1 /* Header for fontset handler.
2 Copyright (C) 1998, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007 Free Software Foundation, Inc.
4 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
6 National Institute of Advanced Industrial Science and Technology (AIST)
7 Registration Number H14PRO021
9 This file is part of GNU Emacs.
11 GNU Emacs is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2, or (at your option)
16 GNU Emacs is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with GNU Emacs; see the file COPYING. If not, write to
23 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 Boston, MA 02110-1301, USA. */
26 #ifndef EMACS_FONTSET_H
27 #define EMACS_FONTSET_H
29 /* This data type is used for the font_table field of window system
30 depending data area (e.g. struct x_display_info on X window). */
34 /* Pointer to window system dependent font structure. On X window,
35 this value should be coerced to (XFontStruct *). */
38 /* Index number of the font. */
41 /* Name to be used to find the font. */
44 /* Full name of the font given by a window system. */
47 /* Charset of characters displayed by the font. */
51 /* Codepage of characters that will be displayed by the font. */
55 /* Maximum bound width over all existing characters of the font. On
56 X window, this is same as (font->max_bounds.width) */
59 /* Height of the font. On X window, this is the same as
60 (font->ascent + font->descent). */
63 /* Width of the space glyph of the font. */
66 /* Average width of glyphs in the font. */
69 /* 1 iff `vertical-centering-font-regexp' matches this font name.
70 In this case, we render characters at vartical center positions
72 int vertical_centering
;
74 /* Encodings of the font indexed by CHARSET. The value is one of
76 0: code points 0x20..0x7F or 0x2020..0x7F7F are used
77 1: code points 0xA0..0xFF or 0xA0A0..0xFFFF are used
78 2: code points 0x20A0..0x7FFF are used
79 3: code points 0xA020..0xFF7F are used
80 For instance, ASCII and Latin-1 characters may use the same font
81 but different code points (ASCII uses 0x20..0x7F and Latin-1 uses
84 If the value can't be decided from information of the font, we
85 consult `font-encoding-alist' to get of the corresponding charset
86 whose default value is defined in lisp/fontset.el. Since there's
87 no charset whose id is 1, we use encoding[1] to store the
88 encoding information decided by the font itself.
90 If the member `font_encoder' is not NULL, this member is ignored.
92 unsigned char encoding
[MAX_CHARSET
+ 1];
94 /* The baseline position of a font is normally `ascent' value of the
95 font. However, there exists many fonts which don't set `ascent'
96 an appropriate value to be used as baseline position. This is
97 typical in such ASCII fonts which are designed to be used with
98 Chinese, Japanese, Korean characters. When we use mixture of
99 such fonts and normal fonts (having correct `ascent' value), a
100 display line gets very ugly. Since we have no way to fix it
101 automatically, it is users responsibility to supply well designed
102 fonts or correct `ascent' value of fonts. But, the latter
103 requires heavy work (modifying all bitmap data in BDF files).
104 So, Emacs accepts a private font property
105 `_MULE_BASELINE_OFFSET'. If a font has this property, we
106 calculate the baseline position by subtracting the value from
107 `ascent'. In other words, the value indicates how many bits
108 higher we should draw a character of the font than normal ASCII
109 text for a better looking.
111 We also have to consider the fact that the concept of `baseline'
112 differs among languages to which each character belongs. For
113 instance, baseline should be at the bottom most position of all
114 glyphs for Chinese, Japanese, and Korean. But, many of existing
115 fonts for those characters doesn't have correct `ascent' values
116 because they are designed to be used with ASCII fonts. To
117 display characters of different language on the same line, the
118 best way will be to arrange them in the middle of the line. So,
119 in such a case, again, we utilize the font property
120 `_MULE_BASELINE_OFFSET'. If the value is larger than `ascent' we
121 calculate baseline so that a character is arranged in the middle
126 /* Non zero means a character should be composed at a position
127 relative to the height (or depth) of previous glyphs in the
129 (1) The bottom of the character is higher than this value. In
130 this case, the character is drawn above the previous glyphs.
131 (2) The top of the character is lower than 0 (i.e. baseline
132 height). In this case, the character is drawn beneath the
135 This value is taken from a private font property
136 `_MULE_RELATIVE_COMPOSE' which is introduced by Emacs. */
137 int relative_compose
;
139 /* Non zero means an ascent value to be used for a character
140 registered in char-table `use-default-ascent'. */
143 /* CCL program to calculate code points of the font. */
144 struct ccl_program
*font_encoder
;
147 /* A value which may appear in the member `encoding' of struch
148 font_info indicating that a font itself doesn't tell which encoding
150 #define FONT_ENCODING_NOT_DECIDED 255
152 /* Forward declaration for prototypes. */
155 /* The following six are window system dependent functions.
156 Initialization routine of each window system should set appropriate
157 functions to these variables. For instance, in case of X window,
158 x_term_init does this. */
160 /* Return a pointer to struct font_info of font FONT_IDX of frame F. */
161 extern struct font_info
*(*get_font_info_func
) P_ ((struct frame
*f
,
164 /* Return a list of font names which matches PATTERN. See the document of
165 `x-list-fonts' for more detail. */
166 extern Lisp_Object (*list_fonts_func
) P_ ((struct frame
*f
,
171 /* Load a font named NAME for frame F and return a pointer to the
172 information of the loaded font. If loading is failed, return -1. */
173 extern struct font_info
*(*load_font_func
) P_ ((struct frame
*f
,
176 /* Return a pointer to struct font_info of a font named NAME for frame F.
177 If no such font is loaded, return NULL. */
178 extern struct font_info
*(*query_font_func
) P_ ((struct frame
*f
, char *name
));
180 /* Additional function for setting fontset or changing fontset
181 contents of frame F. This function may change the coordinate of
183 extern void (*set_frame_fontset_func
) P_ ((struct frame
*f
, Lisp_Object arg
,
184 Lisp_Object oldval
));
186 /* To find a CCL program, fs_load_font calls this function.
187 The argument is a pointer to the struct font_info.
188 This function set the memer `encoder' of the structure. */
189 extern void (*find_ccl_program_func
) P_ ((struct font_info
*));
191 /* Check if any window system is used now. */
192 extern void (*check_window_system_func
) P_ ((void));
196 extern void free_face_fontset
P_ ((FRAME_PTR
, struct face
*));
197 extern Lisp_Object fontset_font_pattern
P_ ((FRAME_PTR
, int, int));
198 extern int face_suitable_for_char_p
P_ ((struct face
*, int));
199 extern int face_for_char
P_ ((FRAME_PTR
, struct face
*, int));
200 extern int make_fontset_for_ascii_face
P_ ((FRAME_PTR
, int));
201 extern void set_default_ascii_font
P_ ((Lisp_Object
));
202 extern struct font_info
*fs_load_font
P_ ((struct frame
*, int, char *, int,
204 extern int fs_query_fontset
P_ ((Lisp_Object
, int));
205 EXFUN (Fquery_fontset
, 2);
206 extern Lisp_Object list_fontsets
P_ ((struct frame
*, Lisp_Object
, int));
208 extern Lisp_Object Qfontset
;
209 extern Lisp_Object Vuse_default_ascent
;
210 extern Lisp_Object Vignore_relative_composition
;
211 extern Lisp_Object Valternate_fontname_alist
;
212 extern Lisp_Object Vfontset_alias_alist
;
213 extern Lisp_Object Vvertical_centering_font_regexp
;
215 /* Load a font named FONTNAME for displaying character C. All fonts
216 for frame F is stored in a table pointed by FONT_TABLE. Return a
217 pointer to the struct font_info of the loaded font. If loading
218 fails, return 0; If FONTNAME is NULL, the name is taken from the
219 information of FONTSET. If FONTSET is given, try to load a font
220 whose size matches that of FONTSET, and, the font index is stored
221 in the table for FONTSET. */
223 #define FS_LOAD_FONT(f, c, fontname, fontset) \
224 fs_load_font (f, c, fontname, fontset, NULL)
226 #define FS_LOAD_FACE_FONT(f, c, fontname, face) \
227 fs_load_font (f, c, fontname, -1, face)
229 /* Return an immutable id for font_info FONT_INFO on frame F. The
230 reason for this macro is hat one cannot hold pointers to font_info
231 structures in other data structures, because the table is
232 reallocated in x_list_fonts. */
234 #define FONT_INFO_ID(F, FONT_INFO) \
235 (FONT_INFO) - (FRAME_X_DISPLAY_INFO ((F))->font_table)
237 /* Given a font_info id ID, return a pointer to the font_info
238 structure on frame F. If ID is invalid, return null. */
240 #define FONT_INFO_FROM_ID(F, ID) \
241 (((ID) >= 0 && (ID) < FRAME_X_DISPLAY_INFO ((F))->font_table_size) \
242 ? (FRAME_X_DISPLAY_INFO ((F))->font_table + (ID)) \
245 extern Lisp_Object fontset_name
P_ ((int));
246 extern Lisp_Object fontset_ascii
P_ ((int));
247 extern int fontset_height
P_ ((int));
249 #endif /* EMACS_FONTSET_H */
251 /* arch-tag: c27cef7b-3cab-488a-8398-7a4daa96bb77
252 (do not change this comment) */