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
39#include "hb-ot-map-private.hh"
40
41
42HB_SHAPER_DATA_ENSURE_DECLARE(ot, face)
43
44hb_ot_layout_t *
45_hb_ot_layout_create (hb_face_t *face)
46{
47  hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
48  if (unlikely (!layout))
49    return NULL;
50
51  layout->gdef_blob = OT::Sanitizer<OT::GDEF>::sanitize (face->reference_table (HB_OT_TAG_GDEF));
52  layout->gdef = OT::Sanitizer<OT::GDEF>::lock_instance (layout->gdef_blob);
53
54  layout->gsub_blob = OT::Sanitizer<OT::GSUB>::sanitize (face->reference_table (HB_OT_TAG_GSUB));
55  layout->gsub = OT::Sanitizer<OT::GSUB>::lock_instance (layout->gsub_blob);
56
57  layout->gpos_blob = OT::Sanitizer<OT::GPOS>::sanitize (face->reference_table (HB_OT_TAG_GPOS));
58  layout->gpos = OT::Sanitizer<OT::GPOS>::lock_instance (layout->gpos_blob);
59
60  layout->math.init (face);
61  layout->fvar.init (face);
62  layout->avar.init (face);
63
64  {
65    /*
66     * The ugly business of blacklisting individual fonts' tables happen here!
67     * See this thread for why we finally had to bend in and do this:
68     * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
69     */
70    unsigned int gdef_len = hb_blob_get_length (layout->gdef_blob);
71    unsigned int gsub_len = hb_blob_get_length (layout->gsub_blob);
72    unsigned int gpos_len = hb_blob_get_length (layout->gpos_blob);
73    if (0
74      /* sha1sum:c5ee92f0bca4bfb7d06c4d03e8cf9f9cf75d2e8a Windows 7? timesi.ttf */
75      || (442 == gdef_len && 42038 == gpos_len && 2874 == gsub_len)
76      /* sha1sum:37fc8c16a0894ab7b749e35579856c73c840867b Windows 7? timesbi.ttf */
77      || (430 == gdef_len && 40662 == gpos_len && 2874 == gsub_len)
78      /* sha1sum:19fc45110ea6cd3cdd0a5faca256a3797a069a80 Windows 7 timesi.ttf */
79      || (442 == gdef_len && 39116 == gpos_len && 2874 == gsub_len)
80      /* sha1sum:6d2d3c9ed5b7de87bc84eae0df95ee5232ecde26 Windows 7 timesbi.ttf */
81      || (430 == gdef_len && 39374 == gpos_len && 2874 == gsub_len)
82      /* sha1sum:8583225a8b49667c077b3525333f84af08c6bcd8 OS X 10.11.3 Times New Roman Italic.ttf */
83      || (490 == gdef_len && 41638 == gpos_len && 3046 == gsub_len)
84      /* sha1sum:ec0f5a8751845355b7c3271d11f9918a966cb8c9 OS X 10.11.3 Times New Roman Bold Italic.ttf */
85      || (478 == gdef_len && 41902 == gpos_len && 3046 == gsub_len)
86    )
87    {
88      /* In certain versions of Times New Roman Italic and Bold Italic,
89       * ASCII double quotation mark U+0022, mapped to glyph 5, has wrong
90       * glyph class 3 (mark) in GDEF.  Nuke the GDEF to avoid zero-width
91       * double-quote.  See:
92       * https://lists.freedesktop.org/archives/harfbuzz/2016-February/005489.html
93       */
94     if (3 == layout->gdef->get_glyph_class (5))
95       layout->gdef = &OT::Null(OT::GDEF);
96    }
97    else if (0
98      /* sha1sum:96eda93f7d33e79962451c6c39a6b51ee893ce8c  tahoma.ttf from Windows 8 */
99      || (898 == gdef_len && 46470 == gpos_len && 12554 == gsub_len)
100      /* sha1sum:20928dc06014e0cd120b6fc942d0c3b1a46ac2bc  tahomabd.ttf from Windows 8 */
101      || (910 == gdef_len && 47732 == gpos_len && 12566 == gsub_len)
102      /* sha1sum:4f95b7e4878f60fa3a39ca269618dfde9721a79e  tahoma.ttf from Windows 8.1 */
103      || (928 == gdef_len && 59332 == gpos_len && 23298 == gsub_len)
104      /* sha1sum:6d400781948517c3c0441ba42acb309584b73033  tahomabd.ttf from Windows 8.1 */
105      || (940 == gdef_len && 60732 == gpos_len && 23310 == gsub_len)
106      /* sha1sum:e55fa2dfe957a9f7ec26be516a0e30b0c925f846  tahoma.ttf from Windows 10 */
107      || (994 == gdef_len && 60336 == gpos_len && 24474 == gsub_len)
108      /* sha1sum:7199385abb4c2cc81c83a151a7599b6368e92343  tahomabd.ttf from Windows 10 */
109      || (1006 == gdef_len && 61740 == gpos_len && 24470 == gsub_len)
110      /* sha1sum:b0d36cf5a2fbe746a3dd277bffc6756a820807a7  Tahoma.ttf from Mac OS X 10.9 */
111      || (832 == gdef_len && 47162 == gpos_len && 7324 == gsub_len)
112      /* sha1sum:12fc4538e84d461771b30c18b5eb6bd434e30fba  Tahoma Bold.ttf from Mac OS X 10.9 */
113      || (844 == gdef_len && 45474 == gpos_len && 7302 == gsub_len)
114      /* sha1sum:73da7f025b238a3f737aa1fde22577a6370f77b0  himalaya.ttf from Windows 8 */
115      || (192 == gdef_len && 7254 == gpos_len && 12638 == gsub_len)
116      /* sha1sum:6e80fd1c0b059bbee49272401583160dc1e6a427  himalaya.ttf from Windows 8.1 */
117      || (192 == gdef_len && 7254 == gpos_len && 12690 == gsub_len)
118      /* 8d9267aea9cd2c852ecfb9f12a6e834bfaeafe44  cantarell-fonts-0.0.21/otf/Cantarell-Regular.otf */
119      /* 983988ff7b47439ab79aeaf9a45bd4a2c5b9d371  cantarell-fonts-0.0.21/otf/Cantarell-Oblique.otf */
120      || (188 == gdef_len && 3852 == gpos_len && 248 == gsub_len)
121      /* 2c0c90c6f6087ffbfea76589c93113a9cbb0e75f  cantarell-fonts-0.0.21/otf/Cantarell-Bold.otf */
122      /* 55461f5b853c6da88069ffcdf7f4dd3f8d7e3e6b  cantarell-fonts-0.0.21/otf/Cantarell-Bold-Oblique.otf */
123      || (188 == gdef_len && 3426 == gpos_len && 264 == gsub_len)
124      /* 6c93b63b64e8b2c93f5e824e78caca555dc887c7 padauk-2.80/Padauk-book.ttf */
125      || (1046 == gdef_len && 17112 == gpos_len && 71788 == gsub_len)
126      /* d89b1664058359b8ec82e35d3531931125991fb9 padauk-2.80/Padauk-bookbold.ttf */
127      || (1058 == gdef_len && 17514 == gpos_len && 71794 == gsub_len)
128      /* 824cfd193aaf6234b2b4dc0cf3c6ef576c0d00ef padauk-3.0/Padauk-book.ttf */
129      || (1330 == gdef_len && 57938 == gpos_len && 109904 == gsub_len)
130      /* 91fcc10cf15e012d27571e075b3b4dfe31754a8a padauk-3.0/Padauk-bookbold.ttf */
131      || (1330 == gdef_len && 58972 == gpos_len && 109904 == gsub_len)
132    )
133    {
134      /* Many versions of Tahoma have bad GDEF tables that incorrectly classify some spacing marks
135       * such as certain IPA symbols as glyph class 3. So do older versions of Microsoft Himalaya,
136       * and the version of Cantarell shipped by Ubuntu 16.04.
137       * Nuke the GDEF tables of these fonts to avoid unwanted width-zeroing.
138       * See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925
139       *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279693
140       *     https://bugzilla.mozilla.org/show_bug.cgi?id=1279875
141       */
142      layout->gdef = &OT::Null(OT::GDEF);
143    }
144  }
145
146  layout->gsub_lookup_count = layout->gsub->get_lookup_count ();
147  layout->gpos_lookup_count = layout->gpos->get_lookup_count ();
148
149  layout->gsub_accels = (hb_ot_layout_lookup_accelerator_t *) calloc (layout->gsub->get_lookup_count (), sizeof (hb_ot_layout_lookup_accelerator_t));
150  layout->gpos_accels = (hb_ot_layout_lookup_accelerator_t *) calloc (layout->gpos->get_lookup_count (), sizeof (hb_ot_layout_lookup_accelerator_t));
151
152  if (unlikely ((layout->gsub_lookup_count && !layout->gsub_accels) ||
153		(layout->gpos_lookup_count && !layout->gpos_accels)))
154  {
155    _hb_ot_layout_destroy (layout);
156    return NULL;
157  }
158
159  for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)
160    layout->gsub_accels[i].init (layout->gsub->get_lookup (i));
161  for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)
162    layout->gpos_accels[i].init (layout->gpos->get_lookup (i));
163
164  return layout;
165}
166
167void
168_hb_ot_layout_destroy (hb_ot_layout_t *layout)
169{
170  for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)
171    layout->gsub_accels[i].fini ();
172  for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)
173    layout->gpos_accels[i].fini ();
174
175  free (layout->gsub_accels);
176  free (layout->gpos_accels);
177
178  hb_blob_destroy (layout->gdef_blob);
179  hb_blob_destroy (layout->gsub_blob);
180  hb_blob_destroy (layout->gpos_blob);
181
182  layout->math.fini ();
183  layout->fvar.fini ();
184  layout->avar.fini ();
185
186  free (layout);
187}
188
189static inline const OT::GDEF&
190_get_gdef (hb_face_t *face)
191{
192  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GDEF);
193  return *hb_ot_layout_from_face (face)->gdef;
194}
195static inline const OT::GSUB&
196_get_gsub (hb_face_t *face)
197{
198  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GSUB);
199  return *hb_ot_layout_from_face (face)->gsub;
200}
201static inline const OT::GPOS&
202_get_gpos (hb_face_t *face)
203{
204  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GPOS);
205  return *hb_ot_layout_from_face (face)->gpos;
206}
207
208/*
209 * GDEF
210 */
211
212hb_bool_t
213hb_ot_layout_has_glyph_classes (hb_face_t *face)
214{
215  return _get_gdef (face).has_glyph_classes ();
216}
217
218/**
219 * hb_ot_layout_get_glyph_class:
220 *
221 * Since: 0.9.7
222 **/
223hb_ot_layout_glyph_class_t
224hb_ot_layout_get_glyph_class (hb_face_t      *face,
225			      hb_codepoint_t  glyph)
226{
227  return (hb_ot_layout_glyph_class_t) _get_gdef (face).get_glyph_class (glyph);
228}
229
230/**
231 * hb_ot_layout_get_glyphs_in_class:
232 *
233 * Since: 0.9.7
234 **/
235void
236hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
237				  hb_ot_layout_glyph_class_t  klass,
238				  hb_set_t                   *glyphs /* OUT */)
239{
240  return _get_gdef (face).get_glyphs_in_class (klass, glyphs);
241}
242
243unsigned int
244hb_ot_layout_get_attach_points (hb_face_t      *face,
245				hb_codepoint_t  glyph,
246				unsigned int    start_offset,
247				unsigned int   *point_count /* IN/OUT */,
248				unsigned int   *point_array /* OUT */)
249{
250  return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
251}
252
253unsigned int
254hb_ot_layout_get_ligature_carets (hb_font_t      *font,
255				  hb_direction_t  direction,
256				  hb_codepoint_t  glyph,
257				  unsigned int    start_offset,
258				  unsigned int   *caret_count /* IN/OUT */,
259				  int            *caret_array /* OUT */)
260{
261  return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
262}
263
264
265/*
266 * GSUB/GPOS
267 */
268
269static const OT::GSUBGPOS&
270get_gsubgpos_table (hb_face_t *face,
271		    hb_tag_t   table_tag)
272{
273  switch (table_tag) {
274    case HB_OT_TAG_GSUB: return _get_gsub (face);
275    case HB_OT_TAG_GPOS: return _get_gpos (face);
276    default:             return OT::Null(OT::GSUBGPOS);
277  }
278}
279
280
281unsigned int
282hb_ot_layout_table_get_script_tags (hb_face_t    *face,
283				    hb_tag_t      table_tag,
284				    unsigned int  start_offset,
285				    unsigned int *script_count /* IN/OUT */,
286				    hb_tag_t     *script_tags /* OUT */)
287{
288  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
289
290  return g.get_script_tags (start_offset, script_count, script_tags);
291}
292
293#define HB_OT_TAG_LATIN_SCRIPT		HB_TAG ('l', 'a', 't', 'n')
294
295hb_bool_t
296hb_ot_layout_table_find_script (hb_face_t    *face,
297				hb_tag_t      table_tag,
298				hb_tag_t      script_tag,
299				unsigned int *script_index)
300{
301  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
302  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
303
304  if (g.find_script_index (script_tag, script_index))
305    return true;
306
307  /* try finding 'DFLT' */
308  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
309    return false;
310
311  /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
312   * including many versions of DejaVu Sans Mono! */
313  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
314    return false;
315
316  /* try with 'latn'; some old fonts put their features there even though
317     they're really trying to support Thai, for example :( */
318  if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index))
319    return false;
320
321  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
322  return false;
323}
324
325hb_bool_t
326hb_ot_layout_table_choose_script (hb_face_t      *face,
327				  hb_tag_t        table_tag,
328				  const hb_tag_t *script_tags,
329				  unsigned int   *script_index,
330				  hb_tag_t       *chosen_script)
331{
332  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
333  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
334
335  while (*script_tags)
336  {
337    if (g.find_script_index (*script_tags, script_index)) {
338      if (chosen_script)
339        *chosen_script = *script_tags;
340      return true;
341    }
342    script_tags++;
343  }
344
345  /* try finding 'DFLT' */
346  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
347    if (chosen_script)
348      *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
349    return false;
350  }
351
352  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
353  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
354    if (chosen_script)
355      *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
356    return false;
357  }
358
359  /* try with 'latn'; some old fonts put their features there even though
360     they're really trying to support Thai, for example :( */
361  if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
362    if (chosen_script)
363      *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
364    return false;
365  }
366
367  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
368  if (chosen_script)
369    *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
370  return false;
371}
372
373unsigned int
374hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
375				     hb_tag_t      table_tag,
376				     unsigned int  start_offset,
377				     unsigned int *feature_count /* IN/OUT */,
378				     hb_tag_t     *feature_tags /* OUT */)
379{
380  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
381
382  return g.get_feature_tags (start_offset, feature_count, feature_tags);
383}
384
385hb_bool_t
386hb_ot_layout_table_find_feature (hb_face_t    *face,
387				 hb_tag_t      table_tag,
388				 hb_tag_t      feature_tag,
389				 unsigned int *feature_index)
390{
391  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
392  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
393
394  unsigned int num_features = g.get_feature_count ();
395  for (unsigned int i = 0; i < num_features; i++)
396  {
397    if (feature_tag == g.get_feature_tag (i)) {
398      if (feature_index) *feature_index = i;
399      return true;
400    }
401  }
402
403  if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
404  return false;
405}
406
407
408unsigned int
409hb_ot_layout_script_get_language_tags (hb_face_t    *face,
410				       hb_tag_t      table_tag,
411				       unsigned int  script_index,
412				       unsigned int  start_offset,
413				       unsigned int *language_count /* IN/OUT */,
414				       hb_tag_t     *language_tags /* OUT */)
415{
416  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
417
418  return s.get_lang_sys_tags (start_offset, language_count, language_tags);
419}
420
421hb_bool_t
422hb_ot_layout_script_find_language (hb_face_t    *face,
423				   hb_tag_t      table_tag,
424				   unsigned int  script_index,
425				   hb_tag_t      language_tag,
426				   unsigned int *language_index)
427{
428  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
429  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
430
431  if (s.find_lang_sys_index (language_tag, language_index))
432    return true;
433
434  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
435  if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
436    return false;
437
438  if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
439  return false;
440}
441
442hb_bool_t
443hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
444						  hb_tag_t      table_tag,
445						  unsigned int  script_index,
446						  unsigned int  language_index,
447						  unsigned int *feature_index)
448{
449  return hb_ot_layout_language_get_required_feature (face,
450						     table_tag,
451						     script_index,
452						     language_index,
453						     feature_index,
454						     NULL);
455}
456
457/**
458 * hb_ot_layout_language_get_required_feature:
459 *
460 * Since: 0.9.30
461 **/
462hb_bool_t
463hb_ot_layout_language_get_required_feature (hb_face_t    *face,
464					    hb_tag_t      table_tag,
465					    unsigned int  script_index,
466					    unsigned int  language_index,
467					    unsigned int *feature_index,
468					    hb_tag_t     *feature_tag)
469{
470  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
471  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
472
473  unsigned int index = l.get_required_feature_index ();
474  if (feature_index) *feature_index = index;
475  if (feature_tag) *feature_tag = g.get_feature_tag (index);
476
477  return l.has_required_feature ();
478}
479
480unsigned int
481hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
482					   hb_tag_t      table_tag,
483					   unsigned int  script_index,
484					   unsigned int  language_index,
485					   unsigned int  start_offset,
486					   unsigned int *feature_count /* IN/OUT */,
487					   unsigned int *feature_indexes /* OUT */)
488{
489  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
490  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
491
492  return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
493}
494
495unsigned int
496hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
497					hb_tag_t      table_tag,
498					unsigned int  script_index,
499					unsigned int  language_index,
500					unsigned int  start_offset,
501					unsigned int *feature_count /* IN/OUT */,
502					hb_tag_t     *feature_tags /* OUT */)
503{
504  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
505  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
506
507  ASSERT_STATIC (sizeof (unsigned int) == sizeof (hb_tag_t));
508  unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
509
510  if (feature_tags) {
511    unsigned int count = *feature_count;
512    for (unsigned int i = 0; i < count; i++)
513      feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
514  }
515
516  return ret;
517}
518
519
520hb_bool_t
521hb_ot_layout_language_find_feature (hb_face_t    *face,
522				    hb_tag_t      table_tag,
523				    unsigned int  script_index,
524				    unsigned int  language_index,
525				    hb_tag_t      feature_tag,
526				    unsigned int *feature_index)
527{
528  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
529  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
530  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
531
532  unsigned int num_features = l.get_feature_count ();
533  for (unsigned int i = 0; i < num_features; i++) {
534    unsigned int f_index = l.get_feature_index (i);
535
536    if (feature_tag == g.get_feature_tag (f_index)) {
537      if (feature_index) *feature_index = f_index;
538      return true;
539    }
540  }
541
542  if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
543  return false;
544}
545
546/**
547 * hb_ot_layout_feature_get_lookups:
548 *
549 * Since: 0.9.7
550 **/
551unsigned int
552hb_ot_layout_feature_get_lookups (hb_face_t    *face,
553				  hb_tag_t      table_tag,
554				  unsigned int  feature_index,
555				  unsigned int  start_offset,
556				  unsigned int *lookup_count /* IN/OUT */,
557				  unsigned int *lookup_indexes /* OUT */)
558{
559  return hb_ot_layout_feature_with_variations_get_lookups (face,
560							   table_tag,
561							   feature_index,
562							   HB_OT_LAYOUT_NO_VARIATIONS_INDEX,
563							   start_offset,
564							   lookup_count,
565							   lookup_indexes);
566}
567
568/**
569 * hb_ot_layout_table_get_lookup_count:
570 *
571 * Since: 0.9.22
572 **/
573unsigned int
574hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
575				     hb_tag_t      table_tag)
576{
577  switch (table_tag)
578  {
579    case HB_OT_TAG_GSUB:
580    {
581      return hb_ot_layout_from_face (face)->gsub_lookup_count;
582    }
583    case HB_OT_TAG_GPOS:
584    {
585      return hb_ot_layout_from_face (face)->gpos_lookup_count;
586    }
587  }
588  return 0;
589}
590
591static void
592_hb_ot_layout_collect_lookups_lookups (hb_face_t      *face,
593				       hb_tag_t        table_tag,
594				       unsigned int    feature_index,
595				       hb_set_t       *lookup_indexes /* OUT */)
596{
597  unsigned int lookup_indices[32];
598  unsigned int offset, len;
599
600  offset = 0;
601  do {
602    len = ARRAY_LENGTH (lookup_indices);
603    hb_ot_layout_feature_get_lookups (face,
604				      table_tag,
605				      feature_index,
606				      offset, &len,
607				      lookup_indices);
608
609    for (unsigned int i = 0; i < len; i++)
610      lookup_indexes->add (lookup_indices[i]);
611
612    offset += len;
613  } while (len == ARRAY_LENGTH (lookup_indices));
614}
615
616static void
617_hb_ot_layout_collect_lookups_features (hb_face_t      *face,
618					hb_tag_t        table_tag,
619					unsigned int    script_index,
620					unsigned int    language_index,
621					const hb_tag_t *features,
622					hb_set_t       *lookup_indexes /* OUT */)
623{
624  if (!features)
625  {
626    unsigned int required_feature_index;
627    if (hb_ot_layout_language_get_required_feature (face,
628						    table_tag,
629						    script_index,
630						    language_index,
631						    &required_feature_index,
632						    NULL))
633      _hb_ot_layout_collect_lookups_lookups (face,
634					     table_tag,
635					     required_feature_index,
636					     lookup_indexes);
637
638    /* All features */
639    unsigned int feature_indices[32];
640    unsigned int offset, len;
641
642    offset = 0;
643    do {
644      len = ARRAY_LENGTH (feature_indices);
645      hb_ot_layout_language_get_feature_indexes (face,
646						 table_tag,
647						 script_index,
648						 language_index,
649						 offset, &len,
650						 feature_indices);
651
652      for (unsigned int i = 0; i < len; i++)
653	_hb_ot_layout_collect_lookups_lookups (face,
654					       table_tag,
655					       feature_indices[i],
656					       lookup_indexes);
657
658      offset += len;
659    } while (len == ARRAY_LENGTH (feature_indices));
660  }
661  else
662  {
663    for (; *features; features++)
664    {
665      unsigned int feature_index;
666      if (hb_ot_layout_language_find_feature (face,
667					      table_tag,
668					      script_index,
669					      language_index,
670					      *features,
671					      &feature_index))
672        _hb_ot_layout_collect_lookups_lookups (face,
673					       table_tag,
674					       feature_index,
675					       lookup_indexes);
676    }
677  }
678}
679
680static void
681_hb_ot_layout_collect_lookups_languages (hb_face_t      *face,
682					 hb_tag_t        table_tag,
683					 unsigned int    script_index,
684					 const hb_tag_t *languages,
685					 const hb_tag_t *features,
686					 hb_set_t       *lookup_indexes /* OUT */)
687{
688  _hb_ot_layout_collect_lookups_features (face,
689					  table_tag,
690					  script_index,
691					  HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
692					  features,
693					  lookup_indexes);
694
695  if (!languages)
696  {
697    /* All languages */
698    unsigned int count = hb_ot_layout_script_get_language_tags (face,
699								table_tag,
700								script_index,
701								0, NULL, NULL);
702    for (unsigned int language_index = 0; language_index < count; language_index++)
703      _hb_ot_layout_collect_lookups_features (face,
704					      table_tag,
705					      script_index,
706					      language_index,
707					      features,
708					      lookup_indexes);
709  }
710  else
711  {
712    for (; *languages; languages++)
713    {
714      unsigned int language_index;
715      if (hb_ot_layout_script_find_language (face,
716					     table_tag,
717					     script_index,
718					     *languages,
719					     &language_index))
720        _hb_ot_layout_collect_lookups_features (face,
721						table_tag,
722						script_index,
723						language_index,
724						features,
725						lookup_indexes);
726    }
727  }
728}
729
730/**
731 * hb_ot_layout_collect_lookups:
732 *
733 * Since: 0.9.8
734 **/
735void
736hb_ot_layout_collect_lookups (hb_face_t      *face,
737			      hb_tag_t        table_tag,
738			      const hb_tag_t *scripts,
739			      const hb_tag_t *languages,
740			      const hb_tag_t *features,
741			      hb_set_t       *lookup_indexes /* OUT */)
742{
743  if (!scripts)
744  {
745    /* All scripts */
746    unsigned int count = hb_ot_layout_table_get_script_tags (face,
747							     table_tag,
748							     0, NULL, NULL);
749    for (unsigned int script_index = 0; script_index < count; script_index++)
750      _hb_ot_layout_collect_lookups_languages (face,
751					       table_tag,
752					       script_index,
753					       languages,
754					       features,
755					       lookup_indexes);
756  }
757  else
758  {
759    for (; *scripts; scripts++)
760    {
761      unsigned int script_index;
762      if (hb_ot_layout_table_find_script (face,
763					  table_tag,
764					  *scripts,
765					  &script_index))
766        _hb_ot_layout_collect_lookups_languages (face,
767						 table_tag,
768						 script_index,
769						 languages,
770						 features,
771						 lookup_indexes);
772    }
773  }
774}
775
776/**
777 * hb_ot_layout_lookup_collect_glyphs:
778 *
779 * Since: 0.9.7
780 **/
781void
782hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
783				    hb_tag_t      table_tag,
784				    unsigned int  lookup_index,
785				    hb_set_t     *glyphs_before, /* OUT. May be NULL */
786				    hb_set_t     *glyphs_input,  /* OUT. May be NULL */
787				    hb_set_t     *glyphs_after,  /* OUT. May be NULL */
788				    hb_set_t     *glyphs_output  /* OUT. May be NULL */)
789{
790  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return;
791
792  OT::hb_collect_glyphs_context_t c (face,
793				     glyphs_before,
794				     glyphs_input,
795				     glyphs_after,
796				     glyphs_output);
797
798  switch (table_tag)
799  {
800    case HB_OT_TAG_GSUB:
801    {
802      const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
803      l.collect_glyphs (&c);
804      return;
805    }
806    case HB_OT_TAG_GPOS:
807    {
808      const OT::PosLookup& l = hb_ot_layout_from_face (face)->gpos->get_lookup (lookup_index);
809      l.collect_glyphs (&c);
810      return;
811    }
812  }
813}
814
815
816/* Variations support */
817
818hb_bool_t
819hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
820					    hb_tag_t      table_tag,
821					    const int    *coords,
822					    unsigned int  num_coords,
823					    unsigned int *variations_index /* out */)
824{
825  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
826
827  return g.find_variations_index (coords, num_coords, variations_index);
828}
829
830unsigned int
831hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
832						  hb_tag_t      table_tag,
833						  unsigned int  feature_index,
834						  unsigned int  variations_index,
835						  unsigned int  start_offset,
836						  unsigned int *lookup_count /* IN/OUT */,
837						  unsigned int *lookup_indexes /* OUT */)
838{
839  ASSERT_STATIC (OT::FeatureVariations::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_VARIATIONS_INDEX);
840  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
841
842  const OT::Feature &f = g.get_feature_variation (feature_index, variations_index);
843
844  return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
845}
846
847
848/*
849 * OT::GSUB
850 */
851
852hb_bool_t
853hb_ot_layout_has_substitution (hb_face_t *face)
854{
855  return &_get_gsub (face) != &OT::Null(OT::GSUB);
856}
857
858/**
859 * hb_ot_layout_lookup_would_substitute:
860 *
861 * Since: 0.9.7
862 **/
863hb_bool_t
864hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
865				      unsigned int          lookup_index,
866				      const hb_codepoint_t *glyphs,
867				      unsigned int          glyphs_length,
868				      hb_bool_t             zero_context)
869{
870  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return false;
871  return hb_ot_layout_lookup_would_substitute_fast (face, lookup_index, glyphs, glyphs_length, zero_context);
872}
873
874hb_bool_t
875hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
876					   unsigned int          lookup_index,
877					   const hb_codepoint_t *glyphs,
878					   unsigned int          glyphs_length,
879					   hb_bool_t             zero_context)
880{
881  if (unlikely (lookup_index >= hb_ot_layout_from_face (face)->gsub_lookup_count)) return false;
882  OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
883
884  const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
885
886  return l.would_apply (&c, &hb_ot_layout_from_face (face)->gsub_accels[lookup_index]);
887}
888
889void
890hb_ot_layout_substitute_start (hb_font_t *font, hb_buffer_t *buffer)
891{
892  OT::GSUB::substitute_start (font, buffer);
893}
894
895/**
896 * hb_ot_layout_lookup_substitute_closure:
897 *
898 * Since: 0.9.7
899 **/
900void
901hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
902				        unsigned int  lookup_index,
903				        hb_set_t     *glyphs)
904{
905  OT::hb_closure_context_t c (face, glyphs);
906
907  const OT::SubstLookup& l = _get_gsub (face).get_lookup (lookup_index);
908
909  l.closure (&c);
910}
911
912/*
913 * OT::GPOS
914 */
915
916hb_bool_t
917hb_ot_layout_has_positioning (hb_face_t *face)
918{
919  return &_get_gpos (face) != &OT::Null(OT::GPOS);
920}
921
922void
923hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
924{
925  OT::GPOS::position_start (font, buffer);
926}
927
928void
929hb_ot_layout_position_finish_advances (hb_font_t *font, hb_buffer_t *buffer)
930{
931  OT::GPOS::position_finish_advances (font, buffer);
932}
933
934void
935hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
936{
937  OT::GPOS::position_finish_offsets (font, buffer);
938}
939
940/**
941 * hb_ot_layout_get_size_params:
942 *
943 * Since: 0.9.10
944 **/
945hb_bool_t
946hb_ot_layout_get_size_params (hb_face_t    *face,
947			      unsigned int *design_size,       /* OUT.  May be NULL */
948			      unsigned int *subfamily_id,      /* OUT.  May be NULL */
949			      unsigned int *subfamily_name_id, /* OUT.  May be NULL */
950			      unsigned int *range_start,       /* OUT.  May be NULL */
951			      unsigned int *range_end          /* OUT.  May be NULL */)
952{
953  const OT::GPOS &gpos = _get_gpos (face);
954  const hb_tag_t tag = HB_TAG ('s','i','z','e');
955
956  unsigned int num_features = gpos.get_feature_count ();
957  for (unsigned int i = 0; i < num_features; i++)
958  {
959    if (tag == gpos.get_feature_tag (i))
960    {
961      const OT::Feature &f = gpos.get_feature (i);
962      const OT::FeatureParamsSize &params = f.get_feature_params ().get_size_params (tag);
963
964      if (params.designSize)
965      {
966#define PARAM(a, A) if (a) *a = params.A
967	PARAM (design_size, designSize);
968	PARAM (subfamily_id, subfamilyID);
969	PARAM (subfamily_name_id, subfamilyNameID);
970	PARAM (range_start, rangeStart);
971	PARAM (range_end, rangeEnd);
972#undef PARAM
973
974	return true;
975      }
976    }
977  }
978
979#define PARAM(a, A) if (a) *a = 0
980  PARAM (design_size, designSize);
981  PARAM (subfamily_id, subfamilyID);
982  PARAM (subfamily_name_id, subfamilyNameID);
983  PARAM (range_start, rangeStart);
984  PARAM (range_end, rangeEnd);
985#undef PARAM
986
987  return false;
988}
989
990
991/*
992 * Parts of different types are implemented here such that they have direct
993 * access to GSUB/GPOS lookups.
994 */
995
996
997struct GSUBProxy
998{
999  static const unsigned int table_index = 0;
1000  static const bool inplace = false;
1001  typedef OT::SubstLookup Lookup;
1002
1003  GSUBProxy (hb_face_t *face) :
1004    table (*hb_ot_layout_from_face (face)->gsub),
1005    accels (hb_ot_layout_from_face (face)->gsub_accels) {}
1006
1007  const OT::GSUB &table;
1008  const hb_ot_layout_lookup_accelerator_t *accels;
1009};
1010
1011struct GPOSProxy
1012{
1013  static const unsigned int table_index = 1;
1014  static const bool inplace = true;
1015  typedef OT::PosLookup Lookup;
1016
1017  GPOSProxy (hb_face_t *face) :
1018    table (*hb_ot_layout_from_face (face)->gpos),
1019    accels (hb_ot_layout_from_face (face)->gpos_accels) {}
1020
1021  const OT::GPOS &table;
1022  const hb_ot_layout_lookup_accelerator_t *accels;
1023};
1024
1025
1026struct hb_get_subtables_context_t :
1027       OT::hb_dispatch_context_t<hb_get_subtables_context_t, hb_void_t, HB_DEBUG_APPLY>
1028{
1029  template <typename Type>
1030  static inline bool apply_to (const void *obj, OT::hb_apply_context_t *c)
1031  {
1032    const Type *typed_obj = (const Type *) obj;
1033    return typed_obj->apply (c);
1034  }
1035
1036  typedef bool (*hb_apply_func_t) (const void *obj, OT::hb_apply_context_t *c);
1037
1038  struct hb_applicable_t
1039  {
1040    inline void init (const void *obj_, hb_apply_func_t apply_func_)
1041    {
1042      obj = obj_;
1043      apply_func = apply_func_;
1044    }
1045
1046    inline bool apply (OT::hb_apply_context_t *c) const { return apply_func (obj, c); }
1047
1048    private:
1049    const void *obj;
1050    hb_apply_func_t apply_func;
1051  };
1052
1053  typedef hb_auto_array_t<hb_applicable_t> array_t;
1054
1055  /* Dispatch interface. */
1056  inline const char *get_name (void) { return "GET_SUBTABLES"; }
1057  template <typename T>
1058  inline return_t dispatch (const T &obj)
1059  {
1060    hb_applicable_t *entry = array.push();
1061    if (likely (entry))
1062      entry->init (&obj, apply_to<T>);
1063    return HB_VOID;
1064  }
1065  static return_t default_return_value (void) { return HB_VOID; }
1066  bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
1067
1068  hb_get_subtables_context_t (array_t &array_) :
1069			      array (array_),
1070			      debug_depth (0) {}
1071
1072  array_t &array;
1073  unsigned int debug_depth;
1074};
1075
1076static inline bool
1077apply_forward (OT::hb_apply_context_t *c,
1078	       const hb_ot_layout_lookup_accelerator_t &accel,
1079	       const hb_get_subtables_context_t::array_t &subtables)
1080{
1081  bool ret = false;
1082  hb_buffer_t *buffer = c->buffer;
1083  while (buffer->idx < buffer->len && !buffer->in_error)
1084  {
1085    bool applied = false;
1086    if (accel.may_have (buffer->cur().codepoint) &&
1087	(buffer->cur().mask & c->lookup_mask) &&
1088	c->check_glyph_property (&buffer->cur(), c->lookup_props))
1089     {
1090       for (unsigned int i = 0; i < subtables.len; i++)
1091         if (subtables[i].apply (c))
1092	 {
1093	   applied = true;
1094	   break;
1095	 }
1096     }
1097
1098    if (applied)
1099      ret = true;
1100    else
1101      buffer->next_glyph ();
1102  }
1103  return ret;
1104}
1105
1106static inline bool
1107apply_backward (OT::hb_apply_context_t *c,
1108	       const hb_ot_layout_lookup_accelerator_t &accel,
1109	       const hb_get_subtables_context_t::array_t &subtables)
1110{
1111  bool ret = false;
1112  hb_buffer_t *buffer = c->buffer;
1113  do
1114  {
1115    if (accel.may_have (buffer->cur().codepoint) &&
1116	(buffer->cur().mask & c->lookup_mask) &&
1117	c->check_glyph_property (&buffer->cur(), c->lookup_props))
1118    {
1119     for (unsigned int i = 0; i < subtables.len; i++)
1120       if (subtables[i].apply (c))
1121       {
1122	 ret = true;
1123	 break;
1124       }
1125    }
1126    /* The reverse lookup doesn't "advance" cursor (for good reason). */
1127    buffer->idx--;
1128
1129  }
1130  while ((int) buffer->idx >= 0);
1131  return ret;
1132}
1133
1134template <typename Proxy>
1135static inline void
1136apply_string (OT::hb_apply_context_t *c,
1137	      const typename Proxy::Lookup &lookup,
1138	      const hb_ot_layout_lookup_accelerator_t &accel)
1139{
1140  hb_buffer_t *buffer = c->buffer;
1141
1142  if (unlikely (!buffer->len || !c->lookup_mask))
1143    return;
1144
1145  c->set_lookup_props (lookup.get_props ());
1146
1147  hb_get_subtables_context_t::array_t subtables;
1148  hb_get_subtables_context_t c_get_subtables (subtables);
1149  lookup.dispatch (&c_get_subtables);
1150
1151  if (likely (!lookup.is_reverse ()))
1152  {
1153    /* in/out forward substitution/positioning */
1154    if (Proxy::table_index == 0)
1155      buffer->clear_output ();
1156    buffer->idx = 0;
1157
1158    bool ret;
1159    ret = apply_forward (c, accel, subtables);
1160    if (ret)
1161    {
1162      if (!Proxy::inplace)
1163	buffer->swap_buffers ();
1164      else
1165	assert (!buffer->has_separate_output ());
1166    }
1167  }
1168  else
1169  {
1170    /* in-place backward substitution/positioning */
1171    if (Proxy::table_index == 0)
1172      buffer->remove_output ();
1173    buffer->idx = buffer->len - 1;
1174
1175    apply_backward (c, accel, subtables);
1176  }
1177}
1178
1179template <typename Proxy>
1180inline void hb_ot_map_t::apply (const Proxy &proxy,
1181				const hb_ot_shape_plan_t *plan,
1182				hb_font_t *font,
1183				hb_buffer_t *buffer) const
1184{
1185  const unsigned int table_index = proxy.table_index;
1186  unsigned int i = 0;
1187  OT::hb_apply_context_t c (table_index, font, buffer);
1188  c.set_recurse_func (Proxy::Lookup::apply_recurse_func);
1189
1190  for (unsigned int stage_index = 0; stage_index < stages[table_index].len; stage_index++) {
1191    const stage_map_t *stage = &stages[table_index][stage_index];
1192    for (; i < stage->last_lookup; i++)
1193    {
1194      unsigned int lookup_index = lookups[table_index][i].index;
1195      if (!buffer->message (font, "start lookup %d", lookup_index)) continue;
1196      c.set_lookup_index (lookup_index);
1197      c.set_lookup_mask (lookups[table_index][i].mask);
1198      c.set_auto_zwj (lookups[table_index][i].auto_zwj);
1199      apply_string<Proxy> (&c,
1200			   proxy.table.get_lookup (lookup_index),
1201			   proxy.accels[lookup_index]);
1202      (void) buffer->message (font, "end lookup %d", lookup_index);
1203    }
1204
1205    if (stage->pause_func)
1206    {
1207      buffer->clear_output ();
1208      stage->pause_func (plan, font, buffer);
1209    }
1210  }
1211}
1212
1213void hb_ot_map_t::substitute (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1214{
1215  GSUBProxy proxy (font->face);
1216  apply (proxy, plan, font, buffer);
1217}
1218
1219void hb_ot_map_t::position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const
1220{
1221  GPOSProxy proxy (font->face);
1222  apply (proxy, plan, font, buffer);
1223}
1224
1225HB_INTERNAL void
1226hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
1227				const OT::SubstLookup &lookup,
1228				const hb_ot_layout_lookup_accelerator_t &accel)
1229{
1230  apply_string<GSUBProxy> (c, lookup, accel);
1231}
1232