hb-ot-layout.cc revision 89ca8eeb83fedde06727d386369a0a39d410f12b
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  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-ot-layout-private.hh"
32
33#include "hb-ot-layout-gdef-table.hh"
34#include "hb-ot-layout-gsub-table.hh"
35#include "hb-ot-layout-gpos-table.hh"
36#include "hb-ot-maxp-table.hh"
37
38#include <stdlib.h>
39#include <string.h>
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->gsub_lookup_count = layout->gsub->get_lookup_count ();
61  layout->gpos_lookup_count = layout->gpos->get_lookup_count ();
62
63  layout->gsub_digests = (hb_set_digest_t *) calloc (layout->gsub->get_lookup_count (), sizeof (hb_set_digest_t));
64  layout->gpos_digests = (hb_set_digest_t *) calloc (layout->gpos->get_lookup_count (), sizeof (hb_set_digest_t));
65
66  if (unlikely ((layout->gsub_lookup_count && !layout->gsub_digests) ||
67		(layout->gpos_lookup_count && !layout->gpos_digests)))
68  {
69    _hb_ot_layout_destroy (layout);
70    return NULL;
71  }
72
73  for (unsigned int i = 0; i < layout->gsub_lookup_count; i++)
74    layout->gsub->add_coverage (&layout->gsub_digests[i], i);
75  for (unsigned int i = 0; i < layout->gpos_lookup_count; i++)
76    layout->gpos->add_coverage (&layout->gpos_digests[i], i);
77
78  return layout;
79}
80
81void
82_hb_ot_layout_destroy (hb_ot_layout_t *layout)
83{
84  hb_blob_destroy (layout->gdef_blob);
85  hb_blob_destroy (layout->gsub_blob);
86  hb_blob_destroy (layout->gpos_blob);
87
88  free (layout->gsub_digests);
89  free (layout->gpos_digests);
90
91  free (layout);
92}
93
94static inline const OT::GDEF&
95_get_gdef (hb_face_t *face)
96{
97  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GDEF);
98  return *hb_ot_layout_from_face (face)->gdef;
99}
100static inline const OT::GSUB&
101_get_gsub (hb_face_t *face)
102{
103  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GSUB);
104  return *hb_ot_layout_from_face (face)->gsub;
105}
106static inline const OT::GPOS&
107_get_gpos (hb_face_t *face)
108{
109  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GPOS);
110  return *hb_ot_layout_from_face (face)->gpos;
111}
112
113
114/*
115 * GDEF
116 */
117
118hb_bool_t
119hb_ot_layout_has_glyph_classes (hb_face_t *face)
120{
121  return _get_gdef (face).has_glyph_classes ();
122}
123
124hb_ot_layout_glyph_class_t
125hb_ot_layout_get_glyph_class (hb_face_t      *face,
126			      hb_codepoint_t  glyph)
127{
128  return (hb_ot_layout_glyph_class_t) _get_gdef (face).get_glyph_class (glyph);
129}
130
131void
132hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
133				  hb_ot_layout_glyph_class_t  klass,
134				  hb_set_t                   *glyphs /* OUT */)
135{
136  return _get_gdef (face).get_glyphs_in_class (klass, glyphs);
137}
138
139unsigned int
140hb_ot_layout_get_attach_points (hb_face_t      *face,
141				hb_codepoint_t  glyph,
142				unsigned int    start_offset,
143				unsigned int   *point_count /* IN/OUT */,
144				unsigned int   *point_array /* OUT */)
145{
146  return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
147}
148
149unsigned int
150hb_ot_layout_get_ligature_carets (hb_font_t      *font,
151				  hb_direction_t  direction,
152				  hb_codepoint_t  glyph,
153				  unsigned int    start_offset,
154				  unsigned int   *caret_count /* IN/OUT */,
155				  int            *caret_array /* OUT */)
156{
157  return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
158}
159
160
161/*
162 * GSUB/GPOS
163 */
164
165static const OT::GSUBGPOS&
166get_gsubgpos_table (hb_face_t *face,
167		    hb_tag_t   table_tag)
168{
169  switch (table_tag) {
170    case HB_OT_TAG_GSUB: return _get_gsub (face);
171    case HB_OT_TAG_GPOS: return _get_gpos (face);
172    default:             return OT::Null(OT::GSUBGPOS);
173  }
174}
175
176
177unsigned int
178hb_ot_layout_table_get_script_tags (hb_face_t    *face,
179				    hb_tag_t      table_tag,
180				    unsigned int  start_offset,
181				    unsigned int *script_count /* IN/OUT */,
182				    hb_tag_t     *script_tags /* OUT */)
183{
184  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
185
186  return g.get_script_tags (start_offset, script_count, script_tags);
187}
188
189hb_bool_t
190hb_ot_layout_table_find_script (hb_face_t    *face,
191				hb_tag_t      table_tag,
192				hb_tag_t      script_tag,
193				unsigned int *script_index)
194{
195  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
196  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
197
198  if (g.find_script_index (script_tag, script_index))
199    return true;
200
201  /* try finding 'DFLT' */
202  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
203    return false;
204
205  /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
206   * including many versions of DejaVu Sans Mono! */
207  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
208    return false;
209
210  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
211  return false;
212}
213
214hb_bool_t
215hb_ot_layout_table_choose_script (hb_face_t      *face,
216				  hb_tag_t        table_tag,
217				  const hb_tag_t *script_tags,
218				  unsigned int   *script_index,
219				  hb_tag_t       *chosen_script)
220{
221  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
222  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
223
224  while (*script_tags)
225  {
226    if (g.find_script_index (*script_tags, script_index)) {
227      if (chosen_script)
228        *chosen_script = *script_tags;
229      return true;
230    }
231    script_tags++;
232  }
233
234  /* try finding 'DFLT' */
235  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
236    if (chosen_script)
237      *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
238    return false;
239  }
240
241  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
242  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
243    if (chosen_script)
244      *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
245    return false;
246  }
247
248  /* try with 'latn'; some old fonts put their features there even though
249     they're really trying to support Thai, for example :( */
250#define HB_OT_TAG_LATIN_SCRIPT		HB_TAG ('l', 'a', 't', 'n')
251  if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
252    if (chosen_script)
253      *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
254    return false;
255  }
256
257  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
258  if (chosen_script)
259    *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
260  return false;
261}
262
263unsigned int
264hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
265				     hb_tag_t      table_tag,
266				     unsigned int  start_offset,
267				     unsigned int *feature_count /* IN/OUT */,
268				     hb_tag_t     *feature_tags /* OUT */)
269{
270  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
271
272  return g.get_feature_tags (start_offset, feature_count, feature_tags);
273}
274
275
276unsigned int
277hb_ot_layout_script_get_language_tags (hb_face_t    *face,
278				       hb_tag_t      table_tag,
279				       unsigned int  script_index,
280				       unsigned int  start_offset,
281				       unsigned int *language_count /* IN/OUT */,
282				       hb_tag_t     *language_tags /* OUT */)
283{
284  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
285
286  return s.get_lang_sys_tags (start_offset, language_count, language_tags);
287}
288
289hb_bool_t
290hb_ot_layout_script_find_language (hb_face_t    *face,
291				   hb_tag_t      table_tag,
292				   unsigned int  script_index,
293				   hb_tag_t      language_tag,
294				   unsigned int *language_index)
295{
296  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
297  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
298
299  if (s.find_lang_sys_index (language_tag, language_index))
300    return true;
301
302  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
303  if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
304    return false;
305
306  if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
307  return false;
308}
309
310hb_bool_t
311hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
312						  hb_tag_t      table_tag,
313						  unsigned int  script_index,
314						  unsigned int  language_index,
315						  unsigned int *feature_index)
316{
317  const OT::LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);
318
319  if (feature_index) *feature_index = l.get_required_feature_index ();
320
321  return l.has_required_feature ();
322}
323
324unsigned int
325hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
326					   hb_tag_t      table_tag,
327					   unsigned int  script_index,
328					   unsigned int  language_index,
329					   unsigned int  start_offset,
330					   unsigned int *feature_count /* IN/OUT */,
331					   unsigned int *feature_indexes /* OUT */)
332{
333  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
334  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
335
336  return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
337}
338
339unsigned int
340hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
341					hb_tag_t      table_tag,
342					unsigned int  script_index,
343					unsigned int  language_index,
344					unsigned int  start_offset,
345					unsigned int *feature_count /* IN/OUT */,
346					hb_tag_t     *feature_tags /* OUT */)
347{
348  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
349  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
350
351  ASSERT_STATIC (sizeof (unsigned int) == sizeof (hb_tag_t));
352  unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
353
354  if (feature_tags) {
355    unsigned int count = *feature_count;
356    for (unsigned int i = 0; i < count; i++)
357      feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
358  }
359
360  return ret;
361}
362
363
364hb_bool_t
365hb_ot_layout_language_find_feature (hb_face_t    *face,
366				    hb_tag_t      table_tag,
367				    unsigned int  script_index,
368				    unsigned int  language_index,
369				    hb_tag_t      feature_tag,
370				    unsigned int *feature_index)
371{
372  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
373  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
374  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
375
376  unsigned int num_features = l.get_feature_count ();
377  for (unsigned int i = 0; i < num_features; i++) {
378    unsigned int f_index = l.get_feature_index (i);
379
380    if (feature_tag == g.get_feature_tag (f_index)) {
381      if (feature_index) *feature_index = f_index;
382      return true;
383    }
384  }
385
386  if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
387  return false;
388}
389
390unsigned int
391hb_ot_layout_feature_get_lookups (hb_face_t    *face,
392				  hb_tag_t      table_tag,
393				  unsigned int  feature_index,
394				  unsigned int  start_offset,
395				  unsigned int *lookup_count /* IN/OUT */,
396				  unsigned int *lookup_indexes /* OUT */)
397{
398  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
399  const OT::Feature &f = g.get_feature (feature_index);
400
401  return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
402}
403
404
405/*
406 * OT::GSUB
407 */
408
409hb_bool_t
410hb_ot_layout_has_substitution (hb_face_t *face)
411{
412  return &_get_gsub (face) != &OT::Null(OT::GSUB);
413}
414
415hb_bool_t
416hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
417				      unsigned int          lookup_index,
418				      const hb_codepoint_t *glyphs,
419				      unsigned int          glyphs_length,
420				      hb_bool_t             zero_context)
421{
422  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return false;
423  return hb_ot_layout_lookup_would_substitute_fast (face, lookup_index, glyphs, glyphs_length, zero_context);
424}
425
426hb_bool_t
427hb_ot_layout_lookup_would_substitute_fast (hb_face_t            *face,
428					   unsigned int          lookup_index,
429					   const hb_codepoint_t *glyphs,
430					   unsigned int          glyphs_length,
431					   hb_bool_t             zero_context)
432{
433  if (unlikely (lookup_index >= hb_ot_layout_from_face (face)->gsub_lookup_count)) return false;
434  OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, zero_context);
435
436  const OT::SubstLookup& l = hb_ot_layout_from_face (face)->gsub->get_lookup (lookup_index);
437
438  return l.would_apply (&c, &hb_ot_layout_from_face (face)->gsub_digests[lookup_index]);
439}
440
441void
442hb_ot_layout_substitute_start (hb_font_t *font, hb_buffer_t *buffer)
443{
444  OT::GSUB::substitute_start (font, buffer);
445}
446
447hb_bool_t
448hb_ot_layout_substitute_lookup (hb_font_t    *font,
449				hb_buffer_t  *buffer,
450				unsigned int  lookup_index,
451				hb_mask_t     mask)
452{
453  if (unlikely (lookup_index >= hb_ot_layout_from_face (font->face)->gsub_lookup_count)) return false;
454
455  OT::hb_apply_context_t c (font, buffer, mask);
456
457  const OT::SubstLookup& l = hb_ot_layout_from_face (font->face)->gsub->get_lookup (lookup_index);
458
459  return l.apply_string (&c, &hb_ot_layout_from_face (font->face)->gsub_digests[lookup_index]);
460}
461
462void
463hb_ot_layout_substitute_finish (hb_font_t *font, hb_buffer_t *buffer)
464{
465  OT::GSUB::substitute_finish (font, buffer);
466}
467
468void
469hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
470				        unsigned int  lookup_index,
471				        hb_set_t     *glyphs)
472{
473  OT::hb_closure_context_t c (face, glyphs);
474  _get_gsub (face).closure_lookup (&c, lookup_index);
475}
476
477/*
478 * OT::GPOS
479 */
480
481hb_bool_t
482hb_ot_layout_has_positioning (hb_face_t *face)
483{
484  return &_get_gpos (face) != &OT::Null(OT::GPOS);
485}
486
487void
488hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
489{
490  OT::GPOS::position_start (font, buffer);
491}
492
493hb_bool_t
494hb_ot_layout_position_lookup (hb_font_t    *font,
495			      hb_buffer_t  *buffer,
496			      unsigned int  lookup_index,
497			      hb_mask_t     mask)
498{
499  if (unlikely (lookup_index >= hb_ot_layout_from_face (font->face)->gpos_lookup_count)) return false;
500
501  OT::hb_apply_context_t c (font, buffer, mask);
502
503  const OT::PosLookup& l = hb_ot_layout_from_face (font->face)->gpos->get_lookup (lookup_index);
504
505  return l.apply_string (&c, &hb_ot_layout_from_face (font->face)->gpos_digests[lookup_index]);
506}
507
508void
509hb_ot_layout_position_finish (hb_font_t *font, hb_buffer_t *buffer, hb_bool_t zero_width_attached_marks)
510{
511  OT::GPOS::position_finish (font, buffer, zero_width_attached_marks);
512}
513