src/xdisp.c (single_display_spec_string): Correct a FIXME comment.
[emacs.git] / src / font.h
blob4b3ceed1dd39d7c2e6897a78308fc0d738d67619
1 /* font.h -- Interface definition for font handling.
2 Copyright (C) 2006-2011 Free Software Foundation, Inc.
3 Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
4 National Institute of Advanced Industrial Science and Technology (AIST)
5 Registration Number H13PRO009
7 This file is part of GNU Emacs.
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 3 of the License, or
12 (at your option) any later version.
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.
19 You should have received a copy of the GNU General Public License
20 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
22 #ifndef EMACS_FONT_H
23 #define EMACS_FONT_H
25 #include "ccl.h"
27 /* We have three types of Lisp objects related to font.
29 FONT-SPEC
31 Pseudo vector (length FONT_SPEC_MAX) of font properties. Some
32 properties can be left unspecified (i.e. nil). Emacs asks
33 font-drivers to find a font by FONT-SPEC. A fontset entry
34 specifies requisite properties whereas a face specifies just
35 preferable properties.
37 FONT-ENTITY
39 Pseudo vector (length FONT_ENTITY_MAX) of fully instanciated
40 font properties that a font-driver returns upon a request of
41 FONT-SPEC.
43 Note: Only the method `list' and `match' of a font-driver can
44 create this object, and should never be modified by Lisp.
46 FONT-OBJECT
48 Pseudo vector (length FONT_OBJECT_MAX) of a opend font.
50 Lisp object encapsulating "struct font". This corresponds to
51 an opened font.
53 Note: Only the method `open' of a font-driver can create this
54 object, and should never be modified by Lisp. */
56 extern Lisp_Object Qfont_spec, Qfont_entity, Qfont_object;
59 struct font_driver;
60 struct font;
61 struct glyph_string;
63 /* An enumerator for each font property. This is used as an index to
64 the vector of FONT-SPEC and FONT-ENTITY.
66 Note: The order is important and should not be changed. */
68 enum font_property_index
70 /* FONT-TYPE is a symbol indicating a font backend; currently `x',
71 `xft', `ftx' are available on X, `uniscribe' and `gdi' on
72 Windows, and `ns' under Cocoa / GNUstep. */
73 FONT_TYPE_INDEX,
75 /* FONT-FOUNDRY is a foundry name (symbol). */
76 FONT_FOUNDRY_INDEX,
78 /* FONT-FAMILY is a family name (symbol). */
79 FONT_FAMILY_INDEX,
81 /* FONT-ADSTYLE is an additional style name (symbol). */
82 FONT_ADSTYLE_INDEX,
84 /* FONT-REGISTRY is a combination of a charset-registry and
85 charset-encoding name (symbol). */
86 FONT_REGISTRY_INDEX,
88 /* FONT-WEIGHT is a numeric value of weight (e.g. medium, bold) of
89 the font. The lowest 8-bit is an index determining the
90 symbolic name, and the higher bits is the actual numeric value
91 defined in `font-weight-table'. */
92 FONT_WEIGHT_INDEX,
94 /* FONT-SLANT is a numeric value of slant (e.g. r, i, o) of the
95 font. The lowest 8-bit is an index determining the symbolic
96 name, and the higher bits is the actual numeric value defined
97 in `font-slant-table'. */
98 FONT_SLANT_INDEX,
100 /* FONT-WIDTH is a numeric value of setwidth (e.g. normal) of the
101 font. The lowest 8-bit is an index determining the symbolic
102 name, and the higher bits is the actual numeric value defined
103 `font-width-table'. */
104 FONT_WIDTH_INDEX,
106 /* FONT-SIZE is a size of the font. If integer, it is a pixel
107 size. For a font-spec, the value can be float specifying a
108 point size. The value zero means that the font is
109 scalable. */
110 FONT_SIZE_INDEX,
112 /* FONT-DPI is a resolution (dot per inch) for which the font is
113 designed. */
114 FONT_DPI_INDEX,
116 /* FONT-SPACING is a spacing (mono, proportional, charcell) of the
117 font (integer; one of enum font_spacing). */
118 FONT_SPACING_INDEX,
120 /* FONT-AVGWIDTH is an average width (1/10 pixel unit) of the
121 font. */
122 FONT_AVGWIDTH_INDEX,
124 #if 0
125 /* The following two members are to substitute for the above 6
126 members (FONT_WEIGHT_INDEX to FONT_AVGWIDTH_INDEX excluding
127 FONT_SIZE_INDEX) if it is found that font-entities consumes too
128 much memory. */
130 /* FONT-STYLE is a 24-bit integer containing indices for
131 style-related properties WEIGHT, SLANT, and WIDTH. The lowest
132 8-bit is an indice to the weight table AREF (font_style_table,
133 0), the next 8-bit is an indice to the slant table AREF
134 (font_style_table, 1), the highest 8-bit is an indice to the
135 slant table AREF (font_style_table, 2). The indice 0 indicates
136 that the corresponding style is not specified. This way, we
137 can represent at most 255 different names for each style, which
138 is surely sufficient. */
139 FONT_STYLE_INDEX,
141 /* FONT-METRICS is a 27-bit integer containing metrics-related
142 properties DPI, AVGWIDTH, SPACING. The lowest 12-bit is for
143 DPI, the next 12-bit is for AVGWIDTH, the highest 3-bit is for
144 SPACING. In each bit field, the highest bit indicates that the
145 corresponding value is set or not. This way, we can represent
146 DPI by 11-bit (0 to 2047), AVGWIDTH by 11-bit (0 to 2047),
147 SPACING by 3-bit (0 for proportional, 1 for dual, 2 for mono, 3
148 for charcell), which is surely sufficient. */
149 FONT_METRICS_INDEX,
150 #endif
152 /* In a font-spec, the value is an alist of extra information of a
153 font such as name, OpenType features, and language coverage.
154 In addition, in a font-entity, the value may contain a pair
155 (font-entity . INFO) where INFO is extra information to identify
156 a font (font-driver dependent). */
157 FONT_EXTRA_INDEX, /* alist alist */
159 /* This value is the length of font-spec vector. */
160 FONT_SPEC_MAX,
162 /* The followings are used only for a font-entity and a font-object. */
164 /* List of font-objects opened from the font-entity. */
165 FONT_OBJLIST_INDEX = FONT_SPEC_MAX,
167 /* Font-entity from which the font-object is opened. */
168 FONT_ENTITY_INDEX = FONT_SPEC_MAX,
170 /* This value is the length of font-entity vector. */
171 FONT_ENTITY_MAX,
173 /* The followings are used only for a font-object. */
175 /* XLFD name of the font (string). */
176 FONT_NAME_INDEX = FONT_ENTITY_MAX,
178 /* Full name of the font (string). It is the name extracted from
179 the opend font, and may be different from the above. It may be
180 nil if the opened font doesn't give a name. */
181 FONT_FULLNAME_INDEX,
183 /* File name of the font or nil if a file associated with the font
184 is not available. */
185 FONT_FILE_INDEX,
187 /* Format of the font (symbol) or nil if unknown. */
188 FONT_FORMAT_INDEX,
190 /* This value is the length of font-object vector. */
191 FONT_OBJECT_MAX
194 /* Return the numeric weight value of FONT. */
195 #define FONT_WEIGHT_NUMERIC(font) \
196 (INTEGERP (AREF ((font), FONT_WEIGHT_INDEX)) \
197 ? (XINT (AREF ((font), FONT_WEIGHT_INDEX)) >> 8) : -1)
198 /* Return the numeric slant value of FONT. */
199 #define FONT_SLANT_NUMERIC(font) \
200 (INTEGERP (AREF ((font), FONT_SLANT_INDEX)) \
201 ? (XINT (AREF ((font), FONT_SLANT_INDEX)) >> 8) : -1)
202 /* Return the numeric width value of FONT. */
203 #define FONT_WIDTH_NUMERIC(font) \
204 (INTEGERP (AREF ((font), FONT_WIDTH_INDEX)) \
205 ? (XINT (AREF ((font), FONT_WIDTH_INDEX)) >> 8) : -1)
206 /* Return the symbolic weight value of FONT. */
207 #define FONT_WEIGHT_SYMBOLIC(font) \
208 font_style_symbolic (font, FONT_WEIGHT_INDEX, 0)
209 /* Return the symbolic slant value of FONT. */
210 #define FONT_SLANT_SYMBOLIC(font) \
211 font_style_symbolic (font, FONT_SLANT_INDEX, 0)
212 /* Return the symbolic width value of FONT. */
213 #define FONT_WIDTH_SYMBOLIC(font) \
214 font_style_symbolic (font, FONT_WIDTH_INDEX, 0)
215 /* Return the face-weight corresponding to the weight of FONT. */
216 #define FONT_WEIGHT_FOR_FACE(font) \
217 font_style_symbolic (font, FONT_WEIGHT_INDEX, 1)
218 /* Return the face-slant corresponding to the slant of FONT. */
219 #define FONT_SLANT_FOR_FACE(font) \
220 font_style_symbolic (font, FONT_SLANT_INDEX, 1)
221 /* Return the face-swidth corresponding to the slant of FONT. */
222 #define FONT_WIDTH_FOR_FACE(font) \
223 font_style_symbolic (font, FONT_WIDTH_INDEX, 1)
225 /* Return the numeric weight value corresponding ot the symbol NAME. */
226 #define FONT_WEIGHT_NAME_NUMERIC(name) \
227 (font_style_to_value (FONT_WEIGHT_INDEX, (name), 0) >> 8)
228 /* Return the numeric slant value corresponding ot the symbol NAME. */
229 #define FONT_SLANT_NAME_NUMERIC(name) \
230 (font_style_to_value (FONT_SLANT_INDEX, (name), 0) >> 8)
231 /* Return the numeric width value corresponding ot the symbol NAME. */
232 #define FONT_WIDTH_NAME_NUMERIC(name) \
233 (font_style_to_value (FONT_WIDTH_INDEX, (name), 0) >> 8)
235 /* Set the font property PROP of FONT to VAL. PROP is one of
236 style-related font property index (FONT_WEIGHT/SLANT/WIDTH_INDEX).
237 VAL (integer or symbol) is the numeric or symbolic style value. */
238 #define FONT_SET_STYLE(font, prop, val) \
239 ASET ((font), prop, make_number (font_style_to_value (prop, val, 1)))
241 extern Lisp_Object QCspacing, QCdpi, QCscalable, QCotf, QClang, QCscript;
242 extern Lisp_Object QCavgwidth, QCantialias, QCfont_entity;
243 extern Lisp_Object Qp;
246 /* Important character set symbols. */
247 extern Lisp_Object Qascii_0;
248 extern Lisp_Object Qiso8859_1, Qiso10646_1, Qunicode_bmp, Qunicode_sip;
250 /* Special ADSTYLE properties to avoid fonts used for Latin characters. */
251 extern Lisp_Object Qja, Qko;
253 /* Structure for a font-spec. */
255 struct font_spec
257 struct vectorlike_header header;
258 Lisp_Object props[FONT_SPEC_MAX];
261 /* Structure for a font-entity. */
263 struct font_entity
265 struct vectorlike_header header;
266 Lisp_Object props[FONT_ENTITY_MAX];
269 /* A value which may appear in the member `encoding' of struct font
270 indicating that a font itself doesn't tell which encoding to be
271 used. */
272 #define FONT_ENCODING_NOT_DECIDED 255
274 /* Structure for a font-object. */
276 struct font
278 struct vectorlike_header header;
280 /* All Lisp_Object components must come first.
281 That ensures they are all aligned normally. */
283 Lisp_Object props[FONT_OBJECT_MAX];
285 /* Beyond here, there should be no more Lisp_Object components. */
287 /* Maximum bound width over all existing characters of the font. On
288 X window, this is same as (font->max_bounds.width). */
289 int max_width;
291 /* By which pixel size the font is opened. */
292 int pixel_size;
294 /* Height of the font. On X window, this is the same as
295 (font->ascent + font->descent). */
296 int height;
298 /* Width of the space glyph of the font. If the font doesn't have a
299 SPACE glyph, the value is 0. */
300 int space_width;
302 /* Average width of glyphs in the font. If the font itself doesn't
303 have that information but has glyphs of ASCII character, the
304 value is the average with of those glyphs. Otherwise, the value
305 is 0. */
306 int average_width;
308 /* Minimum glyph width (in pixels). */
309 int min_width;
311 /* Ascent and descent of the font (in pixels). */
312 int ascent, descent;
314 /* Vertical pixel width of the underline. If is zero if that
315 information is not in the font. */
316 int underline_thickness;
318 /* Vertical pixel position (relative to the baseline) of the
319 underline. If it is positive, it is below the baseline. It is
320 negative if that information is not in the font. */
321 int underline_position;
323 /* 1 if `vertical-centering-font-regexp' matches this font name.
324 In this case, we render characters at vartical center positions
325 of lines. */
326 int vertical_centering;
328 /* Encoding type of the font. The value is one of
329 0, 1, 2, or 3:
330 0: code points 0x20..0x7F or 0x2020..0x7F7F are used
331 1: code points 0xA0..0xFF or 0xA0A0..0xFFFF are used
332 2: code points 0x20A0..0x7FFF are used
333 3: code points 0xA020..0xFF7F are used
334 If the member `font_encoder' is not NULL, this member is ignored. */
335 unsigned char encoding_type;
337 /* The baseline position of a font is normally `ascent' value of the
338 font. However, there exists many fonts which don't set `ascent'
339 an appropriate value to be used as baseline position. This is
340 typical in such ASCII fonts which are designed to be used with
341 Chinese, Japanese, Korean characters. When we use mixture of
342 such fonts and normal fonts (having correct `ascent' value), a
343 display line gets very ugly. Since we have no way to fix it
344 automatically, it is users responsibility to supply well designed
345 fonts or correct `ascent' value of fonts. But, the latter
346 requires heavy work (modifying all bitmap data in BDF files).
347 So, Emacs accepts a private font property
348 `_MULE_BASELINE_OFFSET'. If a font has this property, we
349 calculate the baseline position by subtracting the value from
350 `ascent'. In other words, the value indicates how many bits
351 higher we should draw a character of the font than normal ASCII
352 text for a better looking.
354 We also have to consider the fact that the concept of `baseline'
355 differs among scripts to which each character belongs. For
356 instance, baseline should be at the bottom most position of all
357 glyphs for Chinese, Japanese, and Korean. But, many of existing
358 fonts for those characters doesn't have correct `ascent' values
359 because they are designed to be used with ASCII fonts. To
360 display characters of different language on the same line, the
361 best way will be to arrange them in the middle of the line. So,
362 in such a case, again, we utilize the font property
363 `_MULE_BASELINE_OFFSET'. If the value is larger than `ascent' we
364 calculate baseline so that a character is arranged in the middle
365 of a line. */
366 int baseline_offset;
368 /* Non zero means a character should be composed at a position
369 relative to the height (or depth) of previous glyphs in the
370 following cases:
371 (1) The bottom of the character is higher than this value. In
372 this case, the character is drawn above the previous glyphs.
373 (2) The top of the character is lower than 0 (i.e. baseline
374 height). In this case, the character is drawn beneath the
375 previous glyphs.
377 This value is taken from a private font property
378 `_MULE_RELATIVE_COMPOSE' which is introduced by Emacs. */
379 int relative_compose;
381 /* Non zero means an ascent value to be used for a character
382 registered in char-table `use-default-ascent'. */
383 int default_ascent;
385 /* CCL program to calculate code points of the font. */
386 struct ccl_program *font_encoder;
388 /* Font-driver for the font. */
389 struct font_driver *driver;
391 /* Charset to encode a character code into a glyph code of the font.
392 -1 means that the font doesn't require this information to encode
393 a character. */
394 int encoding_charset;
396 /* Charset to check if a character code is supported by the font.
397 -1 means that the contents of the font must be looked up to
398 determine it. */
399 int repertory_charset;
401 /* There will be more to this structure, but they are private to a
402 font-driver. */
405 enum font_spacing
407 FONT_SPACING_PROPORTIONAL = 0,
408 FONT_SPACING_DUAL = 90,
409 FONT_SPACING_MONO = 100,
410 FONT_SPACING_CHARCELL = 110
413 struct font_metrics
415 short lbearing, rbearing, width, ascent, descent;
418 struct font_bitmap
420 int bits_per_pixel;
421 int rows;
422 int width;
423 int pitch;
424 unsigned char *buffer;
425 int left;
426 int top;
427 int advance;
428 void *extra;
431 /* Predicates to check various font-related objects. */
433 /* 1 iff X is one of font-spec, font-entity, and font-object. */
434 #define FONTP(x) PSEUDOVECTORP (x, PVEC_FONT)
435 /* 1 iff X is font-spec. */
436 #define FONT_SPEC_P(x) \
437 (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_SPEC_MAX)
438 /* 1 iff X is font-entity. */
439 #define FONT_ENTITY_P(x) \
440 (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_ENTITY_MAX)
441 /* 1 iff X is font-object. */
442 #define FONT_OBJECT_P(x) \
443 (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_OBJECT_MAX)
445 /* 1 iff ENTITY can't be loaded. */
446 #define FONT_ENTITY_NOT_LOADABLE(entity) \
447 EQ (AREF (entity, FONT_OBJLIST_INDEX), Qt)
449 /* Flag ENTITY not loadable. */
450 #define FONT_ENTITY_SET_NOT_LOADABLE(entity) \
451 ASET (entity, FONT_OBJLIST_INDEX, Qt)
454 /* Check macros for various font-related objects. */
456 #define CHECK_FONT(x) \
457 do { if (! FONTP (x)) wrong_type_argument (Qfont, x); } while (0)
458 #define CHECK_FONT_SPEC(x) \
459 do { if (! FONT_SPEC_P (x)) wrong_type_argument (Qfont_spec, x); } while (0)
460 #define CHECK_FONT_ENTITY(x) \
461 do { if (! FONT_ENTITY_P (x)) wrong_type_argument (Qfont_entity, x); } while (0)
462 #define CHECK_FONT_OBJECT(x) \
463 do { if (! FONT_OBJECT_P (x)) wrong_type_argument (Qfont_object, x); } while (0)
465 #define CHECK_FONT_GET_OBJECT(x, font) \
466 do { \
467 CHECK_FONT_OBJECT (x); \
468 font = XFONT_OBJECT (x); \
469 } while (0)
471 #define XFONT_SPEC(p) \
472 (eassert (FONT_SPEC_P(p)), (struct font_spec *) XPNTR (p))
473 #define XFONT_ENTITY(p) \
474 (eassert (FONT_ENTITY_P(p)), (struct font_entity *) XPNTR (p))
475 #define XFONT_OBJECT(p) \
476 (eassert (FONT_OBJECT_P(p)), (struct font *) XPNTR (p))
477 #define XSETFONT(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_FONT))
479 /* Number of pt per inch (from the TeXbook). */
480 #define PT_PER_INCH 72.27
482 /* Return a pixel size (integer) corresponding to POINT size (double)
483 on resolution DPI. */
484 #define POINT_TO_PIXEL(POINT, DPI) ((POINT) * (DPI) / PT_PER_INCH + 0.5)
486 /* Return a point size corresponding to POINT size (integer)
487 on resolution DPI. Note that though point size is a double, we expect
488 it to be rounded to an int, so we add 0.5 here. If the desired value
489 is tenths of points (as in xfld specs), then the pixel size should
490 be multiplied BEFORE the conversion to avoid magnifying the error. */
491 #define PIXEL_TO_POINT(PIXEL, DPI) ((PIXEL) * PT_PER_INCH / (DPI) + 0.5)
493 /* Ignore the difference of font pixel sizes less than or equal to
494 this value. */
495 #define FONT_PIXEL_SIZE_QUANTUM 1
497 struct face;
499 #define FONT_INVALID_CODE 0xFFFFFFFF
501 /* Font driver. Members specified as "optional" can be NULL. */
503 struct font_driver
505 /* Symbol indicating the type of the font-driver. */
506 Lisp_Object type;
508 /* 1 iff the font's foundry, family, and adstyle names are case
509 sensitve. */
510 int case_sensitive;
512 /* Return a cache of font-entities on frame F. The cache must be a
513 cons whose cdr part is the actual cache area. */
514 Lisp_Object (*get_cache) (FRAME_PTR F);
516 /* List fonts exactly matching with FONT_SPEC on FRAME. The value
517 is a list of font-entities. The font properties to be considered
518 are: :foundry, :family, :adstyle, :registry, :script, :lang, and
519 :otf. See the function `font-spec' for their meanings. Note
520 that the last three properties are stored in FONT_EXTRA_INDEX
521 slot of FONT_SPEC.
523 The returned value is a list of font-entities. Each font-entity
524 has :type property whose value is the same as the above `type'.
525 It also has these properties if they are available from the
526 corresponding font; :foundry, :family, :adstyle, :registry,
527 :weight, :slant, :width, :size, :dpi, :spacing, :avgwidth. If
528 the font is scalable, :size and :avgwidth must be 0.
530 The `open' method of the same font-backend is called with one of
531 the returned font-entities. If the backend needs additional
532 information to be used in `open' method, this method can add any
533 Lispy value by the property :font-entity to the entities.
535 This and the following `match' are the only APIs that allocate
536 font-entities. */
537 Lisp_Object (*list) (Lisp_Object frame, Lisp_Object font_spec);
539 /* Return a font-entity most closely matching with FONT_SPEC on
540 FRAME. Which font property to consider, and how to calculate the
541 closeness is determined by the font backend, thus
542 `face-font-selection-order' is ignored here.
544 The properties that the font-entity has is the same as `list'
545 method. */
546 Lisp_Object (*match) (Lisp_Object frame, Lisp_Object font_spec);
548 /* Optional.
549 List available families. The value is a list of family names
550 (symbols). */
551 Lisp_Object (*list_family) (Lisp_Object frame);
553 /* Optional (if FONT_EXTRA_INDEX is not Lisp_Save_Value).
554 Free FONT_EXTRA_INDEX field of FONT_ENTITY. */
555 void (*free_entity) (Lisp_Object font_entity);
557 /* Open a font specified by FONT_ENTITY on frame F. If the font is
558 scalable, open it with PIXEL_SIZE. */
559 Lisp_Object (*open) (FRAME_PTR f, Lisp_Object font_entity,
560 int pixel_size);
562 /* Close FONT on frame F. */
563 void (*close) (FRAME_PTR f, struct font *font);
565 /* Optional (if FACE->extra is not used).
566 Prepare FACE for displaying characters by FONT on frame F by
567 storing some data in FACE->extra. If successful, return 0.
568 Otherwise, return -1. */
569 int (*prepare_face) (FRAME_PTR f, struct face *face);
571 /* Optional.
572 Done FACE for displaying characters by FACE->font on frame F. */
573 void (*done_face) (FRAME_PTR f, struct face *face);
575 /* Optional.
576 If FONT (FONT-ENTITY or FONT-OBJECT) has a glyph for character C
577 (Unicode code point), return 1. If not, return 0. If FONT is
578 FONT-ENTITY and it must be opened to check it, return -1. */
579 int (*has_char) (Lisp_Object font, int c);
581 /* Return a glyph code of FONT for character C (Unicode code point).
582 If FONT doesn't have such a glyph, return FONT_INVALID_CODE. */
583 unsigned (*encode_char) (struct font *font, int c);
585 /* Computate the total metrics of the NGLYPHS glyphs specified by
586 the font FONT and the sequence of glyph codes CODE, and store the
587 result in METRICS. */
588 int (*text_extents) (struct font *font,
589 unsigned *code, int nglyphs,
590 struct font_metrics *metrics);
592 /* Optional.
593 Draw glyphs between FROM and TO of S->char2b at (X Y) pixel
594 position of frame F with S->FACE and S->GC. If WITH_BACKGROUND
595 is nonzero, fill the background in advance. It is assured that
596 WITH_BACKGROUND is zero when (FROM > 0 || TO < S->nchars). */
597 int (*draw) (struct glyph_string *s, int from, int to,
598 int x, int y, int with_background);
600 /* Optional.
601 Store bitmap data for glyph-code CODE of FONT in BITMAP. It is
602 intended that this method is callled from the other font-driver
603 for actual drawing. */
604 int (*get_bitmap) (struct font *font, unsigned code,
605 struct font_bitmap *bitmap,
606 int bits_per_pixel);
608 /* Optional.
609 Free bitmap data in BITMAP. */
610 void (*free_bitmap) (struct font *font, struct font_bitmap *bitmap);
612 /* Optional.
613 Return an outline data for glyph-code CODE of FONT. The format
614 of the outline data depends on the font-driver. */
615 void *(*get_outline) (struct font *font, unsigned code);
617 /* Optional.
618 Free OUTLINE (that is obtained by the above method). */
619 void (*free_outline) (struct font *font, void *outline);
621 /* Optional.
622 Get coordinates of the INDEXth anchor point of the glyph whose
623 code is CODE. Store the coordinates in *X and *Y. Return 0 if
624 the operations was successfull. Otherwise return -1. */
625 int (*anchor_point) (struct font *font, unsigned code, int index,
626 int *x, int *y);
628 /* Optional.
629 Return a list describing which scripts/languages FONT
630 supports by which GSUB/GPOS features of OpenType tables. */
631 Lisp_Object (*otf_capability) (struct font *font);
633 /* Optional.
634 Apply FONT's OTF-FEATURES to the glyph string.
636 FEATURES specifies which OTF features to apply in this format:
637 (SCRIPT LANGSYS GSUB-FEATURE GPOS-FEATURE)
638 See the documentation of `font-drive-otf' for the detail.
640 This method applies the specified features to the codes in the
641 elements of GSTRING-IN (between FROMth and TOth). The output
642 codes are stored in GSTRING-OUT at the IDXth element and the
643 following elements.
645 Return the number of output codes. If none of the features are
646 applicable to the input data, return 0. If GSTRING-OUT is too
647 short, return -1. */
648 int (*otf_drive) (struct font *font, Lisp_Object features,
649 Lisp_Object gstring_in, int from, int to,
650 Lisp_Object gstring_out, int idx, int alternate_subst);
652 /* Optional.
653 Make the font driver ready for frame F. Usually this function
654 makes some data specific to F and stores it in F by calling
655 font_put_frame_data (). */
656 int (*start_for_frame) (FRAME_PTR f);
658 /* Optional.
659 End using the driver for frame F. Usually this function free
660 some data stored for F. */
661 int (*end_for_frame) (FRAME_PTR f);
663 /* Optional.
665 Shape text in GSTRING. See the docstring of
666 `composition-get-gstring' for the format of GSTRING. If the
667 (N+1)th element of GSTRING is nil, input of shaping is from the
668 1st to (N)th elements. In each input glyph, FROM, TO, CHAR, and
669 CODE are already set.
671 This function updates all fields of the input glyphs. If the
672 output glyphs (M) are more than the input glyphs (N), (N+1)th
673 through (M)th elements of GSTRING are updated possibly by making
674 a new glyph object and storing it in GSTRING. If (M) is greater
675 than the length of GSTRING, nil should be return. In that case,
676 this function is called again with the larger GSTRING. */
677 Lisp_Object (*shape) (Lisp_Object lgstring);
679 /* Optional.
681 If FONT is usable on frame F, return 0. Otherwise return -1.
682 This method is used only for debugging. If this method is NULL,
683 Emacs assumes that the font is usable on any frame. */
684 int (*check) (FRAME_PTR F, struct font *font);
686 /* Optional.
688 Return the number of variation glyphs of character C supported by
689 FONT. VARIATIONS is an array of 256 elements. If the variation
690 selector N (1..256) defines a glyph, that glyph code is stored in
691 the (N-1)th element of VARIATIONS. */
692 int (*get_variation_glyphs) (struct font *font,
693 int c, unsigned variations[256]);
695 void (*filter_properties) (Lisp_Object font, Lisp_Object properties);
697 /* Optional.
699 Return non-zero if FONT_OBJECT can be used as a (cached) font
700 for ENTITY on frame F. */
701 int (*cached_font_ok) (struct frame *f,
702 Lisp_Object font_object,
703 Lisp_Object entity);
707 /* Chain of font drivers. There's one global font driver list
708 (font_driver_list in font.c). In addition, each frame has it's own
709 font driver list at FRAME_PTR->font_driver_list. */
711 struct font_driver_list
713 /* 1 iff this driver is currently used. It is igonred in the global
714 font driver list.*/
715 int on;
716 /* Pointer to the font driver. */
717 struct font_driver *driver;
718 /* Pointer to the next element of the chain. */
719 struct font_driver_list *next;
723 /* Chain of arbitrary data specific to each font driver. Each frame
724 has it's own font data list at FRAME_PTR->font_data_list. */
726 struct font_data_list
728 /* Pointer to the font driver. */
729 struct font_driver *driver;
730 /* Data specific to the font driver. */
731 void *data;
732 /* Pointer to the next element of the chain. */
733 struct font_data_list *next;
736 EXFUN (Ffont_spec, MANY);
737 extern Lisp_Object copy_font_spec (Lisp_Object);
738 extern Lisp_Object merge_font_spec (Lisp_Object, Lisp_Object);
739 EXFUN (Ffont_get, 2);
740 EXFUN (Ffont_put, 3);
741 EXFUN (Flist_fonts, 4);
742 EXFUN (Ffont_xlfd_name, 2);
744 extern Lisp_Object font_make_entity (void);
745 extern Lisp_Object font_make_object (int, Lisp_Object, int);
747 extern Lisp_Object find_font_encoding (Lisp_Object);
748 extern int font_registry_charsets (Lisp_Object, struct charset **,
749 struct charset **);
750 extern int font_style_to_value (enum font_property_index prop,
751 Lisp_Object name, int noerror);
752 extern Lisp_Object font_style_symbolic (Lisp_Object font,
753 enum font_property_index prop,
754 int for_face);
756 extern int font_match_p (Lisp_Object spec, Lisp_Object font);
757 extern Lisp_Object font_list_entities (Lisp_Object frame,
758 Lisp_Object spec);
760 extern Lisp_Object font_get_name (Lisp_Object font_object);
761 extern Lisp_Object font_spec_from_name (Lisp_Object font_name);
762 extern Lisp_Object font_get_frame (Lisp_Object font_object);
763 extern int font_has_char (FRAME_PTR, Lisp_Object, int);
765 extern void font_clear_prop (Lisp_Object *attrs,
766 enum font_property_index prop);
767 extern Lisp_Object font_find_for_lface (FRAME_PTR f, Lisp_Object *lface,
768 Lisp_Object spec, int c);
769 extern Lisp_Object font_open_for_lface (FRAME_PTR f, Lisp_Object entity,
770 Lisp_Object *lface,
771 Lisp_Object spec);
772 extern Lisp_Object font_load_for_lface (FRAME_PTR f, Lisp_Object *lface,
773 Lisp_Object spec);
774 extern void font_prepare_for_face (FRAME_PTR f, struct face *face);
775 extern void font_done_for_face (FRAME_PTR f, struct face *face);
777 extern Lisp_Object font_open_by_spec (FRAME_PTR f, Lisp_Object spec);
778 extern Lisp_Object font_open_by_name (FRAME_PTR f, const char *name);
780 extern Lisp_Object font_intern_prop (const char *str, int len, int force_symbol);
781 extern void font_update_sort_order (int *order);
783 extern void font_parse_family_registry (Lisp_Object family,
784 Lisp_Object registry,
785 Lisp_Object spec);
787 extern int font_parse_xlfd (char *name, Lisp_Object font);
788 extern int font_unparse_xlfd (Lisp_Object font, int pixel_size,
789 char *name, int bytes);
790 extern int font_unparse_fcname (Lisp_Object font, int pixel_size,
791 char *name, int bytes);
792 extern void register_font_driver (struct font_driver *driver, FRAME_PTR f);
793 extern void free_font_driver_list (FRAME_PTR f);
794 extern Lisp_Object font_update_drivers (FRAME_PTR f, Lisp_Object list);
795 extern Lisp_Object font_range (EMACS_INT, EMACS_INT *,
796 struct window *, struct face *,
797 Lisp_Object);
798 extern void font_fill_lglyph_metrics (Lisp_Object, Lisp_Object);
800 extern Lisp_Object font_put_extra (Lisp_Object font, Lisp_Object prop,
801 Lisp_Object val);
803 extern int font_put_frame_data (FRAME_PTR f,
804 struct font_driver *driver,
805 void *data);
806 extern void *font_get_frame_data (FRAME_PTR f,
807 struct font_driver *driver);
809 extern void font_filter_properties (Lisp_Object font,
810 Lisp_Object alist,
811 const char *const boolean_properties[],
812 const char *const non_boolean_properties[]);
814 #ifdef HAVE_FREETYPE
815 extern struct font_driver ftfont_driver;
816 extern void syms_of_ftfont (void);
817 #endif /* HAVE_FREETYPE */
818 #ifdef HAVE_X_WINDOWS
819 extern struct font_driver xfont_driver;
820 extern void syms_of_xfont (void);
821 extern void syms_of_ftxfont (void);
822 #ifdef HAVE_XFT
823 extern struct font_driver xftfont_driver;
824 extern void syms_of_xftfont (void);
825 #elif defined HAVE_FREETYPE
826 extern struct font_driver ftxfont_driver;
827 #endif
828 #ifdef HAVE_BDFFONT
829 extern void syms_of_bdffont (void);
830 #endif /* HAVE_BDFFONT */
831 #endif /* HAVE_X_WINDOWS */
832 #ifdef WINDOWSNT
833 extern struct font_driver w32font_driver;
834 extern struct font_driver uniscribe_font_driver;
835 extern void syms_of_w32font (void);
836 #endif /* WINDOWSNT */
837 #ifdef HAVE_NS
838 extern Lisp_Object Qfontsize;
839 extern struct font_driver nsfont_driver;
840 extern void syms_of_nsfont (void);
841 #endif /* HAVE_NS */
843 #ifndef FONT_DEBUG
844 #define FONT_DEBUG
845 #endif
847 extern Lisp_Object QCfoundry;
849 extern void font_add_log (const char *, Lisp_Object, Lisp_Object);
850 extern void font_deferred_log (const char *, Lisp_Object, Lisp_Object);
852 #define FONT_ADD_LOG(ACTION, ARG, RESULT) \
853 do { \
854 if (! EQ (Vfont_log, Qt)) \
855 font_add_log ((ACTION), (ARG), (RESULT)); \
856 } while (0)
858 #define FONT_DEFERRED_LOG(ACTION, ARG, RESULT) \
859 do { \
860 if (! EQ (Vfont_log, Qt)) \
861 font_deferred_log ((ACTION), (ARG), (RESULT)); \
862 } while (0)
864 #ifdef FONT_DEBUG
865 #define font_assert(X) do {if (!(X)) abort ();} while (0)
866 #else /* not FONT_DEBUG */
867 #define font_assert(X) (void) 0
868 #endif /* not FONT_DEBUG */
870 #endif /* not EMACS_FONT_H */