hb-ot-layout.cc revision a5ddd9e31cd7906c4b559aa5b2fafdae4b9c8935 
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
124
125unsigned int
126hb_ot_layout_get_attach_points (hb_face_t      *face,
127				hb_codepoint_t  glyph,
128				unsigned int    start_offset,
129				unsigned int   *point_count /* IN/OUT */,
130				unsigned int   *point_array /* OUT */)
131{
132  return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
133}
134
135unsigned int
136hb_ot_layout_get_ligature_carets (hb_font_t      *font,
137				  hb_direction_t  direction,
138				  hb_codepoint_t  glyph,
139				  unsigned int    start_offset,
140				  unsigned int   *caret_count /* IN/OUT */,
141				  int            *caret_array /* OUT */)
142{
143  return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
144}
145
146
147/*
148 * GSUB/GPOS
149 */
150
151static const OT::GSUBGPOS&
152get_gsubgpos_table (hb_face_t *face,
153		    hb_tag_t   table_tag)
154{
155  switch (table_tag) {
156    case HB_OT_TAG_GSUB: return _get_gsub (face);
157    case HB_OT_TAG_GPOS: return _get_gpos (face);
158    default:             return OT::Null(OT::GSUBGPOS);
159  }
160}
161
162
163unsigned int
164hb_ot_layout_table_get_script_tags (hb_face_t    *face,
165				    hb_tag_t      table_tag,
166				    unsigned int  start_offset,
167				    unsigned int *script_count /* IN/OUT */,
168				    hb_tag_t     *script_tags /* OUT */)
169{
170  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
171
172  return g.get_script_tags (start_offset, script_count, script_tags);
173}
174
175hb_bool_t
176hb_ot_layout_table_find_script (hb_face_t    *face,
177				hb_tag_t      table_tag,
178				hb_tag_t      script_tag,
179				unsigned int *script_index)
180{
181  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
182  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
183
184  if (g.find_script_index (script_tag, script_index))
185    return true;
186
187  /* try finding 'DFLT' */
188  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
189    return false;
190
191  /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
192   * including many versions of DejaVu Sans Mono! */
193  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
194    return false;
195
196  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
197  return false;
198}
199
200hb_bool_t
201hb_ot_layout_table_choose_script (hb_face_t      *face,
202				  hb_tag_t        table_tag,
203				  const hb_tag_t *script_tags,
204				  unsigned int   *script_index,
205				  hb_tag_t       *chosen_script)
206{
207  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
208  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
209
210  while (*script_tags)
211  {
212    if (g.find_script_index (*script_tags, script_index)) {
213      if (chosen_script)
214        *chosen_script = *script_tags;
215      return true;
216    }
217    script_tags++;
218  }
219
220  /* try finding 'DFLT' */
221  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
222    if (chosen_script)
223      *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
224    return false;
225  }
226
227  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
228  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
229    if (chosen_script)
230      *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
231    return false;
232  }
233
234  /* try with 'latn'; some old fonts put their features there even though
235     they're really trying to support Thai, for example :( */
236#define HB_OT_TAG_LATIN_SCRIPT		HB_TAG ('l', 'a', 't', 'n')
237  if (g.find_script_index (HB_OT_TAG_LATIN_SCRIPT, script_index)) {
238    if (chosen_script)
239      *chosen_script = HB_OT_TAG_LATIN_SCRIPT;
240    return false;
241  }
242
243  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
244  if (chosen_script)
245    *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
246  return false;
247}
248
249unsigned int
250hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
251				     hb_tag_t      table_tag,
252				     unsigned int  start_offset,
253				     unsigned int *feature_count /* IN/OUT */,
254				     hb_tag_t     *feature_tags /* OUT */)
255{
256  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
257
258  return g.get_feature_tags (start_offset, feature_count, feature_tags);
259}
260
261
262unsigned int
263hb_ot_layout_script_get_language_tags (hb_face_t    *face,
264				       hb_tag_t      table_tag,
265				       unsigned int  script_index,
266				       unsigned int  start_offset,
267				       unsigned int *language_count /* IN/OUT */,
268				       hb_tag_t     *language_tags /* OUT */)
269{
270  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
271
272  return s.get_lang_sys_tags (start_offset, language_count, language_tags);
273}
274
275hb_bool_t
276hb_ot_layout_script_find_language (hb_face_t    *face,
277				   hb_tag_t      table_tag,
278				   unsigned int  script_index,
279				   hb_tag_t      language_tag,
280				   unsigned int *language_index)
281{
282  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
283  const OT::Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
284
285  if (s.find_lang_sys_index (language_tag, language_index))
286    return true;
287
288  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
289  if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
290    return false;
291
292  if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
293  return false;
294}
295
296hb_bool_t
297hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
298						  hb_tag_t      table_tag,
299						  unsigned int  script_index,
300						  unsigned int  language_index,
301						  unsigned int *feature_index)
302{
303  const OT::LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);
304
305  if (feature_index) *feature_index = l.get_required_feature_index ();
306
307  return l.has_required_feature ();
308}
309
310unsigned int
311hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
312					   hb_tag_t      table_tag,
313					   unsigned int  script_index,
314					   unsigned int  language_index,
315					   unsigned int  start_offset,
316					   unsigned int *feature_count /* IN/OUT */,
317					   unsigned int *feature_indexes /* OUT */)
318{
319  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
320  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
321
322  return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
323}
324
325unsigned int
326hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
327					hb_tag_t      table_tag,
328					unsigned int  script_index,
329					unsigned int  language_index,
330					unsigned int  start_offset,
331					unsigned int *feature_count /* IN/OUT */,
332					hb_tag_t     *feature_tags /* OUT */)
333{
334  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
335  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
336
337  ASSERT_STATIC (sizeof (unsigned int) == sizeof (hb_tag_t));
338  unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
339
340  if (feature_tags) {
341    unsigned int count = *feature_count;
342    for (unsigned int i = 0; i < count; i++)
343      feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
344  }
345
346  return ret;
347}
348
349
350hb_bool_t
351hb_ot_layout_language_find_feature (hb_face_t    *face,
352				    hb_tag_t      table_tag,
353				    unsigned int  script_index,
354				    unsigned int  language_index,
355				    hb_tag_t      feature_tag,
356				    unsigned int *feature_index)
357{
358  ASSERT_STATIC (OT::Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
359  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
360  const OT::LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
361
362  unsigned int num_features = l.get_feature_count ();
363  for (unsigned int i = 0; i < num_features; i++) {
364    unsigned int f_index = l.get_feature_index (i);
365
366    if (feature_tag == g.get_feature_tag (f_index)) {
367      if (feature_index) *feature_index = f_index;
368      return true;
369    }
370  }
371
372  if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
373  return false;
374}
375
376unsigned int
377hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
378					 hb_tag_t      table_tag,
379					 unsigned int  feature_index,
380					 unsigned int  start_offset,
381					 unsigned int *lookup_count /* IN/OUT */,
382					 unsigned int *lookup_indexes /* OUT */)
383{
384  const OT::GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
385  const OT::Feature &f = g.get_feature (feature_index);
386
387  return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
388}
389
390
391/*
392 * OT::GSUB
393 */
394
395hb_bool_t
396hb_ot_layout_has_substitution (hb_face_t *face)
397{
398  return &_get_gsub (face) != &OT::Null(OT::GSUB);
399}
400
401hb_bool_t
402hb_ot_layout_would_substitute_lookup (hb_face_t            *face,
403				      unsigned int          lookup_index,
404				      const hb_codepoint_t *glyphs,
405				      unsigned int          glyphs_length,
406				      hb_bool_t             zero_context)
407{
408  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return false;
409  return hb_ot_layout_would_substitute_lookup_fast (face, lookup_index, glyphs, glyphs_length, zero_context);
410}
411
412hb_bool_t
413hb_ot_layout_would_substitute_lookup_fast (hb_face_t            *face,
414					   unsigned int          lookup_index,
415					   const hb_codepoint_t *glyphs,
416					   unsigned int          glyphs_length,
417					   hb_bool_t             zero_context)
418{
419  if (unlikely (lookup_index >= hb_ot_layout_from_face (face)->gsub_lookup_count)) return false;
420  OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, zero_context, hb_ot_layout_from_face (face)->gsub_digests[lookup_index]);
421  return hb_ot_layout_from_face (face)->gsub->would_substitute_lookup (&c, lookup_index);
422}
423
424void
425hb_ot_layout_substitute_start (hb_font_t *font, hb_buffer_t *buffer)
426{
427  OT::GSUB::substitute_start (font, buffer);
428}
429
430hb_bool_t
431hb_ot_layout_substitute_lookup (hb_font_t    *font,
432				hb_buffer_t  *buffer,
433				unsigned int  lookup_index,
434				hb_mask_t     mask)
435{
436  if (unlikely (lookup_index >= hb_ot_layout_from_face (font->face)->gsub_lookup_count)) return false;
437  OT::hb_apply_context_t c (font, buffer, mask, hb_ot_layout_from_face (font->face)->gsub_digests[lookup_index]);
438  return hb_ot_layout_from_face (font->face)->gsub->substitute_lookup (&c, lookup_index);
439}
440
441void
442hb_ot_layout_substitute_finish (hb_font_t *font, hb_buffer_t *buffer)
443{
444  OT::GSUB::substitute_finish (font, buffer);
445}
446
447void
448hb_ot_layout_substitute_closure_lookup (hb_face_t    *face,
449				        unsigned int  lookup_index,
450				        hb_set_t     *glyphs)
451{
452  OT::hb_closure_context_t c (face, glyphs);
453  _get_gsub (face).closure_lookup (&c, lookup_index);
454}
455
456/*
457 * OT::GPOS
458 */
459
460hb_bool_t
461hb_ot_layout_has_positioning (hb_face_t *face)
462{
463  return &_get_gpos (face) != &OT::Null(OT::GPOS);
464}
465
466void
467hb_ot_layout_position_start (hb_font_t *font, hb_buffer_t *buffer)
468{
469  OT::GPOS::position_start (font, buffer);
470}
471
472hb_bool_t
473hb_ot_layout_position_lookup (hb_font_t    *font,
474			      hb_buffer_t  *buffer,
475			      unsigned int  lookup_index,
476			      hb_mask_t     mask)
477{
478  if (unlikely (lookup_index >= hb_ot_layout_from_face (font->face)->gpos_lookup_count)) return false;
479  OT::hb_apply_context_t c (font, buffer, mask, hb_ot_layout_from_face (font->face)->gpos_digests[lookup_index]);
480  return hb_ot_layout_from_face (font->face)->gpos->position_lookup (&c, lookup_index);
481}
482
483void
484hb_ot_layout_position_finish (hb_font_t *font, hb_buffer_t *buffer, hb_bool_t zero_width_attached_marks)
485{
486  OT::GPOS::position_finish (font, buffer, zero_width_attached_marks);
487}
488