1 /*
2  * Copyright © 2007,2008,2009,2010  Red Hat, Inc.
3  * Copyright © 2010,2012  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_GSUBGPOS_PRIVATE_HH
30 #define HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH
31 
32 #include "hb-buffer-private.hh"
33 #include "hb-ot-layout-gdef-table.hh"
34 #include "hb-set-private.hh"
35 
36 
37 namespace OT {
38 
39 
40 
41 #define TRACE_DISPATCH(this, format) \
42 	hb_auto_trace_t<context_t::max_debug_depth, typename context_t::return_t> trace \
43 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
44 	 "format %d", (int) format);
45 
46 #ifndef HB_DEBUG_CLOSURE
47 #define HB_DEBUG_CLOSURE (HB_DEBUG+0)
48 #endif
49 
50 #define TRACE_CLOSURE(this) \
51 	hb_auto_trace_t<HB_DEBUG_CLOSURE, hb_void_t> trace \
52 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
53 	 "");
54 
55 struct hb_closure_context_t
56 {
get_nameOT::hb_closure_context_t57   inline const char *get_name (void) { return "CLOSURE"; }
58   static const unsigned int max_debug_depth = HB_DEBUG_CLOSURE;
59   typedef hb_void_t return_t;
60   typedef return_t (*recurse_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
61   template <typename T>
dispatchOT::hb_closure_context_t62   inline return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; }
default_return_valueOT::hb_closure_context_t63   static return_t default_return_value (void) { return HB_VOID; }
stop_sublookup_iterationOT::hb_closure_context_t64   bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
recurseOT::hb_closure_context_t65   return_t recurse (unsigned int lookup_index)
66   {
67     if (unlikely (nesting_level_left == 0 || !recurse_func))
68       return default_return_value ();
69 
70     nesting_level_left--;
71     recurse_func (this, lookup_index);
72     nesting_level_left++;
73     return HB_VOID;
74   }
75 
76   hb_face_t *face;
77   hb_set_t *glyphs;
78   recurse_func_t recurse_func;
79   unsigned int nesting_level_left;
80   unsigned int debug_depth;
81 
hb_closure_context_tOT::hb_closure_context_t82   hb_closure_context_t (hb_face_t *face_,
83 			hb_set_t *glyphs_,
84 		        unsigned int nesting_level_left_ = MAX_NESTING_LEVEL) :
85 			  face (face_),
86 			  glyphs (glyphs_),
87 			  recurse_func (NULL),
88 			  nesting_level_left (nesting_level_left_),
89 			  debug_depth (0) {}
90 
set_recurse_funcOT::hb_closure_context_t91   void set_recurse_func (recurse_func_t func) { recurse_func = func; }
92 };
93 
94 
95 
96 #ifndef HB_DEBUG_WOULD_APPLY
97 #define HB_DEBUG_WOULD_APPLY (HB_DEBUG+0)
98 #endif
99 
100 #define TRACE_WOULD_APPLY(this) \
101 	hb_auto_trace_t<HB_DEBUG_WOULD_APPLY, bool> trace \
102 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
103 	 "%d glyphs", c->len);
104 
105 struct hb_would_apply_context_t
106 {
get_nameOT::hb_would_apply_context_t107   inline const char *get_name (void) { return "WOULD_APPLY"; }
108   static const unsigned int max_debug_depth = HB_DEBUG_WOULD_APPLY;
109   typedef bool return_t;
110   template <typename T>
dispatchOT::hb_would_apply_context_t111   inline return_t dispatch (const T &obj) { return obj.would_apply (this); }
default_return_valueOT::hb_would_apply_context_t112   static return_t default_return_value (void) { return false; }
stop_sublookup_iterationOT::hb_would_apply_context_t113   bool stop_sublookup_iteration (return_t r) const { return r; }
114 
115   hb_face_t *face;
116   const hb_codepoint_t *glyphs;
117   unsigned int len;
118   bool zero_context;
119   unsigned int debug_depth;
120 
hb_would_apply_context_tOT::hb_would_apply_context_t121   hb_would_apply_context_t (hb_face_t *face_,
122 			    const hb_codepoint_t *glyphs_,
123 			    unsigned int len_,
124 			    bool zero_context_) :
125 			      face (face_),
126 			      glyphs (glyphs_),
127 			      len (len_),
128 			      zero_context (zero_context_),
129 			      debug_depth (0) {}
130 };
131 
132 
133 
134 #ifndef HB_DEBUG_COLLECT_GLYPHS
135 #define HB_DEBUG_COLLECT_GLYPHS (HB_DEBUG+0)
136 #endif
137 
138 #define TRACE_COLLECT_GLYPHS(this) \
139 	hb_auto_trace_t<HB_DEBUG_COLLECT_GLYPHS, hb_void_t> trace \
140 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
141 	 "");
142 
143 struct hb_collect_glyphs_context_t
144 {
get_nameOT::hb_collect_glyphs_context_t145   inline const char *get_name (void) { return "COLLECT_GLYPHS"; }
146   static const unsigned int max_debug_depth = HB_DEBUG_COLLECT_GLYPHS;
147   typedef hb_void_t return_t;
148   typedef return_t (*recurse_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
149   template <typename T>
dispatchOT::hb_collect_glyphs_context_t150   inline return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
default_return_valueOT::hb_collect_glyphs_context_t151   static return_t default_return_value (void) { return HB_VOID; }
stop_sublookup_iterationOT::hb_collect_glyphs_context_t152   bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
recurseOT::hb_collect_glyphs_context_t153   return_t recurse (unsigned int lookup_index)
154   {
155     if (unlikely (nesting_level_left == 0 || !recurse_func))
156       return default_return_value ();
157 
158     /* Note that GPOS sets recurse_func to NULL already, so it doesn't get
159      * past the previous check.  For GSUB, we only want to collect the output
160      * glyphs in the recursion.  If output is not requested, we can go home now.
161      *
162      * Note further, that the above is not exactly correct.  A recursed lookup
163      * is allowed to match input that is not matched in the context, but that's
164      * not how most fonts are built.  It's possible to relax that and recurse
165      * with all sets here if it proves to be an issue.
166      */
167 
168     if (output == hb_set_get_empty ())
169       return HB_VOID;
170 
171     /* Return if new lookup was recursed to before. */
172     if (recursed_lookups.has (lookup_index))
173       return HB_VOID;
174 
175     hb_set_t *old_before = before;
176     hb_set_t *old_input  = input;
177     hb_set_t *old_after  = after;
178     before = input = after = hb_set_get_empty ();
179 
180     nesting_level_left--;
181     recurse_func (this, lookup_index);
182     nesting_level_left++;
183 
184     before = old_before;
185     input  = old_input;
186     after  = old_after;
187 
188     recursed_lookups.add (lookup_index);
189 
190     return HB_VOID;
191   }
192 
193   hb_face_t *face;
194   hb_set_t *before;
195   hb_set_t *input;
196   hb_set_t *after;
197   hb_set_t *output;
198   recurse_func_t recurse_func;
199   hb_set_t recursed_lookups;
200   unsigned int nesting_level_left;
201   unsigned int debug_depth;
202 
hb_collect_glyphs_context_tOT::hb_collect_glyphs_context_t203   hb_collect_glyphs_context_t (hb_face_t *face_,
204 			       hb_set_t  *glyphs_before, /* OUT. May be NULL */
205 			       hb_set_t  *glyphs_input,  /* OUT. May be NULL */
206 			       hb_set_t  *glyphs_after,  /* OUT. May be NULL */
207 			       hb_set_t  *glyphs_output, /* OUT. May be NULL */
208 			       unsigned int nesting_level_left_ = MAX_NESTING_LEVEL) :
209 			      face (face_),
210 			      before (glyphs_before ? glyphs_before : hb_set_get_empty ()),
211 			      input  (glyphs_input  ? glyphs_input  : hb_set_get_empty ()),
212 			      after  (glyphs_after  ? glyphs_after  : hb_set_get_empty ()),
213 			      output (glyphs_output ? glyphs_output : hb_set_get_empty ()),
214 			      recurse_func (NULL),
215 			      recursed_lookups (),
216 			      nesting_level_left (nesting_level_left_),
217 			      debug_depth (0)
218   {
219     recursed_lookups.init ();
220   }
~hb_collect_glyphs_context_tOT::hb_collect_glyphs_context_t221   ~hb_collect_glyphs_context_t (void)
222   {
223     recursed_lookups.fini ();
224   }
225 
set_recurse_funcOT::hb_collect_glyphs_context_t226   void set_recurse_func (recurse_func_t func) { recurse_func = func; }
227 };
228 
229 
230 
231 #ifndef HB_DEBUG_GET_COVERAGE
232 #define HB_DEBUG_GET_COVERAGE (HB_DEBUG+0)
233 #endif
234 
235 struct hb_get_coverage_context_t
236 {
get_nameOT::hb_get_coverage_context_t237   inline const char *get_name (void) { return "GET_COVERAGE"; }
238   static const unsigned int max_debug_depth = HB_DEBUG_GET_COVERAGE;
239   typedef const Coverage &return_t;
240   template <typename T>
dispatchOT::hb_get_coverage_context_t241   inline return_t dispatch (const T &obj) { return obj.get_coverage (); }
default_return_valueOT::hb_get_coverage_context_t242   static return_t default_return_value (void) { return Null(Coverage); }
243 
hb_get_coverage_context_tOT::hb_get_coverage_context_t244   hb_get_coverage_context_t (void) :
245 			    debug_depth (0) {}
246 
247   unsigned int debug_depth;
248 };
249 
250 
251 
252 #ifndef HB_DEBUG_APPLY
253 #define HB_DEBUG_APPLY (HB_DEBUG+0)
254 #endif
255 
256 #define TRACE_APPLY(this) \
257 	hb_auto_trace_t<HB_DEBUG_APPLY, bool> trace \
258 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
259 	 "idx %d codepoint %u", c->buffer->idx, c->buffer->cur().codepoint);
260 
261 struct hb_apply_context_t
262 {
get_nameOT::hb_apply_context_t263   inline const char *get_name (void) { return "APPLY"; }
264   static const unsigned int max_debug_depth = HB_DEBUG_APPLY;
265   typedef bool return_t;
266   typedef return_t (*recurse_func_t) (hb_apply_context_t *c, unsigned int lookup_index);
267   template <typename T>
dispatchOT::hb_apply_context_t268   inline return_t dispatch (const T &obj) { return obj.apply (this); }
default_return_valueOT::hb_apply_context_t269   static return_t default_return_value (void) { return false; }
stop_sublookup_iterationOT::hb_apply_context_t270   bool stop_sublookup_iteration (return_t r) const { return r; }
recurseOT::hb_apply_context_t271   return_t recurse (unsigned int lookup_index)
272   {
273     if (unlikely (nesting_level_left == 0 || !recurse_func))
274       return default_return_value ();
275 
276     nesting_level_left--;
277     bool ret = recurse_func (this, lookup_index);
278     nesting_level_left++;
279     return ret;
280   }
281 
282   unsigned int table_index; /* GSUB/GPOS */
283   hb_font_t *font;
284   hb_face_t *face;
285   hb_buffer_t *buffer;
286   hb_direction_t direction;
287   hb_mask_t lookup_mask;
288   bool auto_zwj;
289   recurse_func_t recurse_func;
290   unsigned int nesting_level_left;
291   unsigned int lookup_props;
292   const GDEF &gdef;
293   bool has_glyph_classes;
294   unsigned int debug_depth;
295 
296 
hb_apply_context_tOT::hb_apply_context_t297   hb_apply_context_t (unsigned int table_index_,
298 		      hb_font_t *font_,
299 		      hb_buffer_t *buffer_) :
300 			table_index (table_index_),
301 			font (font_), face (font->face), buffer (buffer_),
302 			direction (buffer_->props.direction),
303 			lookup_mask (1),
304 			auto_zwj (true),
305 			recurse_func (NULL),
306 			nesting_level_left (MAX_NESTING_LEVEL),
307 			lookup_props (0),
308 			gdef (*hb_ot_layout_from_face (face)->gdef),
309 			has_glyph_classes (gdef.has_glyph_classes ()),
310 			debug_depth (0) {}
311 
set_lookup_maskOT::hb_apply_context_t312   inline void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; }
set_auto_zwjOT::hb_apply_context_t313   inline void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; }
set_recurse_funcOT::hb_apply_context_t314   inline void set_recurse_func (recurse_func_t func) { recurse_func = func; }
set_lookup_propsOT::hb_apply_context_t315   inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
set_lookupOT::hb_apply_context_t316   inline void set_lookup (const Lookup &l) { lookup_props = l.get_props (); }
317 
318   struct matcher_t
319   {
matcher_tOT::hb_apply_context_t::matcher_t320     inline matcher_t (void) :
321 	     lookup_props (0),
322 	     ignore_zwnj (false),
323 	     ignore_zwj (false),
324 	     mask (-1),
325 #define arg1(arg) (arg) /* Remove the macro to see why it's needed! */
326 	     syllable arg1(0),
327 #undef arg1
328 	     match_func (NULL),
329 	     match_data (NULL) {};
330 
331     typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
332 
set_ignore_zwnjOT::hb_apply_context_t::matcher_t333     inline void set_ignore_zwnj (bool ignore_zwnj_) { ignore_zwnj = ignore_zwnj_; }
set_ignore_zwjOT::hb_apply_context_t::matcher_t334     inline void set_ignore_zwj (bool ignore_zwj_) { ignore_zwj = ignore_zwj_; }
set_lookup_propsOT::hb_apply_context_t::matcher_t335     inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
set_maskOT::hb_apply_context_t::matcher_t336     inline void set_mask (hb_mask_t mask_) { mask = mask_; }
set_syllableOT::hb_apply_context_t::matcher_t337     inline void set_syllable (uint8_t syllable_)  { syllable = syllable_; }
set_match_funcOT::hb_apply_context_t::matcher_t338     inline void set_match_func (match_func_t match_func_,
339 				const void *match_data_)
340     { match_func = match_func_; match_data = match_data_; }
341 
342     enum may_match_t {
343       MATCH_NO,
344       MATCH_YES,
345       MATCH_MAYBE
346     };
347 
may_matchOT::hb_apply_context_t::matcher_t348     inline may_match_t may_match (const hb_glyph_info_t &info,
349 				  const USHORT          *glyph_data) const
350     {
351       if (!(info.mask & mask) ||
352 	  (syllable && syllable != info.syllable ()))
353 	return MATCH_NO;
354 
355       if (match_func)
356         return match_func (info.codepoint, *glyph_data, match_data) ? MATCH_YES : MATCH_NO;
357 
358       return MATCH_MAYBE;
359     }
360 
361     enum may_skip_t {
362       SKIP_NO,
363       SKIP_YES,
364       SKIP_MAYBE
365     };
366 
367     inline may_skip_t
may_skipOT::hb_apply_context_t::matcher_t368     may_skip (const hb_apply_context_t *c,
369 	      const hb_glyph_info_t    &info) const
370     {
371       if (!c->check_glyph_property (&info, lookup_props))
372 	return SKIP_YES;
373 
374       if (unlikely (_hb_glyph_info_is_default_ignorable (&info) &&
375 		    (ignore_zwnj || !_hb_glyph_info_is_zwnj (&info)) &&
376 		    (ignore_zwj || !_hb_glyph_info_is_zwj (&info)) &&
377 		    !_hb_glyph_info_ligated (&info)))
378 	return SKIP_MAYBE;
379 
380       return SKIP_NO;
381     }
382 
383     protected:
384     unsigned int lookup_props;
385     bool ignore_zwnj;
386     bool ignore_zwj;
387     hb_mask_t mask;
388     uint8_t syllable;
389     match_func_t match_func;
390     const void *match_data;
391   };
392 
393   struct skipping_forward_iterator_t
394   {
skipping_forward_iterator_tOT::hb_apply_context_t::skipping_forward_iterator_t395     inline skipping_forward_iterator_t (hb_apply_context_t *c_,
396 					unsigned int start_index_,
397 					unsigned int num_items_,
398 					bool context_match = false) :
399 					 idx (start_index_),
400 					 c (c_),
401 					 match_glyph_data (NULL),
402 					 num_items (num_items_),
403 					 end (c->buffer->len)
404     {
405       matcher.set_lookup_props (c->lookup_props);
406       /* Ignore ZWNJ if we are matching GSUB context, or matching GPOS. */
407       matcher.set_ignore_zwnj (context_match || c->table_index == 1);
408       /* Ignore ZWJ if we are matching GSUB context, or matching GPOS, or if asked to. */
409       matcher.set_ignore_zwj (context_match || c->table_index == 1 || c->auto_zwj);
410       if (!context_match)
411 	matcher.set_mask (c->lookup_mask);
412       matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
413     }
set_lookup_propsOT::hb_apply_context_t::skipping_forward_iterator_t414     inline void set_lookup_props (unsigned int lookup_props) { matcher.set_lookup_props (lookup_props); }
set_syllableOT::hb_apply_context_t::skipping_forward_iterator_t415     inline void set_syllable (unsigned int syllable) { matcher.set_syllable (syllable); }
set_match_funcOT::hb_apply_context_t::skipping_forward_iterator_t416     inline void set_match_func (matcher_t::match_func_t match_func,
417 				const void *match_data,
418 				const USHORT glyph_data[])
419     {
420       matcher.set_match_func (match_func, match_data);
421       match_glyph_data = glyph_data;
422     }
423 
has_no_chanceOT::hb_apply_context_t::skipping_forward_iterator_t424     inline bool has_no_chance (void) const { return unlikely (num_items && idx + num_items >= end); }
rejectOT::hb_apply_context_t::skipping_forward_iterator_t425     inline void reject (void) { num_items++; match_glyph_data--; }
nextOT::hb_apply_context_t::skipping_forward_iterator_t426     inline bool next (void)
427     {
428       assert (num_items > 0);
429       while (!has_no_chance ())
430       {
431 	idx++;
432 	const hb_glyph_info_t &info = c->buffer->info[idx];
433 
434 	matcher_t::may_skip_t skip = matcher.may_skip (c, info);
435 	if (unlikely (skip == matcher_t::SKIP_YES))
436 	  continue;
437 
438 	matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
439 	if (match == matcher_t::MATCH_YES ||
440 	    (match == matcher_t::MATCH_MAYBE &&
441 	     skip == matcher_t::SKIP_NO))
442 	{
443 	  num_items--;
444 	  match_glyph_data++;
445 	  return true;
446 	}
447 
448 	if (skip == matcher_t::SKIP_NO)
449 	  return false;
450       }
451       return false;
452     }
453 
454     unsigned int idx;
455     protected:
456     hb_apply_context_t *c;
457     matcher_t matcher;
458     const USHORT *match_glyph_data;
459 
460     unsigned int num_items;
461     unsigned int end;
462   };
463 
464   struct skipping_backward_iterator_t
465   {
skipping_backward_iterator_tOT::hb_apply_context_t::skipping_backward_iterator_t466     inline skipping_backward_iterator_t (hb_apply_context_t *c_,
467 					 unsigned int start_index_,
468 					 unsigned int num_items_,
469 					 bool context_match = false) :
470 					  idx (start_index_),
471 					  c (c_),
472 					  match_glyph_data (NULL),
473 					  num_items (num_items_)
474     {
475       matcher.set_lookup_props (c->lookup_props);
476       /* Ignore ZWNJ if we are matching GSUB context, or matching GPOS. */
477       matcher.set_ignore_zwnj (context_match || c->table_index == 1);
478       /* Ignore ZWJ if we are matching GSUB context, or matching GPOS, or if asked to. */
479       matcher.set_ignore_zwj (context_match || c->table_index == 1 || c->auto_zwj);
480       if (!context_match)
481 	matcher.set_mask (c->lookup_mask);
482       matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
483     }
set_lookup_propsOT::hb_apply_context_t::skipping_backward_iterator_t484     inline void set_lookup_props (unsigned int lookup_props) { matcher.set_lookup_props (lookup_props); }
set_syllableOT::hb_apply_context_t::skipping_backward_iterator_t485     inline void set_syllable (unsigned int syllable) { matcher.set_syllable (syllable); }
set_match_funcOT::hb_apply_context_t::skipping_backward_iterator_t486     inline void set_match_func (matcher_t::match_func_t match_func,
487 				const void *match_data,
488 				const USHORT glyph_data[])
489     {
490       matcher.set_match_func (match_func, match_data);
491       match_glyph_data = glyph_data;
492     }
493 
has_no_chanceOT::hb_apply_context_t::skipping_backward_iterator_t494     inline bool has_no_chance (void) const { return unlikely (idx < num_items); }
rejectOT::hb_apply_context_t::skipping_backward_iterator_t495     inline void reject (void) { num_items++; }
prevOT::hb_apply_context_t::skipping_backward_iterator_t496     inline bool prev (void)
497     {
498       assert (num_items > 0);
499       while (!has_no_chance ())
500       {
501 	idx--;
502 	const hb_glyph_info_t &info = c->buffer->out_info[idx];
503 
504 	matcher_t::may_skip_t skip = matcher.may_skip (c, info);
505 	if (unlikely (skip == matcher_t::SKIP_YES))
506 	  continue;
507 
508 	matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
509 	if (match == matcher_t::MATCH_YES ||
510 	    (match == matcher_t::MATCH_MAYBE &&
511 	     skip == matcher_t::SKIP_NO))
512 	{
513 	  num_items--;
514 	  match_glyph_data++;
515 	  return true;
516 	}
517 
518 	if (skip == matcher_t::SKIP_NO)
519 	  return false;
520       }
521       return false;
522     }
523 
524     unsigned int idx;
525     protected:
526     hb_apply_context_t *c;
527     matcher_t matcher;
528     const USHORT *match_glyph_data;
529 
530     unsigned int num_items;
531   };
532 
533   inline bool
match_properties_markOT::hb_apply_context_t534   match_properties_mark (hb_codepoint_t  glyph,
535 			 unsigned int    glyph_props,
536 			 unsigned int    lookup_props) const
537   {
538     /* If using mark filtering sets, the high short of
539      * lookup_props has the set index.
540      */
541     if (lookup_props & LookupFlag::UseMarkFilteringSet)
542       return gdef.mark_set_covers (lookup_props >> 16, glyph);
543 
544     /* The second byte of lookup_props has the meaning
545      * "ignore marks of attachment type different than
546      * the attachment type specified."
547      */
548     if (lookup_props & LookupFlag::MarkAttachmentType)
549       return (lookup_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType);
550 
551     return true;
552   }
553 
554   inline bool
check_glyph_propertyOT::hb_apply_context_t555   check_glyph_property (const hb_glyph_info_t *info,
556 			unsigned int  lookup_props) const
557   {
558     hb_codepoint_t glyph = info->codepoint;
559     unsigned int glyph_props = _hb_glyph_info_get_glyph_props (info);
560 
561     /* Not covered, if, for example, glyph class is ligature and
562      * lookup_props includes LookupFlags::IgnoreLigatures
563      */
564     if (glyph_props & lookup_props & LookupFlag::IgnoreFlags)
565       return false;
566 
567     if (unlikely (glyph_props & HB_OT_LAYOUT_GLYPH_PROPS_MARK))
568       return match_properties_mark (glyph, glyph_props, lookup_props);
569 
570     return true;
571   }
572 
_set_glyph_propsOT::hb_apply_context_t573   inline void _set_glyph_props (hb_codepoint_t glyph_index,
574 			  unsigned int class_guess = 0,
575 			  bool ligature = false,
576 			  bool component = false) const
577   {
578     unsigned int add_in = _hb_glyph_info_get_glyph_props (&buffer->cur()) &
579 			  HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE;
580     add_in |= HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED;
581     if (ligature)
582     {
583       add_in |= HB_OT_LAYOUT_GLYPH_PROPS_LIGATED;
584       /* In the only place that the MULTIPLIED bit is used, Uniscribe
585        * seems to only care about the "last" transformation between
586        * Ligature and Multiple substitions.  Ie. if you ligate, expand,
587        * and ligate again, it forgives the multiplication and acts as
588        * if only ligation happened.  As such, clear MULTIPLIED bit.
589        */
590       add_in &= ~HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
591     }
592     if (component)
593       add_in |= HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
594     if (likely (has_glyph_classes))
595       _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | gdef.get_glyph_props (glyph_index));
596     else if (class_guess)
597       _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | class_guess);
598   }
599 
replace_glyphOT::hb_apply_context_t600   inline void replace_glyph (hb_codepoint_t glyph_index) const
601   {
602     _set_glyph_props (glyph_index);
603     buffer->replace_glyph (glyph_index);
604   }
replace_glyph_inplaceOT::hb_apply_context_t605   inline void replace_glyph_inplace (hb_codepoint_t glyph_index) const
606   {
607     _set_glyph_props (glyph_index);
608     buffer->cur().codepoint = glyph_index;
609   }
replace_glyph_with_ligatureOT::hb_apply_context_t610   inline void replace_glyph_with_ligature (hb_codepoint_t glyph_index,
611 					   unsigned int class_guess) const
612   {
613     _set_glyph_props (glyph_index, class_guess, true);
614     buffer->replace_glyph (glyph_index);
615   }
output_glyph_for_componentOT::hb_apply_context_t616   inline void output_glyph_for_component (hb_codepoint_t glyph_index,
617 					  unsigned int class_guess) const
618   {
619     _set_glyph_props (glyph_index, class_guess, false, true);
620     buffer->output_glyph (glyph_index);
621   }
622 };
623 
624 
625 
626 typedef bool (*intersects_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
627 typedef void (*collect_glyphs_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
628 typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
629 
630 struct ContextClosureFuncs
631 {
632   intersects_func_t intersects;
633 };
634 struct ContextCollectGlyphsFuncs
635 {
636   collect_glyphs_func_t collect;
637 };
638 struct ContextApplyFuncs
639 {
640   match_func_t match;
641 };
642 
643 
intersects_glyph(hb_set_t * glyphs,const USHORT & value,const void * data HB_UNUSED)644 static inline bool intersects_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
645 {
646   return glyphs->has (value);
647 }
intersects_class(hb_set_t * glyphs,const USHORT & value,const void * data)648 static inline bool intersects_class (hb_set_t *glyphs, const USHORT &value, const void *data)
649 {
650   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
651   return class_def.intersects_class (glyphs, value);
652 }
intersects_coverage(hb_set_t * glyphs,const USHORT & value,const void * data)653 static inline bool intersects_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
654 {
655   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
656   return (data+coverage).intersects (glyphs);
657 }
658 
intersects_array(hb_closure_context_t * c,unsigned int count,const USHORT values[],intersects_func_t intersects_func,const void * intersects_data)659 static inline bool intersects_array (hb_closure_context_t *c,
660 				     unsigned int count,
661 				     const USHORT values[],
662 				     intersects_func_t intersects_func,
663 				     const void *intersects_data)
664 {
665   for (unsigned int i = 0; i < count; i++)
666     if (likely (!intersects_func (c->glyphs, values[i], intersects_data)))
667       return false;
668   return true;
669 }
670 
671 
collect_glyph(hb_set_t * glyphs,const USHORT & value,const void * data HB_UNUSED)672 static inline void collect_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
673 {
674   glyphs->add (value);
675 }
collect_class(hb_set_t * glyphs,const USHORT & value,const void * data)676 static inline void collect_class (hb_set_t *glyphs, const USHORT &value, const void *data)
677 {
678   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
679   class_def.add_class (glyphs, value);
680 }
collect_coverage(hb_set_t * glyphs,const USHORT & value,const void * data)681 static inline void collect_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
682 {
683   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
684   (data+coverage).add_coverage (glyphs);
685 }
collect_array(hb_collect_glyphs_context_t * c HB_UNUSED,hb_set_t * glyphs,unsigned int count,const USHORT values[],collect_glyphs_func_t collect_func,const void * collect_data)686 static inline void collect_array (hb_collect_glyphs_context_t *c HB_UNUSED,
687 				  hb_set_t *glyphs,
688 				  unsigned int count,
689 				  const USHORT values[],
690 				  collect_glyphs_func_t collect_func,
691 				  const void *collect_data)
692 {
693   for (unsigned int i = 0; i < count; i++)
694     collect_func (glyphs, values[i], collect_data);
695 }
696 
697 
match_glyph(hb_codepoint_t glyph_id,const USHORT & value,const void * data HB_UNUSED)698 static inline bool match_glyph (hb_codepoint_t glyph_id, const USHORT &value, const void *data HB_UNUSED)
699 {
700   return glyph_id == value;
701 }
match_class(hb_codepoint_t glyph_id,const USHORT & value,const void * data)702 static inline bool match_class (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
703 {
704   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
705   return class_def.get_class (glyph_id) == value;
706 }
match_coverage(hb_codepoint_t glyph_id,const USHORT & value,const void * data)707 static inline bool match_coverage (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
708 {
709   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
710   return (data+coverage).get_coverage (glyph_id) != NOT_COVERED;
711 }
712 
would_match_input(hb_would_apply_context_t * c,unsigned int count,const USHORT input[],match_func_t match_func,const void * match_data)713 static inline bool would_match_input (hb_would_apply_context_t *c,
714 				      unsigned int count, /* Including the first glyph (not matched) */
715 				      const USHORT input[], /* Array of input values--start with second glyph */
716 				      match_func_t match_func,
717 				      const void *match_data)
718 {
719   if (count != c->len)
720     return false;
721 
722   for (unsigned int i = 1; i < count; i++)
723     if (likely (!match_func (c->glyphs[i], input[i - 1], match_data)))
724       return false;
725 
726   return true;
727 }
match_input(hb_apply_context_t * c,unsigned int count,const USHORT input[],match_func_t match_func,const void * match_data,unsigned int * end_offset,unsigned int match_positions[MAX_CONTEXT_LENGTH],bool * p_is_mark_ligature=NULL,unsigned int * p_total_component_count=NULL)728 static inline bool match_input (hb_apply_context_t *c,
729 				unsigned int count, /* Including the first glyph (not matched) */
730 				const USHORT input[], /* Array of input values--start with second glyph */
731 				match_func_t match_func,
732 				const void *match_data,
733 				unsigned int *end_offset,
734 				unsigned int match_positions[MAX_CONTEXT_LENGTH],
735 				bool *p_is_mark_ligature = NULL,
736 				unsigned int *p_total_component_count = NULL)
737 {
738   TRACE_APPLY (NULL);
739 
740   if (unlikely (count > MAX_CONTEXT_LENGTH)) TRACE_RETURN (false);
741 
742   hb_buffer_t *buffer = c->buffer;
743 
744   hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, buffer->idx, count - 1);
745   skippy_iter.set_match_func (match_func, match_data, input);
746   if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
747 
748   /*
749    * This is perhaps the trickiest part of OpenType...  Remarks:
750    *
751    * - If all components of the ligature were marks, we call this a mark ligature.
752    *
753    * - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize
754    *   it as a ligature glyph.
755    *
756    * - Ligatures cannot be formed across glyphs attached to different components
757    *   of previous ligatures.  Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and
758    *   LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother.
759    *   However, it would be wrong to ligate that SHADDA,FATHA sequence.o
760    *   There is an exception to this: If a ligature tries ligating with marks that
761    *   belong to it itself, go ahead, assuming that the font designer knows what
762    *   they are doing (otherwise it can break Indic stuff when a matra wants to
763    *   ligate with a conjunct...)
764    */
765 
766   bool is_mark_ligature = _hb_glyph_info_is_mark (&buffer->cur());
767 
768   unsigned int total_component_count = 0;
769   total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->cur());
770 
771   unsigned int first_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
772   unsigned int first_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
773 
774   match_positions[0] = buffer->idx;
775   for (unsigned int i = 1; i < count; i++)
776   {
777     if (!skippy_iter.next ()) return TRACE_RETURN (false);
778 
779     match_positions[i] = skippy_iter.idx;
780 
781     unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx]);
782     unsigned int this_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]);
783 
784     if (first_lig_id && first_lig_comp) {
785       /* If first component was attached to a previous ligature component,
786        * all subsequent components should be attached to the same ligature
787        * component, otherwise we shouldn't ligate them. */
788       if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp)
789 	return TRACE_RETURN (false);
790     } else {
791       /* If first component was NOT attached to a previous ligature component,
792        * all subsequent components should also NOT be attached to any ligature
793        * component, unless they are attached to the first component itself! */
794       if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id))
795 	return TRACE_RETURN (false);
796     }
797 
798     is_mark_ligature = is_mark_ligature && _hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx]);
799     total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->info[skippy_iter.idx]);
800   }
801 
802   *end_offset = skippy_iter.idx - buffer->idx + 1;
803 
804   if (p_is_mark_ligature)
805     *p_is_mark_ligature = is_mark_ligature;
806 
807   if (p_total_component_count)
808     *p_total_component_count = total_component_count;
809 
810   return TRACE_RETURN (true);
811 }
ligate_input(hb_apply_context_t * c,unsigned int count,unsigned int match_positions[MAX_CONTEXT_LENGTH],unsigned int match_length,hb_codepoint_t lig_glyph,bool is_mark_ligature,unsigned int total_component_count)812 static inline void ligate_input (hb_apply_context_t *c,
813 				 unsigned int count, /* Including the first glyph */
814 				 unsigned int match_positions[MAX_CONTEXT_LENGTH], /* Including the first glyph */
815 				 unsigned int match_length,
816 				 hb_codepoint_t lig_glyph,
817 				 bool is_mark_ligature,
818 				 unsigned int total_component_count)
819 {
820   TRACE_APPLY (NULL);
821 
822   hb_buffer_t *buffer = c->buffer;
823 
824   buffer->merge_clusters (buffer->idx, buffer->idx + match_length);
825 
826   /*
827    * - If it *is* a mark ligature, we don't allocate a new ligature id, and leave
828    *   the ligature to keep its old ligature id.  This will allow it to attach to
829    *   a base ligature in GPOS.  Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH,
830    *   and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA wit a
831    *   ligature id and component value of 2.  Then if SHADDA,FATHA form a ligature
832    *   later, we don't want them to lose their ligature id/component, otherwise
833    *   GPOS will fail to correctly position the mark ligature on top of the
834    *   LAM,LAM,HEH ligature.  See:
835    *     https://bugzilla.gnome.org/show_bug.cgi?id=676343
836    *
837    * - If a ligature is formed of components that some of which are also ligatures
838    *   themselves, and those ligature components had marks attached to *their*
839    *   components, we have to attach the marks to the new ligature component
840    *   positions!  Now *that*'s tricky!  And these marks may be following the
841    *   last component of the whole sequence, so we should loop forward looking
842    *   for them and update them.
843    *
844    *   Eg. the sequence is LAM,LAM,SHADDA,FATHA,HEH, and the font first forms a
845    *   'calt' ligature of LAM,HEH, leaving the SHADDA and FATHA with a ligature
846    *   id and component == 1.  Now, during 'liga', the LAM and the LAM-HEH ligature
847    *   form a LAM-LAM-HEH ligature.  We need to reassign the SHADDA and FATHA to
848    *   the new ligature with a component value of 2.
849    *
850    *   This in fact happened to a font...  See:
851    *   https://bugzilla.gnome.org/show_bug.cgi?id=437633
852    */
853 
854   unsigned int klass = is_mark_ligature ? 0 : HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE;
855   unsigned int lig_id = is_mark_ligature ? 0 : _hb_allocate_lig_id (buffer);
856   unsigned int last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
857   unsigned int last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
858   unsigned int components_so_far = last_num_components;
859 
860   if (!is_mark_ligature)
861   {
862     _hb_glyph_info_set_lig_props_for_ligature (&buffer->cur(), lig_id, total_component_count);
863     if (_hb_glyph_info_get_general_category (&buffer->cur()) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
864     {
865       _hb_glyph_info_set_general_category (&buffer->cur(), HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER);
866       _hb_glyph_info_set_modified_combining_class (&buffer->cur(), 0);
867     }
868   }
869   c->replace_glyph_with_ligature (lig_glyph, klass);
870 
871   for (unsigned int i = 1; i < count; i++)
872   {
873     while (buffer->idx < match_positions[i])
874     {
875       if (!is_mark_ligature) {
876 	unsigned int new_lig_comp = components_so_far - last_num_components +
877 				    MIN (MAX (_hb_glyph_info_get_lig_comp (&buffer->cur()), 1u), last_num_components);
878 	_hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp);
879       }
880       buffer->next_glyph ();
881     }
882 
883     last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
884     last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
885     components_so_far += last_num_components;
886 
887     /* Skip the base glyph */
888     buffer->idx++;
889   }
890 
891   if (!is_mark_ligature && last_lig_id) {
892     /* Re-adjust components for any marks following. */
893     for (unsigned int i = buffer->idx; i < buffer->len; i++) {
894       if (last_lig_id == _hb_glyph_info_get_lig_id (&buffer->info[i])) {
895 	unsigned int new_lig_comp = components_so_far - last_num_components +
896 				    MIN (MAX (_hb_glyph_info_get_lig_comp (&buffer->info[i]), 1u), last_num_components);
897 	_hb_glyph_info_set_lig_props_for_mark (&buffer->info[i], lig_id, new_lig_comp);
898       } else
899 	break;
900     }
901   }
902   TRACE_RETURN (true);
903 }
904 
match_backtrack(hb_apply_context_t * c,unsigned int count,const USHORT backtrack[],match_func_t match_func,const void * match_data)905 static inline bool match_backtrack (hb_apply_context_t *c,
906 				    unsigned int count,
907 				    const USHORT backtrack[],
908 				    match_func_t match_func,
909 				    const void *match_data)
910 {
911   TRACE_APPLY (NULL);
912 
913   hb_apply_context_t::skipping_backward_iterator_t skippy_iter (c, c->buffer->backtrack_len (), count, true);
914   skippy_iter.set_match_func (match_func, match_data, backtrack);
915   if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
916 
917   for (unsigned int i = 0; i < count; i++)
918     if (!skippy_iter.prev ())
919       return TRACE_RETURN (false);
920 
921   return TRACE_RETURN (true);
922 }
923 
match_lookahead(hb_apply_context_t * c,unsigned int count,const USHORT lookahead[],match_func_t match_func,const void * match_data,unsigned int offset)924 static inline bool match_lookahead (hb_apply_context_t *c,
925 				    unsigned int count,
926 				    const USHORT lookahead[],
927 				    match_func_t match_func,
928 				    const void *match_data,
929 				    unsigned int offset)
930 {
931   TRACE_APPLY (NULL);
932 
933   hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, c->buffer->idx + offset - 1, count, true);
934   skippy_iter.set_match_func (match_func, match_data, lookahead);
935   if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
936 
937   for (unsigned int i = 0; i < count; i++)
938     if (!skippy_iter.next ())
939       return TRACE_RETURN (false);
940 
941   return TRACE_RETURN (true);
942 }
943 
944 
945 
946 struct LookupRecord
947 {
sanitizeOT::LookupRecord948   inline bool sanitize (hb_sanitize_context_t *c) {
949     TRACE_SANITIZE (this);
950     return TRACE_RETURN (c->check_struct (this));
951   }
952 
953   USHORT	sequenceIndex;		/* Index into current glyph
954 					 * sequence--first glyph = 0 */
955   USHORT	lookupListIndex;	/* Lookup to apply to that
956 					 * position--zero--based */
957   public:
958   DEFINE_SIZE_STATIC (4);
959 };
960 
961 
962 template <typename context_t>
recurse_lookups(context_t * c,unsigned int lookupCount,const LookupRecord lookupRecord[])963 static inline void recurse_lookups (context_t *c,
964 				    unsigned int lookupCount,
965 				    const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
966 {
967   for (unsigned int i = 0; i < lookupCount; i++)
968     c->recurse (lookupRecord[i].lookupListIndex);
969 }
970 
apply_lookup(hb_apply_context_t * c,unsigned int count,unsigned int match_positions[MAX_CONTEXT_LENGTH],unsigned int lookupCount,const LookupRecord lookupRecord[],unsigned int match_length)971 static inline bool apply_lookup (hb_apply_context_t *c,
972 				 unsigned int count, /* Including the first glyph */
973 				 unsigned int match_positions[MAX_CONTEXT_LENGTH], /* Including the first glyph */
974 				 unsigned int lookupCount,
975 				 const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */
976 				 unsigned int match_length)
977 {
978   TRACE_APPLY (NULL);
979 
980   hb_buffer_t *buffer = c->buffer;
981   unsigned int end;
982 
983   /* All positions are distance from beginning of *output* buffer.
984    * Adjust. */
985   {
986     unsigned int bl = buffer->backtrack_len ();
987     end = bl + match_length;
988 
989     int delta = bl - buffer->idx;
990     /* Convert positions to new indexing. */
991     for (unsigned int j = 0; j < count; j++)
992       match_positions[j] += delta;
993   }
994 
995   for (unsigned int i = 0; i < lookupCount; i++)
996   {
997     unsigned int idx = lookupRecord[i].sequenceIndex;
998     if (idx >= count)
999       continue;
1000 
1001     buffer->move_to (match_positions[idx]);
1002 
1003     unsigned int orig_len = buffer->backtrack_len () + buffer->lookahead_len ();
1004     if (!c->recurse (lookupRecord[i].lookupListIndex))
1005       continue;
1006 
1007     unsigned int new_len = buffer->backtrack_len () + buffer->lookahead_len ();
1008     int delta = new_len - orig_len;
1009 
1010     if (!delta)
1011         continue;
1012 
1013     /* Recursed lookup changed buffer len.  Adjust. */
1014 
1015     /* end can't go back past the current match position.
1016      * Note: this is only true because we do NOT allow MultipleSubst
1017      * with zero sequence len. */
1018     end = MAX ((int) match_positions[idx] + 1, int (end) + delta);
1019 
1020     unsigned int next = idx + 1; /* next now is the position after the recursed lookup. */
1021 
1022     if (delta > 0)
1023     {
1024       if (unlikely (delta + count > MAX_CONTEXT_LENGTH))
1025 	break;
1026     }
1027     else
1028     {
1029       /* NOTE: delta is negative. */
1030       delta = MAX (delta, (int) next - (int) count);
1031       next -= delta;
1032     }
1033 
1034     /* Shift! */
1035     memmove (match_positions + next + delta, match_positions + next,
1036 	     (count - next) * sizeof (match_positions[0]));
1037     next += delta;
1038     count += delta;
1039 
1040     /* Fill in new entries. */
1041     for (unsigned int j = idx + 1; j < next; j++)
1042       match_positions[j] = match_positions[j - 1] + 1;
1043 
1044     /* And fixup the rest. */
1045     for (; next < count; next++)
1046       match_positions[next] += delta;
1047   }
1048 
1049   buffer->move_to (end);
1050 
1051   return TRACE_RETURN (true);
1052 }
1053 
1054 
1055 
1056 /* Contextual lookups */
1057 
1058 struct ContextClosureLookupContext
1059 {
1060   ContextClosureFuncs funcs;
1061   const void *intersects_data;
1062 };
1063 
1064 struct ContextCollectGlyphsLookupContext
1065 {
1066   ContextCollectGlyphsFuncs funcs;
1067   const void *collect_data;
1068 };
1069 
1070 struct ContextApplyLookupContext
1071 {
1072   ContextApplyFuncs funcs;
1073   const void *match_data;
1074 };
1075 
context_closure_lookup(hb_closure_context_t * c,unsigned int inputCount,const USHORT input[],unsigned int lookupCount,const LookupRecord lookupRecord[],ContextClosureLookupContext & lookup_context)1076 static inline void context_closure_lookup (hb_closure_context_t *c,
1077 					   unsigned int inputCount, /* Including the first glyph (not matched) */
1078 					   const USHORT input[], /* Array of input values--start with second glyph */
1079 					   unsigned int lookupCount,
1080 					   const LookupRecord lookupRecord[],
1081 					   ContextClosureLookupContext &lookup_context)
1082 {
1083   if (intersects_array (c,
1084 			inputCount ? inputCount - 1 : 0, input,
1085 			lookup_context.funcs.intersects, lookup_context.intersects_data))
1086     recurse_lookups (c,
1087 		     lookupCount, lookupRecord);
1088 }
1089 
context_collect_glyphs_lookup(hb_collect_glyphs_context_t * c,unsigned int inputCount,const USHORT input[],unsigned int lookupCount,const LookupRecord lookupRecord[],ContextCollectGlyphsLookupContext & lookup_context)1090 static inline void context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1091 						  unsigned int inputCount, /* Including the first glyph (not matched) */
1092 						  const USHORT input[], /* Array of input values--start with second glyph */
1093 						  unsigned int lookupCount,
1094 						  const LookupRecord lookupRecord[],
1095 						  ContextCollectGlyphsLookupContext &lookup_context)
1096 {
1097   collect_array (c, c->input,
1098 		 inputCount ? inputCount - 1 : 0, input,
1099 		 lookup_context.funcs.collect, lookup_context.collect_data);
1100   recurse_lookups (c,
1101 		   lookupCount, lookupRecord);
1102 }
1103 
context_would_apply_lookup(hb_would_apply_context_t * c,unsigned int inputCount,const USHORT input[],unsigned int lookupCount HB_UNUSED,const LookupRecord lookupRecord[]HB_UNUSED,ContextApplyLookupContext & lookup_context)1104 static inline bool context_would_apply_lookup (hb_would_apply_context_t *c,
1105 					       unsigned int inputCount, /* Including the first glyph (not matched) */
1106 					       const USHORT input[], /* Array of input values--start with second glyph */
1107 					       unsigned int lookupCount HB_UNUSED,
1108 					       const LookupRecord lookupRecord[] HB_UNUSED,
1109 					       ContextApplyLookupContext &lookup_context)
1110 {
1111   return would_match_input (c,
1112 			    inputCount, input,
1113 			    lookup_context.funcs.match, lookup_context.match_data);
1114 }
context_apply_lookup(hb_apply_context_t * c,unsigned int inputCount,const USHORT input[],unsigned int lookupCount,const LookupRecord lookupRecord[],ContextApplyLookupContext & lookup_context)1115 static inline bool context_apply_lookup (hb_apply_context_t *c,
1116 					 unsigned int inputCount, /* Including the first glyph (not matched) */
1117 					 const USHORT input[], /* Array of input values--start with second glyph */
1118 					 unsigned int lookupCount,
1119 					 const LookupRecord lookupRecord[],
1120 					 ContextApplyLookupContext &lookup_context)
1121 {
1122   unsigned int match_length = 0;
1123   unsigned int match_positions[MAX_CONTEXT_LENGTH];
1124   return match_input (c,
1125 		      inputCount, input,
1126 		      lookup_context.funcs.match, lookup_context.match_data,
1127 		      &match_length, match_positions)
1128       && apply_lookup (c,
1129 		       inputCount, match_positions,
1130 		       lookupCount, lookupRecord,
1131 		       match_length);
1132 }
1133 
1134 struct Rule
1135 {
closureOT::Rule1136   inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1137   {
1138     TRACE_CLOSURE (this);
1139     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1140     context_closure_lookup (c,
1141 			    inputCount, inputZ,
1142 			    lookupCount, lookupRecord,
1143 			    lookup_context);
1144   }
1145 
collect_glyphsOT::Rule1146   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1147   {
1148     TRACE_COLLECT_GLYPHS (this);
1149     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1150     context_collect_glyphs_lookup (c,
1151 				   inputCount, inputZ,
1152 				   lookupCount, lookupRecord,
1153 				   lookup_context);
1154   }
1155 
would_applyOT::Rule1156   inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1157   {
1158     TRACE_WOULD_APPLY (this);
1159     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1160     return TRACE_RETURN (context_would_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1161   }
1162 
applyOT::Rule1163   inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1164   {
1165     TRACE_APPLY (this);
1166     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1167     return TRACE_RETURN (context_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1168   }
1169 
1170   public:
sanitizeOT::Rule1171   inline bool sanitize (hb_sanitize_context_t *c) {
1172     TRACE_SANITIZE (this);
1173     return inputCount.sanitize (c)
1174 	&& lookupCount.sanitize (c)
1175 	&& c->check_range (inputZ,
1176 			   inputZ[0].static_size * inputCount
1177 			   + lookupRecordX[0].static_size * lookupCount);
1178   }
1179 
1180   protected:
1181   USHORT	inputCount;		/* Total number of glyphs in input
1182 					 * glyph sequence--includes the first
1183 					 * glyph */
1184   USHORT	lookupCount;		/* Number of LookupRecords */
1185   USHORT	inputZ[VAR];		/* Array of match inputs--start with
1186 					 * second glyph */
1187   LookupRecord	lookupRecordX[VAR];	/* Array of LookupRecords--in
1188 					 * design order */
1189   public:
1190   DEFINE_SIZE_ARRAY2 (4, inputZ, lookupRecordX);
1191 };
1192 
1193 struct RuleSet
1194 {
closureOT::RuleSet1195   inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1196   {
1197     TRACE_CLOSURE (this);
1198     unsigned int num_rules = rule.len;
1199     for (unsigned int i = 0; i < num_rules; i++)
1200       (this+rule[i]).closure (c, lookup_context);
1201   }
1202 
collect_glyphsOT::RuleSet1203   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1204   {
1205     TRACE_COLLECT_GLYPHS (this);
1206     unsigned int num_rules = rule.len;
1207     for (unsigned int i = 0; i < num_rules; i++)
1208       (this+rule[i]).collect_glyphs (c, lookup_context);
1209   }
1210 
would_applyOT::RuleSet1211   inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1212   {
1213     TRACE_WOULD_APPLY (this);
1214     unsigned int num_rules = rule.len;
1215     for (unsigned int i = 0; i < num_rules; i++)
1216     {
1217       if ((this+rule[i]).would_apply (c, lookup_context))
1218         return TRACE_RETURN (true);
1219     }
1220     return TRACE_RETURN (false);
1221   }
1222 
applyOT::RuleSet1223   inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1224   {
1225     TRACE_APPLY (this);
1226     unsigned int num_rules = rule.len;
1227     for (unsigned int i = 0; i < num_rules; i++)
1228     {
1229       if ((this+rule[i]).apply (c, lookup_context))
1230         return TRACE_RETURN (true);
1231     }
1232     return TRACE_RETURN (false);
1233   }
1234 
sanitizeOT::RuleSet1235   inline bool sanitize (hb_sanitize_context_t *c) {
1236     TRACE_SANITIZE (this);
1237     return TRACE_RETURN (rule.sanitize (c, this));
1238   }
1239 
1240   protected:
1241   OffsetArrayOf<Rule>
1242 		rule;			/* Array of Rule tables
1243 					 * ordered by preference */
1244   public:
1245   DEFINE_SIZE_ARRAY (2, rule);
1246 };
1247 
1248 
1249 struct ContextFormat1
1250 {
closureOT::ContextFormat11251   inline void closure (hb_closure_context_t *c) const
1252   {
1253     TRACE_CLOSURE (this);
1254 
1255     const Coverage &cov = (this+coverage);
1256 
1257     struct ContextClosureLookupContext lookup_context = {
1258       {intersects_glyph},
1259       NULL
1260     };
1261 
1262     unsigned int count = ruleSet.len;
1263     for (unsigned int i = 0; i < count; i++)
1264       if (cov.intersects_coverage (c->glyphs, i)) {
1265 	const RuleSet &rule_set = this+ruleSet[i];
1266 	rule_set.closure (c, lookup_context);
1267       }
1268   }
1269 
collect_glyphsOT::ContextFormat11270   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1271   {
1272     TRACE_COLLECT_GLYPHS (this);
1273     (this+coverage).add_coverage (c->input);
1274 
1275     struct ContextCollectGlyphsLookupContext lookup_context = {
1276       {collect_glyph},
1277       NULL
1278     };
1279 
1280     unsigned int count = ruleSet.len;
1281     for (unsigned int i = 0; i < count; i++)
1282       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1283   }
1284 
would_applyOT::ContextFormat11285   inline bool would_apply (hb_would_apply_context_t *c) const
1286   {
1287     TRACE_WOULD_APPLY (this);
1288 
1289     const RuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1290     struct ContextApplyLookupContext lookup_context = {
1291       {match_glyph},
1292       NULL
1293     };
1294     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
1295   }
1296 
get_coverageOT::ContextFormat11297   inline const Coverage &get_coverage (void) const
1298   {
1299     return this+coverage;
1300   }
1301 
applyOT::ContextFormat11302   inline bool apply (hb_apply_context_t *c) const
1303   {
1304     TRACE_APPLY (this);
1305     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1306     if (likely (index == NOT_COVERED))
1307       return TRACE_RETURN (false);
1308 
1309     const RuleSet &rule_set = this+ruleSet[index];
1310     struct ContextApplyLookupContext lookup_context = {
1311       {match_glyph},
1312       NULL
1313     };
1314     return TRACE_RETURN (rule_set.apply (c, lookup_context));
1315   }
1316 
sanitizeOT::ContextFormat11317   inline bool sanitize (hb_sanitize_context_t *c) {
1318     TRACE_SANITIZE (this);
1319     return TRACE_RETURN (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1320   }
1321 
1322   protected:
1323   USHORT	format;			/* Format identifier--format = 1 */
1324   OffsetTo<Coverage>
1325 		coverage;		/* Offset to Coverage table--from
1326 					 * beginning of table */
1327   OffsetArrayOf<RuleSet>
1328 		ruleSet;		/* Array of RuleSet tables
1329 					 * ordered by Coverage Index */
1330   public:
1331   DEFINE_SIZE_ARRAY (6, ruleSet);
1332 };
1333 
1334 
1335 struct ContextFormat2
1336 {
closureOT::ContextFormat21337   inline void closure (hb_closure_context_t *c) const
1338   {
1339     TRACE_CLOSURE (this);
1340     if (!(this+coverage).intersects (c->glyphs))
1341       return;
1342 
1343     const ClassDef &class_def = this+classDef;
1344 
1345     struct ContextClosureLookupContext lookup_context = {
1346       {intersects_class},
1347       &class_def
1348     };
1349 
1350     unsigned int count = ruleSet.len;
1351     for (unsigned int i = 0; i < count; i++)
1352       if (class_def.intersects_class (c->glyphs, i)) {
1353 	const RuleSet &rule_set = this+ruleSet[i];
1354 	rule_set.closure (c, lookup_context);
1355       }
1356   }
1357 
collect_glyphsOT::ContextFormat21358   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1359   {
1360     TRACE_COLLECT_GLYPHS (this);
1361     (this+coverage).add_coverage (c->input);
1362 
1363     const ClassDef &class_def = this+classDef;
1364     struct ContextCollectGlyphsLookupContext lookup_context = {
1365       {collect_class},
1366       &class_def
1367     };
1368 
1369     unsigned int count = ruleSet.len;
1370     for (unsigned int i = 0; i < count; i++)
1371       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1372   }
1373 
would_applyOT::ContextFormat21374   inline bool would_apply (hb_would_apply_context_t *c) const
1375   {
1376     TRACE_WOULD_APPLY (this);
1377 
1378     const ClassDef &class_def = this+classDef;
1379     unsigned int index = class_def.get_class (c->glyphs[0]);
1380     const RuleSet &rule_set = this+ruleSet[index];
1381     struct ContextApplyLookupContext lookup_context = {
1382       {match_class},
1383       &class_def
1384     };
1385     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
1386   }
1387 
get_coverageOT::ContextFormat21388   inline const Coverage &get_coverage (void) const
1389   {
1390     return this+coverage;
1391   }
1392 
applyOT::ContextFormat21393   inline bool apply (hb_apply_context_t *c) const
1394   {
1395     TRACE_APPLY (this);
1396     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1397     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
1398 
1399     const ClassDef &class_def = this+classDef;
1400     index = class_def.get_class (c->buffer->cur().codepoint);
1401     const RuleSet &rule_set = this+ruleSet[index];
1402     struct ContextApplyLookupContext lookup_context = {
1403       {match_class},
1404       &class_def
1405     };
1406     return TRACE_RETURN (rule_set.apply (c, lookup_context));
1407   }
1408 
sanitizeOT::ContextFormat21409   inline bool sanitize (hb_sanitize_context_t *c) {
1410     TRACE_SANITIZE (this);
1411     return TRACE_RETURN (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this));
1412   }
1413 
1414   protected:
1415   USHORT	format;			/* Format identifier--format = 2 */
1416   OffsetTo<Coverage>
1417 		coverage;		/* Offset to Coverage table--from
1418 					 * beginning of table */
1419   OffsetTo<ClassDef>
1420 		classDef;		/* Offset to glyph ClassDef table--from
1421 					 * beginning of table */
1422   OffsetArrayOf<RuleSet>
1423 		ruleSet;		/* Array of RuleSet tables
1424 					 * ordered by class */
1425   public:
1426   DEFINE_SIZE_ARRAY (8, ruleSet);
1427 };
1428 
1429 
1430 struct ContextFormat3
1431 {
closureOT::ContextFormat31432   inline void closure (hb_closure_context_t *c) const
1433   {
1434     TRACE_CLOSURE (this);
1435     if (!(this+coverageZ[0]).intersects (c->glyphs))
1436       return;
1437 
1438     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1439     struct ContextClosureLookupContext lookup_context = {
1440       {intersects_coverage},
1441       this
1442     };
1443     context_closure_lookup (c,
1444 			    glyphCount, (const USHORT *) (coverageZ + 1),
1445 			    lookupCount, lookupRecord,
1446 			    lookup_context);
1447   }
1448 
collect_glyphsOT::ContextFormat31449   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1450   {
1451     TRACE_COLLECT_GLYPHS (this);
1452     (this+coverageZ[0]).add_coverage (c->input);
1453 
1454     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1455     struct ContextCollectGlyphsLookupContext lookup_context = {
1456       {collect_coverage},
1457       this
1458     };
1459 
1460     context_collect_glyphs_lookup (c,
1461 				   glyphCount, (const USHORT *) (coverageZ + 1),
1462 				   lookupCount, lookupRecord,
1463 				   lookup_context);
1464   }
1465 
would_applyOT::ContextFormat31466   inline bool would_apply (hb_would_apply_context_t *c) const
1467   {
1468     TRACE_WOULD_APPLY (this);
1469 
1470     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1471     struct ContextApplyLookupContext lookup_context = {
1472       {match_coverage},
1473       this
1474     };
1475     return TRACE_RETURN (context_would_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1476   }
1477 
get_coverageOT::ContextFormat31478   inline const Coverage &get_coverage (void) const
1479   {
1480     return this+coverageZ[0];
1481   }
1482 
applyOT::ContextFormat31483   inline bool apply (hb_apply_context_t *c) const
1484   {
1485     TRACE_APPLY (this);
1486     unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint);
1487     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
1488 
1489     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1490     struct ContextApplyLookupContext lookup_context = {
1491       {match_coverage},
1492       this
1493     };
1494     return TRACE_RETURN (context_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1495   }
1496 
sanitizeOT::ContextFormat31497   inline bool sanitize (hb_sanitize_context_t *c) {
1498     TRACE_SANITIZE (this);
1499     if (!c->check_struct (this)) return TRACE_RETURN (false);
1500     unsigned int count = glyphCount;
1501     if (!count) return TRACE_RETURN (false); /* We want to access coverageZ[0] freely. */
1502     if (!c->check_array (coverageZ, coverageZ[0].static_size, count)) return TRACE_RETURN (false);
1503     for (unsigned int i = 0; i < count; i++)
1504       if (!coverageZ[i].sanitize (c, this)) return TRACE_RETURN (false);
1505     LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * count);
1506     return TRACE_RETURN (c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount));
1507   }
1508 
1509   protected:
1510   USHORT	format;			/* Format identifier--format = 3 */
1511   USHORT	glyphCount;		/* Number of glyphs in the input glyph
1512 					 * sequence */
1513   USHORT	lookupCount;		/* Number of LookupRecords */
1514   OffsetTo<Coverage>
1515 		coverageZ[VAR];		/* Array of offsets to Coverage
1516 					 * table in glyph sequence order */
1517   LookupRecord	lookupRecordX[VAR];	/* Array of LookupRecords--in
1518 					 * design order */
1519   public:
1520   DEFINE_SIZE_ARRAY2 (6, coverageZ, lookupRecordX);
1521 };
1522 
1523 struct Context
1524 {
1525   template <typename context_t>
dispatchOT::Context1526   inline typename context_t::return_t dispatch (context_t *c) const
1527   {
1528     TRACE_DISPATCH (this, u.format);
1529     switch (u.format) {
1530     case 1: return TRACE_RETURN (c->dispatch (u.format1));
1531     case 2: return TRACE_RETURN (c->dispatch (u.format2));
1532     case 3: return TRACE_RETURN (c->dispatch (u.format3));
1533     default:return TRACE_RETURN (c->default_return_value ());
1534     }
1535   }
1536 
sanitizeOT::Context1537   inline bool sanitize (hb_sanitize_context_t *c) {
1538     TRACE_SANITIZE (this);
1539     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
1540     switch (u.format) {
1541     case 1: return TRACE_RETURN (u.format1.sanitize (c));
1542     case 2: return TRACE_RETURN (u.format2.sanitize (c));
1543     case 3: return TRACE_RETURN (u.format3.sanitize (c));
1544     default:return TRACE_RETURN (true);
1545     }
1546   }
1547 
1548   protected:
1549   union {
1550   USHORT		format;		/* Format identifier */
1551   ContextFormat1	format1;
1552   ContextFormat2	format2;
1553   ContextFormat3	format3;
1554   } u;
1555 };
1556 
1557 
1558 /* Chaining Contextual lookups */
1559 
1560 struct ChainContextClosureLookupContext
1561 {
1562   ContextClosureFuncs funcs;
1563   const void *intersects_data[3];
1564 };
1565 
1566 struct ChainContextCollectGlyphsLookupContext
1567 {
1568   ContextCollectGlyphsFuncs funcs;
1569   const void *collect_data[3];
1570 };
1571 
1572 struct ChainContextApplyLookupContext
1573 {
1574   ContextApplyFuncs funcs;
1575   const void *match_data[3];
1576 };
1577 
chain_context_closure_lookup(hb_closure_context_t * c,unsigned int backtrackCount,const USHORT backtrack[],unsigned int inputCount,const USHORT input[],unsigned int lookaheadCount,const USHORT lookahead[],unsigned int lookupCount,const LookupRecord lookupRecord[],ChainContextClosureLookupContext & lookup_context)1578 static inline void chain_context_closure_lookup (hb_closure_context_t *c,
1579 						 unsigned int backtrackCount,
1580 						 const USHORT backtrack[],
1581 						 unsigned int inputCount, /* Including the first glyph (not matched) */
1582 						 const USHORT input[], /* Array of input values--start with second glyph */
1583 						 unsigned int lookaheadCount,
1584 						 const USHORT lookahead[],
1585 						 unsigned int lookupCount,
1586 						 const LookupRecord lookupRecord[],
1587 						 ChainContextClosureLookupContext &lookup_context)
1588 {
1589   if (intersects_array (c,
1590 			backtrackCount, backtrack,
1591 			lookup_context.funcs.intersects, lookup_context.intersects_data[0])
1592    && intersects_array (c,
1593 			inputCount ? inputCount - 1 : 0, input,
1594 			lookup_context.funcs.intersects, lookup_context.intersects_data[1])
1595    && intersects_array (c,
1596 		       lookaheadCount, lookahead,
1597 		       lookup_context.funcs.intersects, lookup_context.intersects_data[2]))
1598     recurse_lookups (c,
1599 		     lookupCount, lookupRecord);
1600 }
1601 
chain_context_collect_glyphs_lookup(hb_collect_glyphs_context_t * c,unsigned int backtrackCount,const USHORT backtrack[],unsigned int inputCount,const USHORT input[],unsigned int lookaheadCount,const USHORT lookahead[],unsigned int lookupCount,const LookupRecord lookupRecord[],ChainContextCollectGlyphsLookupContext & lookup_context)1602 static inline void chain_context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1603 						        unsigned int backtrackCount,
1604 						        const USHORT backtrack[],
1605 						        unsigned int inputCount, /* Including the first glyph (not matched) */
1606 						        const USHORT input[], /* Array of input values--start with second glyph */
1607 						        unsigned int lookaheadCount,
1608 						        const USHORT lookahead[],
1609 						        unsigned int lookupCount,
1610 						        const LookupRecord lookupRecord[],
1611 						        ChainContextCollectGlyphsLookupContext &lookup_context)
1612 {
1613   collect_array (c, c->before,
1614 		 backtrackCount, backtrack,
1615 		 lookup_context.funcs.collect, lookup_context.collect_data[0]);
1616   collect_array (c, c->input,
1617 		 inputCount ? inputCount - 1 : 0, input,
1618 		 lookup_context.funcs.collect, lookup_context.collect_data[1]);
1619   collect_array (c, c->after,
1620 		 lookaheadCount, lookahead,
1621 		 lookup_context.funcs.collect, lookup_context.collect_data[2]);
1622   recurse_lookups (c,
1623 		   lookupCount, lookupRecord);
1624 }
1625 
chain_context_would_apply_lookup(hb_would_apply_context_t * c,unsigned int backtrackCount,const USHORT backtrack[]HB_UNUSED,unsigned int inputCount,const USHORT input[],unsigned int lookaheadCount,const USHORT lookahead[]HB_UNUSED,unsigned int lookupCount HB_UNUSED,const LookupRecord lookupRecord[]HB_UNUSED,ChainContextApplyLookupContext & lookup_context)1626 static inline bool chain_context_would_apply_lookup (hb_would_apply_context_t *c,
1627 						     unsigned int backtrackCount,
1628 						     const USHORT backtrack[] HB_UNUSED,
1629 						     unsigned int inputCount, /* Including the first glyph (not matched) */
1630 						     const USHORT input[], /* Array of input values--start with second glyph */
1631 						     unsigned int lookaheadCount,
1632 						     const USHORT lookahead[] HB_UNUSED,
1633 						     unsigned int lookupCount HB_UNUSED,
1634 						     const LookupRecord lookupRecord[] HB_UNUSED,
1635 						     ChainContextApplyLookupContext &lookup_context)
1636 {
1637   return (c->zero_context ? !backtrackCount && !lookaheadCount : true)
1638       && would_match_input (c,
1639 			    inputCount, input,
1640 			    lookup_context.funcs.match, lookup_context.match_data[1]);
1641 }
1642 
chain_context_apply_lookup(hb_apply_context_t * c,unsigned int backtrackCount,const USHORT backtrack[],unsigned int inputCount,const USHORT input[],unsigned int lookaheadCount,const USHORT lookahead[],unsigned int lookupCount,const LookupRecord lookupRecord[],ChainContextApplyLookupContext & lookup_context)1643 static inline bool chain_context_apply_lookup (hb_apply_context_t *c,
1644 					       unsigned int backtrackCount,
1645 					       const USHORT backtrack[],
1646 					       unsigned int inputCount, /* Including the first glyph (not matched) */
1647 					       const USHORT input[], /* Array of input values--start with second glyph */
1648 					       unsigned int lookaheadCount,
1649 					       const USHORT lookahead[],
1650 					       unsigned int lookupCount,
1651 					       const LookupRecord lookupRecord[],
1652 					       ChainContextApplyLookupContext &lookup_context)
1653 {
1654   unsigned int match_length = 0;
1655   unsigned int match_positions[MAX_CONTEXT_LENGTH];
1656   return match_input (c,
1657 		      inputCount, input,
1658 		      lookup_context.funcs.match, lookup_context.match_data[1],
1659 		      &match_length, match_positions)
1660       && match_backtrack (c,
1661 			  backtrackCount, backtrack,
1662 			  lookup_context.funcs.match, lookup_context.match_data[0])
1663       && match_lookahead (c,
1664 			  lookaheadCount, lookahead,
1665 			  lookup_context.funcs.match, lookup_context.match_data[2],
1666 			  match_length)
1667       && apply_lookup (c,
1668 		       inputCount, match_positions,
1669 		       lookupCount, lookupRecord,
1670 		       match_length);
1671 }
1672 
1673 struct ChainRule
1674 {
closureOT::ChainRule1675   inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1676   {
1677     TRACE_CLOSURE (this);
1678     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1679     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1680     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1681     chain_context_closure_lookup (c,
1682 				  backtrack.len, backtrack.array,
1683 				  input.len, input.array,
1684 				  lookahead.len, lookahead.array,
1685 				  lookup.len, lookup.array,
1686 				  lookup_context);
1687   }
1688 
collect_glyphsOT::ChainRule1689   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1690   {
1691     TRACE_COLLECT_GLYPHS (this);
1692     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1693     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1694     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1695     chain_context_collect_glyphs_lookup (c,
1696 					 backtrack.len, backtrack.array,
1697 					 input.len, input.array,
1698 					 lookahead.len, lookahead.array,
1699 					 lookup.len, lookup.array,
1700 					 lookup_context);
1701   }
1702 
would_applyOT::ChainRule1703   inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1704   {
1705     TRACE_WOULD_APPLY (this);
1706     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1707     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1708     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1709     return TRACE_RETURN (chain_context_would_apply_lookup (c,
1710 							   backtrack.len, backtrack.array,
1711 							   input.len, input.array,
1712 							   lookahead.len, lookahead.array, lookup.len,
1713 							   lookup.array, lookup_context));
1714   }
1715 
applyOT::ChainRule1716   inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1717   {
1718     TRACE_APPLY (this);
1719     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1720     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1721     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1722     return TRACE_RETURN (chain_context_apply_lookup (c,
1723 						     backtrack.len, backtrack.array,
1724 						     input.len, input.array,
1725 						     lookahead.len, lookahead.array, lookup.len,
1726 						     lookup.array, lookup_context));
1727   }
1728 
sanitizeOT::ChainRule1729   inline bool sanitize (hb_sanitize_context_t *c) {
1730     TRACE_SANITIZE (this);
1731     if (!backtrack.sanitize (c)) return TRACE_RETURN (false);
1732     HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1733     if (!input.sanitize (c)) return TRACE_RETURN (false);
1734     ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1735     if (!lookahead.sanitize (c)) return TRACE_RETURN (false);
1736     ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1737     return TRACE_RETURN (lookup.sanitize (c));
1738   }
1739 
1740   protected:
1741   ArrayOf<USHORT>
1742 		backtrack;		/* Array of backtracking values
1743 					 * (to be matched before the input
1744 					 * sequence) */
1745   HeadlessArrayOf<USHORT>
1746 		inputX;			/* Array of input values (start with
1747 					 * second glyph) */
1748   ArrayOf<USHORT>
1749 		lookaheadX;		/* Array of lookahead values's (to be
1750 					 * matched after the input sequence) */
1751   ArrayOf<LookupRecord>
1752 		lookupX;		/* Array of LookupRecords--in
1753 					 * design order) */
1754   public:
1755   DEFINE_SIZE_MIN (8);
1756 };
1757 
1758 struct ChainRuleSet
1759 {
closureOT::ChainRuleSet1760   inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1761   {
1762     TRACE_CLOSURE (this);
1763     unsigned int num_rules = rule.len;
1764     for (unsigned int i = 0; i < num_rules; i++)
1765       (this+rule[i]).closure (c, lookup_context);
1766   }
1767 
collect_glyphsOT::ChainRuleSet1768   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1769   {
1770     TRACE_COLLECT_GLYPHS (this);
1771     unsigned int num_rules = rule.len;
1772     for (unsigned int i = 0; i < num_rules; i++)
1773       (this+rule[i]).collect_glyphs (c, lookup_context);
1774   }
1775 
would_applyOT::ChainRuleSet1776   inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1777   {
1778     TRACE_WOULD_APPLY (this);
1779     unsigned int num_rules = rule.len;
1780     for (unsigned int i = 0; i < num_rules; i++)
1781       if ((this+rule[i]).would_apply (c, lookup_context))
1782         return TRACE_RETURN (true);
1783 
1784     return TRACE_RETURN (false);
1785   }
1786 
applyOT::ChainRuleSet1787   inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1788   {
1789     TRACE_APPLY (this);
1790     unsigned int num_rules = rule.len;
1791     for (unsigned int i = 0; i < num_rules; i++)
1792       if ((this+rule[i]).apply (c, lookup_context))
1793         return TRACE_RETURN (true);
1794 
1795     return TRACE_RETURN (false);
1796   }
1797 
sanitizeOT::ChainRuleSet1798   inline bool sanitize (hb_sanitize_context_t *c) {
1799     TRACE_SANITIZE (this);
1800     return TRACE_RETURN (rule.sanitize (c, this));
1801   }
1802 
1803   protected:
1804   OffsetArrayOf<ChainRule>
1805 		rule;			/* Array of ChainRule tables
1806 					 * ordered by preference */
1807   public:
1808   DEFINE_SIZE_ARRAY (2, rule);
1809 };
1810 
1811 struct ChainContextFormat1
1812 {
closureOT::ChainContextFormat11813   inline void closure (hb_closure_context_t *c) const
1814   {
1815     TRACE_CLOSURE (this);
1816     const Coverage &cov = (this+coverage);
1817 
1818     struct ChainContextClosureLookupContext lookup_context = {
1819       {intersects_glyph},
1820       {NULL, NULL, NULL}
1821     };
1822 
1823     unsigned int count = ruleSet.len;
1824     for (unsigned int i = 0; i < count; i++)
1825       if (cov.intersects_coverage (c->glyphs, i)) {
1826 	const ChainRuleSet &rule_set = this+ruleSet[i];
1827 	rule_set.closure (c, lookup_context);
1828       }
1829   }
1830 
collect_glyphsOT::ChainContextFormat11831   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1832   {
1833     TRACE_COLLECT_GLYPHS (this);
1834     (this+coverage).add_coverage (c->input);
1835 
1836     struct ChainContextCollectGlyphsLookupContext lookup_context = {
1837       {collect_glyph},
1838       {NULL, NULL, NULL}
1839     };
1840 
1841     unsigned int count = ruleSet.len;
1842     for (unsigned int i = 0; i < count; i++)
1843       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1844   }
1845 
would_applyOT::ChainContextFormat11846   inline bool would_apply (hb_would_apply_context_t *c) const
1847   {
1848     TRACE_WOULD_APPLY (this);
1849 
1850     const ChainRuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1851     struct ChainContextApplyLookupContext lookup_context = {
1852       {match_glyph},
1853       {NULL, NULL, NULL}
1854     };
1855     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
1856   }
1857 
get_coverageOT::ChainContextFormat11858   inline const Coverage &get_coverage (void) const
1859   {
1860     return this+coverage;
1861   }
1862 
applyOT::ChainContextFormat11863   inline bool apply (hb_apply_context_t *c) const
1864   {
1865     TRACE_APPLY (this);
1866     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1867     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
1868 
1869     const ChainRuleSet &rule_set = this+ruleSet[index];
1870     struct ChainContextApplyLookupContext lookup_context = {
1871       {match_glyph},
1872       {NULL, NULL, NULL}
1873     };
1874     return TRACE_RETURN (rule_set.apply (c, lookup_context));
1875   }
1876 
sanitizeOT::ChainContextFormat11877   inline bool sanitize (hb_sanitize_context_t *c) {
1878     TRACE_SANITIZE (this);
1879     return TRACE_RETURN (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1880   }
1881 
1882   protected:
1883   USHORT	format;			/* Format identifier--format = 1 */
1884   OffsetTo<Coverage>
1885 		coverage;		/* Offset to Coverage table--from
1886 					 * beginning of table */
1887   OffsetArrayOf<ChainRuleSet>
1888 		ruleSet;		/* Array of ChainRuleSet tables
1889 					 * ordered by Coverage Index */
1890   public:
1891   DEFINE_SIZE_ARRAY (6, ruleSet);
1892 };
1893 
1894 struct ChainContextFormat2
1895 {
closureOT::ChainContextFormat21896   inline void closure (hb_closure_context_t *c) const
1897   {
1898     TRACE_CLOSURE (this);
1899     if (!(this+coverage).intersects (c->glyphs))
1900       return;
1901 
1902     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1903     const ClassDef &input_class_def = this+inputClassDef;
1904     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1905 
1906     struct ChainContextClosureLookupContext lookup_context = {
1907       {intersects_class},
1908       {&backtrack_class_def,
1909        &input_class_def,
1910        &lookahead_class_def}
1911     };
1912 
1913     unsigned int count = ruleSet.len;
1914     for (unsigned int i = 0; i < count; i++)
1915       if (input_class_def.intersects_class (c->glyphs, i)) {
1916 	const ChainRuleSet &rule_set = this+ruleSet[i];
1917 	rule_set.closure (c, lookup_context);
1918       }
1919   }
1920 
collect_glyphsOT::ChainContextFormat21921   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1922   {
1923     TRACE_COLLECT_GLYPHS (this);
1924     (this+coverage).add_coverage (c->input);
1925 
1926     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1927     const ClassDef &input_class_def = this+inputClassDef;
1928     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1929 
1930     struct ChainContextCollectGlyphsLookupContext lookup_context = {
1931       {collect_class},
1932       {&backtrack_class_def,
1933        &input_class_def,
1934        &lookahead_class_def}
1935     };
1936 
1937     unsigned int count = ruleSet.len;
1938     for (unsigned int i = 0; i < count; i++)
1939       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1940   }
1941 
would_applyOT::ChainContextFormat21942   inline bool would_apply (hb_would_apply_context_t *c) const
1943   {
1944     TRACE_WOULD_APPLY (this);
1945 
1946     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1947     const ClassDef &input_class_def = this+inputClassDef;
1948     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1949 
1950     unsigned int index = input_class_def.get_class (c->glyphs[0]);
1951     const ChainRuleSet &rule_set = this+ruleSet[index];
1952     struct ChainContextApplyLookupContext lookup_context = {
1953       {match_class},
1954       {&backtrack_class_def,
1955        &input_class_def,
1956        &lookahead_class_def}
1957     };
1958     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
1959   }
1960 
get_coverageOT::ChainContextFormat21961   inline const Coverage &get_coverage (void) const
1962   {
1963     return this+coverage;
1964   }
1965 
applyOT::ChainContextFormat21966   inline bool apply (hb_apply_context_t *c) const
1967   {
1968     TRACE_APPLY (this);
1969     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1970     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
1971 
1972     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1973     const ClassDef &input_class_def = this+inputClassDef;
1974     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1975 
1976     index = input_class_def.get_class (c->buffer->cur().codepoint);
1977     const ChainRuleSet &rule_set = this+ruleSet[index];
1978     struct ChainContextApplyLookupContext lookup_context = {
1979       {match_class},
1980       {&backtrack_class_def,
1981        &input_class_def,
1982        &lookahead_class_def}
1983     };
1984     return TRACE_RETURN (rule_set.apply (c, lookup_context));
1985   }
1986 
sanitizeOT::ChainContextFormat21987   inline bool sanitize (hb_sanitize_context_t *c) {
1988     TRACE_SANITIZE (this);
1989     return TRACE_RETURN (coverage.sanitize (c, this) && backtrackClassDef.sanitize (c, this) &&
1990 			 inputClassDef.sanitize (c, this) && lookaheadClassDef.sanitize (c, this) &&
1991 			 ruleSet.sanitize (c, this));
1992   }
1993 
1994   protected:
1995   USHORT	format;			/* Format identifier--format = 2 */
1996   OffsetTo<Coverage>
1997 		coverage;		/* Offset to Coverage table--from
1998 					 * beginning of table */
1999   OffsetTo<ClassDef>
2000 		backtrackClassDef;	/* Offset to glyph ClassDef table
2001 					 * containing backtrack sequence
2002 					 * data--from beginning of table */
2003   OffsetTo<ClassDef>
2004 		inputClassDef;		/* Offset to glyph ClassDef
2005 					 * table containing input sequence
2006 					 * data--from beginning of table */
2007   OffsetTo<ClassDef>
2008 		lookaheadClassDef;	/* Offset to glyph ClassDef table
2009 					 * containing lookahead sequence
2010 					 * data--from beginning of table */
2011   OffsetArrayOf<ChainRuleSet>
2012 		ruleSet;		/* Array of ChainRuleSet tables
2013 					 * ordered by class */
2014   public:
2015   DEFINE_SIZE_ARRAY (12, ruleSet);
2016 };
2017 
2018 struct ChainContextFormat3
2019 {
closureOT::ChainContextFormat32020   inline void closure (hb_closure_context_t *c) const
2021   {
2022     TRACE_CLOSURE (this);
2023     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2024 
2025     if (!(this+input[0]).intersects (c->glyphs))
2026       return;
2027 
2028     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2029     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2030     struct ChainContextClosureLookupContext lookup_context = {
2031       {intersects_coverage},
2032       {this, this, this}
2033     };
2034     chain_context_closure_lookup (c,
2035 				  backtrack.len, (const USHORT *) backtrack.array,
2036 				  input.len, (const USHORT *) input.array + 1,
2037 				  lookahead.len, (const USHORT *) lookahead.array,
2038 				  lookup.len, lookup.array,
2039 				  lookup_context);
2040   }
2041 
collect_glyphsOT::ChainContextFormat32042   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
2043   {
2044     TRACE_COLLECT_GLYPHS (this);
2045     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2046 
2047     (this+input[0]).add_coverage (c->input);
2048 
2049     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2050     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2051     struct ChainContextCollectGlyphsLookupContext lookup_context = {
2052       {collect_coverage},
2053       {this, this, this}
2054     };
2055     chain_context_collect_glyphs_lookup (c,
2056 					 backtrack.len, (const USHORT *) backtrack.array,
2057 					 input.len, (const USHORT *) input.array + 1,
2058 					 lookahead.len, (const USHORT *) lookahead.array,
2059 					 lookup.len, lookup.array,
2060 					 lookup_context);
2061   }
2062 
would_applyOT::ChainContextFormat32063   inline bool would_apply (hb_would_apply_context_t *c) const
2064   {
2065     TRACE_WOULD_APPLY (this);
2066 
2067     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2068     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2069     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2070     struct ChainContextApplyLookupContext lookup_context = {
2071       {match_coverage},
2072       {this, this, this}
2073     };
2074     return TRACE_RETURN (chain_context_would_apply_lookup (c,
2075 							   backtrack.len, (const USHORT *) backtrack.array,
2076 							   input.len, (const USHORT *) input.array + 1,
2077 							   lookahead.len, (const USHORT *) lookahead.array,
2078 							   lookup.len, lookup.array, lookup_context));
2079   }
2080 
get_coverageOT::ChainContextFormat32081   inline const Coverage &get_coverage (void) const
2082   {
2083     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2084     return this+input[0];
2085   }
2086 
applyOT::ChainContextFormat32087   inline bool apply (hb_apply_context_t *c) const
2088   {
2089     TRACE_APPLY (this);
2090     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2091 
2092     unsigned int index = (this+input[0]).get_coverage (c->buffer->cur().codepoint);
2093     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
2094 
2095     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2096     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2097     struct ChainContextApplyLookupContext lookup_context = {
2098       {match_coverage},
2099       {this, this, this}
2100     };
2101     return TRACE_RETURN (chain_context_apply_lookup (c,
2102 						     backtrack.len, (const USHORT *) backtrack.array,
2103 						     input.len, (const USHORT *) input.array + 1,
2104 						     lookahead.len, (const USHORT *) lookahead.array,
2105 						     lookup.len, lookup.array, lookup_context));
2106   }
2107 
sanitizeOT::ChainContextFormat32108   inline bool sanitize (hb_sanitize_context_t *c) {
2109     TRACE_SANITIZE (this);
2110     if (!backtrack.sanitize (c, this)) return TRACE_RETURN (false);
2111     OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2112     if (!input.sanitize (c, this)) return TRACE_RETURN (false);
2113     if (!input.len) return TRACE_RETURN (false); /* To be consistent with Context. */
2114     OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2115     if (!lookahead.sanitize (c, this)) return TRACE_RETURN (false);
2116     ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2117     return TRACE_RETURN (lookup.sanitize (c));
2118   }
2119 
2120   protected:
2121   USHORT	format;			/* Format identifier--format = 3 */
2122   OffsetArrayOf<Coverage>
2123 		backtrack;		/* Array of coverage tables
2124 					 * in backtracking sequence, in  glyph
2125 					 * sequence order */
2126   OffsetArrayOf<Coverage>
2127 		inputX		;	/* Array of coverage
2128 					 * tables in input sequence, in glyph
2129 					 * sequence order */
2130   OffsetArrayOf<Coverage>
2131 		lookaheadX;		/* Array of coverage tables
2132 					 * in lookahead sequence, in glyph
2133 					 * sequence order */
2134   ArrayOf<LookupRecord>
2135 		lookupX;		/* Array of LookupRecords--in
2136 					 * design order) */
2137   public:
2138   DEFINE_SIZE_MIN (10);
2139 };
2140 
2141 struct ChainContext
2142 {
2143   template <typename context_t>
dispatchOT::ChainContext2144   inline typename context_t::return_t dispatch (context_t *c) const
2145   {
2146     TRACE_DISPATCH (this, u.format);
2147     switch (u.format) {
2148     case 1: return TRACE_RETURN (c->dispatch (u.format1));
2149     case 2: return TRACE_RETURN (c->dispatch (u.format2));
2150     case 3: return TRACE_RETURN (c->dispatch (u.format3));
2151     default:return TRACE_RETURN (c->default_return_value ());
2152     }
2153   }
2154 
sanitizeOT::ChainContext2155   inline bool sanitize (hb_sanitize_context_t *c) {
2156     TRACE_SANITIZE (this);
2157     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
2158     switch (u.format) {
2159     case 1: return TRACE_RETURN (u.format1.sanitize (c));
2160     case 2: return TRACE_RETURN (u.format2.sanitize (c));
2161     case 3: return TRACE_RETURN (u.format3.sanitize (c));
2162     default:return TRACE_RETURN (true);
2163     }
2164   }
2165 
2166   protected:
2167   union {
2168   USHORT		format;	/* Format identifier */
2169   ChainContextFormat1	format1;
2170   ChainContextFormat2	format2;
2171   ChainContextFormat3	format3;
2172   } u;
2173 };
2174 
2175 
2176 struct ExtensionFormat1
2177 {
get_typeOT::ExtensionFormat12178   inline unsigned int get_type (void) const { return extensionLookupType; }
get_offsetOT::ExtensionFormat12179   inline unsigned int get_offset (void) const { return extensionOffset; }
2180 
sanitizeOT::ExtensionFormat12181   inline bool sanitize (hb_sanitize_context_t *c) {
2182     TRACE_SANITIZE (this);
2183     return TRACE_RETURN (c->check_struct (this));
2184   }
2185 
2186   protected:
2187   USHORT	format;			/* Format identifier. Set to 1. */
2188   USHORT	extensionLookupType;	/* Lookup type of subtable referenced
2189 					 * by ExtensionOffset (i.e. the
2190 					 * extension subtable). */
2191   ULONG		extensionOffset;	/* Offset to the extension subtable,
2192 					 * of lookup type subtable. */
2193   public:
2194   DEFINE_SIZE_STATIC (8);
2195 };
2196 
2197 template <typename T>
2198 struct Extension
2199 {
get_typeOT::Extension2200   inline unsigned int get_type (void) const
2201   {
2202     switch (u.format) {
2203     case 1: return u.format1.get_type ();
2204     default:return 0;
2205     }
2206   }
get_offsetOT::Extension2207   inline unsigned int get_offset (void) const
2208   {
2209     switch (u.format) {
2210     case 1: return u.format1.get_offset ();
2211     default:return 0;
2212     }
2213   }
2214 
2215   template <typename X>
get_subtableOT::Extension2216   inline const X& get_subtable (void) const
2217   {
2218     unsigned int offset = get_offset ();
2219     if (unlikely (!offset)) return Null(typename T::LookupSubTable);
2220     return StructAtOffset<typename T::LookupSubTable> (this, offset);
2221   }
2222 
2223   template <typename context_t>
dispatchOT::Extension2224   inline typename context_t::return_t dispatch (context_t *c) const
2225   {
2226     return get_subtable<typename T::LookupSubTable> ().dispatch (c, get_type ());
2227   }
2228 
sanitize_selfOT::Extension2229   inline bool sanitize_self (hb_sanitize_context_t *c) {
2230     TRACE_SANITIZE (this);
2231     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
2232     switch (u.format) {
2233     case 1: return TRACE_RETURN (u.format1.sanitize (c));
2234     default:return TRACE_RETURN (true);
2235     }
2236   }
2237 
sanitizeOT::Extension2238   inline bool sanitize (hb_sanitize_context_t *c) {
2239     TRACE_SANITIZE (this);
2240     if (!sanitize_self (c)) return TRACE_RETURN (false);
2241     unsigned int offset = get_offset ();
2242     if (unlikely (!offset)) return TRACE_RETURN (true);
2243     return TRACE_RETURN (StructAtOffset<typename T::LookupSubTable> (this, offset).sanitize (c, get_type ()));
2244   }
2245 
2246   protected:
2247   union {
2248   USHORT		format;		/* Format identifier */
2249   ExtensionFormat1	format1;
2250   } u;
2251 };
2252 
2253 
2254 /*
2255  * GSUB/GPOS Common
2256  */
2257 
2258 struct GSUBGPOS
2259 {
2260   static const hb_tag_t GSUBTag	= HB_OT_TAG_GSUB;
2261   static const hb_tag_t GPOSTag	= HB_OT_TAG_GPOS;
2262 
get_script_countOT::GSUBGPOS2263   inline unsigned int get_script_count (void) const
2264   { return (this+scriptList).len; }
get_script_tagOT::GSUBGPOS2265   inline const Tag& get_script_tag (unsigned int i) const
2266   { return (this+scriptList).get_tag (i); }
get_script_tagsOT::GSUBGPOS2267   inline unsigned int get_script_tags (unsigned int start_offset,
2268 				       unsigned int *script_count /* IN/OUT */,
2269 				       hb_tag_t     *script_tags /* OUT */) const
2270   { return (this+scriptList).get_tags (start_offset, script_count, script_tags); }
get_scriptOT::GSUBGPOS2271   inline const Script& get_script (unsigned int i) const
2272   { return (this+scriptList)[i]; }
find_script_indexOT::GSUBGPOS2273   inline bool find_script_index (hb_tag_t tag, unsigned int *index) const
2274   { return (this+scriptList).find_index (tag, index); }
2275 
get_feature_countOT::GSUBGPOS2276   inline unsigned int get_feature_count (void) const
2277   { return (this+featureList).len; }
get_feature_tagOT::GSUBGPOS2278   inline hb_tag_t get_feature_tag (unsigned int i) const
2279   { return i == Index::NOT_FOUND_INDEX ? HB_TAG_NONE : (this+featureList).get_tag (i); }
get_feature_tagsOT::GSUBGPOS2280   inline unsigned int get_feature_tags (unsigned int start_offset,
2281 					unsigned int *feature_count /* IN/OUT */,
2282 					hb_tag_t     *feature_tags /* OUT */) const
2283   { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); }
get_featureOT::GSUBGPOS2284   inline const Feature& get_feature (unsigned int i) const
2285   { return (this+featureList)[i]; }
find_feature_indexOT::GSUBGPOS2286   inline bool find_feature_index (hb_tag_t tag, unsigned int *index) const
2287   { return (this+featureList).find_index (tag, index); }
2288 
get_lookup_countOT::GSUBGPOS2289   inline unsigned int get_lookup_count (void) const
2290   { return (this+lookupList).len; }
get_lookupOT::GSUBGPOS2291   inline const Lookup& get_lookup (unsigned int i) const
2292   { return (this+lookupList)[i]; }
2293 
sanitizeOT::GSUBGPOS2294   inline bool sanitize (hb_sanitize_context_t *c) {
2295     TRACE_SANITIZE (this);
2296     return TRACE_RETURN (version.sanitize (c) && likely (version.major == 1) &&
2297 			 scriptList.sanitize (c, this) &&
2298 			 featureList.sanitize (c, this) &&
2299 			 lookupList.sanitize (c, this));
2300   }
2301 
2302   protected:
2303   FixedVersion	version;	/* Version of the GSUB/GPOS table--initially set
2304 				 * to 0x00010000u */
2305   OffsetTo<ScriptList>
2306 		scriptList;  	/* ScriptList table */
2307   OffsetTo<FeatureList>
2308 		featureList; 	/* FeatureList table */
2309   OffsetTo<LookupList>
2310 		lookupList; 	/* LookupList table */
2311   public:
2312   DEFINE_SIZE_STATIC (10);
2313 };
2314 
2315 
2316 } /* namespace OT */
2317 
2318 
2319 #endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */
2320