruct *).  */
  void *font;

  /* Index number of the font.  */
  int font_idx;

  /* Name to be used to find the font.  */
  char *name;

  /* Full name of the font given by a window system.  */
  char *full_name;

  /* Charset of characters displayed by the font.  */
  int charset;

  /* Maximum bound width over all existing characters of the font.  On
     X window, this is same as (font->max_bounds.width) */
  int size;

  /* Height of the font.  On X window, this is same as (font->ascent
     + font->descent).  */
  int height;

  /* 1 iff we render characters at vartical center positions of lines.  */
  int vertical_centering;

  /* Encodings of the font indexed by CHARSET.  The value an integer
     0, 1, 2, or 3:
	0: code points 0x20..0x7F or 0x2020..0x7F7F are used
	1: code points 0xA0..0xFF or 0xA0A0..0xFFFF are used
	2: code points 0x20A0..0x7FFF are used
	3: code points 0xA020..0xFF7F are used
     For instance, ASCII and Latin-1 characters may use the same font
     but different code points (ASCII uses 0x20..0x7F and Latin-1 uses
     0xA0..0xFF).

     If the value can't be decided from information of the font, we
     consult `font-encoding-alist' to get of the corresponding charset
     whose default value is defined in lisp/fontset.el.  Since there's
     no charset whose id is 1, we use encoding[1] to store the
     encoding information decided by the font itself.  */
  unsigned char encoding[MAX_CHARSET + 1];

  /* The baseline position of a font is normally `ascent' value of the
     font.  However, there exists many fonts which don't set `ascent'
     an appropriate value to be used as baseline position.  This is
     typical in such ASCII fonts which are designed to be used with
     Chinese, Japanese, Korean characters.  When we use mixture of
     such fonts and normal fonts (having correct `ascent' value), a
     display line gets very ugly.  Since we have no way to fix it
     automatically, it is users responsibility to supply well designed
     fonts or correct `ascent' value of fonts.  But, the latter
     requires heavy work (modifying all bitmap data in BDF files).
     So, Emacs accepts a private font property
     `_MULE_BASELINE_OFFSET'.  If a font has this property, we
     calculate the baseline position by subtracting the value from
     `ascent'.  In other words, the value indicates how many bits
     higher we should draw a character of the font than normal ASCII
     text for a better looking.
       
     We also have to consider the fact that the concept of `baseline'
     differs among languages to which each character belongs.  For
     instance, baseline should be at the bottom most position of all
     glyphs for Chinese, Japanese, and Korean.  But, many of existing
     fonts for those characters doesn't have correct `ascent' values
     because they are designed to be used with ASCII fonts.  To
     display characters of different language on the same line, the
     best way will be to arrange them in the middle of the line.  So,
     in such a case, again, we utilize the font property
     `_MULE_BASELINE_OFFSET'.  If the value is larger than `ascent' we
     calculate baseline so that a character is arranged in the middle
     of a line.  */

  int baseline_offset;

  /* Non zero means a character should be composed at a position
     relative to the height (or depth) of previous glyphs in the
     following cases:
	(1) The bottom of the character is higher than this value.  In
	this case, the character is drawn above the previous glyphs.
	(2) The top of the character is lower than 0 (i.e. baseline
	height).  In this case, the character is drawn beneath the
	previous glyphs.

     This value is taken from a private font property
     `_MULE_RELATIVE_COMPOSE' which is introduced by Emacs.  */
  int relative_compose;

  /* Non zero means an ascent value to be used for a character
     registered in char-table `use-default-ascent'.  */
  int default_ascent;

  /* CCL program to calculate code points of the font.  */
  struct ccl_program *font_encoder;
};

/* A value which may appear in the member encoding of struch font_info
   indicating that a font itself doesn't tell which encoding to be
   used.  */
#define FONT_ENCODING_NOT_DECIDED 255

#define FONT_NOT_OPENED -1
#define FONT_NOT_FOUND  -2

struct fontset_info
{
  /* Name of the fontset.  */
  char *name;

  /* Size of the fontset.  This is the same as the size of ASCII font
     of this fontset.  */
  int size;

  /* Height of the tallest font in the fontset.  */
  int height;

  /* Table of font name for each character set.  */
  char *fontname[MAX_CHARSET + 1];

  /* Table of index numbers of fonts indexed by charset.  If a font is
     not yet loaded, the value is -1 (FONT_NOT_OPENED).  If font
     loading is failed, the value is -2 (FONT_NOT_FOUND).  */
  int font_indexes[MAX_CHARSET + 1];
};

/* This data type is used for the fontset_data field of struct frame.  */

struct fontset_data
{
  /* A table of pointers to all the fontsets.  */
  struct fontset_info **fontset_table;

  /* The current capacity of fontset_table.  */
  int fontset_table_size;

  /* The number of fontsets actually stored in fontset_table.
     fontset_table[n] is used and valid iff 0 <= n < n_fontsets.
     0 <= n_fontsets <= fontset_table_size.  */
  int n_fontsets;
};

/* Forward declaration for prototypes.  */
struct frame;

/* The following six are window system dependent functions.
   Initialization routine of each window system should set appropriate
   functions to these variables.  For instance, in case of X window,
   x_term_init does this.  */

/* Return a pointer to struct font_info of font FONT_IDX of frame F.  */
extern struct font_info *(*get_font_info_func) P_ ((struct frame *f,
						    int font_idx));

/* Return a list of font names which matches PATTERN.  See the document of
   `x-list-fonts' for more detail.  */
extern Lisp_Object (*list_fonts_func) P_ ((struct frame *f,
					   Lisp_Object pattern,
					   int size,
					   int maxnames));

/* Load a font named NAME for frame F and return a pointer to the
   information of the loaded font.  If loading is failed, return -1.  */
extern struct font_info *(*load_font_func) P_ ((struct frame *f,
						char *name, int));

/* Return a pointer to struct font_info of a font named NAME for frame F.
   If no such font is loaded, return NULL.  */
extern struct font_info *(*query_font_func) P_ ((struct frame *f, char *name));

/* Additional function for setting fontset or changing fontset
   contents of frame F.  This function may change the coordinate of
   the frame.  */
extern void (*set_frame_fontset_func) P_ ((struct frame *f, Lisp_Object arg,
					   Lisp_Object oldval));

/* To find a CCL program, fs_load_font calls this function.
   The argument is a pointer to the struct font_info.
   This function set the memer `encoder' of the structure.  */
extern void (*find_ccl_program_func) P_ ((struct font_info *));

/* Check if any window system is used now.  */
extern void (*check_window_system_func) P_ ((void));

extern struct fontset_data *alloc_fontset_data P_ ((void));
extern void free_fontset_data P_ ((struct fontset_data *));
extern struct font_info *fs_load_font P_ ((struct frame *, struct font_info *,
					   int, char *, int));
extern int fs_query_fontset P_ ((struct frame *, char *));
extern int fs_register_fontset P_ ((struct frame *, Lisp_Object));
EXFUN (Fquery_fontset, 2);
extern Lisp_Object list_fontsets P_ ((struct frame *, Lisp_Object, int));
extern Lisp_Object Vglobal_fontset_alist;
struct frame;
int fs_query_fontset P_ ((struct frame *f, char *name));

extern Lisp_Object Qfontset;
extern Lisp_Object Vuse_default_ascent; 
extern Lisp_Object Vignore_relative_composition;
extern Lisp_Object Valternate_fontname_alist;
extern Lisp_Object Vhighlight_wrong_size_font;
extern Lisp_Object Vclip_large_size_font;
extern Lisp_Object Vvertical_centering_font_regexp;
extern int font_idx_temp;

/* Load a font named FONTNAME for displaying CHARSET on frame F.
   All fonts for frame F is stored in a table pointed by FONT_TABLE.
   Return a pointer to the struct font_info of the loaded font.
   If loading fails, return 0;
   If FONTNAME is NULL, the name is taken from the information of FONTSET.
   If FONTSET is given, try to load a font whose size matches that of
   FONTSET, and, the font index is stored in the table for FONTSET.  */

#define FS_LOAD_FONT(f, font_table, charset, fontname, fontset)		  \
  (fontset >= 0 && fontset < FRAME_FONTSET_DATA (f)->n_fontsets		  \
   && (font_idx_temp = (FRAME_FONTSET_DATA (f)				  \
			->fontset_table[fontset]->font_indexes[charset]), \
       font_idx_temp >= 0)						  \
   ? font_table + font_idx_temp						  \
   : fs_load_font (f, font_table, charset, fontname, fontset))

extern Lisp_Object Vfontset_alias_alist;
extern Lisp_Object Vglobal_fontset_alist;


/* Return an immutable id for font_info FONT_INFO on frame F.  The
   reason for this macro is hat one cannot hold pointers to font_info
   structures in other data structures, because the table is
   reallocated in x_list_fonts.  */

#define FONT_INFO_ID(F, FONT_INFO) \
     (FONT_INFO) - (FRAME_X_DISPLAY_INFO ((F))->font_table)

/* Given a font_info id ID, return a pointer to the font_info
   structure on frame F.  If ID is invalid, return null.  */

#define FONT_INFO_FROM_ID(F, ID)					\
     (((ID) >= 0 && (ID) < FRAME_X_DISPLAY_INFO ((F))->font_table_size)	\
      ? (FRAME_X_DISPLAY_INFO ((F))->font_table + (ID))			\
      : 0)

#endif /* _FONTSET_H */
Commit	Line	Data
4ed46869	1	/* Header for fontset handler.
75c8c592 RS	2	Copyright (C) 1995, 1997 Electrotechnical Laboratory, JAPAN.
75c8c592 RS	3	Licensed to the Free Software Foundation.
4ed46869	4
369314dc KH	5	This file is part of GNU Emacs.
	6
	7	GNU Emacs is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2, or (at your option)
	10	any later version.
4ed46869	11
369314dc KH	12	GNU Emacs is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
4ed46869	16
369314dc KH	17	You should have received a copy of the GNU General Public License
	18	along with GNU Emacs; see the file COPYING. If not, write to
	19	the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	20	Boston, MA 02111-1307, USA. */
4ed46869 KH	21
	22	#ifndef _FONTSET_H
	23	#define _FONTSET_H
	24
4ed46869 KH	25	/* This data type is used for the font_table field of window system
	26	depending data area (e.g. struct x_display_info on X window). */
	27
	28	struct font_info
	29	{
	30	/* Pointer to window system dependent font structure. On X window,
	31	this value should be coerced to (XFontStruct ). /
	32	void *font;
	33
	34	/* Index number of the font. */
	35	int font_idx;
	36
	37	/* Name to be used to find the font. */
	38	char *name;
	39
	40	/* Full name of the font given by a window system. */
	41	char *full_name;
	42
	43	/* Charset of characters displayed by the font. */
	44	int charset;
	45
	46	/* Maximum bound width over all existing characters of the font. On
	47	X window, this is same as (font->max_bounds.width) */
	48	int size;
	49
	50	/* Height of the font. On X window, this is same as (font->ascent
	51	+ font->descent). */
	52	int height;
	53
21fa1afa KH	54	/* 1 iff we render characters at vartical center positions of lines. */
	55	int vertical_centering;
	56
4ed46869 KH	57	/* Encodings of the font indexed by CHARSET. The value an integer
	58	0, 1, 2, or 3:
	59	0: code points 0x20..0x7F or 0x2020..0x7F7F are used
	60	1: code points 0xA0..0xFF or 0xA0A0..0xFFFF are used
	61	2: code points 0x20A0..0x7FFF are used
	62	3: code points 0xA020..0xFF7F are used
	63	For instance, ASCII and Latin-1 characters may use the same font
	64	but different code points (ASCII uses 0x20..0x7F and Latin-1 uses
	65	0xA0..0xFF).
	66
	67	If the value can't be decided from information of the font, we
	68	consult `font-encoding-alist' to get of the corresponding charset
	69	whose default value is defined in lisp/fontset.el. Since there's
	70	no charset whose id is 1, we use encoding[1] to store the
	71	encoding information decided by the font itself. */
d987e6cb	72	unsigned char encoding[MAX_CHARSET + 1];
4ed46869 KH	73
	74	/* The baseline position of a font is normally `ascent' value of the
	75	font. However, there exists many fonts which don't set `ascent'
	76	an appropriate value to be used as baseline position. This is
	77	typical in such ASCII fonts which are designed to be used with
	78	Chinese, Japanese, Korean characters. When we use mixture of
	79	such fonts and normal fonts (having correct `ascent' value), a
	80	display line gets very ugly. Since we have no way to fix it
	81	automatically, it is users responsibility to supply well designed
	82	fonts or correct `ascent' value of fonts. But, the latter
	83	requires heavy work (modifying all bitmap data in BDF files).
	84	So, Emacs accepts a private font property
	85	`_MULE_BASELINE_OFFSET'. If a font has this property, we
	86	calculate the baseline position by subtracting the value from
	87	`ascent'. In other words, the value indicates how many bits
	88	higher we should draw a character of the font than normal ASCII
	89	text for a better looking.
	90
	91	We also have to consider the fact that the concept of `baseline'
	92	differs among languages to which each character belongs. For
	93	instance, baseline should be at the bottom most position of all
	94	glyphs for Chinese, Japanese, and Korean. But, many of existing
	95	fonts for those characters doesn't have correct `ascent' values
	96	because they are designed to be used with ASCII fonts. To
	97	display characters of different language on the same line, the
	98	best way will be to arrange them in the middle of the line. So,
	99	in such a case, again, we utilize the font property
	100	`_MULE_BASELINE_OFFSET'. If the value is larger than `ascent' we
	101	calculate baseline so that a character is arranged in the middle
	102	of a line. */
	103
	104	int baseline_offset;
	105
	106	/* Non zero means a character should be composed at a position
	107	relative to the height (or depth) of previous glyphs in the
	108	following cases:
	109	(1) The bottom of the character is higher than this value. In
	110	this case, the character is drawn above the previous glyphs.
	111	(2) The top of the character is lower than 0 (i.e. baseline
	112	height). In this case, the character is drawn beneath the
	113	previous glyphs.
	114
467e7675	115	This value is taken from a private font property
4ed46869 KH	116	`_MULE_RELATIVE_COMPOSE' which is introduced by Emacs. */
	117	int relative_compose;
	118
b65dbda3 KH	119	/* Non zero means an ascent value to be used for a character
	120	registered in char-table `use-default-ascent'. */
	121	int default_ascent;
	122
4ed46869 KH	123	/* CCL program to calculate code points of the font. */
	124	struct ccl_program *font_encoder;
	125	};
	126
71c27002 KH	127	/* A value which may appear in the member encoding of struch font_info
	128	indicating that a font itself doesn't tell which encoding to be
	129	used. */
c2c8997e	130	#define FONT_ENCODING_NOT_DECIDED 255
71c27002	131
4ed46869 KH	132	#define FONT_NOT_OPENED -1
	133	#define FONT_NOT_FOUND -2
	134
	135	struct fontset_info
	136	{
	137	/* Name of the fontset. */
	138	char *name;
	139
	140	/* Size of the fontset. This is the same as the size of ASCII font
	141	of this fontset. */
	142	int size;
	143
	144	/* Height of the tallest font in the fontset. */
	145	int height;
	146
	147	/* Table of font name for each character set. */
467e7675	148	char *fontname[MAX_CHARSET + 1];
4ed46869 KH	149
	150	/* Table of index numbers of fonts indexed by charset. If a font is
	151	not yet loaded, the value is -1 (FONT_NOT_OPENED). If font
	152	loading is failed, the value is -2 (FONT_NOT_FOUND). */
467e7675	153	int font_indexes[MAX_CHARSET + 1];
4ed46869 KH	154	};
	155
	156	/* This data type is used for the fontset_data field of struct frame. */
	157
	158	struct fontset_data
	159	{
	160	/* A table of pointers to all the fontsets. */
	161	struct fontset_info **fontset_table;
	162
	163	/* The current capacity of fontset_table. */
	164	int fontset_table_size;
	165
	166	/* The number of fontsets actually stored in fontset_table.
	167	fontset_table[n] is used and valid iff 0 <= n < n_fontsets.
	168	0 <= n_fontsets <= fontset_table_size. */
	169	int n_fontsets;
	170	};
	171
d748a3db AS	172	/* Forward declaration for prototypes. */
	173	struct frame;
	174
4ed46869 KH	175	/* The following six are window system dependent functions.
	176	Initialization routine of each window system should set appropriate
	177	functions to these variables. For instance, in case of X window,
	178	x_term_init does this. */
	179
	180	/* Return a pointer to struct font_info of font FONT_IDX of frame F. */
d748a3db AS	181	extern struct font_info (get_font_info_func) P_ ((struct frame *f,
d748a3db AS	182	int font_idx));
4ed46869 KH	183
	184	/* Return a list of font names which matches PATTERN. See the document of
	185	`x-list-fonts' for more detail. */
9625ce22 KH	186	extern Lisp_Object (list_fonts_func) P_ ((struct frame f,
	187	Lisp_Object pattern,
	188	int size,
	189	int maxnames));
4ed46869 KH	190
	191	/* Load a font named NAME for frame F and return a pointer to the
	192	information of the loaded font. If loading is failed, return -1. */
d748a3db AS	193	extern struct font_info (load_font_func) P_ ((struct frame *f,
d748a3db AS	194	char *name, int));
4ed46869 KH	195
	196	/* Return a pointer to struct font_info of a font named NAME for frame F.
	197	If no such font is loaded, return NULL. */
d748a3db	198	extern struct font_info (query_font_func) P_ ((struct frame f, char name));
4ed46869 KH	199
	200	/* Additional function for setting fontset or changing fontset
	201	contents of frame F. This function may change the coordinate of
	202	the frame. */
d748a3db AS	203	extern void (set_frame_fontset_func) P_ ((struct frame f, Lisp_Object arg,
d748a3db AS	204	Lisp_Object oldval));
4ed46869	205
c2c8997e KH	206	/* To find a CCL program, fs_load_font calls this function.
	207	The argument is a pointer to the struct font_info.
	208	This function set the memer `encoder' of the structure. */
	209	extern void (find_ccl_program_func) P_ ((struct font_info ));
	210
4ed46869	211	/* Check if any window system is used now. */
d748a3db AS	212	extern void (*check_window_system_func) P_ ((void));
	213
	214	extern struct fontset_data *alloc_fontset_data P_ ((void));
	215	extern void free_fontset_data P_ ((struct fontset_data *));
	216	extern struct font_info fs_load_font P_ ((struct frame , struct font_info *,
	217	int, char *, int));
	218	extern int fs_query_fontset P_ ((struct frame , char ));
	219	extern int fs_register_fontset P_ ((struct frame *, Lisp_Object));
c2c8997e	220	EXFUN (Fquery_fontset, 2);
d748a3db	221	extern Lisp_Object list_fontsets P_ ((struct frame *, Lisp_Object, int));
4ed46869	222	extern Lisp_Object Vglobal_fontset_alist;
e18f9922 GM	223	struct frame;
e18f9922 GM	224	int fs_query_fontset P_ ((struct frame f, char name));
4ed46869 KH	225
4ed46869 KH	226	extern Lisp_Object Qfontset;
b65dbda3	227	extern Lisp_Object Vuse_default_ascent;
32eb3f08	228	extern Lisp_Object Vignore_relative_composition;
015e1bb0	229	extern Lisp_Object Valternate_fontname_alist;
e497c1f3 KH	230	extern Lisp_Object Vhighlight_wrong_size_font;
e497c1f3 KH	231	extern Lisp_Object Vclip_large_size_font;
21fa1afa	232	extern Lisp_Object Vvertical_centering_font_regexp;
7bca5cf2 KH	233	extern int font_idx_temp;
	234
	235	/* Load a font named FONTNAME for displaying CHARSET on frame F.
	236	All fonts for frame F is stored in a table pointed by FONT_TABLE.
	237	Return a pointer to the struct font_info of the loaded font.
	238	If loading fails, return 0;
	239	If FONTNAME is NULL, the name is taken from the information of FONTSET.
	240	If FONTSET is given, try to load a font whose size matches that of
	241	FONTSET, and, the font index is stored in the table for FONTSET. */
	242
	243	#define FS_LOAD_FONT(f, font_table, charset, fontname, fontset) \
	244	(fontset >= 0 && fontset < FRAME_FONTSET_DATA (f)->n_fontsets \
	245	&& (font_idx_temp = (FRAME_FONTSET_DATA (f) \
	246	->fontset_table[fontset]->font_indexes[charset]), \
	247	font_idx_temp >= 0) \
	248	? font_table + font_idx_temp \
	249	: fs_load_font (f, font_table, charset, fontname, fontset))
	250
e18f9922 GM	251	extern Lisp_Object Vfontset_alias_alist;
	252	extern Lisp_Object Vglobal_fontset_alist;
	253
	254
	255	/* Return an immutable id for font_info FONT_INFO on frame F. The
	256	reason for this macro is hat one cannot hold pointers to font_info
	257	structures in other data structures, because the table is
	258	reallocated in x_list_fonts. */
	259
	260	#define FONT_INFO_ID(F, FONT_INFO) \
	261	(FONT_INFO) - (FRAME_X_DISPLAY_INFO ((F))->font_table)
	262
	263	/* Given a font_info id ID, return a pointer to the font_info
	264	structure on frame F. If ID is invalid, return null. */
	265
	266	#define FONT_INFO_FROM_ID(F, ID) \
	267	(((ID) >= 0 && (ID) < FRAME_X_DISPLAY_INFO ((F))->font_table_size) \
	268	? (FRAME_X_DISPLAY_INFO ((F))->font_table + (ID)) \
	269	: 0)
	270
d295ed3c	271	#endif /* _FONTSET_H */