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"
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-morx-table.hh"
55 #include "hb-aat-layout-opbd-table.hh" // Just so we compile it; unused otherwise.
56
57 using OT::Layout::GSUB;
58 using OT::Layout::GPOS;
59
60 /**
61 * SECTION:hb-ot-layout
62 * @title: hb-ot-layout
63 * @short_description: OpenType Layout
64 * @include: hb-ot.h
65 *
66 * Functions for querying OpenType Layout features in the font face.
67 * See the [OpenType specification](http://www.microsoft.com/typography/otspec/)
68 * for details.
69 **/
70
71
72 /*
73 * kern
74 */
75
76 #ifndef HB_NO_OT_KERN
77 /**
78 * hb_ot_layout_has_kerning:
79 * @face: The #hb_face_t to work on
80 *
81 * Tests whether a face includes any kerning data in the 'kern' table.
82 * Does NOT test for kerning lookups in the GPOS table.
83 *
84 * Return value: `true` if data found, `false` otherwise
85 *
86 **/
87 bool
hb_ot_layout_has_kerning(hb_face_t * face)88 hb_ot_layout_has_kerning (hb_face_t *face)
89 {
90 return face->table.kern->table->has_data ();
91 }
92
93 /**
94 * hb_ot_layout_has_machine_kerning:
95 * @face: The #hb_face_t to work on
96 *
97 * Tests whether a face includes any state-machine kerning in the 'kern' table.
98 * Does NOT examine the GPOS table.
99 *
100 * Return value: `true` if data found, `false` otherwise
101 *
102 **/
103 bool
hb_ot_layout_has_machine_kerning(hb_face_t * face)104 hb_ot_layout_has_machine_kerning (hb_face_t *face)
105 {
106 return face->table.kern->table->has_state_machine ();
107 }
108
109 /**
110 * hb_ot_layout_has_cross_kerning:
111 * @face: The #hb_face_t to work on
112 *
113 * Tests whether a face has any cross-stream kerning (i.e., kerns
114 * that make adjustments perpendicular to the direction of the text
115 * flow: Y adjustments in horizontal text or X adjustments in
116 * vertical text) in the 'kern' table.
117 *
118 * Does NOT examine the GPOS table.
119 *
120 * Return value: `true` is data found, `false` otherwise
121 *
122 **/
123 bool
hb_ot_layout_has_cross_kerning(hb_face_t * face)124 hb_ot_layout_has_cross_kerning (hb_face_t *face)
125 {
126 return face->table.kern->table->has_cross_stream ();
127 }
128
129 void
hb_ot_layout_kern(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer)130 hb_ot_layout_kern (const hb_ot_shape_plan_t *plan,
131 hb_font_t *font,
132 hb_buffer_t *buffer)
133 {
134 hb_blob_t *blob = font->face->table.kern.get_blob ();
135 const auto& kern = *font->face->table.kern;
136
137 AAT::hb_aat_apply_context_t c (plan, font, buffer, blob);
138
139 if (!buffer->message (font, "start table kern")) return;
140 kern.apply (&c);
141 (void) buffer->message (font, "end table kern");
142 }
143 #endif
144
145
146 /*
147 * GDEF
148 */
149
150 bool
is_blocklisted(hb_blob_t * blob,hb_face_t * face) const151 OT::GDEF::is_blocklisted (hb_blob_t *blob,
152 hb_face_t *face) const
153 {
154 #ifdef HB_NO_OT_LAYOUT_BLOCKLIST
155 return false;
156 #endif
157 /* The ugly business of blocklisting individual fonts' tables happen here!
158 * See this thread for why we finally had to bend in and do this:
159 * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
160 *
161 * In certain versions of Times New Roman Italic and Bold Italic,
162 * ASCII double quotation mark U+0022 has wrong glyph class 3 (mark)
163 * in GDEF. Many versions of Tahoma have bad GDEF tables that
164 * incorrectly classify some spacing marks such as certain IPA
165 * symbols as glyph class 3. So do older versions of Microsoft
166 * Himalaya, and the version of Cantarell shipped by Ubuntu 16.04.
167 *
168 * Nuke the GDEF tables of to avoid unwanted width-zeroing.
169 *
170 * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925
171 * https://bugzilla.mozilla.org/show_bug.cgi?id=1279693
172 * https://bugzilla.mozilla.org/show_bug.cgi?id=1279875
173 */
174 switch HB_CODEPOINT_ENCODE3(blob->length,
175 face->table.GSUB->table.get_length (),
176 face->table.GPOS->table.get_length ())
177 {
178 /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */
179 case HB_CODEPOINT_ENCODE3 (442, 2874, 42038):
180 /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */
181 case HB_CODEPOINT_ENCODE3 (430, 2874, 40662):
182 /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */
183 case HB_CODEPOINT_ENCODE3 (442, 2874, 39116):
184 /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */
185 case HB_CODEPOINT_ENCODE3 (430, 2874, 39374):
186 /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */
187 case HB_CODEPOINT_ENCODE3 (490, 3046, 41638):
188 /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */
189 case HB_CODEPOINT_ENCODE3 (478, 3046, 41902):
190 /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c tahoma.ttf from Windows 8 */
191 case HB_CODEPOINT_ENCODE3 (898, 12554, 46470):
192 /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc tahomabd.ttf from Windows 8 */
193 case HB_CODEPOINT_ENCODE3 (910, 12566, 47732):
194 /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e tahoma.ttf from Windows 8.1 */
195 case HB_CODEPOINT_ENCODE3 (928, 23298, 59332):
196 /* sha1sum:6d400781948517c3c0441ba42acb309584b73033 tahomabd.ttf from Windows 8.1 */
197 case HB_CODEPOINT_ENCODE3 (940, 23310, 60732):
198 /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
199 case HB_CODEPOINT_ENCODE3 (964, 23836, 60072):
200 /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
201 case HB_CODEPOINT_ENCODE3 (976, 23832, 61456):
202 /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846 tahoma.ttf from Windows 10 */
203 case HB_CODEPOINT_ENCODE3 (994, 24474, 60336):
204 /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343 tahomabd.ttf from Windows 10 */
205 case HB_CODEPOINT_ENCODE3 (1006, 24470, 61740):
206 /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
207 case HB_CODEPOINT_ENCODE3 (1006, 24576, 61346):
208 /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
209 case HB_CODEPOINT_ENCODE3 (1018, 24572, 62828):
210 /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5 tahoma.ttf from Windows 10 AU */
211 case HB_CODEPOINT_ENCODE3 (1006, 24576, 61352):
212 /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2 tahomabd.ttf from Windows 10 AU */
213 case HB_CODEPOINT_ENCODE3 (1018, 24572, 62834):
214 /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7 Tahoma.ttf from Mac OS X 10.9 */
215 case HB_CODEPOINT_ENCODE3 (832, 7324, 47162):
216 /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba Tahoma Bold.ttf from Mac OS X 10.9 */
217 case HB_CODEPOINT_ENCODE3 (844, 7302, 45474):
218 /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc himalaya.ttf from Windows 7 */
219 case HB_CODEPOINT_ENCODE3 (180, 13054, 7254):
220 /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0 himalaya.ttf from Windows 8 */
221 case HB_CODEPOINT_ENCODE3 (192, 12638, 7254):
222 /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427 himalaya.ttf from Windows 8.1 */
223 case HB_CODEPOINT_ENCODE3 (192, 12690, 7254):
224 /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44 cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */
225 /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371 cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */
226 case HB_CODEPOINT_ENCODE3 (188, 248, 3852):
227 /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */
228 /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */
229 case HB_CODEPOINT_ENCODE3 (188, 264, 3426):
230 /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */
231 case HB_CODEPOINT_ENCODE3 (1058, 47032, 11818):
232 /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/
233 case HB_CODEPOINT_ENCODE3 (1046, 47030, 12600):
234 /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */
235 case HB_CODEPOINT_ENCODE3 (1058, 71796, 16770):
236 /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */
237 case HB_CODEPOINT_ENCODE3 (1046, 71790, 17862):
238 /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */
239 case HB_CODEPOINT_ENCODE3 (1046, 71788, 17112):
240 /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */
241 case HB_CODEPOINT_ENCODE3 (1058, 71794, 17514):
242 /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */
243 case HB_CODEPOINT_ENCODE3 (1330, 109904, 57938):
244 /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */
245 case HB_CODEPOINT_ENCODE3 (1330, 109904, 58972):
246 /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85 Padauk.ttf
247 * "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */
248 case HB_CODEPOINT_ENCODE3 (1004, 59092, 14836):
249 return true;
250 }
251 return false;
252 }
253
254 static void
_hb_ot_layout_set_glyph_props(hb_font_t * font,hb_buffer_t * buffer)255 _hb_ot_layout_set_glyph_props (hb_font_t *font,
256 hb_buffer_t *buffer)
257 {
258 _hb_buffer_assert_gsubgpos_vars (buffer);
259
260 const auto &gdef = *font->face->table.GDEF;
261 unsigned int count = buffer->len;
262 hb_glyph_info_t *info = buffer->info;
263 for (unsigned int i = 0; i < count; i++)
264 {
265 _hb_glyph_info_set_glyph_props (&info[i], gdef.get_glyph_props (info[i].codepoint));
266 _hb_glyph_info_clear_lig_props (&info[i]);
267 }
268 }
269
270 /* Public API */
271
272 /**
273 * hb_ot_layout_has_glyph_classes:
274 * @face: #hb_face_t to work upon
275 *
276 * Tests whether a face has any glyph classes defined in its GDEF table.
277 *
278 * Return value: `true` if data found, `false` otherwise
279 *
280 **/
281 hb_bool_t
hb_ot_layout_has_glyph_classes(hb_face_t * face)282 hb_ot_layout_has_glyph_classes (hb_face_t *face)
283 {
284 return face->table.GDEF->table->has_glyph_classes ();
285 }
286
287 /**
288 * hb_ot_layout_get_glyph_class:
289 * @face: The #hb_face_t to work on
290 * @glyph: The #hb_codepoint_t code point to query
291 *
292 * Fetches the GDEF class of the requested glyph in the specified face.
293 *
294 * Return value: The #hb_ot_layout_glyph_class_t glyph class of the given code
295 * point in the GDEF table of the face.
296 *
297 * Since: 0.9.7
298 **/
299 hb_ot_layout_glyph_class_t
hb_ot_layout_get_glyph_class(hb_face_t * face,hb_codepoint_t glyph)300 hb_ot_layout_get_glyph_class (hb_face_t *face,
301 hb_codepoint_t glyph)
302 {
303 return (hb_ot_layout_glyph_class_t) face->table.GDEF->table->get_glyph_class (glyph);
304 }
305
306 /**
307 * hb_ot_layout_get_glyphs_in_class:
308 * @face: The #hb_face_t to work on
309 * @klass: The #hb_ot_layout_glyph_class_t GDEF class to retrieve
310 * @glyphs: (out): The #hb_set_t set of all glyphs belonging to the requested
311 * class.
312 *
313 * Retrieves the set of all glyphs from the face that belong to the requested
314 * glyph class in the face's GDEF table.
315 *
316 * Since: 0.9.7
317 **/
318 void
hb_ot_layout_get_glyphs_in_class(hb_face_t * face,hb_ot_layout_glyph_class_t klass,hb_set_t * glyphs)319 hb_ot_layout_get_glyphs_in_class (hb_face_t *face,
320 hb_ot_layout_glyph_class_t klass,
321 hb_set_t *glyphs /* OUT */)
322 {
323 return face->table.GDEF->table->get_glyphs_in_class (klass, glyphs);
324 }
325
326 #ifndef HB_NO_LAYOUT_UNUSED
327 /**
328 * hb_ot_layout_get_attach_points:
329 * @face: The #hb_face_t to work on
330 * @glyph: The #hb_codepoint_t code point to query
331 * @start_offset: offset of the first attachment point to retrieve
332 * @point_count: (inout) (optional): Input = the maximum number of attachment points to return;
333 * Output = the actual number of attachment points returned (may be zero)
334 * @point_array: (out) (array length=point_count): The array of attachment points found for the query
335 *
336 * Fetches a list of all attachment points for the specified glyph in the GDEF
337 * table of the face. The list returned will begin at the offset provided.
338 *
339 * Useful if the client program wishes to cache the list.
340 *
341 * Return value: Total number of attachment points for @glyph.
342 *
343 **/
344 unsigned int
hb_ot_layout_get_attach_points(hb_face_t * face,hb_codepoint_t glyph,unsigned int start_offset,unsigned int * point_count,unsigned int * point_array)345 hb_ot_layout_get_attach_points (hb_face_t *face,
346 hb_codepoint_t glyph,
347 unsigned int start_offset,
348 unsigned int *point_count /* IN/OUT */,
349 unsigned int *point_array /* OUT */)
350 {
351 return face->table.GDEF->table->get_attach_points (glyph,
352 start_offset,
353 point_count,
354 point_array);
355 }
356 /**
357 * hb_ot_layout_get_ligature_carets:
358 * @font: The #hb_font_t to work on
359 * @direction: The #hb_direction_t text direction to use
360 * @glyph: The #hb_codepoint_t code point to query
361 * @start_offset: offset of the first caret position to retrieve
362 * @caret_count: (inout) (optional): Input = the maximum number of caret positions to return;
363 * Output = the actual number of caret positions returned (may be zero)
364 * @caret_array: (out) (array length=caret_count): The array of caret positions found for the query
365 *
366 * Fetches a list of the caret positions defined for a ligature glyph in the GDEF
367 * table of the font. The list returned will begin at the offset provided.
368 *
369 * Note that a ligature that is formed from n characters will have n-1
370 * caret positions. The first character is not represented in the array,
371 * since its caret position is the glyph position.
372 *
373 * The positions returned by this function are 'unshaped', and will have to
374 * be fixed up for kerning that may be applied to the ligature glyph.
375 *
376 * Return value: Total number of ligature caret positions for @glyph.
377 *
378 **/
379 unsigned int
hb_ot_layout_get_ligature_carets(hb_font_t * font,hb_direction_t direction,hb_codepoint_t glyph,unsigned int start_offset,unsigned int * caret_count,hb_position_t * caret_array)380 hb_ot_layout_get_ligature_carets (hb_font_t *font,
381 hb_direction_t direction,
382 hb_codepoint_t glyph,
383 unsigned int start_offset,
384 unsigned int *caret_count /* IN/OUT */,
385 hb_position_t *caret_array /* OUT */)
386 {
387 return font->face->table.GDEF->table->get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
388 }
389 #endif
390
391
392 /*
393 * GSUB/GPOS
394 */
395
396 bool
is_blocklisted(hb_blob_t * blob HB_UNUSED,hb_face_t * face) const397 GSUB::is_blocklisted (hb_blob_t *blob HB_UNUSED,
398 hb_face_t *face) const
399 {
400 #ifdef HB_NO_OT_LAYOUT_BLOCKLIST
401 return false;
402 #endif
403 return false;
404 }
405
406 bool
is_blocklisted(hb_blob_t * blob HB_UNUSED,hb_face_t * face HB_UNUSED) const407 GPOS::is_blocklisted (hb_blob_t *blob HB_UNUSED,
408 hb_face_t *face HB_UNUSED) const
409 {
410 #ifdef HB_NO_OT_LAYOUT_BLOCKLIST
411 return false;
412 #endif
413 return false;
414 }
415
416 static const OT::GSUBGPOS&
get_gsubgpos_table(hb_face_t * face,hb_tag_t table_tag)417 get_gsubgpos_table (hb_face_t *face,
418 hb_tag_t table_tag)
419 {
420 switch (table_tag) {
421 case HB_OT_TAG_GSUB: return *face->table.GSUB->table;
422 case HB_OT_TAG_GPOS: return *face->table.GPOS->table;
423 default: return Null (OT::GSUBGPOS);
424 }
425 }
426
427
428 /**
429 * hb_ot_layout_table_get_script_tags:
430 * @face: #hb_face_t to work upon
431 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
432 * @start_offset: offset of the first script tag to retrieve
433 * @script_count: (inout) (optional): Input = the maximum number of script tags to return;
434 * Output = the actual number of script tags returned (may be zero)
435 * @script_tags: (out) (array length=script_count): The array of #hb_tag_t script tags found for the query
436 *
437 * Fetches a list of all scripts enumerated in the specified face's GSUB table
438 * or GPOS table. The list returned will begin at the offset provided.
439 *
440 * Return value: Total number of script tags.
441 *
442 **/
443 unsigned int
hb_ot_layout_table_get_script_tags(hb_face_t * face,hb_tag_t table_tag,unsigned int start_offset,unsigned int * script_count,hb_tag_t * script_tags)444 hb_ot_layout_table_get_script_tags (hb_face_t *face,
445 hb_tag_t table_tag,
446 unsigned int start_offset,
447 unsigned int *script_count /* IN/OUT */,
448 hb_tag_t *script_tags /* OUT */)
449 {
450 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
451
452 return g.get_script_tags (start_offset, script_count, script_tags);
453 }
454
455 #define HB_OT_TAG_LATIN_SCRIPT HB_TAG ('l', 'a', 't', 'n')
456
457 /**
458 * hb_ot_layout_table_find_script:
459 * @face: #hb_face_t to work upon
460 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
461 * @script_tag: #hb_tag_t of the script tag requested
462 * @script_index: (out): The index of the requested script tag
463 *
464 * Fetches the index if a given script tag in the specified face's GSUB table
465 * or GPOS table.
466 *
467 * Return value: `true` if the script is found, `false` otherwise
468 *
469 **/
470 hb_bool_t
hb_ot_layout_table_find_script(hb_face_t * face,hb_tag_t table_tag,hb_tag_t script_tag,unsigned int * script_index)471 hb_ot_layout_table_find_script (hb_face_t *face,
472 hb_tag_t table_tag,
473 hb_tag_t script_tag,
474 unsigned int *script_index /* OUT */)
475 {
476 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
477 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
478
479 if (g.find_script_index (script_tag, script_index))
480 return true;
481
482 /* try finding 'DFLT' */
483 if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
484 return false;
485
486 /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
487 * including many versions of DejaVu Sans Mono! */
488 if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
489 return false;
490
491 /* try with 'latn'; some old fonts put their features there even though
492 they're really trying to support Thai, for example :( */
493 if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index))
494 return false;
495
496 if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
497 return false;
498 }
499
500 #ifndef HB_DISABLE_DEPRECATED
501 /**
502 * hb_ot_layout_table_choose_script:
503 * @face: #hb_face_t to work upon
504 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
505 * @script_tags: Array of #hb_tag_t script tags
506 * @script_index: (out): The index of the chosen script
507 * @chosen_script: (out): #hb_tag_t of the chosen script
508 *
509 * Deprecated since 2.0.0
510 **/
511 hb_bool_t
hb_ot_layout_table_choose_script(hb_face_t * face,hb_tag_t table_tag,const hb_tag_t * script_tags,unsigned int * script_index,hb_tag_t * chosen_script)512 hb_ot_layout_table_choose_script (hb_face_t *face,
513 hb_tag_t table_tag,
514 const hb_tag_t *script_tags,
515 unsigned int *script_index /* OUT */,
516 hb_tag_t *chosen_script /* OUT */)
517 {
518 const hb_tag_t *t;
519 for (t = script_tags; *t; t++);
520 return hb_ot_layout_table_select_script (face, table_tag, t - script_tags, script_tags, script_index, chosen_script);
521 }
522 #endif
523
524 /**
525 * hb_ot_layout_table_select_script:
526 * @face: #hb_face_t to work upon
527 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
528 * @script_count: Number of script tags in the array
529 * @script_tags: Array of #hb_tag_t script tags
530 * @script_index: (out) (optional): The index of the requested script
531 * @chosen_script: (out) (optional): #hb_tag_t of the requested script
532 *
533 * Selects an OpenType script for @table_tag from the @script_tags array.
534 *
535 * If the table does not have any of the requested scripts, then `DFLT`,
536 * `dflt`, and `latn` tags are tried in that order. If the table still does not
537 * have any of these scripts, @script_index is set to
538 * #HB_OT_LAYOUT_NO_SCRIPT_INDEX and @chosen_script is set to #HB_TAG_NONE.
539 *
540 * Return value:
541 * `true` if one of the requested scripts is selected, `false` if a fallback
542 * script is selected or if no scripts are selected.
543 *
544 * Since: 2.0.0
545 **/
546 hb_bool_t
hb_ot_layout_table_select_script(hb_face_t * face,hb_tag_t table_tag,unsigned int script_count,const hb_tag_t * script_tags,unsigned int * script_index,hb_tag_t * chosen_script)547 hb_ot_layout_table_select_script (hb_face_t *face,
548 hb_tag_t table_tag,
549 unsigned int script_count,
550 const hb_tag_t *script_tags,
551 unsigned int *script_index /* OUT */,
552 hb_tag_t *chosen_script /* OUT */)
553 {
554 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
555 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
556 unsigned int i;
557
558 for (i = 0; i < script_count; i++)
559 {
560 if (g.find_script_index (script_tags[i], script_index))
561 {
562 if (chosen_script)
563 *chosen_script = script_tags[i];
564 return true;
565 }
566 }
567
568 /* try finding 'DFLT' */
569 if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
570 if (chosen_script)
571 *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
572 return false;
573 }
574
575 /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
576 if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
577 if (chosen_script)
578 *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
579 return false;
580 }
581
582 /* try with 'latn'; some old fonts put their features there even though
583 they're really trying to support Thai, for example :( */
584 if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
585 if (chosen_script)
586 *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
587 return false;
588 }
589
590 if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
591 if (chosen_script)
592 *chosen_script = HB_TAG_NONE;
593 return false;
594 }
595
596
597 /**
598 * hb_ot_layout_table_get_feature_tags:
599 * @face: #hb_face_t to work upon
600 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
601 * @start_offset: offset of the first feature tag to retrieve
602 * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return;
603 * Output = the actual number of feature tags returned (may be zero)
604 * @feature_tags: (out) (array length=feature_count): Array of feature tags found in the table
605 *
606 * Fetches a list of all feature tags in the given face's GSUB or GPOS table.
607 * Note that there might be duplicate feature tags, belonging to different
608 * script/language-system pairs of the table.
609 *
610 * Return value: Total number of feature tags.
611 *
612 * Since: 0.6.0
613 *
614 **/
615 unsigned int
hb_ot_layout_table_get_feature_tags(hb_face_t * face,hb_tag_t table_tag,unsigned int start_offset,unsigned int * feature_count,hb_tag_t * feature_tags)616 hb_ot_layout_table_get_feature_tags (hb_face_t *face,
617 hb_tag_t table_tag,
618 unsigned int start_offset,
619 unsigned int *feature_count /* IN/OUT */,
620 hb_tag_t *feature_tags /* OUT */)
621 {
622 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
623
624 return g.get_feature_tags (start_offset, feature_count, feature_tags);
625 }
626
627
628 /**
629 * hb_ot_layout_table_find_feature:
630 * @face: #hb_face_t to work upon
631 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
632 * @feature_tag: The #hb_tag_t of the requested feature tag
633 * @feature_index: (out): The index of the requested feature
634 *
635 * Fetches the index for a given feature tag in the specified face's GSUB table
636 * or GPOS table.
637 *
638 * Return value: `true` if the feature is found, `false` otherwise
639 *
640 * Since: 0.6.0
641 *
642 **/
643 bool
hb_ot_layout_table_find_feature(hb_face_t * face,hb_tag_t table_tag,hb_tag_t feature_tag,unsigned int * feature_index)644 hb_ot_layout_table_find_feature (hb_face_t *face,
645 hb_tag_t table_tag,
646 hb_tag_t feature_tag,
647 unsigned int *feature_index /* OUT */)
648 {
649 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
650 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
651
652 unsigned int num_features = g.get_feature_count ();
653 for (unsigned int i = 0; i < num_features; i++)
654 {
655 if (feature_tag == g.get_feature_tag (i)) {
656 if (feature_index) *feature_index = i;
657 return true;
658 }
659 }
660
661 if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
662 return false;
663 }
664
665
666 /**
667 * hb_ot_layout_script_get_language_tags:
668 * @face: #hb_face_t to work upon
669 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
670 * @script_index: The index of the requested script tag
671 * @start_offset: offset of the first language tag to retrieve
672 * @language_count: (inout) (optional): Input = the maximum number of language tags to return;
673 * Output = the actual number of language tags returned (may be zero)
674 * @language_tags: (out) (array length=language_count): Array of language tags found in the table
675 *
676 * Fetches a list of language tags in the given face's GSUB or GPOS table, underneath
677 * the specified script index. The list returned will begin at the offset provided.
678 *
679 * Return value: Total number of language tags.
680 *
681 * Since: 0.6.0
682 *
683 **/
684 unsigned int
hb_ot_layout_script_get_language_tags(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int start_offset,unsigned int * language_count,hb_tag_t * language_tags)685 hb_ot_layout_script_get_language_tags (hb_face_t *face,
686 hb_tag_t table_tag,
687 unsigned int script_index,
688 unsigned int start_offset,
689 unsigned int *language_count /* IN/OUT */,
690 hb_tag_t *language_tags /* OUT */)
691 {
692 const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
693
694 return s.get_lang_sys_tags (start_offset, language_count, language_tags);
695 }
696
697
698 #ifndef HB_DISABLE_DEPRECATED
699 /**
700 * hb_ot_layout_script_find_language:
701 * @face: #hb_face_t to work upon
702 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
703 * @script_index: The index of the requested script tag
704 * @language_tag: The #hb_tag_t of the requested language
705 * @language_index: The index of the requested language
706 *
707 * Fetches the index of a given language tag in the specified face's GSUB table
708 * or GPOS table, underneath the specified script tag.
709 *
710 * Return value: `true` if the language tag is found, `false` otherwise
711 *
712 * Since: 0.6.0
713 * Deprecated: 2.0.0
714 **/
715 hb_bool_t
hb_ot_layout_script_find_language(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,hb_tag_t language_tag,unsigned int * language_index)716 hb_ot_layout_script_find_language (hb_face_t *face,
717 hb_tag_t table_tag,
718 unsigned int script_index,
719 hb_tag_t language_tag,
720 unsigned int *language_index)
721 {
722 return hb_ot_layout_script_select_language (face,
723 table_tag,
724 script_index,
725 1,
726 &language_tag,
727 language_index);
728 }
729 #endif
730
731
732 /**
733 * hb_ot_layout_script_select_language2:
734 * @face: #hb_face_t to work upon
735 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
736 * @script_index: The index of the requested script tag
737 * @language_count: The number of languages in the specified script
738 * @language_tags: The array of language tags
739 * @language_index: (out): The index of the chosen language
740 * @chosen_language: (out): #hb_tag_t of the chosen language
741 *
742 * Fetches the index of the first language tag fom @language_tags that is present
743 * in the specified face's GSUB or GPOS table, underneath the specified script
744 * index.
745 *
746 * If none of the given language tags is found, `false` is returned and
747 * @language_index is set to #HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX and
748 * @chosen_language is set to #HB_TAG_NONE.
749 *
750 * Return value: `true` if one of the given language tags is found, `false` otherwise
751 *
752 * Since: 7.0.0
753 **/
754 hb_bool_t
hb_ot_layout_script_select_language2(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_count,const hb_tag_t * language_tags,unsigned int * language_index,hb_tag_t * chosen_language)755 hb_ot_layout_script_select_language2 (hb_face_t *face,
756 hb_tag_t table_tag,
757 unsigned int script_index,
758 unsigned int language_count,
759 const hb_tag_t *language_tags,
760 unsigned int *language_index /* OUT */,
761 hb_tag_t *chosen_language /* OUT */)
762 {
763 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX), "");
764 const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
765 unsigned int i;
766
767 for (i = 0; i < language_count; i++)
768 {
769 if (s.find_lang_sys_index (language_tags[i], language_index))
770 {
771 if (chosen_language)
772 *chosen_language = language_tags[i];
773 return true;
774 }
775 }
776
777 /* try finding 'dflt' */
778 if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
779 {
780 if (chosen_language)
781 *chosen_language = HB_OT_TAG_DEFAULT_LANGUAGE;
782 return false;
783 }
784
785 if (language_index)
786 *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
787 if (chosen_language)
788 *chosen_language = HB_TAG_NONE;
789 return false;
790 }
791
792 /**
793 * hb_ot_layout_script_select_language:
794 * @face: #hb_face_t to work upon
795 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
796 * @script_index: The index of the requested script tag
797 * @language_count: The number of languages in the specified script
798 * @language_tags: The array of language tags
799 * @language_index: (out): The index of the requested language
800 *
801 * Fetches the index of the first language tag fom @language_tags that is present
802 * in the specified face's GSUB or GPOS table, underneath the specified script
803 * index.
804 *
805 * If none of the given language tags is found, `false` is returned and
806 * @language_index is set to the default language index.
807 *
808 * Return value: `true` if one of the given language tags is found, `false` otherwise
809 *
810 * Since: 2.0.0
811 **/
812 hb_bool_t
hb_ot_layout_script_select_language(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_count,const hb_tag_t * language_tags,unsigned int * language_index)813 hb_ot_layout_script_select_language (hb_face_t *face,
814 hb_tag_t table_tag,
815 unsigned int script_index,
816 unsigned int language_count,
817 const hb_tag_t *language_tags,
818 unsigned int *language_index /* OUT */)
819 {
820 return hb_ot_layout_script_select_language2 (face, table_tag,
821 script_index,
822 language_count, language_tags,
823 language_index, nullptr);
824 }
825
826 /**
827 * hb_ot_layout_language_get_required_feature_index:
828 * @face: #hb_face_t to work upon
829 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
830 * @script_index: The index of the requested script tag
831 * @language_index: The index of the requested language tag
832 * @feature_index: (out): The index of the requested feature
833 *
834 * Fetches the index of a requested feature in the given face's GSUB or GPOS table,
835 * underneath the specified script and language.
836 *
837 * Return value: `true` if the feature is found, `false` otherwise
838 *
839 * Since: 0.6.0
840 *
841 **/
842 hb_bool_t
hb_ot_layout_language_get_required_feature_index(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_index,unsigned int * feature_index)843 hb_ot_layout_language_get_required_feature_index (hb_face_t *face,
844 hb_tag_t table_tag,
845 unsigned int script_index,
846 unsigned int language_index,
847 unsigned int *feature_index /* OUT */)
848 {
849 return hb_ot_layout_language_get_required_feature (face,
850 table_tag,
851 script_index,
852 language_index,
853 feature_index,
854 nullptr);
855 }
856
857
858 /**
859 * hb_ot_layout_language_get_required_feature:
860 * @face: #hb_face_t to work upon
861 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
862 * @script_index: The index of the requested script tag
863 * @language_index: The index of the requested language tag
864 * @feature_index: (out): The index of the requested feature
865 * @feature_tag: (out): The #hb_tag_t of the requested feature
866 *
867 * Fetches the tag of a requested feature index in the given face's GSUB or GPOS table,
868 * underneath the specified script and language.
869 *
870 * Return value: `true` if the feature is found, `false` otherwise
871 *
872 * Since: 0.9.30
873 **/
874 hb_bool_t
hb_ot_layout_language_get_required_feature(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_index,unsigned int * feature_index,hb_tag_t * feature_tag)875 hb_ot_layout_language_get_required_feature (hb_face_t *face,
876 hb_tag_t table_tag,
877 unsigned int script_index,
878 unsigned int language_index,
879 unsigned int *feature_index /* OUT */,
880 hb_tag_t *feature_tag /* OUT */)
881 {
882 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
883 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
884
885 unsigned int index = l.get_required_feature_index ();
886 if (feature_index) *feature_index = index;
887 if (feature_tag) *feature_tag = g.get_feature_tag (index);
888
889 return l.has_required_feature ();
890 }
891
892
893 /**
894 * hb_ot_layout_language_get_feature_indexes:
895 * @face: #hb_face_t to work upon
896 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
897 * @script_index: The index of the requested script tag
898 * @language_index: The index of the requested language tag
899 * @start_offset: offset of the first feature tag to retrieve
900 * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return;
901 * Output: the actual number of feature tags returned (may be zero)
902 * @feature_indexes: (out) (array length=feature_count): The array of feature indexes found for the query
903 *
904 * Fetches a list of all features in the specified face's GSUB table
905 * or GPOS table, underneath the specified script and language. The list
906 * returned will begin at the offset provided.
907 *
908 * Return value: Total number of features.
909 *
910 * Since: 0.6.0
911 *
912 **/
913 unsigned int
hb_ot_layout_language_get_feature_indexes(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_index,unsigned int start_offset,unsigned int * feature_count,unsigned int * feature_indexes)914 hb_ot_layout_language_get_feature_indexes (hb_face_t *face,
915 hb_tag_t table_tag,
916 unsigned int script_index,
917 unsigned int language_index,
918 unsigned int start_offset,
919 unsigned int *feature_count /* IN/OUT */,
920 unsigned int *feature_indexes /* OUT */)
921 {
922 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
923 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
924
925 return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
926 }
927
928
929 /**
930 * hb_ot_layout_language_get_feature_tags:
931 * @face: #hb_face_t to work upon
932 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
933 * @script_index: The index of the requested script tag
934 * @language_index: The index of the requested language tag
935 * @start_offset: offset of the first feature tag to retrieve
936 * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return;
937 * Output = the actual number of feature tags returned (may be zero)
938 * @feature_tags: (out) (array length=feature_count): The array of #hb_tag_t feature tags found for the query
939 *
940 * Fetches a list of all features in the specified face's GSUB table
941 * or GPOS table, underneath the specified script and language. The list
942 * returned will begin at the offset provided.
943 *
944 * Return value: Total number of feature tags.
945 *
946 * Since: 0.6.0
947 *
948 **/
949 unsigned int
hb_ot_layout_language_get_feature_tags(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_index,unsigned int start_offset,unsigned int * feature_count,hb_tag_t * feature_tags)950 hb_ot_layout_language_get_feature_tags (hb_face_t *face,
951 hb_tag_t table_tag,
952 unsigned int script_index,
953 unsigned int language_index,
954 unsigned int start_offset,
955 unsigned int *feature_count /* IN/OUT */,
956 hb_tag_t *feature_tags /* OUT */)
957 {
958 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
959 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
960
961 static_assert ((sizeof (unsigned int) == sizeof (hb_tag_t)), "");
962 unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
963
964 if (feature_tags) {
965 unsigned int count = *feature_count;
966 for (unsigned int i = 0; i < count; i++)
967 feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
968 }
969
970 return ret;
971 }
972
973
974 /**
975 * hb_ot_layout_language_find_feature:
976 * @face: #hb_face_t to work upon
977 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
978 * @script_index: The index of the requested script tag
979 * @language_index: The index of the requested language tag
980 * @feature_tag: #hb_tag_t of the feature tag requested
981 * @feature_index: (out): The index of the requested feature
982 *
983 * Fetches the index of a given feature tag in the specified face's GSUB table
984 * or GPOS table, underneath the specified script and language.
985 *
986 * Return value: `true` if the feature is found, `false` otherwise
987 *
988 * Since: 0.6.0
989 *
990 **/
991 hb_bool_t
hb_ot_layout_language_find_feature(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_index,hb_tag_t feature_tag,unsigned int * feature_index)992 hb_ot_layout_language_find_feature (hb_face_t *face,
993 hb_tag_t table_tag,
994 unsigned int script_index,
995 unsigned int language_index,
996 hb_tag_t feature_tag,
997 unsigned int *feature_index /* OUT */)
998 {
999 static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
1000 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1001 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
1002
1003 unsigned int num_features = l.get_feature_count ();
1004 for (unsigned int i = 0; i < num_features; i++) {
1005 unsigned int f_index = l.get_feature_index (i);
1006
1007 if (feature_tag == g.get_feature_tag (f_index)) {
1008 if (feature_index) *feature_index = f_index;
1009 return true;
1010 }
1011 }
1012
1013 if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
1014 return false;
1015 }
1016
1017
1018 /**
1019 * hb_ot_layout_feature_get_lookups:
1020 * @face: #hb_face_t to work upon
1021 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1022 * @feature_index: The index of the requested feature
1023 * @start_offset: offset of the first lookup to retrieve
1024 * @lookup_count: (inout) (optional): Input = the maximum number of lookups to return;
1025 * Output = the actual number of lookups returned (may be zero)
1026 * @lookup_indexes: (out) (array length=lookup_count): The array of lookup indexes found for the query
1027 *
1028 * Fetches a list of all lookups enumerated for the specified feature, in
1029 * the specified face's GSUB table or GPOS table. The list returned will
1030 * begin at the offset provided.
1031 *
1032 * Return value: Total number of lookups.
1033 *
1034 * Since: 0.9.7
1035 **/
1036 unsigned int
hb_ot_layout_feature_get_lookups(hb_face_t * face,hb_tag_t table_tag,unsigned int feature_index,unsigned int start_offset,unsigned int * lookup_count,unsigned int * lookup_indexes)1037 hb_ot_layout_feature_get_lookups (hb_face_t *face,
1038 hb_tag_t table_tag,
1039 unsigned int feature_index,
1040 unsigned int start_offset,
1041 unsigned int *lookup_count /* IN/OUT */,
1042 unsigned int *lookup_indexes /* OUT */)
1043 {
1044 return hb_ot_layout_feature_with_variations_get_lookups (face,
1045 table_tag,
1046 feature_index,
1047 HB_OT_LAYOUT_NO_VARIATIONS_INDEX,
1048 start_offset,
1049 lookup_count,
1050 lookup_indexes);
1051 }
1052
1053
1054 /**
1055 * hb_ot_layout_table_get_lookup_count:
1056 * @face: #hb_face_t to work upon
1057 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1058 *
1059 * Fetches the total number of lookups enumerated in the specified
1060 * face's GSUB table or GPOS table.
1061 *
1062 * Return value: Total number of lookups.
1063 *
1064 * Since: 0.9.22
1065 **/
1066 unsigned int
hb_ot_layout_table_get_lookup_count(hb_face_t * face,hb_tag_t table_tag)1067 hb_ot_layout_table_get_lookup_count (hb_face_t *face,
1068 hb_tag_t table_tag)
1069 {
1070 return get_gsubgpos_table (face, table_tag).get_lookup_count ();
1071 }
1072
1073
1074 struct hb_collect_features_context_t
1075 {
hb_collect_features_context_thb_collect_features_context_t1076 hb_collect_features_context_t (hb_face_t *face,
1077 hb_tag_t table_tag,
1078 hb_set_t *feature_indices_,
1079 const hb_tag_t *features)
1080
1081 : g (get_gsubgpos_table (face, table_tag)),
1082 feature_indices (feature_indices_),
1083 has_feature_filter (false),
1084 script_count (0),langsys_count (0), feature_index_count (0)
1085 {
1086 compute_feature_filter (features);
1087 }
1088
compute_feature_filterhb_collect_features_context_t1089 void compute_feature_filter (const hb_tag_t *features)
1090 {
1091 if (features == nullptr)
1092 {
1093 has_feature_filter = false;
1094 return;
1095 }
1096
1097 has_feature_filter = true;
1098 hb_set_t features_set;
1099 for (; *features; features++)
1100 features_set.add (*features);
1101
1102 for (unsigned i = 0; i < g.get_feature_count (); i++)
1103 {
1104 hb_tag_t tag = g.get_feature_tag (i);
1105 if (features_set.has (tag))
1106 feature_indices_filter.add(i);
1107 }
1108 }
1109
visitedhb_collect_features_context_t1110 bool visited (const OT::Script &s)
1111 {
1112 /* We might have Null() object here. Don't want to involve
1113 * that in the memoize. So, detect empty objects and return. */
1114 if (unlikely (!s.has_default_lang_sys () &&
1115 !s.get_lang_sys_count ()))
1116 return true;
1117
1118 if (script_count++ > HB_MAX_SCRIPTS)
1119 return true;
1120
1121 return visited (s, visited_script);
1122 }
visitedhb_collect_features_context_t1123 bool visited (const OT::LangSys &l)
1124 {
1125 /* We might have Null() object here. Don't want to involve
1126 * that in the memoize. So, detect empty objects and return. */
1127 if (unlikely (!l.has_required_feature () &&
1128 !l.get_feature_count ()))
1129 return true;
1130
1131 if (langsys_count++ > HB_MAX_LANGSYS)
1132 return true;
1133
1134 return visited (l, visited_langsys);
1135 }
1136
visited_feature_indiceshb_collect_features_context_t1137 bool visited_feature_indices (unsigned count)
1138 {
1139 feature_index_count += count;
1140 return feature_index_count > HB_MAX_FEATURE_INDICES;
1141 }
1142
1143 private:
1144 template <typename T>
visitedhb_collect_features_context_t1145 bool visited (const T &p, hb_set_t &visited_set)
1146 {
1147 hb_codepoint_t delta = (hb_codepoint_t) ((uintptr_t) &p - (uintptr_t) &g);
1148 if (visited_set.has (delta))
1149 return true;
1150
1151 visited_set.add (delta);
1152 return false;
1153 }
1154
1155 public:
1156 const OT::GSUBGPOS &g;
1157 hb_set_t *feature_indices;
1158 hb_set_t feature_indices_filter;
1159 bool has_feature_filter;
1160
1161 private:
1162 hb_set_t visited_script;
1163 hb_set_t visited_langsys;
1164 unsigned int script_count;
1165 unsigned int langsys_count;
1166 unsigned int feature_index_count;
1167 };
1168
1169 static void
langsys_collect_features(hb_collect_features_context_t * c,const OT::LangSys & l)1170 langsys_collect_features (hb_collect_features_context_t *c,
1171 const OT::LangSys &l)
1172 {
1173 if (c->visited (l)) return;
1174
1175 if (!c->has_feature_filter)
1176 {
1177 /* All features. */
1178 if (l.has_required_feature () && !c->visited_feature_indices (1))
1179 c->feature_indices->add (l.get_required_feature_index ());
1180
1181 // TODO(garretrieger): filter out indices >= feature count?
1182 if (!c->visited_feature_indices (l.featureIndex.len))
1183 l.add_feature_indexes_to (c->feature_indices);
1184 }
1185 else
1186 {
1187 if (c->feature_indices_filter.is_empty()) return;
1188 unsigned int num_features = l.get_feature_count ();
1189 for (unsigned int i = 0; i < num_features; i++)
1190 {
1191 unsigned int feature_index = l.get_feature_index (i);
1192 if (!c->feature_indices_filter.has (feature_index)) continue;
1193
1194 c->feature_indices->add (feature_index);
1195 c->feature_indices_filter.del (feature_index);
1196 }
1197 }
1198 }
1199
1200 static void
script_collect_features(hb_collect_features_context_t * c,const OT::Script & s,const hb_tag_t * languages)1201 script_collect_features (hb_collect_features_context_t *c,
1202 const OT::Script &s,
1203 const hb_tag_t *languages)
1204 {
1205 if (c->visited (s)) return;
1206
1207 if (!languages)
1208 {
1209 /* All languages. */
1210 if (s.has_default_lang_sys ())
1211 langsys_collect_features (c,
1212 s.get_default_lang_sys ());
1213
1214
1215 unsigned int count = s.get_lang_sys_count ();
1216 for (unsigned int language_index = 0; language_index < count; language_index++)
1217 langsys_collect_features (c,
1218 s.get_lang_sys (language_index));
1219 }
1220 else
1221 {
1222 for (; *languages; languages++)
1223 {
1224 unsigned int language_index;
1225 if (s.find_lang_sys_index (*languages, &language_index))
1226 langsys_collect_features (c,
1227 s.get_lang_sys (language_index));
1228
1229 }
1230 }
1231 }
1232
1233
1234 /**
1235 * hb_ot_layout_collect_features:
1236 * @face: #hb_face_t to work upon
1237 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1238 * @scripts: (nullable) (array zero-terminated=1): The array of scripts to collect features for,
1239 * terminated by %HB_TAG_NONE
1240 * @languages: (nullable) (array zero-terminated=1): The array of languages to collect features for,
1241 * terminated by %HB_TAG_NONE
1242 * @features: (nullable) (array zero-terminated=1): The array of features to collect,
1243 * terminated by %HB_TAG_NONE
1244 * @feature_indexes: (out): The set of feature indexes found for the query
1245 *
1246 * Fetches a list of all feature indexes in the specified face's GSUB table
1247 * or GPOS table, underneath the specified scripts, languages, and features.
1248 * If no list of scripts is provided, all scripts will be queried. If no list
1249 * of languages is provided, all languages will be queried. If no list of
1250 * features is provided, all features will be queried.
1251 *
1252 * Since: 1.8.5
1253 **/
1254 void
hb_ot_layout_collect_features(hb_face_t * face,hb_tag_t table_tag,const hb_tag_t * scripts,const hb_tag_t * languages,const hb_tag_t * features,hb_set_t * feature_indexes)1255 hb_ot_layout_collect_features (hb_face_t *face,
1256 hb_tag_t table_tag,
1257 const hb_tag_t *scripts,
1258 const hb_tag_t *languages,
1259 const hb_tag_t *features,
1260 hb_set_t *feature_indexes /* OUT */)
1261 {
1262 hb_collect_features_context_t c (face, table_tag, feature_indexes, features);
1263 if (!scripts)
1264 {
1265 /* All scripts. */
1266 unsigned int count = c.g.get_script_count ();
1267 for (unsigned int script_index = 0; script_index < count; script_index++)
1268 script_collect_features (&c,
1269 c.g.get_script (script_index),
1270 languages);
1271 }
1272 else
1273 {
1274 for (; *scripts; scripts++)
1275 {
1276 unsigned int script_index;
1277 if (c.g.find_script_index (*scripts, &script_index))
1278 script_collect_features (&c,
1279 c.g.get_script (script_index),
1280 languages);
1281 }
1282 }
1283 }
1284
1285 /**
1286 * hb_ot_layout_collect_features_map:
1287 * @face: #hb_face_t to work upon
1288 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1289 * @script_index: The index of the requested script tag
1290 * @language_index: The index of the requested language tag
1291 * @feature_map: (out): The map of feature tag to feature index.
1292 *
1293 * Fetches the mapping from feature tags to feature indexes for
1294 * the specified script and language.
1295 *
1296 * Since: 8.1.0
1297 **/
1298 void
hb_ot_layout_collect_features_map(hb_face_t * face,hb_tag_t table_tag,unsigned script_index,unsigned language_index,hb_map_t * feature_map)1299 hb_ot_layout_collect_features_map (hb_face_t *face,
1300 hb_tag_t table_tag,
1301 unsigned script_index,
1302 unsigned language_index,
1303 hb_map_t *feature_map /* OUT */)
1304 {
1305 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1306 const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
1307
1308 unsigned int count = l.get_feature_indexes (0, nullptr, nullptr);
1309 feature_map->alloc (count);
1310
1311 /* Loop in reverse, such that earlier entries win. That emulates
1312 * a linear search, which seems to be what other implementations do.
1313 * We found that with arialuni_t.ttf, the "ur" language system has
1314 * duplicate features, and the earlier ones work but not later ones.
1315 */
1316 for (unsigned int i = count; i; i--)
1317 {
1318 unsigned feature_index = 0;
1319 unsigned feature_count = 1;
1320 l.get_feature_indexes (i - 1, &feature_count, &feature_index);
1321 if (!feature_count)
1322 break;
1323 hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1324 feature_map->set (feature_tag, feature_index);
1325 }
1326 }
1327
1328
1329 /**
1330 * hb_ot_layout_collect_lookups:
1331 * @face: #hb_face_t to work upon
1332 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1333 * @scripts: (nullable) (array zero-terminated=1): The array of scripts to collect lookups for,
1334 * terminated by %HB_TAG_NONE
1335 * @languages: (nullable) (array zero-terminated=1): The array of languages to collect lookups for,
1336 * terminated by %HB_TAG_NONE
1337 * @features: (nullable) (array zero-terminated=1): The array of features to collect lookups for,
1338 * terminated by %HB_TAG_NONE
1339 * @lookup_indexes: (out): The array of lookup indexes found for the query
1340 *
1341 * Fetches a list of all feature-lookup indexes in the specified face's GSUB
1342 * table or GPOS table, underneath the specified scripts, languages, and
1343 * features. If no list of scripts is provided, all scripts will be queried.
1344 * If no list of languages is provided, all languages will be queried. If no
1345 * list of features is provided, all features will be queried.
1346 *
1347 * Since: 0.9.8
1348 **/
1349 void
hb_ot_layout_collect_lookups(hb_face_t * face,hb_tag_t table_tag,const hb_tag_t * scripts,const hb_tag_t * languages,const hb_tag_t * features,hb_set_t * lookup_indexes)1350 hb_ot_layout_collect_lookups (hb_face_t *face,
1351 hb_tag_t table_tag,
1352 const hb_tag_t *scripts,
1353 const hb_tag_t *languages,
1354 const hb_tag_t *features,
1355 hb_set_t *lookup_indexes /* OUT */)
1356 {
1357 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1358
1359 hb_set_t feature_indexes;
1360 hb_ot_layout_collect_features (face, table_tag, scripts, languages, features, &feature_indexes);
1361
1362 for (auto feature_index : feature_indexes)
1363 g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes);
1364
1365 g.feature_variation_collect_lookups (&feature_indexes, nullptr, lookup_indexes);
1366 }
1367
1368
1369 #ifndef HB_NO_LAYOUT_COLLECT_GLYPHS
1370 /**
1371 * hb_ot_layout_lookup_collect_glyphs:
1372 * @face: #hb_face_t to work upon
1373 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1374 * @lookup_index: The index of the feature lookup to query
1375 * @glyphs_before: (out): Array of glyphs preceding the substitution range
1376 * @glyphs_input: (out): Array of input glyphs that would be substituted by the lookup
1377 * @glyphs_after: (out): Array of glyphs following the substitution range
1378 * @glyphs_output: (out): Array of glyphs that would be the substituted output of the lookup
1379 *
1380 * Fetches a list of all glyphs affected by the specified lookup in the
1381 * specified face's GSUB table or GPOS table.
1382 *
1383 * Since: 0.9.7
1384 **/
1385 void
hb_ot_layout_lookup_collect_glyphs(hb_face_t * face,hb_tag_t table_tag,unsigned int lookup_index,hb_set_t * glyphs_before,hb_set_t * glyphs_input,hb_set_t * glyphs_after,hb_set_t * glyphs_output)1386 hb_ot_layout_lookup_collect_glyphs (hb_face_t *face,
1387 hb_tag_t table_tag,
1388 unsigned int lookup_index,
1389 hb_set_t *glyphs_before, /* OUT. May be NULL */
1390 hb_set_t *glyphs_input, /* OUT. May be NULL */
1391 hb_set_t *glyphs_after, /* OUT. May be NULL */
1392 hb_set_t *glyphs_output /* OUT. May be NULL */)
1393 {
1394 OT::hb_collect_glyphs_context_t c (face,
1395 glyphs_before,
1396 glyphs_input,
1397 glyphs_after,
1398 glyphs_output);
1399
1400 switch (table_tag)
1401 {
1402 case HB_OT_TAG_GSUB:
1403 {
1404 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
1405 l.collect_glyphs (&c);
1406 return;
1407 }
1408 case HB_OT_TAG_GPOS:
1409 {
1410 const OT::PosLookup& l = face->table.GPOS->table->get_lookup (lookup_index);
1411 l.collect_glyphs (&c);
1412 return;
1413 }
1414 }
1415 }
1416 #endif
1417
1418
1419 /* Variations support */
1420
1421
1422 /**
1423 * hb_ot_layout_table_find_feature_variations:
1424 * @face: #hb_face_t to work upon
1425 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1426 * @coords: The variation coordinates to query
1427 * @num_coords: The number of variation coordinates
1428 * @variations_index: (out): The array of feature variations found for the query
1429 *
1430 * Fetches a list of feature variations in the specified face's GSUB table
1431 * or GPOS table, at the specified variation coordinates.
1432 *
1433 * Return value: `true` if feature variations were found, `false` otherwise.
1434 *
1435 * Since: 1.4.0
1436 *
1437 **/
1438 hb_bool_t
hb_ot_layout_table_find_feature_variations(hb_face_t * face,hb_tag_t table_tag,const int * coords,unsigned int num_coords,unsigned int * variations_index)1439 hb_ot_layout_table_find_feature_variations (hb_face_t *face,
1440 hb_tag_t table_tag,
1441 const int *coords,
1442 unsigned int num_coords,
1443 unsigned int *variations_index /* out */)
1444 {
1445 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1446 const OT::GDEF &gdef = *face->table.GDEF->table;
1447
1448 auto instancer = OT::ItemVarStoreInstancer(&gdef.get_var_store(), nullptr,
1449 hb_array (coords, num_coords));
1450
1451 return g.find_variations_index (coords, num_coords, variations_index, &instancer);
1452 }
1453
1454
1455 /**
1456 * hb_ot_layout_feature_with_variations_get_lookups:
1457 * @face: #hb_face_t to work upon
1458 * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
1459 * @feature_index: The index of the feature to query
1460 * @variations_index: The index of the feature variation to query
1461 * @start_offset: offset of the first lookup to retrieve
1462 * @lookup_count: (inout) (optional): Input = the maximum number of lookups to return;
1463 * Output = the actual number of lookups returned (may be zero)
1464 * @lookup_indexes: (out) (array length=lookup_count): The array of lookups found for the query
1465 *
1466 * Fetches a list of all lookups enumerated for the specified feature, in
1467 * the specified face's GSUB table or GPOS table, enabled at the specified
1468 * variations index. The list returned will begin at the offset provided.
1469 *
1470 * Return value: Total number of lookups.
1471 *
1472 * Since: 1.4.0
1473 *
1474 **/
1475 unsigned int
hb_ot_layout_feature_with_variations_get_lookups(hb_face_t * face,hb_tag_t table_tag,unsigned int feature_index,unsigned int variations_index,unsigned int start_offset,unsigned int * lookup_count,unsigned int * lookup_indexes)1476 hb_ot_layout_feature_with_variations_get_lookups (hb_face_t *face,
1477 hb_tag_t table_tag,
1478 unsigned int feature_index,
1479 unsigned int variations_index,
1480 unsigned int start_offset,
1481 unsigned int *lookup_count /* IN/OUT */,
1482 unsigned int *lookup_indexes /* OUT */)
1483 {
1484 static_assert ((OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX), "");
1485 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1486
1487 const OT::Feature &f = g.get_feature_variation (feature_index, variations_index);
1488
1489 return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
1490 }
1491
1492
1493 /*
1494 * OT::GSUB
1495 */
1496
1497
1498 /**
1499 * hb_ot_layout_has_substitution:
1500 * @face: #hb_face_t to work upon
1501 *
1502 * Tests whether the specified face includes any GSUB substitutions.
1503 *
1504 * Return value: `true` if data found, `false` otherwise
1505 *
1506 * Since: 0.6.0
1507 *
1508 **/
1509 hb_bool_t
hb_ot_layout_has_substitution(hb_face_t * face)1510 hb_ot_layout_has_substitution (hb_face_t *face)
1511 {
1512 return face->table.GSUB->table->has_data ();
1513 }
1514
1515
1516 /**
1517 * hb_ot_layout_lookup_would_substitute:
1518 * @face: #hb_face_t to work upon
1519 * @lookup_index: The index of the lookup to query
1520 * @glyphs: The sequence of glyphs to query for substitution
1521 * @glyphs_length: The length of the glyph sequence
1522 * @zero_context: #hb_bool_t indicating whether pre-/post-context are disallowed
1523 * in substitutions
1524 *
1525 * Tests whether a specified lookup in the specified face would
1526 * trigger a substitution on the given glyph sequence.
1527 *
1528 * Return value: `true` if a substitution would be triggered, `false` otherwise
1529 *
1530 * Since: 0.9.7
1531 **/
1532 hb_bool_t
hb_ot_layout_lookup_would_substitute(hb_face_t * face,unsigned int lookup_index,const hb_codepoint_t * glyphs,unsigned int glyphs_length,hb_bool_t zero_context)1533 hb_ot_layout_lookup_would_substitute (hb_face_t *face,
1534 unsigned int lookup_index,
1535 const hb_codepoint_t *glyphs,
1536 unsigned int glyphs_length,
1537 hb_bool_t zero_context)
1538 {
1539 auto &gsub = face->table.GSUB;
1540 if (unlikely (lookup_index >= gsub->lookup_count)) return false;
1541 OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
1542
1543 const OT::SubstLookup& l = gsub->table->get_lookup (lookup_index);
1544 auto *accel = gsub->get_accel (lookup_index);
1545 return accel && l.would_apply (&c, accel);
1546 }
1547
1548
1549 /**
1550 * hb_ot_layout_substitute_start:
1551 * @font: #hb_font_t to use
1552 * @buffer: #hb_buffer_t buffer to work upon
1553 *
1554 * Called before substitution lookups are performed, to ensure that glyph
1555 * class and other properties are set on the glyphs in the buffer.
1556 *
1557 **/
1558 void
hb_ot_layout_substitute_start(hb_font_t * font,hb_buffer_t * buffer)1559 hb_ot_layout_substitute_start (hb_font_t *font,
1560 hb_buffer_t *buffer)
1561 {
1562 _hb_ot_layout_set_glyph_props (font, buffer);
1563 }
1564
1565 /**
1566 * hb_ot_layout_lookup_substitute_closure:
1567 * @face: #hb_face_t to work upon
1568 * @lookup_index: index of the feature lookup to query
1569 * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookup
1570 *
1571 * Compute the transitive closure of glyphs needed for a
1572 * specified lookup.
1573 *
1574 * Since: 0.9.7
1575 **/
1576 void
hb_ot_layout_lookup_substitute_closure(hb_face_t * face,unsigned int lookup_index,hb_set_t * glyphs)1577 hb_ot_layout_lookup_substitute_closure (hb_face_t *face,
1578 unsigned int lookup_index,
1579 hb_set_t *glyphs /* OUT */)
1580 {
1581 hb_map_t done_lookups_glyph_count;
1582 hb_hashmap_t<unsigned, hb::unique_ptr<hb_set_t>> done_lookups_glyph_set;
1583 OT::hb_closure_context_t c (face, glyphs, &done_lookups_glyph_count, &done_lookups_glyph_set);
1584
1585 const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
1586
1587 l.closure (&c, lookup_index);
1588 }
1589
1590 /**
1591 * hb_ot_layout_lookups_substitute_closure:
1592 * @face: #hb_face_t to work upon
1593 * @lookups: The set of lookups to query
1594 * @glyphs: (out): Array of glyphs comprising the transitive closure of the lookups
1595 *
1596 * Compute the transitive closure of glyphs needed for all of the
1597 * provided lookups.
1598 *
1599 * Since: 1.8.1
1600 **/
1601 void
hb_ot_layout_lookups_substitute_closure(hb_face_t * face,const hb_set_t * lookups,hb_set_t * glyphs)1602 hb_ot_layout_lookups_substitute_closure (hb_face_t *face,
1603 const hb_set_t *lookups,
1604 hb_set_t *glyphs /* OUT */)
1605 {
1606 hb_map_t done_lookups_glyph_count;
1607 hb_hashmap_t<unsigned, hb::unique_ptr<hb_set_t>> done_lookups_glyph_set;
1608 OT::hb_closure_context_t c (face, glyphs, &done_lookups_glyph_count, &done_lookups_glyph_set);
1609 const GSUB& gsub = *face->table.GSUB->table;
1610
1611 unsigned int iteration_count = 0;
1612 unsigned int glyphs_length;
1613 do
1614 {
1615 c.reset_lookup_visit_count ();
1616 glyphs_length = glyphs->get_population ();
1617 if (lookups)
1618 {
1619 for (auto lookup_index : *lookups)
1620 gsub.get_lookup (lookup_index).closure (&c, lookup_index);
1621 }
1622 else
1623 {
1624 for (unsigned int i = 0; i < gsub.get_lookup_count (); i++)
1625 gsub.get_lookup (i).closure (&c, i);
1626 }
1627 } while (iteration_count++ <= HB_CLOSURE_MAX_STAGES &&
1628 glyphs_length != glyphs->get_population ());
1629 }
1630
1631 /*
1632 * GPOS
1633 */
1634
1635
1636 /**
1637 * hb_ot_layout_has_positioning:
1638 * @face: #hb_face_t to work upon
1639 *
1640 * Tests whether the specified face includes any GPOS positioning.
1641 *
1642 * Return value: `true` if the face has GPOS data, `false` otherwise
1643 *
1644 **/
1645 hb_bool_t
hb_ot_layout_has_positioning(hb_face_t * face)1646 hb_ot_layout_has_positioning (hb_face_t *face)
1647 {
1648 return face->table.GPOS->table->has_data ();
1649 }
1650
1651 /**
1652 * hb_ot_layout_position_start:
1653 * @font: #hb_font_t to use
1654 * @buffer: #hb_buffer_t buffer to work upon
1655 *
1656 * Called before positioning lookups are performed, to ensure that glyph
1657 * attachment types and glyph-attachment chains are set for the glyphs in the buffer.
1658 *
1659 **/
1660 void
hb_ot_layout_position_start(hb_font_t * font,hb_buffer_t * buffer)1661 hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
1662 {
1663 GPOS::position_start (font, buffer);
1664 }
1665
1666
1667 /**
1668 * hb_ot_layout_position_finish_advances:
1669 * @font: #hb_font_t to use
1670 * @buffer: #hb_buffer_t buffer to work upon
1671 *
1672 * Called after positioning lookups are performed, to finish glyph advances.
1673 *
1674 **/
1675 void
hb_ot_layout_position_finish_advances(hb_font_t * font,hb_buffer_t * buffer)1676 hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
1677 {
1678 GPOS::position_finish_advances (font, buffer);
1679 }
1680
1681 /**
1682 * hb_ot_layout_position_finish_offsets:
1683 * @font: #hb_font_t to use
1684 * @buffer: #hb_buffer_t buffer to work upon
1685 *
1686 * Called after positioning lookups are performed, to finish glyph offsets.
1687 *
1688 **/
1689 void
hb_ot_layout_position_finish_offsets(hb_font_t * font,hb_buffer_t * buffer)1690 hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
1691 {
1692 GPOS::position_finish_offsets (font, buffer);
1693 }
1694
1695
1696 #ifndef HB_NO_LAYOUT_FEATURE_PARAMS
1697 /**
1698 * hb_ot_layout_get_size_params:
1699 * @face: #hb_face_t to work upon
1700 * @design_size: (out): The design size of the face
1701 * @subfamily_id: (out): The identifier of the face within the font subfamily
1702 * @subfamily_name_id: (out): The ‘name’ table name ID of the face within the font subfamily
1703 * @range_start: (out): The minimum size of the recommended size range for the face
1704 * @range_end: (out): The maximum size of the recommended size range for the face
1705 *
1706 * Fetches optical-size feature data (i.e., the `size` feature from GPOS). Note that
1707 * the subfamily_id and the subfamily name string (accessible via the subfamily_name_id)
1708 * as used here are defined as pertaining only to fonts within a font family that differ
1709 * specifically in their respective size ranges; other ways to differentiate fonts within
1710 * a subfamily are not covered by the `size` feature.
1711 *
1712 * For more information on this distinction, see the [`size` feature documentation](
1713 * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-size).
1714 *
1715 * Return value: `true` if data found, `false` otherwise
1716 *
1717 * Since: 0.9.10
1718 **/
1719 hb_bool_t
hb_ot_layout_get_size_params(hb_face_t * face,unsigned int * design_size,unsigned int * subfamily_id,hb_ot_name_id_t * subfamily_name_id,unsigned int * range_start,unsigned int * range_end)1720 hb_ot_layout_get_size_params (hb_face_t *face,
1721 unsigned int *design_size, /* OUT. May be NULL */
1722 unsigned int *subfamily_id, /* OUT. May be NULL */
1723 hb_ot_name_id_t *subfamily_name_id, /* OUT. May be NULL */
1724 unsigned int *range_start, /* OUT. May be NULL */
1725 unsigned int *range_end /* OUT. May be NULL */)
1726 {
1727 const GPOS &gpos = *face->table.GPOS->table;
1728 const hb_tag_t tag = HB_TAG ('s','i','z','e');
1729
1730 unsigned int num_features = gpos.get_feature_count ();
1731 for (unsigned int i = 0; i < num_features; i++)
1732 {
1733 if (tag == gpos.get_feature_tag (i))
1734 {
1735 const OT::Feature &f = gpos.get_feature (i);
1736 const OT::FeatureParamsSize ¶ms = f.get_feature_params ().get_size_params (tag);
1737
1738 if (params.designSize)
1739 {
1740 if (design_size) *design_size = params.designSize;
1741 if (subfamily_id) *subfamily_id = params.subfamilyID;
1742 if (subfamily_name_id) *subfamily_name_id = params.subfamilyNameID;
1743 if (range_start) *range_start = params.rangeStart;
1744 if (range_end) *range_end = params.rangeEnd;
1745
1746 return true;
1747 }
1748 }
1749 }
1750
1751 if (design_size) *design_size = 0;
1752 if (subfamily_id) *subfamily_id = 0;
1753 if (subfamily_name_id) *subfamily_name_id = HB_OT_NAME_ID_INVALID;
1754 if (range_start) *range_start = 0;
1755 if (range_end) *range_end = 0;
1756
1757 return false;
1758 }
1759
1760
1761 /**
1762 * hb_ot_layout_feature_get_name_ids:
1763 * @face: #hb_face_t to work upon
1764 * @table_tag: table tag to query, "GSUB" or "GPOS".
1765 * @feature_index: index of feature to query.
1766 * @label_id: (out) (optional): The ‘name’ table name ID that specifies a string
1767 * for a user-interface label for this feature. (May be NULL.)
1768 * @tooltip_id: (out) (optional): The ‘name’ table name ID that specifies a string
1769 * that an application can use for tooltip text for this
1770 * feature. (May be NULL.)
1771 * @sample_id: (out) (optional): The ‘name’ table name ID that specifies sample text
1772 * that illustrates the effect of this feature. (May be NULL.)
1773 * @num_named_parameters: (out) (optional): Number of named parameters. (May be zero.)
1774 * @first_param_id: (out) (optional): The first ‘name’ table name ID used to specify
1775 * strings for user-interface labels for the feature
1776 * parameters. (Must be zero if numParameters is zero.)
1777 *
1778 * Fetches name indices from feature parameters for "Stylistic Set" ('ssXX') or
1779 * "Character Variant" ('cvXX') features.
1780 *
1781 * Return value: `true` if data found, `false` otherwise
1782 *
1783 * Since: 2.0.0
1784 **/
1785 hb_bool_t
hb_ot_layout_feature_get_name_ids(hb_face_t * face,hb_tag_t table_tag,unsigned int feature_index,hb_ot_name_id_t * label_id,hb_ot_name_id_t * tooltip_id,hb_ot_name_id_t * sample_id,unsigned int * num_named_parameters,hb_ot_name_id_t * first_param_id)1786 hb_ot_layout_feature_get_name_ids (hb_face_t *face,
1787 hb_tag_t table_tag,
1788 unsigned int feature_index,
1789 hb_ot_name_id_t *label_id, /* OUT. May be NULL */
1790 hb_ot_name_id_t *tooltip_id, /* OUT. May be NULL */
1791 hb_ot_name_id_t *sample_id, /* OUT. May be NULL */
1792 unsigned int *num_named_parameters, /* OUT. May be NULL */
1793 hb_ot_name_id_t *first_param_id /* OUT. May be NULL */)
1794 {
1795 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1796
1797 hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1798 const OT::Feature &f = g.get_feature (feature_index);
1799
1800 const OT::FeatureParams &feature_params = f.get_feature_params ();
1801 if (&feature_params != &Null (OT::FeatureParams))
1802 {
1803 const OT::FeatureParamsStylisticSet& ss_params =
1804 feature_params.get_stylistic_set_params (feature_tag);
1805 if (&ss_params != &Null (OT::FeatureParamsStylisticSet)) /* ssXX */
1806 {
1807 if (label_id) *label_id = ss_params.uiNameID;
1808 // ssXX features don't have the rest
1809 if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1810 if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1811 if (num_named_parameters) *num_named_parameters = 0;
1812 if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1813 return true;
1814 }
1815 const OT::FeatureParamsCharacterVariants& cv_params =
1816 feature_params.get_character_variants_params (feature_tag);
1817 if (&cv_params != &Null (OT::FeatureParamsCharacterVariants)) /* cvXX */
1818 {
1819 if (label_id) *label_id = cv_params.featUILableNameID;
1820 if (tooltip_id) *tooltip_id = cv_params.featUITooltipTextNameID;
1821 if (sample_id) *sample_id = cv_params.sampleTextNameID;
1822 if (num_named_parameters) *num_named_parameters = cv_params.numNamedParameters;
1823 if (first_param_id) *first_param_id = cv_params.firstParamUILabelNameID;
1824 return true;
1825 }
1826 }
1827
1828 if (label_id) *label_id = HB_OT_NAME_ID_INVALID;
1829 if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1830 if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1831 if (num_named_parameters) *num_named_parameters = 0;
1832 if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1833 return false;
1834 }
1835 /**
1836 * hb_ot_layout_feature_get_characters:
1837 * @face: #hb_face_t to work upon
1838 * @table_tag: table tag to query, "GSUB" or "GPOS".
1839 * @feature_index: index of feature to query.
1840 * @start_offset: offset of the first character to retrieve
1841 * @char_count: (inout) (optional): Input = the maximum number of characters to return;
1842 * Output = the actual number of characters returned (may be zero)
1843 * @characters: (out caller-allocates) (array length=char_count): A buffer pointer.
1844 * The Unicode codepoints of the characters for which this feature provides
1845 * glyph variants.
1846 *
1847 * Fetches a list of the characters defined as having a variant under the specified
1848 * "Character Variant" ("cvXX") feature tag.
1849 *
1850 * Return value: Number of total sample characters in the cvXX feature.
1851 *
1852 * Since: 2.0.0
1853 **/
1854 unsigned int
hb_ot_layout_feature_get_characters(hb_face_t * face,hb_tag_t table_tag,unsigned int feature_index,unsigned int start_offset,unsigned int * char_count,hb_codepoint_t * characters)1855 hb_ot_layout_feature_get_characters (hb_face_t *face,
1856 hb_tag_t table_tag,
1857 unsigned int feature_index,
1858 unsigned int start_offset,
1859 unsigned int *char_count, /* IN/OUT. May be NULL */
1860 hb_codepoint_t *characters /* OUT. May be NULL */)
1861 {
1862 const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1863 return g.get_feature (feature_index)
1864 .get_feature_params ()
1865 .get_character_variants_params(g.get_feature_tag (feature_index))
1866 .get_characters (start_offset, char_count, characters);
1867 }
1868 #endif
1869
1870
1871 /*
1872 * Parts of different types are implemented here such that they have direct
1873 * access to GSUB/GPOS lookups.
1874 */
1875
1876
1877 struct GSUBProxy
1878 {
1879 static constexpr unsigned table_index = 0u;
1880 static constexpr bool always_inplace = false;
1881 typedef OT::SubstLookup Lookup;
1882
GSUBProxyGSUBProxy1883 GSUBProxy (hb_face_t *face) :
1884 accel (*face->table.GSUB) {}
1885
1886 const GSUB::accelerator_t &accel;
1887 };
1888
1889 struct GPOSProxy
1890 {
1891 static constexpr unsigned table_index = 1u;
1892 static constexpr bool always_inplace = true;
1893 typedef OT::PosLookup Lookup;
1894
GPOSProxyGPOSProxy1895 GPOSProxy (hb_face_t *face) :
1896 accel (*face->table.GPOS) {}
1897
1898 const GPOS::accelerator_t &accel;
1899 };
1900
1901
1902 static inline bool
apply_forward(OT::hb_ot_apply_context_t * c,const OT::hb_ot_layout_lookup_accelerator_t & accel,unsigned subtable_count)1903 apply_forward (OT::hb_ot_apply_context_t *c,
1904 const OT::hb_ot_layout_lookup_accelerator_t &accel,
1905 unsigned subtable_count)
1906 {
1907 bool use_cache = accel.cache_enter (c);
1908
1909 bool ret = false;
1910 hb_buffer_t *buffer = c->buffer;
1911 while (buffer->idx < buffer->len && buffer->successful)
1912 {
1913 bool applied = false;
1914 if (accel.digest.may_have (buffer->cur().codepoint) &&
1915 (buffer->cur().mask & c->lookup_mask) &&
1916 c->check_glyph_property (&buffer->cur(), c->lookup_props))
1917 {
1918 applied = accel.apply (c, subtable_count, use_cache);
1919 }
1920
1921 if (applied)
1922 ret = true;
1923 else
1924 (void) buffer->next_glyph ();
1925 }
1926
1927 if (use_cache)
1928 accel.cache_leave (c);
1929
1930 return ret;
1931 }
1932
1933 static inline bool
apply_backward(OT::hb_ot_apply_context_t * c,const OT::hb_ot_layout_lookup_accelerator_t & accel,unsigned subtable_count)1934 apply_backward (OT::hb_ot_apply_context_t *c,
1935 const OT::hb_ot_layout_lookup_accelerator_t &accel,
1936 unsigned subtable_count)
1937 {
1938 bool ret = false;
1939 hb_buffer_t *buffer = c->buffer;
1940 do
1941 {
1942 if (accel.digest.may_have (buffer->cur().codepoint) &&
1943 (buffer->cur().mask & c->lookup_mask) &&
1944 c->check_glyph_property (&buffer->cur(), c->lookup_props))
1945 ret |= accel.apply (c, subtable_count, false);
1946
1947 /* The reverse lookup doesn't "advance" cursor (for good reason). */
1948 buffer->idx--;
1949
1950 }
1951 while ((int) buffer->idx >= 0);
1952 return ret;
1953 }
1954
1955 template <typename Proxy>
1956 static inline bool
apply_string(OT::hb_ot_apply_context_t * c,const typename Proxy::Lookup & lookup,const OT::hb_ot_layout_lookup_accelerator_t & accel)1957 apply_string (OT::hb_ot_apply_context_t *c,
1958 const typename Proxy::Lookup &lookup,
1959 const OT::hb_ot_layout_lookup_accelerator_t &accel)
1960 {
1961 hb_buffer_t *buffer = c->buffer;
1962 unsigned subtable_count = lookup.get_subtable_count ();
1963
1964 if (unlikely (!buffer->len || !c->lookup_mask))
1965 return false;
1966
1967 bool ret = false;
1968
1969 c->set_lookup_props (lookup.get_props ());
1970
1971 if (likely (!lookup.is_reverse ()))
1972 {
1973 /* in/out forward substitution/positioning */
1974 if (!Proxy::always_inplace)
1975 buffer->clear_output ();
1976
1977 buffer->idx = 0;
1978 ret = apply_forward (c, accel, subtable_count);
1979
1980 if (!Proxy::always_inplace)
1981 buffer->sync ();
1982 }
1983 else
1984 {
1985 /* in-place backward substitution/positioning */
1986 assert (!buffer->have_output);
1987 buffer->idx = buffer->len - 1;
1988 ret = apply_backward (c, accel, subtable_count);
1989 }
1990
1991 return ret;
1992 }
1993
1994 template <typename Proxy>
apply(const Proxy & proxy,const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const1995 inline void hb_ot_map_t::apply (const Proxy &proxy,
1996 const hb_ot_shape_plan_t *plan,
1997 hb_font_t *font,
1998 hb_buffer_t *buffer) const
1999 {
2000 const unsigned int table_index = proxy.table_index;
2001 unsigned int i = 0;
2002 OT::hb_ot_apply_context_t c (table_index, font, buffer, proxy.accel.get_blob ());
2003 c.set_recurse_func (Proxy::Lookup::template dispatch_recurse_func<OT::hb_ot_apply_context_t>);
2004
2005 for (unsigned int stage_index = 0; stage_index < stages[table_index].length; stage_index++)
2006 {
2007 const stage_map_t *stage = &stages[table_index][stage_index];
2008 for (; i < stage->last_lookup; i++)
2009 {
2010 auto &lookup = lookups[table_index][i];
2011
2012 unsigned int lookup_index = lookup.index;
2013
2014 auto *accel = proxy.accel.get_accel (lookup_index);
2015 if (unlikely (!accel)) continue;
2016
2017 if (buffer->messaging () &&
2018 !buffer->message (font, "start lookup %u feature '%c%c%c%c'", lookup_index, HB_UNTAG (lookup.feature_tag))) continue;
2019
2020 /* c.digest is a digest of all the current glyphs in the buffer
2021 * (plus some past glyphs).
2022 *
2023 * Only try applying the lookup if there is any overlap. */
2024 if (accel->digest.may_have (c.digest))
2025 {
2026 c.set_lookup_index (lookup_index);
2027 c.set_lookup_mask (lookup.mask, false);
2028 c.set_auto_zwj (lookup.auto_zwj, false);
2029 c.set_auto_zwnj (lookup.auto_zwnj, false);
2030 c.set_random (lookup.random);
2031 c.set_per_syllable (lookup.per_syllable, false);
2032 /* apply_string's set_lookup_props initializes the iterators. */
2033
2034 apply_string<Proxy> (&c,
2035 proxy.accel.table->get_lookup (lookup_index),
2036 *accel);
2037 }
2038 else if (buffer->messaging ())
2039 (void) buffer->message (font, "skipped lookup %u feature '%c%c%c%c' because no glyph matches", lookup_index, HB_UNTAG (lookup.feature_tag));
2040
2041 if (buffer->messaging ())
2042 (void) buffer->message (font, "end lookup %u feature '%c%c%c%c'", lookup_index, HB_UNTAG (lookup.feature_tag));
2043 }
2044
2045 if (stage->pause_func)
2046 {
2047 if (stage->pause_func (plan, font, buffer))
2048 {
2049 /* Refresh working buffer digest since buffer changed. */
2050 c.digest = buffer->digest ();
2051 }
2052 }
2053 }
2054 }
2055
substitute(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const2056 void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
2057 {
2058 GSUBProxy proxy (font->face);
2059 if (buffer->messaging () &&
2060 !buffer->message (font, "start table GSUB script tag '%c%c%c%c'", HB_UNTAG (chosen_script[0]))) return;
2061 apply (proxy, plan, font, buffer);
2062 if (buffer->messaging ())
2063 (void) buffer->message (font, "end table GSUB script tag '%c%c%c%c'", HB_UNTAG (chosen_script[0]));
2064 }
2065
position(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const2066 void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
2067 {
2068 GPOSProxy proxy (font->face);
2069 if (buffer->messaging () &&
2070 !buffer->message (font, "start table GPOS script tag '%c%c%c%c'", HB_UNTAG (chosen_script[1]))) return;
2071 apply (proxy, plan, font, buffer);
2072 if (buffer->messaging ())
2073 (void) buffer->message (font, "end table GPOS script tag '%c%c%c%c'", HB_UNTAG (chosen_script[1]));
2074 }
2075
2076 void
hb_ot_layout_substitute_lookup(OT::hb_ot_apply_context_t * c,const OT::SubstLookup & lookup,const OT::hb_ot_layout_lookup_accelerator_t & accel)2077 hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
2078 const OT::SubstLookup &lookup,
2079 const OT::hb_ot_layout_lookup_accelerator_t &accel)
2080 {
2081 apply_string<GSUBProxy> (c, lookup, accel);
2082 }
2083
2084 #ifndef HB_NO_BASE
2085
2086 static void
choose_base_tags(hb_script_t script,hb_language_t language,hb_tag_t * script_tag,hb_tag_t * language_tag)2087 choose_base_tags (hb_script_t script,
2088 hb_language_t language,
2089 hb_tag_t *script_tag,
2090 hb_tag_t *language_tag)
2091 {
2092 hb_tag_t script_tags[HB_OT_MAX_TAGS_PER_SCRIPT];
2093 unsigned script_count = ARRAY_LENGTH (script_tags);
2094
2095 hb_tag_t language_tags[HB_OT_MAX_TAGS_PER_LANGUAGE];
2096 unsigned language_count = ARRAY_LENGTH (language_tags);
2097
2098 hb_ot_tags_from_script_and_language (script, language,
2099 &script_count, script_tags,
2100 &language_count, language_tags);
2101
2102 *script_tag = script_count ? script_tags[script_count - 1] : HB_OT_TAG_DEFAULT_SCRIPT;
2103 *language_tag = language_count ? language_tags[language_count - 1] : HB_OT_TAG_DEFAULT_LANGUAGE;
2104 }
2105
2106 /**
2107 * hb_ot_layout_get_font_extents:
2108 * @font: a font
2109 * @direction: text direction.
2110 * @script_tag: script tag.
2111 * @language_tag: language tag.
2112 * @extents: (out) (nullable): font extents if found.
2113 *
2114 * Fetches script/language-specific font extents. These values are
2115 * looked up in the `BASE` table's `MinMax` records.
2116 *
2117 * If no such extents are found, the default extents for the font are
2118 * fetched. As such, the return value of this function can for the
2119 * most part be ignored. Note that the per-script/language extents
2120 * do not have a line-gap value, and the line-gap is set to zero in
2121 * that case.
2122 *
2123 * Return value: `true` if found script/language-specific font extents.
2124 *
2125 * Since: 8.0.0
2126 **/
2127 hb_bool_t
hb_ot_layout_get_font_extents(hb_font_t * font,hb_direction_t direction,hb_tag_t script_tag,hb_tag_t language_tag,hb_font_extents_t * extents)2128 hb_ot_layout_get_font_extents (hb_font_t *font,
2129 hb_direction_t direction,
2130 hb_tag_t script_tag,
2131 hb_tag_t language_tag,
2132 hb_font_extents_t *extents)
2133 {
2134 hb_position_t min = 0, max = 0;
2135 if (font->face->table.BASE->get_min_max (font, direction, script_tag, language_tag, HB_TAG_NONE,
2136 &min, &max))
2137 {
2138 if (extents)
2139 {
2140 extents->ascender = max;
2141 extents->descender = min;
2142 extents->line_gap = 0;
2143 }
2144 return true;
2145 }
2146
2147 hb_font_get_extents_for_direction (font, direction, extents);
2148 return false;
2149 }
2150
2151 /**
2152 * hb_ot_layout_get_font_extents2:
2153 * @font: a font
2154 * @direction: text direction.
2155 * @script: script.
2156 * @language: (nullable): language.
2157 * @extents: (out) (nullable): font extents if found.
2158 *
2159 * Fetches script/language-specific font extents. These values are
2160 * looked up in the `BASE` table's `MinMax` records.
2161 *
2162 * If no such extents are found, the default extents for the font are
2163 * fetched. As such, the return value of this function can for the
2164 * most part be ignored. Note that the per-script/language extents
2165 * do not have a line-gap value, and the line-gap is set to zero in
2166 * that case.
2167 *
2168 * This function is like hb_ot_layout_get_font_extents() but takes
2169 * #hb_script_t and #hb_language_t instead of OpenType #hb_tag_t.
2170 *
2171 * Return value: `true` if found script/language-specific font extents.
2172 *
2173 * Since: 8.0.0
2174 **/
2175 hb_bool_t
hb_ot_layout_get_font_extents2(hb_font_t * font,hb_direction_t direction,hb_script_t script,hb_language_t language,hb_font_extents_t * extents)2176 hb_ot_layout_get_font_extents2 (hb_font_t *font,
2177 hb_direction_t direction,
2178 hb_script_t script,
2179 hb_language_t language,
2180 hb_font_extents_t *extents)
2181 {
2182 hb_tag_t script_tag, language_tag;
2183 choose_base_tags (script, language, &script_tag, &language_tag);
2184 return hb_ot_layout_get_font_extents (font,
2185 direction,
2186 script_tag,
2187 language_tag,
2188 extents);
2189 }
2190
2191 /**
2192 * hb_ot_layout_get_horizontal_baseline_tag_for_script:
2193 * @script: a script tag.
2194 *
2195 * Fetches the dominant horizontal baseline tag used by @script.
2196 *
2197 * Return value: dominant baseline tag for the @script.
2198 *
2199 * Since: 4.0.0
2200 **/
2201 hb_ot_layout_baseline_tag_t
hb_ot_layout_get_horizontal_baseline_tag_for_script(hb_script_t script)2202 hb_ot_layout_get_horizontal_baseline_tag_for_script (hb_script_t script)
2203 {
2204 /* Keep in sync with hb_ot_layout_get_baseline_with_fallback */
2205 switch ((int) script)
2206 {
2207 /* Unicode-1.1 additions */
2208 case HB_SCRIPT_BENGALI:
2209 case HB_SCRIPT_DEVANAGARI:
2210 case HB_SCRIPT_GUJARATI:
2211 case HB_SCRIPT_GURMUKHI:
2212 /* Unicode-2.0 additions */
2213 case HB_SCRIPT_TIBETAN:
2214 /* Unicode-4.0 additions */
2215 case HB_SCRIPT_LIMBU:
2216 /* Unicode-4.1 additions */
2217 case HB_SCRIPT_SYLOTI_NAGRI:
2218 /* Unicode-5.0 additions */
2219 case HB_SCRIPT_PHAGS_PA:
2220 /* Unicode-5.2 additions */
2221 case HB_SCRIPT_MEETEI_MAYEK:
2222 /* Unicode-6.1 additions */
2223 case HB_SCRIPT_SHARADA:
2224 case HB_SCRIPT_TAKRI:
2225 /* Unicode-7.0 additions */
2226 case HB_SCRIPT_MODI:
2227 case HB_SCRIPT_SIDDHAM:
2228 case HB_SCRIPT_TIRHUTA:
2229 /* Unicode-9.0 additions */
2230 case HB_SCRIPT_MARCHEN:
2231 case HB_SCRIPT_NEWA:
2232 /* Unicode-10.0 additions */
2233 case HB_SCRIPT_SOYOMBO:
2234 case HB_SCRIPT_ZANABAZAR_SQUARE:
2235 /* Unicode-11.0 additions */
2236 case HB_SCRIPT_DOGRA:
2237 case HB_SCRIPT_GUNJALA_GONDI:
2238 /* Unicode-12.0 additions */
2239 case HB_SCRIPT_NANDINAGARI:
2240 return HB_OT_LAYOUT_BASELINE_TAG_HANGING;
2241
2242 /* Unicode-1.1 additions */
2243 case HB_SCRIPT_HANGUL:
2244 case HB_SCRIPT_HAN:
2245 case HB_SCRIPT_HIRAGANA:
2246 case HB_SCRIPT_KATAKANA:
2247 /* Unicode-3.0 additions */
2248 case HB_SCRIPT_BOPOMOFO:
2249 /* Unicode-9.0 additions */
2250 case HB_SCRIPT_TANGUT:
2251 /* Unicode-10.0 additions */
2252 case HB_SCRIPT_NUSHU:
2253 /* Unicode-13.0 additions */
2254 case HB_SCRIPT_KHITAN_SMALL_SCRIPT:
2255 return HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT;
2256
2257 default:
2258 return HB_OT_LAYOUT_BASELINE_TAG_ROMAN;
2259 }
2260 }
2261
2262 /**
2263 * hb_ot_layout_get_baseline:
2264 * @font: a font
2265 * @baseline_tag: a baseline tag
2266 * @direction: text direction.
2267 * @script_tag: script tag.
2268 * @language_tag: language tag, currently unused.
2269 * @coord: (out) (nullable): baseline value if found.
2270 *
2271 * Fetches a baseline value from the face.
2272 *
2273 * Return value: `true` if found baseline value in the font.
2274 *
2275 * Since: 2.6.0
2276 **/
2277 hb_bool_t
hb_ot_layout_get_baseline(hb_font_t * font,hb_ot_layout_baseline_tag_t baseline_tag,hb_direction_t direction,hb_tag_t script_tag,hb_tag_t language_tag,hb_position_t * coord)2278 hb_ot_layout_get_baseline (hb_font_t *font,
2279 hb_ot_layout_baseline_tag_t baseline_tag,
2280 hb_direction_t direction,
2281 hb_tag_t script_tag,
2282 hb_tag_t language_tag,
2283 hb_position_t *coord /* OUT. May be NULL. */)
2284 {
2285 return font->face->table.BASE->get_baseline (font, baseline_tag, direction, script_tag, language_tag, coord);
2286 }
2287
2288 /**
2289 * hb_ot_layout_get_baseline2:
2290 * @font: a font
2291 * @baseline_tag: a baseline tag
2292 * @direction: text direction.
2293 * @script: script.
2294 * @language: (nullable): language, currently unused.
2295 * @coord: (out) (nullable): baseline value if found.
2296 *
2297 * Fetches a baseline value from the face.
2298 *
2299 * This function is like hb_ot_layout_get_baseline() but takes
2300 * #hb_script_t and #hb_language_t instead of OpenType #hb_tag_t.
2301 *
2302 * Return value: `true` if found baseline value in the font.
2303 *
2304 * Since: 8.0.0
2305 **/
2306 hb_bool_t
hb_ot_layout_get_baseline2(hb_font_t * font,hb_ot_layout_baseline_tag_t baseline_tag,hb_direction_t direction,hb_script_t script,hb_language_t language,hb_position_t * coord)2307 hb_ot_layout_get_baseline2 (hb_font_t *font,
2308 hb_ot_layout_baseline_tag_t baseline_tag,
2309 hb_direction_t direction,
2310 hb_script_t script,
2311 hb_language_t language,
2312 hb_position_t *coord /* OUT. May be NULL. */)
2313 {
2314 hb_tag_t script_tag, language_tag;
2315 choose_base_tags (script, language, &script_tag, &language_tag);
2316 return hb_ot_layout_get_baseline (font,
2317 baseline_tag,
2318 direction,
2319 script_tag,
2320 language_tag,
2321 coord);
2322 }
2323
2324 /**
2325 * hb_ot_layout_get_baseline_with_fallback:
2326 * @font: a font
2327 * @baseline_tag: a baseline tag
2328 * @direction: text direction.
2329 * @script_tag: script tag.
2330 * @language_tag: language tag, currently unused.
2331 * @coord: (out): baseline value if found.
2332 *
2333 * Fetches a baseline value from the face, and synthesizes
2334 * it if the font does not have it.
2335 *
2336 * Since: 4.0.0
2337 **/
2338 void
hb_ot_layout_get_baseline_with_fallback(hb_font_t * font,hb_ot_layout_baseline_tag_t baseline_tag,hb_direction_t direction,hb_tag_t script_tag,hb_tag_t language_tag,hb_position_t * coord)2339 hb_ot_layout_get_baseline_with_fallback (hb_font_t *font,
2340 hb_ot_layout_baseline_tag_t baseline_tag,
2341 hb_direction_t direction,
2342 hb_tag_t script_tag,
2343 hb_tag_t language_tag,
2344 hb_position_t *coord /* OUT */)
2345 {
2346 if (hb_ot_layout_get_baseline (font,
2347 baseline_tag,
2348 direction,
2349 script_tag,
2350 language_tag,
2351 coord))
2352 return;
2353
2354 /* Synthesize missing baselines.
2355 * See https://www.w3.org/TR/css-inline-3/#baseline-synthesis-fonts
2356 */
2357 switch (baseline_tag)
2358 {
2359 case HB_OT_LAYOUT_BASELINE_TAG_ROMAN:
2360 *coord = 0; // FIXME origin ?
2361 break;
2362
2363 case HB_OT_LAYOUT_BASELINE_TAG_MATH:
2364 {
2365 hb_codepoint_t glyph;
2366 hb_glyph_extents_t extents;
2367 if (HB_DIRECTION_IS_HORIZONTAL (direction) &&
2368 (hb_font_get_nominal_glyph (font, 0x2212u, &glyph) ||
2369 hb_font_get_nominal_glyph (font, '-', &glyph)) &&
2370 hb_font_get_glyph_extents (font, glyph, &extents))
2371 {
2372 *coord = extents.y_bearing + extents.height / 2;
2373 }
2374 else
2375 {
2376 hb_position_t x_height = font->y_scale / 2;
2377 #ifndef HB_NO_METRICS
2378 hb_ot_metrics_get_position_with_fallback (font, HB_OT_METRICS_TAG_X_HEIGHT, &x_height);
2379 #endif
2380 *coord = x_height / 2;
2381 }
2382 }
2383 break;
2384
2385 case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT:
2386 case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT:
2387 {
2388 hb_position_t embox_top, embox_bottom;
2389
2390 hb_ot_layout_get_baseline_with_fallback (font,
2391 HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT,
2392 direction,
2393 script_tag,
2394 language_tag,
2395 &embox_top);
2396 hb_ot_layout_get_baseline_with_fallback (font,
2397 HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT,
2398 direction,
2399 script_tag,
2400 language_tag,
2401 &embox_bottom);
2402
2403 if (baseline_tag == HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT)
2404 *coord = embox_top + (embox_bottom - embox_top) / 10;
2405 else
2406 *coord = embox_bottom + (embox_top - embox_bottom) / 10;
2407 }
2408 break;
2409
2410 case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT:
2411 if (hb_ot_layout_get_baseline (font,
2412 HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT,
2413 direction,
2414 script_tag,
2415 language_tag,
2416 coord))
2417 *coord += HB_DIRECTION_IS_HORIZONTAL (direction) ? font->y_scale : font->x_scale;
2418 else
2419 {
2420 hb_font_extents_t font_extents;
2421 hb_font_get_extents_for_direction (font, direction, &font_extents);
2422 *coord = font_extents.ascender;
2423 }
2424 break;
2425
2426 case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT:
2427 if (hb_ot_layout_get_baseline (font,
2428 HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT,
2429 direction,
2430 script_tag,
2431 language_tag,
2432 coord))
2433 *coord -= HB_DIRECTION_IS_HORIZONTAL (direction) ? font->y_scale : font->x_scale;
2434 else
2435 {
2436 hb_font_extents_t font_extents;
2437 hb_font_get_extents_for_direction (font, direction, &font_extents);
2438 *coord = font_extents.descender;
2439 }
2440 break;
2441
2442 case HB_OT_LAYOUT_BASELINE_TAG_HANGING:
2443 if (HB_DIRECTION_IS_HORIZONTAL (direction))
2444 {
2445 hb_codepoint_t ch;
2446 hb_codepoint_t glyph;
2447 hb_glyph_extents_t extents;
2448
2449 /* Keep in sync with hb_ot_layout_get_horizontal_baseline_for_script */
2450 switch ((int) script_tag)
2451 {
2452 /* Unicode-1.1 additions */
2453 case HB_SCRIPT_BENGALI: ch = 0x0995u; break;
2454 case HB_SCRIPT_DEVANAGARI: ch = 0x0915u; break;
2455 case HB_SCRIPT_GUJARATI: ch = 0x0a95u; break;
2456 case HB_SCRIPT_GURMUKHI: ch = 0x0a15u; break;
2457 /* Unicode-2.0 additions */
2458 case HB_SCRIPT_TIBETAN: ch = 0x0f40u; break;
2459 /* Unicode-4.0 additions */
2460 case HB_SCRIPT_LIMBU: ch = 0x1901u; break;
2461 /* Unicode-4.1 additions */
2462 case HB_SCRIPT_SYLOTI_NAGRI: ch = 0xa807u; break;
2463 /* Unicode-5.0 additions */
2464 case HB_SCRIPT_PHAGS_PA: ch = 0xa840u; break;
2465 /* Unicode-5.2 additions */
2466 case HB_SCRIPT_MEETEI_MAYEK: ch = 0xabc0u; break;
2467 /* Unicode-6.1 additions */
2468 case HB_SCRIPT_SHARADA: ch = 0x11191u; break;
2469 case HB_SCRIPT_TAKRI: ch = 0x1168cu; break;
2470 /* Unicode-7.0 additions */
2471 case HB_SCRIPT_MODI: ch = 0x1160eu;break;
2472 case HB_SCRIPT_SIDDHAM: ch = 0x11590u; break;
2473 case HB_SCRIPT_TIRHUTA: ch = 0x1148fu; break;
2474 /* Unicode-9.0 additions */
2475 case HB_SCRIPT_MARCHEN: ch = 0x11c72u; break;
2476 case HB_SCRIPT_NEWA: ch = 0x1140eu; break;
2477 /* Unicode-10.0 additions */
2478 case HB_SCRIPT_SOYOMBO: ch = 0x11a5cu; break;
2479 case HB_SCRIPT_ZANABAZAR_SQUARE: ch = 0x11a0bu; break;
2480 /* Unicode-11.0 additions */
2481 case HB_SCRIPT_DOGRA: ch = 0x1180au; break;
2482 case HB_SCRIPT_GUNJALA_GONDI: ch = 0x11d6cu; break;
2483 /* Unicode-12.0 additions */
2484 case HB_SCRIPT_NANDINAGARI: ch = 0x119b0u; break;
2485 default: ch = 0; break;
2486 }
2487
2488 if (ch &&
2489 hb_font_get_nominal_glyph (font, ch, &glyph) &&
2490 hb_font_get_glyph_extents (font, glyph, &extents))
2491 *coord = extents.y_bearing;
2492 else
2493 *coord = font->y_scale * 6 / 10; // FIXME makes assumptions about origin
2494 }
2495 else
2496 *coord = font->x_scale * 6 / 10; // FIXME makes assumptions about origin
2497 break;
2498
2499 case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_CENTRAL:
2500 {
2501 hb_position_t top, bottom;
2502 hb_ot_layout_get_baseline_with_fallback (font,
2503 HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT,
2504 direction,
2505 script_tag,
2506 language_tag,
2507 &top);
2508 hb_ot_layout_get_baseline_with_fallback (font,
2509 HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT,
2510 direction,
2511 script_tag,
2512 language_tag,
2513 &bottom);
2514 *coord = (top + bottom) / 2;
2515
2516 }
2517 break;
2518
2519 case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_CENTRAL:
2520 {
2521 hb_position_t top, bottom;
2522 hb_ot_layout_get_baseline_with_fallback (font,
2523 HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT,
2524 direction,
2525 script_tag,
2526 language_tag,
2527 &top);
2528 hb_ot_layout_get_baseline_with_fallback (font,
2529 HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT,
2530 direction,
2531 script_tag,
2532 language_tag,
2533 &bottom);
2534 *coord = (top + bottom) / 2;
2535
2536 }
2537 break;
2538
2539 case _HB_OT_LAYOUT_BASELINE_TAG_MAX_VALUE:
2540 default:
2541 *coord = 0;
2542 break;
2543 }
2544 }
2545
2546 /**
2547 * hb_ot_layout_get_baseline_with_fallback2:
2548 * @font: a font
2549 * @baseline_tag: a baseline tag
2550 * @direction: text direction.
2551 * @script: script.
2552 * @language: (nullable): language, currently unused.
2553 * @coord: (out): baseline value if found.
2554 *
2555 * Fetches a baseline value from the face, and synthesizes
2556 * it if the font does not have it.
2557 *
2558 * This function is like hb_ot_layout_get_baseline_with_fallback() but takes
2559 * #hb_script_t and #hb_language_t instead of OpenType #hb_tag_t.
2560 *
2561 * Since: 8.0.0
2562 **/
2563 void
hb_ot_layout_get_baseline_with_fallback2(hb_font_t * font,hb_ot_layout_baseline_tag_t baseline_tag,hb_direction_t direction,hb_script_t script,hb_language_t language,hb_position_t * coord)2564 hb_ot_layout_get_baseline_with_fallback2 (hb_font_t *font,
2565 hb_ot_layout_baseline_tag_t baseline_tag,
2566 hb_direction_t direction,
2567 hb_script_t script,
2568 hb_language_t language,
2569 hb_position_t *coord /* OUT */)
2570 {
2571 hb_tag_t script_tag, language_tag;
2572 choose_base_tags (script, language, &script_tag, &language_tag);
2573 hb_ot_layout_get_baseline_with_fallback (font,
2574 baseline_tag,
2575 direction,
2576 script_tag,
2577 language_tag,
2578 coord);
2579 }
2580
2581 #endif
2582
2583
2584 struct hb_get_glyph_alternates_dispatch_t :
2585 hb_dispatch_context_t<hb_get_glyph_alternates_dispatch_t, unsigned>
2586 {
default_return_valuehb_get_glyph_alternates_dispatch_t2587 static return_t default_return_value () { return 0; }
stop_sublookup_iterationhb_get_glyph_alternates_dispatch_t2588 bool stop_sublookup_iteration (return_t r) const { return r; }
2589
2590 private:
2591 template <typename T, typename ...Ts> auto
2592 _dispatch (const T &obj, hb_priority<1>, Ts&&... ds) HB_AUTO_RETURN
2593 ( obj.get_glyph_alternates (std::forward<Ts> (ds)...) )
2594 template <typename T, typename ...Ts> auto
2595 _dispatch (const T &obj, hb_priority<0>, Ts&&... ds) HB_AUTO_RETURN
2596 ( default_return_value () )
2597 public:
2598 template <typename T, typename ...Ts> auto
2599 dispatch (const T &obj, Ts&&... ds) HB_AUTO_RETURN
2600 ( _dispatch (obj, hb_prioritize, std::forward<Ts> (ds)...) )
2601 };
2602
2603 #ifndef HB_NO_LAYOUT_RARELY_USED
2604 /**
2605 * hb_ot_layout_lookup_get_glyph_alternates:
2606 * @face: a face.
2607 * @lookup_index: index of the feature lookup to query.
2608 * @glyph: a glyph id.
2609 * @start_offset: starting offset.
2610 * @alternate_count: (inout) (optional): Input = the maximum number of alternate glyphs to return;
2611 * Output = the actual number of alternate glyphs returned (may be zero).
2612 * @alternate_glyphs: (out caller-allocates) (array length=alternate_count): A glyphs buffer.
2613 * Alternate glyphs associated with the glyph id.
2614 *
2615 * Fetches alternates of a glyph from a given GSUB lookup index.
2616 *
2617 * Return value: Total number of alternates found in the specific lookup index for the given glyph id.
2618 *
2619 * Since: 2.6.8
2620 **/
2621 HB_EXTERN unsigned
hb_ot_layout_lookup_get_glyph_alternates(hb_face_t * face,unsigned lookup_index,hb_codepoint_t glyph,unsigned start_offset,unsigned * alternate_count,hb_codepoint_t * alternate_glyphs)2622 hb_ot_layout_lookup_get_glyph_alternates (hb_face_t *face,
2623 unsigned lookup_index,
2624 hb_codepoint_t glyph,
2625 unsigned start_offset,
2626 unsigned *alternate_count /* IN/OUT. May be NULL. */,
2627 hb_codepoint_t *alternate_glyphs /* OUT. May be NULL. */)
2628 {
2629 hb_get_glyph_alternates_dispatch_t c;
2630 const OT::SubstLookup &lookup = face->table.GSUB->table->get_lookup (lookup_index);
2631 auto ret = lookup.dispatch (&c, glyph, start_offset, alternate_count, alternate_glyphs);
2632 if (!ret && alternate_count) *alternate_count = 0;
2633 return ret;
2634 }
2635
2636
2637 struct hb_position_single_dispatch_t :
2638 hb_dispatch_context_t<hb_position_single_dispatch_t, bool>
2639 {
default_return_valuehb_position_single_dispatch_t2640 static return_t default_return_value () { return false; }
stop_sublookup_iterationhb_position_single_dispatch_t2641 bool stop_sublookup_iteration (return_t r) const { return r; }
2642
2643 private:
2644 template <typename T, typename ...Ts> auto
2645 _dispatch (const T &obj, hb_priority<1>, Ts&&... ds) HB_AUTO_RETURN
2646 ( obj.position_single (std::forward<Ts> (ds)...) )
2647 template <typename T, typename ...Ts> auto
2648 _dispatch (const T &obj, hb_priority<0>, Ts&&... ds) HB_AUTO_RETURN
2649 ( default_return_value () )
2650 public:
2651 template <typename T, typename ...Ts> auto
2652 dispatch (const T &obj, Ts&&... ds) HB_AUTO_RETURN
2653 ( _dispatch (obj, hb_prioritize, std::forward<Ts> (ds)...) )
2654 };
2655
2656 /**
2657 * hb_ot_layout_lookup_get_optical_bound:
2658 * @font: a font.
2659 * @lookup_index: index of the feature lookup to query.
2660 * @direction: edge of the glyph to query.
2661 * @glyph: a glyph id.
2662 *
2663 * Fetches the optical bound of a glyph positioned at the margin of text.
2664 * The direction identifies which edge of the glyph to query.
2665 *
2666 * Return value: Adjustment value. Negative values mean the glyph will stick out of the margin.
2667 *
2668 * Since: 5.3.0
2669 **/
2670 hb_position_t
hb_ot_layout_lookup_get_optical_bound(hb_font_t * font,unsigned lookup_index,hb_direction_t direction,hb_codepoint_t glyph)2671 hb_ot_layout_lookup_get_optical_bound (hb_font_t *font,
2672 unsigned lookup_index,
2673 hb_direction_t direction,
2674 hb_codepoint_t glyph)
2675 {
2676 const OT::PosLookup &lookup = font->face->table.GPOS->table->get_lookup (lookup_index);
2677 hb_blob_t *blob = font->face->table.GPOS->get_blob ();
2678 hb_glyph_position_t pos = {0};
2679 hb_position_single_dispatch_t c;
2680 lookup.dispatch (&c, font, blob, direction, glyph, pos);
2681 hb_position_t ret = 0;
2682 switch (direction)
2683 {
2684 case HB_DIRECTION_LTR:
2685 ret = pos.x_offset;
2686 break;
2687 case HB_DIRECTION_RTL:
2688 ret = pos.x_advance - pos.x_offset;
2689 break;
2690 case HB_DIRECTION_TTB:
2691 ret = pos.y_offset;
2692 break;
2693 case HB_DIRECTION_BTT:
2694 ret = pos.y_advance - pos.y_offset;
2695 break;
2696 case HB_DIRECTION_INVALID:
2697 default:
2698 break;
2699 }
2700 return ret;
2701 }
2702 #endif
2703
2704
2705 #endif
2706