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.hh"
32
33#ifndef HB_NO_OT_LAYOUT
34
35#ifdef HB_NO_OT_TAG
36#error "Cannot compile hb-ot-layout.cc with HB_NO_OT_TAG."
37#endif
38
39#include "hb-open-type.hh"
40#include "hb-ot-layout.hh"
41#include "hb-ot-face.hh"
42#include "hb-ot-map.hh"
43#include "hb-map.hh"
44
45#include "hb-ot-kern-table.hh"
46#include "hb-ot-layout-gdef-table.hh"
47#include "hb-ot-layout-gsub-table.hh"
48#include "hb-ot-layout-gpos-table.hh"
49#include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise.
50#include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
51#include "hb-ot-name-table.hh"
52#include "hb-ot-os2-table.hh"
53
54#include "hb-aat-layout-lcar-table.hh"
55#include "hb-aat-layout-morx-table.hh"
56
57#include "hb-aat-layout-opbd-table.hh" // Just so we compile it; unused otherwise.
58
59/**
60 * SECTION:hb-ot-layout
61 * @title: hb-ot-layout
62 * @short_description: OpenType Layout
63 * @include: hb-ot.h
64 *
65 * Functions for querying OpenType Layout features in the font face.
66 **/
67
68
69/*
70 * kern
71 */
72
73#ifndef HB_NO_OT_KERN
74/**
75 * hb_ot_layout_has_kerning:
76 * @face: The #hb_face_t to work on
77 *
78 * Tests whether a face includes any kerning data in the 'kern' table.
79 * Does NOT test for kerning lookups in the GPOS table.
80 *
81 * Return value: true if data found, false otherwise
82 *
83 **/
84bool
85hb_ot_layout_has_kerning (hb_face_t *face)
86{
87 return face->table.kern->has_data ();
88}
89
90/**
91 * hb_ot_layout_has_machine_kerning:
92 * @face: The #hb_face_t to work on
93 *
94 * Tests whether a face includes any state-machine kerning in the 'kern' table.
95 * Does NOT examine the GPOS table.
96 *
97 * Return value: true if data found, false otherwise
98 *
99 **/
100bool
101hb_ot_layout_has_machine_kerning (hb_face_t *face)
102{
103 return face->table.kern->has_state_machine ();
104}
105
106/**
107 * hb_ot_layout_has_cross_kerning:
108 * @face: The #hb_face_t to work on
109 *
110 * Tests whether a face has any cross-stream kerning (i.e., kerns
111 * that make adjustments perpendicular to the direction of the text
112 * flow: Y adjustments in horizontal text or X adjustments in
113 * vertical text) in the 'kern' table.
114 *
115 * Does NOT examine the GPOS table.
116 *
117 * Return value: true is data found, false otherwise
118 *
119 **/
120bool
121hb_ot_layout_has_cross_kerning (hb_face_t *face)
122{
123 return face->table.kern->has_cross_stream ();
124}
125
126void
127hb_ot_layout_kern (const hb_ot_shape_plan_t *plan,
128 hb_font_t *font,
129 hb_buffer_t *buffer)
130{
131 hb_blob_t *blob = font->face->table.kern.get_blob ();
132 const AAT::kern& kern = *blob->as<AAT::kern> ();
133
134 AAT::hb_aat_apply_context_t c (plan, font, buffer, blob);
135
136 kern.apply (&c);
137}
138#endif
139
140
141/*
142 * GDEF
143 */
144
145bool
146OT::GDEF::is_blacklisted (hb_blob_t *blob,
147 hb_face_t *face) const
148{
149#ifdef HB_NO_OT_LAYOUT_BLACKLIST
150 return false;
151#endif
152 /* The ugly business of blacklisting individual fonts' tables happen here!
153 * See this thread for why we finally had to bend in and do this:
154 * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
155 *
156 * In certain versions of Times New Roman Italic and Bold Italic,
157 * ASCII double quotation mark U+0022 has wrong glyph class 3 (mark)
158 * in GDEF. Many versions of Tahoma have bad GDEF tables that
159 * incorrectly classify some spacing marks such as certain IPA
160 * symbols as glyph class 3. So do older versions of Microsoft
161 * Himalaya, and the version of Cantarell shipped by Ubuntu 16.04.
162 *
163 * Nuke the GDEF tables of to avoid unwanted width-zeroing.
164 *
165 * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925
166 * https://bugzilla.mozilla.org/show_bug.cgi?id=1279693
167 * https://bugzilla.mozilla.org/show_bug.cgi?id=1279875
168 */
169 switch HB_CODEPOINT_ENCODE3(blob->length,
170 face->table.GSUB->table.get_length (),
171 face->table.GPOS->table.get_length ())
172 {
173 /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */
174 case HB_CODEPOINT_ENCODE3 (442, 2874, 42038):
175 /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */
176 case HB_CODEPOINT_ENCODE3 (430, 2874, 40662):
177 /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */
178 case HB_CODEPOINT_ENCODE3 (442, 2874, 39116):
179 /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */
180 case HB_CODEPOINT_ENCODE3 (430, 2874, 39374):
181 /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */
182 case HB_CODEPOINT_ENCODE3 (490, 3046, 41638):
183 /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */
184 case HB_CODEPOINT_ENCODE3 (478, 3046, 41902):
185 /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c tahoma.ttf from Windows 8 */
186 case HB_CODEPOINT_ENCODE3 (898, 12554, 46470):
187 /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc tahomabd.ttf from Windows 8 */
188 case HB_CODEPOINT_ENCODE3 (910, 12566, 47732):
189 /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e tahoma.ttf from Windows 8.1 */
190 case HB_CODEPOINT_ENCODE3 (928, 23298, 59332):
191 /* sha1sum:6d400781948517c3c0441ba42acb309584b73033 tahomabd.ttf from Windows 8.1 */
192 case HB_CODEPOINT_ENCODE3 (940, 23310, 60732):
193 /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
194 case HB_CODEPOINT_ENCODE3 (964, 23836, 60072):
195 /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
196 case HB_CODEPOINT_ENCODE3 (976, 23832, 61456):
197 /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846 tahoma.ttf from Windows 10 */
198 case HB_CODEPOINT_ENCODE3 (994, 24474, 60336):
199 /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343 tahomabd.ttf from Windows 10 */
200 case HB_CODEPOINT_ENCODE3 (1006, 24470, 61740):
201 /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
202 case HB_CODEPOINT_ENCODE3 (1006, 24576, 61346):
203 /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
204 case HB_CODEPOINT_ENCODE3 (1018, 24572, 62828):
205 /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5 tahoma.ttf from Windows 10 AU */
206 case HB_CODEPOINT_ENCODE3 (1006, 24576, 61352):
207 /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2 tahomabd.ttf from Windows 10 AU */
208 case HB_CODEPOINT_ENCODE3 (1018, 24572, 62834):
209 /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7 Tahoma.ttf from Mac OS X 10.9 */
210 case HB_CODEPOINT_ENCODE3 (832, 7324, 47162):
211 /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba Tahoma Bold.ttf from Mac OS X 10.9 */
212 case HB_CODEPOINT_ENCODE3 (844, 7302, 45474):
213 /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc himalaya.ttf from Windows 7 */
214 case HB_CODEPOINT_ENCODE3 (180, 13054, 7254):
215 /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0 himalaya.ttf from Windows 8 */
216 case HB_CODEPOINT_ENCODE3 (192, 12638, 7254):
217 /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427 himalaya.ttf from Windows 8.1 */
218 case HB_CODEPOINT_ENCODE3 (192, 12690, 7254):
219 /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44 cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */
220 /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371 cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */
221 case HB_CODEPOINT_ENCODE3 (188, 248, 3852):
222 /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */
223 /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */
224 case HB_CODEPOINT_ENCODE3 (188, 264, 3426):
225 /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */
226 case HB_CODEPOINT_ENCODE3 (1058, 47032, 11818):
227 /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/
228 case HB_CODEPOINT_ENCODE3 (1046, 47030, 12600):
229 /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */
230 case HB_CODEPOINT_ENCODE3 (1058, 71796, 16770):
231 /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */
232 case HB_CODEPOINT_ENCODE3 (1046, 71790, 17862):
233 /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */
234 case HB_CODEPOINT_ENCODE3 (1046, 71788, 17112):
235 /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */
236 case HB_CODEPOINT_ENCODE3 (1058, 71794, 17514):
237 /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */
238 case HB_CODEPOINT_ENCODE3 (1330, 109904, 57938):
239 /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */
240 case HB_CODEPOINT_ENCODE3 (1330, 109904, 58972):
241 /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85 Padauk.ttf
242 * "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */
243 case HB_CODEPOINT_ENCODE3 (1004, 59092, 14836):
244 return true;
245 }
246 return false;
247}
248
249static void
250_hb_ot_layout_set_glyph_props (hb_font_t *font,
251 hb_buffer_t *buffer)
252{
253 _hb_buffer_assert_gsubgpos_vars (buffer);
254
255 const OT::GDEF &gdef = *font->face->table.GDEF->table;
256 unsigned int count = buffer->len;
257 for (unsigned int i = 0; i < count; i++)
258 {
259 _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
260 _hb_glyph_info_clear_lig_props (&buffer->info[i]);
261 buffer->info[i].syllable() = 0;
262 }
263}
264
265/* Public API */
266
267/**
268 * hb_ot_layout_has_glyph_classes:
269 * @face: #hb_face_t to work upon
270 *
271 * Tests whether a face has any glyph classes defined in its GDEF table.
272 *
273 * Return value: true if data found, false otherwise
274 *
275 **/
276hb_bool_t
277hb_ot_layout_has_glyph_classes (hb_face_t *face)
278{
279 return face->table.GDEF->table->has_glyph_classes ();
280}
281
282/**
283 * hb_ot_layout_get_glyph_class:
284 * @face: The #hb_face_t to work on
285 * @glyph: The #hb_codepoint_t code point to query
286 *
287 * Fetches the GDEF class of the requested glyph in the specified face.
288 *
289 * Return value: The #hb_ot_layout_glyph_class_t glyph class of the given code
290 * point in the GDEF table of the face.
291 *
292 * Since: 0.9.7
293 **/
294hb_ot_layout_glyph_class_t
295hb_ot_layout_get_glyph_class (hb_face_t *face,
296 hb_codepoint_t glyph)
297{
298 return (hb_ot_layout_glyph_class_t) face->table.GDEF->table->get_glyph_class (glyph);
299}
300
301/**
302 * hb_ot_layout_get_glyphs_in_class:
303 * @face: The #hb_face_t to work on
304 * @klass: The #hb_ot_layout_glyph_class_t GDEF class to retrieve
305 * @glyphs: (out): The #hb_set_t set of all glyphs belonging to the requested
306 * class.
307 *
308 * Retrieves the set of all glyphs from the face that belong to the requested
309 * glyph class in the face's GDEF table.
310 *
311 * Since: 0.9.7
312 **/
313void
314hb_ot_layout_get_glyphs_in_class (hb_face_t *face,
315 hb_ot_layout_glyph_class_t klass,
316 hb_set_t *glyphs /* OUT */)
317{
318 return face->table.GDEF->table->get_glyphs_in_class (klass, glyphs);
319}
320
321
322#ifndef HB_NO_LAYOUT_UNUSED
323/**
324 * hb_ot_layout_get_attach_points:
325 * @face: The #hb_face_t to work on
326 * @glyph: The #hb_codepoint_t code point to query
327 * @start_offset: offset of the first attachment point to retrieve
328 * @point_count: (inout) (allow-none): Input = the maximum number of attachment points to return;
329 * Output = the actual number of attachment points returned (may be zero)
330 * @point_array: (out) (array length=point_count): The array of attachment points found for the query
331 *
332 * Fetches a list of all attachment points for the specified glyph in the GDEF
333 * table of the face. The list returned will begin at the offset provided.
334 *
335 * Useful if the client program wishes to cache the list.
336 *
337 **/
338unsigned int
339hb_ot_layout_get_attach_points (hb_face_t *face,
340 hb_codepoint_t glyph,
341 unsigned int start_offset,
342 unsigned int *point_count /* IN/OUT */,
343 unsigned int *point_array /* OUT */)
344{
345 return face->table.GDEF->table->get_attach_points (glyph,
346 start_offset,
347 point_count,
348 point_array);
349}
350/**
351 * hb_ot_layout_get_ligature_carets:
352 * @font: The #hb_font_t to work on
353 * @direction: The #hb_direction_t text direction to use
354 * @glyph: The #hb_codepoint_t code point to query
355 * @start_offset: offset of the first caret position to retrieve
356 * @caret_count: (inout) (allow-none): Input = the maximum number of caret positions to return;
357 * Output = the actual number of caret positions returned (may be zero)
358 * @caret_array: (out) (array length=caret_count): The array of caret positions found for the query
359 *
360 * Fetches a list of the caret positions defined for a ligature glyph in the GDEF
361 * table of the font. The list returned will begin at the offset provided.
362 *
363 **/
364unsigned int
365hb_ot_layout_get_ligature_carets (hb_font_t *font,
366 hb_direction_t direction,
367 hb_codepoint_t glyph,
368 unsigned int start_offset,
369 unsigned int *caret_count /* IN/OUT */,
370 hb_position_t *caret_array /* OUT */)
371{
372 unsigned int result_caret_count = 0;
373 unsigned int result = font->face->table.GDEF->table->get_lig_carets (font, direction, glyph, start_offset, &result_caret_count, caret_array);
374 if (result)
375 {
376 if (caret_count) *caret_count = result_caret_count;
377 }
378 else
379 {
380#ifndef HB_NO_AAT
381 result = font->face->table.lcar->get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
382#else
383 if (caret_count) *caret_count = 0;
384#endif
385 }
386 return result;
387}
388#endif
389
390
391/*
392 * GSUB/GPOS
393 */
394
395bool
396OT::GSUB::is_blacklisted (hb_blob_t *blob HB_UNUSED,
397 hb_face_t *face) const
398{
399#ifdef HB_NO_OT_LAYOUT_BLACKLIST
400 return false;
401#endif
402
403#ifndef HB_NO_AAT_SHAPE
404 /* Mac OS X prefers morx over GSUB. It also ships with various Indic fonts,
405 * all by 'MUTF' foundry (Tamil MN, Tamil Sangam MN, etc.), that have broken
406 * GSUB/GPOS tables. Some have GSUB with zero scripts, those are ignored by
407 * our morx/GSUB preference code. But if GSUB has non-zero scripts, we tend
408 * to prefer it over morx because we want to be consistent with other OpenType
409 * shapers.
410 *
411 * To work around broken Indic Mac system fonts, we ignore GSUB table if
412 * OS/2 VendorId is 'MUTF' and font has morx table as well.
413 *
414 * https://github.com/harfbuzz/harfbuzz/issues/1410
415 * https://github.com/harfbuzz/harfbuzz/issues/1348
416 * https://github.com/harfbuzz/harfbuzz/issues/1391
417 */
418 if (unlikely (face->table.OS2->achVendID == HB_TAG ('M','U','T','F') &&
419 face->table.morx->has_data ()))
420 return true;
421#endif
422
423 return false;
424}
425
426bool
427OT::GPOS::is_blacklisted (hb_blob_t *blob HB_UNUSED,
428 hb_face_t *face HB_UNUSED) const
429{
430#ifdef HB_NO_OT_LAYOUT_BLACKLIST
431 return false;
432#endif
433 return false;
434}
435
436static const OT::GSUBGPOS&
437get_gsubgpos_table (hb_face_t *face,
438 hb_tag_t table_tag)
439{
440 switch (table_tag) {
441 case HB_OT_TAG_GSUB: return *face->table.GSUB->table;
442 case HB_OT_TAG_GPOS: return *face->table.GPOS->table;
443 default: return Null(OT::GSUBGPOS);
444 }
445}
446
447
448/**
449 * hb_ot_layout_table_get_script_tags:
450 * @face: #hb_face_t to work upon
451 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
452 * @start_offset: offset of the first script tag to retrieve
453 * @script_count: (inout) (allow-none): Input = the maximum number of script tags to return;
454 * Output = the actual number of script tags returned (may be zero)
455 * @script_tags: (out) (array length=script_count): The array of #hb_tag_t script tags found for the query
456 *
457 * Fetches a list of all scripts enumerated in the specified face's GSUB table
458 * or GPOS table. The list returned will begin at the offset provided.
459 *
460 **/
461unsigned int
462hb_ot_layout_table_get_script_tags (hb_face_t *face,
463 hb_tag_t table_tag,
464 unsigned int start_offset,
465 unsigned int *script_count /* IN/OUT */,
466 hb_tag_t *script_tags /* OUT */)
467{
468 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
469
470 return g.get_script_tags (start_offset, script_count, script_tags);
471}
472
473#define HB_OT_TAG_LATIN_SCRIPT HB_TAG ('l', 'a', 't', 'n')
474
475/**
476 * hb_ot_layout_table_find_script:
477 * @face: #hb_face_t to work upon
478 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
479 * @script_tag: #hb_tag_t of the script tag requested
480 * @script_index: (out): The index of the requested script tag
481 *
482 * Fetches the index if a given script tag in the specified face's GSUB table
483 * or GPOS table.
484 *
485 * Return value: true if the script is found, false otherwise
486 *
487 **/
488hb_bool_t
489hb_ot_layout_table_find_script (hb_face_t *face,
490 hb_tag_t table_tag,
491 hb_tag_t script_tag,
492 unsigned int *script_index /* OUT */)
493{
494 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
495 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
496
497 if (g.find_script_index (script_tag, script_index))
498 return true;
499
500 /* try finding 'DFLT' */
501 if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
502 return false;
503
504 /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
505 * including many versions of DejaVu Sans Mono! */
506 if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
507 return false;
508
509 /* try with 'latn'; some old fonts put their features there even though
510 they're really trying to support Thai, for example :( */
511 if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index))
512 return false;
513
514 if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
515 return false;
516}
517
518#ifndef HB_DISABLE_DEPRECATED
519/**
520 * hb_ot_layout_table_choose_script:
521 * @face: #hb_face_t to work upon
522 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
523 * @script_tags: Array of #hb_tag_t script tags
524 * @script_index: (out): The index of the requested script tag
525 * @chosen_script: (out): #hb_tag_t of the script tag requested
526 *
527 * Deprecated since 2.0.0
528 **/
529hb_bool_t
530hb_ot_layout_table_choose_script (hb_face_t *face,
531 hb_tag_t table_tag,
532 const hb_tag_t *script_tags,
533 unsigned int *script_index /* OUT */,
534 hb_tag_t *chosen_script /* OUT */)
535{
536 const hb_tag_t *t;
537 for (t = script_tags; *t; t++);
538 return hb_ot_layout_table_select_script (face, table_tag, t - script_tags, script_tags, script_index, chosen_script);
539}
540#endif
541
542/**
543 * hb_ot_layout_table_select_script:
544 * @face: #hb_face_t to work upon
545 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
546 * @script_count: Number of script tags in the array
547 * @script_tags: Array of #hb_tag_t script tags
548 * @script_index: (out): The index of the requested script
549 * @chosen_script: (out): #hb_tag_t of the requested script
550 *
551 * Since: 2.0.0
552 **/
553hb_bool_t
554hb_ot_layout_table_select_script (hb_face_t *face,
555 hb_tag_t table_tag,
556 unsigned int script_count,
557 const hb_tag_t *script_tags,
558 unsigned int *script_index /* OUT */,
559 hb_tag_t *chosen_script /* OUT */)
560{
561 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
562 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
563 unsigned int i;
564
565 for (i = 0; i < script_count; i++)
566 {
567 if (g.find_script_index (script_tags[i], script_index))
568 {
569 if (chosen_script)
570 *chosen_script = script_tags[i];
571 return true;
572 }
573 }
574
575 /* try finding 'DFLT' */
576 if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
577 if (chosen_script)
578 *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
579 return false;
580 }
581
582 /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
583 if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
584 if (chosen_script)
585 *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
586 return false;
587 }
588
589 /* try with 'latn'; some old fonts put their features there even though
590 they're really trying to support Thai, for example :( */
591 if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
592 if (chosen_script)
593 *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
594 return false;
595 }
596
597 if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
598 if (chosen_script)
599 *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
600 return false;
601}
602
603
604/**
605 * hb_ot_layout_table_get_feature_tags:
606 * @face: #hb_face_t to work upon
607 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
608 * @start_offset: offset of the first feature tag to retrieve
609 * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
610 * Output = the actual number of feature tags returned (may be zero)
611 * @feature_tags: (out) (array length=feature_count): Array of feature tags found in the table
612 *
613 * Fetches a list of all feature tags in the given face's GSUB or GPOS table.
614 *
615 **/
616unsigned int
617hb_ot_layout_table_get_feature_tags (hb_face_t *face,
618 hb_tag_t table_tag,
619 unsigned int start_offset,
620 unsigned int *feature_count /* IN/OUT */,
621 hb_tag_t *feature_tags /* OUT */)
622{
623 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
624
625 return g.get_feature_tags (start_offset, feature_count, feature_tags);
626}
627
628
629/**
630 * hb_ot_layout_table_find_feature:
631 * @face: #hb_face_t to work upon
632 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
633 * @feature_tag: The #hb_tag_t og the requested feature tag
634 * @feature_index: (out): The index of the requested feature
635 *
636 * Fetches the index for a given feature tag in the specified face's GSUB table
637 * or GPOS table.
638 *
639 * Return value: true if the feature is found, false otherwise
640 **/
641bool
642hb_ot_layout_table_find_feature (hb_face_t *face,
643 hb_tag_t table_tag,
644 hb_tag_t feature_tag,
645 unsigned int *feature_index /* OUT */)
646{
647 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
648 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
649
650 unsigned int num_features = g.get_feature_count ();
651 for (unsigned int i = 0; i < num_features; i++)
652 {
653 if (feature_tag == g.get_feature_tag (i)) {
654 if (feature_index) *feature_index = i;
655 return true;
656 }
657 }
658
659 if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
660 return false;
661}
662
663
664/**
665 * hb_ot_layout_script_get_language_tags:
666 * @face: #hb_face_t to work upon
667 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
668 * @script_index: The index of the requested script tag
669 * @start_offset: offset of the first language tag to retrieve
670 * @language_count: (inout) (allow-none): Input = the maximum number of language tags to return;
671 * Output = the actual number of language tags returned (may be zero)
672 * @language_tags: (out) (array length=language_count): Array of language tags found in the table
673 *
674 * Fetches a list of language tags in the given face's GSUB or GPOS table, underneath
675 * the specified script index. The list returned will begin at the offset provided.
676 *
677 **/
678unsigned int
679hb_ot_layout_script_get_language_tags (hb_face_t *face,
680 hb_tag_t table_tag,
681 unsigned int script_index,
682 unsigned int start_offset,
683 unsigned int *language_count /* IN/OUT */,
684 hb_tag_t *language_tags /* OUT */)
685{
686 const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
687
688 return s.get_lang_sys_tags (start_offset, language_count, language_tags);
689}
690
691
692#ifndef HB_DISABLE_DEPRECATED
693/**
694 * hb_ot_layout_script_find_language:
695 * @face: #hb_face_t to work upon
696 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
697 * @script_index: The index of the requested script tag
698 * @language_tag: The #hb_tag_t of the requested language
699 * @language_index: The index of the requested language
700 *
701 * Fetches the index of a given language tag in the specified face's GSUB table
702 * or GPOS table, underneath the specified script tag.
703 *
704 * Return value: true if the language tag is found, false otherwise
705 *
706 * Since: ??
707 * Deprecated: ??
708 **/
709hb_bool_t
710hb_ot_layout_script_find_language (hb_face_t *face,
711 hb_tag_t table_tag,
712 unsigned int script_index,
713 hb_tag_t language_tag,
714 unsigned int *language_index)
715{
716 return hb_ot_layout_script_select_language (face,
717 table_tag,
718 script_index,
719 1,
720 &language_tag,
721 language_index);
722}
723#endif
724
725
726/**
727 * hb_ot_layout_script_select_language:
728 * @face: #hb_face_t to work upon
729 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
730 * @script_index: The index of the requested script tag
731 * @language_count: The number of languages in the specified script
732 * @language_tags: The array of language tags
733 * @language_index: (out): The index of the requested language
734 *
735 * Fetches the index of a given language tag in the specified face's GSUB table
736 * or GPOS table, underneath the specified script index.
737 *
738 * Return value: true if the language tag is found, false otherwise
739 *
740 * Since: 2.0.0
741 **/
742hb_bool_t
743hb_ot_layout_script_select_language (hb_face_t *face,
744 hb_tag_t table_tag,
745 unsigned int script_index,
746 unsigned int language_count,
747 const hb_tag_t *language_tags,
748 unsigned int *language_index /* OUT */)
749{
750 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX), "");
751 const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
752 unsigned int i;
753
754 for (i = 0; i < language_count; i++)
755 {
756 if (s.find_lang_sys_index (language_tags[i], language_index))
757 return true;
758 }
759
760 /* try finding 'dflt' */
761 if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
762 return false;
763
764 if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
765 return false;
766}
767
768
769/**
770 * hb_ot_layout_language_get_required_feature_index:
771 * @face: #hb_face_t to work upon
772 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
773 * @script_index: The index of the requested script tag
774 * @language_index: The index of the requested language tag
775 * @feature_index: (out): The index of the requested feature
776 *
777 * Fetches the index of a requested feature in the given face's GSUB or GPOS table,
778 * underneath the specified script and language.
779 *
780 * Return value: true if the feature is found, false otherwise
781 *
782 **/
783hb_bool_t
784hb_ot_layout_language_get_required_feature_index (hb_face_t *face,
785 hb_tag_t table_tag,
786 unsigned int script_index,
787 unsigned int language_index,
788 unsigned int *feature_index)
789{
790 return hb_ot_layout_language_get_required_feature (face,
791 table_tag,
792 script_index,
793 language_index,
794 feature_index,
795 nullptr);
796}
797
798
799/**
800 * hb_ot_layout_language_get_required_feature:
801 * @face: #hb_face_t to work upon
802 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
803 * @script_index: The index of the requested script tag
804 * @language_index: The index of the requested language tag
805 * @feature_index: The index of the requested feature
806 * @feature_tag: (out): The #hb_tag_t of the requested feature
807 *
808 * Fetches the tag of a requested feature index in the given face's GSUB or GPOS table,
809 * underneath the specified script and language.
810 *
811 * Return value: true if the feature is found, false otherwise
812 *
813 * Since: 0.9.30
814 **/
815hb_bool_t
816hb_ot_layout_language_get_required_feature (hb_face_t *face,
817 hb_tag_t table_tag,
818 unsigned int script_index,
819 unsigned int language_index,
820 unsigned int *feature_index,
821 hb_tag_t *feature_tag)
822{
823 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
824 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
825
826 unsigned int index = l.get_required_feature_index ();
827 if (feature_index) *feature_index = index;
828 if (feature_tag) *feature_tag = g.get_feature_tag (index);
829
830 return l.has_required_feature ();
831}
832
833
834/**
835 * hb_ot_layout_language_get_feature_indexes:
836 * @face: #hb_face_t to work upon
837 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
838 * @script_index: The index of the requested script tag
839 * @language_index: The index of the requested language tag
840 * @start_offset: offset of the first feature tag to retrieve
841 * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
842 * Output: the actual number of feature tags returned (may be zero)
843 * @feature_indexes: (out) (array length=feature_count): The array of feature indexes found for the query
844 *
845 * Fetches a list of all features in the specified face's GSUB table
846 * or GPOS table, underneath the specified script and language. The list
847 * returned will begin at the offset provided.
848 **/
849unsigned int
850hb_ot_layout_language_get_feature_indexes (hb_face_t *face,
851 hb_tag_t table_tag,
852 unsigned int script_index,
853 unsigned int language_index,
854 unsigned int start_offset,
855 unsigned int *feature_count /* IN/OUT */,
856 unsigned int *feature_indexes /* OUT */)
857{
858 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
859 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
860
861 return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
862}
863
864
865/**
866 * hb_ot_layout_language_get_feature_tags:
867 * @face: #hb_face_t to work upon
868 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
869 * @script_index: The index of the requested script tag
870 * @language_index: The index of the requested language tag
871 * @start_offset: offset of the first feature tag to retrieve
872 * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
873 * Output = the actual number of feature tags returned (may be zero)
874 * @feature_tags: (out) (array length=feature_count): The array of #hb_tag_t feature tags found for the query
875 *
876 * Fetches a list of all features in the specified face's GSUB table
877 * or GPOS table, underneath the specified script and language. The list
878 * returned will begin at the offset provided.
879 *
880 **/
881unsigned int
882hb_ot_layout_language_get_feature_tags (hb_face_t *face,
883 hb_tag_t table_tag,
884 unsigned int script_index,
885 unsigned int language_index,
886 unsigned int start_offset,
887 unsigned int *feature_count /* IN/OUT */,
888 hb_tag_t *feature_tags /* OUT */)
889{
890 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
891 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
892
893 static_assert ((sizeof (unsigned int) == sizeof (hb_tag_t)), "");
894 unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
895
896 if (feature_tags) {
897 unsigned int count = *feature_count;
898 for (unsigned int i = 0; i < count; i++)
899 feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
900 }
901
902 return ret;
903}
904
905
906/**
907 * hb_ot_layout_language_find_feature:
908 * @face: #hb_face_t to work upon
909 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
910 * @script_index: The index of the requested script tag
911 * @language_index: The index of the requested language tag
912 * @feature_tag: #hb_tag_t of the feature tag requested
913 * @feature_index: (out): The index of the requested feature
914 *
915 * Fetches the index of a given feature tag in the specified face's GSUB table
916 * or GPOS table, underneath the specified script and language.
917 *
918 * Return value: true if the feature is found, false otherwise
919 *
920 **/
921hb_bool_t
922hb_ot_layout_language_find_feature (hb_face_t *face,
923 hb_tag_t table_tag,
924 unsigned int script_index,
925 unsigned int language_index,
926 hb_tag_t feature_tag,
927 unsigned int *feature_index /* OUT */)
928{
929 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
930 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
931 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
932
933 unsigned int num_features = l.get_feature_count ();
934 for (unsigned int i = 0; i < num_features; i++) {
935 unsigned int f_index = l.get_feature_index (i);
936
937 if (feature_tag == g.get_feature_tag (f_index)) {
938 if (feature_index) *feature_index = f_index;
939 return true;
940 }
941 }
942
943 if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
944 return false;
945}
946
947
948/**
949 * hb_ot_layout_feature_get_lookups:
950 * @face: #hb_face_t to work upon
951 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
952 * @feature_index: The index of the requested feature
953 * @start_offset: offset of the first lookup to retrieve
954 * @lookup_count: (inout) (allow-none): Input = the maximum number of lookups to return;
955 * Output = the actual number of lookups returned (may be zero)
956 * @lookup_indexes: (out) (array length=lookup_count): The array of lookup indexes found for the query
957 *
958 * Fetches a list of all lookups enumerated for the specified feature, in
959 * the specified face's GSUB table or GPOS table. The list returned will
960 * begin at the offset provided.
961 *
962 * Since: 0.9.7
963 **/
964unsigned int
965hb_ot_layout_feature_get_lookups (hb_face_t *face,
966 hb_tag_t table_tag,
967 unsigned int feature_index,
968 unsigned int start_offset,
969 unsigned int *lookup_count /* IN/OUT */,
970 unsigned int *lookup_indexes /* OUT */)
971{
972 return hb_ot_layout_feature_with_variations_get_lookups (face,
973 table_tag,
974 feature_index,
975 HB_OT_LAYOUT_NO_VARIATIONS_INDEX,
976 start_offset,
977 lookup_count,
978 lookup_indexes);
979}
980
981
982/**
983 * hb_ot_layout_table_get_lookup_count:
984 * @face: #hb_face_t to work upon
985 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
986 *
987 * Fetches the total number of lookups enumerated in the specified
988 * face's GSUB table or GPOS table.
989 *
990 * Since: 0.9.22
991 **/
992unsigned int
993hb_ot_layout_table_get_lookup_count (hb_face_t *face,
994 hb_tag_t table_tag)
995{
996 return get_gsubgpos_table (face, table_tag).get_lookup_count ();
997}
998
999
1000struct hb_collect_features_context_t
1001{
1002 hb_collect_features_context_t (hb_face_t *face,
1003 hb_tag_t table_tag,
1004 hb_set_t *feature_indexes_)
1005 : g (get_gsubgpos_table (face, table_tag)),
1006 feature_indexes (feature_indexes_),
1007 script_count(0),langsys_count(0) {}
1008
1009 bool visited (const OT::Script &s)
1010 {
1011 /* We might have Null() object here. Don't want to involve
1012 * that in the memoize. So, detect empty objects and return. */
1013 if (unlikely (!s.has_default_lang_sys () &&
1014 !s.get_lang_sys_count ()))
1015 return true;
1016
1017 if (script_count++ > HB_MAX_SCRIPTS)
1018 return true;
1019
1020 return visited (s, visited_script);
1021 }
1022 bool visited (const OT::LangSys &l)
1023 {
1024 /* We might have Null() object here. Don't want to involve
1025 * that in the memoize. So, detect empty objects and return. */
1026 if (unlikely (!l.has_required_feature () &&
1027 !l.get_feature_count ()))
1028 return true;
1029
1030 if (langsys_count++ > HB_MAX_LANGSYS)
1031 return true;
1032
1033 return visited (l, visited_langsys);
1034 }
1035
1036 private:
1037 template <typename T>
1038 bool visited (const T &p, hb_set_t &visited_set)
1039 {
1040 hb_codepoint_t delta = (hb_codepoint_t) ((uintptr_t) &p - (uintptr_t) &g);
1041 if (visited_set.has (delta))
1042 return true;
1043
1044 visited_set.add (delta);
1045 return false;
1046 }
1047
1048 public:
1049 const OT::GSUBGPOS &g;
1050 hb_set_t *feature_indexes;
1051
1052 private:
1053 hb_set_t visited_script;
1054 hb_set_t visited_langsys;
1055 unsigned int script_count;
1056 unsigned int langsys_count;
1057};
1058
1059static void
1060langsys_collect_features (hb_collect_features_context_t *c,
1061 const OT::LangSys &l,
1062 const hb_tag_t *features)
1063{
1064 if (c->visited (l)) return;
1065
1066 if (!features)
1067 {
1068 /* All features. */
1069 if (l.has_required_feature ())
1070 c->feature_indexes->add (l.get_required_feature_index ());
1071
1072 l.add_feature_indexes_to (c->feature_indexes);
1073 }
1074 else
1075 {
1076 /* Ugh. Any faster way? */
1077 for (; *features; features++)
1078 {
1079 hb_tag_t feature_tag = *features;
1080 unsigned int num_features = l.get_feature_count ();
1081 for (unsigned int i = 0; i < num_features; i++)
1082 {
1083 unsigned int feature_index = l.get_feature_index (i);
1084
1085 if (feature_tag == c->g.get_feature_tag (feature_index))
1086 {
1087 c->feature_indexes->add (feature_index);
1088 break;
1089 }
1090 }
1091 }
1092 }
1093}
1094
1095static void
1096script_collect_features (hb_collect_features_context_t *c,
1097 const OT::Script &s,
1098 const hb_tag_t *languages,
1099 const hb_tag_t *features)
1100{
1101 if (c->visited (s)) return;
1102
1103 if (!languages)
1104 {
1105 /* All languages. */
1106 if (s.has_default_lang_sys ())
1107 langsys_collect_features (c,
1108 s.get_default_lang_sys (),
1109 features);
1110
1111 unsigned int count = s.get_lang_sys_count ();
1112 for (unsigned int language_index = 0; language_index < count; language_index++)
1113 langsys_collect_features (c,
1114 s.get_lang_sys (language_index),
1115 features);
1116 }
1117 else
1118 {
1119 for (; *languages; languages++)
1120 {
1121 unsigned int language_index;
1122 if (s.find_lang_sys_index (*languages, &language_index))
1123 langsys_collect_features (c,
1124 s.get_lang_sys (language_index),
1125 features);
1126 }
1127 }
1128}
1129
1130
1131/**
1132 * hb_ot_layout_collect_features:
1133 * @face: #hb_face_t to work upon
1134 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
1135 * @scripts: The array of scripts to collect features for
1136 * @languages: The array of languages to collect features for
1137 * @features: The array of features to collect
1138 * @feature_indexes: (out): The array of feature indexes found for the query
1139 *
1140 * Fetches a list of all feature indexes in the specified face's GSUB table
1141 * or GPOS table, underneath the specified scripts, languages, and features.
1142 * If no list of scripts is provided, all scripts will be queried. If no list
1143 * of languages is provided, all languages will be queried. If no list of
1144 * features is provided, all features will be queried.
1145 *
1146 * Since: 1.8.5
1147 **/
1148void
1149hb_ot_layout_collect_features (hb_face_t *face,
1150 hb_tag_t table_tag,
1151 const hb_tag_t *scripts,
1152 const hb_tag_t *languages,
1153 const hb_tag_t *features,
1154 hb_set_t *feature_indexes /* OUT */)
1155{
1156 hb_collect_features_context_t c (face, table_tag, feature_indexes);
1157 if (!scripts)
1158 {
1159 /* All scripts. */
1160 unsigned int count = c.g.get_script_count ();
1161 for (unsigned int script_index = 0; script_index < count; script_index++)
1162 script_collect_features (&c,
1163 c.g.get_script (script_index),
1164 languages,
1165 features);
1166 }
1167 else
1168 {
1169 for (; *scripts; scripts++)
1170 {
1171 unsigned int script_index;
1172 if (c.g.find_script_index (*scripts, &script_index))
1173 script_collect_features (&c,
1174 c.g.get_script (script_index),
1175 languages,
1176 features);
1177 }
1178 }
1179}
1180
1181
1182/**
1183 * hb_ot_layout_collect_lookups:
1184 * @face: #hb_face_t to work upon
1185 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
1186 * @scripts: The array of scripts to collect lookups for
1187 * @languages: The array of languages to collect lookups for
1188 * @features: The array of features to collect lookups for
1189 * @lookup_indexes: (out): The array of lookup indexes found for the query
1190 *
1191 * Fetches a list of all feature-lookup indexes in the specified face's GSUB
1192 * table or GPOS table, underneath the specified scripts, languages, and
1193 * features. If no list of scripts is provided, all scripts will be queried.
1194 * If no list of languages is provided, all languages will be queried. If no
1195 * list of features is provided, all features will be queried.
1196 *
1197 * Since: 0.9.8
1198 **/
1199void
1200hb_ot_layout_collect_lookups (hb_face_t *face,
1201 hb_tag_t table_tag,
1202 const hb_tag_t *scripts,
1203 const hb_tag_t *languages,
1204 const hb_tag_t *features,
1205 hb_set_t *lookup_indexes /* OUT */)
1206{
1207 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1208
1209 hb_set_t feature_indexes;
1210 hb_ot_layout_collect_features (face, table_tag, scripts, languages, features, &feature_indexes);
1211
1212 for (hb_codepoint_t feature_index = HB_SET_VALUE_INVALID;
1213 hb_set_next (&feature_indexes, &feature_index);)
1214 g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes);
1215}
1216
1217
1218#ifndef HB_NO_LAYOUT_COLLECT_GLYPHS
1219/**
1220 * hb_ot_layout_lookup_collect_glyphs:
1221 * @face: #hb_face_t to work upon
1222 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
1223 * @lookup_index: The index of the feature lookup to query
1224 * @glyphs_before: (out): Array of glyphs preceding the substitution range
1225 * @glyphs_input: (out): Array of input glyphs that would be substituted by the lookup
1226 * @glyphs_after: (out): Array of glyphs following the substition range
1227 * @glyphs_output: (out): Array of glyphs that would be the substitued output of the lookup
1228 *
1229 * Fetches a list of all glyphs affected by the specified lookup in the
1230 * specified face's GSUB table or GPOS table.
1231 *
1232 * Since: 0.9.7
1233 **/
1234void
1235hb_ot_layout_lookup_collect_glyphs (hb_face_t *face,
1236 hb_tag_t table_tag,
1237 unsigned int lookup_index,
1238 hb_set_t *glyphs_before, /* OUT. May be NULL */
1239 hb_set_t *glyphs_input, /* OUT. May be NULL */
1240 hb_set_t *glyphs_after, /* OUT. May be NULL */
1241 hb_set_t *glyphs_output /* OUT. May be NULL */)
1242{
1243 OT::hb_collect_glyphs_context_t c (face,
1244 glyphs_before,
1245 glyphs_input,
1246 glyphs_after,
1247 glyphs_output);
1248
1249 switch (table_tag)
1250 {
1251 case HB_OT_TAG_GSUB:
1252 {
1253 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
1254 l.collect_glyphs (&c);
1255 return;
1256 }
1257 case HB_OT_TAG_GPOS:
1258 {
1259 const OT::PosLookup& l = face->table.GPOS->table->get_lookup (lookup_index);
1260 l.collect_glyphs (&c);
1261 return;
1262 }
1263 }
1264}
1265#endif
1266
1267
1268/* Variations support */
1269
1270
1271/**
1272 * hb_ot_layout_table_find_feature_variations:
1273 * @face: #hb_face_t to work upon
1274 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
1275 * @coords: The variation coordinates to query
1276 * @num_coords: The number of variation coorinates
1277 * @variations_index: (out): The array of feature variations found for the query
1278 *
1279 * Fetches a list of feature variations in the specified face's GSUB table
1280 * or GPOS table, at the specified variation coordinates.
1281 *
1282 **/
1283hb_bool_t
1284hb_ot_layout_table_find_feature_variations (hb_face_t *face,
1285 hb_tag_t table_tag,
1286 const int *coords,
1287 unsigned int num_coords,
1288 unsigned int *variations_index /* out */)
1289{
1290 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1291
1292 return g.find_variations_index (coords, num_coords, variations_index);
1293}
1294
1295
1296/**
1297 * hb_ot_layout_feature_with_variations_get_lookups:
1298 * @face: #hb_face_t to work upon
1299 * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
1300 * @feature_index: The index of the feature to query
1301 * @variations_index: The index of the feature variation to query
1302 * @start_offset: offset of the first lookup to retrieve
1303 * @lookup_count: (inout) (allow-none): Input = the maximum number of lookups to return;
1304 * Output = the actual number of lookups returned (may be zero)
1305 * @lookup_indexes: (out) (array length=lookup_count): The array of lookups found for the query
1306 *
1307 * Fetches a list of all lookups enumerated for the specified feature, in
1308 * the specified face's GSUB table or GPOS table, enabled at the specified
1309 * variations index. The list returned will begin at the offset provided.
1310 *
1311 **/
1312unsigned int
1313hb_ot_layout_feature_with_variations_get_lookups (hb_face_t *face,
1314 hb_tag_t table_tag,
1315 unsigned int feature_index,
1316 unsigned int variations_index,
1317 unsigned int start_offset,
1318 unsigned int *lookup_count /* IN/OUT */,
1319 unsigned int *lookup_indexes /* OUT */)
1320{
1321 static_assert ((OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX), "");
1322 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1323
1324 const OT::Feature &f = g.get_feature_variation (feature_index, variations_index);
1325
1326 return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
1327}
1328
1329
1330/*
1331 * OT::GSUB
1332 */
1333
1334
1335/**
1336 * hb_ot_layout_has_substitution:
1337 * @face: #hb_face_t to work upon
1338 *
1339 * Tests whether the specified face includes any GSUB substitutions.
1340 *
1341 * Return value: true if data found, false otherwise
1342 *
1343 **/
1344hb_bool_t
1345hb_ot_layout_has_substitution (hb_face_t *face)
1346{
1347 return face->table.GSUB->table->has_data ();
1348}
1349
1350
1351/**
1352 * hb_ot_layout_lookup_would_substitute:
1353 * @face: #hb_face_t to work upon
1354 * @lookup_index: The index of the lookup to query
1355 * @glyphs: The sequence of glyphs to query for substitution
1356 * @glyphs_length: The length of the glyph sequence
1357 * @zero_context: #hb_bool_t indicating whether substitutions should be context-free
1358 *
1359 * Tests whether a specified lookup in the specified face would
1360 * trigger a substitution on the given glyph sequence.
1361 *
1362 * Return value: true if a substitution would be triggered, false otherwise
1363 *
1364 * Since: 0.9.7
1365 **/
1366hb_bool_t
1367hb_ot_layout_lookup_would_substitute (hb_face_t *face,
1368 unsigned int lookup_index,
1369 const hb_codepoint_t *glyphs,
1370 unsigned int glyphs_length,
1371 hb_bool_t zero_context)
1372{
1373 if (unlikely (lookup_index >= face->table.GSUB->lookup_count)) return false;
1374 OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
1375
1376 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
1377
1378 return l.would_apply (&c, &face->table.GSUB->accels[lookup_index]);
1379}
1380
1381
1382/**
1383 * hb_ot_layout_substitute_start:
1384 * @font: #hb_font_t to use
1385 * @buffer: #hb_buffer_t buffer to work upon
1386 *
1387 * Called before substitution lookups are performed, to ensure that glyph
1388 * class and other properties are set on the glyphs in the buffer.
1389 *
1390 **/
1391void
1392hb_ot_layout_substitute_start (hb_font_t *font,
1393 hb_buffer_t *buffer)
1394{
1395_hb_ot_layout_set_glyph_props (font, buffer);
1396}
1397
1398void
1399hb_ot_layout_delete_glyphs_inplace (hb_buffer_t *buffer,
1400 bool (*filter) (const hb_glyph_info_t *info))
1401{
1402 /* Merge clusters and delete filtered glyphs.
1403 * NOTE! We can't use out-buffer as we have positioning data. */
1404 unsigned int j = 0;
1405 unsigned int count = buffer->len;
1406 hb_glyph_info_t *info = buffer->info;
1407 hb_glyph_position_t *pos = buffer->pos;
1408 for (unsigned int i = 0; i < count; i++)
1409 {
1410 if (filter (&info[i]))
1411 {
1412 /* Merge clusters.
1413 * Same logic as buffer->delete_glyph(), but for in-place removal. */
1414
1415 unsigned int cluster = info[i].cluster;
1416 if (i + 1 < count && cluster == info[i + 1].cluster)
1417 continue; /* Cluster survives; do nothing. */
1418
1419 if (j)
1420 {
1421 /* Merge cluster backward. */
1422 if (cluster < info[j - 1].cluster)
1423 {
1424 unsigned int mask = info[i].mask;
1425 unsigned int old_cluster = info[j - 1].cluster;
1426 for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
1427 buffer->set_cluster (info[k - 1], cluster, mask);
1428 }
1429 continue;
1430 }
1431
1432 if (i + 1 < count)
1433 buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */
1434
1435 continue;
1436 }
1437
1438 if (j != i)
1439 {
1440 info[j] = info[i];
1441 pos[j] = pos[i];
1442 }
1443 j++;
1444 }
1445 buffer->len = j;
1446}
1447
1448/**
1449 * hb_ot_layout_lookup_substitute_closure:
1450 * @face: #hb_face_t to work upon
1451 * @lookup_index: index of the feature lookup to query
1452 * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookup
1453 *
1454 * Compute the transitive closure of glyphs needed for a
1455 * specified lookup.
1456 *
1457 * Since: 0.9.7
1458 **/
1459void
1460hb_ot_layout_lookup_substitute_closure (hb_face_t *face,
1461 unsigned int lookup_index,
1462 hb_set_t *glyphs /* OUT */)
1463{
1464 hb_map_t done_lookups;
1465 OT::hb_closure_context_t c (face, glyphs, &done_lookups);
1466
1467 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
1468
1469 l.closure (&c, lookup_index);
1470}
1471
1472/**
1473 * hb_ot_layout_lookups_substitute_closure:
1474 * @face: #hb_face_t to work upon
1475 * @lookups: The set of lookups to query
1476 * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookups
1477 *
1478 * Compute the transitive closure of glyphs needed for all of the
1479 * provided lookups.
1480 *
1481 * Since: 1.8.1
1482 **/
1483void
1484hb_ot_layout_lookups_substitute_closure (hb_face_t *face,
1485 const hb_set_t *lookups,
1486 hb_set_t *glyphs /* OUT */)
1487{
1488 hb_map_t done_lookups;
1489 OT::hb_closure_context_t c (face, glyphs, &done_lookups);
1490 const OT::GSUB& gsub = *face->table.GSUB->table;
1491
1492 unsigned int iteration_count = 0;
1493 unsigned int glyphs_length;
1494 do
1495 {
1496 glyphs_length = glyphs->get_population ();
1497 if (lookups != nullptr)
1498 {
1499 for (hb_codepoint_t lookup_index = HB_SET_VALUE_INVALID; hb_set_next (lookups, &lookup_index);)
1500 gsub.get_lookup (lookup_index).closure (&c, lookup_index);
1501 }
1502 else
1503 {
1504 for (unsigned int i = 0; i < gsub.get_lookup_count (); i++)
1505 gsub.get_lookup (i).closure (&c, i);
1506 }
1507 } while (iteration_count++ <= HB_CLOSURE_MAX_STAGES &&
1508 glyphs_length != glyphs->get_population ());
1509}
1510
1511/*
1512 * OT::GPOS
1513 */
1514
1515
1516/**
1517 * hb_ot_layout_has_positioning:
1518 * @face: #hb_face_t to work upon
1519 *
1520 * Return value: true if the face has GPOS data, false otherwise
1521 *
1522 **/
1523hb_bool_t
1524hb_ot_layout_has_positioning (hb_face_t *face)
1525{
1526 return face->table.GPOS->table->has_data ();
1527}
1528
1529/**
1530 * hb_ot_layout_position_start:
1531 * @font: #hb_font_t to use
1532 * @buffer: #hb_buffer_t buffer to work upon
1533 *
1534 * Called before positioning lookups are performed, to ensure that glyph
1535 * attachment types and glyph-attachment chains are set for the glyphs in the buffer.
1536 *
1537 **/
1538void
1539hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
1540{
1541 OT::GPOS::position_start (font, buffer);
1542}
1543
1544
1545/**
1546 * hb_ot_layout_position_finish_advances:
1547 * @font: #hb_font_t to use
1548 * @buffer: #hb_buffer_t buffer to work upon
1549 *
1550 * Called after positioning lookups are performed, to finish glyph advances.
1551 *
1552 **/
1553void
1554hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
1555{
1556 OT::GPOS::position_finish_advances (font, buffer);
1557}
1558
1559/**
1560 * hb_ot_layout_position_finish_offsets:
1561 * @font: #hb_font_t to use
1562 * @buffer: #hb_buffer_t buffer to work upon
1563 *
1564 * Called after positioning lookups are performed, to finish glyph offsets.
1565 *
1566 **/
1567void
1568hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
1569{
1570 OT::GPOS::position_finish_offsets (font, buffer);
1571}
1572
1573
1574#ifndef HB_NO_LAYOUT_FEATURE_PARAMS
1575/**
1576 * hb_ot_layout_get_size_params:
1577 * @face: #hb_face_t to work upon
1578 * @design_size: (out): The design size of the face
1579 * @subfamily_id: (out): The identifier of the face within the font subfamily
1580 * @subfamily_name_id: (out): The ‘name’ table name ID of the face within the font subfamily
1581 * @range_start: (out): The minimum size of the recommended size range for the face
1582 * @range_end: (out): The maximum size of the recommended size range for the face
1583 *
1584 * Fetches optical-size feature data (i.e., the `size` feature from GPOS). Note that
1585 * the subfamily_id and the subfamily name string (accessible via the subfamily_name_id)
1586 * as used here are defined as pertaining only to fonts within a font family that differ
1587 * specifically in their respective size ranges; other ways to differentiate fonts within
1588 * a subfamily are not covered by the `size` feature.
1589 *
1590 * For more information on this distinction, see the `size` documentation at
1591 * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-39size39
1592 *
1593 * Return value: true if data found, false otherwise
1594 *
1595 * Since: 0.9.10
1596 **/
1597hb_bool_t
1598hb_ot_layout_get_size_params (hb_face_t *face,
1599 unsigned int *design_size, /* OUT. May be NULL */
1600 unsigned int *subfamily_id, /* OUT. May be NULL */
1601 hb_ot_name_id_t *subfamily_name_id, /* OUT. May be NULL */
1602 unsigned int *range_start, /* OUT. May be NULL */
1603 unsigned int *range_end /* OUT. May be NULL */)
1604{
1605 const OT::GPOS &gpos = *face->table.GPOS->table;
1606 const hb_tag_t tag = HB_TAG ('s','i','z','e');
1607
1608 unsigned int num_features = gpos.get_feature_count ();
1609 for (unsigned int i = 0; i < num_features; i++)
1610 {
1611 if (tag == gpos.get_feature_tag (i))
1612 {
1613 const OT::Feature &f = gpos.get_feature (i);
1614 const OT::FeatureParamsSize &params = f.get_feature_params ().get_size_params (tag);
1615
1616 if (params.designSize)
1617 {
1618 if (design_size) *design_size = params.designSize;
1619 if (subfamily_id) *subfamily_id = params.subfamilyID;
1620 if (subfamily_name_id) *subfamily_name_id = params.subfamilyNameID;
1621 if (range_start) *range_start = params.rangeStart;
1622 if (range_end) *range_end = params.rangeEnd;
1623
1624 return true;
1625 }
1626 }
1627 }
1628
1629 if (design_size) *design_size = 0;
1630 if (subfamily_id) *subfamily_id = 0;
1631 if (subfamily_name_id) *subfamily_name_id = HB_OT_NAME_ID_INVALID;
1632 if (range_start) *range_start = 0;
1633 if (range_end) *range_end = 0;
1634
1635 return false;
1636}
1637/**
1638 * hb_ot_layout_feature_get_name_ids:
1639 * @face: #hb_face_t to work upon
1640 * @table_tag: table tag to query, "GSUB" or "GPOS".
1641 * @feature_index: index of feature to query.
1642 * @label_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
1643 * for a user-interface label for this feature. (May be NULL.)
1644 * @tooltip_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
1645 * that an application can use for tooltip text for this
1646 * feature. (May be NULL.)
1647 * @sample_id: (out) (allow-none): The ‘name’ table name ID that specifies sample text
1648 * that illustrates the effect of this feature. (May be NULL.)
1649 * @num_named_parameters: (out) (allow-none): Number of named parameters. (May be zero.)
1650 * @first_param_id: (out) (allow-none): The first ‘name’ table name ID used to specify
1651 * strings for user-interface labels for the feature
1652 * parameters. (Must be zero if numParameters is zero.)
1653 *
1654 * Fetches name indices from feature parameters for "Stylistic Set" ('ssXX') or
1655 * "Character Variant" ('cvXX') features.
1656 *
1657 * Return value: true if data found, false otherwise
1658 *
1659 * Since: 2.0.0
1660 **/
1661hb_bool_t
1662hb_ot_layout_feature_get_name_ids (hb_face_t *face,
1663 hb_tag_t table_tag,
1664 unsigned int feature_index,
1665 hb_ot_name_id_t *label_id, /* OUT. May be NULL */
1666 hb_ot_name_id_t *tooltip_id, /* OUT. May be NULL */
1667 hb_ot_name_id_t *sample_id, /* OUT. May be NULL */
1668 unsigned int *num_named_parameters, /* OUT. May be NULL */
1669 hb_ot_name_id_t *first_param_id /* OUT. May be NULL */)
1670{
1671 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1672
1673 hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1674 const OT::Feature &f = g.get_feature (feature_index);
1675
1676 const OT::FeatureParams &feature_params = f.get_feature_params ();
1677 if (&feature_params != &Null (OT::FeatureParams))
1678 {
1679 const OT::FeatureParamsStylisticSet& ss_params =
1680 feature_params.get_stylistic_set_params (feature_tag);
1681 if (&ss_params != &Null (OT::FeatureParamsStylisticSet)) /* ssXX */
1682 {
1683 if (label_id) *label_id = ss_params.uiNameID;
1684 // ssXX features don't have the rest
1685 if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1686 if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1687 if (num_named_parameters) *num_named_parameters = 0;
1688 if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1689 return true;
1690 }
1691 const OT::FeatureParamsCharacterVariants& cv_params =
1692 feature_params.get_character_variants_params (feature_tag);
1693 if (&cv_params != &Null (OT::FeatureParamsCharacterVariants)) /* cvXX */
1694 {
1695 if (label_id) *label_id = cv_params.featUILableNameID;
1696 if (tooltip_id) *tooltip_id = cv_params.featUITooltipTextNameID;
1697 if (sample_id) *sample_id = cv_params.sampleTextNameID;
1698 if (num_named_parameters) *num_named_parameters = cv_params.numNamedParameters;
1699 if (first_param_id) *first_param_id = cv_params.firstParamUILabelNameID;
1700 return true;
1701 }
1702 }
1703
1704 if (label_id) *label_id = HB_OT_NAME_ID_INVALID;
1705 if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1706 if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1707 if (num_named_parameters) *num_named_parameters = 0;
1708 if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1709 return false;
1710}
1711/**
1712 * hb_ot_layout_feature_get_characters:
1713 * @face: #hb_face_t to work upon
1714 * @table_tag: table tag to query, "GSUB" or "GPOS".
1715 * @feature_index: index of feature to query.
1716 * @start_offset: offset of the first character to retrieve
1717 * @char_count: (inout) (allow-none): Input = the maximum number of characters to return;
1718 * Output = the actual number of characters returned (may be zero)
1719 * @characters: (out caller-allocates) (array length=char_count): A buffer pointer.
1720 * The Unicode codepoints of the characters for which this feature provides
1721 * glyph variants.
1722 *
1723 * Fetches a list of the characters defined as having a variant under the specified
1724 * "Character Variant" ("cvXX") feature tag.
1725 *
1726 * <note>Note: If the char_count output value is equal to its input value, then there
1727 * is a chance there were more characters defined under the feature tag than were
1728 * returned. This function can be called with incrementally larger start_offset
1729 * until the char_count output value is lower than its input value, or the size
1730 * of the characters array can be increased.</note>
1731 *
1732 * Return value: Number of total sample characters in the cvXX feature.
1733 *
1734 * Since: 2.0.0
1735 **/
1736unsigned int
1737hb_ot_layout_feature_get_characters (hb_face_t *face,
1738 hb_tag_t table_tag,
1739 unsigned int feature_index,
1740 unsigned int start_offset,
1741 unsigned int *char_count, /* IN/OUT. May be NULL */
1742 hb_codepoint_t *characters /* OUT. May be NULL */)
1743{
1744 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1745
1746 hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1747 const OT::Feature &f = g.get_feature (feature_index);
1748
1749 const OT::FeatureParams &feature_params = f.get_feature_params ();
1750
1751 const OT::FeatureParamsCharacterVariants& cv_params =
1752 feature_params.get_character_variants_params(feature_tag);
1753
1754 unsigned int len = 0;
1755 if (char_count && characters && start_offset < cv_params.characters.len)
1756 {
1757 len = hb_min (cv_params.characters.len - start_offset, *char_count);
1758 for (unsigned int i = 0; i < len; ++i)
1759 characters[i] = cv_params.characters[start_offset + i];
1760 }
1761 if (char_count) *char_count = len;
1762 return cv_params.characters.len;
1763}
1764#endif
1765
1766
1767/*
1768 * Parts of different types are implemented here such that they have direct
1769 * access to GSUB/GPOS lookups.
1770 */
1771
1772
1773struct GSUBProxy
1774{
1775 static constexpr unsigned table_index = 0u;
1776 static constexpr bool inplace = false;
1777 typedef OT::SubstLookup Lookup;
1778
1779 GSUBProxy (hb_face_t *face) :
1780 table (*face->table.GSUB->table),
1781 accels (face->table.GSUB->accels) {}
1782
1783 const OT::GSUB &table;
1784 const OT::hb_ot_layout_lookup_accelerator_t *accels;
1785};
1786
1787struct GPOSProxy
1788{
1789 static constexpr unsigned table_index = 1u;
1790 static constexpr bool inplace = true;
1791 typedef OT::PosLookup Lookup;
1792
1793 GPOSProxy (hb_face_t *face) :
1794 table (*face->table.GPOS->table),
1795 accels (face->table.GPOS->accels) {}
1796
1797 const OT::GPOS &table;
1798 const OT::hb_ot_layout_lookup_accelerator_t *accels;
1799};
1800
1801
1802static inline bool
1803apply_forward (OT::hb_ot_apply_context_t *c,
1804 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1805{
1806 bool ret = false;
1807 hb_buffer_t *buffer = c->buffer;
1808 while (buffer->idx < buffer->len && buffer->successful)
1809 {
1810 bool applied = false;
1811 if (accel.may_have (buffer->cur().codepoint) &&
1812 (buffer->cur().mask & c->lookup_mask) &&
1813 c->check_glyph_property (&buffer->cur(), c->lookup_props))
1814 {
1815 applied = accel.apply (c);
1816 }
1817
1818 if (applied)
1819 ret = true;
1820 else
1821 buffer->next_glyph ();
1822 }
1823 return ret;
1824}
1825
1826static inline bool
1827apply_backward (OT::hb_ot_apply_context_t *c,
1828 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1829{
1830 bool ret = false;
1831 hb_buffer_t *buffer = c->buffer;
1832 do
1833 {
1834 if (accel.may_have (buffer->cur().codepoint) &&
1835 (buffer->cur().mask & c->lookup_mask) &&
1836 c->check_glyph_property (&buffer->cur(), c->lookup_props))
1837 ret |= accel.apply (c);
1838
1839 /* The reverse lookup doesn't "advance" cursor (for good reason). */
1840 buffer->idx--;
1841
1842 }
1843 while ((int) buffer->idx >= 0);
1844 return ret;
1845}
1846
1847template <typename Proxy>
1848static inline void
1849apply_string (OT::hb_ot_apply_context_t *c,
1850 const typename Proxy::Lookup &lookup,
1851 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1852{
1853 hb_buffer_t *buffer = c->buffer;
1854
1855 if (unlikely (!buffer->len || !c->lookup_mask))
1856 return;
1857
1858 c->set_lookup_props (lookup.get_props ());
1859
1860 if (likely (!lookup.is_reverse ()))
1861 {
1862 /* in/out forward substitution/positioning */
1863 if (Proxy::table_index == 0u)
1864 buffer->clear_output ();
1865 buffer->idx = 0;
1866
1867 bool ret;
1868 ret = apply_forward (c, accel);
1869 if (ret)
1870 {
1871 if (!Proxy::inplace)
1872 buffer->swap_buffers ();
1873 else
1874 assert (!buffer->has_separate_output ());
1875 }
1876 }
1877 else
1878 {
1879 /* in-place backward substitution/positioning */
1880 if (Proxy::table_index == 0u)
1881 buffer->remove_output ();
1882 buffer->idx = buffer->len - 1;
1883
1884 apply_backward (c, accel);
1885 }
1886}
1887
1888template <typename Proxy>
1889inline void hb_ot_map_t::apply (const Proxy &proxy,
1890 const hb_ot_shape_plan_t *plan,
1891 hb_font_t *font,
1892 hb_buffer_t *buffer) const
1893{
1894 const unsigned int table_index = proxy.table_index;
1895 unsigned int i = 0;
1896 OT::hb_ot_apply_context_t c (table_index, font, buffer);
1897 c.set_recurse_func (Proxy::Lookup::apply_recurse_func);
1898
1899 for (unsigned int stage_index = 0; stage_index < stages[table_index].length; stage_index++) {
1900 const stage_map_t *stage = &stages[table_index][stage_index];
1901 for (; i < stage->last_lookup; i++)
1902 {
1903 unsigned int lookup_index = lookups[table_index][i].index;
1904 if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
1905 c.set_lookup_index (lookup_index);
1906 c.set_lookup_mask (lookups[table_index][i].mask);
1907 c.set_auto_zwj (lookups[table_index][i].auto_zwj);
1908 c.set_auto_zwnj (lookups[table_index][i].auto_zwnj);
1909 if (lookups[table_index][i].random)
1910 {
1911 c.set_random (true);
1912 buffer->unsafe_to_break_all ();
1913 }
1914 apply_string<Proxy> (&c,
1915 proxy.table.get_lookup (lookup_index),
1916 proxy.accels[lookup_index]);
1917 (void) buffer->message (font, "end lookup %d", lookup_index);
1918 }
1919
1920 if (stage->pause_func)
1921 {
1922 buffer->clear_output ();
1923 stage->pause_func (plan, font, buffer);
1924 }
1925 }
1926}
1927
1928void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1929{
1930 GSUBProxy proxy (font->face);
1931 apply (proxy, plan, font, buffer);
1932}
1933
1934void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1935{
1936 GPOSProxy proxy (font->face);
1937 apply (proxy, plan, font, buffer);
1938}
1939
1940void
1941hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
1942 const OT::SubstLookup &lookup,
1943 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1944{
1945 apply_string<GSUBProxy> (c, lookup, accel);
1946}
1947
1948#ifndef HB_NO_BASE
1949/**
1950 * hb_ot_layout_get_baseline:
1951 * @font: a font
1952 * @baseline_tag: a baseline tag
1953 * @direction: text direction.
1954 * @script_tag: script tag.
1955 * @language_tag: language tag.
1956 * @coord: (out): baseline value if found.
1957 *
1958 * Fetches a baseline value from the face.
1959 *
1960 * Return value: if found baseline value in the the font.
1961 *
1962 * Since: 2.6.0
1963 **/
1964hb_bool_t
1965hb_ot_layout_get_baseline (hb_font_t *font,
1966 hb_ot_layout_baseline_tag_t baseline_tag,
1967 hb_direction_t direction,
1968 hb_tag_t script_tag,
1969 hb_tag_t language_tag,
1970 hb_position_t *coord /* OUT. May be NULL. */)
1971{
1972 bool result = font->face->table.BASE->get_baseline (font, baseline_tag, direction, script_tag, language_tag, coord);
1973
1974 if (result && coord)
1975 *coord = HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_y (*coord) : font->em_scale_x (*coord);
1976
1977 return result;
1978}
1979#endif
1980#endif
1981