1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
| | /* font.h -- Interface definition for font handling.
Copyright (C) 2006-2017 Free Software Foundation, Inc.
Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
National Institute of Advanced Industrial Science and Technology (AIST)
Registration Number H13PRO009
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 3 of the License, 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. If not, see <https://www.gnu.org/licenses/>. */
#ifndef EMACS_FONT_H
#define EMACS_FONT_H
struct composition_it;
struct face;
struct glyph_string;
INLINE_HEADER_BEGIN
/* We have three types of Lisp objects related to font.
FONT-SPEC
Pseudo vector (length FONT_SPEC_MAX) of font properties. Some
properties can be left unspecified (i.e. nil). Emacs asks
font-drivers to find a font by FONT-SPEC. A fontset entry
specifies requisite properties whereas a face specifies just
preferable properties.
FONT-ENTITY
Pseudo vector (length FONT_ENTITY_MAX) of fully instantiated
font properties that a font-driver returns upon a request of
FONT-SPEC.
Note: Only the method `list' and `match' of a font-driver can
create this object, and it should never be modified by Lisp.
FONT-OBJECT
Pseudo vector (length FONT_OBJECT_MAX) of an opened font.
Lisp object encapsulating "struct font". This corresponds to
an opened font.
Note: Only the method `open' of a font-driver can create this
object, and it should never be modified by Lisp. */
/* An enumerator for each font property. This is used as an index to
the vector of FONT-SPEC and FONT-ENTITY.
Note: The order is important and should not be changed. */
enum font_property_index
{
/* FONT-TYPE is a symbol indicating a font backend; currently `x',
`xft', and `ftx' are available on X, `uniscribe' and `gdi' on
Windows, and `ns' under Cocoa / GNUstep. */
FONT_TYPE_INDEX,
/* FONT-FOUNDRY is a foundry name (symbol). */
FONT_FOUNDRY_INDEX,
/* FONT-FAMILY is a family name (symbol). */
FONT_FAMILY_INDEX,
/* FONT-ADSTYLE is an additional style name (symbol). */
FONT_ADSTYLE_INDEX,
/* FONT-REGISTRY is a combination of a charset-registry and
charset-encoding name (symbol). */
FONT_REGISTRY_INDEX,
/* FONT-WEIGHT is a numeric value of weight (e.g. medium, bold) of
the font. The lowest 8 bits is an index determining the
symbolic name, and the higher bits is the actual numeric value
defined in `font-weight-table'. */
FONT_WEIGHT_INDEX,
/* FONT-SLANT is a numeric value of slant (e.g. r, i, o) of the
font. The lowest 8 bits is an index determining the symbolic
name, and the higher bits is the actual numeric value defined
in `font-slant-table'. */
FONT_SLANT_INDEX,
/* FONT-WIDTH is a numeric value of setwidth (e.g. normal) of the
font. The lowest 8 bits is an index determining the symbolic
name, and the higher bits is the actual numeric value defined
`font-width-table'. */
FONT_WIDTH_INDEX,
/* FONT-SIZE is a size of the font. If integer, it is a pixel
size. For a font-spec, the value can be a float specifying
the point size. The value zero means that the font is
scalable. */
FONT_SIZE_INDEX,
/* FONT-DPI is a resolution (dot per inch) for which the font is
designed. */
FONT_DPI_INDEX,
/* FONT-SPACING is a spacing (mono, proportional, charcell) of the
font (integer; one of enum font_spacing). */
FONT_SPACING_INDEX,
/* FONT-AVGWIDTH is an average width (1/10 pixel unit) of the
font. */
FONT_AVGWIDTH_INDEX,
#if false
/* The following two members are to substitute for the above 6
members (FONT_WEIGHT_INDEX to FONT_AVGWIDTH_INDEX excluding
FONT_SIZE_INDEX) if it is found that font-entities consumes too
much memory. */
/* FONT-STYLE is a 24-bit integer containing indices for
style-related properties WEIGHT, SLANT, and WIDTH. The lowest
8 bits is an index to the weight table AREF (font_style_table,
0), the next 8 bits is an index to the slant table AREF
(font_style_table, 1), the highest 8 bits is an index to the
slant table AREF (font_style_table, 2). The index 0 indicates
that the corresponding style is not specified. This way, we
can represent at most 255 different names for each style, which
is surely sufficient. */
FONT_STYLE_INDEX,
/* FONT-METRICS is a 27-bit integer containing metrics-related
properties DPI, AVGWIDTH, SPACING. The lowest 12 bits is for
DPI, the next 12 bits is for AVGWIDTH, the highest 3 bits is for
SPACING. In each bit field, the highest bit indicates that the
corresponding value is set or not. This way, we can represent
DPI by 11-bit (0 to 2047), AVGWIDTH by 11-bit (0 to 2047),
SPACING by 3-bit (0 for proportional, 1 for dual, 2 for mono, 3
for charcell), which is surely sufficient. */
FONT_METRICS_INDEX,
#endif
/* In a font-spec, the value is an alist of extra information of a
font such as name, OpenType features, and language coverage.
In addition, in a font-entity, the value may contain a pair
(font-entity . INFO) where INFO is extra information to identify
a font (font-driver dependent). */
FONT_EXTRA_INDEX, /* alist alist */
/* This value is the length of font-spec vector. */
FONT_SPEC_MAX,
/* The followings are used only for a font-entity and a font-object. */
/* List of font-objects opened from the font-entity. */
FONT_OBJLIST_INDEX = FONT_SPEC_MAX,
/* This value is the length of font-entity vector. */
FONT_ENTITY_MAX,
/* The followings are used only for a font-object. */
/* XLFD name of the font (string). */
FONT_NAME_INDEX = FONT_ENTITY_MAX,
/* Full name of the font (string). It is the name extracted from
the opened font, and may be different from the above. It may be
nil if the opened font doesn't give a name. */
FONT_FULLNAME_INDEX,
/* File name of the font or nil if a file associated with the font
is not available. */
FONT_FILE_INDEX,
/* This value is the length of font-object vector. */
FONT_OBJECT_MAX
};
/* Return the numeric weight value of FONT. */
#define FONT_WEIGHT_NUMERIC(font) \
(INTEGERP (AREF ((font), FONT_WEIGHT_INDEX)) \
? (XINT (AREF ((font), FONT_WEIGHT_INDEX)) >> 8) : -1)
/* Return the numeric slant value of FONT. */
#define FONT_SLANT_NUMERIC(font) \
(INTEGERP (AREF ((font), FONT_SLANT_INDEX)) \
? (XINT (AREF ((font), FONT_SLANT_INDEX)) >> 8) : -1)
/* Return the numeric width value of FONT. */
#define FONT_WIDTH_NUMERIC(font) \
(INTEGERP (AREF ((font), FONT_WIDTH_INDEX)) \
? (XINT (AREF ((font), FONT_WIDTH_INDEX)) >> 8) : -1)
/* Return the symbolic weight value of FONT. */
#define FONT_WEIGHT_SYMBOLIC(font) \
font_style_symbolic (font, FONT_WEIGHT_INDEX, false)
/* Return the symbolic slant value of FONT. */
#define FONT_SLANT_SYMBOLIC(font) \
font_style_symbolic (font, FONT_SLANT_INDEX, false)
/* Return the symbolic width value of FONT. */
#define FONT_WIDTH_SYMBOLIC(font) \
font_style_symbolic (font, FONT_WIDTH_INDEX, false)
/* Return the face-weight corresponding to the weight of FONT. */
#define FONT_WEIGHT_FOR_FACE(font) \
font_style_symbolic (font, FONT_WEIGHT_INDEX, true)
/* Return the face-slant corresponding to the slant of FONT. */
#define FONT_SLANT_FOR_FACE(font) \
font_style_symbolic (font, FONT_SLANT_INDEX, true)
/* Return the face-swidth corresponding to the slant of FONT. */
#define FONT_WIDTH_FOR_FACE(font) \
font_style_symbolic (font, FONT_WIDTH_INDEX, true)
/* Return the numeric weight value corresponding ot the symbol NAME. */
#define FONT_WEIGHT_NAME_NUMERIC(name) \
(font_style_to_value (FONT_WEIGHT_INDEX, (name), false) >> 8)
/* Return the numeric slant value corresponding ot the symbol NAME. */
#define FONT_SLANT_NAME_NUMERIC(name) \
(font_style_to_value (FONT_SLANT_INDEX, (name), false) >> 8)
/* Return the numeric width value corresponding ot the symbol NAME. */
#define FONT_WIDTH_NAME_NUMERIC(name) \
(font_style_to_value (FONT_WIDTH_INDEX, (name), false) >> 8)
/* Set the font property PROP of FONT to VAL. PROP is one of
style-related font property index (FONT_WEIGHT/SLANT/WIDTH_INDEX).
VAL (integer or symbol) is the numeric or symbolic style value. */
#define FONT_SET_STYLE(font, prop, val) \
ASET ((font), prop, make_number (font_style_to_value (prop, val, true)))
#ifndef MSDOS
#define FONT_WIDTH(f) ((f)->max_width)
#else
#define FONT_WIDTH(f) 1
#endif
#define FONT_HEIGHT(f) ((f)->height)
#define FONT_BASE(f) ((f)->ascent)
#define FONT_DESCENT(f) ((f)->descent)
/* Structure for a font-spec. */
struct font_spec
{
struct vectorlike_header header;
Lisp_Object props[FONT_SPEC_MAX];
};
/* Structure for a font-entity. */
struct font_entity
{
struct vectorlike_header header;
Lisp_Object props[FONT_ENTITY_MAX];
};
/* A value which may appear in the member `encoding' of struct font
indicating that a font itself doesn't tell which encoding to be
used. */
#define FONT_ENCODING_NOT_DECIDED 255
/* Structure for a font-object. */
struct font
{
struct vectorlike_header header;
/* All Lisp_Object components must come first.
That ensures they are all aligned normally. */
Lisp_Object props[FONT_OBJECT_MAX];
/* Beyond here, there should be no more Lisp_Object components. */
/* Minimum and maximum glyph widths, in pixels. Some font backends,
such as xft, lack the information to easily compute minimum and
maximum widths over all characters; in that case, these values
are approximate. */
int min_width;
int max_width;
/* By which pixel size the font is opened. */
int pixel_size;
/* Height of the font. On X window, this is the same as
(font->ascent + font->descent). */
int height;
/* Width of the space glyph of the font. If the font doesn't have a
SPACE glyph, the value is 0. */
int space_width;
/* Average width of glyphs in the font. If the font itself doesn't
have that information but has glyphs of ASCII characters, the
value is the average width of those glyphs. Otherwise, the value
is 0. */
int average_width;
/* Ascent and descent of the font (in pixels). */
int ascent, descent;
/* The following members makes sense on graphic displays only. */
#if defined (HAVE_WINDOW_SYSTEM)
/* Vertical pixel width of the underline. If is zero if that
information is not in the font. */
int underline_thickness;
/* Vertical pixel position (relative to the baseline) of the
underline. If it is positive, it is below the baseline. It is
negative if that information is not in the font. */
int underline_position;
/* True if `vertical-centering-font-regexp' matches this font name.
In this case, we render characters at vertical center positions
of lines. */
bool vertical_centering;
/* The baseline position of a font is normally `ascent' value of the
font. However, there exist many fonts which don't set `ascent' to
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 user's 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 pixels
higher than normal ASCII text we should draw a character of the
font for better appearance.
We also have to consider the fact that the concept of `baseline'
differs among scripts 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 don'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 below 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;
/* Charset to encode a character code into a glyph code of the font.
-1 means that the font doesn't require this information to encode
a character. */
int encoding_charset;
/* Charset to check if a character code is supported by the font.
-1 means that the contents of the font must be looked up to
determine it. */
int repertory_charset;
#endif /* HAVE_WINDOW_SYSTEM */
/* Font-driver for the font. */
struct font_driver const *driver;
/* There are more members in this structure, but they are private
to the font-driver. */
};
enum font_spacing
{
FONT_SPACING_PROPORTIONAL = 0,
FONT_SPACING_DUAL = 90,
FONT_SPACING_MONO = 100,
FONT_SPACING_CHARCELL = 110
};
struct font_metrics
{
short lbearing, rbearing, width, ascent, descent;
};
struct font_bitmap
{
int bits_per_pixel;
int rows;
int width;
int pitch;
unsigned char *buffer;
int left;
int top;
int advance;
};
/* Predicates to check various font-related objects. */
/* True iff X is one of font-spec, font-entity, and font-object. */
INLINE bool
FONTP (Lisp_Object x)
{
return PSEUDOVECTORP (x, PVEC_FONT);
}
/* True iff X is font-spec. */
INLINE bool
FONT_SPEC_P (Lisp_Object x)
{
return FONTP (x) && PVSIZE (x) == FONT_SPEC_MAX;
}
/* Like FONT_SPEC_P, but can be used in the garbage collector. */
INLINE bool
GC_FONT_SPEC_P (Lisp_Object x)
{
return FONTP (x) && (gc_asize (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_SPEC_MAX;
}
/* True iff X is font-entity. */
INLINE bool
FONT_ENTITY_P (Lisp_Object x)
{
return FONTP (x) && PVSIZE (x) == FONT_ENTITY_MAX;
}
/* Like FONT_ENTITY_P, but can be used in the garbage collector. */
INLINE bool
GC_FONT_ENTITY_P (Lisp_Object x)
{
return FONTP (x) && (gc_asize (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_ENTITY_MAX;
}
/* True iff X is font-object. */
INLINE bool
FONT_OBJECT_P (Lisp_Object x)
{
return FONTP (x) && PVSIZE (x) == FONT_OBJECT_MAX;
}
/* Like FONT_OBJECT_P, but can be used in the garbage collector. */
INLINE bool
GC_FONT_OBJECT_P (Lisp_Object x)
{
return FONTP (x) && (gc_asize (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_OBJECT_MAX;
}
/* Type checking functions for various font-related objects. */
INLINE void
CHECK_FONT (Lisp_Object x)
{
CHECK_TYPE (FONTP (x), Qfont, x);
}
INLINE void
CHECK_FONT_SPEC (Lisp_Object x)
{
CHECK_TYPE (FONT_SPEC_P (x), Qfont_spec, x);
}
INLINE void
CHECK_FONT_ENTITY (Lisp_Object x)
{
CHECK_TYPE (FONT_ENTITY_P (x), Qfont_entity, x);
}
INLINE void
CHECK_FONT_OBJECT (Lisp_Object x)
{
CHECK_TYPE (FONT_OBJECT_P (x), Qfont_object, x);
}
/* C pointer extraction functions for various font-related objects. */
INLINE struct font_spec *
XFONT_SPEC (Lisp_Object p)
{
eassert (FONT_SPEC_P (p));
return XUNTAG (p, Lisp_Vectorlike);
}
INLINE struct font_spec *
GC_XFONT_SPEC (Lisp_Object p)
{
eassert (GC_FONT_SPEC_P (p));
return XUNTAG (p, Lisp_Vectorlike);
}
INLINE struct font_entity *
XFONT_ENTITY (Lisp_Object p)
{
eassert (FONT_ENTITY_P (p));
return XUNTAG (p, Lisp_Vectorlike);
}
INLINE struct font_entity *
GC_XFONT_ENTITY (Lisp_Object p)
{
eassert (GC_FONT_ENTITY_P (p));
return XUNTAG (p, Lisp_Vectorlike);
}
INLINE struct font *
XFONT_OBJECT (Lisp_Object p)
{
eassert (FONT_OBJECT_P (p));
return XUNTAG (p, Lisp_Vectorlike);
}
INLINE struct font *
GC_XFONT_OBJECT (Lisp_Object p)
{
eassert (GC_FONT_OBJECT_P (p));
return XUNTAG (p, Lisp_Vectorlike);
}
#define XSETFONT(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_FONT))
INLINE struct font *
CHECK_FONT_GET_OBJECT (Lisp_Object x)
{
CHECK_FONT_OBJECT (x);
return XFONT_OBJECT (x);
}
/* Number of pt per inch (from the TeXbook). */
#define PT_PER_INCH 72.27
/* Return a pixel size (integer) corresponding to POINT size (double)
on resolution DPI. */
#define POINT_TO_PIXEL(POINT, DPI) ((POINT) * (DPI) / PT_PER_INCH + 0.5)
/* Return a point size corresponding to POINT size (integer)
on resolution DPI. Note that though point size is a double, we expect
it to be rounded to an int, so we add 0.5 here. If the desired value
is tenths of points (as in xfld specs), then the pixel size should
be multiplied BEFORE the conversion to avoid magnifying the error. */
#define PIXEL_TO_POINT(PIXEL, DPI) ((PIXEL) * PT_PER_INCH / (DPI) + 0.5)
/* Ignore the difference of font pixel sizes less than or equal to
this value. */
#define FONT_PIXEL_SIZE_QUANTUM 1
#define FONT_INVALID_CODE 0xFFFFFFFF
/* Font driver. Members specified as "optional" can be NULL. */
struct font_driver
{
/* Symbol indicating the type of the font-driver. */
Lisp_Object type;
/* True iff the font's foundry, family, and adstyle names are case
sensitive. */
bool case_sensitive;
/* Return a cache of font-entities on frame F. The cache must be a
cons whose cdr part is the actual cache area. */
Lisp_Object (*get_cache) (struct frame *f);
/* List fonts exactly matching with FONT_SPEC on FRAME. The value
is a list of font-entities. The font properties to be considered
are: :foundry, :family, :adstyle, :registry, :script, :lang, and
:otf. See the function `font-spec' for their meanings. Note
that the last three properties are stored in FONT_EXTRA_INDEX
slot of FONT_SPEC.
The returned value is a list of font-entities. Each font-entity
has :type property whose value is the same as the above `type'.
It also has these properties if they are available from the
corresponding font; :foundry, :family, :adstyle, :registry,
:weight, :slant, :width, :size, :dpi, :spacing, :avgwidth. If
the font is scalable, :size and :avgwidth must be 0.
The `open' method of the same font-backend is called with one of
the returned font-entities. If the backend needs additional
information to be used in `open' method, this method can add any
Lispy value by the property :font-entity to the entities.
This and the following `match' are the only APIs that allocate
font-entities. */
Lisp_Object (*list) (struct frame *frame, Lisp_Object font_spec);
/* Return a font-entity most closely matching with FONT_SPEC on
FRAME. Which font property to consider, and how to calculate the
closeness is determined by the font backend, thus
`face-font-selection-order' is ignored here.
The properties that the font-entity has is the same as `list'
method. */
Lisp_Object (*match) (struct frame *f, Lisp_Object spec);
/* Optional.
List available families. The value is a list of family names
(symbols). */
Lisp_Object (*list_family) (struct frame *f);
/* Optional (if FONT_EXTRA_INDEX is not Lisp_Save_Value).
Free FONT_EXTRA_INDEX field of FONT_ENTITY. */
void (*free_entity) (Lisp_Object font_entity);
/* Open a font specified by FONT_ENTITY on frame F. If the font is
scalable, open it with PIXEL_SIZE. */
Lisp_Object (*open) (struct frame *f, Lisp_Object font_entity,
int pixel_size);
/* Close FONT. NOTE: this can be called by GC. */
void (*close) (struct font *font);
/* Prepare FACE for displaying characters by FONT on frame F by
storing some data in FACE->extra. */
void (*prepare_face) (struct frame *f, struct face *face);
/* Optional.
Done FACE for displaying characters by FACE->font on frame F. */
void (*done_face) (struct frame *f, struct face *face);
/* Optional.
If FONT (FONT-ENTITY or FONT-OBJECT) has a glyph for character C
(Unicode code point), return 1. If not, return 0. If FONT is
FONT-ENTITY and it must be opened to check it, return -1. */
int (*has_char) (Lisp_Object font, int c);
/* Return a glyph code of FONT for character C (Unicode code point).
If FONT doesn't have such a glyph, return FONT_INVALID_CODE. */
unsigned (*encode_char) (struct font *font, int c);
/* Compute the total metrics of the NGLYPHS glyphs specified by
the font FONT and the sequence of glyph codes CODE, and store the
result in METRICS. */
void (*text_extents) (struct font *font,
unsigned *code, int nglyphs,
struct font_metrics *metrics);
#ifdef HAVE_WINDOW_SYSTEM
/* Optional.
Draw glyphs between FROM and TO of S->char2b at (X Y) pixel
position of frame F with S->FACE and S->GC. If WITH_BACKGROUND,
fill the background in advance. It is assured that WITH_BACKGROUND
is false when (FROM > 0 || TO < S->nchars). */
int (*draw) (struct glyph_string *s, int from, int to,
int x, int y, bool with_background);
/* Optional.
Store bitmap data for glyph-code CODE of FONT in BITMAP. It is
intended that this method is called from the other font-driver
for actual drawing. */
int (*get_bitmap) (struct font *font, unsigned code,
struct font_bitmap *bitmap,
int bits_per_pixel);
/* Optional.
Free bitmap data in BITMAP. */
void (*free_bitmap) (struct font *font, struct font_bitmap *bitmap);
#endif /* HAVE_WINDOW_SYSTEM */
/* Optional.
Get coordinates of the INDEXth anchor point of the glyph whose
code is CODE. Store the coordinates in *X and *Y. Return 0 if
the operations was successful. Otherwise return -1. */
int (*anchor_point) (struct font *font, unsigned code, int index,
int *x, int *y);
/* Optional.
Return a list describing which scripts/languages FONT
supports by which GSUB/GPOS features of OpenType tables. */
Lisp_Object (*otf_capability) (struct font *font);
/* Optional.
Apply FONT's OTF-FEATURES to the glyph string.
FEATURES specifies which OTF features to apply in this format:
(SCRIPT LANGSYS GSUB-FEATURE GPOS-FEATURE)
See the documentation of `font-drive-otf' for the details.
This method applies the specified features to the codes in the
elements of GSTRING-IN (between FROMth and TOth). The output
codes are stored in GSTRING-OUT at the IDXth element and the
following elements.
Return the number of output codes. If none of the features are
applicable to the input data, return 0. If GSTRING-OUT is too
short, return -1. */
int (*otf_drive) (struct font *font, Lisp_Object features,
Lisp_Object gstring_in, int from, int to,
Lisp_Object gstring_out, int idx, bool alternate_subst);
/* Optional.
Make the font driver ready for frame F. Usually this function
makes some data specific to F and stores it in F by calling
font_put_frame_data (). */
int (*start_for_frame) (struct frame *f);
/* Optional.
End using the driver for frame F. Usually this function free
some data stored for F. */
int (*end_for_frame) (struct frame *f);
/* Optional.
Shape text in GSTRING. See the docstring of
`composition-get-gstring' for the format of GSTRING. If the
(N+1)th element of GSTRING is nil, input of shaping is from the
1st to (N)th elements. In each input glyph, FROM, TO, CHAR, and
CODE are already set.
This function updates all fields of the input glyphs. If the
output glyphs (M) are more than the input glyphs (N), (N+1)th
through (M)th elements of GSTRING are updated possibly by making
a new glyph object and storing it in GSTRING. If (M) is greater
than the length of GSTRING, nil should be return. In that case,
this function is called again with the larger GSTRING. */
Lisp_Object (*shape) (Lisp_Object lgstring);
/* Optional.
If FONT is usable on frame F, return 0. Otherwise return -1.
This method is used only for debugging. If this method is NULL,
Emacs assumes that the font is usable on any frame. */
int (*check) (struct frame *f, struct font *font);
/* Optional.
Return the number of variation glyphs of character C supported by
FONT. VARIATIONS is an array of 256 elements. If the variation
selector N (1..256) defines a glyph, that glyph code is stored in
the (N-1)th element of VARIATIONS. */
int (*get_variation_glyphs) (struct font *font,
int c, unsigned variations[256]);
void (*filter_properties) (Lisp_Object font, Lisp_Object properties);
/* Optional.
Return non-zero if FONT_OBJECT can be used as a (cached) font
for ENTITY on frame F. */
bool (*cached_font_ok) (struct frame *f,
Lisp_Object font_object,
Lisp_Object entity);
/* Optional
Return non-nil if the driver support rendering of combining
characters for FONT according to Unicode combining class. */
Lisp_Object (*combining_capability) (struct font *font);
/* Optional
Called when frame F is double-buffered and its size changes; Xft
relies on this hook to throw away its old XftDraw (which won't
work after the size change) and get a new one. */
void (*drop_xrender_surfaces) (struct frame *f);
};
/* Chain of font drivers. There's one global font driver list
(font_driver_list in font.c). In addition, each frame has
its own font driver list at F->font_driver_list. */
struct font_driver_list
{
/* True iff this driver is currently used. It is ignored in the global
font driver list.*/
bool on;
/* Pointer to the font driver. */
struct font_driver const *driver;
/* Pointer to the next element of the chain. */
struct font_driver_list *next;
};
extern Lisp_Object copy_font_spec (Lisp_Object);
extern Lisp_Object merge_font_spec (Lisp_Object, Lisp_Object);
extern Lisp_Object font_make_entity (void);
extern Lisp_Object font_make_object (int, Lisp_Object, int);
#if defined (HAVE_XFT) || defined (HAVE_FREETYPE) || defined (HAVE_NS)
extern Lisp_Object font_build_object (int, Lisp_Object, Lisp_Object, double);
#endif
extern Lisp_Object find_font_encoding (Lisp_Object);
extern int font_registry_charsets (Lisp_Object, struct charset **,
struct charset **);
extern int font_style_to_value (enum font_property_index prop,
Lisp_Object name, bool noerror);
extern Lisp_Object font_style_symbolic (Lisp_Object font,
enum font_property_index prop,
bool for_face);
extern bool font_match_p (Lisp_Object spec, Lisp_Object font);
extern Lisp_Object font_list_entities (struct frame *, Lisp_Object);
extern Lisp_Object font_get_name (Lisp_Object font_object);
extern Lisp_Object font_spec_from_name (Lisp_Object font_name);
extern Lisp_Object font_get_frame (Lisp_Object font_object);
extern int font_has_char (struct frame *, Lisp_Object, int);
extern void font_clear_prop (Lisp_Object *attrs,
enum font_property_index prop);
extern Lisp_Object font_find_for_lface (struct frame *f, Lisp_Object *lface,
Lisp_Object spec, int c);
extern Lisp_Object font_open_for_lface (struct frame *f, Lisp_Object entity,
Lisp_Object *lface,
Lisp_Object spec);
extern Lisp_Object font_load_for_lface (struct frame *f, Lisp_Object *lface,
Lisp_Object spec);
extern void font_prepare_for_face (struct frame *f, struct face *face);
extern void font_done_for_face (struct frame *f, struct face *face);
extern void clear_font_cache (struct frame *);
extern Lisp_Object font_open_by_spec (struct frame *f, Lisp_Object spec);
extern Lisp_Object font_open_by_name (struct frame *f, Lisp_Object name);
extern Lisp_Object font_intern_prop (const char *str, ptrdiff_t len,
bool force_symbol);
extern void font_update_sort_order (int *order);
extern void font_parse_family_registry (Lisp_Object family,
Lisp_Object registry,
Lisp_Object spec);
extern int font_parse_xlfd (char *name, ptrdiff_t len, Lisp_Object font);
extern ptrdiff_t font_unparse_xlfd (Lisp_Object font, int pixel_size,
char *name, int bytes);
extern void register_font_driver (struct font_driver const *, struct frame *);
extern void free_font_driver_list (struct frame *f);
#ifdef ENABLE_CHECKING
extern bool valid_font_driver (struct font_driver const *);
#else
INLINE bool
valid_font_driver (struct font_driver const *d)
{
return true;
}
#endif
extern Lisp_Object font_update_drivers (struct frame *f, Lisp_Object list);
extern Lisp_Object font_range (ptrdiff_t, ptrdiff_t, ptrdiff_t *,
struct window *, struct face *,
Lisp_Object);
extern void font_fill_lglyph_metrics (Lisp_Object, Lisp_Object);
extern Lisp_Object font_put_extra (Lisp_Object font, Lisp_Object prop,
Lisp_Object val);
#if defined (HAVE_XFT) || defined (HAVE_FREETYPE)
extern void font_put_frame_data (struct frame *, Lisp_Object, void *);
extern void *font_get_frame_data (struct frame *f, Lisp_Object);
#endif /* HAVE_XFT || HAVE_FREETYPE */
extern void font_filter_properties (Lisp_Object font,
Lisp_Object alist,
const char *const boolean_properties[],
const char *const non_boolean_properties[]);
extern void font_drop_xrender_surfaces (struct frame *f);
#ifdef HAVE_FREETYPE
extern int ftfont_anchor_point (struct font *, unsigned int, int,
int *, int *);
extern int ftfont_get_bitmap (struct font *, unsigned int,
struct font_bitmap *, int);
extern int ftfont_has_char (Lisp_Object, int);
extern int ftfont_variation_glyphs (struct font *, int, unsigned[256]);
extern Lisp_Object ftfont_combining_capability (struct font *);
extern Lisp_Object ftfont_get_cache (struct frame *);
extern Lisp_Object ftfont_list (struct frame *, Lisp_Object);
extern Lisp_Object ftfont_list_family (struct frame *);
extern Lisp_Object ftfont_match (struct frame *, Lisp_Object);
extern Lisp_Object ftfont_open (struct frame *, Lisp_Object, int);
extern Lisp_Object ftfont_otf_capability (struct font *);
extern Lisp_Object ftfont_shape (Lisp_Object);
extern unsigned ftfont_encode_char (struct font *, int);
extern void ftfont_close (struct font *);
extern void ftfont_filter_properties (Lisp_Object, Lisp_Object);
extern void ftfont_text_extents (struct font *, unsigned *, int,
struct font_metrics *);
extern void syms_of_ftfont (void);
#endif /* HAVE_FREETYPE */
#ifdef HAVE_X_WINDOWS
extern struct font_driver const xfont_driver;
extern Lisp_Object xfont_get_cache (struct frame *);
extern void syms_of_xfont (void);
extern void syms_of_ftxfont (void);
#ifdef HAVE_XFT
extern struct font_driver const xftfont_driver;
#endif
#if defined HAVE_FREETYPE || defined HAVE_XFT
extern struct font_driver const ftxfont_driver;
extern void syms_of_xftfont (void);
#endif
#ifdef HAVE_BDFFONT
extern void syms_of_bdffont (void);
#endif /* HAVE_BDFFONT */
#endif /* HAVE_X_WINDOWS */
#ifdef HAVE_NTGUI
extern struct font_driver w32font_driver;
extern struct font_driver uniscribe_font_driver;
extern void syms_of_w32font (void);
#endif /* HAVE_NTGUI */
#ifdef HAVE_NS
extern struct font_driver const nsfont_driver;
extern void syms_of_nsfont (void);
extern void syms_of_macfont (void);
#endif /* HAVE_NS */
#ifdef USE_CAIRO
extern struct font_driver const ftcrfont_driver;
extern void syms_of_ftcrfont (void);
#endif
#ifndef FONT_DEBUG
#define FONT_DEBUG
#endif
extern void font_add_log (const char *, Lisp_Object, Lisp_Object);
extern void font_deferred_log (const char *, Lisp_Object, Lisp_Object);
#define FONT_ADD_LOG(ACTION, ARG, RESULT) \
do { \
if (! EQ (Vfont_log, Qt)) \
font_add_log ((ACTION), (ARG), (RESULT)); \
} while (false)
#define FONT_DEFERRED_LOG(ACTION, ARG, RESULT) \
do { \
if (! EQ (Vfont_log, Qt)) \
font_deferred_log ((ACTION), (ARG), (RESULT)); \
} while (false)
INLINE_HEADER_END
#endif /* not EMACS_FONT_H */
|