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1 /*
2  * Copyright © 1998-2004  David Turner and Werner Lemberg
3  * Copyright © 2006  Behdad Esfahbod
4  * Copyright © 2007,2008,2009  Red Hat, Inc.
5  * Copyright © 2012,2013  Google, Inc.
6  *
7  *  This is part of HarfBuzz, a text shaping library.
8  *
9  * Permission is hereby granted, without written agreement and without
10  * license or royalty fees, to use, copy, modify, and distribute this
11  * software and its documentation for any purpose, provided that the
12  * above copyright notice and the following two paragraphs appear in
13  * all copies of this software.
14  *
15  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
16  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
17  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
18  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
19  * DAMAGE.
20  *
21  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
22  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
23  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
24  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
25  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
26  *
27  * Red Hat Author(s): Behdad Esfahbod
28  * Google Author(s): Behdad Esfahbod
29  */
30 
31 #include "hb-open-type.hh"
32 #include "hb-ot-layout.hh"
33 #include "hb-ot-face.hh"
34 #include "hb-ot-map.hh"
35 #include "hb-map.hh"
36 
37 #include "hb-ot-kern-table.hh"
38 #include "hb-ot-gasp-table.hh" // Just so we compile it; unused otherwise.
39 #include "hb-ot-layout-gdef-table.hh"
40 #include "hb-ot-layout-gsub-table.hh"
41 #include "hb-ot-layout-gpos-table.hh"
42 #include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise.
43 #include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
44 #include "hb-ot-name-table.hh"
45 #include "hb-ot-os2-table.hh"
46 
47 #include "hb-aat-layout-lcar-table.hh"
48 #include "hb-aat-layout-morx-table.hh"
49 
50 
51 /**
52  * SECTION:hb-ot-layout
53  * @title: hb-ot-layout
54  * @short_description: OpenType Layout
55  * @include: hb-ot.h
56  *
57  * Functions for querying OpenType Layout features in the font face.
58  **/
59 
60 
61 /*
62  * kern
63  */
64 
65 bool
hb_ot_layout_has_kerning(hb_face_t * face)66 hb_ot_layout_has_kerning (hb_face_t *face)
67 {
68   return face->table.kern->has_data ();
69 }
70 
71 bool
hb_ot_layout_has_machine_kerning(hb_face_t * face)72 hb_ot_layout_has_machine_kerning (hb_face_t *face)
73 {
74   return face->table.kern->has_state_machine ();
75 }
76 
77 bool
hb_ot_layout_has_cross_kerning(hb_face_t * face)78 hb_ot_layout_has_cross_kerning (hb_face_t *face)
79 {
80   return face->table.kern->has_cross_stream ();
81 }
82 
83 void
hb_ot_layout_kern(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer)84 hb_ot_layout_kern (const hb_ot_shape_plan_t *plan,
85 		   hb_font_t *font,
86 		   hb_buffer_t  *buffer)
87 {
88   hb_blob_t *blob = font->face->table.kern.get_blob ();
89   const AAT::kern& kern = *blob->as<AAT::kern> ();
90 
91   AAT::hb_aat_apply_context_t c (plan, font, buffer, blob);
92 
93   kern.apply (&c);
94 }
95 
96 
97 /*
98  * GDEF
99  */
100 
101 bool
is_blacklisted(hb_blob_t * blob,hb_face_t * face) const102 OT::GDEF::is_blacklisted (hb_blob_t *blob,
103 			  hb_face_t *face) const
104 {
105   /* The ugly business of blacklisting individual fonts' tables happen here!
106    * See this thread for why we finally had to bend in and do this:
107    * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
108    *
109    * In certain versions of Times New Roman Italic and Bold Italic,
110    * ASCII double quotation mark U+0022 has wrong glyph class 3 (mark)
111    * in GDEF.  Many versions of Tahoma have bad GDEF tables that
112    * incorrectly classify some spacing marks such as certain IPA
113    * symbols as glyph class 3. So do older versions of Microsoft
114    * Himalaya, and the version of Cantarell shipped by Ubuntu 16.04.
115    *
116    * Nuke the GDEF tables of to avoid unwanted width-zeroing.
117    *
118    * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925
119    *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279693
120    *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279875
121    */
122 #define ENCODE(x,y,z) (((uint64_t) (x) << 48) | ((uint64_t) (y) << 24) | (uint64_t) (z))
123   switch ENCODE(blob->length,
124 		face->table.GSUB->table.get_length (),
125 		face->table.GPOS->table.get_length ())
126   {
127     /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */
128     case ENCODE (442, 2874, 42038):
129     /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */
130     case ENCODE (430, 2874, 40662):
131     /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */
132     case ENCODE (442, 2874, 39116):
133     /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */
134     case ENCODE (430, 2874, 39374):
135     /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */
136     case ENCODE (490, 3046, 41638):
137     /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */
138     case ENCODE (478, 3046, 41902):
139     /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c  tahoma.ttf from Windows 8 */
140     case ENCODE (898, 12554, 46470):
141     /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc  tahomabd.ttf from Windows 8 */
142     case ENCODE (910, 12566, 47732):
143     /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e  tahoma.ttf from Windows 8.1 */
144     case ENCODE (928, 23298, 59332):
145     /* sha1sum:6d400781948517c3c0441ba42acb309584b73033  tahomabd.ttf from Windows 8.1 */
146     case ENCODE (940, 23310, 60732):
147     /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
148     case ENCODE (964, 23836, 60072):
149     /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
150     case ENCODE (976, 23832, 61456):
151     /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846  tahoma.ttf from Windows 10 */
152     case ENCODE (994, 24474, 60336):
153     /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343  tahomabd.ttf from Windows 10 */
154     case ENCODE (1006, 24470, 61740):
155     /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
156     case ENCODE (1006, 24576, 61346):
157     /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
158     case ENCODE (1018, 24572, 62828):
159     /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5  tahoma.ttf from Windows 10 AU */
160     case ENCODE (1006, 24576, 61352):
161     /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2  tahomabd.ttf from Windows 10 AU */
162     case ENCODE (1018, 24572, 62834):
163     /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7  Tahoma.ttf from Mac OS X 10.9 */
164     case ENCODE (832, 7324, 47162):
165     /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba  Tahoma Bold.ttf from Mac OS X 10.9 */
166     case ENCODE (844, 7302, 45474):
167     /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc  himalaya.ttf from Windows 7 */
168     case ENCODE (180, 13054, 7254):
169     /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0  himalaya.ttf from Windows 8 */
170     case ENCODE (192, 12638, 7254):
171     /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427  himalaya.ttf from Windows 8.1 */
172     case ENCODE (192, 12690, 7254):
173     /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44  cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */
174     /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371  cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */
175     case ENCODE (188, 248, 3852):
176     /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f  cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */
177     /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b  cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */
178     case ENCODE (188, 264, 3426):
179     /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */
180     case ENCODE (1058, 47032, 11818):
181     /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/
182     case ENCODE (1046, 47030, 12600):
183     /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */
184     case ENCODE (1058, 71796, 16770):
185     /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */
186     case ENCODE (1046, 71790, 17862):
187     /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */
188     case ENCODE (1046, 71788, 17112):
189     /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */
190     case ENCODE (1058, 71794, 17514):
191     /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */
192     case ENCODE (1330, 109904, 57938):
193     /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */
194     case ENCODE (1330, 109904, 58972):
195     /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85  Padauk.ttf
196      *  "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */
197     case ENCODE (1004, 59092, 14836):
198       return true;
199 #undef ENCODE
200   }
201   return false;
202 }
203 
204 static void
_hb_ot_layout_set_glyph_props(hb_font_t * font,hb_buffer_t * buffer)205 _hb_ot_layout_set_glyph_props (hb_font_t *font,
206 			       hb_buffer_t *buffer)
207 {
208   _hb_buffer_assert_gsubgpos_vars (buffer);
209 
210   const OT::GDEF &gdef = *font->face->table.GDEF->table;
211   unsigned int count = buffer->len;
212   for (unsigned int i = 0; i < count; i++)
213   {
214     _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
215     _hb_glyph_info_clear_lig_props (&buffer->info[i]);
216     buffer->info[i].syllable() = 0;
217   }
218 }
219 
220 /* Public API */
221 
222 hb_bool_t
hb_ot_layout_has_glyph_classes(hb_face_t * face)223 hb_ot_layout_has_glyph_classes (hb_face_t *face)
224 {
225   return face->table.GDEF->table->has_glyph_classes ();
226 }
227 
228 /**
229  * hb_ot_layout_get_glyph_class:
230  *
231  * Since: 0.9.7
232  **/
233 hb_ot_layout_glyph_class_t
hb_ot_layout_get_glyph_class(hb_face_t * face,hb_codepoint_t glyph)234 hb_ot_layout_get_glyph_class (hb_face_t      *face,
235 			      hb_codepoint_t  glyph)
236 {
237   return (hb_ot_layout_glyph_class_t) face->table.GDEF->table->get_glyph_class (glyph);
238 }
239 
240 /**
241  * hb_ot_layout_get_glyphs_in_class:
242  *
243  * Since: 0.9.7
244  **/
245 void
hb_ot_layout_get_glyphs_in_class(hb_face_t * face,hb_ot_layout_glyph_class_t klass,hb_set_t * glyphs)246 hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
247 				  hb_ot_layout_glyph_class_t  klass,
248 				  hb_set_t                   *glyphs /* OUT */)
249 {
250   return face->table.GDEF->table->get_glyphs_in_class (klass, glyphs);
251 }
252 
253 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)254 hb_ot_layout_get_attach_points (hb_face_t      *face,
255 				hb_codepoint_t  glyph,
256 				unsigned int    start_offset,
257 				unsigned int   *point_count /* IN/OUT */,
258 				unsigned int   *point_array /* OUT */)
259 {
260   return face->table.GDEF->table->get_attach_points (glyph,
261 						     start_offset,
262 						     point_count,
263 						     point_array);
264 }
265 
266 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)267 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
268 				  hb_direction_t  direction,
269 				  hb_codepoint_t  glyph,
270 				  unsigned int    start_offset,
271 				  unsigned int   *caret_count /* IN/OUT */,
272 				  hb_position_t  *caret_array /* OUT */)
273 {
274   unsigned int result_caret_count = 0;
275   unsigned int result = font->face->table.GDEF->table->get_lig_carets (font, direction, glyph, start_offset, &result_caret_count, caret_array);
276   if (result)
277   {
278     if (caret_count) *caret_count = result_caret_count;
279   }
280   else
281     result = font->face->table.lcar->get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
282   return result;
283 }
284 
285 
286 /*
287  * GSUB/GPOS
288  */
289 
290 bool
is_blacklisted(hb_blob_t * blob HB_UNUSED,hb_face_t * face) const291 OT::GSUB::is_blacklisted (hb_blob_t *blob HB_UNUSED,
292 			  hb_face_t *face) const
293 {
294   /* Mac OS X prefers morx over GSUB.  It also ships with various Indic fonts,
295    * all by 'MUTF' foundry (Tamil MN, Tamil Sangam MN, etc.), that have broken
296    * GSUB/GPOS tables.  Some have GSUB with zero scripts, those are ignored by
297    * our morx/GSUB preference code.  But if GSUB has non-zero scripts, we tend
298    * to prefer it over morx because we want to be consistent with other OpenType
299    * shapers.
300    *
301    * To work around broken Indic Mac system fonts, we ignore GSUB table if
302    * OS/2 VendorId is 'MUTF' and font has morx table as well.
303    *
304    * https://github.com/harfbuzz/harfbuzz/issues/1410
305    * https://github.com/harfbuzz/harfbuzz/issues/1348
306    * https://github.com/harfbuzz/harfbuzz/issues/1391
307    */
308   if (unlikely (face->table.OS2->achVendID == HB_TAG ('M','U','T','F') &&
309 		face->table.morx->has_data ()))
310     return true;
311 
312   return false;
313 }
314 
315 bool
is_blacklisted(hb_blob_t * blob HB_UNUSED,hb_face_t * face HB_UNUSED) const316 OT::GPOS::is_blacklisted (hb_blob_t *blob HB_UNUSED,
317 			  hb_face_t *face HB_UNUSED) const
318 {
319   return false;
320 }
321 
322 static const OT::GSUBGPOS&
get_gsubgpos_table(hb_face_t * face,hb_tag_t table_tag)323 get_gsubgpos_table (hb_face_t *face,
324 		    hb_tag_t   table_tag)
325 {
326   switch (table_tag) {
327     case HB_OT_TAG_GSUB: return *face->table.GSUB->table;
328     case HB_OT_TAG_GPOS: return *face->table.GPOS->table;
329     default:             return Null(OT::GSUBGPOS);
330   }
331 }
332 
333 
334 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)335 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
336 				    hb_tag_t      table_tag,
337 				    unsigned int  start_offset,
338 				    unsigned int *script_count /* IN/OUT */,
339 				    hb_tag_t     *script_tags  /* OUT */)
340 {
341   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
342 
343   return g.get_script_tags (start_offset, script_count, script_tags);
344 }
345 
346 #define HB_OT_TAG_LATIN_SCRIPT		HB_TAG ('l', 'a', 't', 'n')
347 
348 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)349 hb_ot_layout_table_find_script (hb_face_t    *face,
350 				hb_tag_t      table_tag,
351 				hb_tag_t      script_tag,
352 				unsigned int *script_index)
353 {
354   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
355   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
356 
357   if (g.find_script_index (script_tag, script_index))
358     return true;
359 
360   /* try finding 'DFLT' */
361   if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
362     return false;
363 
364   /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
365    * including many versions of DejaVu Sans Mono! */
366   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
367     return false;
368 
369   /* try with 'latn'; some old fonts put their features there even though
370      they're really trying to support Thai, for example :( */
371   if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index))
372     return false;
373 
374   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
375   return false;
376 }
377 
378 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)379 hb_ot_layout_table_choose_script (hb_face_t      *face,
380 				  hb_tag_t        table_tag,
381 				  const hb_tag_t *script_tags,
382 				  unsigned int   *script_index,
383 				  hb_tag_t       *chosen_script)
384 {
385   const hb_tag_t *t;
386   for (t = script_tags; *t; t++);
387   return hb_ot_layout_table_select_script (face, table_tag, t - script_tags, script_tags, script_index, chosen_script);
388 }
389 
390 /**
391  * hb_ot_layout_table_select_script:
392  *
393  * Since: 2.0.0
394  **/
395 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)396 hb_ot_layout_table_select_script (hb_face_t      *face,
397 				  hb_tag_t        table_tag,
398 				  unsigned int    script_count,
399 				  const hb_tag_t *script_tags,
400 				  unsigned int   *script_index  /* OUT */,
401 				  hb_tag_t       *chosen_script /* OUT */)
402 {
403   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
404   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
405   unsigned int i;
406 
407   for (i = 0; i < script_count; i++)
408   {
409     if (g.find_script_index (script_tags[i], script_index))
410     {
411       if (chosen_script)
412         *chosen_script = script_tags[i];
413       return true;
414     }
415   }
416 
417   /* try finding 'DFLT' */
418   if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
419     if (chosen_script)
420       *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
421     return false;
422   }
423 
424   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
425   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
426     if (chosen_script)
427       *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
428     return false;
429   }
430 
431   /* try with 'latn'; some old fonts put their features there even though
432      they're really trying to support Thai, for example :( */
433   if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
434     if (chosen_script)
435       *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
436     return false;
437   }
438 
439   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
440   if (chosen_script)
441     *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
442   return false;
443 }
444 
445 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)446 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
447 				     hb_tag_t      table_tag,
448 				     unsigned int  start_offset,
449 				     unsigned int *feature_count /* IN/OUT */,
450 				     hb_tag_t     *feature_tags  /* OUT */)
451 {
452   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
453 
454   return g.get_feature_tags (start_offset, feature_count, feature_tags);
455 }
456 
457 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)458 hb_ot_layout_table_find_feature (hb_face_t    *face,
459 				 hb_tag_t      table_tag,
460 				 hb_tag_t      feature_tag,
461 				 unsigned int *feature_index)
462 {
463   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
464   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
465 
466   unsigned int num_features = g.get_feature_count ();
467   for (unsigned int i = 0; i < num_features; i++)
468   {
469     if (feature_tag == g.get_feature_tag (i)) {
470       if (feature_index) *feature_index = i;
471       return true;
472     }
473   }
474 
475   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
476   return false;
477 }
478 
479 
480 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)481 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
482 				       hb_tag_t      table_tag,
483 				       unsigned int  script_index,
484 				       unsigned int  start_offset,
485 				       unsigned int *language_count /* IN/OUT */,
486 				       hb_tag_t     *language_tags  /* OUT */)
487 {
488   const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
489 
490   return s.get_lang_sys_tags (start_offset, language_count, language_tags);
491 }
492 
493 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)494 hb_ot_layout_script_find_language (hb_face_t    *face,
495 				   hb_tag_t      table_tag,
496 				   unsigned int  script_index,
497 				   hb_tag_t      language_tag,
498 				   unsigned int *language_index)
499 {
500   return hb_ot_layout_script_select_language (face,
501 					      table_tag,
502 					      script_index,
503 					      1,
504 					      &language_tag,
505 					      language_index);
506 }
507 
508 /**
509  * hb_ot_layout_script_select_language:
510  *
511  * Since: 2.0.0
512  **/
513 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)514 hb_ot_layout_script_select_language (hb_face_t      *face,
515 				     hb_tag_t        table_tag,
516 				     unsigned int    script_index,
517 				     unsigned int    language_count,
518 				     const hb_tag_t *language_tags,
519 				     unsigned int   *language_index /* OUT */)
520 {
521   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX), "");
522   const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
523   unsigned int i;
524 
525   for (i = 0; i < language_count; i++)
526   {
527     if (s.find_lang_sys_index (language_tags[i], language_index))
528       return true;
529   }
530 
531   /* try finding 'dflt' */
532   if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
533     return false;
534 
535   if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
536   return false;
537 }
538 
539 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)540 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
541 						  hb_tag_t      table_tag,
542 						  unsigned int  script_index,
543 						  unsigned int  language_index,
544 						  unsigned int *feature_index)
545 {
546   return hb_ot_layout_language_get_required_feature (face,
547 						     table_tag,
548 						     script_index,
549 						     language_index,
550 						     feature_index,
551 						     nullptr);
552 }
553 
554 /**
555  * hb_ot_layout_language_get_required_feature:
556  *
557  * Since: 0.9.30
558  **/
559 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)560 hb_ot_layout_language_get_required_feature (hb_face_t    *face,
561 					    hb_tag_t      table_tag,
562 					    unsigned int  script_index,
563 					    unsigned int  language_index,
564 					    unsigned int *feature_index,
565 					    hb_tag_t     *feature_tag)
566 {
567   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
568   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
569 
570   unsigned int index = l.get_required_feature_index ();
571   if (feature_index) *feature_index = index;
572   if (feature_tag) *feature_tag = g.get_feature_tag (index);
573 
574   return l.has_required_feature ();
575 }
576 
577 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)578 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
579 					   hb_tag_t      table_tag,
580 					   unsigned int  script_index,
581 					   unsigned int  language_index,
582 					   unsigned int  start_offset,
583 					   unsigned int *feature_count   /* IN/OUT */,
584 					   unsigned int *feature_indexes /* OUT */)
585 {
586   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
587   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
588 
589   return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
590 }
591 
592 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)593 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
594 					hb_tag_t      table_tag,
595 					unsigned int  script_index,
596 					unsigned int  language_index,
597 					unsigned int  start_offset,
598 					unsigned int *feature_count /* IN/OUT */,
599 					hb_tag_t     *feature_tags  /* OUT */)
600 {
601   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
602   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
603 
604   static_assert ((sizeof (unsigned int) == sizeof (hb_tag_t)), "");
605   unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
606 
607   if (feature_tags) {
608     unsigned int count = *feature_count;
609     for (unsigned int i = 0; i < count; i++)
610       feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
611   }
612 
613   return ret;
614 }
615 
616 
617 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)618 hb_ot_layout_language_find_feature (hb_face_t    *face,
619 				    hb_tag_t      table_tag,
620 				    unsigned int  script_index,
621 				    unsigned int  language_index,
622 				    hb_tag_t      feature_tag,
623 				    unsigned int *feature_index)
624 {
625   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
626   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
627   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
628 
629   unsigned int num_features = l.get_feature_count ();
630   for (unsigned int i = 0; i < num_features; i++) {
631     unsigned int f_index = l.get_feature_index (i);
632 
633     if (feature_tag == g.get_feature_tag (f_index)) {
634       if (feature_index) *feature_index = f_index;
635       return true;
636     }
637   }
638 
639   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
640   return false;
641 }
642 
643 /**
644  * hb_ot_layout_feature_get_lookups:
645  *
646  * Since: 0.9.7
647  **/
648 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)649 hb_ot_layout_feature_get_lookups (hb_face_t    *face,
650 				  hb_tag_t      table_tag,
651 				  unsigned int  feature_index,
652 				  unsigned int  start_offset,
653 				  unsigned int *lookup_count   /* IN/OUT */,
654 				  unsigned int *lookup_indexes /* OUT */)
655 {
656   return hb_ot_layout_feature_with_variations_get_lookups (face,
657 							   table_tag,
658 							   feature_index,
659 							   HB_OT_LAYOUT_NO_VARIATIONS_INDEX,
660 							   start_offset,
661 							   lookup_count,
662 							   lookup_indexes);
663 }
664 
665 /**
666  * hb_ot_layout_table_get_lookup_count:
667  *
668  * Since: 0.9.22
669  **/
670 unsigned int
hb_ot_layout_table_get_lookup_count(hb_face_t * face,hb_tag_t table_tag)671 hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
672 				     hb_tag_t      table_tag)
673 {
674   return get_gsubgpos_table (face, table_tag).get_lookup_count ();
675 }
676 
677 
678 struct hb_collect_features_context_t
679 {
hb_collect_features_context_thb_collect_features_context_t680   hb_collect_features_context_t (hb_face_t       *face,
681 				 hb_tag_t         table_tag,
682 				 hb_set_t        *feature_indexes_)
683     : g (get_gsubgpos_table (face, table_tag)),
684       feature_indexes (feature_indexes_),
685       script_count(0),langsys_count(0) {}
686 
visitedhb_collect_features_context_t687   bool inline visited (const OT::Script &s)
688   {
689     /* We might have Null() object here.  Don't want to involve
690      * that in the memoize.  So, detect empty objects and return. */
691     if (unlikely (!s.has_default_lang_sys () &&
692 		  !s.get_lang_sys_count ()))
693       return true;
694 
695     if (script_count++ > HB_MAX_SCRIPTS)
696       return true;
697 
698     return visited (s, visited_script);
699   }
visitedhb_collect_features_context_t700   bool inline visited (const OT::LangSys &l)
701   {
702     /* We might have Null() object here.  Don't want to involve
703      * that in the memoize.  So, detect empty objects and return. */
704     if (unlikely (!l.has_required_feature () &&
705 		  !l.get_feature_count ()))
706       return true;
707 
708     if (langsys_count++ > HB_MAX_LANGSYS)
709       return true;
710 
711     return visited (l, visited_langsys);
712   }
713 
714   private:
715   template <typename T>
visitedhb_collect_features_context_t716   bool inline visited (const T &p, hb_set_t &visited_set)
717   {
718     hb_codepoint_t delta = (hb_codepoint_t) ((uintptr_t) &p - (uintptr_t) &g);
719      if (visited_set.has (delta))
720       return true;
721 
722     visited_set.add (delta);
723     return false;
724   }
725 
726   public:
727   const OT::GSUBGPOS &g;
728   hb_set_t           *feature_indexes;
729 
730   private:
731   hb_set_t visited_script;
732   hb_set_t visited_langsys;
733   unsigned int script_count;
734   unsigned int langsys_count;
735 };
736 
737 static void
langsys_collect_features(hb_collect_features_context_t * c,const OT::LangSys & l,const hb_tag_t * features)738 langsys_collect_features (hb_collect_features_context_t *c,
739 			  const OT::LangSys  &l,
740 			  const hb_tag_t     *features)
741 {
742   if (c->visited (l)) return;
743 
744   if (!features)
745   {
746     /* All features. */
747     if (l.has_required_feature ())
748       c->feature_indexes->add (l.get_required_feature_index ());
749 
750     l.add_feature_indexes_to (c->feature_indexes);
751   }
752   else
753   {
754     /* Ugh. Any faster way? */
755     for (; *features; features++)
756     {
757       hb_tag_t feature_tag = *features;
758       unsigned int num_features = l.get_feature_count ();
759       for (unsigned int i = 0; i < num_features; i++)
760       {
761 	unsigned int feature_index = l.get_feature_index (i);
762 
763 	if (feature_tag == c->g.get_feature_tag (feature_index))
764 	{
765 	  c->feature_indexes->add (feature_index);
766 	  break;
767 	}
768       }
769     }
770   }
771 }
772 
773 static void
script_collect_features(hb_collect_features_context_t * c,const OT::Script & s,const hb_tag_t * languages,const hb_tag_t * features)774 script_collect_features (hb_collect_features_context_t *c,
775 			 const OT::Script   &s,
776 			 const hb_tag_t *languages,
777 			 const hb_tag_t *features)
778 {
779   if (c->visited (s)) return;
780 
781   if (!languages)
782   {
783     /* All languages. */
784     if (s.has_default_lang_sys ())
785       langsys_collect_features (c,
786 				s.get_default_lang_sys (),
787 				features);
788 
789     unsigned int count = s.get_lang_sys_count ();
790     for (unsigned int language_index = 0; language_index < count; language_index++)
791       langsys_collect_features (c,
792 				s.get_lang_sys (language_index),
793 				features);
794   }
795   else
796   {
797     for (; *languages; languages++)
798     {
799       unsigned int language_index;
800       if (s.find_lang_sys_index (*languages, &language_index))
801 	langsys_collect_features (c,
802 				  s.get_lang_sys (language_index),
803 				  features);
804     }
805   }
806 }
807 
808 /**
809  * hb_ot_layout_collect_features:
810  *
811  * Since: 1.8.5
812  **/
813 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)814 hb_ot_layout_collect_features (hb_face_t      *face,
815                                hb_tag_t        table_tag,
816                                const hb_tag_t *scripts,
817                                const hb_tag_t *languages,
818                                const hb_tag_t *features,
819                                hb_set_t       *feature_indexes /* OUT */)
820 {
821   hb_collect_features_context_t c (face, table_tag, feature_indexes);
822   if (!scripts)
823   {
824     /* All scripts. */
825     unsigned int count = c.g.get_script_count ();
826     for (unsigned int script_index = 0; script_index < count; script_index++)
827       script_collect_features (&c,
828 			       c.g.get_script (script_index),
829 			       languages,
830 			       features);
831   }
832   else
833   {
834     for (; *scripts; scripts++)
835     {
836       unsigned int script_index;
837       if (c.g.find_script_index (*scripts, &script_index))
838 	script_collect_features (&c,
839 				 c.g.get_script (script_index),
840 				 languages,
841 				 features);
842     }
843   }
844 }
845 
846 /**
847  * hb_ot_layout_collect_lookups:
848  *
849  * Since: 0.9.8
850  **/
851 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)852 hb_ot_layout_collect_lookups (hb_face_t      *face,
853 			      hb_tag_t        table_tag,
854 			      const hb_tag_t *scripts,
855 			      const hb_tag_t *languages,
856 			      const hb_tag_t *features,
857 			      hb_set_t       *lookup_indexes /* OUT */)
858 {
859   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
860 
861   hb_set_t feature_indexes;
862   hb_ot_layout_collect_features (face, table_tag, scripts, languages, features, &feature_indexes);
863 
864   for (hb_codepoint_t feature_index = HB_SET_VALUE_INVALID;
865        hb_set_next (&feature_indexes, &feature_index);)
866     g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes);
867 }
868 
869 /**
870  * hb_ot_layout_lookup_collect_glyphs:
871  *
872  * Since: 0.9.7
873  **/
874 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)875 hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
876 				    hb_tag_t      table_tag,
877 				    unsigned int  lookup_index,
878 				    hb_set_t     *glyphs_before, /* OUT.  May be NULL */
879 				    hb_set_t     *glyphs_input,  /* OUT.  May be NULL */
880 				    hb_set_t     *glyphs_after,  /* OUT.  May be NULL */
881 				    hb_set_t     *glyphs_output  /* OUT.  May be NULL */)
882 {
883   OT::hb_collect_glyphs_context_t c (face,
884 				     glyphs_before,
885 				     glyphs_input,
886 				     glyphs_after,
887 				     glyphs_output);
888 
889   switch (table_tag)
890   {
891     case HB_OT_TAG_GSUB:
892     {
893       const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
894       l.collect_glyphs (&c);
895       return;
896     }
897     case HB_OT_TAG_GPOS:
898     {
899       const OT::PosLookup& l = face->table.GPOS->table->get_lookup (lookup_index);
900       l.collect_glyphs (&c);
901       return;
902     }
903   }
904 }
905 
906 
907 /* Variations support */
908 
909 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)910 hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
911 					    hb_tag_t      table_tag,
912 					    const int    *coords,
913 					    unsigned int  num_coords,
914 					    unsigned int *variations_index /* out */)
915 {
916   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
917 
918   return g.find_variations_index (coords, num_coords, variations_index);
919 }
920 
921 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)922 hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
923 						  hb_tag_t      table_tag,
924 						  unsigned int  feature_index,
925 						  unsigned int  variations_index,
926 						  unsigned int  start_offset,
927 						  unsigned int *lookup_count /* IN/OUT */,
928 						  unsigned int *lookup_indexes /* OUT */)
929 {
930   static_assert ((OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX), "");
931   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
932 
933   const OT::Feature &f = g.get_feature_variation (feature_index, variations_index);
934 
935   return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
936 }
937 
938 
939 /*
940  * OT::GSUB
941  */
942 
943 hb_bool_t
hb_ot_layout_has_substitution(hb_face_t * face)944 hb_ot_layout_has_substitution (hb_face_t *face)
945 {
946   return face->table.GSUB->table->has_data ();
947 }
948 
949 /**
950  * hb_ot_layout_lookup_would_substitute:
951  *
952  * Since: 0.9.7
953  **/
954 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)955 hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
956 				      unsigned int          lookup_index,
957 				      const hb_codepoint_t *glyphs,
958 				      unsigned int          glyphs_length,
959 				      hb_bool_t             zero_context)
960 {
961   return hb_ot_layout_lookup_would_substitute_fast (face,
962 						    lookup_index,
963 						    glyphs, glyphs_length,
964 						    zero_context);
965 }
966 
967 bool
hb_ot_layout_lookup_would_substitute_fast(hb_face_t * face,unsigned int lookup_index,const hb_codepoint_t * glyphs,unsigned int glyphs_length,bool zero_context)968 hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
969 					   unsigned int          lookup_index,
970 					   const hb_codepoint_t *glyphs,
971 					   unsigned int          glyphs_length,
972 					   bool                  zero_context)
973 {
974   if (unlikely (lookup_index >= face->table.GSUB->lookup_count)) return false;
975   OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
976 
977   const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
978 
979   return l.would_apply (&c, &face->table.GSUB->accels[lookup_index]);
980 }
981 
982 void
hb_ot_layout_substitute_start(hb_font_t * font,hb_buffer_t * buffer)983 hb_ot_layout_substitute_start (hb_font_t    *font,
984 			       hb_buffer_t  *buffer)
985 {
986 _hb_ot_layout_set_glyph_props (font, buffer);
987 }
988 
989 void
hb_ot_layout_delete_glyphs_inplace(hb_buffer_t * buffer,bool (* filter)(const hb_glyph_info_t * info))990 hb_ot_layout_delete_glyphs_inplace (hb_buffer_t *buffer,
991 				    bool (*filter) (const hb_glyph_info_t *info))
992 {
993   /* Merge clusters and delete filtered glyphs.
994    * NOTE! We can't use out-buffer as we have positioning data. */
995   unsigned int j = 0;
996   unsigned int count = buffer->len;
997   hb_glyph_info_t *info = buffer->info;
998   hb_glyph_position_t *pos = buffer->pos;
999   for (unsigned int i = 0; i < count; i++)
1000   {
1001     if (filter (&info[i]))
1002     {
1003       /* Merge clusters.
1004        * Same logic as buffer->delete_glyph(), but for in-place removal. */
1005 
1006       unsigned int cluster = info[i].cluster;
1007       if (i + 1 < count && cluster == info[i + 1].cluster)
1008 	continue; /* Cluster survives; do nothing. */
1009 
1010       if (j)
1011       {
1012 	/* Merge cluster backward. */
1013 	if (cluster < info[j - 1].cluster)
1014 	{
1015 	  unsigned int mask = info[i].mask;
1016 	  unsigned int old_cluster = info[j - 1].cluster;
1017 	  for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
1018 	    buffer->set_cluster (info[k - 1], cluster, mask);
1019 	}
1020 	continue;
1021       }
1022 
1023       if (i + 1 < count)
1024 	buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */
1025 
1026       continue;
1027     }
1028 
1029     if (j != i)
1030     {
1031       info[j] = info[i];
1032       pos[j] = pos[i];
1033     }
1034     j++;
1035   }
1036   buffer->len = j;
1037 }
1038 
1039 /**
1040  * hb_ot_layout_lookup_substitute_closure:
1041  *
1042  * Since: 0.9.7
1043  **/
1044 void
hb_ot_layout_lookup_substitute_closure(hb_face_t * face,unsigned int lookup_index,hb_set_t * glyphs)1045 hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
1046 				        unsigned int  lookup_index,
1047 				        hb_set_t     *glyphs)
1048 {
1049   hb_map_t done_lookups;
1050   OT::hb_closure_context_t c (face, glyphs, &done_lookups);
1051 
1052   const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
1053 
1054   l.closure (&c, lookup_index);
1055 }
1056 
1057 /**
1058  * hb_ot_layout_lookups_substitute_closure:
1059  *
1060  * Compute the transitive closure of glyphs needed for all of the
1061  * provided lookups.
1062  *
1063  * Since: 1.8.1
1064  **/
1065 void
hb_ot_layout_lookups_substitute_closure(hb_face_t * face,const hb_set_t * lookups,hb_set_t * glyphs)1066 hb_ot_layout_lookups_substitute_closure (hb_face_t      *face,
1067                                          const hb_set_t *lookups,
1068                                          hb_set_t       *glyphs)
1069 {
1070   hb_map_t done_lookups;
1071   OT::hb_closure_context_t c (face, glyphs, &done_lookups);
1072   const OT::GSUB& gsub = *face->table.GSUB->table;
1073 
1074   unsigned int iteration_count = 0;
1075   unsigned int glyphs_length;
1076   do
1077   {
1078     glyphs_length = glyphs->get_population ();
1079     if (lookups != nullptr)
1080     {
1081       for (hb_codepoint_t lookup_index = HB_SET_VALUE_INVALID; hb_set_next (lookups, &lookup_index);)
1082         gsub.get_lookup (lookup_index).closure (&c, lookup_index);
1083     }
1084     else
1085     {
1086       for (unsigned int i = 0; i < gsub.get_lookup_count (); i++)
1087         gsub.get_lookup (i).closure (&c, i);
1088     }
1089   } while (iteration_count++ <= HB_CLOSURE_MAX_STAGES &&
1090 	   glyphs_length != glyphs->get_population ());
1091 }
1092 
1093 /*
1094  * OT::GPOS
1095  */
1096 
1097 hb_bool_t
hb_ot_layout_has_positioning(hb_face_t * face)1098 hb_ot_layout_has_positioning (hb_face_t *face)
1099 {
1100   return face->table.GPOS->table->has_data ();
1101 }
1102 
1103 void
hb_ot_layout_position_start(hb_font_t * font,hb_buffer_t * buffer)1104 hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
1105 {
1106   OT::GPOS::position_start (font, buffer);
1107 }
1108 
1109 void
hb_ot_layout_position_finish_advances(hb_font_t * font,hb_buffer_t * buffer)1110 hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
1111 {
1112   OT::GPOS::position_finish_advances (font, buffer);
1113 }
1114 
1115 void
hb_ot_layout_position_finish_offsets(hb_font_t * font,hb_buffer_t * buffer)1116 hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
1117 {
1118   OT::GPOS::position_finish_offsets (font, buffer);
1119 }
1120 
1121 /**
1122  * hb_ot_layout_get_size_params:
1123  *
1124  * Since: 0.9.10
1125  **/
1126 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)1127 hb_ot_layout_get_size_params (hb_face_t       *face,
1128 			      unsigned int    *design_size,       /* OUT.  May be NULL */
1129 			      unsigned int    *subfamily_id,      /* OUT.  May be NULL */
1130 			      hb_ot_name_id_t *subfamily_name_id, /* OUT.  May be NULL */
1131 			      unsigned int    *range_start,       /* OUT.  May be NULL */
1132 			      unsigned int    *range_end          /* OUT.  May be NULL */)
1133 {
1134   const OT::GPOS &gpos = *face->table.GPOS->table;
1135   const hb_tag_t tag = HB_TAG ('s','i','z','e');
1136 
1137   unsigned int num_features = gpos.get_feature_count ();
1138   for (unsigned int i = 0; i < num_features; i++)
1139   {
1140     if (tag == gpos.get_feature_tag (i))
1141     {
1142       const OT::Feature &f = gpos.get_feature (i);
1143       const OT::FeatureParamsSize &params = f.get_feature_params ().get_size_params (tag);
1144 
1145       if (params.designSize)
1146       {
1147 	if (design_size) *design_size = params.designSize;
1148 	if (subfamily_id) *subfamily_id = params.subfamilyID;
1149 	if (subfamily_name_id) *subfamily_name_id = params.subfamilyNameID;
1150 	if (range_start) *range_start = params.rangeStart;
1151 	if (range_end) *range_end = params.rangeEnd;
1152 
1153 	return true;
1154       }
1155     }
1156   }
1157 
1158   if (design_size) *design_size = 0;
1159   if (subfamily_id) *subfamily_id = 0;
1160   if (subfamily_name_id) *subfamily_name_id = HB_OT_NAME_ID_INVALID;
1161   if (range_start) *range_start = 0;
1162   if (range_end) *range_end = 0;
1163 
1164   return false;
1165 }
1166 
1167 /**
1168  * hb_ot_layout_feature_get_name_ids:
1169  * @face: #hb_face_t to work upon
1170  * @table_tag: table tag to query, "GSUB" or "GPOS".
1171  * @feature_index: index of feature to query.
1172  * @label_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
1173  *            for a user-interface label for this feature. (May be NULL.)
1174  * @tooltip_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
1175  *              that an application can use for tooltip text for this
1176  *              feature. (May be NULL.)
1177  * @sample_id: (out) (allow-none): The ‘name’ table name ID that specifies sample text
1178  *             that illustrates the effect of this feature. (May be NULL.)
1179  * @num_named_parameters: (out) (allow-none):  Number of named parameters. (May be zero.)
1180  * @first_param_id: (out) (allow-none): The first ‘name’ table name ID used to specify
1181  *                  strings for user-interface labels for the feature
1182  *                  parameters. (Must be zero if numParameters is zero.)
1183  *
1184  * Fetches name indices from feature parameters for "Stylistic Set" ('ssXX') or
1185  * "Character Variant" ('cvXX') features.
1186  *
1187  * Return value: true if data found, false otherwise
1188  *
1189  * Since: 2.0.0
1190  **/
1191 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)1192 hb_ot_layout_feature_get_name_ids (hb_face_t       *face,
1193 				   hb_tag_t         table_tag,
1194 				   unsigned int     feature_index,
1195 				   hb_ot_name_id_t *label_id,             /* OUT.  May be NULL */
1196 				   hb_ot_name_id_t *tooltip_id,           /* OUT.  May be NULL */
1197 				   hb_ot_name_id_t *sample_id,            /* OUT.  May be NULL */
1198 				   unsigned int    *num_named_parameters, /* OUT.  May be NULL */
1199 				   hb_ot_name_id_t *first_param_id        /* OUT.  May be NULL */)
1200 {
1201   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1202 
1203   hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1204   const OT::Feature &f = g.get_feature (feature_index);
1205 
1206   const OT::FeatureParams &feature_params = f.get_feature_params ();
1207   if (&feature_params != &Null (OT::FeatureParams))
1208   {
1209     const OT::FeatureParamsStylisticSet& ss_params =
1210       feature_params.get_stylistic_set_params (feature_tag);
1211     if (&ss_params != &Null (OT::FeatureParamsStylisticSet)) /* ssXX */
1212     {
1213       if (label_id) *label_id = ss_params.uiNameID;
1214       // ssXX features don't have the rest
1215       if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1216       if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1217       if (num_named_parameters) *num_named_parameters = 0;
1218       if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1219       return true;
1220     }
1221     const OT::FeatureParamsCharacterVariants& cv_params =
1222       feature_params.get_character_variants_params (feature_tag);
1223     if (&cv_params != &Null (OT::FeatureParamsCharacterVariants)) /* cvXX */
1224     {
1225       if (label_id) *label_id = cv_params.featUILableNameID;
1226       if (tooltip_id) *tooltip_id = cv_params.featUITooltipTextNameID;
1227       if (sample_id) *sample_id = cv_params.sampleTextNameID;
1228       if (num_named_parameters) *num_named_parameters = cv_params.numNamedParameters;
1229       if (first_param_id) *first_param_id = cv_params.firstParamUILabelNameID;
1230       return true;
1231     }
1232   }
1233 
1234   if (label_id) *label_id = HB_OT_NAME_ID_INVALID;
1235   if (tooltip_id) *tooltip_id = HB_OT_NAME_ID_INVALID;
1236   if (sample_id) *sample_id = HB_OT_NAME_ID_INVALID;
1237   if (num_named_parameters) *num_named_parameters = 0;
1238   if (first_param_id) *first_param_id = HB_OT_NAME_ID_INVALID;
1239   return false;
1240 }
1241 
1242 /**
1243  * hb_ot_layout_feature_get_characters:
1244  * @face: #hb_face_t to work upon
1245  * @table_tag: table tag to query, "GSUB" or "GPOS".
1246  * @feature_index: index of feature to query.
1247  * @start_offset: In case the resulting char_count was equal to its input value, there
1248  *                is a chance there were more characters on the tag so this API can be
1249  *                called with an offset till resulting char_count gets to a number
1250  *                lower than input buffer (or consider using just a bigger buffer for
1251  *                one shot copying).
1252  * @char_count: (inout) (allow-none): The count of characters for which this feature
1253  *              provides glyph variants. (May be zero.)
1254  * @characters: (out caller-allocates) (array length=char_count): A buffer pointer. The Unicode codepoints
1255  *              of the characters for which this feature provides glyph variants.
1256  *
1257  * Fetches characters listed by designer under feature parameters for "Character
1258  * Variant" ("cvXX") features.
1259  *
1260  * Return value: Number of total sample characters in the cvXX feature.
1261  *
1262  * Since: 2.0.0
1263  **/
1264 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)1265 hb_ot_layout_feature_get_characters (hb_face_t      *face,
1266 				     hb_tag_t        table_tag,
1267 				     unsigned int    feature_index,
1268 				     unsigned int    start_offset,
1269 				     unsigned int   *char_count, /* IN/OUT.  May be NULL */
1270 				     hb_codepoint_t *characters  /* OUT.     May be NULL */)
1271 {
1272   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
1273 
1274   hb_tag_t feature_tag = g.get_feature_tag (feature_index);
1275   const OT::Feature &f = g.get_feature (feature_index);
1276 
1277   const OT::FeatureParams &feature_params = f.get_feature_params ();
1278 
1279   const OT::FeatureParamsCharacterVariants& cv_params =
1280     feature_params.get_character_variants_params(feature_tag);
1281 
1282   unsigned int len = 0;
1283   if (char_count && characters && start_offset < cv_params.characters.len)
1284   {
1285     len = MIN (cv_params.characters.len - start_offset, *char_count);
1286     for (unsigned int i = 0; i < len; ++i)
1287       characters[i] = cv_params.characters[start_offset + i];
1288   }
1289   if (char_count) *char_count = len;
1290   return cv_params.characters.len;
1291 }
1292 
1293 
1294 /*
1295  * Parts of different types are implemented here such that they have direct
1296  * access to GSUB/GPOS lookups.
1297  */
1298 
1299 
1300 struct GSUBProxy
1301 {
1302   enum { table_index = 0 };
1303   enum { inplace = false };
1304   typedef OT::SubstLookup Lookup;
1305 
GSUBProxyGSUBProxy1306   GSUBProxy (hb_face_t *face) :
1307     table (*face->table.GSUB->table),
1308     accels (face->table.GSUB->accels) {}
1309 
1310   const OT::GSUB &table;
1311   const OT::hb_ot_layout_lookup_accelerator_t *accels;
1312 };
1313 
1314 struct GPOSProxy
1315 {
1316   enum { table_index = 1 };
1317   enum { inplace = true };
1318   typedef OT::PosLookup Lookup;
1319 
GPOSProxyGPOSProxy1320   GPOSProxy (hb_face_t *face) :
1321     table (*face->table.GPOS->table),
1322     accels (face->table.GPOS->accels) {}
1323 
1324   const OT::GPOS &table;
1325   const OT::hb_ot_layout_lookup_accelerator_t *accels;
1326 };
1327 
1328 
1329 static inline bool
apply_forward(OT::hb_ot_apply_context_t * c,const OT::hb_ot_layout_lookup_accelerator_t & accel)1330 apply_forward (OT::hb_ot_apply_context_t *c,
1331 	       const OT::hb_ot_layout_lookup_accelerator_t &accel)
1332 {
1333   bool ret = false;
1334   hb_buffer_t *buffer = c->buffer;
1335   while (buffer->idx < buffer->len && buffer->successful)
1336   {
1337     bool applied = false;
1338     if (accel.may_have (buffer->cur().codepoint) &&
1339 	(buffer->cur().mask & c->lookup_mask) &&
1340 	c->check_glyph_property (&buffer->cur(), c->lookup_props))
1341      {
1342        applied = accel.apply (c);
1343      }
1344 
1345     if (applied)
1346       ret = true;
1347     else
1348       buffer->next_glyph ();
1349   }
1350   return ret;
1351 }
1352 
1353 static inline bool
apply_backward(OT::hb_ot_apply_context_t * c,const OT::hb_ot_layout_lookup_accelerator_t & accel)1354 apply_backward (OT::hb_ot_apply_context_t *c,
1355 	       const OT::hb_ot_layout_lookup_accelerator_t &accel)
1356 {
1357   bool ret = false;
1358   hb_buffer_t *buffer = c->buffer;
1359   do
1360   {
1361     if (accel.may_have (buffer->cur().codepoint) &&
1362 	(buffer->cur().mask & c->lookup_mask) &&
1363 	c->check_glyph_property (&buffer->cur(), c->lookup_props))
1364      ret |= accel.apply (c);
1365 
1366     /* The reverse lookup doesn't "advance" cursor (for good reason). */
1367     buffer->idx--;
1368 
1369   }
1370   while ((int) buffer->idx >= 0);
1371   return ret;
1372 }
1373 
1374 template <typename Proxy>
1375 static inline void
apply_string(OT::hb_ot_apply_context_t * c,const typename Proxy::Lookup & lookup,const OT::hb_ot_layout_lookup_accelerator_t & accel)1376 apply_string (OT::hb_ot_apply_context_t *c,
1377 	      const typename Proxy::Lookup &lookup,
1378 	      const OT::hb_ot_layout_lookup_accelerator_t &accel)
1379 {
1380   hb_buffer_t *buffer = c->buffer;
1381 
1382   if (unlikely (!buffer->len || !c->lookup_mask))
1383     return;
1384 
1385   c->set_lookup_props (lookup.get_props ());
1386 
1387   if (likely (!lookup.is_reverse ()))
1388   {
1389     /* in/out forward substitution/positioning */
1390     if (Proxy::table_index == 0)
1391       buffer->clear_output ();
1392     buffer->idx = 0;
1393 
1394     bool ret;
1395     ret = apply_forward (c, accel);
1396     if (ret)
1397     {
1398       if (!Proxy::inplace)
1399 	buffer->swap_buffers ();
1400       else
1401 	assert (!buffer->has_separate_output ());
1402     }
1403   }
1404   else
1405   {
1406     /* in-place backward substitution/positioning */
1407     if (Proxy::table_index == 0)
1408       buffer->remove_output ();
1409     buffer->idx = buffer->len - 1;
1410 
1411     apply_backward (c, accel);
1412   }
1413 }
1414 
1415 template <typename Proxy>
apply(const Proxy & proxy,const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const1416 inline void hb_ot_map_t::apply (const Proxy &proxy,
1417 				const hb_ot_shape_plan_t *plan,
1418 				hb_font_t *font,
1419 				hb_buffer_t *buffer) const
1420 {
1421   const unsigned int table_index = proxy.table_index;
1422   unsigned int i = 0;
1423   OT::hb_ot_apply_context_t c (table_index, font, buffer);
1424   c.set_recurse_func (Proxy::Lookup::apply_recurse_func);
1425 
1426   for (unsigned int stage_index = 0; stage_index < stages[table_index].len; stage_index++) {
1427     const stage_map_t *stage = &stages[table_index][stage_index];
1428     for (; i < stage->last_lookup; i++)
1429     {
1430       unsigned int lookup_index = lookups[table_index][i].index;
1431       if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
1432       c.set_lookup_index (lookup_index);
1433       c.set_lookup_mask (lookups[table_index][i].mask);
1434       c.set_auto_zwj (lookups[table_index][i].auto_zwj);
1435       c.set_auto_zwnj (lookups[table_index][i].auto_zwnj);
1436       if (lookups[table_index][i].random)
1437       {
1438 	c.set_random (true);
1439 	buffer->unsafe_to_break_all ();
1440       }
1441       apply_string<Proxy> (&c,
1442 			   proxy.table.get_lookup (lookup_index),
1443 			   proxy.accels[lookup_index]);
1444       (void) buffer->message (font, "end lookup %d", lookup_index);
1445     }
1446 
1447     if (stage->pause_func)
1448     {
1449       buffer->clear_output ();
1450       stage->pause_func (plan, font, buffer);
1451     }
1452   }
1453 }
1454 
substitute(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const1455 void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1456 {
1457   GSUBProxy proxy (font->face);
1458   apply (proxy, plan, font, buffer);
1459 }
1460 
position(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const1461 void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1462 {
1463   GPOSProxy proxy (font->face);
1464   apply (proxy, plan, font, buffer);
1465 }
1466 
1467 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)1468 hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
1469 				const OT::SubstLookup &lookup,
1470 				const OT::hb_ot_layout_lookup_accelerator_t &accel)
1471 {
1472   apply_string<GSUBProxy> (c, lookup, accel);
1473 }
1474 
1475 #if 0
1476 static const OT::BASE& _get_base (hb_face_t *face)
1477 {
1478   return *face->table.BASE;
1479 }
1480 
1481 hb_bool_t
1482 hb_ot_layout_get_baseline (hb_font_t               *font,
1483 			   hb_ot_layout_baseline_t  baseline,
1484 			   hb_direction_t           direction,
1485 			   hb_tag_t                 script_tag,
1486 			   hb_tag_t                 language_tag,
1487 			   hb_position_t           *coord        /* OUT.  May be NULL. */)
1488 {
1489   const OT::BASE &base = _get_base (font->face);
1490   bool result = base.get_baseline (font, baseline, direction, script_tag,
1491 				   language_tag, coord);
1492 
1493   /* TODO: Simulate https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags#ideographic-em-box */
1494   if (!result && coord) *coord = 0;
1495 
1496   if (coord) *coord = font->em_scale_dir (*coord, direction);
1497 
1498   return result;
1499 }
1500 
1501 /* To be moved to public header */
1502 /*
1503  * BASE
1504  */
1505 
1506 /**
1507  * hb_ot_layout_baseline_t:
1508  *
1509  * https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags
1510  *
1511  * Since: DONTREPLACEME
1512  */
1513 typedef enum {
1514   HB_OT_LAYOUT_BASELINE_HANG = HB_TAG('h','a','n','g'),
1515   HB_OT_LAYOUT_BASELINE_ICFB = HB_TAG('i','c','f','b'),
1516   HB_OT_LAYOUT_BASELINE_ICFT = HB_TAG('i','c','f','t'),
1517   HB_OT_LAYOUT_BASELINE_IDEO = HB_TAG('i','d','e','o'),
1518   HB_OT_LAYOUT_BASELINE_IDTB = HB_TAG('i','d','t','b'),
1519   HB_OT_LAYOUT_BASELINE_MATH = HB_TAG('m','a','t','h'),
1520   HB_OT_LAYOUT_BASELINE_ROMN = HB_TAG('r','o','m','n')
1521 } hb_ot_layout_baseline_t;
1522 
1523 HB_EXTERN hb_bool_t
1524 hb_ot_layout_get_baseline (hb_font_t               *font,
1525 			   hb_ot_layout_baseline_t  baseline,
1526 			   hb_direction_t           direction,
1527 			   hb_tag_t                 script_tag,
1528 			   hb_tag_t                 language_tag,
1529 			   hb_position_t           *coord        /* OUT.  May be NULL. */);
1530 
1531 #endif
1532