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1 /* font.h -- Interface definition for font handling.
2 Copyright (C) 2006 Free Software Foundation, Inc.
3 Copyright (C) 2006
4 National Institute of Advanced Industrial Science and Technology (AIST)
5 Registration Number H13PRO009
6
7 This file is part of GNU Emacs.
8
9 GNU Emacs is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
12 any later version.
13
14 GNU Emacs is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with GNU Emacs; see the file COPYING. If not, write to
21 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
23
24 #ifndef EMACS_FONT_H
25 #define EMACS_FONT_H
26
27 #include "ccl.h"
28
29 /* We have three types of Lisp objects related to font.
30
31 FONT-SPEC
32
33 Vector (length FONT_SPEC_MAX) of font properties. Some
34 properties can be left unspecified (i.e. nil). Emacs asks
35 font-drivers to find a font by FONT-SPEC. A fontset entry
36 specifies requisite properties whereas a face specifies just
37 preferable properties. This object is fully modifiable by
38 Lisp.
39
40 FONT-ENTITY
41
42 Vector (length FONT_ENTITY_MAX) of fully specified font
43 properties that a font-driver returns upon a request of
44 FONT-SPEC.
45
46 Note: Only the method `list' of a font-driver can create this
47 object, and should never be modified by Lisp. In that sense,
48 it may be cleaner to implement it as a Lisp object of a new
49 type (e.g. struct Lisp_Font).
50
51 FONT-OBJECT
52
53 Lisp object of type Lisp_Misc_Save_Value encapsulating a
54 pointer to "struct font". This corresponds to an opened font.
55
56 Note: The note for FONT-ENTITY also applies to this.
57 */
58
59
60 struct font_driver;
61 struct font;
62
63 /* An enumerator for each font property. This is used as an index to
64 the vector of FONT-SPEC and FONT-ENTITY.
65
66 Note: The order is important and should not be changed. */
67
68 enum font_property_index
69 {
70 /* FONT-TYPE is a symbol indicating a font backend; currently `x',
71 `xft', `ftx', `freetype' are available. For windows, we need
72 `bdf' and `windows'. For Mac OS X, we need `atm'. */
73 FONT_TYPE_INDEX,
74
75 /* FONT-FOUNDRY is a foundry name (symbol). */
76 FONT_FOUNDRY_INDEX,
77
78 /* FONT-FAMILY is a family name (symbol). */
79 FONT_FAMILY_INDEX,
80
81 /* FONT-ADSTYLE is an additional style name (symbol). */
82 FONT_ADSTYLE_INDEX,
83
84 /* FONT-REGISTRY is a combination of a charset-registry and
85 charset0encoding name (symbol). */
86 FONT_REGISTRY_INDEX,
87
88 /* FONT-WEIGHT is a numeric value of weight (e.g. medium, bold) of
89 the font. The value is what defined by FC_WEIGHT_* in
90 fontconfig. */
91 FONT_WEIGHT_INDEX,
92
93 /* FONT-SLANT is a numeric value of slant (e.g. r, i, o) of the
94 font. The value is what defined by FC_SLANT_* in
95 fontconfig plus 100. */
96 FONT_SLANT_INDEX,
97
98 /* FONT-WIDTH is a numeric value of setwidth (e.g. normal,
99 condensed) of the font. The value is what defined by
100 FC_WIDTH_* in fontconfig. */
101 FONT_WIDTH_INDEX,
102
103 /* FONT-SIZE is a size of the font. If integer, it is a pixel
104 size. For a font-spec, the value can be float specifying a
105 point size. For a font-entity, the value can be zero meaning
106 that the font is scalable. */
107 FONT_SIZE_INDEX,
108
109 /* In a font-spec, the value is an alist of extra information of a
110 font such as name, OpenType features, and language coverage.
111 In a font-entity, the value is an extra infomation for
112 identifying a font (font-driver dependent). */
113 FONT_EXTRA_INDEX, /* alist alist */
114
115 /* This value is the length of font-spec vector. */
116 FONT_SPEC_MAX,
117
118 /* The followings are used only for a font-entity. */
119
120 /* Frame on which the font is found. The value is nil if the font
121 can be opend on any frame. */
122 FONT_FRAME_INDEX = FONT_SPEC_MAX,
123
124 /* List of font-objects opened from the font-entity. */
125 FONT_OBJLIST_INDEX,
126
127 /* This value is the length of font-entity vector. */
128 FONT_ENTITY_MAX
129 };
130
131 extern Lisp_Object QCspacing, QCdpi, QCscalable, QCotf, QClanguage, QCscript;
132
133 /* Important character set symbols. */
134 extern Lisp_Object Qiso8859_1, Qiso10646_1, Qunicode_bmp;
135
136 extern Lisp_Object null_string;
137 extern Lisp_Object null_vector;
138
139 /* Structure for an opened font. We can safely cast this structure to
140 "struft font_info". */
141
142 struct font
143 {
144 struct font_info font;
145
146 /* From which font-entity the font is opened. */
147 Lisp_Object entity;
148
149 /* By which pixel size the font is opened. */
150 int pixel_size;
151
152 /* Font-driver for the font. */
153 struct font_driver *driver;
154
155 /* File name of the font, or NULL if the font is not associated with
156 a file. */
157 char *file_name;
158
159 /* Charset to encode a character code into a glyph code of the font.
160 -1 means that the font doesn't require this information to encode
161 a character. */
162 int encoding_charset;
163
164 /* Charset to check if a character code is supported by the font.
165 -1 means that the contents of the font must be looked up to
166 determine it. */
167 int repertory_charset;
168
169 /* Minimum glyph width (in pixels). */
170 int min_width;
171
172 /* Ascent and descent of the font (in pixels). */
173 int ascent, descent;
174
175 /* 1 iff the font is scalable. */
176 int scalable;
177
178 /* There will be more to this structure, but they are private to a
179 font-driver. */
180 };
181
182 enum font_spacing
183 {
184 FONT_SPACING_PROPORTIONAL = 0,
185 FONT_SPACING_DUAL = 90,
186 FONT_SPACING_MONO = 100,
187 FONT_SPACING_CHARCELL = 110
188 };
189
190 struct font_metrics
191 {
192 short lbearing, rbearing, width, ascent, descent;
193 };
194
195 struct font_bitmap
196 {
197 int rows;
198 int width;
199 int pitch;
200 unsigned char *buffer;
201 int left;
202 int top;
203 int advance;
204 void *extra;
205 };
206
207 /* Predicates to check various font-related objects. */
208
209 #define FONTP(x) \
210 (VECTORP (x) && (ASIZE (x) == FONT_SPEC_MAX || ASIZE (x) == FONT_ENTITY_MAX))
211 #define FONT_SPEC_P(x) \
212 (VECTORP (x) && ASIZE (x) == FONT_SPEC_MAX)
213 #define FONT_ENTITY_P(x) \
214 (VECTORP (x) && ASIZE (x) == FONT_ENTITY_MAX)
215 #define FONT_OBJECT_P(x) \
216 (XTYPE (x) == Lisp_Misc && XMISCTYPE (x) == Lisp_Misc_Save_Value)
217
218
219 /* Check macros for various font-related objects. */
220
221 #define CHECK_FONT(x) \
222 do { if (! FONTP (x)) x = wrong_type_argument (Qfont, x); } while (0)
223 #define CHECK_FONT_SPEC(x) \
224 do { if (! FONT_SPEC_P (x)) x = wrong_type_argument (Qfont, x); } while (0)
225 #define CHECK_FONT_ENTITY(x) \
226 do { if (! FONT_ENTITY_P (x)) x = wrong_type_argument (Qfont, x); } while (0)
227 #define CHECK_FONT_OBJECT(x) \
228 do { if (! FONT_OBJECT_P (x)) x = wrong_type_argument (Qfont, x); } while (0)
229
230 #define CHECK_FONT_GET_OBJECT(x, font) \
231 do { \
232 if (! FONT_OBJECT_P (x)) x = wrong_type_argument (Qfont, x); \
233 if (! XSAVE_VALUE (x)->pointer) error ("Font already closed"); \
234 font = XSAVE_VALUE (x)->pointer; \
235 } while (0)
236
237 /* Ignore the difference of font pixel sizes less than or equal to
238 this value. */
239 #define FONT_PIXEL_SIZE_QUANTUM 1
240
241 struct face;
242 struct composition;
243
244 /* Macros for lispy glyph-string. */
245 #define LGSTRING_FONT(lgs) AREF (AREF ((lgs), 0), 0)
246 #define LGSTRING_LBEARING(lgs) AREF (AREF ((lgs), 0), 1)
247 #define LGSTRING_RBEARING(lgs) AREF (AREF ((lgs), 0), 2)
248 #define LGSTRING_WIDTH(lgs) AREF (AREF ((lgs), 0), 3)
249 #define LGSTRING_ASCENT(lgs) AREF (AREF ((lgs), 0), 4)
250 #define LGSTRING_DESCENT(lgs) AREF (AREF ((lgs), 0), 5)
251 #define LGSTRING_SET_FONT(lgs, val) ASET (AREF ((lgs), 0), 0, (val))
252 #define LGSTRING_SET_LBEARING(lgs, val) ASET (AREF ((lgs), 0), 1, (val))
253 #define LGSTRING_SET_RBEARING(lgs, val) ASET (AREF ((lgs), 0), 2, (val))
254 #define LGSTRING_SET_WIDTH(lgs, val) ASET (AREF ((lgs), 0), 3, (val))
255 #define LGSTRING_SET_ASCENT(lgs, val) ASET (AREF ((lgs), 0), 4, (val))
256 #define LGSTRING_SET_DESCENT(lgs, val) ASET (AREF ((lgs), 0), 5, (val))
257
258 #define LGSTRING_LENGTH(lgs) (ASIZE ((lgs)) - 1)
259 #define LGSTRING_GLYPH(lgs, idx) AREF ((lgs), (idx) + 1)
260
261 #define LGLYPH_FROM(g) AREF ((g), 0)
262 #define LGLYPH_TO(g) AREF ((g), 1)
263 #define LGLYPH_CHAR(g) AREF ((g), 2)
264 #define LGLYPH_CODE(g) AREF ((g), 3)
265 #define LGLYPH_WIDTH(g) AREF ((g), 4)
266 #define LGLYPH_ADJUSTMENT(g) AREF ((g), 5)
267 #define LGLYPH_SET_FROM(g, val) ASET ((g), 0, (val))
268 #define LGLYPH_SET_TO(g, val) ASET ((g), 1, (val))
269 #define LGLYPH_SET_CHAR(g, val) ASET ((g), 2, (val))
270 #define LGLYPH_SET_CODE(g, val) ASET ((g), 3, (val))
271 #define LGLYPH_SET_WIDTH(g, val) ASET ((g), 4, (val))
272 #define LGLYPH_SET_ADJUSTMENT(g, val) ASET ((g), 5, (val))
273
274 #define LGLYPH_XOFF(g) (VECTORP (LGLYPH_ADJUSTMENT (g)) \
275 ? XINT (AREF (LGLYPH_ADJUSTMENT (g), 0)) : 0)
276 #define LGLYPH_YOFF(g) (VECTORP (LGLYPH_ADJUSTMENT (g)) \
277 ? XINT (AREF (LGLYPH_ADJUSTMENT (g), 1)) : 0)
278 #define LGLYPH_WADJUST(g) (VECTORP (LGLYPH_ADJUSTMENT (g)) \
279 ? XINT (AREF (LGLYPH_ADJUSTMENT (g), 2)) : 0)
280
281 #define FONT_INVALID_CODE 0xFFFFFFFF
282
283 /* Font driver. Members specified as "optional" can be NULL. */
284
285 struct font_driver
286 {
287 /* Symbol indicating the type of the font-driver. */
288 Lisp_Object type;
289
290 /* Return a cache of font-entities on FRAME. The cache must be a
291 cons whose cdr part is the actual cache area. */
292 Lisp_Object (*get_cache) P_ ((Lisp_Object frame));
293
294 /* List fonts exactly matching with FONT_SPEC on FRAME. The value
295 is a vector of font-entities. This is the sole API that
296 allocates font-entities. */
297 Lisp_Object (*list) P_ ((Lisp_Object frame, Lisp_Object font_spec));
298
299 /* Return a font entity most closely maching with FONT_SPEC on
300 FRAME. The closeness is detemined by the font backend, thus
301 `face-font-selection-order' is ignored here. */
302 Lisp_Object (*match) P_ ((Lisp_Object frame, Lisp_Object font_spec));
303
304 /* Optional.
305 List available families. The value is a list of family names
306 (symbols). */
307 Lisp_Object (*list_family) P_ ((Lisp_Object frame));
308
309 /* Optional (if FONT_EXTRA_INDEX is not Lisp_Save_Value).
310 Free FONT_EXTRA_INDEX field of FONT_ENTITY. */
311 void (*free_entity) P_ ((Lisp_Object font_entity));
312
313 /* Open a font specified by FONT_ENTITY on frame F. If the font is
314 scalable, open it with PIXEL_SIZE. */
315 struct font *(*open) P_ ((FRAME_PTR f, Lisp_Object font_entity,
316 int pixel_size));
317
318 /* Close FONT on frame F. */
319 void (*close) P_ ((FRAME_PTR f, struct font *font));
320
321 /* Optional (if FACE->extra is not used).
322 Prepare FACE for displaying characters by FONT on frame F by
323 storing some data in FACE->extra. If successful, return 0.
324 Otherwise, return -1. */
325 int (*prepare_face) P_ ((FRAME_PTR f, struct face *face));
326
327 /* Optional.
328 Done FACE for displaying characters by FACE->font on frame F. */
329 void (*done_face) P_ ((FRAME_PTR f, struct face *face));
330
331 /* Optional.
332 If FONT_ENTITY has a glyph for character C (Unicode code point),
333 return 1. If not, return 0. If a font must be opened to check
334 it, return -1. */
335 int (*has_char) P_ ((Lisp_Object entity, int c));
336
337 /* Return a glyph code of FONT for characer C (Unicode code point).
338 If FONT doesn't have such a glyph, return FONT_INVALID_CODE. */
339 unsigned (*encode_char) P_ ((struct font *font, int c));
340
341 /* Perform the size computation of glyphs of FONT and fillin members
342 of METRICS. The glyphs are specified by their glyph codes in
343 CODE (length NGLYPHS). */
344 int (*text_extents) P_ ((struct font *font,
345 unsigned *code, int nglyphs,
346 struct font_metrics *metrics));
347
348 /* Optional.
349 Draw glyphs between FROM and TO of S->char2b at (X Y) pixel
350 position of frame F with S->FACE and S->GC. If WITH_BACKGROUND
351 is nonzero, fill the background in advance. It is assured that
352 WITH_BACKGROUND is zero when (FROM > 0 || TO < S->nchars). */
353 int (*draw) P_ ((struct glyph_string *s, int from, int to,
354 int x, int y, int with_background));
355
356 /* Optional.
357 Store bitmap data for glyph-code CODE of FONT in BITMAP. It is
358 intended that this method is callled from the other font-driver
359 for actual drawing. */
360 int (*get_bitmap) P_ ((struct font *font, unsigned code,
361 struct font_bitmap *bitmap,
362 int bits_per_pixel));
363
364 /* Optional.
365 Free bitmap data in BITMAP. */
366 void (*free_bitmap) P_ ((struct font *font, struct font_bitmap *bitmap));
367
368 /* Optional.
369 Return an outline data for glyph-code CODE of FONT. The format
370 of the outline data depends on the font-driver. */
371 void *(*get_outline) P_ ((struct font *font, unsigned code));
372
373 /* Optional.
374 Free OUTLINE (that is obtained by the above method). */
375 void (*free_outline) P_ ((struct font *font, void *outline));
376
377 /* Optional.
378 Get coordinates of the INDEXth anchor point of the glyph whose
379 code is CODE. Store the coordinates in *X and *Y. Return 0 if
380 the operations was successfull. Otherwise return -1. */
381 int (*anchor_point) P_ ((struct font *font, unsigned code, int index,
382 int *x, int *y));
383
384 /* Optional.
385 Return a list describing which scripts/languages FONT
386 supports by which GSUB/GPOS features of OpenType tables. */
387 Lisp_Object (*otf_capability) P_ ((struct font *font));
388
389 /* Optional.
390 Drive FONT's OTF GSUB features according to GSUB_SPEC.
391
392 GSUB_SPEC is in this format (all elements are symbols):
393 (SCRIPT LANGSYS GSUB-FEATURE ...)
394 If one of GSUB-FEATURE is nil, apply all gsub features except for
395 already applied and listed later. For instance, if the font has
396 GSUB features nukt, haln, rphf, blwf, and half,
397 (deva nil nukt haln nil rphf)
398 applies nukt and haln in this order, then applies blwf and half
399 in the order apearing in the font. The features are of the
400 default langsys of `deva' script.
401
402 This method applies the specified features to the codes in the
403 elements of GSTRING-IN (between FROMth and TOth). The output
404 codes are stored in GSTRING-OUT at the IDXth element and the
405 following elements.
406
407 Return the number of output codes. If none of the features are
408 applicable to the input data, return 0. If GSTRING-OUT is too
409 short, return -1. */
410 int (*otf_gsub) P_ ((struct font *font, Lisp_Object gsub_spec,
411 Lisp_Object gstring_in, int from, int to,
412 Lisp_Object gstring_out, int idx, int alternate_subst));
413
414 /* Optional.
415 Drive FONT's OTF GPOS features according to GPOS_SPEC.
416
417 GPOS_SPEC is in this format (all elements are symbols):
418 (SCRIPT LANGSYS GPOS-FEATURE ...)
419 The meaning is the same as GSUB_SPEC above.
420
421 This method applies the specified features to the codes in the
422 elements of GSTRING (between FROMth and TOth). The resulting
423 positioning information (x-offset and y-offset) is stored in the
424 slots of the elements.
425
426 Return 1 if at least one glyph has nonzero x-offset or y-offset.
427 Otherwise return 0. */
428 int (*otf_gpos) P_ ((struct font *font, Lisp_Object gpos_spec,
429 Lisp_Object gstring, int from, int to));
430 };
431
432
433 struct font_driver_list
434 {
435 /* 1 iff this driver is currently used. */
436 int on;
437 struct font_driver *driver;
438 struct font_driver_list *next;
439 };
440
441 extern int enable_font_backend;
442
443 EXFUN (Ffont_spec, MANY);
444 EXFUN (Flist_fonts, 4);
445 EXFUN (Fclear_font_cache, 0);
446
447 extern Lisp_Object font_symbolic_weight P_ ((Lisp_Object font));
448 extern Lisp_Object font_symbolic_slant P_ ((Lisp_Object font));
449 extern Lisp_Object font_symbolic_width P_ ((Lisp_Object font));
450
451 extern int font_match_p P_ ((Lisp_Object spec, Lisp_Object entity));
452
453 extern Lisp_Object font_find_object P_ ((struct font *font));
454 extern Lisp_Object font_get_name P_ ((Lisp_Object font_object));
455 extern Lisp_Object font_get_spec P_ ((Lisp_Object font_object));
456 extern Lisp_Object font_get_frame P_ ((Lisp_Object font_object));
457 extern int font_has_char P_ ((FRAME_PTR, Lisp_Object, int));
458 extern unsigned font_encode_char P_ ((Lisp_Object, int));
459
460 extern int font_set_lface_from_name P_ ((FRAME_PTR f,
461 Lisp_Object lface,
462 Lisp_Object fontname,
463 int force_p, int may_fail_p));
464 extern Lisp_Object font_find_for_lface P_ ((FRAME_PTR f, Lisp_Object *lface,
465 Lisp_Object spec));
466 extern Lisp_Object font_open_for_lface P_ ((FRAME_PTR f, Lisp_Object *lface,
467 Lisp_Object entity));
468 extern void font_load_for_face P_ ((FRAME_PTR f, struct face *face));
469 extern void font_prepare_for_face P_ ((FRAME_PTR f, struct face *face));
470 extern Lisp_Object font_open_by_name P_ ((FRAME_PTR f, char *name));
471 extern void font_close_object (FRAME_PTR f, Lisp_Object font_object);
472
473 extern Lisp_Object intern_downcase P_ ((char *str, int len));
474 extern void font_update_sort_order P_ ((int *order));
475
476 extern void font_merge_old_spec P_ ((Lisp_Object name, Lisp_Object family,
477 Lisp_Object registry, Lisp_Object spec));
478
479
480 extern int font_parse_xlfd P_ ((char *name, Lisp_Object font));
481 extern int font_unparse_xlfd P_ ((Lisp_Object font, int pixel_size,
482 char *name, int bytes));
483 extern int font_parse_fcname P_ ((char *name, Lisp_Object font));
484 extern int font_unparse_fcname P_ ((Lisp_Object font, int pixel_size,
485 char *name, int bytes));
486 extern void register_font_driver P_ ((struct font_driver *driver, FRAME_PTR f));
487 extern void free_font_driver_list P_ ((FRAME_PTR f));
488 extern Lisp_Object font_update_drivers P_ ((FRAME_PTR f, Lisp_Object list));
489 extern Lisp_Object font_at P_ ((int c, EMACS_INT pos, struct face *face,
490 struct window *w, Lisp_Object object));
491
492 extern struct font *font_prepare_composition P_ ((struct composition *cmp));
493
494
495 #ifdef HAVE_LIBOTF
496 /* This can be used as `otf_capability' method of a font-driver. */
497 extern Lisp_Object font_otf_capability P_ ((struct font *font));
498 /* This can be used as `otf_gsub' method of a font-driver. */
499 extern int font_otf_gsub P_ ((struct font *font, Lisp_Object gsub_spec,
500 Lisp_Object gstring_in, int from, int to,
501 Lisp_Object gstring_out, int idx,
502 int alternate_subst));
503 /* This can be used as `otf_gpos' method of a font-driver. */
504 extern int font_otf_gpos P_ ((struct font *font, Lisp_Object gpos_spec,
505 Lisp_Object gstring, int from, int to));
506 #endif /* HAVE_LIBOTF */
507
508 #ifdef HAVE_FREETYPE
509 extern struct font_driver ftfont_driver;
510 #endif /* HAVE_FREETYPE */
511 #ifdef HAVE_X_WINDOWS
512 extern struct font_driver xfont_driver;
513 extern struct font_driver ftxfont_driver;
514 #ifdef HAVE_XFT
515 extern struct font_driver xftfont_driver;
516 #endif /* HAVE_XFT */
517 #endif /* HAVE_X_WINDOWS */
518 #ifdef WINDOWSNT
519 extern struct font_driver w32font_driver;
520 #endif /* WINDOWSNT */
521 #ifdef MAC_OS
522 extern struct font_driver atmfont_driver;
523 #endif /* MAC_OS */
524
525 #endif /* not EMACS_FONT_H */
526
527 /* arch-tag: 3b7260c3-5bec-4d6b-a0db-95c1b431b1a2
528 (do not change this comment) */