1/*
2 * Copyright © 1998-2004 David Turner and Werner Lemberg
3 * Copyright © 2006 Behdad Esfahbod
4 * Copyright © 2007,2008,2009 Red Hat, Inc.
5 * Copyright © 2012,2013 Google, Inc.
6 *
7 * This is part of HarfBuzz, a text shaping library.
8 *
9 * Permission is hereby granted, without written agreement and without
10 * license or royalty fees, to use, copy, modify, and distribute this
11 * software and its documentation for any purpose, provided that the
12 * above copyright notice and the following two paragraphs appear in
13 * all copies of this software.
14 *
15 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
16 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
17 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
18 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
19 * DAMAGE.
20 *
21 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
22 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
23 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
24 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
25 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
26 *
27 * Red Hat Author(s): Behdad Esfahbod
28 * Google Author(s): Behdad Esfahbod
29 */
30
31#include "hb-open-type.hh"
32#include "hb-ot-layout.hh"
33#include "hb-ot-face.hh"
34#include "hb-ot-map.hh"
35#include "hb-map.hh"
36
37#include "hb-ot-kern-table.hh"
38#include "hb-ot-gasp-table.hh" // Just so we compile it; unused otherwise.
39#include "hb-ot-layout-gdef-table.hh"
40#include "hb-ot-layout-gsub-table.hh"
41#include "hb-ot-layout-gpos-table.hh"
42#include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise.
43#include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
44#include "hb-ot-name-table.hh"
45#include "hb-ot-os2-table.hh"
46
47#include "hb-aat-layout-lcar-table.hh"
48#include "hb-aat-layout-morx-table.hh"
49
50
51/**
52 * SECTION:hb-ot-layout
53 * @title: hb-ot-layout
54 * @short_description: OpenType Layout
55 * @include: hb-ot.h
56 *
57 * Functions for querying OpenType Layout features in the font face.
58 **/
59
60
61/*
62 * kern
63 */
64
65bool
66hb_ot_layout_has_kerning (hb_face_t *face)
67{
68 return face->table.kern->has_data ();
69}
70
71bool
72hb_ot_layout_has_machine_kerning (hb_face_t *face)
73{
74 return face->table.kern->has_state_machine ();
75}
76
77bool
78hb_ot_layout_has_cross_kerning (hb_face_t *face)
79{
80 return face->table.kern->has_cross_stream ();
81}
82
83void
84hb_ot_layout_kern (const hb_ot_shape_plan_t *plan,
85 hb_font_t *font,
86 hb_buffer_t *buffer)
87{
88 hb_blob_t *blob = font->face->table.kern.get_blob ();
89 const AAT::kern& kern = *blob->as<AAT::kern> ();
90
91 AAT::hb_aat_apply_context_t c (plan, font, buffer, blob);
92
93 kern.apply (&c);
94}
95
96
97/*
98 * GDEF
99 */
100
101bool
102OT::GDEF::is_blacklisted (hb_blob_t *blob,
103 hb_face_t *face) const
104{
105 /* The ugly business of blacklisting individual fonts' tables happen here!
106 * See this thread for why we finally had to bend in and do this:
107 * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
108 *
109 * In certain versions of Times New Roman Italic and Bold Italic,
110 * ASCII double quotation mark U+0022 has wrong glyph class 3 (mark)
111 * in GDEF. Many versions of Tahoma have bad GDEF tables that
112 * incorrectly classify some spacing marks such as certain IPA
113 * symbols as glyph class 3. So do older versions of Microsoft
114 * Himalaya, and the version of Cantarell shipped by Ubuntu 16.04.
115 *
116 * Nuke the GDEF tables of to avoid unwanted width-zeroing.
117 *
118 * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925
119 * https://bugzilla.mozilla.org/show_bug.cgi?id=1279693
120 * https://bugzilla.mozilla.org/show_bug.cgi?id=1279875
121 */
122#define ENCODE(x,y,z) (((uint64_t) (x) << 48) | ((uint64_t) (y) << 24) | (uint64_t) (z))
123 switch ENCODE(blob->length,
124 face->table.GSUB->table.get_length (),
125 face->table.GPOS->table.get_length ())
126 {
127 /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */
128 case ENCODE (442, 2874, 42038):
129 /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */
130 case ENCODE (430, 2874, 40662):
131 /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */
132 case ENCODE (442, 2874, 39116):
133 /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */
134 case ENCODE (430, 2874, 39374):
135 /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */
136 case ENCODE (490, 3046, 41638):
137 /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */
138 case ENCODE (478, 3046, 41902):
139 /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c tahoma.ttf from Windows 8 */
140 case ENCODE (898, 12554, 46470):
141 /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc tahomabd.ttf from Windows 8 */
142 case ENCODE (910, 12566, 47732):
143 /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e tahoma.ttf from Windows 8.1 */
144 case ENCODE (928, 23298, 59332):
145 /* sha1sum:6d400781948517c3c0441ba42acb309584b73033 tahomabd.ttf from Windows 8.1 */
146 case ENCODE (940, 23310, 60732):
147 /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
148 case ENCODE (964, 23836, 60072):
149 /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
150 case ENCODE (976, 23832, 61456):
151 /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846 tahoma.ttf from Windows 10 */
152 case ENCODE (994, 24474, 60336):
153 /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343 tahomabd.ttf from Windows 10 */
154 case ENCODE (1006, 24470, 61740):
155 /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
156 case ENCODE (1006, 24576, 61346):
157 /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
158 case ENCODE (1018, 24572, 62828):
159 /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5 tahoma.ttf from Windows 10 AU */
160 case ENCODE (1006, 24576, 61352):
161 /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2 tahomabd.ttf from Windows 10 AU */
162 case ENCODE (1018, 24572, 62834):
163 /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7 Tahoma.ttf from Mac OS X 10.9 */
164 case ENCODE (832, 7324, 47162):
165 /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba Tahoma Bold.ttf from Mac OS X 10.9 */
166 case ENCODE (844, 7302, 45474):
167 /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc himalaya.ttf from Windows 7 */
168 case ENCODE (180, 13054, 7254):
169 /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0 himalaya.ttf from Windows 8 */
170 case ENCODE (192, 12638, 7254):
171 /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427 himalaya.ttf from Windows 8.1 */
172 case ENCODE (192, 12690, 7254):
173 /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44 cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */
174 /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371 cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */
175 case ENCODE (188, 248, 3852):
176 /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */
177 /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */
178 case ENCODE (188, 264, 3426):
179 /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */
180 case ENCODE (1058, 47032, 11818):
181 /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/
182 case ENCODE (1046, 47030, 12600):
183 /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */
184 case ENCODE (1058, 71796, 16770):
185 /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */
186 case ENCODE (1046, 71790, 17862):
187 /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */
188 case ENCODE (1046, 71788, 17112):
189 /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */
190 case ENCODE (1058, 71794, 17514):
191 /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */
192 case ENCODE (1330, 109904, 57938):
193 /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */
194 case ENCODE (1330, 109904, 58972):
195 /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85 Padauk.ttf
196 * "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */
197 case ENCODE (1004, 59092, 14836):
198 return true;
199#undef ENCODE
200 }
201 return false;
202}
203
204static void
205_hb_ot_layout_set_glyph_props (hb_font_t *font,
206 hb_buffer_t *buffer)
207{
208 _hb_buffer_assert_gsubgpos_vars (buffer);
209
210 const OT::GDEF &gdef = *font->face->table.GDEF->table;
211 unsigned int count = buffer->len;
212 for (unsigned int i = 0; i < count; i++)
213 {
214 _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
215 _hb_glyph_info_clear_lig_props (&buffer->info[i]);
216 buffer->info[i].syllable() = 0;
217 }
218}
219
220/* Public API */
221
222hb_bool_t
223hb_ot_layout_has_glyph_classes (hb_face_t *face)
224{
225 return face->table.GDEF->table->has_glyph_classes ();
226}
227
228/**
229 * hb_ot_layout_get_glyph_class:
230 *
231 * Since: 0.9.7
232 **/
233hb_ot_layout_glyph_class_t
234hb_ot_layout_get_glyph_class (hb_face_t *face,
235 hb_codepoint_t glyph)
236{
237 return (hb_ot_layout_glyph_class_t) face->table.GDEF->table->get_glyph_class (glyph);
238}
239
240/**
241 * hb_ot_layout_get_glyphs_in_class:
242 *
243 * Since: 0.9.7
244 **/
245void
246hb_ot_layout_get_glyphs_in_class (hb_face_t *face,
247 hb_ot_layout_glyph_class_t klass,
248 hb_set_t *glyphs /* OUT */)
249{
250 return face->table.GDEF->table->get_glyphs_in_class (klass, glyphs);
251}
252
253unsigned int
254hb_ot_layout_get_attach_points (hb_face_t *face,
255 hb_codepoint_t glyph,
256 unsigned int start_offset,
257 unsigned int *point_count /* IN/OUT */,
258 unsigned int *point_array /* OUT */)
259{
260 return face->table.GDEF->table->get_attach_points (glyph,
261 start_offset,
262 point_count,
263 point_array);
264}
265
266unsigned int
267hb_ot_layout_get_ligature_carets (hb_font_t *font,
268 hb_direction_t direction,
269 hb_codepoint_t glyph,
270 unsigned int start_offset,
271 unsigned int *caret_count /* IN/OUT */,
272 hb_position_t *caret_array /* OUT */)
273{
274 unsigned int result_caret_count = 0;
275 unsigned int result = font->face->table.GDEF->table->get_lig_carets (font, direction, glyph, start_offset, &result_caret_count, caret_array);
276 if (result)
277 {
278 if (caret_count) *caret_count = result_caret_count;
279 }
280 else
281 result = font->face->table.lcar->get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
282 return result;
283}
284
285
286/*
287 * GSUB/GPOS
288 */
289
290bool
291OT::GSUB::is_blacklisted (hb_blob_t *blob HB_UNUSED,
292 hb_face_t *face) const
293{
294 /* Mac OS X prefers morx over GSUB. It also ships with various Indic fonts,
295 * all by 'MUTF' foundry (Tamil MN, Tamil Sangam MN, etc.), that have broken
296 * GSUB/GPOS tables. Some have GSUB with zero scripts, those are ignored by
297 * our morx/GSUB preference code. But if GSUB has non-zero scripts, we tend
298 * to prefer it over morx because we want to be consistent with other OpenType
299 * shapers.
300 *
301 * To work around broken Indic Mac system fonts, we ignore GSUB table if
302 * OS/2 VendorId is 'MUTF' and font has morx table as well.
303 *
304 * https://github.com/harfbuzz/harfbuzz/issues/1410
305 * https://github.com/harfbuzz/harfbuzz/issues/1348
306 * https://github.com/harfbuzz/harfbuzz/issues/1391
307 */
308 if (unlikely (face->table.OS2->achVendID == HB_TAG ('M','U','T','F') &&
309 face->table.morx->has_data ()))
310 return true;
311
312 return false;
313}
314
315bool
316OT::GPOS::is_blacklisted (hb_blob_t *blob HB_UNUSED,
317 hb_face_t *face HB_UNUSED) const
318{
319 return false;
320}
321
322static const OT::GSUBGPOS&
323get_gsubgpos_table (hb_face_t *face,
324 hb_tag_t table_tag)
325{
326 switch (table_tag) {
327 case HB_OT_TAG_GSUB: return *face->table.GSUB->table;
328 case HB_OT_TAG_GPOS: return *face->table.GPOS->table;
329 default: return Null(OT::GSUBGPOS);
330 }
331}
332
333
334unsigned int
335hb_ot_layout_table_get_script_tags (hb_face_t *face,
336 hb_tag_t table_tag,
337 unsigned int start_offset,
338 unsigned int *script_count /* IN/OUT */,
339 hb_tag_t *script_tags /* OUT */)
340{
341 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
342
343 return g.get_script_tags (start_offset, script_count, script_tags);
344}
345
346#define HB_OT_TAG_LATIN_SCRIPT HB_TAG ('l', 'a', 't', 'n')
347
348hb_bool_t
349hb_ot_layout_table_find_script (hb_face_t *face,
350 hb_tag_t table_tag,
351 hb_tag_t script_tag,
352 unsigned int *script_index)
353{
354 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
355 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
356
357 if (g.find_script_index (script_tag, script_index))
358 return true;
359
360 /* try finding 'DFLT' */
361 if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
362 return false;
363
364 /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
365 * including many versions of DejaVu Sans Mono! */
366 if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
367 return false;
368
369 /* try with 'latn'; some old fonts put their features there even though
370 they're really trying to support Thai, for example :( */
371 if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index))
372 return false;
373
374 if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
375 return false;
376}
377
378hb_bool_t
379hb_ot_layout_table_choose_script (hb_face_t *face,
380 hb_tag_t table_tag,
381 const hb_tag_t *script_tags,
382 unsigned int *script_index,
383 hb_tag_t *chosen_script)
384{
385 const hb_tag_t *t;
386 for (t = script_tags; *t; t++);
387 return hb_ot_layout_table_select_script (face, table_tag, t - script_tags, script_tags, script_index, chosen_script);
388}
389
390/**
391 * hb_ot_layout_table_select_script:
392 *
393 * Since: 2.0.0
394 **/
395hb_bool_t
396hb_ot_layout_table_select_script (hb_face_t *face,
397 hb_tag_t table_tag,
398 unsigned int script_count,
399 const hb_tag_t *script_tags,
400 unsigned int *script_index /* OUT */,
401 hb_tag_t *chosen_script /* OUT */)
402{
403 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
404 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
405 unsigned int i;
406
407 for (i = 0; i < script_count; i++)
408 {
409 if (g.find_script_index (script_tags[i], script_index))
410 {
411 if (chosen_script)
412 *chosen_script = script_tags[i];
413 return true;
414 }
415 }
416
417 /* try finding 'DFLT' */
418 if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
419 if (chosen_script)
420 *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
421 return false;
422 }
423
424 /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
425 if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
426 if (chosen_script)
427 *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
428 return false;
429 }
430
431 /* try with 'latn'; some old fonts put their features there even though
432 they're really trying to support Thai, for example :( */
433 if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
434 if (chosen_script)
435 *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
436 return false;
437 }
438
439 if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
440 if (chosen_script)
441 *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
442 return false;
443}
444
445unsigned int
446hb_ot_layout_table_get_feature_tags (hb_face_t *face,
447 hb_tag_t table_tag,
448 unsigned int start_offset,
449 unsigned int *feature_count /* IN/OUT */,
450 hb_tag_t *feature_tags /* OUT */)
451{
452 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
453
454 return g.get_feature_tags (start_offset, feature_count, feature_tags);
455}
456
457bool
458hb_ot_layout_table_find_feature (hb_face_t *face,
459 hb_tag_t table_tag,
460 hb_tag_t feature_tag,
461 unsigned int *feature_index)
462{
463 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
464 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
465
466 unsigned int num_features = g.get_feature_count ();
467 for (unsigned int i = 0; i < num_features; i++)
468 {
469 if (feature_tag == g.get_feature_tag (i)) {
470 if (feature_index) *feature_index = i;
471 return true;
472 }
473 }
474
475 if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
476 return false;
477}
478
479
480unsigned int
481hb_ot_layout_script_get_language_tags (hb_face_t *face,
482 hb_tag_t table_tag,
483 unsigned int script_index,
484 unsigned int start_offset,
485 unsigned int *language_count /* IN/OUT */,
486 hb_tag_t *language_tags /* OUT */)
487{
488 const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
489
490 return s.get_lang_sys_tags (start_offset, language_count, language_tags);
491}
492
493hb_bool_t
494hb_ot_layout_script_find_language (hb_face_t *face,
495 hb_tag_t table_tag,
496 unsigned int script_index,
497 hb_tag_t language_tag,
498 unsigned int *language_index)
499{
500 return hb_ot_layout_script_select_language (face,
501 table_tag,
502 script_index,
503 1,
504 &language_tag,
505 language_index);
506}
507
508/**
509 * hb_ot_layout_script_select_language:
510 *
511 * Since: 2.0.0
512 **/
513hb_bool_t
514hb_ot_layout_script_select_language (hb_face_t *face,
515 hb_tag_t table_tag,
516 unsigned int script_index,
517 unsigned int language_count,
518 const hb_tag_t *language_tags,
519 unsigned int *language_index /* OUT */)
520{
521 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX), "");
522 const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
523 unsigned int i;
524
525 for (i = 0; i < language_count; i++)
526 {
527 if (s.find_lang_sys_index (language_tags[i], language_index))
528 return true;
529 }
530
531 /* try finding 'dflt' */
532 if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
533 return false;
534
535 if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
536 return false;
537}
538
539hb_bool_t
540hb_ot_layout_language_get_required_feature_index (hb_face_t *face,
541 hb_tag_t table_tag,
542 unsigned int script_index,
543 unsigned int language_index,
544 unsigned int *feature_index)
545{
546 return hb_ot_layout_language_get_required_feature (face,
547 table_tag,
548 script_index,
549 language_index,
550 feature_index,
551 nullptr);
552}
553
554/**
555 * hb_ot_layout_language_get_required_feature:
556 *
557 * Since: 0.9.30
558 **/
559hb_bool_t
560hb_ot_layout_language_get_required_feature (hb_face_t *face,
561 hb_tag_t table_tag,
562 unsigned int script_index,
563 unsigned int language_index,
564 unsigned int *feature_index,
565 hb_tag_t *feature_tag)
566{
567 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
568 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
569
570 unsigned int index = l.get_required_feature_index ();
571 if (feature_index) *feature_index = index;
572 if (feature_tag) *feature_tag = g.get_feature_tag (index);
573
574 return l.has_required_feature ();
575}
576
577unsigned int
578hb_ot_layout_language_get_feature_indexes (hb_face_t *face,
579 hb_tag_t table_tag,
580 unsigned int script_index,
581 unsigned int language_index,
582 unsigned int start_offset,
583 unsigned int *feature_count /* IN/OUT */,
584 unsigned int *feature_indexes /* OUT */)
585{
586 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
587 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
588
589 return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
590}
591
592unsigned int
593hb_ot_layout_language_get_feature_tags (hb_face_t *face,
594 hb_tag_t table_tag,
595 unsigned int script_index,
596 unsigned int language_index,
597 unsigned int start_offset,
598 unsigned int *feature_count /* IN/OUT */,
599 hb_tag_t *feature_tags /* OUT */)
600{
601 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
602 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
603
604 static_assert ((sizeof (unsigned int) == sizeof (hb_tag_t)), "");
605 unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
606
607 if (feature_tags) {
608 unsigned int count = *feature_count;
609 for (unsigned int i = 0; i < count; i++)
610 feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
611 }
612
613 return ret;
614}
615
616
617hb_bool_t
618hb_ot_layout_language_find_feature (hb_face_t *face,
619 hb_tag_t table_tag,
620 unsigned int script_index,
621 unsigned int language_index,
622 hb_tag_t feature_tag,
623 unsigned int *feature_index)
624{
625 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
626 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
627 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
628
629 unsigned int num_features = l.get_feature_count ();
630 for (unsigned int i = 0; i < num_features; i++) {
631 unsigned int f_index = l.get_feature_index (i);
632
633 if (feature_tag == g.get_feature_tag (f_index)) {
634 if (feature_index) *feature_index = f_index;
635 return true;
636 }
637 }
638
639 if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
640 return false;
641}
642
643/**
644 * hb_ot_layout_feature_get_lookups:
645 *
646 * Since: 0.9.7
647 **/
648unsigned int
649hb_ot_layout_feature_get_lookups (hb_face_t *face,
650 hb_tag_t table_tag,
651 unsigned int feature_index,
652 unsigned int start_offset,
653 unsigned int *lookup_count /* IN/OUT */,
654 unsigned int *lookup_indexes /* OUT */)
655{
656 return hb_ot_layout_feature_with_variations_get_lookups (face,
657 table_tag,
658 feature_index,
659 HB_OT_LAYOUT_NO_VARIATIONS_INDEX,
660 start_offset,
661 lookup_count,
662 lookup_indexes);
663}
664
665/**
666 * hb_ot_layout_table_get_lookup_count:
667 *
668 * Since: 0.9.22
669 **/
670unsigned int
671hb_ot_layout_table_get_lookup_count (hb_face_t *face,
672 hb_tag_t table_tag)
673{
674 return get_gsubgpos_table (face, table_tag).get_lookup_count ();
675}
676
677
678struct hb_collect_features_context_t
679{
680 hb_collect_features_context_t (hb_face_t *face,
681 hb_tag_t table_tag,
682 hb_set_t *feature_indexes_)
683 : g (get_gsubgpos_table (face, table_tag)),
684 feature_indexes (feature_indexes_),
685 script_count(0),langsys_count(0) {}
686
687 bool visited (const OT::Script &s)
688 {
689 /* We might have Null() object here. Don't want to involve
690 * that in the memoize. So, detect empty objects and return. */
691 if (unlikely (!s.has_default_lang_sys () &&
692 !s.get_lang_sys_count ()))
693 return true;
694
695 if (script_count++ > HB_MAX_SCRIPTS)
696 return true;
697
698 return visited (s, visited_script);
699 }
700 bool visited (const OT::LangSys &l)
701 {
702 /* We might have Null() object here. Don't want to involve
703 * that in the memoize. So, detect empty objects and return. */
704 if (unlikely (!l.has_required_feature () &&
705 !l.get_feature_count ()))
706 return true;
707
708 if (langsys_count++ > HB_MAX_LANGSYS)
709 return true;
710
711 return visited (l, visited_langsys);
712 }
713
714 private:
715 template <typename T>
716 bool visited (const T &p, hb_set_t &visited_set)
717 {
718 hb_codepoint_t delta = (hb_codepoint_t) ((uintptr_t) &p - (uintptr_t) &g);
719 if (visited_set.has (delta))
720 return true;
721
722 visited_set.add (delta);
723 return false;
724 }
725
726 public:
727 const OT::GSUBGPOS &g;
728 hb_set_t *feature_indexes;
729
730 private:
731 hb_set_t visited_script;
732 hb_set_t visited_langsys;
733 unsigned int script_count;
734 unsigned int langsys_count;
735};
736
737static void
738langsys_collect_features (hb_collect_features_context_t *c,
739 const OT::LangSys &l,
740 const hb_tag_t *features)
741{
742 if (c->visited (l)) return;
743
744 if (!features)
745 {
746 /* All features. */
747 if (l.has_required_feature ())
748 c->feature_indexes->add (l.get_required_feature_index ());
749
750 l.add_feature_indexes_to (c->feature_indexes);
751 }
752 else
753 {
754 /* Ugh. Any faster way? */
755 for (; *features; features++)
756 {
757 hb_tag_t feature_tag = *features;
758 unsigned int num_features = l.get_feature_count ();
759 for (unsigned int i = 0; i < num_features; i++)
760 {
761 unsigned int feature_index = l.get_feature_index (i);
762
763 if (feature_tag == c->g.get_feature_tag (feature_index))
764 {
765 c->feature_indexes->add (feature_index);
766 break;
767 }
768 }
769 }
770 }
771}
772
773static void
774script_collect_features (hb_collect_features_context_t *c,
775 const OT::Script &s,
776 const hb_tag_t *languages,
777 const hb_tag_t *features)
778{
779 if (c->visited (s)) return;
780
781 if (!languages)
782 {
783 /* All languages. */
784 if (s.has_default_lang_sys ())
785 langsys_collect_features (c,
786 s.get_default_lang_sys (),
787 features);
788
789 unsigned int count = s.get_lang_sys_count ();
790 for (unsigned int language_index = 0; language_index < count; language_index++)
791 langsys_collect_features (c,
792 s.get_lang_sys (language_index),
793 features);
794 }
795 else
796 {
797 for (; *languages; languages++)
798 {
799 unsigned int language_index;
800 if (s.find_lang_sys_index (*languages, &language_index))
801 langsys_collect_features (c,
802 s.get_lang_sys (language_index),
803 features);
804 }
805 }
806}
807
808/**
809 * hb_ot_layout_collect_features:
810 *
811 * Since: 1.8.5
812 **/
813void
814hb_ot_layout_collect_features (hb_face_t *face,
815 hb_tag_t table_tag,
816 const hb_tag_t *scripts,
817 const hb_tag_t *languages,
818 const hb_tag_t *features,
819 hb_set_t *feature_indexes /* OUT */)
820{
821 hb_collect_features_context_t c (face, table_tag, feature_indexes);
822 if (!scripts)
823 {
824 /* All scripts. */
825 unsigned int count = c.g.get_script_count ();
826 for (unsigned int script_index = 0; script_index < count; script_index++)
827 script_collect_features (&c,
828 c.g.get_script (script_index),
829 languages,
830 features);
831 }
832 else
833 {
834 for (; *scripts; scripts++)
835 {
836 unsigned int script_index;
837 if (c.g.find_script_index (*scripts, &script_index))
838 script_collect_features (&c,
839 c.g.get_script (script_index),
840 languages,
841 features);
842 }
843 }
844}
845
846/**
847 * hb_ot_layout_collect_lookups:
848 *
849 * Since: 0.9.8
850 **/
851void
852hb_ot_layout_collect_lookups (hb_face_t *face,
853 hb_tag_t table_tag,
854 const hb_tag_t *scripts,
855 const hb_tag_t *languages,
856 const hb_tag_t *features,
857 hb_set_t *lookup_indexes /* OUT */)
858{
859 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
860
861 hb_set_t feature_indexes;
862 hb_ot_layout_collect_features (face, table_tag, scripts, languages, features, &feature_indexes);
863
864 for (hb_codepoint_t feature_index = HB_SET_VALUE_INVALID;
865 hb_set_next (&feature_indexes, &feature_index);)
866 g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes);
867}
868
869/**
870 * hb_ot_layout_lookup_collect_glyphs:
871 *
872 * Since: 0.9.7
873 **/
874void
875hb_ot_layout_lookup_collect_glyphs (hb_face_t *face,
876 hb_tag_t table_tag,
877 unsigned int lookup_index,
878 hb_set_t *glyphs_before, /* OUT. May be NULL */
879 hb_set_t *glyphs_input, /* OUT. May be NULL */
880 hb_set_t *glyphs_after, /* OUT. May be NULL */
881 hb_set_t *glyphs_output /* OUT. May be NULL */)
882{
883 OT::hb_collect_glyphs_context_t c (face,
884 glyphs_before,
885 glyphs_input,
886 glyphs_after,
887 glyphs_output);
888
889 switch (table_tag)
890 {
891 case HB_OT_TAG_GSUB:
892 {
893 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
894 l.collect_glyphs (&c);
895 return;
896 }
897 case HB_OT_TAG_GPOS:
898 {
899 const OT::PosLookup& l = face->table.GPOS->table->get_lookup (lookup_index);
900 l.collect_glyphs (&c);
901 return;
902 }
903 }
904}
905
906
907/* Variations support */
908
909hb_bool_t
910hb_ot_layout_table_find_feature_variations (hb_face_t *face,
911 hb_tag_t table_tag,
912 const int *coords,
913 unsigned int num_coords,
914 unsigned int *variations_index /* out */)
915{
916 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
917
918 return g.find_variations_index (coords, num_coords, variations_index);
919}
920
921unsigned int
922hb_ot_layout_feature_with_variations_get_lookups (hb_face_t *face,
923 hb_tag_t table_tag,
924 unsigned int feature_index,
925 unsigned int variations_index,
926 unsigned int start_offset,
927 unsigned int *lookup_count /* IN/OUT */,
928 unsigned int *lookup_indexes /* OUT */)
929{
930 static_assert ((OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX), "");
931 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
932
933 const OT::Feature &f = g.get_feature_variation (feature_index, variations_index);
934
935 return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
936}
937
938
939/*
940 * OT::GSUB
941 */
942
943hb_bool_t
944hb_ot_layout_has_substitution (hb_face_t *face)
945{
946 return face->table.GSUB->table->has_data ();
947}
948
949/**
950 * hb_ot_layout_lookup_would_substitute:
951 *
952 * Since: 0.9.7
953 **/
954hb_bool_t
955hb_ot_layout_lookup_would_substitute (hb_face_t *face,
956 unsigned int lookup_index,
957 const hb_codepoint_t *glyphs,
958 unsigned int glyphs_length,
959 hb_bool_t zero_context)
960{
961 return hb_ot_layout_lookup_would_substitute_fast (face,
962 lookup_index,
963 glyphs, glyphs_length,
964 zero_context);
965}
966
967bool
968hb_ot_layout_lookup_would_substitute_fast (hb_face_t *face,
969 unsigned int lookup_index,
970 const hb_codepoint_t *glyphs,
971 unsigned int glyphs_length,
972 bool zero_context)
973{
974 if (unlikely (lookup_index >= face->table.GSUB->lookup_count)) return false;
975 OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
976
977 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
978
979 return l.would_apply (&c, &face->table.GSUB->accels[lookup_index]);
980}
981
982void
983hb_ot_layout_substitute_start (hb_font_t *font,
984 hb_buffer_t *buffer)
985{
986_hb_ot_layout_set_glyph_props (font, buffer);
987}
988
989void
990hb_ot_layout_delete_glyphs_inplace (hb_buffer_t *buffer,
991 bool (*filter) (const hb_glyph_info_t *info))
992{
993 /* Merge clusters and delete filtered glyphs.
994 * NOTE! We can't use out-buffer as we have positioning data. */
995 unsigned int j = 0;
996 unsigned int count = buffer->len;
997 hb_glyph_info_t *info = buffer->info;
998 hb_glyph_position_t *pos = buffer->pos;
999 for (unsigned int i = 0; i < count; i++)
1000 {
1001 if (filter (&info[i]))
1002 {
1003 /* Merge clusters.
1004 * Same logic as buffer->delete_glyph(), but for in-place removal. */
1005
1006 unsigned int cluster = info[i].cluster;
1007 if (i + 1 < count && cluster == info[i + 1].cluster)
1008 continue; /* Cluster survives; do nothing. */
1009
1010 if (j)
1011 {
1012 /* Merge cluster backward. */
1013 if (cluster < info[j - 1].cluster)
1014 {
1015 unsigned int mask = info[i].mask;
1016 unsigned int old_cluster = info[j - 1].cluster;
1017 for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
1018 buffer->set_cluster (info[k - 1], cluster, mask);
1019 }
1020 continue;
1021 }
1022
1023 if (i + 1 < count)
1024 buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */
1025
1026 continue;
1027 }
1028
1029 if (j != i)
1030 {
1031 info[j] = info[i];
1032 pos[j] = pos[i];
1033 }
1034 j++;
1035 }
1036 buffer->len = j;
1037}
1038
1039/**
1040 * hb_ot_layout_lookup_substitute_closure:
1041 *
1042 * Since: 0.9.7
1043 **/
1044void
1045hb_ot_layout_lookup_substitute_closure (hb_face_t *face,
1046 unsigned int lookup_index,
1047 hb_set_t *glyphs)
1048{
1049 hb_map_t done_lookups;
1050 OT::hb_closure_context_t c (face, glyphs, &done_lookups);
1051
1052 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
1053
1054 l.closure (&c, lookup_index);
1055}
1056
1057/**
1058 * hb_ot_layout_lookups_substitute_closure:
1059 *
1060 * Compute the transitive closure of glyphs needed for all of the
1061 * provided lookups.
1062 *
1063 * Since: 1.8.1
1064 **/
1065void
1066hb_ot_layout_lookups_substitute_closure (hb_face_t *face,
1067 const hb_set_t *lookups,
1068 hb_set_t *glyphs)
1069{
1070 hb_map_t done_lookups;
1071 OT::hb_closure_context_t c (face, glyphs, &done_lookups);
1072 const OT::GSUB& gsub = *face->table.GSUB->table;
1073
1074 unsigned int iteration_count = 0;
1075 unsigned int glyphs_length;
1076 do
1077 {
1078 glyphs_length = glyphs->get_population ();
1079 if (lookups != nullptr)
1080 {
1081 for (hb_codepoint_t lookup_index = HB_SET_VALUE_INVALID; hb_set_next (lookups, &lookup_index);)
1082 gsub.get_lookup (lookup_index).closure (&c, lookup_index);
1083 }
1084 else
1085 {
1086 for (unsigned int i = 0; i < gsub.get_lookup_count (); i++)
1087 gsub.get_lookup (i).closure (&c, i);
1088 }
1089 } while (iteration_count++ <= HB_CLOSURE_MAX_STAGES &&
1090 glyphs_length != glyphs->get_population ());
1091}
1092
1093/*
1094 * OT::GPOS
1095 */
1096
1097hb_bool_t
1098hb_ot_layout_has_positioning (hb_face_t *face)
1099{
1100 return face->table.GPOS->table->has_data ();
1101}
1102
1103void
1104hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
1105{
1106 OT::GPOS::position_start (font, buffer);
1107}
1108
1109void
1110hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
1111{
1112 OT::GPOS::position_finish_advances (font, buffer);
1113}
1114
1115void
1116hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
1117{
1118 OT::GPOS::position_finish_offsets (font, buffer);
1119}
1120
1121/**
1122 * hb_ot_layout_get_size_params:
1123 *
1124 * Since: 0.9.10
1125 **/
1126hb_bool_t
1127hb_ot_layout_get_size_params (hb_face_t *face,
1128 unsigned int *design_size, /* OUT. May be NULL */
1129 unsigned int *subfamily_id, /* OUT. May be NULL */
1130 hb_ot_name_id_t *subfamily_name_id, /* OUT. May be NULL */
1131 unsigned int *range_start, /* OUT. May be NULL */
1132 unsigned int *range_end /* OUT. May be NULL */)
1133{
1134 const OT::GPOS &gpos = *face->table.GPOS->table;
1135 const hb_tag_t tag = HB_TAG ('s','i','z','e');
1136
1137 unsigned int num_features = gpos.get_feature_count ();
1138 for (unsigned int i = 0; i < num_features; i++)
1139 {
1140 if (tag == gpos.get_feature_tag (i))
1141 {
1142 const OT::Feature &f = gpos.get_feature (i);
1143 const OT::FeatureParamsSize &params = f.get_feature_params ().get_size_params (tag);
1144
1145 if (params.designSize)
1146 {
1147 if (design_size) *design_size = params.designSize;
1148 if (subfamily_id) *subfamily_id = params.subfamilyID;
1149 if (subfamily_name_id) *subfamily_name_id = params.subfamilyNameID;
1150 if (range_start) *range_start = params.rangeStart;
1151 if (range_end) *range_end = params.rangeEnd;
1152
1153 return true;
1154 }
1155 }
1156 }
1157
1158 if (design_size) *design_size = 0;
1159 if (subfamily_id) *subfamily_id = 0;
1160 if (subfamily_name_id) *subfamily_name_id = HB_OT_NAME_ID_INVALID;
1161 if (range_start) *range_start = 0;
1162 if (range_end) *range_end = 0;
1163
1164 return false;
1165}
1166
1167/**
1168 * hb_ot_layout_feature_get_name_ids:
1169 * @face: #hb_face_t to work upon
1170 * @table_tag: table tag to query, "GSUB" or "GPOS".
1171 * @feature_index: index of feature to query.
1172 * @label_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
1173 * for a user-interface label for this feature. (May be NULL.)
1174 * @tooltip_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
1175 * that an application can use for tooltip text for this
1176 * feature. (May be NULL.)
1177 * @sample_id: (out) (allow-none): The ‘name’ table name ID that specifies sample text
1178 * that illustrates the effect of this feature. (May be NULL.)
1179 * @num_named_parameters: (out) (allow-none): Number of named parameters. (May be zero.)
1180 * @first_param_id: (out) (allow-none): The first ‘name’ table name ID used to specify
1181 * strings for user-interface labels for the feature
1182 * parameters. (Must be zero if numParameters is zero.)
1183 *
1184 * Fetches name indices from feature parameters for "Stylistic Set" ('ssXX') or
1185 * "Character Variant" ('cvXX') features.
1186 *
1187 * Return value: true if data found, false otherwise
1188 *
1189 * Since: 2.0.0
1190 **/
1191hb_bool_t
1192hb_ot_layout_feature_get_name_ids (hb_face_t *face,
1193 hb_tag_t table_tag,
1194 unsigned int feature_index,
1195 hb_ot_name_id_t *label_id, /* OUT. May be NULL */
1196 hb_ot_name_id_t *tooltip_id, /* OUT. May be NULL */
1197 hb_ot_name_id_t *sample_id, /* OUT. May be NULL */
1198 unsigned int *num_named_parameters, /* OUT. May be NULL */
1199 hb_ot_name_id_t *first_param_id /* OUT. May be NULL */)
1200{
1201 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1202
1203 hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1204 const OT::Feature &f = g.get_feature (feature_index);
1205
1206 const OT::FeatureParams &feature_params = f.get_feature_params ();
1207 if (&feature_params != &Null (OT::FeatureParams))
1208 {
1209 const OT::FeatureParamsStylisticSet& ss_params =
1210 feature_params.get_stylistic_set_params (feature_tag);
1211 if (&ss_params != &Null (OT::FeatureParamsStylisticSet)) /* ssXX */
1212 {
1213 if (label_id) *label_id = ss_params.uiNameID;
1214 // ssXX features don't have the rest
1215 if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1216 if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1217 if (num_named_parameters) *num_named_parameters = 0;
1218 if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1219 return true;
1220 }
1221 const OT::FeatureParamsCharacterVariants& cv_params =
1222 feature_params.get_character_variants_params (feature_tag);
1223 if (&cv_params != &Null (OT::FeatureParamsCharacterVariants)) /* cvXX */
1224 {
1225 if (label_id) *label_id = cv_params.featUILableNameID;
1226 if (tooltip_id) *tooltip_id = cv_params.featUITooltipTextNameID;
1227 if (sample_id) *sample_id = cv_params.sampleTextNameID;
1228 if (num_named_parameters) *num_named_parameters = cv_params.numNamedParameters;
1229 if (first_param_id) *first_param_id = cv_params.firstParamUILabelNameID;
1230 return true;
1231 }
1232 }
1233
1234 if (label_id) *label_id = HB_OT_NAME_ID_INVALID;
1235 if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1236 if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1237 if (num_named_parameters) *num_named_parameters = 0;
1238 if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1239 return false;
1240}
1241
1242/**
1243 * hb_ot_layout_feature_get_characters:
1244 * @face: #hb_face_t to work upon
1245 * @table_tag: table tag to query, "GSUB" or "GPOS".
1246 * @feature_index: index of feature to query.
1247 * @start_offset: In case the resulting char_count was equal to its input value, there
1248 * is a chance there were more characters on the tag so this API can be
1249 * called with an offset till resulting char_count gets to a number
1250 * lower than input buffer (or consider using just a bigger buffer for
1251 * one shot copying).
1252 * @char_count: (inout) (allow-none): The count of characters for which this feature
1253 * provides glyph variants. (May be zero.)
1254 * @characters: (out caller-allocates) (array length=char_count): A buffer pointer. The Unicode codepoints
1255 * of the characters for which this feature provides glyph variants.
1256 *
1257 * Fetches characters listed by designer under feature parameters for "Character
1258 * Variant" ("cvXX") features.
1259 *
1260 * Return value: Number of total sample characters in the cvXX feature.
1261 *
1262 * Since: 2.0.0
1263 **/
1264unsigned int
1265hb_ot_layout_feature_get_characters (hb_face_t *face,
1266 hb_tag_t table_tag,
1267 unsigned int feature_index,
1268 unsigned int start_offset,
1269 unsigned int *char_count, /* IN/OUT. May be NULL */
1270 hb_codepoint_t *characters /* OUT. May be NULL */)
1271{
1272 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1273
1274 hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1275 const OT::Feature &f = g.get_feature (feature_index);
1276
1277 const OT::FeatureParams &feature_params = f.get_feature_params ();
1278
1279 const OT::FeatureParamsCharacterVariants& cv_params =
1280 feature_params.get_character_variants_params(feature_tag);
1281
1282 unsigned int len = 0;
1283 if (char_count && characters && start_offset < cv_params.characters.len)
1284 {
1285 len = MIN (cv_params.characters.len - start_offset, *char_count);
1286 for (unsigned int i = 0; i < len; ++i)
1287 characters[i] = cv_params.characters[start_offset + i];
1288 }
1289 if (char_count) *char_count = len;
1290 return cv_params.characters.len;
1291}
1292
1293
1294/*
1295 * Parts of different types are implemented here such that they have direct
1296 * access to GSUB/GPOS lookups.
1297 */
1298
1299
1300struct GSUBProxy
1301{
1302 static constexpr unsigned table_index = 0u;
1303 static constexpr bool inplace = false;
1304 typedef OT::SubstLookup Lookup;
1305
1306 GSUBProxy (hb_face_t *face) :
1307 table (*face->table.GSUB->table),
1308 accels (face->table.GSUB->accels) {}
1309
1310 const OT::GSUB &table;
1311 const OT::hb_ot_layout_lookup_accelerator_t *accels;
1312};
1313
1314struct GPOSProxy
1315{
1316 static constexpr unsigned table_index = 1u;
1317 static constexpr bool inplace = true;
1318 typedef OT::PosLookup Lookup;
1319
1320 GPOSProxy (hb_face_t *face) :
1321 table (*face->table.GPOS->table),
1322 accels (face->table.GPOS->accels) {}
1323
1324 const OT::GPOS &table;
1325 const OT::hb_ot_layout_lookup_accelerator_t *accels;
1326};
1327
1328
1329static inline bool
1330apply_forward (OT::hb_ot_apply_context_t *c,
1331 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1332{
1333 bool ret = false;
1334 hb_buffer_t *buffer = c->buffer;
1335 while (buffer->idx < buffer->len && buffer->successful)
1336 {
1337 bool applied = false;
1338 if (accel.may_have (buffer->cur().codepoint) &&
1339 (buffer->cur().mask & c->lookup_mask) &&
1340 c->check_glyph_property (&buffer->cur(), c->lookup_props))
1341 {
1342 applied = accel.apply (c);
1343 }
1344
1345 if (applied)
1346 ret = true;
1347 else
1348 buffer->next_glyph ();
1349 }
1350 return ret;
1351}
1352
1353static inline bool
1354apply_backward (OT::hb_ot_apply_context_t *c,
1355 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1356{
1357 bool ret = false;
1358 hb_buffer_t *buffer = c->buffer;
1359 do
1360 {
1361 if (accel.may_have (buffer->cur().codepoint) &&
1362 (buffer->cur().mask & c->lookup_mask) &&
1363 c->check_glyph_property (&buffer->cur(), c->lookup_props))
1364 ret |= accel.apply (c);
1365
1366 /* The reverse lookup doesn't "advance" cursor (for good reason). */
1367 buffer->idx--;
1368
1369 }
1370 while ((int) buffer->idx >= 0);
1371 return ret;
1372}
1373
1374template <typename Proxy>
1375static inline void
1376apply_string (OT::hb_ot_apply_context_t *c,
1377 const typename Proxy::Lookup &lookup,
1378 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1379{
1380 hb_buffer_t *buffer = c->buffer;
1381
1382 if (unlikely (!buffer->len || !c->lookup_mask))
1383 return;
1384
1385 c->set_lookup_props (lookup.get_props ());
1386
1387 if (likely (!lookup.is_reverse ()))
1388 {
1389 /* in/out forward substitution/positioning */
1390 if (Proxy::table_index == 0u)
1391 buffer->clear_output ();
1392 buffer->idx = 0;
1393
1394 bool ret;
1395 ret = apply_forward (c, accel);
1396 if (ret)
1397 {
1398 if (!Proxy::inplace)
1399 buffer->swap_buffers ();
1400 else
1401 assert (!buffer->has_separate_output ());
1402 }
1403 }
1404 else
1405 {
1406 /* in-place backward substitution/positioning */
1407 if (Proxy::table_index == 0u)
1408 buffer->remove_output ();
1409 buffer->idx = buffer->len - 1;
1410
1411 apply_backward (c, accel);
1412 }
1413}
1414
1415template <typename Proxy>
1416inline void hb_ot_map_t::apply (const Proxy &proxy,
1417 const hb_ot_shape_plan_t *plan,
1418 hb_font_t *font,
1419 hb_buffer_t *buffer) const
1420{
1421 const unsigned int table_index = proxy.table_index;
1422 unsigned int i = 0;
1423 OT::hb_ot_apply_context_t c (table_index, font, buffer);
1424 c.set_recurse_func (Proxy::Lookup::apply_recurse_func);
1425
1426 for (unsigned int stage_index = 0; stage_index < stages[table_index].length; stage_index++) {
1427 const stage_map_t *stage = &stages[table_index][stage_index];
1428 for (; i < stage->last_lookup; i++)
1429 {
1430 unsigned int lookup_index = lookups[table_index][i].index;
1431 if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
1432 c.set_lookup_index (lookup_index);
1433 c.set_lookup_mask (lookups[table_index][i].mask);
1434 c.set_auto_zwj (lookups[table_index][i].auto_zwj);
1435 c.set_auto_zwnj (lookups[table_index][i].auto_zwnj);
1436 if (lookups[table_index][i].random)
1437 {
1438 c.set_random (true);
1439 buffer->unsafe_to_break_all ();
1440 }
1441 apply_string<Proxy> (&c,
1442 proxy.table.get_lookup (lookup_index),
1443 proxy.accels[lookup_index]);
1444 (void) buffer->message (font, "end lookup %d", lookup_index);
1445 }
1446
1447 if (stage->pause_func)
1448 {
1449 buffer->clear_output ();
1450 stage->pause_func (plan, font, buffer);
1451 }
1452 }
1453}
1454
1455void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1456{
1457 GSUBProxy proxy (font->face);
1458 apply (proxy, plan, font, buffer);
1459}
1460
1461void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1462{
1463 GPOSProxy proxy (font->face);
1464 apply (proxy, plan, font, buffer);
1465}
1466
1467void
1468hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
1469 const OT::SubstLookup &lookup,
1470 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1471{
1472 apply_string<GSUBProxy> (c, lookup, accel);
1473}
1474
1475#if 0
1476static const OT::BASE& _get_base (hb_face_t *face)
1477{
1478 return *face->table.BASE;
1479}
1480
1481hb_bool_t
1482hb_ot_layout_get_baseline (hb_font_t *font,
1483 hb_ot_layout_baseline_t baseline,
1484 hb_direction_t direction,
1485 hb_tag_t script_tag,
1486 hb_tag_t language_tag,
1487 hb_position_t *coord /* OUT. May be NULL. */)
1488{
1489 const OT::BASE &base = _get_base (font->face);
1490 bool result = base.get_baseline (font, baseline, direction, script_tag,
1491 language_tag, coord);
1492
1493 /* TODO: Simulate https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags#ideographic-em-box */
1494 if (!result && coord) *coord = 0;
1495
1496 if (coord) *coord = font->em_scale_dir (*coord, direction);
1497
1498 return result;
1499}
1500
1501/* To be moved to public header */
1502/*
1503 * BASE
1504 */
1505
1506/**
1507 * hb_ot_layout_baseline_t:
1508 *
1509 * https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags
1510 *
1511 * Since: DONTREPLACEME
1512 */
1513typedef enum {
1514 HB_OT_LAYOUT_BASELINE_HANG = HB_TAG('h','a','n','g'),
1515 HB_OT_LAYOUT_BASELINE_ICFB = HB_TAG('i','c','f','b'),
1516 HB_OT_LAYOUT_BASELINE_ICFT = HB_TAG('i','c','f','t'),
1517 HB_OT_LAYOUT_BASELINE_IDEO = HB_TAG('i','d','e','o'),
1518 HB_OT_LAYOUT_BASELINE_IDTB = HB_TAG('i','d','t','b'),
1519 HB_OT_LAYOUT_BASELINE_MATH = HB_TAG('m','a','t','h'),
1520 HB_OT_LAYOUT_BASELINE_ROMN = HB_TAG('r','o','m','n')
1521} hb_ot_layout_baseline_t;
1522
1523HB_EXTERN hb_bool_t
1524hb_ot_layout_get_baseline (hb_font_t *font,
1525 hb_ot_layout_baseline_t baseline,
1526 hb_direction_t direction,
1527 hb_tag_t script_tag,
1528 hb_tag_t language_tag,
1529 hb_position_t *coord /* OUT. May be NULL. */);
1530
1531#endif
1532