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 
35 namespace OT {
36 
37 
38 struct SingleSubstFormat1
39 {
closureOT::SingleSubstFormat140   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 
collect_glyphsOT::SingleSubstFormat151   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 
get_coverageOT::SingleSubstFormat162   inline const Coverage &get_coverage (void) const
63   {
64     return this+coverage;
65   }
66 
would_applyOT::SingleSubstFormat167   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 
applyOT::SingleSubstFormat173   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 
serializeOT::SingleSubstFormat188   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 
sanitizeOT::SingleSubstFormat1100   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 
116 struct SingleSubstFormat2
117 {
closureOT::SingleSubstFormat2118   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 
collect_glyphsOT::SingleSubstFormat2128   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 
get_coverageOT::SingleSubstFormat2138   inline const Coverage &get_coverage (void) const
139   {
140     return this+coverage;
141   }
142 
would_applyOT::SingleSubstFormat2143   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 
applyOT::SingleSubstFormat2149   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 
serializeOT::SingleSubstFormat2164   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 
sanitizeOT::SingleSubstFormat2176   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 
193 struct SingleSubst
194 {
serializeOT::SingleSubst195   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 = 0;
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>
dispatchOT::SingleSubst223   inline typename context_t::return_t dispatch (context_t *c) const
224   {
225     TRACE_DISPATCH (this, u.format);
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 
sanitizeOT::SingleSubst233   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 
252 struct Sequence
253 {
closureOT::Sequence254   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 
collect_glyphsOT::Sequence262   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 
applyOT::Sequence270   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 
serializeOT::Sequence305   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 
sanitizeOT::Sequence315   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 
327 struct MultipleSubstFormat1
328 {
closureOT::MultipleSubstFormat1329   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 
collect_glyphsOT::MultipleSubstFormat1339   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 
get_coverageOT::MultipleSubstFormat1348   inline const Coverage &get_coverage (void) const
349   {
350     return this+coverage;
351   }
352 
would_applyOT::MultipleSubstFormat1353   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 
applyOT::MultipleSubstFormat1359   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 
serializeOT::MultipleSubstFormat1369   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 
sanitizeOT::MultipleSubstFormat1387   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 
404 struct MultipleSubst
405 {
serializeOT::MultipleSubst406   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>
dispatchOT::MultipleSubst423   inline typename context_t::return_t dispatch (context_t *c) const
424   {
425     TRACE_DISPATCH (this, u.format);
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 
sanitizeOT::MultipleSubst432   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 
449 typedef ArrayOf<GlyphID> AlternateSet;	/* Array of alternate GlyphIDs--in
450 					 * arbitrary order */
451 
452 struct AlternateSubstFormat1
453 {
closureOT::AlternateSubstFormat1454   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 
collect_glyphsOT::AlternateSubstFormat1468   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 
get_coverageOT::AlternateSubstFormat1481   inline const Coverage &get_coverage (void) const
482   {
483     return this+coverage;
484   }
485 
would_applyOT::AlternateSubstFormat1486   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 
applyOT::AlternateSubstFormat1492   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 
serializeOT::AlternateSubstFormat1520   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 
sanitizeOT::AlternateSubstFormat1538   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 
555 struct AlternateSubst
556 {
serializeOT::AlternateSubst557   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>
dispatchOT::AlternateSubst574   inline typename context_t::return_t dispatch (context_t *c) const
575   {
576     TRACE_DISPATCH (this, u.format);
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 
sanitizeOT::AlternateSubst583   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 
600 struct Ligature
601 {
closureOT::Ligature602   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 
collect_glyphsOT::Ligature612   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 
would_applyOT::Ligature621   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 
applyOT::Ligature634   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 
serializeOT::Ligature676   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:
sanitizeOT::Ligature689   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 
704 struct LigatureSet
705 {
closureOT::LigatureSet706   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 
collect_glyphsOT::LigatureSet714   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 
would_applyOT::LigatureSet722   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 
applyOT::LigatureSet735   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 
serializeOT::LigatureSet748   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 
sanitizeOT::LigatureSet767   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 
780 struct LigatureSubstFormat1
781 {
closureOT::LigatureSubstFormat1782   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 
collect_glyphsOT::LigatureSubstFormat1792   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 
get_coverageOT::LigatureSubstFormat1802   inline const Coverage &get_coverage (void) const
803   {
804     return this+coverage;
805   }
806 
would_applyOT::LigatureSubstFormat1807   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 
applyOT::LigatureSubstFormat1817   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 
serializeOT::LigatureSubstFormat1829   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 
sanitizeOT::LigatureSubstFormat1851   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 
868 struct LigatureSubst
869 {
serializeOT::LigatureSubst870   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>
dispatchOT::LigatureSubst890   inline typename context_t::return_t dispatch (context_t *c) const
891   {
892     TRACE_DISPATCH (this, u.format);
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 
sanitizeOT::LigatureSubst899   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 
916 struct ContextSubst : Context {};
917 
918 struct ChainContextSubst : ChainContext {};
919 
920 struct ExtensionSubst : Extension<ExtensionSubst>
921 {
922   typedef struct SubstLookupSubTable LookupSubTable;
923 
924   inline bool is_reverse (void) const;
925 };
926 
927 
928 struct ReverseChainSingleSubstFormat1
929 {
closureOT::ReverseChainSingleSubstFormat1930   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 
collect_glyphsOT::ReverseChainSingleSubstFormat1955   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 
get_coverageOT::ReverseChainSingleSubstFormat1979   inline const Coverage &get_coverage (void) const
980   {
981     return this+coverage;
982   }
983 
would_applyOT::ReverseChainSingleSubstFormat1984   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 
applyOT::ReverseChainSingleSubstFormat1990   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 
sanitizeOT::ReverseChainSingleSubstFormat11020   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 
1051 struct ReverseChainSingleSubst
1052 {
1053   template <typename context_t>
dispatchOT::ReverseChainSingleSubst1054   inline typename context_t::return_t dispatch (context_t *c) const
1055   {
1056     TRACE_DISPATCH (this, u.format);
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 
sanitizeOT::ReverseChainSingleSubst1063   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 
1085 struct 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>
dispatchOT::SubstLookupSubTable1101   inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
1102   {
1103     TRACE_DISPATCH (this, lookup_type);
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 
sanitizeOT::SubstLookupSubTable1117   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 
1153 struct SubstLookup : Lookup
1154 {
get_subtableOT::SubstLookup1155   inline const SubstLookupSubTable& get_subtable (unsigned int i) const
1156   { return this+CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i]; }
1157 
lookup_type_is_reverseOT::SubstLookup1158   inline static bool lookup_type_is_reverse (unsigned int lookup_type)
1159   { return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
1160 
is_reverseOT::SubstLookup1161   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 
closureOT::SubstLookup1169   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 
collect_glyphsOT::SubstLookup1176   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>
add_coverageOT::SubstLookup1184   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 
would_applyOT::SubstLookup1198   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 
apply_onceOT::SubstLookup1206   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 
serialize_subtableOT::SubstLookup1216   inline SubstLookupSubTable& serialize_subtable (hb_serialize_context_t *c,
1217 						  unsigned int i)
1218   { return CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i].serialize (c, this); }
1219 
serialize_singleOT::SubstLookup1220   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 
serialize_multipleOT::SubstLookup1231   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 
serialize_alternateOT::SubstLookup1244   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 
serialize_ligatureOT::SubstLookup1257   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>
dispatchOT::SubstLookup1276   inline typename context_t::return_t dispatch (context_t *c) const
1277   {
1278     unsigned int lookup_type = get_type ();
1279     TRACE_DISPATCH (this, lookup_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 
sanitizeOT::SubstLookup1289   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 
1311 typedef OffsetListOf<SubstLookup> SubstLookupList;
1312 
1313 /*
1314  * GSUB -- The Glyph Substitution Table
1315  */
1316 
1317 struct GSUB : GSUBGPOS
1318 {
1319   static const hb_tag_t tableTag	= HB_OT_TAG_GSUB;
1320 
get_lookupOT::GSUB1321   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 
sanitizeOT::GSUB1327   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 
1338 void
substitute_start(hb_font_t * font,hb_buffer_t * buffer)1339 GSUB::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 
1353 void
substitute_finish(hb_font_t * font HB_UNUSED,hb_buffer_t * buffer HB_UNUSED)1354 GSUB::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 
is_reverse(void) const1361 /*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 
1369 template <typename context_t>
dispatch_recurse_func(context_t * c,unsigned int lookup_index)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 
apply_recurse_func(hb_apply_context_t * c,unsigned int lookup_index)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