hb-ot-layout.cc revision c47a31fb4793b825f4be57e9cb1b10db352b9512 
1/*
2 * Copyright © 1998-2004  David Turner and Werner Lemberg
3 * Copyright © 2006  Behdad Esfahbod
4 * Copyright © 2007,2008,2009  Red Hat, Inc.
5 *
6 *  This is part of HarfBuzz, a text shaping library.
7 *
8 * Permission is hereby granted, without written agreement and without
9 * license or royalty fees, to use, copy, modify, and distribute this
10 * software and its documentation for any purpose, provided that the
11 * above copyright notice and the following two paragraphs appear in
12 * all copies of this software.
13 *
14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * DAMAGE.
19 *
20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 *
26 * Red Hat Author(s): Behdad Esfahbod
27 */
28
29#define HB_OT_LAYOUT_CC
30
31#include "hb-ot-layout-private.hh"
32
33#include "hb-ot-layout-gdef-private.hh"
34#include "hb-ot-layout-gsub-private.hh"
35#include "hb-ot-layout-gpos-private.hh"
36#include "hb-ot-head-private.hh"
37#include "hb-ot-maxp-private.hh"
38
39
40#include <stdlib.h>
41#include <string.h>
42
43HB_BEGIN_DECLS
44
45
46hb_ot_layout_t *
47_hb_ot_layout_create (hb_face_t *face)
48{
49  /* TODO Remove this object altogether */
50  hb_ot_layout_t *layout = (hb_ot_layout_t *) calloc (1, sizeof (hb_ot_layout_t));
51
52  layout->gdef_blob = Sanitizer<GDEF>::sanitize (hb_face_reference_table (face, HB_OT_TAG_GDEF));
53  layout->gdef = Sanitizer<GDEF>::lock_instance (layout->gdef_blob);
54
55  layout->gsub_blob = Sanitizer<GSUB>::sanitize (hb_face_reference_table (face, HB_OT_TAG_GSUB));
56  layout->gsub = Sanitizer<GSUB>::lock_instance (layout->gsub_blob);
57
58  layout->gpos_blob = Sanitizer<GPOS>::sanitize (hb_face_reference_table (face, HB_OT_TAG_GPOS));
59  layout->gpos = Sanitizer<GPOS>::lock_instance (layout->gpos_blob);
60
61  layout->head_blob = Sanitizer<head>::sanitize (hb_face_reference_table (face, HB_OT_TAG_head));
62  layout->head = Sanitizer<head>::lock_instance (layout->head_blob);
63
64  return layout;
65}
66
67void
68_hb_ot_layout_destroy (hb_ot_layout_t *layout)
69{
70  hb_blob_destroy (layout->gdef_blob);
71  hb_blob_destroy (layout->gsub_blob);
72  hb_blob_destroy (layout->gpos_blob);
73  hb_blob_destroy (layout->head_blob);
74
75  free (layout);
76}
77
78static inline const GDEF&
79_get_gdef (hb_face_t *face)
80{
81  return likely (face->ot_layout && face->ot_layout->gdef) ? *face->ot_layout->gdef : Null(GDEF);
82}
83static inline const GSUB&
84_get_gsub (hb_face_t *face)
85{
86  return likely (face->ot_layout && face->ot_layout->gsub) ? *face->ot_layout->gsub : Null(GSUB);
87}
88static inline const GPOS&
89_get_gpos (hb_face_t *face)
90{
91  return likely (face->ot_layout && face->ot_layout->gpos) ? *face->ot_layout->gpos : Null(GPOS);
92}
93static inline const head&
94_get_head (hb_face_t *face)
95{
96  return likely (face->ot_layout && face->ot_layout->head) ? *face->ot_layout->head : Null(head);
97}
98
99
100/*
101 * GDEF
102 */
103
104hb_bool_t
105hb_ot_layout_has_glyph_classes (hb_face_t *face)
106{
107  return _get_gdef (face).has_glyph_classes ();
108}
109
110unsigned int
111_hb_ot_layout_get_glyph_property (hb_face_t       *face,
112				  hb_glyph_info_t *info)
113{
114  if (!info->props_cache())
115  {
116    const GDEF &gdef = _get_gdef (face);
117    info->props_cache() = gdef.get_glyph_props (info->codepoint);
118  }
119
120  return info->props_cache();
121}
122
123static hb_bool_t
124_hb_ot_layout_match_properties (hb_face_t      *face,
125				hb_codepoint_t  codepoint,
126				unsigned int    glyph_props,
127				unsigned int    lookup_props)
128{
129  /* Not covered, if, for example, glyph class is ligature and
130   * lookup_props includes LookupFlags::IgnoreLigatures
131   */
132  if (glyph_props & lookup_props & LookupFlag::IgnoreFlags)
133    return false;
134
135  if (glyph_props & HB_OT_LAYOUT_GLYPH_CLASS_MARK)
136  {
137    /* If using mark filtering sets, the high short of
138     * lookup_props has the set index.
139     */
140    if (lookup_props & LookupFlag::UseMarkFilteringSet)
141      return _get_gdef (face).mark_set_covers (lookup_props >> 16, codepoint);
142
143    /* The second byte of lookup_props has the meaning
144     * "ignore marks of attachment type different than
145     * the attachment type specified."
146     */
147    if (lookup_props & LookupFlag::MarkAttachmentType && glyph_props & LookupFlag::MarkAttachmentType)
148      return (lookup_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType);
149  }
150
151  return true;
152}
153
154hb_bool_t
155_hb_ot_layout_check_glyph_property (hb_face_t    *face,
156				    hb_glyph_info_t *ginfo,
157				    unsigned int  lookup_props,
158				    unsigned int *property_out)
159{
160  unsigned int property;
161
162  property = _hb_ot_layout_get_glyph_property (face, ginfo);
163  (void) (property_out && (*property_out = property));
164
165  return _hb_ot_layout_match_properties (face, ginfo->codepoint, property, lookup_props);
166}
167
168hb_bool_t
169_hb_ot_layout_skip_mark (hb_face_t    *face,
170			 hb_glyph_info_t *ginfo,
171			 unsigned int  lookup_props,
172			 unsigned int *property_out)
173{
174  unsigned int property;
175
176  property = _hb_ot_layout_get_glyph_property (face, ginfo);
177  (void) (property_out && (*property_out = property));
178
179  /* If it's a mark, skip it we don't accept it. */
180  if (unlikely (property & HB_OT_LAYOUT_GLYPH_CLASS_MARK))
181    return !_hb_ot_layout_match_properties (face, ginfo->codepoint, property, lookup_props);
182
183  /* If not a mark, don't skip. */
184  return false;
185}
186
187
188
189unsigned int
190hb_ot_layout_get_attach_points (hb_face_t      *face,
191				hb_codepoint_t  glyph,
192				unsigned int    start_offset,
193				unsigned int   *point_count /* IN/OUT */,
194				unsigned int   *point_array /* OUT */)
195{
196  return _get_gdef (face).get_attach_points (glyph, start_offset, point_count, point_array);
197}
198
199unsigned int
200hb_ot_layout_get_ligature_carets (hb_font_t      *font,
201				  hb_direction_t  direction,
202				  hb_codepoint_t  glyph,
203				  unsigned int    start_offset,
204				  unsigned int   *caret_count /* IN/OUT */,
205				  int            *caret_array /* OUT */)
206{
207  return _get_gdef (font->face).get_lig_carets (font, direction, glyph, start_offset, caret_count, caret_array);
208}
209
210/*
211 * GSUB/GPOS
212 */
213
214static const GSUBGPOS&
215get_gsubgpos_table (hb_face_t *face,
216		    hb_tag_t   table_tag)
217{
218  switch (table_tag) {
219    case HB_OT_TAG_GSUB: return _get_gsub (face);
220    case HB_OT_TAG_GPOS: return _get_gpos (face);
221    default:             return Null(GSUBGPOS);
222  }
223}
224
225
226unsigned int
227hb_ot_layout_table_get_script_tags (hb_face_t    *face,
228				    hb_tag_t      table_tag,
229				    unsigned int  start_offset,
230				    unsigned int *script_count /* IN/OUT */,
231				    hb_tag_t     *script_tags /* OUT */)
232{
233  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
234
235  return g.get_script_tags (start_offset, script_count, script_tags);
236}
237
238hb_bool_t
239hb_ot_layout_table_find_script (hb_face_t    *face,
240				hb_tag_t      table_tag,
241				hb_tag_t      script_tag,
242				unsigned int *script_index)
243{
244  ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
245  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
246
247  if (g.find_script_index (script_tag, script_index))
248    return TRUE;
249
250  /* try finding 'DFLT' */
251  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index))
252    return FALSE;
253
254  /* try with 'dflt'; MS site has had typos and many fonts use it now :(.
255   * including many versions of DejaVu Sans Mono! */
256  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index))
257    return FALSE;
258
259  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
260  return FALSE;
261}
262
263hb_bool_t
264hb_ot_layout_table_choose_script (hb_face_t      *face,
265				  hb_tag_t        table_tag,
266				  const hb_tag_t *script_tags,
267				  unsigned int   *script_index,
268				  hb_tag_t       *chosen_script)
269{
270  ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_SCRIPT_INDEX);
271  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
272
273  while (*script_tags)
274  {
275    if (g.find_script_index (*script_tags, script_index)) {
276      if (chosen_script)
277        *chosen_script = *script_tags;
278      return TRUE;
279    }
280    script_tags++;
281  }
282
283  /* try finding 'DFLT' */
284  if (g.find_script_index (HB_OT_TAG_DEFAULT_SCRIPT, script_index)) {
285    if (chosen_script)
286      *chosen_script = HB_OT_TAG_DEFAULT_SCRIPT;
287    return FALSE;
288  }
289
290  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
291  if (g.find_script_index (HB_OT_TAG_DEFAULT_LANGUAGE, script_index)) {
292    if (chosen_script)
293      *chosen_script = HB_OT_TAG_DEFAULT_LANGUAGE;
294    return FALSE;
295  }
296
297  if (script_index) *script_index = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
298  if (chosen_script)
299    *chosen_script = HB_OT_LAYOUT_NO_SCRIPT_INDEX;
300  return FALSE;
301}
302
303unsigned int
304hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
305				     hb_tag_t      table_tag,
306				     unsigned int  start_offset,
307				     unsigned int *feature_count /* IN/OUT */,
308				     hb_tag_t     *feature_tags /* OUT */)
309{
310  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
311
312  return g.get_feature_tags (start_offset, feature_count, feature_tags);
313}
314
315
316unsigned int
317hb_ot_layout_script_get_language_tags (hb_face_t    *face,
318				       hb_tag_t      table_tag,
319				       unsigned int  script_index,
320				       unsigned int  start_offset,
321				       unsigned int *language_count /* IN/OUT */,
322				       hb_tag_t     *language_tags /* OUT */)
323{
324  const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
325
326  return s.get_lang_sys_tags (start_offset, language_count, language_tags);
327}
328
329hb_bool_t
330hb_ot_layout_script_find_language (hb_face_t    *face,
331				   hb_tag_t      table_tag,
332				   unsigned int  script_index,
333				   hb_tag_t      language_tag,
334				   unsigned int *language_index)
335{
336  ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX);
337  const Script &s = get_gsubgpos_table (face, table_tag).get_script (script_index);
338
339  if (s.find_lang_sys_index (language_tag, language_index))
340    return TRUE;
341
342  /* try with 'dflt'; MS site has had typos and many fonts use it now :( */
343  if (s.find_lang_sys_index (HB_OT_TAG_DEFAULT_LANGUAGE, language_index))
344    return FALSE;
345
346  if (language_index) *language_index = HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX;
347  return FALSE;
348}
349
350hb_bool_t
351hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
352						  hb_tag_t      table_tag,
353						  unsigned int  script_index,
354						  unsigned int  language_index,
355						  unsigned int *feature_index)
356{
357  const LangSys &l = get_gsubgpos_table (face, table_tag).get_script (script_index).get_lang_sys (language_index);
358
359  if (feature_index) *feature_index = l.get_required_feature_index ();
360
361  return l.has_required_feature ();
362}
363
364unsigned int
365hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
366					   hb_tag_t      table_tag,
367					   unsigned int  script_index,
368					   unsigned int  language_index,
369					   unsigned int  start_offset,
370					   unsigned int *feature_count /* IN/OUT */,
371					   unsigned int *feature_indexes /* OUT */)
372{
373  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
374  const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
375
376  return l.get_feature_indexes (start_offset, feature_count, feature_indexes);
377}
378
379unsigned int
380hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
381					hb_tag_t      table_tag,
382					unsigned int  script_index,
383					unsigned int  language_index,
384					unsigned int  start_offset,
385					unsigned int *feature_count /* IN/OUT */,
386					hb_tag_t     *feature_tags /* OUT */)
387{
388  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
389  const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
390
391  ASSERT_STATIC (sizeof (unsigned int) == sizeof (hb_tag_t));
392  unsigned int ret = l.get_feature_indexes (start_offset, feature_count, (unsigned int *) feature_tags);
393
394  if (feature_tags) {
395    unsigned int count = *feature_count;
396    for (unsigned int i = 0; i < count; i++)
397      feature_tags[i] = g.get_feature_tag ((unsigned int) feature_tags[i]);
398  }
399
400  return ret;
401}
402
403
404hb_bool_t
405hb_ot_layout_language_find_feature (hb_face_t    *face,
406				    hb_tag_t      table_tag,
407				    unsigned int  script_index,
408				    unsigned int  language_index,
409				    hb_tag_t      feature_tag,
410				    unsigned int *feature_index)
411{
412  ASSERT_STATIC (Index::NOT_FOUND_INDEX == HB_OT_LAYOUT_NO_FEATURE_INDEX);
413  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
414  const LangSys &l = g.get_script (script_index).get_lang_sys (language_index);
415
416  unsigned int num_features = l.get_feature_count ();
417  for (unsigned int i = 0; i < num_features; i++) {
418    unsigned int f_index = l.get_feature_index (i);
419
420    if (feature_tag == g.get_feature_tag (f_index)) {
421      if (feature_index) *feature_index = f_index;
422      return TRUE;
423    }
424  }
425
426  if (feature_index) *feature_index = HB_OT_LAYOUT_NO_FEATURE_INDEX;
427  return FALSE;
428}
429
430unsigned int
431hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
432					 hb_tag_t      table_tag,
433					 unsigned int  feature_index,
434					 unsigned int  start_offset,
435					 unsigned int *lookup_count /* IN/OUT */,
436					 unsigned int *lookup_indexes /* OUT */)
437{
438  const GSUBGPOS &g = get_gsubgpos_table (face, table_tag);
439  const Feature &f = g.get_feature (feature_index);
440
441  return f.get_lookup_indexes (start_offset, lookup_count, lookup_indexes);
442}
443
444
445/*
446 * GSUB
447 */
448
449hb_bool_t
450hb_ot_layout_has_substitution (hb_face_t *face)
451{
452  return &_get_gsub (face) != &Null(GSUB);
453}
454
455void
456hb_ot_layout_substitute_start (hb_buffer_t  *buffer)
457{
458  GSUB::substitute_start (buffer);
459}
460
461hb_bool_t
462hb_ot_layout_substitute_lookup (hb_face_t    *face,
463				hb_buffer_t  *buffer,
464				unsigned int  lookup_index,
465				hb_mask_t     mask)
466{
467  return _get_gsub (face).substitute_lookup (face, buffer, lookup_index, mask);
468}
469
470void
471hb_ot_layout_substitute_finish (hb_buffer_t  *buffer HB_UNUSED)
472{
473  GSUB::substitute_finish (buffer);
474}
475
476
477/*
478 * GPOS
479 */
480
481hb_bool_t
482hb_ot_layout_has_positioning (hb_face_t *face)
483{
484  return &_get_gpos (face) != &Null(GPOS);
485}
486
487void
488hb_ot_layout_position_start (hb_buffer_t  *buffer)
489{
490  GPOS::position_start (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  return _get_gpos (font->face).position_lookup (font, buffer, lookup_index, mask);
500}
501
502void
503hb_ot_layout_position_finish (hb_buffer_t  *buffer)
504{
505  GPOS::position_finish (buffer);
506}
507
508
509/*
510 * head
511 */
512
513unsigned int
514_hb_ot_layout_get_upem (hb_face_t *face)
515{
516  return _get_head (face).get_upem ();
517}
518
519
520HB_END_DECLS
521