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 {
52 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>
55 inline return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; }
56 static return_t default_return_value (void) { return HB_VOID; }
57 bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
58 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
75 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
84 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 {
101 inline const char *get_name (void) { return "WOULD_APPLY"; }
102 template <typename T>
103 inline return_t dispatch (const T &obj) { return obj.would_apply (this); }
104 static return_t default_return_value (void) { return false; }
105 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
113 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 {
138 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>
141 inline return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
142 static return_t default_return_value (void) { return HB_VOID; }
143 bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
144 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
194 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 }
212 ~hb_collect_glyphs_context_t (void)
213 {
214 recursed_lookups.fini ();
215 }
216
217 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 {
232 inline const char *get_name (void) { return "GET_COVERAGE"; }
233 typedef const Coverage &return_t;
234 template <typename T>
235 inline return_t dispatch (const T &obj) { return obj.get_coverage (); }
236 static return_t default_return_value (void) { return Null(Coverage); }
237 bool stop_sublookup_iteration (return_t r) const
238 {
239 r.add_coverage (set);
240 return false;
241 }
242
243 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 {
268 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
281 inline void set_ignore_zwnj (bool ignore_zwnj_) { ignore_zwnj = ignore_zwnj_; }
282 inline void set_ignore_zwj (bool ignore_zwj_) { ignore_zwj = ignore_zwj_; }
283 inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
284 inline void set_mask (hb_mask_t mask_) { mask = mask_; }
285 inline void set_syllable (uint8_t syllable_) { syllable = syllable_; }
286 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
296 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
316 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_and_not_fvs (&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 {
342 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 }
354 inline void set_lookup_props (unsigned int lookup_props)
355 {
356 matcher.set_lookup_props (lookup_props);
357 }
358 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
366 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
375 inline void reject (void) { num_items++; match_glyph_data--; }
376
377 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 }
404 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
443 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>
446 inline return_t dispatch (const T &obj) { return obj.apply (this); }
447 static return_t default_return_value (void) { return false; }
448 bool stop_sublookup_iteration (return_t r) const { return r; }
449 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 const VariationStore &var_store;
473 skipping_iterator_t iter_input, iter_context;
474 unsigned int lookup_index;
475 unsigned int debug_depth;
476
477
478 hb_apply_context_t (unsigned int table_index_,
479 hb_font_t *font_,
480 hb_buffer_t *buffer_) :
481 table_index (table_index_),
482 font (font_), face (font->face), buffer (buffer_),
483 direction (buffer_->props.direction),
484 lookup_mask (1),
485 auto_zwj (true),
486 recurse_func (NULL),
487 nesting_level_left (HB_MAX_NESTING_LEVEL),
488 lookup_props (0),
489 gdef (*hb_ot_layout_from_face (face)->gdef),
490 has_glyph_classes (gdef.has_glyph_classes ()),
491 var_store (gdef.get_var_store ()),
492 iter_input (),
493 iter_context (),
494 lookup_index ((unsigned int) -1),
495 debug_depth (0) {}
496
497 inline void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; }
498 inline void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; }
499 inline void set_recurse_func (recurse_func_t func) { recurse_func = func; }
500 inline void set_lookup_index (unsigned int lookup_index_) { lookup_index = lookup_index_; }
501 inline void set_lookup_props (unsigned int lookup_props_)
502 {
503 lookup_props = lookup_props_;
504 iter_input.init (this, false);
505 iter_context.init (this, true);
506 }
507
508 inline bool
509 match_properties_mark (hb_codepoint_t glyph,
510 unsigned int glyph_props,
511 unsigned int match_props) const
512 {
513 /* If using mark filtering sets, the high short of
514 * match_props has the set index.
515 */
516 if (match_props & LookupFlag::UseMarkFilteringSet)
517 return gdef.mark_set_covers (match_props >> 16, glyph);
518
519 /* The second byte of match_props has the meaning
520 * "ignore marks of attachment type different than
521 * the attachment type specified."
522 */
523 if (match_props & LookupFlag::MarkAttachmentType)
524 return (match_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType);
525
526 return true;
527 }
528
529 inline bool
530 check_glyph_property (const hb_glyph_info_t *info,
531 unsigned int match_props) const
532 {
533 hb_codepoint_t glyph = info->codepoint;
534 unsigned int glyph_props = _hb_glyph_info_get_glyph_props (info);
535
536 /* Not covered, if, for example, glyph class is ligature and
537 * match_props includes LookupFlags::IgnoreLigatures
538 */
539 if (glyph_props & match_props & LookupFlag::IgnoreFlags)
540 return false;
541
542 if (unlikely (glyph_props & HB_OT_LAYOUT_GLYPH_PROPS_MARK))
543 return match_properties_mark (glyph, glyph_props, match_props);
544
545 return true;
546 }
547
548 inline void _set_glyph_props (hb_codepoint_t glyph_index,
549 unsigned int class_guess = 0,
550 bool ligature = false,
551 bool component = false) const
552 {
553 unsigned int add_in = _hb_glyph_info_get_glyph_props (&buffer->cur()) &
554 HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE;
555 add_in |= HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED;
556 if (ligature)
557 {
558 add_in |= HB_OT_LAYOUT_GLYPH_PROPS_LIGATED;
559 /* In the only place that the MULTIPLIED bit is used, Uniscribe
560 * seems to only care about the "last" transformation between
561 * Ligature and Multiple substitions. Ie. if you ligate, expand,
562 * and ligate again, it forgives the multiplication and acts as
563 * if only ligation happened. As such, clear MULTIPLIED bit.
564 */
565 add_in &= ~HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
566 }
567 if (component)
568 add_in |= HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED;
569 if (likely (has_glyph_classes))
570 _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | gdef.get_glyph_props (glyph_index));
571 else if (class_guess)
572 _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | class_guess);
573 }
574
575 inline void replace_glyph (hb_codepoint_t glyph_index) const
576 {
577 _set_glyph_props (glyph_index);
578 buffer->replace_glyph (glyph_index);
579 }
580 inline void replace_glyph_inplace (hb_codepoint_t glyph_index) const
581 {
582 _set_glyph_props (glyph_index);
583 buffer->cur().codepoint = glyph_index;
584 }
585 inline void replace_glyph_with_ligature (hb_codepoint_t glyph_index,
586 unsigned int class_guess) const
587 {
588 _set_glyph_props (glyph_index, class_guess, true);
589 buffer->replace_glyph (glyph_index);
590 }
591 inline void output_glyph_for_component (hb_codepoint_t glyph_index,
592 unsigned int class_guess) const
593 {
594 _set_glyph_props (glyph_index, class_guess, false, true);
595 buffer->output_glyph (glyph_index);
596 }
597 };
598
599
600
601 typedef bool (*intersects_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
602 typedef void (*collect_glyphs_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
603 typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
604
605 struct ContextClosureFuncs
606 {
607 intersects_func_t intersects;
608 };
609 struct ContextCollectGlyphsFuncs
610 {
611 collect_glyphs_func_t collect;
612 };
613 struct ContextApplyFuncs
614 {
615 match_func_t match;
616 };
617
618
619 static inline bool intersects_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
620 {
621 return glyphs->has (value);
622 }
623 static inline bool intersects_class (hb_set_t *glyphs, const USHORT &value, const void *data)
624 {
625 const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
626 return class_def.intersects_class (glyphs, value);
627 }
628 static inline bool intersects_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
629 {
630 const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
631 return (data+coverage).intersects (glyphs);
632 }
633
634 static inline bool intersects_array (hb_closure_context_t *c,
635 unsigned int count,
636 const USHORT values[],
637 intersects_func_t intersects_func,
638 const void *intersects_data)
639 {
640 for (unsigned int i = 0; i < count; i++)
641 if (likely (!intersects_func (c->glyphs, values[i], intersects_data)))
642 return false;
643 return true;
644 }
645
646
647 static inline void collect_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
648 {
649 glyphs->add (value);
650 }
651 static inline void collect_class (hb_set_t *glyphs, const USHORT &value, const void *data)
652 {
653 const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
654 class_def.add_class (glyphs, value);
655 }
656 static inline void collect_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
657 {
658 const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
659 (data+coverage).add_coverage (glyphs);
660 }
661 static inline void collect_array (hb_collect_glyphs_context_t *c HB_UNUSED,
662 hb_set_t *glyphs,
663 unsigned int count,
664 const USHORT values[],
665 collect_glyphs_func_t collect_func,
666 const void *collect_data)
667 {
668 for (unsigned int i = 0; i < count; i++)
669 collect_func (glyphs, values[i], collect_data);
670 }
671
672
673 static inline bool match_glyph (hb_codepoint_t glyph_id, const USHORT &value, const void *data HB_UNUSED)
674 {
675 return glyph_id == value;
676 }
677 static inline bool match_class (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
678 {
679 const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
680 return class_def.get_class (glyph_id) == value;
681 }
682 static inline bool match_coverage (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
683 {
684 const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
685 return (data+coverage).get_coverage (glyph_id) != NOT_COVERED;
686 }
687
688 static inline bool would_match_input (hb_would_apply_context_t *c,
689 unsigned int count, /* Including the first glyph (not matched) */
690 const USHORT input[], /* Array of input values--start with second glyph */
691 match_func_t match_func,
692 const void *match_data)
693 {
694 if (count != c->len)
695 return false;
696
697 for (unsigned int i = 1; i < count; i++)
698 if (likely (!match_func (c->glyphs[i], input[i - 1], match_data)))
699 return false;
700
701 return true;
702 }
703 static inline bool match_input (hb_apply_context_t *c,
704 unsigned int count, /* Including the first glyph (not matched) */
705 const USHORT input[], /* Array of input values--start with second glyph */
706 match_func_t match_func,
707 const void *match_data,
708 unsigned int *end_offset,
709 unsigned int match_positions[HB_MAX_CONTEXT_LENGTH],
710 bool *p_is_mark_ligature = NULL,
711 unsigned int *p_total_component_count = NULL)
712 {
713 TRACE_APPLY (NULL);
714
715 if (unlikely (count > HB_MAX_CONTEXT_LENGTH)) return_trace (false);
716
717 hb_buffer_t *buffer = c->buffer;
718
719 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
720 skippy_iter.reset (buffer->idx, count - 1);
721 skippy_iter.set_match_func (match_func, match_data, input);
722
723 /*
724 * This is perhaps the trickiest part of OpenType... Remarks:
725 *
726 * - If all components of the ligature were marks, we call this a mark ligature.
727 *
728 * - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize
729 * it as a ligature glyph.
730 *
731 * - Ligatures cannot be formed across glyphs attached to different components
732 * of previous ligatures. Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and
733 * LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother.
734 * However, it would be wrong to ligate that SHADDA,FATHA sequence.o
735 * There is an exception to this: If a ligature tries ligating with marks that
736 * belong to it itself, go ahead, assuming that the font designer knows what
737 * they are doing (otherwise it can break Indic stuff when a matra wants to
738 * ligate with a conjunct...)
739 */
740
741 bool is_mark_ligature = _hb_glyph_info_is_mark (&buffer->cur());
742
743 unsigned int total_component_count = 0;
744 total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->cur());
745
746 unsigned int first_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
747 unsigned int first_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
748
749 match_positions[0] = buffer->idx;
750 for (unsigned int i = 1; i < count; i++)
751 {
752 if (!skippy_iter.next ()) return_trace (false);
753
754 match_positions[i] = skippy_iter.idx;
755
756 unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx]);
757 unsigned int this_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]);
758
759 if (first_lig_id && first_lig_comp) {
760 /* If first component was attached to a previous ligature component,
761 * all subsequent components should be attached to the same ligature
762 * component, otherwise we shouldn't ligate them. */
763 if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp)
764 return_trace (false);
765 } else {
766 /* If first component was NOT attached to a previous ligature component,
767 * all subsequent components should also NOT be attached to any ligature
768 * component, unless they are attached to the first component itself! */
769 if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id))
770 return_trace (false);
771 }
772
773 is_mark_ligature = is_mark_ligature && _hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx]);
774 total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->info[skippy_iter.idx]);
775 }
776
777 *end_offset = skippy_iter.idx - buffer->idx + 1;
778
779 if (p_is_mark_ligature)
780 *p_is_mark_ligature = is_mark_ligature;
781
782 if (p_total_component_count)
783 *p_total_component_count = total_component_count;
784
785 return_trace (true);
786 }
787 static inline bool ligate_input (hb_apply_context_t *c,
788 unsigned int count, /* Including the first glyph */
789 unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */
790 unsigned int match_length,
791 hb_codepoint_t lig_glyph,
792 bool is_mark_ligature,
793 unsigned int total_component_count)
794 {
795 TRACE_APPLY (NULL);
796
797 hb_buffer_t *buffer = c->buffer;
798
799 buffer->merge_clusters (buffer->idx, buffer->idx + match_length);
800
801 /*
802 * - If it *is* a mark ligature, we don't allocate a new ligature id, and leave
803 * the ligature to keep its old ligature id. This will allow it to attach to
804 * a base ligature in GPOS. Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH,
805 * and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA wit a
806 * ligature id and component value of 2. Then if SHADDA,FATHA form a ligature
807 * later, we don't want them to lose their ligature id/component, otherwise
808 * GPOS will fail to correctly position the mark ligature on top of the
809 * LAM,LAM,HEH ligature. See:
810 * https://bugzilla.gnome.org/show_bug.cgi?id=676343
811 *
812 * - If a ligature is formed of components that some of which are also ligatures
813 * themselves, and those ligature components had marks attached to *their*
814 * components, we have to attach the marks to the new ligature component
815 * positions! Now *that*'s tricky! And these marks may be following the
816 * last component of the whole sequence, so we should loop forward looking
817 * for them and update them.
818 *
819 * Eg. the sequence is LAM,LAM,SHADDA,FATHA,HEH, and the font first forms a
820 * 'calt' ligature of LAM,HEH, leaving the SHADDA and FATHA with a ligature
821 * id and component == 1. Now, during 'liga', the LAM and the LAM-HEH ligature
822 * form a LAM-LAM-HEH ligature. We need to reassign the SHADDA and FATHA to
823 * the new ligature with a component value of 2.
824 *
825 * This in fact happened to a font... See:
826 * https://bugzilla.gnome.org/show_bug.cgi?id=437633
827 */
828
829 unsigned int klass = is_mark_ligature ? 0 : HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE;
830 unsigned int lig_id = is_mark_ligature ? 0 : _hb_allocate_lig_id (buffer);
831 unsigned int last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
832 unsigned int last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
833 unsigned int components_so_far = last_num_components;
834
835 if (!is_mark_ligature)
836 {
837 _hb_glyph_info_set_lig_props_for_ligature (&buffer->cur(), lig_id, total_component_count);
838 if (_hb_glyph_info_get_general_category (&buffer->cur()) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
839 {
840 _hb_glyph_info_set_general_category (&buffer->cur(), HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER);
841 }
842 }
843 c->replace_glyph_with_ligature (lig_glyph, klass);
844
845 for (unsigned int i = 1; i < count; i++)
846 {
847 while (buffer->idx < match_positions[i] && !buffer->in_error)
848 {
849 if (!is_mark_ligature) {
850 unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
851 if (this_comp == 0)
852 this_comp = last_num_components;
853 unsigned int new_lig_comp = components_so_far - last_num_components +
854 MIN (this_comp, last_num_components);
855 _hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp);
856 }
857 buffer->next_glyph ();
858 }
859
860 last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
861 last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
862 components_so_far += last_num_components;
863
864 /* Skip the base glyph */
865 buffer->idx++;
866 }
867
868 if (!is_mark_ligature && last_lig_id) {
869 /* Re-adjust components for any marks following. */
870 for (unsigned int i = buffer->idx; i < buffer->len; i++) {
871 if (last_lig_id == _hb_glyph_info_get_lig_id (&buffer->info[i])) {
872 unsigned int this_comp = _hb_glyph_info_get_lig_comp (&buffer->info[i]);
873 if (!this_comp)
874 break;
875 unsigned int new_lig_comp = components_so_far - last_num_components +
876 MIN (this_comp, last_num_components);
877 _hb_glyph_info_set_lig_props_for_mark (&buffer->info[i], lig_id, new_lig_comp);
878 } else
879 break;
880 }
881 }
882 return_trace (true);
883 }
884
885 static inline bool match_backtrack (hb_apply_context_t *c,
886 unsigned int count,
887 const USHORT backtrack[],
888 match_func_t match_func,
889 const void *match_data)
890 {
891 TRACE_APPLY (NULL);
892
893 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
894 skippy_iter.reset (c->buffer->backtrack_len (), count);
895 skippy_iter.set_match_func (match_func, match_data, backtrack);
896
897 for (unsigned int i = 0; i < count; i++)
898 if (!skippy_iter.prev ())
899 return_trace (false);
900
901 return_trace (true);
902 }
903
904 static inline bool match_lookahead (hb_apply_context_t *c,
905 unsigned int count,
906 const USHORT lookahead[],
907 match_func_t match_func,
908 const void *match_data,
909 unsigned int offset)
910 {
911 TRACE_APPLY (NULL);
912
913 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
914 skippy_iter.reset (c->buffer->idx + offset - 1, count);
915 skippy_iter.set_match_func (match_func, match_data, lookahead);
916
917 for (unsigned int i = 0; i < count; i++)
918 if (!skippy_iter.next ())
919 return_trace (false);
920
921 return_trace (true);
922 }
923
924
925
926 struct LookupRecord
927 {
928 inline bool sanitize (hb_sanitize_context_t *c) const
929 {
930 TRACE_SANITIZE (this);
931 return_trace (c->check_struct (this));
932 }
933
934 USHORT sequenceIndex; /* Index into current glyph
935 * sequence--first glyph = 0 */
936 USHORT lookupListIndex; /* Lookup to apply to that
937 * position--zero--based */
938 public:
939 DEFINE_SIZE_STATIC (4);
940 };
941
942
943 template <typename context_t>
944 static inline void recurse_lookups (context_t *c,
945 unsigned int lookupCount,
946 const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
947 {
948 for (unsigned int i = 0; i < lookupCount; i++)
949 c->recurse (lookupRecord[i].lookupListIndex);
950 }
951
952 static inline bool apply_lookup (hb_apply_context_t *c,
953 unsigned int count, /* Including the first glyph */
954 unsigned int match_positions[HB_MAX_CONTEXT_LENGTH], /* Including the first glyph */
955 unsigned int lookupCount,
956 const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */
957 unsigned int match_length)
958 {
959 TRACE_APPLY (NULL);
960
961 hb_buffer_t *buffer = c->buffer;
962 unsigned int end;
963
964 /* All positions are distance from beginning of *output* buffer.
965 * Adjust. */
966 {
967 unsigned int bl = buffer->backtrack_len ();
968 end = bl + match_length;
969
970 int delta = bl - buffer->idx;
971 /* Convert positions to new indexing. */
972 for (unsigned int j = 0; j < count; j++)
973 match_positions[j] += delta;
974 }
975
976 for (unsigned int i = 0; i < lookupCount && !buffer->in_error; i++)
977 {
978 unsigned int idx = lookupRecord[i].sequenceIndex;
979 if (idx >= count)
980 continue;
981
982 /* Don't recurse to ourself at same position.
983 * Note that this test is too naive, it doesn't catch longer loops. */
984 if (idx == 0 && lookupRecord[i].lookupListIndex == c->lookup_index)
985 continue;
986
987 buffer->move_to (match_positions[idx]);
988
989 unsigned int orig_len = buffer->backtrack_len () + buffer->lookahead_len ();
990 if (!c->recurse (lookupRecord[i].lookupListIndex))
991 continue;
992
993 unsigned int new_len = buffer->backtrack_len () + buffer->lookahead_len ();
994 int delta = new_len - orig_len;
995
996 if (!delta)
997 continue;
998
999 /* Recursed lookup changed buffer len. Adjust. */
1000
1001 end = int (end) + delta;
1002 if (end <= match_positions[idx])
1003 {
1004 /* End might end up being smaller than match_positions[idx] if the recursed
1005 * lookup ended up removing many items, more than we have had matched.
1006 * Just never rewind end back and get out of here.
1007 * https://bugs.chromium.org/p/chromium/issues/detail?id=659496 */
1008 end = match_positions[idx];
1009 /* There can't be any further changes. */
1010 break;
1011 }
1012
1013 unsigned int next = idx + 1; /* next now is the position after the recursed lookup. */
1014
1015 if (delta > 0)
1016 {
1017 if (unlikely (delta + count > HB_MAX_CONTEXT_LENGTH))
1018 break;
1019 }
1020 else
1021 {
1022 /* NOTE: delta is negative. */
1023 delta = MAX (delta, (int) next - (int) count);
1024 next -= delta;
1025 }
1026
1027 /* Shift! */
1028 memmove (match_positions + next + delta, match_positions + next,
1029 (count - next) * sizeof (match_positions[0]));
1030 next += delta;
1031 count += delta;
1032
1033 /* Fill in new entries. */
1034 for (unsigned int j = idx + 1; j < next; j++)
1035 match_positions[j] = match_positions[j - 1] + 1;
1036
1037 /* And fixup the rest. */
1038 for (; next < count; next++)
1039 match_positions[next] += delta;
1040 }
1041
1042 buffer->move_to (end);
1043
1044 return_trace (true);
1045 }
1046
1047
1048
1049 /* Contextual lookups */
1050
1051 struct ContextClosureLookupContext
1052 {
1053 ContextClosureFuncs funcs;
1054 const void *intersects_data;
1055 };
1056
1057 struct ContextCollectGlyphsLookupContext
1058 {
1059 ContextCollectGlyphsFuncs funcs;
1060 const void *collect_data;
1061 };
1062
1063 struct ContextApplyLookupContext
1064 {
1065 ContextApplyFuncs funcs;
1066 const void *match_data;
1067 };
1068
1069 static inline void context_closure_lookup (hb_closure_context_t *c,
1070 unsigned int inputCount, /* Including the first glyph (not matched) */
1071 const USHORT input[], /* Array of input values--start with second glyph */
1072 unsigned int lookupCount,
1073 const LookupRecord lookupRecord[],
1074 ContextClosureLookupContext &lookup_context)
1075 {
1076 if (intersects_array (c,
1077 inputCount ? inputCount - 1 : 0, input,
1078 lookup_context.funcs.intersects, lookup_context.intersects_data))
1079 recurse_lookups (c,
1080 lookupCount, lookupRecord);
1081 }
1082
1083 static inline void context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1084 unsigned int inputCount, /* Including the first glyph (not matched) */
1085 const USHORT input[], /* Array of input values--start with second glyph */
1086 unsigned int lookupCount,
1087 const LookupRecord lookupRecord[],
1088 ContextCollectGlyphsLookupContext &lookup_context)
1089 {
1090 collect_array (c, c->input,
1091 inputCount ? inputCount - 1 : 0, input,
1092 lookup_context.funcs.collect, lookup_context.collect_data);
1093 recurse_lookups (c,
1094 lookupCount, lookupRecord);
1095 }
1096
1097 static inline bool context_would_apply_lookup (hb_would_apply_context_t *c,
1098 unsigned int inputCount, /* Including the first glyph (not matched) */
1099 const USHORT input[], /* Array of input values--start with second glyph */
1100 unsigned int lookupCount HB_UNUSED,
1101 const LookupRecord lookupRecord[] HB_UNUSED,
1102 ContextApplyLookupContext &lookup_context)
1103 {
1104 return would_match_input (c,
1105 inputCount, input,
1106 lookup_context.funcs.match, lookup_context.match_data);
1107 }
1108 static inline bool context_apply_lookup (hb_apply_context_t *c,
1109 unsigned int inputCount, /* Including the first glyph (not matched) */
1110 const USHORT input[], /* Array of input values--start with second glyph */
1111 unsigned int lookupCount,
1112 const LookupRecord lookupRecord[],
1113 ContextApplyLookupContext &lookup_context)
1114 {
1115 unsigned int match_length = 0;
1116 unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
1117 return match_input (c,
1118 inputCount, input,
1119 lookup_context.funcs.match, lookup_context.match_data,
1120 &match_length, match_positions)
1121 && apply_lookup (c,
1122 inputCount, match_positions,
1123 lookupCount, lookupRecord,
1124 match_length);
1125 }
1126
1127 struct Rule
1128 {
1129 inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1130 {
1131 TRACE_CLOSURE (this);
1132 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1133 context_closure_lookup (c,
1134 inputCount, inputZ,
1135 lookupCount, lookupRecord,
1136 lookup_context);
1137 }
1138
1139 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1140 {
1141 TRACE_COLLECT_GLYPHS (this);
1142 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1143 context_collect_glyphs_lookup (c,
1144 inputCount, inputZ,
1145 lookupCount, lookupRecord,
1146 lookup_context);
1147 }
1148
1149 inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1150 {
1151 TRACE_WOULD_APPLY (this);
1152 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1153 return_trace (context_would_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1154 }
1155
1156 inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1157 {
1158 TRACE_APPLY (this);
1159 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1160 return_trace (context_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1161 }
1162
1163 public:
1164 inline bool sanitize (hb_sanitize_context_t *c) const
1165 {
1166 TRACE_SANITIZE (this);
1167 return inputCount.sanitize (c)
1168 && lookupCount.sanitize (c)
1169 && c->check_range (inputZ,
1170 inputZ[0].static_size * inputCount
1171 + lookupRecordX[0].static_size * lookupCount);
1172 }
1173
1174 protected:
1175 USHORT inputCount; /* Total number of glyphs in input
1176 * glyph sequence--includes the first
1177 * glyph */
1178 USHORT lookupCount; /* Number of LookupRecords */
1179 USHORT inputZ[VAR]; /* Array of match inputs--start with
1180 * second glyph */
1181 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in
1182 * design order */
1183 public:
1184 DEFINE_SIZE_ARRAY2 (4, inputZ, lookupRecordX);
1185 };
1186
1187 struct RuleSet
1188 {
1189 inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1190 {
1191 TRACE_CLOSURE (this);
1192 unsigned int num_rules = rule.len;
1193 for (unsigned int i = 0; i < num_rules; i++)
1194 (this+rule[i]).closure (c, lookup_context);
1195 }
1196
1197 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1198 {
1199 TRACE_COLLECT_GLYPHS (this);
1200 unsigned int num_rules = rule.len;
1201 for (unsigned int i = 0; i < num_rules; i++)
1202 (this+rule[i]).collect_glyphs (c, lookup_context);
1203 }
1204
1205 inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1206 {
1207 TRACE_WOULD_APPLY (this);
1208 unsigned int num_rules = rule.len;
1209 for (unsigned int i = 0; i < num_rules; i++)
1210 {
1211 if ((this+rule[i]).would_apply (c, lookup_context))
1212 return_trace (true);
1213 }
1214 return_trace (false);
1215 }
1216
1217 inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1218 {
1219 TRACE_APPLY (this);
1220 unsigned int num_rules = rule.len;
1221 for (unsigned int i = 0; i < num_rules; i++)
1222 {
1223 if ((this+rule[i]).apply (c, lookup_context))
1224 return_trace (true);
1225 }
1226 return_trace (false);
1227 }
1228
1229 inline bool sanitize (hb_sanitize_context_t *c) const
1230 {
1231 TRACE_SANITIZE (this);
1232 return_trace (rule.sanitize (c, this));
1233 }
1234
1235 protected:
1236 OffsetArrayOf<Rule>
1237 rule; /* Array of Rule tables
1238 * ordered by preference */
1239 public:
1240 DEFINE_SIZE_ARRAY (2, rule);
1241 };
1242
1243
1244 struct ContextFormat1
1245 {
1246 inline void closure (hb_closure_context_t *c) const
1247 {
1248 TRACE_CLOSURE (this);
1249
1250 const Coverage &cov = (this+coverage);
1251
1252 struct ContextClosureLookupContext lookup_context = {
1253 {intersects_glyph},
1254 NULL
1255 };
1256
1257 unsigned int count = ruleSet.len;
1258 for (unsigned int i = 0; i < count; i++)
1259 if (cov.intersects_coverage (c->glyphs, i)) {
1260 const RuleSet &rule_set = this+ruleSet[i];
1261 rule_set.closure (c, lookup_context);
1262 }
1263 }
1264
1265 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1266 {
1267 TRACE_COLLECT_GLYPHS (this);
1268 (this+coverage).add_coverage (c->input);
1269
1270 struct ContextCollectGlyphsLookupContext lookup_context = {
1271 {collect_glyph},
1272 NULL
1273 };
1274
1275 unsigned int count = ruleSet.len;
1276 for (unsigned int i = 0; i < count; i++)
1277 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1278 }
1279
1280 inline bool would_apply (hb_would_apply_context_t *c) const
1281 {
1282 TRACE_WOULD_APPLY (this);
1283
1284 const RuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1285 struct ContextApplyLookupContext lookup_context = {
1286 {match_glyph},
1287 NULL
1288 };
1289 return_trace (rule_set.would_apply (c, lookup_context));
1290 }
1291
1292 inline const Coverage &get_coverage (void) const
1293 {
1294 return this+coverage;
1295 }
1296
1297 inline bool apply (hb_apply_context_t *c) const
1298 {
1299 TRACE_APPLY (this);
1300 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1301 if (likely (index == NOT_COVERED))
1302 return_trace (false);
1303
1304 const RuleSet &rule_set = this+ruleSet[index];
1305 struct ContextApplyLookupContext lookup_context = {
1306 {match_glyph},
1307 NULL
1308 };
1309 return_trace (rule_set.apply (c, lookup_context));
1310 }
1311
1312 inline bool sanitize (hb_sanitize_context_t *c) const
1313 {
1314 TRACE_SANITIZE (this);
1315 return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1316 }
1317
1318 protected:
1319 USHORT format; /* Format identifier--format = 1 */
1320 OffsetTo<Coverage>
1321 coverage; /* Offset to Coverage table--from
1322 * beginning of table */
1323 OffsetArrayOf<RuleSet>
1324 ruleSet; /* Array of RuleSet tables
1325 * ordered by Coverage Index */
1326 public:
1327 DEFINE_SIZE_ARRAY (6, ruleSet);
1328 };
1329
1330
1331 struct ContextFormat2
1332 {
1333 inline void closure (hb_closure_context_t *c) const
1334 {
1335 TRACE_CLOSURE (this);
1336 if (!(this+coverage).intersects (c->glyphs))
1337 return;
1338
1339 const ClassDef &class_def = this+classDef;
1340
1341 struct ContextClosureLookupContext lookup_context = {
1342 {intersects_class},
1343 &class_def
1344 };
1345
1346 unsigned int count = ruleSet.len;
1347 for (unsigned int i = 0; i < count; i++)
1348 if (class_def.intersects_class (c->glyphs, i)) {
1349 const RuleSet &rule_set = this+ruleSet[i];
1350 rule_set.closure (c, lookup_context);
1351 }
1352 }
1353
1354 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1355 {
1356 TRACE_COLLECT_GLYPHS (this);
1357 (this+coverage).add_coverage (c->input);
1358
1359 const ClassDef &class_def = this+classDef;
1360 struct ContextCollectGlyphsLookupContext lookup_context = {
1361 {collect_class},
1362 &class_def
1363 };
1364
1365 unsigned int count = ruleSet.len;
1366 for (unsigned int i = 0; i < count; i++)
1367 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1368 }
1369
1370 inline bool would_apply (hb_would_apply_context_t *c) const
1371 {
1372 TRACE_WOULD_APPLY (this);
1373
1374 const ClassDef &class_def = this+classDef;
1375 unsigned int index = class_def.get_class (c->glyphs[0]);
1376 const RuleSet &rule_set = this+ruleSet[index];
1377 struct ContextApplyLookupContext lookup_context = {
1378 {match_class},
1379 &class_def
1380 };
1381 return_trace (rule_set.would_apply (c, lookup_context));
1382 }
1383
1384 inline const Coverage &get_coverage (void) const
1385 {
1386 return this+coverage;
1387 }
1388
1389 inline bool apply (hb_apply_context_t *c) const
1390 {
1391 TRACE_APPLY (this);
1392 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1393 if (likely (index == NOT_COVERED)) return_trace (false);
1394
1395 const ClassDef &class_def = this+classDef;
1396 index = class_def.get_class (c->buffer->cur().codepoint);
1397 const RuleSet &rule_set = this+ruleSet[index];
1398 struct ContextApplyLookupContext lookup_context = {
1399 {match_class},
1400 &class_def
1401 };
1402 return_trace (rule_set.apply (c, lookup_context));
1403 }
1404
1405 inline bool sanitize (hb_sanitize_context_t *c) const
1406 {
1407 TRACE_SANITIZE (this);
1408 return_trace (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this));
1409 }
1410
1411 protected:
1412 USHORT format; /* Format identifier--format = 2 */
1413 OffsetTo<Coverage>
1414 coverage; /* Offset to Coverage table--from
1415 * beginning of table */
1416 OffsetTo<ClassDef>
1417 classDef; /* Offset to glyph ClassDef table--from
1418 * beginning of table */
1419 OffsetArrayOf<RuleSet>
1420 ruleSet; /* Array of RuleSet tables
1421 * ordered by class */
1422 public:
1423 DEFINE_SIZE_ARRAY (8, ruleSet);
1424 };
1425
1426
1427 struct ContextFormat3
1428 {
1429 inline void closure (hb_closure_context_t *c) const
1430 {
1431 TRACE_CLOSURE (this);
1432 if (!(this+coverageZ[0]).intersects (c->glyphs))
1433 return;
1434
1435 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1436 struct ContextClosureLookupContext lookup_context = {
1437 {intersects_coverage},
1438 this
1439 };
1440 context_closure_lookup (c,
1441 glyphCount, (const USHORT *) (coverageZ + 1),
1442 lookupCount, lookupRecord,
1443 lookup_context);
1444 }
1445
1446 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1447 {
1448 TRACE_COLLECT_GLYPHS (this);
1449 (this+coverageZ[0]).add_coverage (c->input);
1450
1451 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1452 struct ContextCollectGlyphsLookupContext lookup_context = {
1453 {collect_coverage},
1454 this
1455 };
1456
1457 context_collect_glyphs_lookup (c,
1458 glyphCount, (const USHORT *) (coverageZ + 1),
1459 lookupCount, lookupRecord,
1460 lookup_context);
1461 }
1462
1463 inline bool would_apply (hb_would_apply_context_t *c) const
1464 {
1465 TRACE_WOULD_APPLY (this);
1466
1467 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1468 struct ContextApplyLookupContext lookup_context = {
1469 {match_coverage},
1470 this
1471 };
1472 return_trace (context_would_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1473 }
1474
1475 inline const Coverage &get_coverage (void) const
1476 {
1477 return this+coverageZ[0];
1478 }
1479
1480 inline bool apply (hb_apply_context_t *c) const
1481 {
1482 TRACE_APPLY (this);
1483 unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint);
1484 if (likely (index == NOT_COVERED)) return_trace (false);
1485
1486 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1487 struct ContextApplyLookupContext lookup_context = {
1488 {match_coverage},
1489 this
1490 };
1491 return_trace (context_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1492 }
1493
1494 inline bool sanitize (hb_sanitize_context_t *c) const
1495 {
1496 TRACE_SANITIZE (this);
1497 if (!c->check_struct (this)) return_trace (false);
1498 unsigned int count = glyphCount;
1499 if (!count) return_trace (false); /* We want to access coverageZ[0] freely. */
1500 if (!c->check_array (coverageZ, coverageZ[0].static_size, count)) return_trace (false);
1501 for (unsigned int i = 0; i < count; i++)
1502 if (!coverageZ[i].sanitize (c, this)) return_trace (false);
1503 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * count);
1504 return_trace (c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount));
1505 }
1506
1507 protected:
1508 USHORT format; /* Format identifier--format = 3 */
1509 USHORT glyphCount; /* Number of glyphs in the input glyph
1510 * sequence */
1511 USHORT lookupCount; /* Number of LookupRecords */
1512 OffsetTo<Coverage>
1513 coverageZ[VAR]; /* Array of offsets to Coverage
1514 * table in glyph sequence order */
1515 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in
1516 * design order */
1517 public:
1518 DEFINE_SIZE_ARRAY2 (6, coverageZ, lookupRecordX);
1519 };
1520
1521 struct Context
1522 {
1523 template <typename context_t>
1524 inline typename context_t::return_t dispatch (context_t *c) const
1525 {
1526 TRACE_DISPATCH (this, u.format);
1527 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1528 switch (u.format) {
1529 case 1: return_trace (c->dispatch (u.format1));
1530 case 2: return_trace (c->dispatch (u.format2));
1531 case 3: return_trace (c->dispatch (u.format3));
1532 default:return_trace (c->default_return_value ());
1533 }
1534 }
1535
1536 protected:
1537 union {
1538 USHORT format; /* Format identifier */
1539 ContextFormat1 format1;
1540 ContextFormat2 format2;
1541 ContextFormat3 format3;
1542 } u;
1543 };
1544
1545
1546 /* Chaining Contextual lookups */
1547
1548 struct ChainContextClosureLookupContext
1549 {
1550 ContextClosureFuncs funcs;
1551 const void *intersects_data[3];
1552 };
1553
1554 struct ChainContextCollectGlyphsLookupContext
1555 {
1556 ContextCollectGlyphsFuncs funcs;
1557 const void *collect_data[3];
1558 };
1559
1560 struct ChainContextApplyLookupContext
1561 {
1562 ContextApplyFuncs funcs;
1563 const void *match_data[3];
1564 };
1565
1566 static inline void chain_context_closure_lookup (hb_closure_context_t *c,
1567 unsigned int backtrackCount,
1568 const USHORT backtrack[],
1569 unsigned int inputCount, /* Including the first glyph (not matched) */
1570 const USHORT input[], /* Array of input values--start with second glyph */
1571 unsigned int lookaheadCount,
1572 const USHORT lookahead[],
1573 unsigned int lookupCount,
1574 const LookupRecord lookupRecord[],
1575 ChainContextClosureLookupContext &lookup_context)
1576 {
1577 if (intersects_array (c,
1578 backtrackCount, backtrack,
1579 lookup_context.funcs.intersects, lookup_context.intersects_data[0])
1580 && intersects_array (c,
1581 inputCount ? inputCount - 1 : 0, input,
1582 lookup_context.funcs.intersects, lookup_context.intersects_data[1])
1583 && intersects_array (c,
1584 lookaheadCount, lookahead,
1585 lookup_context.funcs.intersects, lookup_context.intersects_data[2]))
1586 recurse_lookups (c,
1587 lookupCount, lookupRecord);
1588 }
1589
1590 static inline void chain_context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1591 unsigned int backtrackCount,
1592 const USHORT backtrack[],
1593 unsigned int inputCount, /* Including the first glyph (not matched) */
1594 const USHORT input[], /* Array of input values--start with second glyph */
1595 unsigned int lookaheadCount,
1596 const USHORT lookahead[],
1597 unsigned int lookupCount,
1598 const LookupRecord lookupRecord[],
1599 ChainContextCollectGlyphsLookupContext &lookup_context)
1600 {
1601 collect_array (c, c->before,
1602 backtrackCount, backtrack,
1603 lookup_context.funcs.collect, lookup_context.collect_data[0]);
1604 collect_array (c, c->input,
1605 inputCount ? inputCount - 1 : 0, input,
1606 lookup_context.funcs.collect, lookup_context.collect_data[1]);
1607 collect_array (c, c->after,
1608 lookaheadCount, lookahead,
1609 lookup_context.funcs.collect, lookup_context.collect_data[2]);
1610 recurse_lookups (c,
1611 lookupCount, lookupRecord);
1612 }
1613
1614 static inline bool chain_context_would_apply_lookup (hb_would_apply_context_t *c,
1615 unsigned int backtrackCount,
1616 const USHORT backtrack[] HB_UNUSED,
1617 unsigned int inputCount, /* Including the first glyph (not matched) */
1618 const USHORT input[], /* Array of input values--start with second glyph */
1619 unsigned int lookaheadCount,
1620 const USHORT lookahead[] HB_UNUSED,
1621 unsigned int lookupCount HB_UNUSED,
1622 const LookupRecord lookupRecord[] HB_UNUSED,
1623 ChainContextApplyLookupContext &lookup_context)
1624 {
1625 return (c->zero_context ? !backtrackCount && !lookaheadCount : true)
1626 && would_match_input (c,
1627 inputCount, input,
1628 lookup_context.funcs.match, lookup_context.match_data[1]);
1629 }
1630
1631 static inline bool chain_context_apply_lookup (hb_apply_context_t *c,
1632 unsigned int backtrackCount,
1633 const USHORT backtrack[],
1634 unsigned int inputCount, /* Including the first glyph (not matched) */
1635 const USHORT input[], /* Array of input values--start with second glyph */
1636 unsigned int lookaheadCount,
1637 const USHORT lookahead[],
1638 unsigned int lookupCount,
1639 const LookupRecord lookupRecord[],
1640 ChainContextApplyLookupContext &lookup_context)
1641 {
1642 unsigned int match_length = 0;
1643 unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
1644 return match_input (c,
1645 inputCount, input,
1646 lookup_context.funcs.match, lookup_context.match_data[1],
1647 &match_length, match_positions)
1648 && match_backtrack (c,
1649 backtrackCount, backtrack,
1650 lookup_context.funcs.match, lookup_context.match_data[0])
1651 && match_lookahead (c,
1652 lookaheadCount, lookahead,
1653 lookup_context.funcs.match, lookup_context.match_data[2],
1654 match_length)
1655 && apply_lookup (c,
1656 inputCount, match_positions,
1657 lookupCount, lookupRecord,
1658 match_length);
1659 }
1660
1661 struct ChainRule
1662 {
1663 inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1664 {
1665 TRACE_CLOSURE (this);
1666 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1667 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1668 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1669 chain_context_closure_lookup (c,
1670 backtrack.len, backtrack.array,
1671 input.len, input.array,
1672 lookahead.len, lookahead.array,
1673 lookup.len, lookup.array,
1674 lookup_context);
1675 }
1676
1677 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1678 {
1679 TRACE_COLLECT_GLYPHS (this);
1680 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1681 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1682 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1683 chain_context_collect_glyphs_lookup (c,
1684 backtrack.len, backtrack.array,
1685 input.len, input.array,
1686 lookahead.len, lookahead.array,
1687 lookup.len, lookup.array,
1688 lookup_context);
1689 }
1690
1691 inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1692 {
1693 TRACE_WOULD_APPLY (this);
1694 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1695 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1696 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1697 return_trace (chain_context_would_apply_lookup (c,
1698 backtrack.len, backtrack.array,
1699 input.len, input.array,
1700 lookahead.len, lookahead.array, lookup.len,
1701 lookup.array, lookup_context));
1702 }
1703
1704 inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1705 {
1706 TRACE_APPLY (this);
1707 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1708 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1709 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1710 return_trace (chain_context_apply_lookup (c,
1711 backtrack.len, backtrack.array,
1712 input.len, input.array,
1713 lookahead.len, lookahead.array, lookup.len,
1714 lookup.array, lookup_context));
1715 }
1716
1717 inline bool sanitize (hb_sanitize_context_t *c) const
1718 {
1719 TRACE_SANITIZE (this);
1720 if (!backtrack.sanitize (c)) return_trace (false);
1721 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1722 if (!input.sanitize (c)) return_trace (false);
1723 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1724 if (!lookahead.sanitize (c)) return_trace (false);
1725 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1726 return_trace (lookup.sanitize (c));
1727 }
1728
1729 protected:
1730 ArrayOf<USHORT>
1731 backtrack; /* Array of backtracking values
1732 * (to be matched before the input
1733 * sequence) */
1734 HeadlessArrayOf<USHORT>
1735 inputX; /* Array of input values (start with
1736 * second glyph) */
1737 ArrayOf<USHORT>
1738 lookaheadX; /* Array of lookahead values's (to be
1739 * matched after the input sequence) */
1740 ArrayOf<LookupRecord>
1741 lookupX; /* Array of LookupRecords--in
1742 * design order) */
1743 public:
1744 DEFINE_SIZE_MIN (8);
1745 };
1746
1747 struct ChainRuleSet
1748 {
1749 inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1750 {
1751 TRACE_CLOSURE (this);
1752 unsigned int num_rules = rule.len;
1753 for (unsigned int i = 0; i < num_rules; i++)
1754 (this+rule[i]).closure (c, lookup_context);
1755 }
1756
1757 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1758 {
1759 TRACE_COLLECT_GLYPHS (this);
1760 unsigned int num_rules = rule.len;
1761 for (unsigned int i = 0; i < num_rules; i++)
1762 (this+rule[i]).collect_glyphs (c, lookup_context);
1763 }
1764
1765 inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1766 {
1767 TRACE_WOULD_APPLY (this);
1768 unsigned int num_rules = rule.len;
1769 for (unsigned int i = 0; i < num_rules; i++)
1770 if ((this+rule[i]).would_apply (c, lookup_context))
1771 return_trace (true);
1772
1773 return_trace (false);
1774 }
1775
1776 inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1777 {
1778 TRACE_APPLY (this);
1779 unsigned int num_rules = rule.len;
1780 for (unsigned int i = 0; i < num_rules; i++)
1781 if ((this+rule[i]).apply (c, lookup_context))
1782 return_trace (true);
1783
1784 return_trace (false);
1785 }
1786
1787 inline bool sanitize (hb_sanitize_context_t *c) const
1788 {
1789 TRACE_SANITIZE (this);
1790 return_trace (rule.sanitize (c, this));
1791 }
1792
1793 protected:
1794 OffsetArrayOf<ChainRule>
1795 rule; /* Array of ChainRule tables
1796 * ordered by preference */
1797 public:
1798 DEFINE_SIZE_ARRAY (2, rule);
1799 };
1800
1801 struct ChainContextFormat1
1802 {
1803 inline void closure (hb_closure_context_t *c) const
1804 {
1805 TRACE_CLOSURE (this);
1806 const Coverage &cov = (this+coverage);
1807
1808 struct ChainContextClosureLookupContext lookup_context = {
1809 {intersects_glyph},
1810 {NULL, NULL, NULL}
1811 };
1812
1813 unsigned int count = ruleSet.len;
1814 for (unsigned int i = 0; i < count; i++)
1815 if (cov.intersects_coverage (c->glyphs, i)) {
1816 const ChainRuleSet &rule_set = this+ruleSet[i];
1817 rule_set.closure (c, lookup_context);
1818 }
1819 }
1820
1821 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1822 {
1823 TRACE_COLLECT_GLYPHS (this);
1824 (this+coverage).add_coverage (c->input);
1825
1826 struct ChainContextCollectGlyphsLookupContext lookup_context = {
1827 {collect_glyph},
1828 {NULL, NULL, NULL}
1829 };
1830
1831 unsigned int count = ruleSet.len;
1832 for (unsigned int i = 0; i < count; i++)
1833 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1834 }
1835
1836 inline bool would_apply (hb_would_apply_context_t *c) const
1837 {
1838 TRACE_WOULD_APPLY (this);
1839
1840 const ChainRuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1841 struct ChainContextApplyLookupContext lookup_context = {
1842 {match_glyph},
1843 {NULL, NULL, NULL}
1844 };
1845 return_trace (rule_set.would_apply (c, lookup_context));
1846 }
1847
1848 inline const Coverage &get_coverage (void) const
1849 {
1850 return this+coverage;
1851 }
1852
1853 inline bool apply (hb_apply_context_t *c) const
1854 {
1855 TRACE_APPLY (this);
1856 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1857 if (likely (index == NOT_COVERED)) return_trace (false);
1858
1859 const ChainRuleSet &rule_set = this+ruleSet[index];
1860 struct ChainContextApplyLookupContext lookup_context = {
1861 {match_glyph},
1862 {NULL, NULL, NULL}
1863 };
1864 return_trace (rule_set.apply (c, lookup_context));
1865 }
1866
1867 inline bool sanitize (hb_sanitize_context_t *c) const
1868 {
1869 TRACE_SANITIZE (this);
1870 return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1871 }
1872
1873 protected:
1874 USHORT format; /* Format identifier--format = 1 */
1875 OffsetTo<Coverage>
1876 coverage; /* Offset to Coverage table--from
1877 * beginning of table */
1878 OffsetArrayOf<ChainRuleSet>
1879 ruleSet; /* Array of ChainRuleSet tables
1880 * ordered by Coverage Index */
1881 public:
1882 DEFINE_SIZE_ARRAY (6, ruleSet);
1883 };
1884
1885 struct ChainContextFormat2
1886 {
1887 inline void closure (hb_closure_context_t *c) const
1888 {
1889 TRACE_CLOSURE (this);
1890 if (!(this+coverage).intersects (c->glyphs))
1891 return;
1892
1893 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1894 const ClassDef &input_class_def = this+inputClassDef;
1895 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1896
1897 struct ChainContextClosureLookupContext lookup_context = {
1898 {intersects_class},
1899 {&backtrack_class_def,
1900 &input_class_def,
1901 &lookahead_class_def}
1902 };
1903
1904 unsigned int count = ruleSet.len;
1905 for (unsigned int i = 0; i < count; i++)
1906 if (input_class_def.intersects_class (c->glyphs, i)) {
1907 const ChainRuleSet &rule_set = this+ruleSet[i];
1908 rule_set.closure (c, lookup_context);
1909 }
1910 }
1911
1912 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1913 {
1914 TRACE_COLLECT_GLYPHS (this);
1915 (this+coverage).add_coverage (c->input);
1916
1917 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1918 const ClassDef &input_class_def = this+inputClassDef;
1919 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1920
1921 struct ChainContextCollectGlyphsLookupContext lookup_context = {
1922 {collect_class},
1923 {&backtrack_class_def,
1924 &input_class_def,
1925 &lookahead_class_def}
1926 };
1927
1928 unsigned int count = ruleSet.len;
1929 for (unsigned int i = 0; i < count; i++)
1930 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1931 }
1932
1933 inline bool would_apply (hb_would_apply_context_t *c) const
1934 {
1935 TRACE_WOULD_APPLY (this);
1936
1937 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1938 const ClassDef &input_class_def = this+inputClassDef;
1939 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1940
1941 unsigned int index = input_class_def.get_class (c->glyphs[0]);
1942 const ChainRuleSet &rule_set = this+ruleSet[index];
1943 struct ChainContextApplyLookupContext lookup_context = {
1944 {match_class},
1945 {&backtrack_class_def,
1946 &input_class_def,
1947 &lookahead_class_def}
1948 };
1949 return_trace (rule_set.would_apply (c, lookup_context));
1950 }
1951
1952 inline const Coverage &get_coverage (void) const
1953 {
1954 return this+coverage;
1955 }
1956
1957 inline bool apply (hb_apply_context_t *c) const
1958 {
1959 TRACE_APPLY (this);
1960 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1961 if (likely (index == NOT_COVERED)) return_trace (false);
1962
1963 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1964 const ClassDef &input_class_def = this+inputClassDef;
1965 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1966
1967 index = input_class_def.get_class (c->buffer->cur().codepoint);
1968 const ChainRuleSet &rule_set = this+ruleSet[index];
1969 struct ChainContextApplyLookupContext lookup_context = {
1970 {match_class},
1971 {&backtrack_class_def,
1972 &input_class_def,
1973 &lookahead_class_def}
1974 };
1975 return_trace (rule_set.apply (c, lookup_context));
1976 }
1977
1978 inline bool sanitize (hb_sanitize_context_t *c) const
1979 {
1980 TRACE_SANITIZE (this);
1981 return_trace (coverage.sanitize (c, this) &&
1982 backtrackClassDef.sanitize (c, this) &&
1983 inputClassDef.sanitize (c, this) &&
1984 lookaheadClassDef.sanitize (c, this) &&
1985 ruleSet.sanitize (c, this));
1986 }
1987
1988 protected:
1989 USHORT format; /* Format identifier--format = 2 */
1990 OffsetTo<Coverage>
1991 coverage; /* Offset to Coverage table--from
1992 * beginning of table */
1993 OffsetTo<ClassDef>
1994 backtrackClassDef; /* Offset to glyph ClassDef table
1995 * containing backtrack sequence
1996 * data--from beginning of table */
1997 OffsetTo<ClassDef>
1998 inputClassDef; /* Offset to glyph ClassDef
1999 * table containing input sequence
2000 * data--from beginning of table */
2001 OffsetTo<ClassDef>
2002 lookaheadClassDef; /* Offset to glyph ClassDef table
2003 * containing lookahead sequence
2004 * data--from beginning of table */
2005 OffsetArrayOf<ChainRuleSet>
2006 ruleSet; /* Array of ChainRuleSet tables
2007 * ordered by class */
2008 public:
2009 DEFINE_SIZE_ARRAY (12, ruleSet);
2010 };
2011
2012 struct ChainContextFormat3
2013 {
2014 inline void closure (hb_closure_context_t *c) const
2015 {
2016 TRACE_CLOSURE (this);
2017 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2018
2019 if (!(this+input[0]).intersects (c->glyphs))
2020 return;
2021
2022 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2023 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2024 struct ChainContextClosureLookupContext lookup_context = {
2025 {intersects_coverage},
2026 {this, this, this}
2027 };
2028 chain_context_closure_lookup (c,
2029 backtrack.len, (const USHORT *) backtrack.array,
2030 input.len, (const USHORT *) input.array + 1,
2031 lookahead.len, (const USHORT *) lookahead.array,
2032 lookup.len, lookup.array,
2033 lookup_context);
2034 }
2035
2036 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
2037 {
2038 TRACE_COLLECT_GLYPHS (this);
2039 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2040
2041 (this+input[0]).add_coverage (c->input);
2042
2043 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2044 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2045 struct ChainContextCollectGlyphsLookupContext lookup_context = {
2046 {collect_coverage},
2047 {this, this, this}
2048 };
2049 chain_context_collect_glyphs_lookup (c,
2050 backtrack.len, (const USHORT *) backtrack.array,
2051 input.len, (const USHORT *) input.array + 1,
2052 lookahead.len, (const USHORT *) lookahead.array,
2053 lookup.len, lookup.array,
2054 lookup_context);
2055 }
2056
2057 inline bool would_apply (hb_would_apply_context_t *c) const
2058 {
2059 TRACE_WOULD_APPLY (this);
2060
2061 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2062 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2063 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2064 struct ChainContextApplyLookupContext lookup_context = {
2065 {match_coverage},
2066 {this, this, this}
2067 };
2068 return_trace (chain_context_would_apply_lookup (c,
2069 backtrack.len, (const USHORT *) backtrack.array,
2070 input.len, (const USHORT *) input.array + 1,
2071 lookahead.len, (const USHORT *) lookahead.array,
2072 lookup.len, lookup.array, lookup_context));
2073 }
2074
2075 inline const Coverage &get_coverage (void) const
2076 {
2077 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2078 return this+input[0];
2079 }
2080
2081 inline bool apply (hb_apply_context_t *c) const
2082 {
2083 TRACE_APPLY (this);
2084 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2085
2086 unsigned int index = (this+input[0]).get_coverage (c->buffer->cur().codepoint);
2087 if (likely (index == NOT_COVERED)) return_trace (false);
2088
2089 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2090 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2091 struct ChainContextApplyLookupContext lookup_context = {
2092 {match_coverage},
2093 {this, this, this}
2094 };
2095 return_trace (chain_context_apply_lookup (c,
2096 backtrack.len, (const USHORT *) backtrack.array,
2097 input.len, (const USHORT *) input.array + 1,
2098 lookahead.len, (const USHORT *) lookahead.array,
2099 lookup.len, lookup.array, lookup_context));
2100 }
2101
2102 inline bool sanitize (hb_sanitize_context_t *c) const
2103 {
2104 TRACE_SANITIZE (this);
2105 if (!backtrack.sanitize (c, this)) return_trace (false);
2106 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2107 if (!input.sanitize (c, this)) return_trace (false);
2108 if (!input.len) return_trace (false); /* To be consistent with Context. */
2109 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2110 if (!lookahead.sanitize (c, this)) return_trace (false);
2111 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2112 return_trace (lookup.sanitize (c));
2113 }
2114
2115 protected:
2116 USHORT format; /* Format identifier--format = 3 */
2117 OffsetArrayOf<Coverage>
2118 backtrack; /* Array of coverage tables
2119 * in backtracking sequence, in glyph
2120 * sequence order */
2121 OffsetArrayOf<Coverage>
2122 inputX ; /* Array of coverage
2123 * tables in input sequence, in glyph
2124 * sequence order */
2125 OffsetArrayOf<Coverage>
2126 lookaheadX; /* Array of coverage tables
2127 * in lookahead sequence, in glyph
2128 * sequence order */
2129 ArrayOf<LookupRecord>
2130 lookupX; /* Array of LookupRecords--in
2131 * design order) */
2132 public:
2133 DEFINE_SIZE_MIN (10);
2134 };
2135
2136 struct ChainContext
2137 {
2138 template <typename context_t>
2139 inline typename context_t::return_t dispatch (context_t *c) const
2140 {
2141 TRACE_DISPATCH (this, u.format);
2142 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
2143 switch (u.format) {
2144 case 1: return_trace (c->dispatch (u.format1));
2145 case 2: return_trace (c->dispatch (u.format2));
2146 case 3: return_trace (c->dispatch (u.format3));
2147 default:return_trace (c->default_return_value ());
2148 }
2149 }
2150
2151 protected:
2152 union {
2153 USHORT format; /* Format identifier */
2154 ChainContextFormat1 format1;
2155 ChainContextFormat2 format2;
2156 ChainContextFormat3 format3;
2157 } u;
2158 };
2159
2160
2161 template <typename T>
2162 struct ExtensionFormat1
2163 {
2164 inline unsigned int get_type (void) const { return extensionLookupType; }
2165
2166 template <typename X>
2167 inline const X& get_subtable (void) const
2168 {
2169 unsigned int offset = extensionOffset;
2170 if (unlikely (!offset)) return Null(typename T::LookupSubTable);
2171 return StructAtOffset<typename T::LookupSubTable> (this, offset);
2172 }
2173
2174 template <typename context_t>
2175 inline typename context_t::return_t dispatch (context_t *c) const
2176 {
2177 TRACE_DISPATCH (this, format);
2178 if (unlikely (!c->may_dispatch (this, this))) return_trace (c->no_dispatch_return_value ());
2179 return_trace (get_subtable<typename T::LookupSubTable> ().dispatch (c, get_type ()));
2180 }
2181
2182 /* This is called from may_dispatch() above with hb_sanitize_context_t. */
2183 inline bool sanitize (hb_sanitize_context_t *c) const
2184 {
2185 TRACE_SANITIZE (this);
2186 return_trace (c->check_struct (this) && extensionOffset != 0);
2187 }
2188
2189 protected:
2190 USHORT format; /* Format identifier. Set to 1. */
2191 USHORT extensionLookupType; /* Lookup type of subtable referenced
2192 * by ExtensionOffset (i.e. the
2193 * extension subtable). */
2194 ULONG extensionOffset; /* Offset to the extension subtable,
2195 * of lookup type subtable. */
2196 public:
2197 DEFINE_SIZE_STATIC (8);
2198 };
2199
2200 template <typename T>
2201 struct Extension
2202 {
2203 inline unsigned int get_type (void) const
2204 {
2205 switch (u.format) {
2206 case 1: return u.format1.get_type ();
2207 default:return 0;
2208 }
2209 }
2210 template <typename X>
2211 inline const X& get_subtable (void) const
2212 {
2213 switch (u.format) {
2214 case 1: return u.format1.template get_subtable<typename T::LookupSubTable> ();
2215 default:return Null(typename T::LookupSubTable);
2216 }
2217 }
2218
2219 template <typename context_t>
2220 inline typename context_t::return_t dispatch (context_t *c) const
2221 {
2222 TRACE_DISPATCH (this, u.format);
2223 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
2224 switch (u.format) {
2225 case 1: return_trace (u.format1.dispatch (c));
2226 default:return_trace (c->default_return_value ());
2227 }
2228 }
2229
2230 protected:
2231 union {
2232 USHORT format; /* Format identifier */
2233 ExtensionFormat1<T> format1;
2234 } u;
2235 };
2236
2237
2238 /*
2239 * GSUB/GPOS Common
2240 */
2241
2242 struct GSUBGPOS
2243 {
2244 static const hb_tag_t GSUBTag = HB_OT_TAG_GSUB;
2245 static const hb_tag_t GPOSTag = HB_OT_TAG_GPOS;
2246
2247 inline unsigned int get_script_count (void) const
2248 { return (this+scriptList).len; }
2249 inline const Tag& get_script_tag (unsigned int i) const
2250 { return (this+scriptList).get_tag (i); }
2251 inline unsigned int get_script_tags (unsigned int start_offset,
2252 unsigned int *script_count /* IN/OUT */,
2253 hb_tag_t *script_tags /* OUT */) const
2254 { return (this+scriptList).get_tags (start_offset, script_count, script_tags); }
2255 inline const Script& get_script (unsigned int i) const
2256 { return (this+scriptList)[i]; }
2257 inline bool find_script_index (hb_tag_t tag, unsigned int *index) const
2258 { return (this+scriptList).find_index (tag, index); }
2259
2260 inline unsigned int get_feature_count (void) const
2261 { return (this+featureList).len; }
2262 inline hb_tag_t get_feature_tag (unsigned int i) const
2263 { return i == Index::NOT_FOUND_INDEX ? HB_TAG_NONE : (this+featureList).get_tag (i); }
2264 inline unsigned int get_feature_tags (unsigned int start_offset,
2265 unsigned int *feature_count /* IN/OUT */,
2266 hb_tag_t *feature_tags /* OUT */) const
2267 { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); }
2268 inline const Feature& get_feature (unsigned int i) const
2269 { return (this+featureList)[i]; }
2270 inline bool find_feature_index (hb_tag_t tag, unsigned int *index) const
2271 { return (this+featureList).find_index (tag, index); }
2272
2273 inline unsigned int get_lookup_count (void) const
2274 { return (this+lookupList).len; }
2275 inline const Lookup& get_lookup (unsigned int i) const
2276 { return (this+lookupList)[i]; }
2277
2278 inline bool find_variations_index (const int *coords, unsigned int num_coords,
2279 unsigned int *index) const
2280 { return (version.to_int () >= 0x00010001u ? this+featureVars : Null(FeatureVariations))
2281 .find_index (coords, num_coords, index); }
2282 inline const Feature& get_feature_variation (unsigned int feature_index,
2283 unsigned int variations_index) const
2284 {
2285 if (FeatureVariations::NOT_FOUND_INDEX != variations_index &&
2286 version.to_int () >= 0x00010001u)
2287 {
2288 const Feature *feature = (this+featureVars).find_substitute (variations_index,
2289 feature_index);
2290 if (feature)
2291 return *feature;
2292 }
2293 return get_feature (feature_index);
2294 }
2295
2296 inline bool sanitize (hb_sanitize_context_t *c) const
2297 {
2298 TRACE_SANITIZE (this);
2299 return_trace (version.sanitize (c) &&
2300 likely (version.major == 1) &&
2301 scriptList.sanitize (c, this) &&
2302 featureList.sanitize (c, this) &&
2303 lookupList.sanitize (c, this) &&
2304 (version.to_int () < 0x00010001u || featureVars.sanitize (c, this)));
2305 }
2306
2307 protected:
2308 FixedVersion<>version; /* Version of the GSUB/GPOS table--initially set
2309 * to 0x00010000u */
2310 OffsetTo<ScriptList>
2311 scriptList; /* ScriptList table */
2312 OffsetTo<FeatureList>
2313 featureList; /* FeatureList table */
2314 OffsetTo<LookupList>
2315 lookupList; /* LookupList table */
2316 OffsetTo<FeatureVariations, ULONG>
2317 featureVars; /* Offset to Feature Variations
2318 table--from beginning of table
2319 * (may be NULL). Introduced
2320 * in version 0x00010001. */
2321 public:
2322 DEFINE_SIZE_MIN (10);
2323 };
2324
2325
2326 } /* namespace OT */
2327
2328
2329 #endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */