1/*
2 * Copyright © 2007,2008,2009,2010  Red Hat, Inc.
3 * Copyright © 2010,2012,2013  Google, Inc.
4 *
5 *  This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
27 */
28
29#ifndef HB_OT_LAYOUT_GSUB_TABLE_HH
30#define HB_OT_LAYOUT_GSUB_TABLE_HH
31
32#include "hb-ot-layout-gsubgpos-private.hh"
33
34
35namespace OT {
36
37
38struct SingleSubstFormat1
39{
40  inline void closure (hb_closure_context_t *c) const
41  {
42    TRACE_CLOSURE (this);
43    Coverage::Iter iter;
44    for (iter.init (this+coverage); iter.more (); iter.next ()) {
45      hb_codepoint_t glyph_id = iter.get_glyph ();
46      if (c->glyphs->has (glyph_id))
47	c->glyphs->add ((glyph_id + deltaGlyphID) & 0xFFFFu);
48    }
49  }
50
51  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
52  {
53    TRACE_COLLECT_GLYPHS (this);
54    Coverage::Iter iter;
55    for (iter.init (this+coverage); iter.more (); iter.next ()) {
56      hb_codepoint_t glyph_id = iter.get_glyph ();
57      c->input->add (glyph_id);
58      c->output->add ((glyph_id + deltaGlyphID) & 0xFFFFu);
59    }
60  }
61
62  inline const Coverage &get_coverage (void) const
63  {
64    return this+coverage;
65  }
66
67  inline bool would_apply (hb_would_apply_context_t *c) const
68  {
69    TRACE_WOULD_APPLY (this);
70    return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
71  }
72
73  inline bool apply (hb_apply_context_t *c) const
74  {
75    TRACE_APPLY (this);
76    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
77    unsigned int index = (this+coverage).get_coverage (glyph_id);
78    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
79
80    /* According to the Adobe Annotated OpenType Suite, result is always
81     * limited to 16bit. */
82    glyph_id = (glyph_id + deltaGlyphID) & 0xFFFFu;
83    c->replace_glyph (glyph_id);
84
85    return TRACE_RETURN (true);
86  }
87
88  inline bool serialize (hb_serialize_context_t *c,
89			 Supplier<GlyphID> &glyphs,
90			 unsigned int num_glyphs,
91			 int delta)
92  {
93    TRACE_SERIALIZE (this);
94    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
95    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
96    deltaGlyphID.set (delta); /* TODO(serilaize) overflow? */
97    return TRACE_RETURN (true);
98  }
99
100  inline bool sanitize (hb_sanitize_context_t *c) {
101    TRACE_SANITIZE (this);
102    return TRACE_RETURN (coverage.sanitize (c, this) && deltaGlyphID.sanitize (c));
103  }
104
105  protected:
106  USHORT	format;			/* Format identifier--format = 1 */
107  OffsetTo<Coverage>
108		coverage;		/* Offset to Coverage table--from
109					 * beginning of Substitution table */
110  SHORT		deltaGlyphID;		/* Add to original GlyphID to get
111					 * substitute GlyphID */
112  public:
113  DEFINE_SIZE_STATIC (6);
114};
115
116struct SingleSubstFormat2
117{
118  inline void closure (hb_closure_context_t *c) const
119  {
120    TRACE_CLOSURE (this);
121    Coverage::Iter iter;
122    for (iter.init (this+coverage); iter.more (); iter.next ()) {
123      if (c->glyphs->has (iter.get_glyph ()))
124	c->glyphs->add (substitute[iter.get_coverage ()]);
125    }
126  }
127
128  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
129  {
130    TRACE_COLLECT_GLYPHS (this);
131    Coverage::Iter iter;
132    for (iter.init (this+coverage); iter.more (); iter.next ()) {
133      c->input->add (iter.get_glyph ());
134      c->output->add (substitute[iter.get_coverage ()]);
135    }
136  }
137
138  inline const Coverage &get_coverage (void) const
139  {
140    return this+coverage;
141  }
142
143  inline bool would_apply (hb_would_apply_context_t *c) const
144  {
145    TRACE_WOULD_APPLY (this);
146    return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
147  }
148
149  inline bool apply (hb_apply_context_t *c) const
150  {
151    TRACE_APPLY (this);
152    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
153    unsigned int index = (this+coverage).get_coverage (glyph_id);
154    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
155
156    if (unlikely (index >= substitute.len)) return TRACE_RETURN (false);
157
158    glyph_id = substitute[index];
159    c->replace_glyph (glyph_id);
160
161    return TRACE_RETURN (true);
162  }
163
164  inline bool serialize (hb_serialize_context_t *c,
165			 Supplier<GlyphID> &glyphs,
166			 Supplier<GlyphID> &substitutes,
167			 unsigned int num_glyphs)
168  {
169    TRACE_SERIALIZE (this);
170    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
171    if (unlikely (!substitute.serialize (c, substitutes, num_glyphs))) return TRACE_RETURN (false);
172    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
173    return TRACE_RETURN (true);
174  }
175
176  inline bool sanitize (hb_sanitize_context_t *c) {
177    TRACE_SANITIZE (this);
178    return TRACE_RETURN (coverage.sanitize (c, this) && substitute.sanitize (c));
179  }
180
181  protected:
182  USHORT	format;			/* Format identifier--format = 2 */
183  OffsetTo<Coverage>
184		coverage;		/* Offset to Coverage table--from
185					 * beginning of Substitution table */
186  ArrayOf<GlyphID>
187		substitute;		/* Array of substitute
188					 * GlyphIDs--ordered by Coverage Index */
189  public:
190  DEFINE_SIZE_ARRAY (6, substitute);
191};
192
193struct SingleSubst
194{
195  inline bool serialize (hb_serialize_context_t *c,
196			 Supplier<GlyphID> &glyphs,
197			 Supplier<GlyphID> &substitutes,
198			 unsigned int num_glyphs)
199  {
200    TRACE_SERIALIZE (this);
201    if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
202    unsigned int format = 2;
203    int delta;
204    if (num_glyphs) {
205      format = 1;
206      /* TODO(serialize) check for wrap-around */
207      delta = substitutes[0] - glyphs[0];
208      for (unsigned int i = 1; i < num_glyphs; i++)
209	if (delta != substitutes[i] - glyphs[i]) {
210	  format = 2;
211	  break;
212	}
213    }
214    u.format.set (format);
215    switch (u.format) {
216    case 1: return TRACE_RETURN (u.format1.serialize (c, glyphs, num_glyphs, delta));
217    case 2: return TRACE_RETURN (u.format2.serialize (c, glyphs, substitutes, num_glyphs));
218    default:return TRACE_RETURN (false);
219    }
220  }
221
222  template <typename context_t>
223  inline typename context_t::return_t dispatch (context_t *c) const
224  {
225    TRACE_DISPATCH (this);
226    switch (u.format) {
227    case 1: return TRACE_RETURN (c->dispatch (u.format1));
228    case 2: return TRACE_RETURN (c->dispatch (u.format2));
229    default:return TRACE_RETURN (c->default_return_value ());
230    }
231  }
232
233  inline bool sanitize (hb_sanitize_context_t *c) {
234    TRACE_SANITIZE (this);
235    if (!u.format.sanitize (c)) return TRACE_RETURN (false);
236    switch (u.format) {
237    case 1: return TRACE_RETURN (u.format1.sanitize (c));
238    case 2: return TRACE_RETURN (u.format2.sanitize (c));
239    default:return TRACE_RETURN (true);
240    }
241  }
242
243  protected:
244  union {
245  USHORT		format;		/* Format identifier */
246  SingleSubstFormat1	format1;
247  SingleSubstFormat2	format2;
248  } u;
249};
250
251
252struct Sequence
253{
254  inline void closure (hb_closure_context_t *c) const
255  {
256    TRACE_CLOSURE (this);
257    unsigned int count = substitute.len;
258    for (unsigned int i = 0; i < count; i++)
259      c->glyphs->add (substitute[i]);
260  }
261
262  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
263  {
264    TRACE_COLLECT_GLYPHS (this);
265    unsigned int count = substitute.len;
266    for (unsigned int i = 0; i < count; i++)
267      c->output->add (substitute[i]);
268  }
269
270  inline bool apply (hb_apply_context_t *c) const
271  {
272    TRACE_APPLY (this);
273    unsigned int count = substitute.len;
274
275    /* TODO:
276     * Testing shows that Uniscribe actually allows zero-len susbstitute,
277     * which essentially deletes a glyph.  We don't allow for now.  It
278     * can be confusing to the client since the cluster from the deleted
279     * glyph won't be merged with any output cluster...  Also, currently
280     * buffer->move_to() makes assumptions about this too.  Perhaps fix
281     * in the future after figuring out what to do with the clusters.
282     */
283    if (unlikely (!count)) return TRACE_RETURN (false);
284
285    /* Special-case to make it in-place and not consider this
286     * as a "multiplied" substitution. */
287    if (unlikely (count == 1))
288    {
289      c->replace_glyph (substitute.array[0]);
290      return TRACE_RETURN (true);
291    }
292
293    unsigned int klass = _hb_glyph_info_is_ligature (&c->buffer->cur()) ?
294			 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH : 0;
295
296    for (unsigned int i = 0; i < count; i++) {
297      _hb_glyph_info_set_lig_props_for_component (&c->buffer->cur(), i);
298      c->output_glyph_for_component (substitute.array[i], klass);
299    }
300    c->buffer->skip_glyph ();
301
302    return TRACE_RETURN (true);
303  }
304
305  inline bool serialize (hb_serialize_context_t *c,
306			 Supplier<GlyphID> &glyphs,
307			 unsigned int num_glyphs)
308  {
309    TRACE_SERIALIZE (this);
310    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
311    if (unlikely (!substitute.serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
312    return TRACE_RETURN (true);
313  }
314
315  inline bool sanitize (hb_sanitize_context_t *c) {
316    TRACE_SANITIZE (this);
317    return TRACE_RETURN (substitute.sanitize (c));
318  }
319
320  protected:
321  ArrayOf<GlyphID>
322		substitute;		/* String of GlyphIDs to substitute */
323  public:
324  DEFINE_SIZE_ARRAY (2, substitute);
325};
326
327struct MultipleSubstFormat1
328{
329  inline void closure (hb_closure_context_t *c) const
330  {
331    TRACE_CLOSURE (this);
332    Coverage::Iter iter;
333    for (iter.init (this+coverage); iter.more (); iter.next ()) {
334      if (c->glyphs->has (iter.get_glyph ()))
335	(this+sequence[iter.get_coverage ()]).closure (c);
336    }
337  }
338
339  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
340  {
341    TRACE_COLLECT_GLYPHS (this);
342    (this+coverage).add_coverage (c->input);
343    unsigned int count = sequence.len;
344    for (unsigned int i = 0; i < count; i++)
345	(this+sequence[i]).collect_glyphs (c);
346  }
347
348  inline const Coverage &get_coverage (void) const
349  {
350    return this+coverage;
351  }
352
353  inline bool would_apply (hb_would_apply_context_t *c) const
354  {
355    TRACE_WOULD_APPLY (this);
356    return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
357  }
358
359  inline bool apply (hb_apply_context_t *c) const
360  {
361    TRACE_APPLY (this);
362
363    unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
364    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
365
366    return TRACE_RETURN ((this+sequence[index]).apply (c));
367  }
368
369  inline bool serialize (hb_serialize_context_t *c,
370			 Supplier<GlyphID> &glyphs,
371			 Supplier<unsigned int> &substitute_len_list,
372			 unsigned int num_glyphs,
373			 Supplier<GlyphID> &substitute_glyphs_list)
374  {
375    TRACE_SERIALIZE (this);
376    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
377    if (unlikely (!sequence.serialize (c, num_glyphs))) return TRACE_RETURN (false);
378    for (unsigned int i = 0; i < num_glyphs; i++)
379      if (unlikely (!sequence[i].serialize (c, this).serialize (c,
380								substitute_glyphs_list,
381								substitute_len_list[i]))) return TRACE_RETURN (false);
382    substitute_len_list.advance (num_glyphs);
383    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
384    return TRACE_RETURN (true);
385  }
386
387  inline bool sanitize (hb_sanitize_context_t *c) {
388    TRACE_SANITIZE (this);
389    return TRACE_RETURN (coverage.sanitize (c, this) && sequence.sanitize (c, this));
390  }
391
392  protected:
393  USHORT	format;			/* Format identifier--format = 1 */
394  OffsetTo<Coverage>
395		coverage;		/* Offset to Coverage table--from
396					 * beginning of Substitution table */
397  OffsetArrayOf<Sequence>
398		sequence;		/* Array of Sequence tables
399					 * ordered by Coverage Index */
400  public:
401  DEFINE_SIZE_ARRAY (6, sequence);
402};
403
404struct MultipleSubst
405{
406  inline bool serialize (hb_serialize_context_t *c,
407			 Supplier<GlyphID> &glyphs,
408			 Supplier<unsigned int> &substitute_len_list,
409			 unsigned int num_glyphs,
410			 Supplier<GlyphID> &substitute_glyphs_list)
411  {
412    TRACE_SERIALIZE (this);
413    if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
414    unsigned int format = 1;
415    u.format.set (format);
416    switch (u.format) {
417    case 1: return TRACE_RETURN (u.format1.serialize (c, glyphs, substitute_len_list, num_glyphs, substitute_glyphs_list));
418    default:return TRACE_RETURN (false);
419    }
420  }
421
422  template <typename context_t>
423  inline typename context_t::return_t dispatch (context_t *c) const
424  {
425    TRACE_DISPATCH (this);
426    switch (u.format) {
427    case 1: return TRACE_RETURN (c->dispatch (u.format1));
428    default:return TRACE_RETURN (c->default_return_value ());
429    }
430  }
431
432  inline bool sanitize (hb_sanitize_context_t *c) {
433    TRACE_SANITIZE (this);
434    if (!u.format.sanitize (c)) return TRACE_RETURN (false);
435    switch (u.format) {
436    case 1: return TRACE_RETURN (u.format1.sanitize (c));
437    default:return TRACE_RETURN (true);
438    }
439  }
440
441  protected:
442  union {
443  USHORT		format;		/* Format identifier */
444  MultipleSubstFormat1	format1;
445  } u;
446};
447
448
449typedef ArrayOf<GlyphID> AlternateSet;	/* Array of alternate GlyphIDs--in
450					 * arbitrary order */
451
452struct AlternateSubstFormat1
453{
454  inline void closure (hb_closure_context_t *c) const
455  {
456    TRACE_CLOSURE (this);
457    Coverage::Iter iter;
458    for (iter.init (this+coverage); iter.more (); iter.next ()) {
459      if (c->glyphs->has (iter.get_glyph ())) {
460	const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
461	unsigned int count = alt_set.len;
462	for (unsigned int i = 0; i < count; i++)
463	  c->glyphs->add (alt_set[i]);
464      }
465    }
466  }
467
468  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
469  {
470    TRACE_COLLECT_GLYPHS (this);
471    Coverage::Iter iter;
472    for (iter.init (this+coverage); iter.more (); iter.next ()) {
473      c->input->add (iter.get_glyph ());
474      const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
475      unsigned int count = alt_set.len;
476      for (unsigned int i = 0; i < count; i++)
477	c->output->add (alt_set[i]);
478    }
479  }
480
481  inline const Coverage &get_coverage (void) const
482  {
483    return this+coverage;
484  }
485
486  inline bool would_apply (hb_would_apply_context_t *c) const
487  {
488    TRACE_WOULD_APPLY (this);
489    return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
490  }
491
492  inline bool apply (hb_apply_context_t *c) const
493  {
494    TRACE_APPLY (this);
495    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
496
497    unsigned int index = (this+coverage).get_coverage (glyph_id);
498    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
499
500    const AlternateSet &alt_set = this+alternateSet[index];
501
502    if (unlikely (!alt_set.len)) return TRACE_RETURN (false);
503
504    hb_mask_t glyph_mask = c->buffer->cur().mask;
505    hb_mask_t lookup_mask = c->lookup_mask;
506
507    /* Note: This breaks badly if two features enabled this lookup together. */
508    unsigned int shift = _hb_ctz (lookup_mask);
509    unsigned int alt_index = ((lookup_mask & glyph_mask) >> shift);
510
511    if (unlikely (alt_index > alt_set.len || alt_index == 0)) return TRACE_RETURN (false);
512
513    glyph_id = alt_set[alt_index - 1];
514
515    c->replace_glyph (glyph_id);
516
517    return TRACE_RETURN (true);
518  }
519
520  inline bool serialize (hb_serialize_context_t *c,
521			 Supplier<GlyphID> &glyphs,
522			 Supplier<unsigned int> &alternate_len_list,
523			 unsigned int num_glyphs,
524			 Supplier<GlyphID> &alternate_glyphs_list)
525  {
526    TRACE_SERIALIZE (this);
527    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
528    if (unlikely (!alternateSet.serialize (c, num_glyphs))) return TRACE_RETURN (false);
529    for (unsigned int i = 0; i < num_glyphs; i++)
530      if (unlikely (!alternateSet[i].serialize (c, this).serialize (c,
531								    alternate_glyphs_list,
532								    alternate_len_list[i]))) return TRACE_RETURN (false);
533    alternate_len_list.advance (num_glyphs);
534    if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
535    return TRACE_RETURN (true);
536  }
537
538  inline bool sanitize (hb_sanitize_context_t *c) {
539    TRACE_SANITIZE (this);
540    return TRACE_RETURN (coverage.sanitize (c, this) && alternateSet.sanitize (c, this));
541  }
542
543  protected:
544  USHORT	format;			/* Format identifier--format = 1 */
545  OffsetTo<Coverage>
546		coverage;		/* Offset to Coverage table--from
547					 * beginning of Substitution table */
548  OffsetArrayOf<AlternateSet>
549		alternateSet;		/* Array of AlternateSet tables
550					 * ordered by Coverage Index */
551  public:
552  DEFINE_SIZE_ARRAY (6, alternateSet);
553};
554
555struct AlternateSubst
556{
557  inline bool serialize (hb_serialize_context_t *c,
558			 Supplier<GlyphID> &glyphs,
559			 Supplier<unsigned int> &alternate_len_list,
560			 unsigned int num_glyphs,
561			 Supplier<GlyphID> &alternate_glyphs_list)
562  {
563    TRACE_SERIALIZE (this);
564    if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
565    unsigned int format = 1;
566    u.format.set (format);
567    switch (u.format) {
568    case 1: return TRACE_RETURN (u.format1.serialize (c, glyphs, alternate_len_list, num_glyphs, alternate_glyphs_list));
569    default:return TRACE_RETURN (false);
570    }
571  }
572
573  template <typename context_t>
574  inline typename context_t::return_t dispatch (context_t *c) const
575  {
576    TRACE_DISPATCH (this);
577    switch (u.format) {
578    case 1: return TRACE_RETURN (c->dispatch (u.format1));
579    default:return TRACE_RETURN (c->default_return_value ());
580    }
581  }
582
583  inline bool sanitize (hb_sanitize_context_t *c) {
584    TRACE_SANITIZE (this);
585    if (!u.format.sanitize (c)) return TRACE_RETURN (false);
586    switch (u.format) {
587    case 1: return TRACE_RETURN (u.format1.sanitize (c));
588    default:return TRACE_RETURN (true);
589    }
590  }
591
592  protected:
593  union {
594  USHORT		format;		/* Format identifier */
595  AlternateSubstFormat1	format1;
596  } u;
597};
598
599
600struct Ligature
601{
602  inline void closure (hb_closure_context_t *c) const
603  {
604    TRACE_CLOSURE (this);
605    unsigned int count = component.len;
606    for (unsigned int i = 1; i < count; i++)
607      if (!c->glyphs->has (component[i]))
608        return;
609    c->glyphs->add (ligGlyph);
610  }
611
612  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
613  {
614    TRACE_COLLECT_GLYPHS (this);
615    unsigned int count = component.len;
616    for (unsigned int i = 1; i < count; i++)
617      c->input->add (component[i]);
618    c->output->add (ligGlyph);
619  }
620
621  inline bool would_apply (hb_would_apply_context_t *c) const
622  {
623    TRACE_WOULD_APPLY (this);
624    if (c->len != component.len)
625      return TRACE_RETURN (false);
626
627    for (unsigned int i = 1; i < c->len; i++)
628      if (likely (c->glyphs[i] != component[i]))
629	return TRACE_RETURN (false);
630
631    return TRACE_RETURN (true);
632  }
633
634  inline bool apply (hb_apply_context_t *c) const
635  {
636    TRACE_APPLY (this);
637    unsigned int count = component.len;
638
639    if (unlikely (!count)) return TRACE_RETURN (false);
640
641    /* Special-case to make it in-place and not consider this
642     * as a "ligated" substitution. */
643    if (unlikely (count == 1))
644    {
645      c->replace_glyph (ligGlyph);
646      return TRACE_RETURN (true);
647    }
648
649    bool is_mark_ligature = false;
650    unsigned int total_component_count = 0;
651
652    unsigned int match_length = 0;
653    unsigned int match_positions[MAX_CONTEXT_LENGTH];
654
655    if (likely (!match_input (c, count,
656			      &component[1],
657			      match_glyph,
658			      NULL,
659			      &match_length,
660			      match_positions,
661			      &is_mark_ligature,
662			      &total_component_count)))
663      return TRACE_RETURN (false);
664
665    ligate_input (c,
666		  count,
667		  match_positions,
668		  match_length,
669		  ligGlyph,
670		  is_mark_ligature,
671		  total_component_count);
672
673    return TRACE_RETURN (true);
674  }
675
676  inline bool serialize (hb_serialize_context_t *c,
677			 GlyphID ligature,
678			 Supplier<GlyphID> &components, /* Starting from second */
679			 unsigned int num_components /* Including first component */)
680  {
681    TRACE_SERIALIZE (this);
682    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
683    ligGlyph = ligature;
684    if (unlikely (!component.serialize (c, components, num_components))) return TRACE_RETURN (false);
685    return TRACE_RETURN (true);
686  }
687
688  public:
689  inline bool sanitize (hb_sanitize_context_t *c) {
690    TRACE_SANITIZE (this);
691    return TRACE_RETURN (ligGlyph.sanitize (c) && component.sanitize (c));
692  }
693
694  protected:
695  GlyphID	ligGlyph;		/* GlyphID of ligature to substitute */
696  HeadlessArrayOf<GlyphID>
697		component;		/* Array of component GlyphIDs--start
698					 * with the second  component--ordered
699					 * in writing direction */
700  public:
701  DEFINE_SIZE_ARRAY (4, component);
702};
703
704struct LigatureSet
705{
706  inline void closure (hb_closure_context_t *c) const
707  {
708    TRACE_CLOSURE (this);
709    unsigned int num_ligs = ligature.len;
710    for (unsigned int i = 0; i < num_ligs; i++)
711      (this+ligature[i]).closure (c);
712  }
713
714  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
715  {
716    TRACE_COLLECT_GLYPHS (this);
717    unsigned int num_ligs = ligature.len;
718    for (unsigned int i = 0; i < num_ligs; i++)
719      (this+ligature[i]).collect_glyphs (c);
720  }
721
722  inline bool would_apply (hb_would_apply_context_t *c) const
723  {
724    TRACE_WOULD_APPLY (this);
725    unsigned int num_ligs = ligature.len;
726    for (unsigned int i = 0; i < num_ligs; i++)
727    {
728      const Ligature &lig = this+ligature[i];
729      if (lig.would_apply (c))
730        return TRACE_RETURN (true);
731    }
732    return TRACE_RETURN (false);
733  }
734
735  inline bool apply (hb_apply_context_t *c) const
736  {
737    TRACE_APPLY (this);
738    unsigned int num_ligs = ligature.len;
739    for (unsigned int i = 0; i < num_ligs; i++)
740    {
741      const Ligature &lig = this+ligature[i];
742      if (lig.apply (c)) return TRACE_RETURN (true);
743    }
744
745    return TRACE_RETURN (false);
746  }
747
748  inline bool serialize (hb_serialize_context_t *c,
749			 Supplier<GlyphID> &ligatures,
750			 Supplier<unsigned int> &component_count_list,
751			 unsigned int num_ligatures,
752			 Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
753  {
754    TRACE_SERIALIZE (this);
755    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
756    if (unlikely (!ligature.serialize (c, num_ligatures))) return TRACE_RETURN (false);
757    for (unsigned int i = 0; i < num_ligatures; i++)
758      if (unlikely (!ligature[i].serialize (c, this).serialize (c,
759								ligatures[i],
760								component_list,
761								component_count_list[i]))) return TRACE_RETURN (false);
762    ligatures.advance (num_ligatures);
763    component_count_list.advance (num_ligatures);
764    return TRACE_RETURN (true);
765  }
766
767  inline bool sanitize (hb_sanitize_context_t *c) {
768    TRACE_SANITIZE (this);
769    return TRACE_RETURN (ligature.sanitize (c, this));
770  }
771
772  protected:
773  OffsetArrayOf<Ligature>
774		ligature;		/* Array LigatureSet tables
775					 * ordered by preference */
776  public:
777  DEFINE_SIZE_ARRAY (2, ligature);
778};
779
780struct LigatureSubstFormat1
781{
782  inline void closure (hb_closure_context_t *c) const
783  {
784    TRACE_CLOSURE (this);
785    Coverage::Iter iter;
786    for (iter.init (this+coverage); iter.more (); iter.next ()) {
787      if (c->glyphs->has (iter.get_glyph ()))
788	(this+ligatureSet[iter.get_coverage ()]).closure (c);
789    }
790  }
791
792  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
793  {
794    TRACE_COLLECT_GLYPHS (this);
795    Coverage::Iter iter;
796    for (iter.init (this+coverage); iter.more (); iter.next ()) {
797      c->input->add (iter.get_glyph ());
798      (this+ligatureSet[iter.get_coverage ()]).collect_glyphs (c);
799    }
800  }
801
802  inline const Coverage &get_coverage (void) const
803  {
804    return this+coverage;
805  }
806
807  inline bool would_apply (hb_would_apply_context_t *c) const
808  {
809    TRACE_WOULD_APPLY (this);
810    unsigned int index = (this+coverage).get_coverage (c->glyphs[0]);
811    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
812
813    const LigatureSet &lig_set = this+ligatureSet[index];
814    return TRACE_RETURN (lig_set.would_apply (c));
815  }
816
817  inline bool apply (hb_apply_context_t *c) const
818  {
819    TRACE_APPLY (this);
820    hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
821
822    unsigned int index = (this+coverage).get_coverage (glyph_id);
823    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
824
825    const LigatureSet &lig_set = this+ligatureSet[index];
826    return TRACE_RETURN (lig_set.apply (c));
827  }
828
829  inline bool serialize (hb_serialize_context_t *c,
830			 Supplier<GlyphID> &first_glyphs,
831			 Supplier<unsigned int> &ligature_per_first_glyph_count_list,
832			 unsigned int num_first_glyphs,
833			 Supplier<GlyphID> &ligatures_list,
834			 Supplier<unsigned int> &component_count_list,
835			 Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
836  {
837    TRACE_SERIALIZE (this);
838    if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
839    if (unlikely (!ligatureSet.serialize (c, num_first_glyphs))) return TRACE_RETURN (false);
840    for (unsigned int i = 0; i < num_first_glyphs; i++)
841      if (unlikely (!ligatureSet[i].serialize (c, this).serialize (c,
842								   ligatures_list,
843								   component_count_list,
844								   ligature_per_first_glyph_count_list[i],
845								   component_list))) return TRACE_RETURN (false);
846    ligature_per_first_glyph_count_list.advance (num_first_glyphs);
847    if (unlikely (!coverage.serialize (c, this).serialize (c, first_glyphs, num_first_glyphs))) return TRACE_RETURN (false);
848    return TRACE_RETURN (true);
849  }
850
851  inline bool sanitize (hb_sanitize_context_t *c) {
852    TRACE_SANITIZE (this);
853    return TRACE_RETURN (coverage.sanitize (c, this) && ligatureSet.sanitize (c, this));
854  }
855
856  protected:
857  USHORT	format;			/* Format identifier--format = 1 */
858  OffsetTo<Coverage>
859		coverage;		/* Offset to Coverage table--from
860					 * beginning of Substitution table */
861  OffsetArrayOf<LigatureSet>
862		ligatureSet;		/* Array LigatureSet tables
863					 * ordered by Coverage Index */
864  public:
865  DEFINE_SIZE_ARRAY (6, ligatureSet);
866};
867
868struct LigatureSubst
869{
870  inline bool serialize (hb_serialize_context_t *c,
871			 Supplier<GlyphID> &first_glyphs,
872			 Supplier<unsigned int> &ligature_per_first_glyph_count_list,
873			 unsigned int num_first_glyphs,
874			 Supplier<GlyphID> &ligatures_list,
875			 Supplier<unsigned int> &component_count_list,
876			 Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
877  {
878    TRACE_SERIALIZE (this);
879    if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
880    unsigned int format = 1;
881    u.format.set (format);
882    switch (u.format) {
883    case 1: return TRACE_RETURN (u.format1.serialize (c, first_glyphs, ligature_per_first_glyph_count_list, num_first_glyphs,
884						      ligatures_list, component_count_list, component_list));
885    default:return TRACE_RETURN (false);
886    }
887  }
888
889  template <typename context_t>
890  inline typename context_t::return_t dispatch (context_t *c) const
891  {
892    TRACE_DISPATCH (this);
893    switch (u.format) {
894    case 1: return TRACE_RETURN (c->dispatch (u.format1));
895    default:return TRACE_RETURN (c->default_return_value ());
896    }
897  }
898
899  inline bool sanitize (hb_sanitize_context_t *c) {
900    TRACE_SANITIZE (this);
901    if (!u.format.sanitize (c)) return TRACE_RETURN (false);
902    switch (u.format) {
903    case 1: return TRACE_RETURN (u.format1.sanitize (c));
904    default:return TRACE_RETURN (true);
905    }
906  }
907
908  protected:
909  union {
910  USHORT		format;		/* Format identifier */
911  LigatureSubstFormat1	format1;
912  } u;
913};
914
915
916struct ContextSubst : Context {};
917
918struct ChainContextSubst : ChainContext {};
919
920struct ExtensionSubst : Extension<ExtensionSubst>
921{
922  typedef struct SubstLookupSubTable LookupSubTable;
923
924  inline bool is_reverse (void) const;
925};
926
927
928struct ReverseChainSingleSubstFormat1
929{
930  inline void closure (hb_closure_context_t *c) const
931  {
932    TRACE_CLOSURE (this);
933    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
934
935    unsigned int count;
936
937    count = backtrack.len;
938    for (unsigned int i = 0; i < count; i++)
939      if (!(this+backtrack[i]).intersects (c->glyphs))
940        return;
941
942    count = lookahead.len;
943    for (unsigned int i = 0; i < count; i++)
944      if (!(this+lookahead[i]).intersects (c->glyphs))
945        return;
946
947    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
948    Coverage::Iter iter;
949    for (iter.init (this+coverage); iter.more (); iter.next ()) {
950      if (c->glyphs->has (iter.get_glyph ()))
951	c->glyphs->add (substitute[iter.get_coverage ()]);
952    }
953  }
954
955  inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
956  {
957    TRACE_COLLECT_GLYPHS (this);
958
959    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
960
961    unsigned int count;
962
963    (this+coverage).add_coverage (c->input);
964
965    count = backtrack.len;
966    for (unsigned int i = 0; i < count; i++)
967      (this+backtrack[i]).add_coverage (c->before);
968
969    count = lookahead.len;
970    for (unsigned int i = 0; i < count; i++)
971      (this+lookahead[i]).add_coverage (c->after);
972
973    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
974    count = substitute.len;
975    for (unsigned int i = 0; i < count; i++)
976      c->output->add (substitute[i]);
977  }
978
979  inline const Coverage &get_coverage (void) const
980  {
981    return this+coverage;
982  }
983
984  inline bool would_apply (hb_would_apply_context_t *c) const
985  {
986    TRACE_WOULD_APPLY (this);
987    return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
988  }
989
990  inline bool apply (hb_apply_context_t *c) const
991  {
992    TRACE_APPLY (this);
993    if (unlikely (c->nesting_level_left != MAX_NESTING_LEVEL))
994      return TRACE_RETURN (false); /* No chaining to this type */
995
996    unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
997    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
998
999    const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
1000    const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
1001
1002    if (match_backtrack (c,
1003			 backtrack.len, (USHORT *) backtrack.array,
1004			 match_coverage, this) &&
1005        match_lookahead (c,
1006			 lookahead.len, (USHORT *) lookahead.array,
1007			 match_coverage, this,
1008			 1))
1009    {
1010      c->replace_glyph_inplace (substitute[index]);
1011      /* Note: We DON'T decrease buffer->idx.  The main loop does it
1012       * for us.  This is useful for preventing surprises if someone
1013       * calls us through a Context lookup. */
1014      return TRACE_RETURN (true);
1015    }
1016
1017    return TRACE_RETURN (false);
1018  }
1019
1020  inline bool sanitize (hb_sanitize_context_t *c) {
1021    TRACE_SANITIZE (this);
1022    if (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this)))
1023      return TRACE_RETURN (false);
1024    OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
1025    if (!lookahead.sanitize (c, this))
1026      return TRACE_RETURN (false);
1027    ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
1028    return TRACE_RETURN (substitute.sanitize (c));
1029  }
1030
1031  protected:
1032  USHORT	format;			/* Format identifier--format = 1 */
1033  OffsetTo<Coverage>
1034		coverage;		/* Offset to Coverage table--from
1035					 * beginning of table */
1036  OffsetArrayOf<Coverage>
1037		backtrack;		/* Array of coverage tables
1038					 * in backtracking sequence, in  glyph
1039					 * sequence order */
1040  OffsetArrayOf<Coverage>
1041		lookaheadX;		/* Array of coverage tables
1042					 * in lookahead sequence, in glyph
1043					 * sequence order */
1044  ArrayOf<GlyphID>
1045		substituteX;		/* Array of substitute
1046					 * GlyphIDs--ordered by Coverage Index */
1047  public:
1048  DEFINE_SIZE_MIN (10);
1049};
1050
1051struct ReverseChainSingleSubst
1052{
1053  template <typename context_t>
1054  inline typename context_t::return_t dispatch (context_t *c) const
1055  {
1056    TRACE_DISPATCH (this);
1057    switch (u.format) {
1058    case 1: return TRACE_RETURN (c->dispatch (u.format1));
1059    default:return TRACE_RETURN (c->default_return_value ());
1060    }
1061  }
1062
1063  inline bool sanitize (hb_sanitize_context_t *c) {
1064    TRACE_SANITIZE (this);
1065    if (!u.format.sanitize (c)) return TRACE_RETURN (false);
1066    switch (u.format) {
1067    case 1: return TRACE_RETURN (u.format1.sanitize (c));
1068    default:return TRACE_RETURN (true);
1069    }
1070  }
1071
1072  protected:
1073  union {
1074  USHORT				format;		/* Format identifier */
1075  ReverseChainSingleSubstFormat1	format1;
1076  } u;
1077};
1078
1079
1080
1081/*
1082 * SubstLookup
1083 */
1084
1085struct SubstLookupSubTable
1086{
1087  friend struct SubstLookup;
1088
1089  enum Type {
1090    Single		= 1,
1091    Multiple		= 2,
1092    Alternate		= 3,
1093    Ligature		= 4,
1094    Context		= 5,
1095    ChainContext	= 6,
1096    Extension		= 7,
1097    ReverseChainSingle	= 8
1098  };
1099
1100  template <typename context_t>
1101  inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
1102  {
1103    TRACE_DISPATCH (this);
1104    switch (lookup_type) {
1105    case Single:		return TRACE_RETURN (u.single.dispatch (c));
1106    case Multiple:		return TRACE_RETURN (u.multiple.dispatch (c));
1107    case Alternate:		return TRACE_RETURN (u.alternate.dispatch (c));
1108    case Ligature:		return TRACE_RETURN (u.ligature.dispatch (c));
1109    case Context:		return TRACE_RETURN (u.context.dispatch (c));
1110    case ChainContext:		return TRACE_RETURN (u.chainContext.dispatch (c));
1111    case Extension:		return TRACE_RETURN (u.extension.dispatch (c));
1112    case ReverseChainSingle:	return TRACE_RETURN (u.reverseChainContextSingle.dispatch (c));
1113    default:			return TRACE_RETURN (c->default_return_value ());
1114    }
1115  }
1116
1117  inline bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) {
1118    TRACE_SANITIZE (this);
1119    if (!u.header.sub_format.sanitize (c))
1120      return TRACE_RETURN (false);
1121    switch (lookup_type) {
1122    case Single:		return TRACE_RETURN (u.single.sanitize (c));
1123    case Multiple:		return TRACE_RETURN (u.multiple.sanitize (c));
1124    case Alternate:		return TRACE_RETURN (u.alternate.sanitize (c));
1125    case Ligature:		return TRACE_RETURN (u.ligature.sanitize (c));
1126    case Context:		return TRACE_RETURN (u.context.sanitize (c));
1127    case ChainContext:		return TRACE_RETURN (u.chainContext.sanitize (c));
1128    case Extension:		return TRACE_RETURN (u.extension.sanitize (c));
1129    case ReverseChainSingle:	return TRACE_RETURN (u.reverseChainContextSingle.sanitize (c));
1130    default:			return TRACE_RETURN (true);
1131    }
1132  }
1133
1134  protected:
1135  union {
1136  struct {
1137    USHORT			sub_format;
1138  } header;
1139  SingleSubst			single;
1140  MultipleSubst			multiple;
1141  AlternateSubst		alternate;
1142  LigatureSubst			ligature;
1143  ContextSubst			context;
1144  ChainContextSubst		chainContext;
1145  ExtensionSubst		extension;
1146  ReverseChainSingleSubst	reverseChainContextSingle;
1147  } u;
1148  public:
1149  DEFINE_SIZE_UNION (2, header.sub_format);
1150};
1151
1152
1153struct SubstLookup : Lookup
1154{
1155  inline const SubstLookupSubTable& get_subtable (unsigned int i) const
1156  { return this+CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i]; }
1157
1158  inline static bool lookup_type_is_reverse (unsigned int lookup_type)
1159  { return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
1160
1161  inline bool is_reverse (void) const
1162  {
1163    unsigned int type = get_type ();
1164    if (unlikely (type == SubstLookupSubTable::Extension))
1165      return CastR<ExtensionSubst> (get_subtable(0)).is_reverse ();
1166    return lookup_type_is_reverse (type);
1167  }
1168
1169  inline hb_closure_context_t::return_t closure (hb_closure_context_t *c) const
1170  {
1171    TRACE_CLOSURE (this);
1172    c->set_recurse_func (dispatch_recurse_func<hb_closure_context_t>);
1173    return TRACE_RETURN (dispatch (c));
1174  }
1175
1176  inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
1177  {
1178    TRACE_COLLECT_GLYPHS (this);
1179    c->set_recurse_func (dispatch_recurse_func<hb_collect_glyphs_context_t>);
1180    return TRACE_RETURN (dispatch (c));
1181  }
1182
1183  template <typename set_t>
1184  inline void add_coverage (set_t *glyphs) const
1185  {
1186    hb_get_coverage_context_t c;
1187    const Coverage *last = NULL;
1188    unsigned int count = get_subtable_count ();
1189    for (unsigned int i = 0; i < count; i++) {
1190      const Coverage *coverage = &get_subtable (i).dispatch (&c, get_type ());
1191      if (coverage != last) {
1192        coverage->add_coverage (glyphs);
1193        last = coverage;
1194      }
1195    }
1196  }
1197
1198  inline bool would_apply (hb_would_apply_context_t *c, const hb_set_digest_t *digest) const
1199  {
1200    TRACE_WOULD_APPLY (this);
1201    if (unlikely (!c->len))  return TRACE_RETURN (false);
1202    if (!digest->may_have (c->glyphs[0]))  return TRACE_RETURN (false);
1203      return TRACE_RETURN (dispatch (c));
1204  }
1205
1206  inline bool apply_once (hb_apply_context_t *c) const
1207  {
1208    TRACE_APPLY (this);
1209    if (!c->check_glyph_property (&c->buffer->cur(), c->lookup_props))
1210      return TRACE_RETURN (false);
1211    return TRACE_RETURN (dispatch (c));
1212  }
1213
1214  static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
1215
1216  inline SubstLookupSubTable& serialize_subtable (hb_serialize_context_t *c,
1217						  unsigned int i)
1218  { return CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i].serialize (c, this); }
1219
1220  inline bool serialize_single (hb_serialize_context_t *c,
1221				uint32_t lookup_props,
1222			        Supplier<GlyphID> &glyphs,
1223			        Supplier<GlyphID> &substitutes,
1224			        unsigned int num_glyphs)
1225  {
1226    TRACE_SERIALIZE (this);
1227    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Single, lookup_props, 1))) return TRACE_RETURN (false);
1228    return TRACE_RETURN (serialize_subtable (c, 0).u.single.serialize (c, glyphs, substitutes, num_glyphs));
1229  }
1230
1231  inline bool serialize_multiple (hb_serialize_context_t *c,
1232				  uint32_t lookup_props,
1233				  Supplier<GlyphID> &glyphs,
1234				  Supplier<unsigned int> &substitute_len_list,
1235				  unsigned int num_glyphs,
1236				  Supplier<GlyphID> &substitute_glyphs_list)
1237  {
1238    TRACE_SERIALIZE (this);
1239    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Multiple, lookup_props, 1))) return TRACE_RETURN (false);
1240    return TRACE_RETURN (serialize_subtable (c, 0).u.multiple.serialize (c, glyphs, substitute_len_list, num_glyphs,
1241									 substitute_glyphs_list));
1242  }
1243
1244  inline bool serialize_alternate (hb_serialize_context_t *c,
1245				   uint32_t lookup_props,
1246				   Supplier<GlyphID> &glyphs,
1247				   Supplier<unsigned int> &alternate_len_list,
1248				   unsigned int num_glyphs,
1249				   Supplier<GlyphID> &alternate_glyphs_list)
1250  {
1251    TRACE_SERIALIZE (this);
1252    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Alternate, lookup_props, 1))) return TRACE_RETURN (false);
1253    return TRACE_RETURN (serialize_subtable (c, 0).u.alternate.serialize (c, glyphs, alternate_len_list, num_glyphs,
1254									  alternate_glyphs_list));
1255  }
1256
1257  inline bool serialize_ligature (hb_serialize_context_t *c,
1258				  uint32_t lookup_props,
1259				  Supplier<GlyphID> &first_glyphs,
1260				  Supplier<unsigned int> &ligature_per_first_glyph_count_list,
1261				  unsigned int num_first_glyphs,
1262				  Supplier<GlyphID> &ligatures_list,
1263				  Supplier<unsigned int> &component_count_list,
1264				  Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
1265  {
1266    TRACE_SERIALIZE (this);
1267    if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Ligature, lookup_props, 1))) return TRACE_RETURN (false);
1268    return TRACE_RETURN (serialize_subtable (c, 0).u.ligature.serialize (c, first_glyphs, ligature_per_first_glyph_count_list, num_first_glyphs,
1269									 ligatures_list, component_count_list, component_list));
1270  }
1271
1272  template <typename context_t>
1273  static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
1274
1275  template <typename context_t>
1276  inline typename context_t::return_t dispatch (context_t *c) const
1277  {
1278    TRACE_DISPATCH (this);
1279    unsigned int lookup_type = get_type ();
1280    unsigned int count = get_subtable_count ();
1281    for (unsigned int i = 0; i < count; i++) {
1282      typename context_t::return_t r = get_subtable (i).dispatch (c, lookup_type);
1283      if (c->stop_sublookup_iteration (r))
1284        return TRACE_RETURN (r);
1285    }
1286    return TRACE_RETURN (c->default_return_value ());
1287  }
1288
1289  inline bool sanitize (hb_sanitize_context_t *c)
1290  {
1291    TRACE_SANITIZE (this);
1292    if (unlikely (!Lookup::sanitize (c))) return TRACE_RETURN (false);
1293    OffsetArrayOf<SubstLookupSubTable> &list = CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable);
1294    if (unlikely (!list.sanitize (c, this, get_type ()))) return TRACE_RETURN (false);
1295
1296    if (unlikely (get_type () == SubstLookupSubTable::Extension))
1297    {
1298      /* The spec says all subtables of an Extension lookup should
1299       * have the same type.  This is specially important if one has
1300       * a reverse type! */
1301      unsigned int type = get_subtable (0).u.extension.get_type ();
1302      unsigned int count = get_subtable_count ();
1303      for (unsigned int i = 1; i < count; i++)
1304        if (get_subtable (i).u.extension.get_type () != type)
1305	  return TRACE_RETURN (false);
1306    }
1307    return TRACE_RETURN (true);
1308  }
1309};
1310
1311typedef OffsetListOf<SubstLookup> SubstLookupList;
1312
1313/*
1314 * GSUB -- The Glyph Substitution Table
1315 */
1316
1317struct GSUB : GSUBGPOS
1318{
1319  static const hb_tag_t tableTag	= HB_OT_TAG_GSUB;
1320
1321  inline const SubstLookup& get_lookup (unsigned int i) const
1322  { return CastR<SubstLookup> (GSUBGPOS::get_lookup (i)); }
1323
1324  static inline void substitute_start (hb_font_t *font, hb_buffer_t *buffer);
1325  static inline void substitute_finish (hb_font_t *font, hb_buffer_t *buffer);
1326
1327  inline bool sanitize (hb_sanitize_context_t *c) {
1328    TRACE_SANITIZE (this);
1329    if (unlikely (!GSUBGPOS::sanitize (c))) return TRACE_RETURN (false);
1330    OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
1331    return TRACE_RETURN (list.sanitize (c, this));
1332  }
1333  public:
1334  DEFINE_SIZE_STATIC (10);
1335};
1336
1337
1338void
1339GSUB::substitute_start (hb_font_t *font, hb_buffer_t *buffer)
1340{
1341  _hb_buffer_assert_gsubgpos_vars (buffer);
1342
1343  const GDEF &gdef = *hb_ot_layout_from_face (font->face)->gdef;
1344  unsigned int count = buffer->len;
1345  for (unsigned int i = 0; i < count; i++)
1346  {
1347    _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
1348    _hb_glyph_info_clear_lig_props (&buffer->info[i]);
1349    buffer->info[i].syllable() = 0;
1350  }
1351}
1352
1353void
1354GSUB::substitute_finish (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer HB_UNUSED)
1355{
1356}
1357
1358
1359/* Out-of-class implementation for methods recursing */
1360
1361/*static*/ inline bool ExtensionSubst::is_reverse (void) const
1362{
1363  unsigned int type = get_type ();
1364  if (unlikely (type == SubstLookupSubTable::Extension))
1365    return CastR<ExtensionSubst> (get_subtable<SubstLookupSubTable>()).is_reverse ();
1366  return SubstLookup::lookup_type_is_reverse (type);
1367}
1368
1369template <typename context_t>
1370/*static*/ inline typename context_t::return_t SubstLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
1371{
1372  const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
1373  const SubstLookup &l = gsub.get_lookup (lookup_index);
1374  return l.dispatch (c);
1375}
1376
1377/*static*/ inline bool SubstLookup::apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index)
1378{
1379  const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
1380  const SubstLookup &l = gsub.get_lookup (lookup_index);
1381  unsigned int saved_lookup_props = c->lookup_props;
1382  c->set_lookup (l);
1383  bool ret = l.apply_once (c);
1384  c->lookup_props = saved_lookup_props;
1385  return ret;
1386}
1387
1388
1389} /* namespace OT */
1390
1391
1392#endif /* HB_OT_LAYOUT_GSUB_TABLE_HH */
1393