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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-private.hh"
32 #include "hb-ot-layout-private.hh"
33 
34 #include "hb-ot-layout-gdef-table.hh"
35 #include "hb-ot-layout-gsub-table.hh"
36 #include "hb-ot-layout-gpos-table.hh"
37 #include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
38 #include "hb-ot-name-table.hh" // Just so we compile it; unused otherwise.
39 
40 #include "hb-ot-map-private.hh"
41 
42 
43 const void * const OT::_hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)] = {};
44 
45 
46 hb_ot_layout_t *
_hb_ot_layout_create(hb_face_t * face)47 _hb_ot_layout_create (hb_face_t *face)
48 {
49   hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
50   if (unlikely (!layout))
51     return nullptr;
52 
53   layout->gdef_blob = OT::Sanitizer<OT::GDEF>::sanitize (face->reference_table (HB_OT_TAG_GDEF));
54   layout->gdef = OT::Sanitizer<OT::GDEF>::lock_instance (layout->gdef_blob);
55 
56   layout->gsub_blob = OT::Sanitizer<OT::GSUB>::sanitize (face->reference_table (HB_OT_TAG_GSUB));
57   layout->gsub = OT::Sanitizer<OT::GSUB>::lock_instance (layout->gsub_blob);
58 
59   layout->gpos_blob = OT::Sanitizer<OT::GPOS>::sanitize (face->reference_table (HB_OT_TAG_GPOS));
60   layout->gpos = OT::Sanitizer<OT::GPOS>::lock_instance (layout->gpos_blob);
61 
62   layout->math.init (face);
63   layout->fvar.init (face);
64   layout->avar.init (face);
65 
66   {
67     /*
68      * The ugly business of blacklisting individual fonts' tables happen here!
69      * See this thread for why we finally had to bend in and do this:
70      * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
71      */
72     unsigned int gdef_len = hb_blob_get_length (layout->gdef_blob);
73     unsigned int gsub_len = hb_blob_get_length (layout->gsub_blob);
74     unsigned int gpos_len = hb_blob_get_length (layout->gpos_blob);
75     if (0
76       /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */
77       || (442 == gdef_len && 42038 == gpos_len && 2874 == gsub_len)
78       /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */
79       || (430 == gdef_len && 40662 == gpos_len && 2874 == gsub_len)
80       /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */
81       || (442 == gdef_len && 39116 == gpos_len && 2874 == gsub_len)
82       /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */
83       || (430 == gdef_len && 39374 == gpos_len && 2874 == gsub_len)
84       /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */
85       || (490 == gdef_len && 41638 == gpos_len && 3046 == gsub_len)
86       /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */
87       || (478 == gdef_len && 41902 == gpos_len && 3046 == gsub_len)
88     )
89     {
90       /* In certain versions of Times New Roman Italic and Bold Italic,
91        * ASCII double quotation mark U+0022, mapped to glyph 5, has wrong
92        * glyph class 3 (mark) in GDEF.  Nuke the GDEF to avoid zero-width
93        * double-quote.  See:
94        * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
95        */
96      if (3 == layout->gdef->get_glyph_class (5))
97        layout->gdef = &OT::Null(OT::GDEF);
98     }
99     else if (0
100       /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c  tahoma.ttf from Windows 8 */
101       || (898 == gdef_len && 46470 == gpos_len && 12554 == gsub_len)
102       /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc  tahomabd.ttf from Windows 8 */
103       || (910 == gdef_len && 47732 == gpos_len && 12566 == gsub_len)
104       /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e  tahoma.ttf from Windows 8.1 */
105       || (928 == gdef_len && 59332 == gpos_len && 23298 == gsub_len)
106       /* sha1sum:6d400781948517c3c0441ba42acb309584b73033  tahomabd.ttf from Windows 8.1 */
107       || (940 == gdef_len && 60732 == gpos_len && 23310 == gsub_len)
108       /* tahoma.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
109       || (964 == gdef_len && 60072 == gpos_len && 23836 == gsub_len)
110       /* tahomabd.ttf v6.04 from Windows 8.1 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
111       || (976 == gdef_len && 61456 == gpos_len && 23832 == gsub_len)
112       /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846  tahoma.ttf from Windows 10 */
113       || (994 == gdef_len && 60336 == gpos_len && 24474 == gsub_len)
114       /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343  tahomabd.ttf from Windows 10 */
115       || (1006 == gdef_len && 61740 == gpos_len && 24470 == gsub_len)
116       /* tahoma.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
117       || (1006 == gdef_len && 61346 == gpos_len && 24576 == gsub_len)
118       /* tahomabd.ttf v6.91 from Windows 10 x64, see https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 */
119       || (1018 == gdef_len && 62828 == gpos_len && 24572 == gsub_len)
120       /* sha1sum:b9c84d820c49850d3d27ec498be93955b82772b5  tahoma.ttf from Windows 10 AU */
121       || (1006 == gdef_len && 61352 == gpos_len && 24576 == gsub_len)
122       /* sha1sum:2bdfaab28174bdadd2f3d4200a30a7ae31db79d2  tahomabd.ttf from Windows 10 AU */
123       || (1018 == gdef_len && 62834 == gpos_len && 24572 == gsub_len)
124       /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7  Tahoma.ttf from Mac OS X 10.9 */
125       || (832 == gdef_len && 47162 == gpos_len && 7324 == gsub_len)
126       /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba  Tahoma Bold.ttf from Mac OS X 10.9 */
127       || (844 == gdef_len && 45474 == gpos_len && 7302 == gsub_len)
128       /* sha1sum:eb8afadd28e9cf963e886b23a30b44ab4fd83acc  himalaya.ttf from Windows 7 */
129       || (180 == gdef_len && 7254 == gpos_len && 13054 == gsub_len)
130       /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0  himalaya.ttf from Windows 8 */
131       || (192 == gdef_len && 7254 == gpos_len && 12638 == gsub_len)
132       /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427  himalaya.ttf from Windows 8.1 */
133       || (192 == gdef_len && 7254 == gpos_len && 12690 == gsub_len)
134       /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44  cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */
135       /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371  cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */
136       || (188 == gdef_len && 3852 == gpos_len && 248 == gsub_len)
137       /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f  cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */
138       /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b  cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */
139       || (188 == gdef_len && 3426 == gpos_len && 264 == gsub_len)
140       /* d125afa82a77a6475ac0e74e7c207914af84b37a padauk-2.80/Padauk.ttf RHEL 7.2 */
141       || (1058 == gdef_len && 11818 == gpos_len && 47032 == gsub_len)
142       /* 0f7b80437227b90a577cc078c0216160ae61b031 padauk-2.80/Padauk-Bold.ttf RHEL 7.2*/
143       || (1046 == gdef_len && 12600 == gpos_len && 47030 == gsub_len)
144       /* d3dde9aa0a6b7f8f6a89ef1002e9aaa11b882290 padauk-2.80/Padauk.ttf Ubuntu 16.04 */
145       || (1058 == gdef_len && 16770 == gpos_len && 71796 == gsub_len)
146       /* 5f3c98ccccae8a953be2d122c1b3a77fd805093f padauk-2.80/Padauk-Bold.ttf Ubuntu 16.04 */
147       || (1046 == gdef_len && 17862 == gpos_len && 71790 == gsub_len)
148       /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */
149       || (1046 == gdef_len && 17112 == gpos_len && 71788 == gsub_len)
150       /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */
151       || (1058 == gdef_len && 17514 == gpos_len && 71794 == gsub_len)
152       /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */
153       || (1330 == gdef_len && 57938 == gpos_len && 109904 == gsub_len)
154       /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */
155       || (1330 == gdef_len && 58972 == gpos_len && 109904 == gsub_len)
156       /* sha1sum: c26e41d567ed821bed997e937bc0c41435689e85  Padauk.ttf
157        *  "Padauk Regular" "Version 2.5", see https://crbug.com/681813 */
158       || (1004 == gdef_len && 14836 == gpos_len && 59092 == gsub_len)
159     )
160     {
161       /* Many versions of Tahoma have bad GDEF tables that incorrectly classify some spacing marks
162        * such as certain IPA symbols as glyph class 3. So do older versions of Microsoft Himalaya,
163        * and the version of Cantarell shipped by Ubuntu 16.04.
164        * Nuke the GDEF tables of these fonts to avoid unwanted width-zeroing.
165        * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925
166        *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279693
167        *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279875
168        */
169       layout->gdef = &OT::Null(OT::GDEF);
170     }
171   }
172 
173   layout->gsub_lookup_count = layout->gsub->get_lookup_count ();
174   layout->gpos_lookup_count = layout->gpos->get_lookup_count ();
175 
176   layout->gsub_accels = (hb_ot_layout_lookup_accelerator_t *) calloc (layout->gsub->get_lookup_count (), sizeof (hb_ot_layout_lookup_accelerator_t));
177   layout->gpos_accels = (hb_ot_layout_lookup_accelerator_t *) calloc (layout->gpos->get_lookup_count (), sizeof (hb_ot_layout_lookup_accelerator_t));
178 
179   if (unlikely ((layout->gsub_lookup_count && !layout->gsub_accels) ||
180 		(layout->gpos_lookup_count && !layout->gpos_accels)))
181   {
182     _hb_ot_layout_destroy (layout);
183     return nullptr;
184   }
185 
186   for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)
187     layout->gsub_accels[i].init (layout->gsub->get_lookup (i));
188   for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)
189     layout->gpos_accels[i].init (layout->gpos->get_lookup (i));
190 
191   return layout;
192 }
193 
194 void
_hb_ot_layout_destroy(hb_ot_layout_t * layout)195 _hb_ot_layout_destroy (hb_ot_layout_t *layout)
196 {
197   for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)
198     layout->gsub_accels[i].fini ();
199   for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)
200     layout->gpos_accels[i].fini ();
201 
202   free (layout->gsub_accels);
203   free (layout->gpos_accels);
204 
205   hb_blob_destroy (layout->gdef_blob);
206   hb_blob_destroy (layout->gsub_blob);
207   hb_blob_destroy (layout->gpos_blob);
208 
209   layout->math.fini ();
210   layout->fvar.fini ();
211   layout->avar.fini ();
212 
213   free (layout);
214 }
215 
216 static inline const OT::GDEF&
_get_gdef(hb_face_t * face)217 _get_gdef (hb_face_t *face)
218 {
219   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GDEF);
220   return *hb_ot_layout_from_face (face)->gdef;
221 }
222 static inline const OT::GSUB&
_get_gsub(hb_face_t * face)223 _get_gsub (hb_face_t *face)
224 {
225   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GSUB);
226   return *hb_ot_layout_from_face (face)->gsub;
227 }
228 static inline const OT::GPOS&
_get_gpos(hb_face_t * face)229 _get_gpos (hb_face_t *face)
230 {
231   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GPOS);
232   return *hb_ot_layout_from_face (face)->gpos;
233 }
234 
235 /*
236  * GDEF
237  */
238 
239 hb_bool_t
hb_ot_layout_has_glyph_classes(hb_face_t * face)240 hb_ot_layout_has_glyph_classes (hb_face_t *face)
241 {
242   return _get_gdef (face).has_glyph_classes ();
243 }
244 
245 /**
246  * hb_ot_layout_get_glyph_class:
247  *
248  * Since: 0.9.7
249  **/
250 hb_ot_layout_glyph_class_t
hb_ot_layout_get_glyph_class(hb_face_t * face,hb_codepoint_t glyph)251 hb_ot_layout_get_glyph_class (hb_face_t      *face,
252 			      hb_codepoint_t  glyph)
253 {
254   return (hb_ot_layout_glyph_class_t) _get_gdef (face).get_glyph_class (glyph);
255 }
256 
257 /**
258  * hb_ot_layout_get_glyphs_in_class:
259  *
260  * Since: 0.9.7
261  **/
262 void
hb_ot_layout_get_glyphs_in_class(hb_face_t * face,hb_ot_layout_glyph_class_t klass,hb_set_t * glyphs)263 hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
264 				  hb_ot_layout_glyph_class_t  klass,
265 				  hb_set_t                   *glyphs /* OUT */)
266 {
267   return _get_gdef (face).get_glyphs_in_class (klass, glyphs);
268 }
269 
270 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)271 hb_ot_layout_get_attach_points (hb_face_t      *face,
272 				hb_codepoint_t  glyph,
273 				unsigned int    start_offset,
274 				unsigned int   *point_count /* IN/OUT */,
275 				unsigned int   *point_array /* OUT */)
276 {
277   return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
278 }
279 
280 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)281 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
282 				  hb_direction_t  direction,
283 				  hb_codepoint_t  glyph,
284 				  unsigned int    start_offset,
285 				  unsigned int   *caret_count /* IN/OUT */,
286 				  hb_position_t  *caret_array /* OUT */)
287 {
288   return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
289 }
290 
291 
292 /*
293  * GSUB/GPOS
294  */
295 
296 static const OT::GSUBGPOS&
get_gsubgpos_table(hb_face_t * face,hb_tag_t table_tag)297 get_gsubgpos_table (hb_face_t *face,
298 		    hb_tag_t   table_tag)
299 {
300   switch (table_tag) {
301     case HB_OT_TAG_GSUB: return _get_gsub (face);
302     case HB_OT_TAG_GPOS: return _get_gpos (face);
303     default:             return OT::Null(OT::GSUBGPOS);
304   }
305 }
306 
307 
308 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)309 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
310 				    hb_tag_t      table_tag,
311 				    unsigned int  start_offset,
312 				    unsigned int *script_count /* IN/OUT */,
313 				    hb_tag_t     *script_tags /* OUT */)
314 {
315   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
316 
317   return g.get_script_tags (start_offset, script_count, script_tags);
318 }
319 
320 #define HB_OT_TAG_LATIN_SCRIPT		HB_TAG ('l', 'a', 't', 'n')
321 
322 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)323 hb_ot_layout_table_find_script (hb_face_t    *face,
324 				hb_tag_t      table_tag,
325 				hb_tag_t      script_tag,
326 				unsigned int *script_index)
327 {
328   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
329   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
330 
331   if (g.find_script_index (script_tag, script_index))
332     return true;
333 
334   /* try finding 'DFLT' */
335   if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
336     return false;
337 
338   /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
339    * including many versions of DejaVu Sans Mono! */
340   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
341     return false;
342 
343   /* try with 'latn'; some old fonts put their features there even though
344      they're really trying to support Thai, for example :( */
345   if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index))
346     return false;
347 
348   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
349   return false;
350 }
351 
352 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)353 hb_ot_layout_table_choose_script (hb_face_t      *face,
354 				  hb_tag_t        table_tag,
355 				  const hb_tag_t *script_tags,
356 				  unsigned int   *script_index,
357 				  hb_tag_t       *chosen_script)
358 {
359   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX), "");
360   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
361 
362   while (*script_tags)
363   {
364     if (g.find_script_index (*script_tags, script_index)) {
365       if (chosen_script)
366         *chosen_script = *script_tags;
367       return true;
368     }
369     script_tags++;
370   }
371 
372   /* try finding 'DFLT' */
373   if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
374     if (chosen_script)
375       *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
376     return false;
377   }
378 
379   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
380   if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
381     if (chosen_script)
382       *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
383     return false;
384   }
385 
386   /* try with 'latn'; some old fonts put their features there even though
387      they're really trying to support Thai, for example :( */
388   if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
389     if (chosen_script)
390       *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
391     return false;
392   }
393 
394   if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
395   if (chosen_script)
396     *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
397   return false;
398 }
399 
400 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)401 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
402 				     hb_tag_t      table_tag,
403 				     unsigned int  start_offset,
404 				     unsigned int *feature_count /* IN/OUT */,
405 				     hb_tag_t     *feature_tags /* OUT */)
406 {
407   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
408 
409   return g.get_feature_tags (start_offset, feature_count, feature_tags);
410 }
411 
412 hb_bool_t
hb_ot_layout_table_find_feature(hb_face_t * face,hb_tag_t table_tag,hb_tag_t feature_tag,unsigned int * feature_index)413 hb_ot_layout_table_find_feature (hb_face_t    *face,
414 				 hb_tag_t      table_tag,
415 				 hb_tag_t      feature_tag,
416 				 unsigned int *feature_index)
417 {
418   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
419   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
420 
421   unsigned int num_features = g.get_feature_count ();
422   for (unsigned int i = 0; i < num_features; i++)
423   {
424     if (feature_tag == g.get_feature_tag (i)) {
425       if (feature_index) *feature_index = i;
426       return true;
427     }
428   }
429 
430   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
431   return false;
432 }
433 
434 
435 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)436 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
437 				       hb_tag_t      table_tag,
438 				       unsigned int  script_index,
439 				       unsigned int  start_offset,
440 				       unsigned int *language_count /* IN/OUT */,
441 				       hb_tag_t     *language_tags /* OUT */)
442 {
443   const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
444 
445   return s.get_lang_sys_tags (start_offset, language_count, language_tags);
446 }
447 
448 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)449 hb_ot_layout_script_find_language (hb_face_t    *face,
450 				   hb_tag_t      table_tag,
451 				   unsigned int  script_index,
452 				   hb_tag_t      language_tag,
453 				   unsigned int *language_index)
454 {
455   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX), "");
456   const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
457 
458   if (s.find_lang_sys_index (language_tag, language_index))
459     return true;
460 
461   /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
462   if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
463     return false;
464 
465   if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
466   return false;
467 }
468 
469 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)470 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
471 						  hb_tag_t      table_tag,
472 						  unsigned int  script_index,
473 						  unsigned int  language_index,
474 						  unsigned int *feature_index)
475 {
476   return hb_ot_layout_language_get_required_feature (face,
477 						     table_tag,
478 						     script_index,
479 						     language_index,
480 						     feature_index,
481 						     nullptr);
482 }
483 
484 /**
485  * hb_ot_layout_language_get_required_feature:
486  *
487  * Since: 0.9.30
488  **/
489 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)490 hb_ot_layout_language_get_required_feature (hb_face_t    *face,
491 					    hb_tag_t      table_tag,
492 					    unsigned int  script_index,
493 					    unsigned int  language_index,
494 					    unsigned int *feature_index,
495 					    hb_tag_t     *feature_tag)
496 {
497   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
498   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
499 
500   unsigned int index = l.get_required_feature_index ();
501   if (feature_index) *feature_index = index;
502   if (feature_tag) *feature_tag = g.get_feature_tag (index);
503 
504   return l.has_required_feature ();
505 }
506 
507 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)508 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
509 					   hb_tag_t      table_tag,
510 					   unsigned int  script_index,
511 					   unsigned int  language_index,
512 					   unsigned int  start_offset,
513 					   unsigned int *feature_count /* IN/OUT */,
514 					   unsigned int *feature_indexes /* OUT */)
515 {
516   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
517   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
518 
519   return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
520 }
521 
522 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)523 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
524 					hb_tag_t      table_tag,
525 					unsigned int  script_index,
526 					unsigned int  language_index,
527 					unsigned int  start_offset,
528 					unsigned int *feature_count /* IN/OUT */,
529 					hb_tag_t     *feature_tags /* OUT */)
530 {
531   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
532   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
533 
534   static_assert ((sizeof (unsigned int) == sizeof (hb_tag_t)), "");
535   unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
536 
537   if (feature_tags) {
538     unsigned int count = *feature_count;
539     for (unsigned int i = 0; i < count; i++)
540       feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
541   }
542 
543   return ret;
544 }
545 
546 
547 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)548 hb_ot_layout_language_find_feature (hb_face_t    *face,
549 				    hb_tag_t      table_tag,
550 				    unsigned int  script_index,
551 				    unsigned int  language_index,
552 				    hb_tag_t      feature_tag,
553 				    unsigned int *feature_index)
554 {
555   static_assert ((OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX), "");
556   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
557   const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
558 
559   unsigned int num_features = l.get_feature_count ();
560   for (unsigned int i = 0; i < num_features; i++) {
561     unsigned int f_index = l.get_feature_index (i);
562 
563     if (feature_tag == g.get_feature_tag (f_index)) {
564       if (feature_index) *feature_index = f_index;
565       return true;
566     }
567   }
568 
569   if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
570   return false;
571 }
572 
573 /**
574  * hb_ot_layout_feature_get_lookups:
575  *
576  * Since: 0.9.7
577  **/
578 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)579 hb_ot_layout_feature_get_lookups (hb_face_t    *face,
580 				  hb_tag_t      table_tag,
581 				  unsigned int  feature_index,
582 				  unsigned int  start_offset,
583 				  unsigned int *lookup_count /* IN/OUT */,
584 				  unsigned int *lookup_indexes /* OUT */)
585 {
586   return hb_ot_layout_feature_with_variations_get_lookups (face,
587 							   table_tag,
588 							   feature_index,
589 							   HB_OT_LAYOUT_NO_VARIATIONS_INDEX,
590 							   start_offset,
591 							   lookup_count,
592 							   lookup_indexes);
593 }
594 
595 /**
596  * hb_ot_layout_table_get_lookup_count:
597  *
598  * Since: 0.9.22
599  **/
600 unsigned int
hb_ot_layout_table_get_lookup_count(hb_face_t * face,hb_tag_t table_tag)601 hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
602 				     hb_tag_t      table_tag)
603 {
604   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return 0;
605   switch (table_tag)
606   {
607     case HB_OT_TAG_GSUB:
608     {
609       return hb_ot_layout_from_face (face)->gsub_lookup_count;
610     }
611     case HB_OT_TAG_GPOS:
612     {
613       return hb_ot_layout_from_face (face)->gpos_lookup_count;
614     }
615   }
616   return 0;
617 }
618 
619 static void
_hb_ot_layout_collect_lookups_lookups(hb_face_t * face,hb_tag_t table_tag,unsigned int feature_index,hb_set_t * lookup_indexes)620 _hb_ot_layout_collect_lookups_lookups (hb_face_t      *face,
621 				       hb_tag_t        table_tag,
622 				       unsigned int    feature_index,
623 				       hb_set_t       *lookup_indexes /* OUT */)
624 {
625   unsigned int lookup_indices[32];
626   unsigned int offset, len;
627 
628   offset = 0;
629   do {
630     len = ARRAY_LENGTH (lookup_indices);
631     hb_ot_layout_feature_get_lookups (face,
632 				      table_tag,
633 				      feature_index,
634 				      offset, &len,
635 				      lookup_indices);
636 
637     for (unsigned int i = 0; i < len; i++)
638       lookup_indexes->add (lookup_indices[i]);
639 
640     offset += len;
641   } while (len == ARRAY_LENGTH (lookup_indices));
642 }
643 
644 static void
_hb_ot_layout_collect_lookups_features(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,unsigned int language_index,const hb_tag_t * features,hb_set_t * lookup_indexes)645 _hb_ot_layout_collect_lookups_features (hb_face_t      *face,
646 					hb_tag_t        table_tag,
647 					unsigned int    script_index,
648 					unsigned int    language_index,
649 					const hb_tag_t *features,
650 					hb_set_t       *lookup_indexes /* OUT */)
651 {
652   if (!features)
653   {
654     unsigned int required_feature_index;
655     if (hb_ot_layout_language_get_required_feature (face,
656 						    table_tag,
657 						    script_index,
658 						    language_index,
659 						    &required_feature_index,
660 						    nullptr))
661       _hb_ot_layout_collect_lookups_lookups (face,
662 					     table_tag,
663 					     required_feature_index,
664 					     lookup_indexes);
665 
666     /* All features */
667     unsigned int feature_indices[32];
668     unsigned int offset, len;
669 
670     offset = 0;
671     do {
672       len = ARRAY_LENGTH (feature_indices);
673       hb_ot_layout_language_get_feature_indexes (face,
674 						 table_tag,
675 						 script_index,
676 						 language_index,
677 						 offset, &len,
678 						 feature_indices);
679 
680       for (unsigned int i = 0; i < len; i++)
681 	_hb_ot_layout_collect_lookups_lookups (face,
682 					       table_tag,
683 					       feature_indices[i],
684 					       lookup_indexes);
685 
686       offset += len;
687     } while (len == ARRAY_LENGTH (feature_indices));
688   }
689   else
690   {
691     for (; *features; features++)
692     {
693       unsigned int feature_index;
694       if (hb_ot_layout_language_find_feature (face,
695 					      table_tag,
696 					      script_index,
697 					      language_index,
698 					      *features,
699 					      &feature_index))
700         _hb_ot_layout_collect_lookups_lookups (face,
701 					       table_tag,
702 					       feature_index,
703 					       lookup_indexes);
704     }
705   }
706 }
707 
708 static void
_hb_ot_layout_collect_lookups_languages(hb_face_t * face,hb_tag_t table_tag,unsigned int script_index,const hb_tag_t * languages,const hb_tag_t * features,hb_set_t * lookup_indexes)709 _hb_ot_layout_collect_lookups_languages (hb_face_t      *face,
710 					 hb_tag_t        table_tag,
711 					 unsigned int    script_index,
712 					 const hb_tag_t *languages,
713 					 const hb_tag_t *features,
714 					 hb_set_t       *lookup_indexes /* OUT */)
715 {
716   _hb_ot_layout_collect_lookups_features (face,
717 					  table_tag,
718 					  script_index,
719 					  HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
720 					  features,
721 					  lookup_indexes);
722 
723   if (!languages)
724   {
725     /* All languages */
726     unsigned int count = hb_ot_layout_script_get_language_tags (face,
727 								table_tag,
728 								script_index,
729 								0, nullptr, nullptr);
730     for (unsigned int language_index = 0; language_index < count; language_index++)
731       _hb_ot_layout_collect_lookups_features (face,
732 					      table_tag,
733 					      script_index,
734 					      language_index,
735 					      features,
736 					      lookup_indexes);
737   }
738   else
739   {
740     for (; *languages; languages++)
741     {
742       unsigned int language_index;
743       if (hb_ot_layout_script_find_language (face,
744 					     table_tag,
745 					     script_index,
746 					     *languages,
747 					     &language_index))
748         _hb_ot_layout_collect_lookups_features (face,
749 						table_tag,
750 						script_index,
751 						language_index,
752 						features,
753 						lookup_indexes);
754     }
755   }
756 }
757 
758 /**
759  * hb_ot_layout_collect_lookups:
760  *
761  * Since: 0.9.8
762  **/
763 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)764 hb_ot_layout_collect_lookups (hb_face_t      *face,
765 			      hb_tag_t        table_tag,
766 			      const hb_tag_t *scripts,
767 			      const hb_tag_t *languages,
768 			      const hb_tag_t *features,
769 			      hb_set_t       *lookup_indexes /* OUT */)
770 {
771   if (!scripts)
772   {
773     /* All scripts */
774     unsigned int count = hb_ot_layout_table_get_script_tags (face,
775 							     table_tag,
776 							     0, nullptr, nullptr);
777     for (unsigned int script_index = 0; script_index < count; script_index++)
778       _hb_ot_layout_collect_lookups_languages (face,
779 					       table_tag,
780 					       script_index,
781 					       languages,
782 					       features,
783 					       lookup_indexes);
784   }
785   else
786   {
787     for (; *scripts; scripts++)
788     {
789       unsigned int script_index;
790       if (hb_ot_layout_table_find_script (face,
791 					  table_tag,
792 					  *scripts,
793 					  &script_index))
794         _hb_ot_layout_collect_lookups_languages (face,
795 						 table_tag,
796 						 script_index,
797 						 languages,
798 						 features,
799 						 lookup_indexes);
800     }
801   }
802 }
803 
804 /**
805  * hb_ot_layout_lookup_collect_glyphs:
806  *
807  * Since: 0.9.7
808  **/
809 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)810 hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
811 				    hb_tag_t      table_tag,
812 				    unsigned int  lookup_index,
813 				    hb_set_t     *glyphs_before, /* OUT. May be nullptr */
814 				    hb_set_t     *glyphs_input,  /* OUT. May be nullptr */
815 				    hb_set_t     *glyphs_after,  /* OUT. May be nullptr */
816 				    hb_set_t     *glyphs_output  /* OUT. May be nullptr */)
817 {
818   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return;
819 
820   OT::hb_collect_glyphs_context_t c (face,
821 				     glyphs_before,
822 				     glyphs_input,
823 				     glyphs_after,
824 				     glyphs_output);
825 
826   switch (table_tag)
827   {
828     case HB_OT_TAG_GSUB:
829     {
830       const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
831       l.collect_glyphs (&c);
832       return;
833     }
834     case HB_OT_TAG_GPOS:
835     {
836       const OT::PosLookup& l = hb_ot_layout_from_face (face)->gpos->get_lookup (lookup_index);
837       l.collect_glyphs (&c);
838       return;
839     }
840   }
841 }
842 
843 
844 /* Variations support */
845 
846 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)847 hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
848 					    hb_tag_t      table_tag,
849 					    const int    *coords,
850 					    unsigned int  num_coords,
851 					    unsigned int *variations_index /* out */)
852 {
853   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
854 
855   return g.find_variations_index (coords, num_coords, variations_index);
856 }
857 
858 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)859 hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
860 						  hb_tag_t      table_tag,
861 						  unsigned int  feature_index,
862 						  unsigned int  variations_index,
863 						  unsigned int  start_offset,
864 						  unsigned int *lookup_count /* IN/OUT */,
865 						  unsigned int *lookup_indexes /* OUT */)
866 {
867   static_assert ((OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX), "");
868   const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
869 
870   const OT::Feature &f = g.get_feature_variation (feature_index, variations_index);
871 
872   return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
873 }
874 
875 
876 /*
877  * OT::GSUB
878  */
879 
880 hb_bool_t
hb_ot_layout_has_substitution(hb_face_t * face)881 hb_ot_layout_has_substitution (hb_face_t *face)
882 {
883   return &_get_gsub (face) != &OT::Null(OT::GSUB);
884 }
885 
886 /**
887  * hb_ot_layout_lookup_would_substitute:
888  *
889  * Since: 0.9.7
890  **/
891 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)892 hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
893 				      unsigned int          lookup_index,
894 				      const hb_codepoint_t *glyphs,
895 				      unsigned int          glyphs_length,
896 				      hb_bool_t             zero_context)
897 {
898   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return false;
899   return hb_ot_layout_lookup_would_substitute_fast (face, lookup_index, glyphs, glyphs_length, zero_context);
900 }
901 
902 hb_bool_t
hb_ot_layout_lookup_would_substitute_fast(hb_face_t * face,unsigned int lookup_index,const hb_codepoint_t * glyphs,unsigned int glyphs_length,hb_bool_t zero_context)903 hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
904 					   unsigned int          lookup_index,
905 					   const hb_codepoint_t *glyphs,
906 					   unsigned int          glyphs_length,
907 					   hb_bool_t             zero_context)
908 {
909   if (unlikely (lookup_index >= hb_ot_layout_from_face (face)->gsub_lookup_count)) return false;
910   OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
911 
912   const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
913 
914   return l.would_apply (&c, &hb_ot_layout_from_face (face)->gsub_accels[lookup_index]);
915 }
916 
917 void
hb_ot_layout_substitute_start(hb_font_t * font,hb_buffer_t * buffer)918 hb_ot_layout_substitute_start (hb_font_t *font, hb_buffer_t *buffer)
919 {
920   OT::GSUB::substitute_start (font, buffer);
921 }
922 
923 /**
924  * hb_ot_layout_lookup_substitute_closure:
925  *
926  * Since: 0.9.7
927  **/
928 void
hb_ot_layout_lookup_substitute_closure(hb_face_t * face,unsigned int lookup_index,hb_set_t * glyphs)929 hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
930 				        unsigned int  lookup_index,
931 				        hb_set_t     *glyphs)
932 {
933   OT::hb_closure_context_t c (face, glyphs);
934 
935   const OT::SubstLookup& l = _get_gsub (face).get_lookup (lookup_index);
936 
937   l.closure (&c);
938 }
939 
940 /*
941  * OT::GPOS
942  */
943 
944 hb_bool_t
hb_ot_layout_has_positioning(hb_face_t * face)945 hb_ot_layout_has_positioning (hb_face_t *face)
946 {
947   return &_get_gpos (face) != &OT::Null(OT::GPOS);
948 }
949 
950 void
hb_ot_layout_position_start(hb_font_t * font,hb_buffer_t * buffer)951 hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
952 {
953   OT::GPOS::position_start (font, buffer);
954 }
955 
956 void
hb_ot_layout_position_finish_advances(hb_font_t * font,hb_buffer_t * buffer)957 hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
958 {
959   OT::GPOS::position_finish_advances (font, buffer);
960 }
961 
962 void
hb_ot_layout_position_finish_offsets(hb_font_t * font,hb_buffer_t * buffer)963 hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
964 {
965   OT::GPOS::position_finish_offsets (font, buffer);
966 }
967 
968 /**
969  * hb_ot_layout_get_size_params:
970  *
971  * Since: 0.9.10
972  **/
973 hb_bool_t
hb_ot_layout_get_size_params(hb_face_t * face,unsigned int * design_size,unsigned int * subfamily_id,unsigned int * subfamily_name_id,unsigned int * range_start,unsigned int * range_end)974 hb_ot_layout_get_size_params (hb_face_t    *face,
975 			      unsigned int *design_size,       /* OUT.  May be nullptr */
976 			      unsigned int *subfamily_id,      /* OUT.  May be nullptr */
977 			      unsigned int *subfamily_name_id, /* OUT.  May be nullptr */
978 			      unsigned int *range_start,       /* OUT.  May be nullptr */
979 			      unsigned int *range_end          /* OUT.  May be nullptr */)
980 {
981   const OT::GPOS &gpos = _get_gpos (face);
982   const hb_tag_t tag = HB_TAG ('s','i','z','e');
983 
984   unsigned int num_features = gpos.get_feature_count ();
985   for (unsigned int i = 0; i < num_features; i++)
986   {
987     if (tag == gpos.get_feature_tag (i))
988     {
989       const OT::Feature &f = gpos.get_feature (i);
990       const OT::FeatureParamsSize &params = f.get_feature_params ().get_size_params (tag);
991 
992       if (params.designSize)
993       {
994 #define PARAM(a, A) if (a) *a = params.A
995 	PARAM (design_size, designSize);
996 	PARAM (subfamily_id, subfamilyID);
997 	PARAM (subfamily_name_id, subfamilyNameID);
998 	PARAM (range_start, rangeStart);
999 	PARAM (range_end, rangeEnd);
1000 #undef PARAM
1001 
1002 	return true;
1003       }
1004     }
1005   }
1006 
1007 #define PARAM(a, A) if (a) *a = 0
1008   PARAM (design_size, designSize);
1009   PARAM (subfamily_id, subfamilyID);
1010   PARAM (subfamily_name_id, subfamilyNameID);
1011   PARAM (range_start, rangeStart);
1012   PARAM (range_end, rangeEnd);
1013 #undef PARAM
1014 
1015   return false;
1016 }
1017 
1018 
1019 /*
1020  * Parts of different types are implemented here such that they have direct
1021  * access to GSUB/GPOS lookups.
1022  */
1023 
1024 
1025 struct GSUBProxy
1026 {
1027   static const unsigned int table_index = 0;
1028   static const bool inplace = false;
1029   typedef OT::SubstLookup Lookup;
1030 
GSUBProxyGSUBProxy1031   GSUBProxy (hb_face_t *face) :
1032     table (*hb_ot_layout_from_face (face)->gsub),
1033     accels (hb_ot_layout_from_face (face)->gsub_accels) {}
1034 
1035   const OT::GSUB &table;
1036   const hb_ot_layout_lookup_accelerator_t *accels;
1037 };
1038 
1039 struct GPOSProxy
1040 {
1041   static const unsigned int table_index = 1;
1042   static const bool inplace = true;
1043   typedef OT::PosLookup Lookup;
1044 
GPOSProxyGPOSProxy1045   GPOSProxy (hb_face_t *face) :
1046     table (*hb_ot_layout_from_face (face)->gpos),
1047     accels (hb_ot_layout_from_face (face)->gpos_accels) {}
1048 
1049   const OT::GPOS &table;
1050   const hb_ot_layout_lookup_accelerator_t *accels;
1051 };
1052 
1053 
1054 struct hb_get_subtables_context_t :
1055        OT::hb_dispatch_context_t<hb_get_subtables_context_t, hb_void_t, HB_DEBUG_APPLY>
1056 {
1057   template <typename Type>
apply_tohb_get_subtables_context_t1058   static inline bool apply_to (const void *obj, OT::hb_apply_context_t *c)
1059   {
1060     const Type *typed_obj = (const Type *) obj;
1061     return typed_obj->apply (c);
1062   }
1063 
1064   typedef bool (*hb_apply_func_t) (const void *obj, OT::hb_apply_context_t *c);
1065 
1066   struct hb_applicable_t
1067   {
inithb_get_subtables_context_t::hb_applicable_t1068     inline void init (const void *obj_, hb_apply_func_t apply_func_)
1069     {
1070       obj = obj_;
1071       apply_func = apply_func_;
1072     }
1073 
applyhb_get_subtables_context_t::hb_applicable_t1074     inline bool apply (OT::hb_apply_context_t *c) const { return apply_func (obj, c); }
1075 
1076     private:
1077     const void *obj;
1078     hb_apply_func_t apply_func;
1079   };
1080 
1081   typedef hb_auto_array_t<hb_applicable_t> array_t;
1082 
1083   /* Dispatch interface. */
get_namehb_get_subtables_context_t1084   inline const char *get_name (void) { return "GET_SUBTABLES"; }
1085   template <typename T>
dispatchhb_get_subtables_context_t1086   inline return_t dispatch (const T &obj)
1087   {
1088     hb_applicable_t *entry = array.push();
1089     if (likely (entry))
1090       entry->init (&obj, apply_to<T>);
1091     return HB_VOID;
1092   }
default_return_valuehb_get_subtables_context_t1093   static return_t default_return_value (void) { return HB_VOID; }
stop_sublookup_iterationhb_get_subtables_context_t1094   bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
1095 
hb_get_subtables_context_thb_get_subtables_context_t1096   hb_get_subtables_context_t (array_t &array_) :
1097 			      array (array_),
1098 			      debug_depth (0) {}
1099 
1100   array_t &array;
1101   unsigned int debug_depth;
1102 };
1103 
1104 static inline bool
apply_forward(OT::hb_apply_context_t * c,const hb_ot_layout_lookup_accelerator_t & accel,const hb_get_subtables_context_t::array_t & subtables)1105 apply_forward (OT::hb_apply_context_t *c,
1106 	       const hb_ot_layout_lookup_accelerator_t &accel,
1107 	       const hb_get_subtables_context_t::array_t &subtables)
1108 {
1109   bool ret = false;
1110   hb_buffer_t *buffer = c->buffer;
1111   while (buffer->idx < buffer->len && !buffer->in_error)
1112   {
1113     bool applied = false;
1114     if (accel.may_have (buffer->cur().codepoint) &&
1115 	(buffer->cur().mask & c->lookup_mask) &&
1116 	c->check_glyph_property (&buffer->cur(), c->lookup_props))
1117      {
1118        for (unsigned int i = 0; i < subtables.len; i++)
1119          if (subtables[i].apply (c))
1120 	 {
1121 	   applied = true;
1122 	   break;
1123 	 }
1124      }
1125 
1126     if (applied)
1127       ret = true;
1128     else
1129       buffer->next_glyph ();
1130   }
1131   return ret;
1132 }
1133 
1134 static inline bool
apply_backward(OT::hb_apply_context_t * c,const hb_ot_layout_lookup_accelerator_t & accel,const hb_get_subtables_context_t::array_t & subtables)1135 apply_backward (OT::hb_apply_context_t *c,
1136 	       const hb_ot_layout_lookup_accelerator_t &accel,
1137 	       const hb_get_subtables_context_t::array_t &subtables)
1138 {
1139   bool ret = false;
1140   hb_buffer_t *buffer = c->buffer;
1141   do
1142   {
1143     if (accel.may_have (buffer->cur().codepoint) &&
1144 	(buffer->cur().mask & c->lookup_mask) &&
1145 	c->check_glyph_property (&buffer->cur(), c->lookup_props))
1146     {
1147      for (unsigned int i = 0; i < subtables.len; i++)
1148        if (subtables[i].apply (c))
1149        {
1150 	 ret = true;
1151 	 break;
1152        }
1153     }
1154     /* The reverse lookup doesn't "advance" cursor (for good reason). */
1155     buffer->idx--;
1156 
1157   }
1158   while ((int) buffer->idx >= 0);
1159   return ret;
1160 }
1161 
1162 template <typename Proxy>
1163 static inline void
apply_string(OT::hb_apply_context_t * c,const typename Proxy::Lookup & lookup,const hb_ot_layout_lookup_accelerator_t & accel)1164 apply_string (OT::hb_apply_context_t *c,
1165 	      const typename Proxy::Lookup &lookup,
1166 	      const hb_ot_layout_lookup_accelerator_t &accel)
1167 {
1168   hb_buffer_t *buffer = c->buffer;
1169 
1170   if (unlikely (!buffer->len || !c->lookup_mask))
1171     return;
1172 
1173   c->set_lookup_props (lookup.get_props ());
1174 
1175   hb_get_subtables_context_t::array_t subtables;
1176   hb_get_subtables_context_t c_get_subtables (subtables);
1177   lookup.dispatch (&c_get_subtables);
1178 
1179   if (likely (!lookup.is_reverse ()))
1180   {
1181     /* in/out forward substitution/positioning */
1182     if (Proxy::table_index == 0)
1183       buffer->clear_output ();
1184     buffer->idx = 0;
1185 
1186     bool ret;
1187     ret = apply_forward (c, accel, subtables);
1188     if (ret)
1189     {
1190       if (!Proxy::inplace)
1191 	buffer->swap_buffers ();
1192       else
1193 	assert (!buffer->has_separate_output ());
1194     }
1195   }
1196   else
1197   {
1198     /* in-place backward substitution/positioning */
1199     if (Proxy::table_index == 0)
1200       buffer->remove_output ();
1201     buffer->idx = buffer->len - 1;
1202 
1203     apply_backward (c, accel, subtables);
1204   }
1205 }
1206 
1207 template <typename Proxy>
apply(const Proxy & proxy,const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const1208 inline void hb_ot_map_t::apply (const Proxy &proxy,
1209 				const hb_ot_shape_plan_t *plan,
1210 				hb_font_t *font,
1211 				hb_buffer_t *buffer) const
1212 {
1213   const unsigned int table_index = proxy.table_index;
1214   unsigned int i = 0;
1215   OT::hb_apply_context_t c (table_index, font, buffer);
1216   c.set_recurse_func (Proxy::Lookup::apply_recurse_func);
1217 
1218   for (unsigned int stage_index = 0; stage_index < stages[table_index].len; stage_index++) {
1219     const stage_map_t *stage = &stages[table_index][stage_index];
1220     for (; i < stage->last_lookup; i++)
1221     {
1222       unsigned int lookup_index = lookups[table_index][i].index;
1223       if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
1224       c.set_lookup_index (lookup_index);
1225       c.set_lookup_mask (lookups[table_index][i].mask);
1226       c.set_auto_zwj (lookups[table_index][i].auto_zwj);
1227       c.set_auto_zwnj (lookups[table_index][i].auto_zwnj);
1228       apply_string<Proxy> (&c,
1229 			   proxy.table.get_lookup (lookup_index),
1230 			   proxy.accels[lookup_index]);
1231       (void) buffer->message (font, "end lookup %d", lookup_index);
1232     }
1233 
1234     if (stage->pause_func)
1235     {
1236       buffer->clear_output ();
1237       stage->pause_func (plan, font, buffer);
1238     }
1239   }
1240 }
1241 
substitute(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const1242 void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1243 {
1244   GSUBProxy proxy (font->face);
1245   apply (proxy, plan, font, buffer);
1246 }
1247 
position(const hb_ot_shape_plan_t * plan,hb_font_t * font,hb_buffer_t * buffer) const1248 void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1249 {
1250   GPOSProxy proxy (font->face);
1251   apply (proxy, plan, font, buffer);
1252 }
1253 
1254 HB_INTERNAL void
hb_ot_layout_substitute_lookup(OT::hb_apply_context_t * c,const OT::SubstLookup & lookup,const hb_ot_layout_lookup_accelerator_t & accel)1255 hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
1256 				const OT::SubstLookup &lookup,
1257 				const hb_ot_layout_lookup_accelerator_t &accel)
1258 {
1259   apply_string<GSUBProxy> (c, lookup, accel);
1260 }
1261