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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 #ifndef HB_DEBUG_CLOSURE
41 #define HB_DEBUG_CLOSURE (HB_DEBUG+0)
42 #endif
43 
44 #define TRACE_CLOSURE(this) \
45 	hb_auto_trace_t<HB_DEBUG_CLOSURE, hb_void_t> trace \
46 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
47 	 "");
48 
49 struct hb_closure_context_t :
50        hb_dispatch_context_t<hb_closure_context_t, hb_void_t, HB_DEBUG_CLOSURE>
51 {
get_nameOT::hb_closure_context_t52   inline const char *get_name (void) { return "CLOSURE"; }
53   typedef return_t (*recurse_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
54   template <typename T>
dispatchOT::hb_closure_context_t55   inline return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; }
default_return_valueOT::hb_closure_context_t56   static return_t default_return_value (void) { return HB_VOID; }
stop_sublookup_iterationOT::hb_closure_context_t57   bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
recurseOT::hb_closure_context_t58   return_t recurse (unsigned int lookup_index)
59   {
60     if (unlikely (nesting_level_left == 0 || !recurse_func))
61       return default_return_value ();
62 
63     nesting_level_left--;
64     recurse_func (this, lookup_index);
65     nesting_level_left++;
66     return HB_VOID;
67   }
68 
69   hb_face_t *face;
70   hb_set_t *glyphs;
71   recurse_func_t recurse_func;
72   unsigned int nesting_level_left;
73   unsigned int debug_depth;
74 
hb_closure_context_tOT::hb_closure_context_t75   hb_closure_context_t (hb_face_t *face_,
76 			hb_set_t *glyphs_,
77 		        unsigned int nesting_level_left_ = HB_MAX_NESTING_LEVEL) :
78 			  face (face_),
79 			  glyphs (glyphs_),
80 			  recurse_func (NULL),
81 			  nesting_level_left (nesting_level_left_),
82 			  debug_depth (0) {}
83 
set_recurse_funcOT::hb_closure_context_t84   void set_recurse_func (recurse_func_t func) { recurse_func = func; }
85 };
86 
87 
88 
89 #ifndef HB_DEBUG_WOULD_APPLY
90 #define HB_DEBUG_WOULD_APPLY (HB_DEBUG+0)
91 #endif
92 
93 #define TRACE_WOULD_APPLY(this) \
94 	hb_auto_trace_t<HB_DEBUG_WOULD_APPLY, bool> trace \
95 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
96 	 "%d glyphs", c->len);
97 
98 struct hb_would_apply_context_t :
99        hb_dispatch_context_t<hb_would_apply_context_t, bool, HB_DEBUG_WOULD_APPLY>
100 {
get_nameOT::hb_would_apply_context_t101   inline const char *get_name (void) { return "WOULD_APPLY"; }
102   template <typename T>
dispatchOT::hb_would_apply_context_t103   inline return_t dispatch (const T &obj) { return obj.would_apply (this); }
default_return_valueOT::hb_would_apply_context_t104   static return_t default_return_value (void) { return false; }
stop_sublookup_iterationOT::hb_would_apply_context_t105   bool stop_sublookup_iteration (return_t r) const { return r; }
106 
107   hb_face_t *face;
108   const hb_codepoint_t *glyphs;
109   unsigned int len;
110   bool zero_context;
111   unsigned int debug_depth;
112 
hb_would_apply_context_tOT::hb_would_apply_context_t113   hb_would_apply_context_t (hb_face_t *face_,
114 			    const hb_codepoint_t *glyphs_,
115 			    unsigned int len_,
116 			    bool zero_context_) :
117 			      face (face_),
118 			      glyphs (glyphs_),
119 			      len (len_),
120 			      zero_context (zero_context_),
121 			      debug_depth (0) {}
122 };
123 
124 
125 
126 #ifndef HB_DEBUG_COLLECT_GLYPHS
127 #define HB_DEBUG_COLLECT_GLYPHS (HB_DEBUG+0)
128 #endif
129 
130 #define TRACE_COLLECT_GLYPHS(this) \
131 	hb_auto_trace_t<HB_DEBUG_COLLECT_GLYPHS, hb_void_t> trace \
132 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
133 	 "");
134 
135 struct hb_collect_glyphs_context_t :
136        hb_dispatch_context_t<hb_collect_glyphs_context_t, hb_void_t, HB_DEBUG_COLLECT_GLYPHS>
137 {
get_nameOT::hb_collect_glyphs_context_t138   inline const char *get_name (void) { return "COLLECT_GLYPHS"; }
139   typedef return_t (*recurse_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
140   template <typename T>
dispatchOT::hb_collect_glyphs_context_t141   inline return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
default_return_valueOT::hb_collect_glyphs_context_t142   static return_t default_return_value (void) { return HB_VOID; }
stop_sublookup_iterationOT::hb_collect_glyphs_context_t143   bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
recurseOT::hb_collect_glyphs_context_t144   return_t recurse (unsigned int lookup_index)
145   {
146     if (unlikely (nesting_level_left == 0 || !recurse_func))
147       return default_return_value ();
148 
149     /* Note that GPOS sets recurse_func to NULL already, so it doesn't get
150      * past the previous check.  For GSUB, we only want to collect the output
151      * glyphs in the recursion.  If output is not requested, we can go home now.
152      *
153      * Note further, that the above is not exactly correct.  A recursed lookup
154      * is allowed to match input that is not matched in the context, but that's
155      * not how most fonts are built.  It's possible to relax that and recurse
156      * with all sets here if it proves to be an issue.
157      */
158 
159     if (output == hb_set_get_empty ())
160       return HB_VOID;
161 
162     /* Return if new lookup was recursed to before. */
163     if (recursed_lookups.has (lookup_index))
164       return HB_VOID;
165 
166     hb_set_t *old_before = before;
167     hb_set_t *old_input  = input;
168     hb_set_t *old_after  = after;
169     before = input = after = hb_set_get_empty ();
170 
171     nesting_level_left--;
172     recurse_func (this, lookup_index);
173     nesting_level_left++;
174 
175     before = old_before;
176     input  = old_input;
177     after  = old_after;
178 
179     recursed_lookups.add (lookup_index);
180 
181     return HB_VOID;
182   }
183 
184   hb_face_t *face;
185   hb_set_t *before;
186   hb_set_t *input;
187   hb_set_t *after;
188   hb_set_t *output;
189   recurse_func_t recurse_func;
190   hb_set_t recursed_lookups;
191   unsigned int nesting_level_left;
192   unsigned int debug_depth;
193 
hb_collect_glyphs_context_tOT::hb_collect_glyphs_context_t194   hb_collect_glyphs_context_t (hb_face_t *face_,
195 			       hb_set_t  *glyphs_before, /* OUT. May be NULL */
196 			       hb_set_t  *glyphs_input,  /* OUT. May be NULL */
197 			       hb_set_t  *glyphs_after,  /* OUT. May be NULL */
198 			       hb_set_t  *glyphs_output, /* OUT. May be NULL */
199 			       unsigned int nesting_level_left_ = HB_MAX_NESTING_LEVEL) :
200 			      face (face_),
201 			      before (glyphs_before ? glyphs_before : hb_set_get_empty ()),
202 			      input  (glyphs_input  ? glyphs_input  : hb_set_get_empty ()),
203 			      after  (glyphs_after  ? glyphs_after  : hb_set_get_empty ()),
204 			      output (glyphs_output ? glyphs_output : hb_set_get_empty ()),
205 			      recurse_func (NULL),
206 			      recursed_lookups (),
207 			      nesting_level_left (nesting_level_left_),
208 			      debug_depth (0)
209   {
210     recursed_lookups.init ();
211   }
~hb_collect_glyphs_context_tOT::hb_collect_glyphs_context_t212   ~hb_collect_glyphs_context_t (void)
213   {
214     recursed_lookups.fini ();
215   }
216 
set_recurse_funcOT::hb_collect_glyphs_context_t217   void set_recurse_func (recurse_func_t func) { recurse_func = func; }
218 };
219 
220 
221 
222 #ifndef HB_DEBUG_GET_COVERAGE
223 #define HB_DEBUG_GET_COVERAGE (HB_DEBUG+0)
224 #endif
225 
226 /* XXX Can we remove this? */
227 
228 template <typename set_t>
229 struct hb_add_coverage_context_t :
230        hb_dispatch_context_t<hb_add_coverage_context_t<set_t>, const Coverage &, HB_DEBUG_GET_COVERAGE>
231 {
get_nameOT::hb_add_coverage_context_t232   inline const char *get_name (void) { return "GET_COVERAGE"; }
233   typedef const Coverage &return_t;
234   template <typename T>
dispatchOT::hb_add_coverage_context_t235   inline return_t dispatch (const T &obj) { return obj.get_coverage (); }
default_return_valueOT::hb_add_coverage_context_t236   static return_t default_return_value (void) { return Null(Coverage); }
stop_sublookup_iterationOT::hb_add_coverage_context_t237   bool stop_sublookup_iteration (return_t r) const
238   {
239     r.add_coverage (set);
240     return false;
241   }
242 
hb_add_coverage_context_tOT::hb_add_coverage_context_t243   hb_add_coverage_context_t (set_t *set_) :
244 			    set (set_),
245 			    debug_depth (0) {}
246 
247   set_t *set;
248   unsigned int debug_depth;
249 };
250 
251 
252 
253 #ifndef HB_DEBUG_APPLY
254 #define HB_DEBUG_APPLY (HB_DEBUG+0)
255 #endif
256 
257 #define TRACE_APPLY(this) \
258 	hb_auto_trace_t<HB_DEBUG_APPLY, bool> trace \
259 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
260 	 "idx %d gid %u lookup %d", \
261 	 c->buffer->idx, c->buffer->cur().codepoint, (int) c->lookup_index);
262 
263 struct hb_apply_context_t :
264        hb_dispatch_context_t<hb_apply_context_t, bool, HB_DEBUG_APPLY>
265 {
266   struct matcher_t
267   {
matcher_tOT::hb_apply_context_t::matcher_t268     inline matcher_t (void) :
269 	     lookup_props (0),
270 	     ignore_zwnj (false),
271 	     ignore_zwj (false),
272 	     mask (-1),
273 #define arg1(arg) (arg) /* Remove the macro to see why it's needed! */
274 	     syllable arg1(0),
275 #undef arg1
276 	     match_func (NULL),
277 	     match_data (NULL) {};
278 
279     typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
280 
set_ignore_zwnjOT::hb_apply_context_t::matcher_t281     inline void set_ignore_zwnj (bool ignore_zwnj_) { ignore_zwnj = ignore_zwnj_; }
set_ignore_zwjOT::hb_apply_context_t::matcher_t282     inline void set_ignore_zwj (bool ignore_zwj_) { ignore_zwj = ignore_zwj_; }
set_lookup_propsOT::hb_apply_context_t::matcher_t283     inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
set_maskOT::hb_apply_context_t::matcher_t284     inline void set_mask (hb_mask_t mask_) { mask = mask_; }
set_syllableOT::hb_apply_context_t::matcher_t285     inline void set_syllable (uint8_t syllable_)  { syllable = syllable_; }
set_match_funcOT::hb_apply_context_t::matcher_t286     inline void set_match_func (match_func_t match_func_,
287 				const void *match_data_)
288     { match_func = match_func_; match_data = match_data_; }
289 
290     enum may_match_t {
291       MATCH_NO,
292       MATCH_YES,
293       MATCH_MAYBE
294     };
295 
may_matchOT::hb_apply_context_t::matcher_t296     inline may_match_t may_match (const hb_glyph_info_t &info,
297 				  const USHORT          *glyph_data) const
298     {
299       if (!(info.mask & mask) ||
300 	  (syllable && syllable != info.syllable ()))
301 	return MATCH_NO;
302 
303       if (match_func)
304         return match_func (info.codepoint, *glyph_data, match_data) ? MATCH_YES : MATCH_NO;
305 
306       return MATCH_MAYBE;
307     }
308 
309     enum may_skip_t {
310       SKIP_NO,
311       SKIP_YES,
312       SKIP_MAYBE
313     };
314 
315     inline may_skip_t
may_skipOT::hb_apply_context_t::matcher_t316     may_skip (const hb_apply_context_t *c,
317 	      const hb_glyph_info_t    &info) const
318     {
319       if (!c->check_glyph_property (&info, lookup_props))
320 	return SKIP_YES;
321 
322       if (unlikely (_hb_glyph_info_is_default_ignorable (&info) &&
323 		    (ignore_zwnj || !_hb_glyph_info_is_zwnj (&info)) &&
324 		    (ignore_zwj || !_hb_glyph_info_is_zwj (&info))))
325 	return SKIP_MAYBE;
326 
327       return SKIP_NO;
328     }
329 
330     protected:
331     unsigned int lookup_props;
332     bool ignore_zwnj;
333     bool ignore_zwj;
334     hb_mask_t mask;
335     uint8_t syllable;
336     match_func_t match_func;
337     const void *match_data;
338   };
339 
340   struct skipping_iterator_t
341   {
initOT::hb_apply_context_t::skipping_iterator_t342     inline void init (hb_apply_context_t *c_, bool context_match = false)
343     {
344       c = c_;
345       match_glyph_data = NULL,
346       matcher.set_match_func (NULL, NULL);
347       matcher.set_lookup_props (c->lookup_props);
348       /* Ignore ZWNJ if we are matching GSUB context, or matching GPOS. */
349       matcher.set_ignore_zwnj (context_match || c->table_index == 1);
350       /* Ignore ZWJ if we are matching GSUB context, or matching GPOS, or if asked to. */
351       matcher.set_ignore_zwj (context_match || c->table_index == 1 || c->auto_zwj);
352       matcher.set_mask (context_match ? -1 : c->lookup_mask);
353     }
set_lookup_propsOT::hb_apply_context_t::skipping_iterator_t354     inline void set_lookup_props (unsigned int lookup_props)
355     {
356       matcher.set_lookup_props (lookup_props);
357     }
set_match_funcOT::hb_apply_context_t::skipping_iterator_t358     inline void set_match_func (matcher_t::match_func_t match_func_,
359 				const void *match_data_,
360 				const USHORT glyph_data[])
361     {
362       matcher.set_match_func (match_func_, match_data_);
363       match_glyph_data = glyph_data;
364     }
365 
resetOT::hb_apply_context_t::skipping_iterator_t366     inline void reset (unsigned int start_index_,
367 		       unsigned int num_items_)
368     {
369       idx = start_index_;
370       num_items = num_items_;
371       end = c->buffer->len;
372       matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
373     }
374 
rejectOT::hb_apply_context_t::skipping_iterator_t375     inline void reject (void) { num_items++; match_glyph_data--; }
376 
nextOT::hb_apply_context_t::skipping_iterator_t377     inline bool next (void)
378     {
379       assert (num_items > 0);
380       while (idx + num_items < end)
381       {
382 	idx++;
383 	const hb_glyph_info_t &info = c->buffer->info[idx];
384 
385 	matcher_t::may_skip_t skip = matcher.may_skip (c, info);
386 	if (unlikely (skip == matcher_t::SKIP_YES))
387 	  continue;
388 
389 	matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
390 	if (match == matcher_t::MATCH_YES ||
391 	    (match == matcher_t::MATCH_MAYBE &&
392 	     skip == matcher_t::SKIP_NO))
393 	{
394 	  num_items--;
395 	  match_glyph_data++;
396 	  return true;
397 	}
398 
399 	if (skip == matcher_t::SKIP_NO)
400 	  return false;
401       }
402       return false;
403     }
prevOT::hb_apply_context_t::skipping_iterator_t404     inline bool prev (void)
405     {
406       assert (num_items > 0);
407       while (idx >= num_items)
408       {
409 	idx--;
410 	const hb_glyph_info_t &info = c->buffer->out_info[idx];
411 
412 	matcher_t::may_skip_t skip = matcher.may_skip (c, info);
413 	if (unlikely (skip == matcher_t::SKIP_YES))
414 	  continue;
415 
416 	matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
417 	if (match == matcher_t::MATCH_YES ||
418 	    (match == matcher_t::MATCH_MAYBE &&
419 	     skip == matcher_t::SKIP_NO))
420 	{
421 	  num_items--;
422 	  match_glyph_data++;
423 	  return true;
424 	}
425 
426 	if (skip == matcher_t::SKIP_NO)
427 	  return false;
428       }
429       return false;
430     }
431 
432     unsigned int idx;
433     protected:
434     hb_apply_context_t *c;
435     matcher_t matcher;
436     const USHORT *match_glyph_data;
437 
438     unsigned int num_items;
439     unsigned int end;
440   };
441 
442 
get_nameOT::hb_apply_context_t443   inline const char *get_name (void) { return "APPLY"; }
444   typedef return_t (*recurse_func_t) (hb_apply_context_t *c, unsigned int lookup_index);
445   template <typename T>
dispatchOT::hb_apply_context_t446   inline return_t dispatch (const T &obj) { return obj.apply (this); }
default_return_valueOT::hb_apply_context_t447   static return_t default_return_value (void) { return false; }
stop_sublookup_iterationOT::hb_apply_context_t448   bool stop_sublookup_iteration (return_t r) const { return r; }
recurseOT::hb_apply_context_t449   return_t recurse (unsigned int lookup_index)
450   {
451     if (unlikely (nesting_level_left == 0 || !recurse_func))
452       return default_return_value ();
453 
454     nesting_level_left--;
455     bool ret = recurse_func (this, lookup_index);
456     nesting_level_left++;
457     return ret;
458   }
459 
460   unsigned int table_index; /* GSUB/GPOS */
461   hb_font_t *font;
462   hb_face_t *face;
463   hb_buffer_t *buffer;
464   hb_direction_t direction;
465   hb_mask_t lookup_mask;
466   bool auto_zwj;
467   recurse_func_t recurse_func;
468   unsigned int nesting_level_left;
469   unsigned int lookup_props;
470   const GDEF &gdef;
471   bool has_glyph_classes;
472   skipping_iterator_t iter_input, iter_context;
473   unsigned int lookup_index;
474   unsigned int debug_depth;
475 
476 
hb_apply_context_tOT::hb_apply_context_t477   hb_apply_context_t (unsigned int table_index_,
478 		      hb_font_t *font_,
479 		      hb_buffer_t *buffer_) :
480 			table_index (table_index_),
481 			font (font_), face (font->face), buffer (buffer_),
482 			direction (buffer_->props.direction),
483 			lookup_mask (1),
484 			auto_zwj (true),
485 			recurse_func (NULL),
486 			nesting_level_left (HB_MAX_NESTING_LEVEL),
487 			lookup_props (0),
488 			gdef (*hb_ot_layout_from_face (face)->gdef),
489 			has_glyph_classes (gdef.has_glyph_classes ()),
490 			iter_input (),
491 			iter_context (),
492 			lookup_index ((unsigned int) -1),
493 			debug_depth (0) {}
494 
set_lookup_maskOT::hb_apply_context_t495   inline void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; }
set_auto_zwjOT::hb_apply_context_t496   inline void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; }
set_recurse_funcOT::hb_apply_context_t497   inline void set_recurse_func (recurse_func_t func) { recurse_func = func; }
set_lookup_indexOT::hb_apply_context_t498   inline void set_lookup_index (unsigned int lookup_index_) { lookup_index = lookup_index_; }
set_lookup_propsOT::hb_apply_context_t499   inline void set_lookup_props (unsigned int lookup_props_)
500   {
501     lookup_props = lookup_props_;
502     iter_input.init (this, false);
503     iter_context.init (this, true);
504   }
505 
506   inline bool
match_properties_markOT::hb_apply_context_t507   match_properties_mark (hb_codepoint_t  glyph,
508 			 unsigned int    glyph_props,
509 			 unsigned int    match_props) const
510   {
511     /* If using mark filtering sets, the high short of
512      * match_props has the set index.
513      */
514     if (match_props & LookupFlag::UseMarkFilteringSet)
515       return gdef.mark_set_covers (match_props >> 16, glyph);
516 
517     /* The second byte of match_props has the meaning
518      * "ignore marks of attachment type different than
519      * the attachment type specified."
520      */
521     if (match_props & LookupFlag::MarkAttachmentType)
522       return (match_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType);
523 
524     return true;
525   }
526 
527   inline bool
check_glyph_propertyOT::hb_apply_context_t528   check_glyph_property (const hb_glyph_info_t *info,
529 			unsigned int  match_props) const
530   {
531     hb_codepoint_t glyph = info->codepoint;
532     unsigned int glyph_props = _hb_glyph_info_get_glyph_props (info);
533 
534     /* Not covered, if, for example, glyph class is ligature and
535      * match_props includes LookupFlags::IgnoreLigatures
536      */
537     if (glyph_props & match_props & LookupFlag::IgnoreFlags)
538       return false;
539 
540     if (unlikely (glyph_props & HB_OT_LAYOUT_GLYPH_PROPS_MARK))
541       return match_properties_mark (glyph, glyph_props, match_props);
542 
543     return true;
544   }
545 
_set_glyph_propsOT::hb_apply_context_t546   inline void _set_glyph_props (hb_codepoint_t glyph_index,
547 			  unsigned int class_guess = 0,
548 			  bool ligature = false,
549 			  bool component = false) const
550   {
551     unsigned int add_in = _hb_glyph_info_get_glyph_props (&buffer->cur()) &
552 			  HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE;
553     add_in |= HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED;
554     if (ligature)
555     {
556       add_in |= HB_OT_LAYOUT_GLYPH_PROPS_LIGATED;
557       /* In the only place that the MULTIPLIED bit is used, Uniscribe
558        * seems to only care about the "last" transformation between
559        * Ligature and Multiple substitions.  Ie. if you ligate, expand,
560        * and ligate again, it forgives the multiplication and acts as
561        * if only ligation happened.  As such, clear MULTIPLIED bit.
562        */
563       add_in &= ~HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
564     }
565     if (component)
566       add_in |= HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
567     if (likely (has_glyph_classes))
568       _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | gdef.get_glyph_props (glyph_index));
569     else if (class_guess)
570       _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | class_guess);
571   }
572 
replace_glyphOT::hb_apply_context_t573   inline void replace_glyph (hb_codepoint_t glyph_index) const
574   {
575     _set_glyph_props (glyph_index);
576     buffer->replace_glyph (glyph_index);
577   }
replace_glyph_inplaceOT::hb_apply_context_t578   inline void replace_glyph_inplace (hb_codepoint_t glyph_index) const
579   {
580     _set_glyph_props (glyph_index);
581     buffer->cur().codepoint = glyph_index;
582   }
replace_glyph_with_ligatureOT::hb_apply_context_t583   inline void replace_glyph_with_ligature (hb_codepoint_t glyph_index,
584 					   unsigned int class_guess) const
585   {
586     _set_glyph_props (glyph_index, class_guess, true);
587     buffer->replace_glyph (glyph_index);
588   }
output_glyph_for_componentOT::hb_apply_context_t589   inline void output_glyph_for_component (hb_codepoint_t glyph_index,
590 					  unsigned int class_guess) const
591   {
592     _set_glyph_props (glyph_index, class_guess, false, true);
593     buffer->output_glyph (glyph_index);
594   }
595 };
596 
597 
598 
599 typedef bool (*intersects_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
600 typedef void (*collect_glyphs_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
601 typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
602 
603 struct ContextClosureFuncs
604 {
605   intersects_func_t intersects;
606 };
607 struct ContextCollectGlyphsFuncs
608 {
609   collect_glyphs_func_t collect;
610 };
611 struct ContextApplyFuncs
612 {
613   match_func_t match;
614 };
615 
616 
intersects_glyph(hb_set_t * glyphs,const USHORT & value,const void * data HB_UNUSED)617 static inline bool intersects_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
618 {
619   return glyphs->has (value);
620 }
intersects_class(hb_set_t * glyphs,const USHORT & value,const void * data)621 static inline bool intersects_class (hb_set_t *glyphs, const USHORT &value, const void *data)
622 {
623   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
624   return class_def.intersects_class (glyphs, value);
625 }
intersects_coverage(hb_set_t * glyphs,const USHORT & value,const void * data)626 static inline bool intersects_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
627 {
628   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
629   return (data+coverage).intersects (glyphs);
630 }
631 
intersects_array(hb_closure_context_t * c,unsigned int count,const USHORT values[],intersects_func_t intersects_func,const void * intersects_data)632 static inline bool intersects_array (hb_closure_context_t *c,
633 				     unsigned int count,
634 				     const USHORT values[],
635 				     intersects_func_t intersects_func,
636 				     const void *intersects_data)
637 {
638   for (unsigned int i = 0; i < count; i++)
639     if (likely (!intersects_func (c->glyphs, values[i], intersects_data)))
640       return false;
641   return true;
642 }
643 
644 
collect_glyph(hb_set_t * glyphs,const USHORT & value,const void * data HB_UNUSED)645 static inline void collect_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
646 {
647   glyphs->add (value);
648 }
collect_class(hb_set_t * glyphs,const USHORT & value,const void * data)649 static inline void collect_class (hb_set_t *glyphs, const USHORT &value, const void *data)
650 {
651   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
652   class_def.add_class (glyphs, value);
653 }
collect_coverage(hb_set_t * glyphs,const USHORT & value,const void * data)654 static inline void collect_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
655 {
656   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
657   (data+coverage).add_coverage (glyphs);
658 }
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)659 static inline void collect_array (hb_collect_glyphs_context_t *c HB_UNUSED,
660 				  hb_set_t *glyphs,
661 				  unsigned int count,
662 				  const USHORT values[],
663 				  collect_glyphs_func_t collect_func,
664 				  const void *collect_data)
665 {
666   for (unsigned int i = 0; i < count; i++)
667     collect_func (glyphs, values[i], collect_data);
668 }
669 
670 
match_glyph(hb_codepoint_t glyph_id,const USHORT & value,const void * data HB_UNUSED)671 static inline bool match_glyph (hb_codepoint_t glyph_id, const USHORT &value, const void *data HB_UNUSED)
672 {
673   return glyph_id == value;
674 }
match_class(hb_codepoint_t glyph_id,const USHORT & value,const void * data)675 static inline bool match_class (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
676 {
677   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
678   return class_def.get_class (glyph_id) == value;
679 }
match_coverage(hb_codepoint_t glyph_id,const USHORT & value,const void * data)680 static inline bool match_coverage (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
681 {
682   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
683   return (data+coverage).get_coverage (glyph_id) != NOT_COVERED;
684 }
685 
would_match_input(hb_would_apply_context_t * c,unsigned int count,const USHORT input[],match_func_t match_func,const void * match_data)686 static inline bool would_match_input (hb_would_apply_context_t *c,
687 				      unsigned int count, /* Including the first glyph (not matched) */
688 				      const USHORT input[], /* Array of input values--start with second glyph */
689 				      match_func_t match_func,
690 				      const void *match_data)
691 {
692   if (count != c->len)
693     return false;
694 
695   for (unsigned int i = 1; i < count; i++)
696     if (likely (!match_func (c->glyphs[i], input[i - 1], match_data)))
697       return false;
698 
699   return true;
700 }
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[HB_MAX_CONTEXT_LENGTH],bool * p_is_mark_ligature=NULL,unsigned int * p_total_component_count=NULL)701 static inline bool match_input (hb_apply_context_t *c,
702 				unsigned int count, /* Including the first glyph (not matched) */
703 				const USHORT input[], /* Array of input values--start with second glyph */
704 				match_func_t match_func,
705 				const void *match_data,
706 				unsigned int *end_offset,
707 				unsigned int match_positions[HB_MAX_CONTEXT_LENGTH],
708 				bool *p_is_mark_ligature = NULL,
709 				unsigned int *p_total_component_count = NULL)
710 {
711   TRACE_APPLY (NULL);
712 
713   if (unlikely (count > HB_MAX_CONTEXT_LENGTH)) return_trace (false);
714 
715   hb_buffer_t *buffer = c->buffer;
716 
717   hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
718   skippy_iter.reset (buffer->idx, count - 1);
719   skippy_iter.set_match_func (match_func, match_data, input);
720 
721   /*
722    * This is perhaps the trickiest part of OpenType...  Remarks:
723    *
724    * - If all components of the ligature were marks, we call this a mark ligature.
725    *
726    * - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize
727    *   it as a ligature glyph.
728    *
729    * - Ligatures cannot be formed across glyphs attached to different components
730    *   of previous ligatures.  Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and
731    *   LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother.
732    *   However, it would be wrong to ligate that SHADDA,FATHA sequence.o
733    *   There is an exception to this: If a ligature tries ligating with marks that
734    *   belong to it itself, go ahead, assuming that the font designer knows what
735    *   they are doing (otherwise it can break Indic stuff when a matra wants to
736    *   ligate with a conjunct...)
737    */
738 
739   bool is_mark_ligature = _hb_glyph_info_is_mark (&buffer->cur());
740 
741   unsigned int total_component_count = 0;
742   total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->cur());
743 
744   unsigned int first_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
745   unsigned int first_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
746 
747   match_positions[0] = buffer->idx;
748   for (unsigned int i = 1; i < count; i++)
749   {
750     if (!skippy_iter.next ()) return_trace (false);
751 
752     match_positions[i] = skippy_iter.idx;
753 
754     unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx]);
755     unsigned int this_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]);
756 
757     if (first_lig_id && first_lig_comp) {
758       /* If first component was attached to a previous ligature component,
759        * all subsequent components should be attached to the same ligature
760        * component, otherwise we shouldn't ligate them. */
761       if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp)
762 	return_trace (false);
763     } else {
764       /* If first component was NOT attached to a previous ligature component,
765        * all subsequent components should also NOT be attached to any ligature
766        * component, unless they are attached to the first component itself! */
767       if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id))
768 	return_trace (false);
769     }
770 
771     is_mark_ligature = is_mark_ligature && _hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx]);
772     total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->info[skippy_iter.idx]);
773   }
774 
775   *end_offset = skippy_iter.idx - buffer->idx + 1;
776 
777   if (p_is_mark_ligature)
778     *p_is_mark_ligature = is_mark_ligature;
779 
780   if (p_total_component_count)
781     *p_total_component_count = total_component_count;
782 
783   return_trace (true);
784 }
ligate_input(hb_apply_context_t * c,unsigned int count,unsigned int match_positions[HB_MAX_CONTEXT_LENGTH],unsigned int match_length,hb_codepoint_t lig_glyph,bool is_mark_ligature,unsigned int total_component_count)785 static inline bool ligate_input (hb_apply_context_t *c,
786 				 unsigned int count, /* Including the first glyph */
787 				 unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */
788 				 unsigned int match_length,
789 				 hb_codepoint_t lig_glyph,
790 				 bool is_mark_ligature,
791 				 unsigned int total_component_count)
792 {
793   TRACE_APPLY (NULL);
794 
795   hb_buffer_t *buffer = c->buffer;
796 
797   buffer->merge_clusters (buffer->idx, buffer->idx + match_length);
798 
799   /*
800    * - If it *is* a mark ligature, we don't allocate a new ligature id, and leave
801    *   the ligature to keep its old ligature id.  This will allow it to attach to
802    *   a base ligature in GPOS.  Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH,
803    *   and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA wit a
804    *   ligature id and component value of 2.  Then if SHADDA,FATHA form a ligature
805    *   later, we don't want them to lose their ligature id/component, otherwise
806    *   GPOS will fail to correctly position the mark ligature on top of the
807    *   LAM,LAM,HEH ligature.  See:
808    *     https://bugzilla.gnome.org/show_bug.cgi?id=676343
809    *
810    * - If a ligature is formed of components that some of which are also ligatures
811    *   themselves, and those ligature components had marks attached to *their*
812    *   components, we have to attach the marks to the new ligature component
813    *   positions!  Now *that*'s tricky!  And these marks may be following the
814    *   last component of the whole sequence, so we should loop forward looking
815    *   for them and update them.
816    *
817    *   Eg. the sequence is LAM,LAM,SHADDA,FATHA,HEH, and the font first forms a
818    *   'calt' ligature of LAM,HEH, leaving the SHADDA and FATHA with a ligature
819    *   id and component == 1.  Now, during 'liga', the LAM and the LAM-HEH ligature
820    *   form a LAM-LAM-HEH ligature.  We need to reassign the SHADDA and FATHA to
821    *   the new ligature with a component value of 2.
822    *
823    *   This in fact happened to a font...  See:
824    *   https://bugzilla.gnome.org/show_bug.cgi?id=437633
825    */
826 
827   unsigned int klass = is_mark_ligature ? 0 : HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE;
828   unsigned int lig_id = is_mark_ligature ? 0 : _hb_allocate_lig_id (buffer);
829   unsigned int last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
830   unsigned int last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
831   unsigned int components_so_far = last_num_components;
832 
833   if (!is_mark_ligature)
834   {
835     _hb_glyph_info_set_lig_props_for_ligature (&buffer->cur(), lig_id, total_component_count);
836     if (_hb_glyph_info_get_general_category (&buffer->cur()) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
837     {
838       _hb_glyph_info_set_general_category (&buffer->cur(), HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER);
839     }
840   }
841   c->replace_glyph_with_ligature (lig_glyph, klass);
842 
843   for (unsigned int i = 1; i < count; i++)
844   {
845     while (buffer->idx < match_positions[i] && !buffer->in_error)
846     {
847       if (!is_mark_ligature) {
848         unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
849 	if (this_comp == 0)
850 	  this_comp = last_num_components;
851 	unsigned int new_lig_comp = components_so_far - last_num_components +
852 				    MIN (this_comp, last_num_components);
853 	  _hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp);
854       }
855       buffer->next_glyph ();
856     }
857 
858     last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
859     last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
860     components_so_far += last_num_components;
861 
862     /* Skip the base glyph */
863     buffer->idx++;
864   }
865 
866   if (!is_mark_ligature && last_lig_id) {
867     /* Re-adjust components for any marks following. */
868     for (unsigned int i = buffer->idx; i < buffer->len; i++) {
869       if (last_lig_id == _hb_glyph_info_get_lig_id (&buffer->info[i])) {
870         unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->info[i]);
871 	if (!this_comp)
872 	  break;
873 	unsigned int new_lig_comp = components_so_far - last_num_components +
874 				    MIN (this_comp, last_num_components);
875 	_hb_glyph_info_set_lig_props_for_mark (&buffer->info[i], lig_id, new_lig_comp);
876       } else
877 	break;
878     }
879   }
880   return_trace (true);
881 }
882 
match_backtrack(hb_apply_context_t * c,unsigned int count,const USHORT backtrack[],match_func_t match_func,const void * match_data)883 static inline bool match_backtrack (hb_apply_context_t *c,
884 				    unsigned int count,
885 				    const USHORT backtrack[],
886 				    match_func_t match_func,
887 				    const void *match_data)
888 {
889   TRACE_APPLY (NULL);
890 
891   hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
892   skippy_iter.reset (c->buffer->backtrack_len (), count);
893   skippy_iter.set_match_func (match_func, match_data, backtrack);
894 
895   for (unsigned int i = 0; i < count; i++)
896     if (!skippy_iter.prev ())
897       return_trace (false);
898 
899   return_trace (true);
900 }
901 
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)902 static inline bool match_lookahead (hb_apply_context_t *c,
903 				    unsigned int count,
904 				    const USHORT lookahead[],
905 				    match_func_t match_func,
906 				    const void *match_data,
907 				    unsigned int offset)
908 {
909   TRACE_APPLY (NULL);
910 
911   hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
912   skippy_iter.reset (c->buffer->idx + offset - 1, count);
913   skippy_iter.set_match_func (match_func, match_data, lookahead);
914 
915   for (unsigned int i = 0; i < count; i++)
916     if (!skippy_iter.next ())
917       return_trace (false);
918 
919   return_trace (true);
920 }
921 
922 
923 
924 struct LookupRecord
925 {
sanitizeOT::LookupRecord926   inline bool sanitize (hb_sanitize_context_t *c) const
927   {
928     TRACE_SANITIZE (this);
929     return_trace (c->check_struct (this));
930   }
931 
932   USHORT	sequenceIndex;		/* Index into current glyph
933 					 * sequence--first glyph = 0 */
934   USHORT	lookupListIndex;	/* Lookup to apply to that
935 					 * position--zero--based */
936   public:
937   DEFINE_SIZE_STATIC (4);
938 };
939 
940 
941 template <typename context_t>
recurse_lookups(context_t * c,unsigned int lookupCount,const LookupRecord lookupRecord[])942 static inline void recurse_lookups (context_t *c,
943 				    unsigned int lookupCount,
944 				    const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
945 {
946   for (unsigned int i = 0; i < lookupCount; i++)
947     c->recurse (lookupRecord[i].lookupListIndex);
948 }
949 
apply_lookup(hb_apply_context_t * c,unsigned int count,unsigned int match_positions[HB_MAX_CONTEXT_LENGTH],unsigned int lookupCount,const LookupRecord lookupRecord[],unsigned int match_length)950 static inline bool apply_lookup (hb_apply_context_t *c,
951 				 unsigned int count, /* Including the first glyph */
952 				 unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */
953 				 unsigned int lookupCount,
954 				 const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */
955 				 unsigned int match_length)
956 {
957   TRACE_APPLY (NULL);
958 
959   hb_buffer_t *buffer = c->buffer;
960   unsigned int end;
961 
962   /* All positions are distance from beginning of *output* buffer.
963    * Adjust. */
964   {
965     unsigned int bl = buffer->backtrack_len ();
966     end = bl + match_length;
967 
968     int delta = bl - buffer->idx;
969     /* Convert positions to new indexing. */
970     for (unsigned int j = 0; j < count; j++)
971       match_positions[j] += delta;
972   }
973 
974   for (unsigned int i = 0; i < lookupCount && !buffer->in_error; i++)
975   {
976     unsigned int idx = lookupRecord[i].sequenceIndex;
977     if (idx >= count)
978       continue;
979 
980     /* Don't recurse to ourself at same position.
981      * Note that this test is too naive, it doesn't catch longer loops. */
982     if (idx == 0 && lookupRecord[i].lookupListIndex == c->lookup_index)
983       continue;
984 
985     buffer->move_to (match_positions[idx]);
986 
987     unsigned int orig_len = buffer->backtrack_len () + buffer->lookahead_len ();
988     if (!c->recurse (lookupRecord[i].lookupListIndex))
989       continue;
990 
991     unsigned int new_len = buffer->backtrack_len () + buffer->lookahead_len ();
992     int delta = new_len - orig_len;
993 
994     if (!delta)
995         continue;
996 
997     /* Recursed lookup changed buffer len.  Adjust. */
998 
999     /* end can't go back past the current match position.
1000      * Note: this is only true because we do NOT allow MultipleSubst
1001      * with zero sequence len. */
1002     end = MAX (MIN((int) match_positions[idx] + 1, (int) new_len), int (end) + delta);
1003 
1004     unsigned int next = idx + 1; /* next now is the position after the recursed lookup. */
1005 
1006     if (delta > 0)
1007     {
1008       if (unlikely (delta + count > HB_MAX_CONTEXT_LENGTH))
1009 	break;
1010     }
1011     else
1012     {
1013       /* NOTE: delta is negative. */
1014       delta = MAX (delta, (int) next - (int) count);
1015       next -= delta;
1016     }
1017 
1018     /* Shift! */
1019     memmove (match_positions + next + delta, match_positions + next,
1020 	     (count - next) * sizeof (match_positions[0]));
1021     next += delta;
1022     count += delta;
1023 
1024     /* Fill in new entries. */
1025     for (unsigned int j = idx + 1; j < next; j++)
1026       match_positions[j] = match_positions[j - 1] + 1;
1027 
1028     /* And fixup the rest. */
1029     for (; next < count; next++)
1030       match_positions[next] += delta;
1031   }
1032 
1033   buffer->move_to (end);
1034 
1035   return_trace (true);
1036 }
1037 
1038 
1039 
1040 /* Contextual lookups */
1041 
1042 struct ContextClosureLookupContext
1043 {
1044   ContextClosureFuncs funcs;
1045   const void *intersects_data;
1046 };
1047 
1048 struct ContextCollectGlyphsLookupContext
1049 {
1050   ContextCollectGlyphsFuncs funcs;
1051   const void *collect_data;
1052 };
1053 
1054 struct ContextApplyLookupContext
1055 {
1056   ContextApplyFuncs funcs;
1057   const void *match_data;
1058 };
1059 
context_closure_lookup(hb_closure_context_t * c,unsigned int inputCount,const USHORT input[],unsigned int lookupCount,const LookupRecord lookupRecord[],ContextClosureLookupContext & lookup_context)1060 static inline void context_closure_lookup (hb_closure_context_t *c,
1061 					   unsigned int inputCount, /* Including the first glyph (not matched) */
1062 					   const USHORT input[], /* Array of input values--start with second glyph */
1063 					   unsigned int lookupCount,
1064 					   const LookupRecord lookupRecord[],
1065 					   ContextClosureLookupContext &lookup_context)
1066 {
1067   if (intersects_array (c,
1068 			inputCount ? inputCount - 1 : 0, input,
1069 			lookup_context.funcs.intersects, lookup_context.intersects_data))
1070     recurse_lookups (c,
1071 		     lookupCount, lookupRecord);
1072 }
1073 
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)1074 static inline void context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1075 						  unsigned int inputCount, /* Including the first glyph (not matched) */
1076 						  const USHORT input[], /* Array of input values--start with second glyph */
1077 						  unsigned int lookupCount,
1078 						  const LookupRecord lookupRecord[],
1079 						  ContextCollectGlyphsLookupContext &lookup_context)
1080 {
1081   collect_array (c, c->input,
1082 		 inputCount ? inputCount - 1 : 0, input,
1083 		 lookup_context.funcs.collect, lookup_context.collect_data);
1084   recurse_lookups (c,
1085 		   lookupCount, lookupRecord);
1086 }
1087 
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)1088 static inline bool context_would_apply_lookup (hb_would_apply_context_t *c,
1089 					       unsigned int inputCount, /* Including the first glyph (not matched) */
1090 					       const USHORT input[], /* Array of input values--start with second glyph */
1091 					       unsigned int lookupCount HB_UNUSED,
1092 					       const LookupRecord lookupRecord[] HB_UNUSED,
1093 					       ContextApplyLookupContext &lookup_context)
1094 {
1095   return would_match_input (c,
1096 			    inputCount, input,
1097 			    lookup_context.funcs.match, lookup_context.match_data);
1098 }
context_apply_lookup(hb_apply_context_t * c,unsigned int inputCount,const USHORT input[],unsigned int lookupCount,const LookupRecord lookupRecord[],ContextApplyLookupContext & lookup_context)1099 static inline bool context_apply_lookup (hb_apply_context_t *c,
1100 					 unsigned int inputCount, /* Including the first glyph (not matched) */
1101 					 const USHORT input[], /* Array of input values--start with second glyph */
1102 					 unsigned int lookupCount,
1103 					 const LookupRecord lookupRecord[],
1104 					 ContextApplyLookupContext &lookup_context)
1105 {
1106   unsigned int match_length = 0;
1107   unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
1108   return match_input (c,
1109 		      inputCount, input,
1110 		      lookup_context.funcs.match, lookup_context.match_data,
1111 		      &match_length, match_positions)
1112       && apply_lookup (c,
1113 		       inputCount, match_positions,
1114 		       lookupCount, lookupRecord,
1115 		       match_length);
1116 }
1117 
1118 struct Rule
1119 {
closureOT::Rule1120   inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1121   {
1122     TRACE_CLOSURE (this);
1123     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1124     context_closure_lookup (c,
1125 			    inputCount, inputZ,
1126 			    lookupCount, lookupRecord,
1127 			    lookup_context);
1128   }
1129 
collect_glyphsOT::Rule1130   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1131   {
1132     TRACE_COLLECT_GLYPHS (this);
1133     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1134     context_collect_glyphs_lookup (c,
1135 				   inputCount, inputZ,
1136 				   lookupCount, lookupRecord,
1137 				   lookup_context);
1138   }
1139 
would_applyOT::Rule1140   inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1141   {
1142     TRACE_WOULD_APPLY (this);
1143     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1144     return_trace (context_would_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1145   }
1146 
applyOT::Rule1147   inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1148   {
1149     TRACE_APPLY (this);
1150     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1151     return_trace (context_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1152   }
1153 
1154   public:
sanitizeOT::Rule1155   inline bool sanitize (hb_sanitize_context_t *c) const
1156   {
1157     TRACE_SANITIZE (this);
1158     return inputCount.sanitize (c)
1159 	&& lookupCount.sanitize (c)
1160 	&& c->check_range (inputZ,
1161 			   inputZ[0].static_size * inputCount
1162 			   + lookupRecordX[0].static_size * lookupCount);
1163   }
1164 
1165   protected:
1166   USHORT	inputCount;		/* Total number of glyphs in input
1167 					 * glyph sequence--includes the first
1168 					 * glyph */
1169   USHORT	lookupCount;		/* Number of LookupRecords */
1170   USHORT	inputZ[VAR];		/* Array of match inputs--start with
1171 					 * second glyph */
1172   LookupRecord	lookupRecordX[VAR];	/* Array of LookupRecords--in
1173 					 * design order */
1174   public:
1175   DEFINE_SIZE_ARRAY2 (4, inputZ, lookupRecordX);
1176 };
1177 
1178 struct RuleSet
1179 {
closureOT::RuleSet1180   inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1181   {
1182     TRACE_CLOSURE (this);
1183     unsigned int num_rules = rule.len;
1184     for (unsigned int i = 0; i < num_rules; i++)
1185       (this+rule[i]).closure (c, lookup_context);
1186   }
1187 
collect_glyphsOT::RuleSet1188   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1189   {
1190     TRACE_COLLECT_GLYPHS (this);
1191     unsigned int num_rules = rule.len;
1192     for (unsigned int i = 0; i < num_rules; i++)
1193       (this+rule[i]).collect_glyphs (c, lookup_context);
1194   }
1195 
would_applyOT::RuleSet1196   inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1197   {
1198     TRACE_WOULD_APPLY (this);
1199     unsigned int num_rules = rule.len;
1200     for (unsigned int i = 0; i < num_rules; i++)
1201     {
1202       if ((this+rule[i]).would_apply (c, lookup_context))
1203         return_trace (true);
1204     }
1205     return_trace (false);
1206   }
1207 
applyOT::RuleSet1208   inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1209   {
1210     TRACE_APPLY (this);
1211     unsigned int num_rules = rule.len;
1212     for (unsigned int i = 0; i < num_rules; i++)
1213     {
1214       if ((this+rule[i]).apply (c, lookup_context))
1215         return_trace (true);
1216     }
1217     return_trace (false);
1218   }
1219 
sanitizeOT::RuleSet1220   inline bool sanitize (hb_sanitize_context_t *c) const
1221   {
1222     TRACE_SANITIZE (this);
1223     return_trace (rule.sanitize (c, this));
1224   }
1225 
1226   protected:
1227   OffsetArrayOf<Rule>
1228 		rule;			/* Array of Rule tables
1229 					 * ordered by preference */
1230   public:
1231   DEFINE_SIZE_ARRAY (2, rule);
1232 };
1233 
1234 
1235 struct ContextFormat1
1236 {
closureOT::ContextFormat11237   inline void closure (hb_closure_context_t *c) const
1238   {
1239     TRACE_CLOSURE (this);
1240 
1241     const Coverage &cov = (this+coverage);
1242 
1243     struct ContextClosureLookupContext lookup_context = {
1244       {intersects_glyph},
1245       NULL
1246     };
1247 
1248     unsigned int count = ruleSet.len;
1249     for (unsigned int i = 0; i < count; i++)
1250       if (cov.intersects_coverage (c->glyphs, i)) {
1251 	const RuleSet &rule_set = this+ruleSet[i];
1252 	rule_set.closure (c, lookup_context);
1253       }
1254   }
1255 
collect_glyphsOT::ContextFormat11256   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1257   {
1258     TRACE_COLLECT_GLYPHS (this);
1259     (this+coverage).add_coverage (c->input);
1260 
1261     struct ContextCollectGlyphsLookupContext lookup_context = {
1262       {collect_glyph},
1263       NULL
1264     };
1265 
1266     unsigned int count = ruleSet.len;
1267     for (unsigned int i = 0; i < count; i++)
1268       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1269   }
1270 
would_applyOT::ContextFormat11271   inline bool would_apply (hb_would_apply_context_t *c) const
1272   {
1273     TRACE_WOULD_APPLY (this);
1274 
1275     const RuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1276     struct ContextApplyLookupContext lookup_context = {
1277       {match_glyph},
1278       NULL
1279     };
1280     return_trace (rule_set.would_apply (c, lookup_context));
1281   }
1282 
get_coverageOT::ContextFormat11283   inline const Coverage &get_coverage (void) const
1284   {
1285     return this+coverage;
1286   }
1287 
applyOT::ContextFormat11288   inline bool apply (hb_apply_context_t *c) const
1289   {
1290     TRACE_APPLY (this);
1291     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1292     if (likely (index == NOT_COVERED))
1293       return_trace (false);
1294 
1295     const RuleSet &rule_set = this+ruleSet[index];
1296     struct ContextApplyLookupContext lookup_context = {
1297       {match_glyph},
1298       NULL
1299     };
1300     return_trace (rule_set.apply (c, lookup_context));
1301   }
1302 
sanitizeOT::ContextFormat11303   inline bool sanitize (hb_sanitize_context_t *c) const
1304   {
1305     TRACE_SANITIZE (this);
1306     return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1307   }
1308 
1309   protected:
1310   USHORT	format;			/* Format identifier--format = 1 */
1311   OffsetTo<Coverage>
1312 		coverage;		/* Offset to Coverage table--from
1313 					 * beginning of table */
1314   OffsetArrayOf<RuleSet>
1315 		ruleSet;		/* Array of RuleSet tables
1316 					 * ordered by Coverage Index */
1317   public:
1318   DEFINE_SIZE_ARRAY (6, ruleSet);
1319 };
1320 
1321 
1322 struct ContextFormat2
1323 {
closureOT::ContextFormat21324   inline void closure (hb_closure_context_t *c) const
1325   {
1326     TRACE_CLOSURE (this);
1327     if (!(this+coverage).intersects (c->glyphs))
1328       return;
1329 
1330     const ClassDef &class_def = this+classDef;
1331 
1332     struct ContextClosureLookupContext lookup_context = {
1333       {intersects_class},
1334       &class_def
1335     };
1336 
1337     unsigned int count = ruleSet.len;
1338     for (unsigned int i = 0; i < count; i++)
1339       if (class_def.intersects_class (c->glyphs, i)) {
1340 	const RuleSet &rule_set = this+ruleSet[i];
1341 	rule_set.closure (c, lookup_context);
1342       }
1343   }
1344 
collect_glyphsOT::ContextFormat21345   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1346   {
1347     TRACE_COLLECT_GLYPHS (this);
1348     (this+coverage).add_coverage (c->input);
1349 
1350     const ClassDef &class_def = this+classDef;
1351     struct ContextCollectGlyphsLookupContext lookup_context = {
1352       {collect_class},
1353       &class_def
1354     };
1355 
1356     unsigned int count = ruleSet.len;
1357     for (unsigned int i = 0; i < count; i++)
1358       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1359   }
1360 
would_applyOT::ContextFormat21361   inline bool would_apply (hb_would_apply_context_t *c) const
1362   {
1363     TRACE_WOULD_APPLY (this);
1364 
1365     const ClassDef &class_def = this+classDef;
1366     unsigned int index = class_def.get_class (c->glyphs[0]);
1367     const RuleSet &rule_set = this+ruleSet[index];
1368     struct ContextApplyLookupContext lookup_context = {
1369       {match_class},
1370       &class_def
1371     };
1372     return_trace (rule_set.would_apply (c, lookup_context));
1373   }
1374 
get_coverageOT::ContextFormat21375   inline const Coverage &get_coverage (void) const
1376   {
1377     return this+coverage;
1378   }
1379 
applyOT::ContextFormat21380   inline bool apply (hb_apply_context_t *c) const
1381   {
1382     TRACE_APPLY (this);
1383     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1384     if (likely (index == NOT_COVERED)) return_trace (false);
1385 
1386     const ClassDef &class_def = this+classDef;
1387     index = class_def.get_class (c->buffer->cur().codepoint);
1388     const RuleSet &rule_set = this+ruleSet[index];
1389     struct ContextApplyLookupContext lookup_context = {
1390       {match_class},
1391       &class_def
1392     };
1393     return_trace (rule_set.apply (c, lookup_context));
1394   }
1395 
sanitizeOT::ContextFormat21396   inline bool sanitize (hb_sanitize_context_t *c) const
1397   {
1398     TRACE_SANITIZE (this);
1399     return_trace (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this));
1400   }
1401 
1402   protected:
1403   USHORT	format;			/* Format identifier--format = 2 */
1404   OffsetTo<Coverage>
1405 		coverage;		/* Offset to Coverage table--from
1406 					 * beginning of table */
1407   OffsetTo<ClassDef>
1408 		classDef;		/* Offset to glyph ClassDef table--from
1409 					 * beginning of table */
1410   OffsetArrayOf<RuleSet>
1411 		ruleSet;		/* Array of RuleSet tables
1412 					 * ordered by class */
1413   public:
1414   DEFINE_SIZE_ARRAY (8, ruleSet);
1415 };
1416 
1417 
1418 struct ContextFormat3
1419 {
closureOT::ContextFormat31420   inline void closure (hb_closure_context_t *c) const
1421   {
1422     TRACE_CLOSURE (this);
1423     if (!(this+coverageZ[0]).intersects (c->glyphs))
1424       return;
1425 
1426     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1427     struct ContextClosureLookupContext lookup_context = {
1428       {intersects_coverage},
1429       this
1430     };
1431     context_closure_lookup (c,
1432 			    glyphCount, (const USHORT *) (coverageZ + 1),
1433 			    lookupCount, lookupRecord,
1434 			    lookup_context);
1435   }
1436 
collect_glyphsOT::ContextFormat31437   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1438   {
1439     TRACE_COLLECT_GLYPHS (this);
1440     (this+coverageZ[0]).add_coverage (c->input);
1441 
1442     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1443     struct ContextCollectGlyphsLookupContext lookup_context = {
1444       {collect_coverage},
1445       this
1446     };
1447 
1448     context_collect_glyphs_lookup (c,
1449 				   glyphCount, (const USHORT *) (coverageZ + 1),
1450 				   lookupCount, lookupRecord,
1451 				   lookup_context);
1452   }
1453 
would_applyOT::ContextFormat31454   inline bool would_apply (hb_would_apply_context_t *c) const
1455   {
1456     TRACE_WOULD_APPLY (this);
1457 
1458     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1459     struct ContextApplyLookupContext lookup_context = {
1460       {match_coverage},
1461       this
1462     };
1463     return_trace (context_would_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1464   }
1465 
get_coverageOT::ContextFormat31466   inline const Coverage &get_coverage (void) const
1467   {
1468     return this+coverageZ[0];
1469   }
1470 
applyOT::ContextFormat31471   inline bool apply (hb_apply_context_t *c) const
1472   {
1473     TRACE_APPLY (this);
1474     unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint);
1475     if (likely (index == NOT_COVERED)) return_trace (false);
1476 
1477     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1478     struct ContextApplyLookupContext lookup_context = {
1479       {match_coverage},
1480       this
1481     };
1482     return_trace (context_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1483   }
1484 
sanitizeOT::ContextFormat31485   inline bool sanitize (hb_sanitize_context_t *c) const
1486   {
1487     TRACE_SANITIZE (this);
1488     if (!c->check_struct (this)) return_trace (false);
1489     unsigned int count = glyphCount;
1490     if (!count) return_trace (false); /* We want to access coverageZ[0] freely. */
1491     if (!c->check_array (coverageZ, coverageZ[0].static_size, count)) return_trace (false);
1492     for (unsigned int i = 0; i < count; i++)
1493       if (!coverageZ[i].sanitize (c, this)) return_trace (false);
1494     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * count);
1495     return_trace (c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount));
1496   }
1497 
1498   protected:
1499   USHORT	format;			/* Format identifier--format = 3 */
1500   USHORT	glyphCount;		/* Number of glyphs in the input glyph
1501 					 * sequence */
1502   USHORT	lookupCount;		/* Number of LookupRecords */
1503   OffsetTo<Coverage>
1504 		coverageZ[VAR];		/* Array of offsets to Coverage
1505 					 * table in glyph sequence order */
1506   LookupRecord	lookupRecordX[VAR];	/* Array of LookupRecords--in
1507 					 * design order */
1508   public:
1509   DEFINE_SIZE_ARRAY2 (6, coverageZ, lookupRecordX);
1510 };
1511 
1512 struct Context
1513 {
1514   template <typename context_t>
dispatchOT::Context1515   inline typename context_t::return_t dispatch (context_t *c) const
1516   {
1517     TRACE_DISPATCH (this, u.format);
1518     if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1519     switch (u.format) {
1520     case 1: return_trace (c->dispatch (u.format1));
1521     case 2: return_trace (c->dispatch (u.format2));
1522     case 3: return_trace (c->dispatch (u.format3));
1523     default:return_trace (c->default_return_value ());
1524     }
1525   }
1526 
1527   protected:
1528   union {
1529   USHORT		format;		/* Format identifier */
1530   ContextFormat1	format1;
1531   ContextFormat2	format2;
1532   ContextFormat3	format3;
1533   } u;
1534 };
1535 
1536 
1537 /* Chaining Contextual lookups */
1538 
1539 struct ChainContextClosureLookupContext
1540 {
1541   ContextClosureFuncs funcs;
1542   const void *intersects_data[3];
1543 };
1544 
1545 struct ChainContextCollectGlyphsLookupContext
1546 {
1547   ContextCollectGlyphsFuncs funcs;
1548   const void *collect_data[3];
1549 };
1550 
1551 struct ChainContextApplyLookupContext
1552 {
1553   ContextApplyFuncs funcs;
1554   const void *match_data[3];
1555 };
1556 
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)1557 static inline void chain_context_closure_lookup (hb_closure_context_t *c,
1558 						 unsigned int backtrackCount,
1559 						 const USHORT backtrack[],
1560 						 unsigned int inputCount, /* Including the first glyph (not matched) */
1561 						 const USHORT input[], /* Array of input values--start with second glyph */
1562 						 unsigned int lookaheadCount,
1563 						 const USHORT lookahead[],
1564 						 unsigned int lookupCount,
1565 						 const LookupRecord lookupRecord[],
1566 						 ChainContextClosureLookupContext &lookup_context)
1567 {
1568   if (intersects_array (c,
1569 			backtrackCount, backtrack,
1570 			lookup_context.funcs.intersects, lookup_context.intersects_data[0])
1571    && intersects_array (c,
1572 			inputCount ? inputCount - 1 : 0, input,
1573 			lookup_context.funcs.intersects, lookup_context.intersects_data[1])
1574    && intersects_array (c,
1575 		       lookaheadCount, lookahead,
1576 		       lookup_context.funcs.intersects, lookup_context.intersects_data[2]))
1577     recurse_lookups (c,
1578 		     lookupCount, lookupRecord);
1579 }
1580 
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)1581 static inline void chain_context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1582 						        unsigned int backtrackCount,
1583 						        const USHORT backtrack[],
1584 						        unsigned int inputCount, /* Including the first glyph (not matched) */
1585 						        const USHORT input[], /* Array of input values--start with second glyph */
1586 						        unsigned int lookaheadCount,
1587 						        const USHORT lookahead[],
1588 						        unsigned int lookupCount,
1589 						        const LookupRecord lookupRecord[],
1590 						        ChainContextCollectGlyphsLookupContext &lookup_context)
1591 {
1592   collect_array (c, c->before,
1593 		 backtrackCount, backtrack,
1594 		 lookup_context.funcs.collect, lookup_context.collect_data[0]);
1595   collect_array (c, c->input,
1596 		 inputCount ? inputCount - 1 : 0, input,
1597 		 lookup_context.funcs.collect, lookup_context.collect_data[1]);
1598   collect_array (c, c->after,
1599 		 lookaheadCount, lookahead,
1600 		 lookup_context.funcs.collect, lookup_context.collect_data[2]);
1601   recurse_lookups (c,
1602 		   lookupCount, lookupRecord);
1603 }
1604 
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)1605 static inline bool chain_context_would_apply_lookup (hb_would_apply_context_t *c,
1606 						     unsigned int backtrackCount,
1607 						     const USHORT backtrack[] HB_UNUSED,
1608 						     unsigned int inputCount, /* Including the first glyph (not matched) */
1609 						     const USHORT input[], /* Array of input values--start with second glyph */
1610 						     unsigned int lookaheadCount,
1611 						     const USHORT lookahead[] HB_UNUSED,
1612 						     unsigned int lookupCount HB_UNUSED,
1613 						     const LookupRecord lookupRecord[] HB_UNUSED,
1614 						     ChainContextApplyLookupContext &lookup_context)
1615 {
1616   return (c->zero_context ? !backtrackCount && !lookaheadCount : true)
1617       && would_match_input (c,
1618 			    inputCount, input,
1619 			    lookup_context.funcs.match, lookup_context.match_data[1]);
1620 }
1621 
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)1622 static inline bool chain_context_apply_lookup (hb_apply_context_t *c,
1623 					       unsigned int backtrackCount,
1624 					       const USHORT backtrack[],
1625 					       unsigned int inputCount, /* Including the first glyph (not matched) */
1626 					       const USHORT input[], /* Array of input values--start with second glyph */
1627 					       unsigned int lookaheadCount,
1628 					       const USHORT lookahead[],
1629 					       unsigned int lookupCount,
1630 					       const LookupRecord lookupRecord[],
1631 					       ChainContextApplyLookupContext &lookup_context)
1632 {
1633   unsigned int match_length = 0;
1634   unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
1635   return match_input (c,
1636 		      inputCount, input,
1637 		      lookup_context.funcs.match, lookup_context.match_data[1],
1638 		      &match_length, match_positions)
1639       && match_backtrack (c,
1640 			  backtrackCount, backtrack,
1641 			  lookup_context.funcs.match, lookup_context.match_data[0])
1642       && match_lookahead (c,
1643 			  lookaheadCount, lookahead,
1644 			  lookup_context.funcs.match, lookup_context.match_data[2],
1645 			  match_length)
1646       && apply_lookup (c,
1647 		       inputCount, match_positions,
1648 		       lookupCount, lookupRecord,
1649 		       match_length);
1650 }
1651 
1652 struct ChainRule
1653 {
closureOT::ChainRule1654   inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1655   {
1656     TRACE_CLOSURE (this);
1657     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1658     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1659     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1660     chain_context_closure_lookup (c,
1661 				  backtrack.len, backtrack.array,
1662 				  input.len, input.array,
1663 				  lookahead.len, lookahead.array,
1664 				  lookup.len, lookup.array,
1665 				  lookup_context);
1666   }
1667 
collect_glyphsOT::ChainRule1668   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1669   {
1670     TRACE_COLLECT_GLYPHS (this);
1671     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1672     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1673     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1674     chain_context_collect_glyphs_lookup (c,
1675 					 backtrack.len, backtrack.array,
1676 					 input.len, input.array,
1677 					 lookahead.len, lookahead.array,
1678 					 lookup.len, lookup.array,
1679 					 lookup_context);
1680   }
1681 
would_applyOT::ChainRule1682   inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1683   {
1684     TRACE_WOULD_APPLY (this);
1685     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1686     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1687     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1688     return_trace (chain_context_would_apply_lookup (c,
1689 						    backtrack.len, backtrack.array,
1690 						    input.len, input.array,
1691 						    lookahead.len, lookahead.array, lookup.len,
1692 						    lookup.array, lookup_context));
1693   }
1694 
applyOT::ChainRule1695   inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1696   {
1697     TRACE_APPLY (this);
1698     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1699     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1700     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1701     return_trace (chain_context_apply_lookup (c,
1702 					      backtrack.len, backtrack.array,
1703 					      input.len, input.array,
1704 					      lookahead.len, lookahead.array, lookup.len,
1705 					      lookup.array, lookup_context));
1706   }
1707 
sanitizeOT::ChainRule1708   inline bool sanitize (hb_sanitize_context_t *c) const
1709   {
1710     TRACE_SANITIZE (this);
1711     if (!backtrack.sanitize (c)) return_trace (false);
1712     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1713     if (!input.sanitize (c)) return_trace (false);
1714     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1715     if (!lookahead.sanitize (c)) return_trace (false);
1716     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1717     return_trace (lookup.sanitize (c));
1718   }
1719 
1720   protected:
1721   ArrayOf<USHORT>
1722 		backtrack;		/* Array of backtracking values
1723 					 * (to be matched before the input
1724 					 * sequence) */
1725   HeadlessArrayOf<USHORT>
1726 		inputX;			/* Array of input values (start with
1727 					 * second glyph) */
1728   ArrayOf<USHORT>
1729 		lookaheadX;		/* Array of lookahead values's (to be
1730 					 * matched after the input sequence) */
1731   ArrayOf<LookupRecord>
1732 		lookupX;		/* Array of LookupRecords--in
1733 					 * design order) */
1734   public:
1735   DEFINE_SIZE_MIN (8);
1736 };
1737 
1738 struct ChainRuleSet
1739 {
closureOT::ChainRuleSet1740   inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1741   {
1742     TRACE_CLOSURE (this);
1743     unsigned int num_rules = rule.len;
1744     for (unsigned int i = 0; i < num_rules; i++)
1745       (this+rule[i]).closure (c, lookup_context);
1746   }
1747 
collect_glyphsOT::ChainRuleSet1748   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1749   {
1750     TRACE_COLLECT_GLYPHS (this);
1751     unsigned int num_rules = rule.len;
1752     for (unsigned int i = 0; i < num_rules; i++)
1753       (this+rule[i]).collect_glyphs (c, lookup_context);
1754   }
1755 
would_applyOT::ChainRuleSet1756   inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1757   {
1758     TRACE_WOULD_APPLY (this);
1759     unsigned int num_rules = rule.len;
1760     for (unsigned int i = 0; i < num_rules; i++)
1761       if ((this+rule[i]).would_apply (c, lookup_context))
1762         return_trace (true);
1763 
1764     return_trace (false);
1765   }
1766 
applyOT::ChainRuleSet1767   inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1768   {
1769     TRACE_APPLY (this);
1770     unsigned int num_rules = rule.len;
1771     for (unsigned int i = 0; i < num_rules; i++)
1772       if ((this+rule[i]).apply (c, lookup_context))
1773         return_trace (true);
1774 
1775     return_trace (false);
1776   }
1777 
sanitizeOT::ChainRuleSet1778   inline bool sanitize (hb_sanitize_context_t *c) const
1779   {
1780     TRACE_SANITIZE (this);
1781     return_trace (rule.sanitize (c, this));
1782   }
1783 
1784   protected:
1785   OffsetArrayOf<ChainRule>
1786 		rule;			/* Array of ChainRule tables
1787 					 * ordered by preference */
1788   public:
1789   DEFINE_SIZE_ARRAY (2, rule);
1790 };
1791 
1792 struct ChainContextFormat1
1793 {
closureOT::ChainContextFormat11794   inline void closure (hb_closure_context_t *c) const
1795   {
1796     TRACE_CLOSURE (this);
1797     const Coverage &cov = (this+coverage);
1798 
1799     struct ChainContextClosureLookupContext lookup_context = {
1800       {intersects_glyph},
1801       {NULL, NULL, NULL}
1802     };
1803 
1804     unsigned int count = ruleSet.len;
1805     for (unsigned int i = 0; i < count; i++)
1806       if (cov.intersects_coverage (c->glyphs, i)) {
1807 	const ChainRuleSet &rule_set = this+ruleSet[i];
1808 	rule_set.closure (c, lookup_context);
1809       }
1810   }
1811 
collect_glyphsOT::ChainContextFormat11812   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1813   {
1814     TRACE_COLLECT_GLYPHS (this);
1815     (this+coverage).add_coverage (c->input);
1816 
1817     struct ChainContextCollectGlyphsLookupContext lookup_context = {
1818       {collect_glyph},
1819       {NULL, NULL, NULL}
1820     };
1821 
1822     unsigned int count = ruleSet.len;
1823     for (unsigned int i = 0; i < count; i++)
1824       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1825   }
1826 
would_applyOT::ChainContextFormat11827   inline bool would_apply (hb_would_apply_context_t *c) const
1828   {
1829     TRACE_WOULD_APPLY (this);
1830 
1831     const ChainRuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1832     struct ChainContextApplyLookupContext lookup_context = {
1833       {match_glyph},
1834       {NULL, NULL, NULL}
1835     };
1836     return_trace (rule_set.would_apply (c, lookup_context));
1837   }
1838 
get_coverageOT::ChainContextFormat11839   inline const Coverage &get_coverage (void) const
1840   {
1841     return this+coverage;
1842   }
1843 
applyOT::ChainContextFormat11844   inline bool apply (hb_apply_context_t *c) const
1845   {
1846     TRACE_APPLY (this);
1847     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1848     if (likely (index == NOT_COVERED)) return_trace (false);
1849 
1850     const ChainRuleSet &rule_set = this+ruleSet[index];
1851     struct ChainContextApplyLookupContext lookup_context = {
1852       {match_glyph},
1853       {NULL, NULL, NULL}
1854     };
1855     return_trace (rule_set.apply (c, lookup_context));
1856   }
1857 
sanitizeOT::ChainContextFormat11858   inline bool sanitize (hb_sanitize_context_t *c) const
1859   {
1860     TRACE_SANITIZE (this);
1861     return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1862   }
1863 
1864   protected:
1865   USHORT	format;			/* Format identifier--format = 1 */
1866   OffsetTo<Coverage>
1867 		coverage;		/* Offset to Coverage table--from
1868 					 * beginning of table */
1869   OffsetArrayOf<ChainRuleSet>
1870 		ruleSet;		/* Array of ChainRuleSet tables
1871 					 * ordered by Coverage Index */
1872   public:
1873   DEFINE_SIZE_ARRAY (6, ruleSet);
1874 };
1875 
1876 struct ChainContextFormat2
1877 {
closureOT::ChainContextFormat21878   inline void closure (hb_closure_context_t *c) const
1879   {
1880     TRACE_CLOSURE (this);
1881     if (!(this+coverage).intersects (c->glyphs))
1882       return;
1883 
1884     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1885     const ClassDef &input_class_def = this+inputClassDef;
1886     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1887 
1888     struct ChainContextClosureLookupContext lookup_context = {
1889       {intersects_class},
1890       {&backtrack_class_def,
1891        &input_class_def,
1892        &lookahead_class_def}
1893     };
1894 
1895     unsigned int count = ruleSet.len;
1896     for (unsigned int i = 0; i < count; i++)
1897       if (input_class_def.intersects_class (c->glyphs, i)) {
1898 	const ChainRuleSet &rule_set = this+ruleSet[i];
1899 	rule_set.closure (c, lookup_context);
1900       }
1901   }
1902 
collect_glyphsOT::ChainContextFormat21903   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1904   {
1905     TRACE_COLLECT_GLYPHS (this);
1906     (this+coverage).add_coverage (c->input);
1907 
1908     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1909     const ClassDef &input_class_def = this+inputClassDef;
1910     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1911 
1912     struct ChainContextCollectGlyphsLookupContext lookup_context = {
1913       {collect_class},
1914       {&backtrack_class_def,
1915        &input_class_def,
1916        &lookahead_class_def}
1917     };
1918 
1919     unsigned int count = ruleSet.len;
1920     for (unsigned int i = 0; i < count; i++)
1921       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1922   }
1923 
would_applyOT::ChainContextFormat21924   inline bool would_apply (hb_would_apply_context_t *c) const
1925   {
1926     TRACE_WOULD_APPLY (this);
1927 
1928     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1929     const ClassDef &input_class_def = this+inputClassDef;
1930     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1931 
1932     unsigned int index = input_class_def.get_class (c->glyphs[0]);
1933     const ChainRuleSet &rule_set = this+ruleSet[index];
1934     struct ChainContextApplyLookupContext lookup_context = {
1935       {match_class},
1936       {&backtrack_class_def,
1937        &input_class_def,
1938        &lookahead_class_def}
1939     };
1940     return_trace (rule_set.would_apply (c, lookup_context));
1941   }
1942 
get_coverageOT::ChainContextFormat21943   inline const Coverage &get_coverage (void) const
1944   {
1945     return this+coverage;
1946   }
1947 
applyOT::ChainContextFormat21948   inline bool apply (hb_apply_context_t *c) const
1949   {
1950     TRACE_APPLY (this);
1951     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1952     if (likely (index == NOT_COVERED)) return_trace (false);
1953 
1954     const ClassDef &backtrack_class_def = this+backtrackClassDef;
1955     const ClassDef &input_class_def = this+inputClassDef;
1956     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1957 
1958     index = input_class_def.get_class (c->buffer->cur().codepoint);
1959     const ChainRuleSet &rule_set = this+ruleSet[index];
1960     struct ChainContextApplyLookupContext lookup_context = {
1961       {match_class},
1962       {&backtrack_class_def,
1963        &input_class_def,
1964        &lookahead_class_def}
1965     };
1966     return_trace (rule_set.apply (c, lookup_context));
1967   }
1968 
sanitizeOT::ChainContextFormat21969   inline bool sanitize (hb_sanitize_context_t *c) const
1970   {
1971     TRACE_SANITIZE (this);
1972     return_trace (coverage.sanitize (c, this) &&
1973 		  backtrackClassDef.sanitize (c, this) &&
1974 		  inputClassDef.sanitize (c, this) &&
1975 		  lookaheadClassDef.sanitize (c, this) &&
1976 		  ruleSet.sanitize (c, this));
1977   }
1978 
1979   protected:
1980   USHORT	format;			/* Format identifier--format = 2 */
1981   OffsetTo<Coverage>
1982 		coverage;		/* Offset to Coverage table--from
1983 					 * beginning of table */
1984   OffsetTo<ClassDef>
1985 		backtrackClassDef;	/* Offset to glyph ClassDef table
1986 					 * containing backtrack sequence
1987 					 * data--from beginning of table */
1988   OffsetTo<ClassDef>
1989 		inputClassDef;		/* Offset to glyph ClassDef
1990 					 * table containing input sequence
1991 					 * data--from beginning of table */
1992   OffsetTo<ClassDef>
1993 		lookaheadClassDef;	/* Offset to glyph ClassDef table
1994 					 * containing lookahead sequence
1995 					 * data--from beginning of table */
1996   OffsetArrayOf<ChainRuleSet>
1997 		ruleSet;		/* Array of ChainRuleSet tables
1998 					 * ordered by class */
1999   public:
2000   DEFINE_SIZE_ARRAY (12, ruleSet);
2001 };
2002 
2003 struct ChainContextFormat3
2004 {
closureOT::ChainContextFormat32005   inline void closure (hb_closure_context_t *c) const
2006   {
2007     TRACE_CLOSURE (this);
2008     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2009 
2010     if (!(this+input[0]).intersects (c->glyphs))
2011       return;
2012 
2013     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2014     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2015     struct ChainContextClosureLookupContext lookup_context = {
2016       {intersects_coverage},
2017       {this, this, this}
2018     };
2019     chain_context_closure_lookup (c,
2020 				  backtrack.len, (const USHORT *) backtrack.array,
2021 				  input.len, (const USHORT *) input.array + 1,
2022 				  lookahead.len, (const USHORT *) lookahead.array,
2023 				  lookup.len, lookup.array,
2024 				  lookup_context);
2025   }
2026 
collect_glyphsOT::ChainContextFormat32027   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
2028   {
2029     TRACE_COLLECT_GLYPHS (this);
2030     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2031 
2032     (this+input[0]).add_coverage (c->input);
2033 
2034     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2035     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2036     struct ChainContextCollectGlyphsLookupContext lookup_context = {
2037       {collect_coverage},
2038       {this, this, this}
2039     };
2040     chain_context_collect_glyphs_lookup (c,
2041 					 backtrack.len, (const USHORT *) backtrack.array,
2042 					 input.len, (const USHORT *) input.array + 1,
2043 					 lookahead.len, (const USHORT *) lookahead.array,
2044 					 lookup.len, lookup.array,
2045 					 lookup_context);
2046   }
2047 
would_applyOT::ChainContextFormat32048   inline bool would_apply (hb_would_apply_context_t *c) const
2049   {
2050     TRACE_WOULD_APPLY (this);
2051 
2052     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2053     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2054     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2055     struct ChainContextApplyLookupContext lookup_context = {
2056       {match_coverage},
2057       {this, this, this}
2058     };
2059     return_trace (chain_context_would_apply_lookup (c,
2060 						    backtrack.len, (const USHORT *) backtrack.array,
2061 						    input.len, (const USHORT *) input.array + 1,
2062 						    lookahead.len, (const USHORT *) lookahead.array,
2063 						    lookup.len, lookup.array, lookup_context));
2064   }
2065 
get_coverageOT::ChainContextFormat32066   inline const Coverage &get_coverage (void) const
2067   {
2068     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2069     return this+input[0];
2070   }
2071 
applyOT::ChainContextFormat32072   inline bool apply (hb_apply_context_t *c) const
2073   {
2074     TRACE_APPLY (this);
2075     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2076 
2077     unsigned int index = (this+input[0]).get_coverage (c->buffer->cur().codepoint);
2078     if (likely (index == NOT_COVERED)) return_trace (false);
2079 
2080     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2081     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2082     struct ChainContextApplyLookupContext lookup_context = {
2083       {match_coverage},
2084       {this, this, this}
2085     };
2086     return_trace (chain_context_apply_lookup (c,
2087 					      backtrack.len, (const USHORT *) backtrack.array,
2088 					      input.len, (const USHORT *) input.array + 1,
2089 					      lookahead.len, (const USHORT *) lookahead.array,
2090 					      lookup.len, lookup.array, lookup_context));
2091   }
2092 
sanitizeOT::ChainContextFormat32093   inline bool sanitize (hb_sanitize_context_t *c) const
2094   {
2095     TRACE_SANITIZE (this);
2096     if (!backtrack.sanitize (c, this)) return_trace (false);
2097     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2098     if (!input.sanitize (c, this)) return_trace (false);
2099     if (!input.len) return_trace (false); /* To be consistent with Context. */
2100     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2101     if (!lookahead.sanitize (c, this)) return_trace (false);
2102     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2103     return_trace (lookup.sanitize (c));
2104   }
2105 
2106   protected:
2107   USHORT	format;			/* Format identifier--format = 3 */
2108   OffsetArrayOf<Coverage>
2109 		backtrack;		/* Array of coverage tables
2110 					 * in backtracking sequence, in  glyph
2111 					 * sequence order */
2112   OffsetArrayOf<Coverage>
2113 		inputX		;	/* Array of coverage
2114 					 * tables in input sequence, in glyph
2115 					 * sequence order */
2116   OffsetArrayOf<Coverage>
2117 		lookaheadX;		/* Array of coverage tables
2118 					 * in lookahead sequence, in glyph
2119 					 * sequence order */
2120   ArrayOf<LookupRecord>
2121 		lookupX;		/* Array of LookupRecords--in
2122 					 * design order) */
2123   public:
2124   DEFINE_SIZE_MIN (10);
2125 };
2126 
2127 struct ChainContext
2128 {
2129   template <typename context_t>
dispatchOT::ChainContext2130   inline typename context_t::return_t dispatch (context_t *c) const
2131   {
2132     TRACE_DISPATCH (this, u.format);
2133     if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
2134     switch (u.format) {
2135     case 1: return_trace (c->dispatch (u.format1));
2136     case 2: return_trace (c->dispatch (u.format2));
2137     case 3: return_trace (c->dispatch (u.format3));
2138     default:return_trace (c->default_return_value ());
2139     }
2140   }
2141 
2142   protected:
2143   union {
2144   USHORT		format;	/* Format identifier */
2145   ChainContextFormat1	format1;
2146   ChainContextFormat2	format2;
2147   ChainContextFormat3	format3;
2148   } u;
2149 };
2150 
2151 
2152 template <typename T>
2153 struct ExtensionFormat1
2154 {
get_typeOT::ExtensionFormat12155   inline unsigned int get_type (void) const { return extensionLookupType; }
2156 
2157   template <typename X>
get_subtableOT::ExtensionFormat12158   inline const X& get_subtable (void) const
2159   {
2160     unsigned int offset = extensionOffset;
2161     if (unlikely (!offset)) return Null(typename T::LookupSubTable);
2162     return StructAtOffset<typename T::LookupSubTable> (this, offset);
2163   }
2164 
2165   template <typename context_t>
dispatchOT::ExtensionFormat12166   inline typename context_t::return_t dispatch (context_t *c) const
2167   {
2168     TRACE_DISPATCH (this, format);
2169     if (unlikely (!c->may_dispatch (this, this))) return_trace (c->no_dispatch_return_value ());
2170     return_trace (get_subtable<typename T::LookupSubTable> ().dispatch (c, get_type ()));
2171   }
2172 
2173   /* This is called from may_dispatch() above with hb_sanitize_context_t. */
sanitizeOT::ExtensionFormat12174   inline bool sanitize (hb_sanitize_context_t *c) const
2175   {
2176     TRACE_SANITIZE (this);
2177     return_trace (c->check_struct (this) && extensionOffset != 0);
2178   }
2179 
2180   protected:
2181   USHORT	format;			/* Format identifier. Set to 1. */
2182   USHORT	extensionLookupType;	/* Lookup type of subtable referenced
2183 					 * by ExtensionOffset (i.e. the
2184 					 * extension subtable). */
2185   ULONG		extensionOffset;	/* Offset to the extension subtable,
2186 					 * of lookup type subtable. */
2187   public:
2188   DEFINE_SIZE_STATIC (8);
2189 };
2190 
2191 template <typename T>
2192 struct Extension
2193 {
get_typeOT::Extension2194   inline unsigned int get_type (void) const
2195   {
2196     switch (u.format) {
2197     case 1: return u.format1.get_type ();
2198     default:return 0;
2199     }
2200   }
2201   template <typename X>
get_subtableOT::Extension2202   inline const X& get_subtable (void) const
2203   {
2204     switch (u.format) {
2205     case 1: return u.format1.template get_subtable<typename T::LookupSubTable> ();
2206     default:return Null(typename T::LookupSubTable);
2207     }
2208   }
2209 
2210   template <typename context_t>
dispatchOT::Extension2211   inline typename context_t::return_t dispatch (context_t *c) const
2212   {
2213     TRACE_DISPATCH (this, u.format);
2214     if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
2215     switch (u.format) {
2216     case 1: return_trace (u.format1.dispatch (c));
2217     default:return_trace (c->default_return_value ());
2218     }
2219   }
2220 
2221   protected:
2222   union {
2223   USHORT		format;		/* Format identifier */
2224   ExtensionFormat1<T>	format1;
2225   } u;
2226 };
2227 
2228 
2229 /*
2230  * GSUB/GPOS Common
2231  */
2232 
2233 struct GSUBGPOS
2234 {
2235   static const hb_tag_t GSUBTag	= HB_OT_TAG_GSUB;
2236   static const hb_tag_t GPOSTag	= HB_OT_TAG_GPOS;
2237 
get_script_countOT::GSUBGPOS2238   inline unsigned int get_script_count (void) const
2239   { return (this+scriptList).len; }
get_script_tagOT::GSUBGPOS2240   inline const Tag& get_script_tag (unsigned int i) const
2241   { return (this+scriptList).get_tag (i); }
get_script_tagsOT::GSUBGPOS2242   inline unsigned int get_script_tags (unsigned int start_offset,
2243 				       unsigned int *script_count /* IN/OUT */,
2244 				       hb_tag_t     *script_tags /* OUT */) const
2245   { return (this+scriptList).get_tags (start_offset, script_count, script_tags); }
get_scriptOT::GSUBGPOS2246   inline const Script& get_script (unsigned int i) const
2247   { return (this+scriptList)[i]; }
find_script_indexOT::GSUBGPOS2248   inline bool find_script_index (hb_tag_t tag, unsigned int *index) const
2249   { return (this+scriptList).find_index (tag, index); }
2250 
get_feature_countOT::GSUBGPOS2251   inline unsigned int get_feature_count (void) const
2252   { return (this+featureList).len; }
get_feature_tagOT::GSUBGPOS2253   inline hb_tag_t get_feature_tag (unsigned int i) const
2254   { return i == Index::NOT_FOUND_INDEX ? HB_TAG_NONE : (this+featureList).get_tag (i); }
get_feature_tagsOT::GSUBGPOS2255   inline unsigned int get_feature_tags (unsigned int start_offset,
2256 					unsigned int *feature_count /* IN/OUT */,
2257 					hb_tag_t     *feature_tags /* OUT */) const
2258   { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); }
get_featureOT::GSUBGPOS2259   inline const Feature& get_feature (unsigned int i) const
2260   { return (this+featureList)[i]; }
find_feature_indexOT::GSUBGPOS2261   inline bool find_feature_index (hb_tag_t tag, unsigned int *index) const
2262   { return (this+featureList).find_index (tag, index); }
2263 
get_lookup_countOT::GSUBGPOS2264   inline unsigned int get_lookup_count (void) const
2265   { return (this+lookupList).len; }
get_lookupOT::GSUBGPOS2266   inline const Lookup& get_lookup (unsigned int i) const
2267   { return (this+lookupList)[i]; }
2268 
sanitizeOT::GSUBGPOS2269   inline bool sanitize (hb_sanitize_context_t *c) const
2270   {
2271     TRACE_SANITIZE (this);
2272     return_trace (version.sanitize (c) &&
2273 		  likely (version.major == 1) &&
2274 		  scriptList.sanitize (c, this) &&
2275 		  featureList.sanitize (c, this) &&
2276 		  lookupList.sanitize (c, this));
2277   }
2278 
2279   protected:
2280   FixedVersion<>version;	/* Version of the GSUB/GPOS table--initially set
2281 				 * to 0x00010000u */
2282   OffsetTo<ScriptList>
2283 		scriptList;  	/* ScriptList table */
2284   OffsetTo<FeatureList>
2285 		featureList; 	/* FeatureList table */
2286   OffsetTo<LookupList>
2287 		lookupList; 	/* LookupList table */
2288   public:
2289   DEFINE_SIZE_STATIC (10);
2290 };
2291 
2292 
2293 } /* namespace OT */
2294 
2295 
2296 #endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */
2297