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_ = 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_ = 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 (&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 skipping_iterator_t iter_input, iter_context;
473 unsigned int lookup_index;
474 unsigned int debug_depth;
475
476
477 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 (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
495 inline void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; }
496 inline void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; }
497 inline void set_recurse_func (recurse_func_t func) { recurse_func = func; }
498 inline void set_lookup_index (unsigned int lookup_index_) { lookup_index = lookup_index_; }
499 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
507 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
528 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
546 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
573 inline void replace_glyph (hb_codepoint_t glyph_index) const
574 {
575 _set_glyph_props (glyph_index);
576 buffer->replace_glyph (glyph_index);
577 }
578 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 }
583 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 }
589 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
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 }
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 }
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
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
645 static inline void collect_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
646 {
647 glyphs->add (value);
648 }
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 }
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 }
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
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 }
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 }
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
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 }
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[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 > 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 }
785 static inline bool ligate_input (hb_apply_context_t *c,
786 unsigned int count, /* Including the first glyph */
787 unsigned int match_positions[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 _hb_glyph_info_set_modified_combining_class (&buffer->cur(), 0);
840 }
841 }
842 c->replace_glyph_with_ligature (lig_glyph, klass);
843
844 for (unsigned int i = 1; i < count; i++)
845 {
846 while (buffer->idx < match_positions[i])
847 {
848 if (!is_mark_ligature) {
849 unsigned int new_lig_comp = components_so_far - last_num_components +
850 MIN (MAX (_hb_glyph_info_get_lig_comp (&buffer->cur()), 1u), last_num_components);
851 _hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp);
852 }
853 buffer->next_glyph ();
854 }
855
856 last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
857 last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
858 components_so_far += last_num_components;
859
860 /* Skip the base glyph */
861 buffer->idx++;
862 }
863
864 if (!is_mark_ligature && last_lig_id) {
865 /* Re-adjust components for any marks following. */
866 for (unsigned int i = buffer->idx; i < buffer->len; i++) {
867 if (last_lig_id == _hb_glyph_info_get_lig_id (&buffer->info[i])) {
868 unsigned int new_lig_comp = components_so_far - last_num_components +
869 MIN (MAX (_hb_glyph_info_get_lig_comp (&buffer->info[i]), 1u), last_num_components);
870 _hb_glyph_info_set_lig_props_for_mark (&buffer->info[i], lig_id, new_lig_comp);
871 } else
872 break;
873 }
874 }
875 return_trace (true);
876 }
877
878 static inline bool match_backtrack (hb_apply_context_t *c,
879 unsigned int count,
880 const USHORT backtrack[],
881 match_func_t match_func,
882 const void *match_data)
883 {
884 TRACE_APPLY (NULL);
885
886 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
887 skippy_iter.reset (c->buffer->backtrack_len (), count);
888 skippy_iter.set_match_func (match_func, match_data, backtrack);
889
890 for (unsigned int i = 0; i < count; i++)
891 if (!skippy_iter.prev ())
892 return_trace (false);
893
894 return_trace (true);
895 }
896
897 static inline bool match_lookahead (hb_apply_context_t *c,
898 unsigned int count,
899 const USHORT lookahead[],
900 match_func_t match_func,
901 const void *match_data,
902 unsigned int offset)
903 {
904 TRACE_APPLY (NULL);
905
906 hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_context;
907 skippy_iter.reset (c->buffer->idx + offset - 1, count);
908 skippy_iter.set_match_func (match_func, match_data, lookahead);
909
910 for (unsigned int i = 0; i < count; i++)
911 if (!skippy_iter.next ())
912 return_trace (false);
913
914 return_trace (true);
915 }
916
917
918
919 struct LookupRecord
920 {
921 inline bool sanitize (hb_sanitize_context_t *c) const
922 {
923 TRACE_SANITIZE (this);
924 return_trace (c->check_struct (this));
925 }
926
927 USHORT sequenceIndex; /* Index into current glyph
928 * sequence--first glyph = 0 */
929 USHORT lookupListIndex; /* Lookup to apply to that
930 * position--zero--based */
931 public:
932 DEFINE_SIZE_STATIC (4);
933 };
934
935
936 template <typename context_t>
937 static inline void recurse_lookups (context_t *c,
938 unsigned int lookupCount,
939 const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
940 {
941 for (unsigned int i = 0; i < lookupCount; i++)
942 c->recurse (lookupRecord[i].lookupListIndex);
943 }
944
945 static inline bool apply_lookup (hb_apply_context_t *c,
946 unsigned int count, /* Including the first glyph */
947 unsigned int match_positions[MAX_CONTEXT_LENGTH], /* Including the first glyph */
948 unsigned int lookupCount,
949 const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */
950 unsigned int match_length)
951 {
952 TRACE_APPLY (NULL);
953
954 hb_buffer_t *buffer = c->buffer;
955 unsigned int end;
956
957 /* All positions are distance from beginning of *output* buffer.
958 * Adjust. */
959 {
960 unsigned int bl = buffer->backtrack_len ();
961 end = bl + match_length;
962
963 int delta = bl - buffer->idx;
964 /* Convert positions to new indexing. */
965 for (unsigned int j = 0; j < count; j++)
966 match_positions[j] += delta;
967 }
968
969 for (unsigned int i = 0; i < lookupCount; i++)
970 {
971 unsigned int idx = lookupRecord[i].sequenceIndex;
972 if (idx >= count)
973 continue;
974
975 buffer->move_to (match_positions[idx]);
976
977 unsigned int orig_len = buffer->backtrack_len () + buffer->lookahead_len ();
978 if (!c->recurse (lookupRecord[i].lookupListIndex))
979 continue;
980
981 unsigned int new_len = buffer->backtrack_len () + buffer->lookahead_len ();
982 int delta = new_len - orig_len;
983
984 if (!delta)
985 continue;
986
987 /* Recursed lookup changed buffer len. Adjust. */
988
989 /* end can't go back past the current match position.
990 * Note: this is only true because we do NOT allow MultipleSubst
991 * with zero sequence len. */
992 end = MAX ((int) match_positions[idx] + 1, int (end) + delta);
993
994 unsigned int next = idx + 1; /* next now is the position after the recursed lookup. */
995
996 if (delta > 0)
997 {
998 if (unlikely (delta + count > MAX_CONTEXT_LENGTH))
999 break;
1000 }
1001 else
1002 {
1003 /* NOTE: delta is negative. */
1004 delta = MAX (delta, (int) next - (int) count);
1005 next -= delta;
1006 }
1007
1008 /* Shift! */
1009 memmove (match_positions + next + delta, match_positions + next,
1010 (count - next) * sizeof (match_positions[0]));
1011 next += delta;
1012 count += delta;
1013
1014 /* Fill in new entries. */
1015 for (unsigned int j = idx + 1; j < next; j++)
1016 match_positions[j] = match_positions[j - 1] + 1;
1017
1018 /* And fixup the rest. */
1019 for (; next < count; next++)
1020 match_positions[next] += delta;
1021 }
1022
1023 buffer->move_to (end);
1024
1025 return_trace (true);
1026 }
1027
1028
1029
1030 /* Contextual lookups */
1031
1032 struct ContextClosureLookupContext
1033 {
1034 ContextClosureFuncs funcs;
1035 const void *intersects_data;
1036 };
1037
1038 struct ContextCollectGlyphsLookupContext
1039 {
1040 ContextCollectGlyphsFuncs funcs;
1041 const void *collect_data;
1042 };
1043
1044 struct ContextApplyLookupContext
1045 {
1046 ContextApplyFuncs funcs;
1047 const void *match_data;
1048 };
1049
1050 static inline void context_closure_lookup (hb_closure_context_t *c,
1051 unsigned int inputCount, /* Including the first glyph (not matched) */
1052 const USHORT input[], /* Array of input values--start with second glyph */
1053 unsigned int lookupCount,
1054 const LookupRecord lookupRecord[],
1055 ContextClosureLookupContext &lookup_context)
1056 {
1057 if (intersects_array (c,
1058 inputCount ? inputCount - 1 : 0, input,
1059 lookup_context.funcs.intersects, lookup_context.intersects_data))
1060 recurse_lookups (c,
1061 lookupCount, lookupRecord);
1062 }
1063
1064 static inline void context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1065 unsigned int inputCount, /* Including the first glyph (not matched) */
1066 const USHORT input[], /* Array of input values--start with second glyph */
1067 unsigned int lookupCount,
1068 const LookupRecord lookupRecord[],
1069 ContextCollectGlyphsLookupContext &lookup_context)
1070 {
1071 collect_array (c, c->input,
1072 inputCount ? inputCount - 1 : 0, input,
1073 lookup_context.funcs.collect, lookup_context.collect_data);
1074 recurse_lookups (c,
1075 lookupCount, lookupRecord);
1076 }
1077
1078 static inline bool context_would_apply_lookup (hb_would_apply_context_t *c,
1079 unsigned int inputCount, /* Including the first glyph (not matched) */
1080 const USHORT input[], /* Array of input values--start with second glyph */
1081 unsigned int lookupCount HB_UNUSED,
1082 const LookupRecord lookupRecord[] HB_UNUSED,
1083 ContextApplyLookupContext &lookup_context)
1084 {
1085 return would_match_input (c,
1086 inputCount, input,
1087 lookup_context.funcs.match, lookup_context.match_data);
1088 }
1089 static inline bool context_apply_lookup (hb_apply_context_t *c,
1090 unsigned int inputCount, /* Including the first glyph (not matched) */
1091 const USHORT input[], /* Array of input values--start with second glyph */
1092 unsigned int lookupCount,
1093 const LookupRecord lookupRecord[],
1094 ContextApplyLookupContext &lookup_context)
1095 {
1096 unsigned int match_length = 0;
1097 unsigned int match_positions[MAX_CONTEXT_LENGTH];
1098 return match_input (c,
1099 inputCount, input,
1100 lookup_context.funcs.match, lookup_context.match_data,
1101 &match_length, match_positions)
1102 && apply_lookup (c,
1103 inputCount, match_positions,
1104 lookupCount, lookupRecord,
1105 match_length);
1106 }
1107
1108 struct Rule
1109 {
1110 inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1111 {
1112 TRACE_CLOSURE (this);
1113 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1114 context_closure_lookup (c,
1115 inputCount, inputZ,
1116 lookupCount, lookupRecord,
1117 lookup_context);
1118 }
1119
1120 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1121 {
1122 TRACE_COLLECT_GLYPHS (this);
1123 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1124 context_collect_glyphs_lookup (c,
1125 inputCount, inputZ,
1126 lookupCount, lookupRecord,
1127 lookup_context);
1128 }
1129
1130 inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1131 {
1132 TRACE_WOULD_APPLY (this);
1133 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1134 return_trace (context_would_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1135 }
1136
1137 inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1138 {
1139 TRACE_APPLY (this);
1140 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (inputZ, inputZ[0].static_size * (inputCount ? inputCount - 1 : 0));
1141 return_trace (context_apply_lookup (c, inputCount, inputZ, lookupCount, lookupRecord, lookup_context));
1142 }
1143
1144 public:
1145 inline bool sanitize (hb_sanitize_context_t *c) const
1146 {
1147 TRACE_SANITIZE (this);
1148 return inputCount.sanitize (c)
1149 && lookupCount.sanitize (c)
1150 && c->check_range (inputZ,
1151 inputZ[0].static_size * inputCount
1152 + lookupRecordX[0].static_size * lookupCount);
1153 }
1154
1155 protected:
1156 USHORT inputCount; /* Total number of glyphs in input
1157 * glyph sequence--includes the first
1158 * glyph */
1159 USHORT lookupCount; /* Number of LookupRecords */
1160 USHORT inputZ[VAR]; /* Array of match inputs--start with
1161 * second glyph */
1162 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in
1163 * design order */
1164 public:
1165 DEFINE_SIZE_ARRAY2 (4, inputZ, lookupRecordX);
1166 };
1167
1168 struct RuleSet
1169 {
1170 inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
1171 {
1172 TRACE_CLOSURE (this);
1173 unsigned int num_rules = rule.len;
1174 for (unsigned int i = 0; i < num_rules; i++)
1175 (this+rule[i]).closure (c, lookup_context);
1176 }
1177
1178 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
1179 {
1180 TRACE_COLLECT_GLYPHS (this);
1181 unsigned int num_rules = rule.len;
1182 for (unsigned int i = 0; i < num_rules; i++)
1183 (this+rule[i]).collect_glyphs (c, lookup_context);
1184 }
1185
1186 inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1187 {
1188 TRACE_WOULD_APPLY (this);
1189 unsigned int num_rules = rule.len;
1190 for (unsigned int i = 0; i < num_rules; i++)
1191 {
1192 if ((this+rule[i]).would_apply (c, lookup_context))
1193 return_trace (true);
1194 }
1195 return_trace (false);
1196 }
1197
1198 inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
1199 {
1200 TRACE_APPLY (this);
1201 unsigned int num_rules = rule.len;
1202 for (unsigned int i = 0; i < num_rules; i++)
1203 {
1204 if ((this+rule[i]).apply (c, lookup_context))
1205 return_trace (true);
1206 }
1207 return_trace (false);
1208 }
1209
1210 inline bool sanitize (hb_sanitize_context_t *c) const
1211 {
1212 TRACE_SANITIZE (this);
1213 return_trace (rule.sanitize (c, this));
1214 }
1215
1216 protected:
1217 OffsetArrayOf<Rule>
1218 rule; /* Array of Rule tables
1219 * ordered by preference */
1220 public:
1221 DEFINE_SIZE_ARRAY (2, rule);
1222 };
1223
1224
1225 struct ContextFormat1
1226 {
1227 inline void closure (hb_closure_context_t *c) const
1228 {
1229 TRACE_CLOSURE (this);
1230
1231 const Coverage &cov = (this+coverage);
1232
1233 struct ContextClosureLookupContext lookup_context = {
1234 {intersects_glyph},
1235 NULL
1236 };
1237
1238 unsigned int count = ruleSet.len;
1239 for (unsigned int i = 0; i < count; i++)
1240 if (cov.intersects_coverage (c->glyphs, i)) {
1241 const RuleSet &rule_set = this+ruleSet[i];
1242 rule_set.closure (c, lookup_context);
1243 }
1244 }
1245
1246 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1247 {
1248 TRACE_COLLECT_GLYPHS (this);
1249 (this+coverage).add_coverage (c->input);
1250
1251 struct ContextCollectGlyphsLookupContext lookup_context = {
1252 {collect_glyph},
1253 NULL
1254 };
1255
1256 unsigned int count = ruleSet.len;
1257 for (unsigned int i = 0; i < count; i++)
1258 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1259 }
1260
1261 inline bool would_apply (hb_would_apply_context_t *c) const
1262 {
1263 TRACE_WOULD_APPLY (this);
1264
1265 const RuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1266 struct ContextApplyLookupContext lookup_context = {
1267 {match_glyph},
1268 NULL
1269 };
1270 return_trace (rule_set.would_apply (c, lookup_context));
1271 }
1272
1273 inline const Coverage &get_coverage (void) const
1274 {
1275 return this+coverage;
1276 }
1277
1278 inline bool apply (hb_apply_context_t *c) const
1279 {
1280 TRACE_APPLY (this);
1281 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1282 if (likely (index == NOT_COVERED))
1283 return_trace (false);
1284
1285 const RuleSet &rule_set = this+ruleSet[index];
1286 struct ContextApplyLookupContext lookup_context = {
1287 {match_glyph},
1288 NULL
1289 };
1290 return_trace (rule_set.apply (c, lookup_context));
1291 }
1292
1293 inline bool sanitize (hb_sanitize_context_t *c) const
1294 {
1295 TRACE_SANITIZE (this);
1296 return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1297 }
1298
1299 protected:
1300 USHORT format; /* Format identifier--format = 1 */
1301 OffsetTo<Coverage>
1302 coverage; /* Offset to Coverage table--from
1303 * beginning of table */
1304 OffsetArrayOf<RuleSet>
1305 ruleSet; /* Array of RuleSet tables
1306 * ordered by Coverage Index */
1307 public:
1308 DEFINE_SIZE_ARRAY (6, ruleSet);
1309 };
1310
1311
1312 struct ContextFormat2
1313 {
1314 inline void closure (hb_closure_context_t *c) const
1315 {
1316 TRACE_CLOSURE (this);
1317 if (!(this+coverage).intersects (c->glyphs))
1318 return;
1319
1320 const ClassDef &class_def = this+classDef;
1321
1322 struct ContextClosureLookupContext lookup_context = {
1323 {intersects_class},
1324 &class_def
1325 };
1326
1327 unsigned int count = ruleSet.len;
1328 for (unsigned int i = 0; i < count; i++)
1329 if (class_def.intersects_class (c->glyphs, i)) {
1330 const RuleSet &rule_set = this+ruleSet[i];
1331 rule_set.closure (c, lookup_context);
1332 }
1333 }
1334
1335 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1336 {
1337 TRACE_COLLECT_GLYPHS (this);
1338 (this+coverage).add_coverage (c->input);
1339
1340 const ClassDef &class_def = this+classDef;
1341 struct ContextCollectGlyphsLookupContext lookup_context = {
1342 {collect_class},
1343 &class_def
1344 };
1345
1346 unsigned int count = ruleSet.len;
1347 for (unsigned int i = 0; i < count; i++)
1348 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1349 }
1350
1351 inline bool would_apply (hb_would_apply_context_t *c) const
1352 {
1353 TRACE_WOULD_APPLY (this);
1354
1355 const ClassDef &class_def = this+classDef;
1356 unsigned int index = class_def.get_class (c->glyphs[0]);
1357 const RuleSet &rule_set = this+ruleSet[index];
1358 struct ContextApplyLookupContext lookup_context = {
1359 {match_class},
1360 &class_def
1361 };
1362 return_trace (rule_set.would_apply (c, lookup_context));
1363 }
1364
1365 inline const Coverage &get_coverage (void) const
1366 {
1367 return this+coverage;
1368 }
1369
1370 inline bool apply (hb_apply_context_t *c) const
1371 {
1372 TRACE_APPLY (this);
1373 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1374 if (likely (index == NOT_COVERED)) return_trace (false);
1375
1376 const ClassDef &class_def = this+classDef;
1377 index = class_def.get_class (c->buffer->cur().codepoint);
1378 const RuleSet &rule_set = this+ruleSet[index];
1379 struct ContextApplyLookupContext lookup_context = {
1380 {match_class},
1381 &class_def
1382 };
1383 return_trace (rule_set.apply (c, lookup_context));
1384 }
1385
1386 inline bool sanitize (hb_sanitize_context_t *c) const
1387 {
1388 TRACE_SANITIZE (this);
1389 return_trace (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this));
1390 }
1391
1392 protected:
1393 USHORT format; /* Format identifier--format = 2 */
1394 OffsetTo<Coverage>
1395 coverage; /* Offset to Coverage table--from
1396 * beginning of table */
1397 OffsetTo<ClassDef>
1398 classDef; /* Offset to glyph ClassDef table--from
1399 * beginning of table */
1400 OffsetArrayOf<RuleSet>
1401 ruleSet; /* Array of RuleSet tables
1402 * ordered by class */
1403 public:
1404 DEFINE_SIZE_ARRAY (8, ruleSet);
1405 };
1406
1407
1408 struct ContextFormat3
1409 {
1410 inline void closure (hb_closure_context_t *c) const
1411 {
1412 TRACE_CLOSURE (this);
1413 if (!(this+coverageZ[0]).intersects (c->glyphs))
1414 return;
1415
1416 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1417 struct ContextClosureLookupContext lookup_context = {
1418 {intersects_coverage},
1419 this
1420 };
1421 context_closure_lookup (c,
1422 glyphCount, (const USHORT *) (coverageZ + 1),
1423 lookupCount, lookupRecord,
1424 lookup_context);
1425 }
1426
1427 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1428 {
1429 TRACE_COLLECT_GLYPHS (this);
1430 (this+coverageZ[0]).add_coverage (c->input);
1431
1432 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1433 struct ContextCollectGlyphsLookupContext lookup_context = {
1434 {collect_coverage},
1435 this
1436 };
1437
1438 context_collect_glyphs_lookup (c,
1439 glyphCount, (const USHORT *) (coverageZ + 1),
1440 lookupCount, lookupRecord,
1441 lookup_context);
1442 }
1443
1444 inline bool would_apply (hb_would_apply_context_t *c) const
1445 {
1446 TRACE_WOULD_APPLY (this);
1447
1448 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * glyphCount);
1449 struct ContextApplyLookupContext lookup_context = {
1450 {match_coverage},
1451 this
1452 };
1453 return_trace (context_would_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1454 }
1455
1456 inline const Coverage &get_coverage (void) const
1457 {
1458 return this+coverageZ[0];
1459 }
1460
1461 inline bool apply (hb_apply_context_t *c) const
1462 {
1463 TRACE_APPLY (this);
1464 unsigned int index = (this+coverageZ[0]).get_coverage (c->buffer->cur().codepoint);
1465 if (likely (index == NOT_COVERED)) return_trace (false);
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_apply_lookup (c, glyphCount, (const USHORT *) (coverageZ + 1), lookupCount, lookupRecord, lookup_context));
1473 }
1474
1475 inline bool sanitize (hb_sanitize_context_t *c) const
1476 {
1477 TRACE_SANITIZE (this);
1478 if (!c->check_struct (this)) return_trace (false);
1479 unsigned int count = glyphCount;
1480 if (!count) return_trace (false); /* We want to access coverageZ[0] freely. */
1481 if (!c->check_array (coverageZ, coverageZ[0].static_size, count)) return_trace (false);
1482 for (unsigned int i = 0; i < count; i++)
1483 if (!coverageZ[i].sanitize (c, this)) return_trace (false);
1484 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverageZ, coverageZ[0].static_size * count);
1485 return_trace (c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount));
1486 }
1487
1488 protected:
1489 USHORT format; /* Format identifier--format = 3 */
1490 USHORT glyphCount; /* Number of glyphs in the input glyph
1491 * sequence */
1492 USHORT lookupCount; /* Number of LookupRecords */
1493 OffsetTo<Coverage>
1494 coverageZ[VAR]; /* Array of offsets to Coverage
1495 * table in glyph sequence order */
1496 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in
1497 * design order */
1498 public:
1499 DEFINE_SIZE_ARRAY2 (6, coverageZ, lookupRecordX);
1500 };
1501
1502 struct Context
1503 {
1504 template <typename context_t>
1505 inline typename context_t::return_t dispatch (context_t *c) const
1506 {
1507 TRACE_DISPATCH (this, u.format);
1508 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
1509 switch (u.format) {
1510 case 1: return_trace (c->dispatch (u.format1));
1511 case 2: return_trace (c->dispatch (u.format2));
1512 case 3: return_trace (c->dispatch (u.format3));
1513 default:return_trace (c->default_return_value ());
1514 }
1515 }
1516
1517 protected:
1518 union {
1519 USHORT format; /* Format identifier */
1520 ContextFormat1 format1;
1521 ContextFormat2 format2;
1522 ContextFormat3 format3;
1523 } u;
1524 };
1525
1526
1527 /* Chaining Contextual lookups */
1528
1529 struct ChainContextClosureLookupContext
1530 {
1531 ContextClosureFuncs funcs;
1532 const void *intersects_data[3];
1533 };
1534
1535 struct ChainContextCollectGlyphsLookupContext
1536 {
1537 ContextCollectGlyphsFuncs funcs;
1538 const void *collect_data[3];
1539 };
1540
1541 struct ChainContextApplyLookupContext
1542 {
1543 ContextApplyFuncs funcs;
1544 const void *match_data[3];
1545 };
1546
1547 static inline void chain_context_closure_lookup (hb_closure_context_t *c,
1548 unsigned int backtrackCount,
1549 const USHORT backtrack[],
1550 unsigned int inputCount, /* Including the first glyph (not matched) */
1551 const USHORT input[], /* Array of input values--start with second glyph */
1552 unsigned int lookaheadCount,
1553 const USHORT lookahead[],
1554 unsigned int lookupCount,
1555 const LookupRecord lookupRecord[],
1556 ChainContextClosureLookupContext &lookup_context)
1557 {
1558 if (intersects_array (c,
1559 backtrackCount, backtrack,
1560 lookup_context.funcs.intersects, lookup_context.intersects_data[0])
1561 && intersects_array (c,
1562 inputCount ? inputCount - 1 : 0, input,
1563 lookup_context.funcs.intersects, lookup_context.intersects_data[1])
1564 && intersects_array (c,
1565 lookaheadCount, lookahead,
1566 lookup_context.funcs.intersects, lookup_context.intersects_data[2]))
1567 recurse_lookups (c,
1568 lookupCount, lookupRecord);
1569 }
1570
1571 static inline void chain_context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
1572 unsigned int backtrackCount,
1573 const USHORT backtrack[],
1574 unsigned int inputCount, /* Including the first glyph (not matched) */
1575 const USHORT input[], /* Array of input values--start with second glyph */
1576 unsigned int lookaheadCount,
1577 const USHORT lookahead[],
1578 unsigned int lookupCount,
1579 const LookupRecord lookupRecord[],
1580 ChainContextCollectGlyphsLookupContext &lookup_context)
1581 {
1582 collect_array (c, c->before,
1583 backtrackCount, backtrack,
1584 lookup_context.funcs.collect, lookup_context.collect_data[0]);
1585 collect_array (c, c->input,
1586 inputCount ? inputCount - 1 : 0, input,
1587 lookup_context.funcs.collect, lookup_context.collect_data[1]);
1588 collect_array (c, c->after,
1589 lookaheadCount, lookahead,
1590 lookup_context.funcs.collect, lookup_context.collect_data[2]);
1591 recurse_lookups (c,
1592 lookupCount, lookupRecord);
1593 }
1594
1595 static inline bool chain_context_would_apply_lookup (hb_would_apply_context_t *c,
1596 unsigned int backtrackCount,
1597 const USHORT backtrack[] HB_UNUSED,
1598 unsigned int inputCount, /* Including the first glyph (not matched) */
1599 const USHORT input[], /* Array of input values--start with second glyph */
1600 unsigned int lookaheadCount,
1601 const USHORT lookahead[] HB_UNUSED,
1602 unsigned int lookupCount HB_UNUSED,
1603 const LookupRecord lookupRecord[] HB_UNUSED,
1604 ChainContextApplyLookupContext &lookup_context)
1605 {
1606 return (c->zero_context ? !backtrackCount && !lookaheadCount : true)
1607 && would_match_input (c,
1608 inputCount, input,
1609 lookup_context.funcs.match, lookup_context.match_data[1]);
1610 }
1611
1612 static inline bool chain_context_apply_lookup (hb_apply_context_t *c,
1613 unsigned int backtrackCount,
1614 const USHORT backtrack[],
1615 unsigned int inputCount, /* Including the first glyph (not matched) */
1616 const USHORT input[], /* Array of input values--start with second glyph */
1617 unsigned int lookaheadCount,
1618 const USHORT lookahead[],
1619 unsigned int lookupCount,
1620 const LookupRecord lookupRecord[],
1621 ChainContextApplyLookupContext &lookup_context)
1622 {
1623 unsigned int match_length = 0;
1624 unsigned int match_positions[MAX_CONTEXT_LENGTH];
1625 return match_input (c,
1626 inputCount, input,
1627 lookup_context.funcs.match, lookup_context.match_data[1],
1628 &match_length, match_positions)
1629 && match_backtrack (c,
1630 backtrackCount, backtrack,
1631 lookup_context.funcs.match, lookup_context.match_data[0])
1632 && match_lookahead (c,
1633 lookaheadCount, lookahead,
1634 lookup_context.funcs.match, lookup_context.match_data[2],
1635 match_length)
1636 && apply_lookup (c,
1637 inputCount, match_positions,
1638 lookupCount, lookupRecord,
1639 match_length);
1640 }
1641
1642 struct ChainRule
1643 {
1644 inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1645 {
1646 TRACE_CLOSURE (this);
1647 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1648 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1649 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1650 chain_context_closure_lookup (c,
1651 backtrack.len, backtrack.array,
1652 input.len, input.array,
1653 lookahead.len, lookahead.array,
1654 lookup.len, lookup.array,
1655 lookup_context);
1656 }
1657
1658 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1659 {
1660 TRACE_COLLECT_GLYPHS (this);
1661 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1662 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1663 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1664 chain_context_collect_glyphs_lookup (c,
1665 backtrack.len, backtrack.array,
1666 input.len, input.array,
1667 lookahead.len, lookahead.array,
1668 lookup.len, lookup.array,
1669 lookup_context);
1670 }
1671
1672 inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1673 {
1674 TRACE_WOULD_APPLY (this);
1675 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1676 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1677 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1678 return_trace (chain_context_would_apply_lookup (c,
1679 backtrack.len, backtrack.array,
1680 input.len, input.array,
1681 lookahead.len, lookahead.array, lookup.len,
1682 lookup.array, lookup_context));
1683 }
1684
1685 inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1686 {
1687 TRACE_APPLY (this);
1688 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1689 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1690 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1691 return_trace (chain_context_apply_lookup (c,
1692 backtrack.len, backtrack.array,
1693 input.len, input.array,
1694 lookahead.len, lookahead.array, lookup.len,
1695 lookup.array, lookup_context));
1696 }
1697
1698 inline bool sanitize (hb_sanitize_context_t *c) const
1699 {
1700 TRACE_SANITIZE (this);
1701 if (!backtrack.sanitize (c)) return_trace (false);
1702 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
1703 if (!input.sanitize (c)) return_trace (false);
1704 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
1705 if (!lookahead.sanitize (c)) return_trace (false);
1706 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
1707 return_trace (lookup.sanitize (c));
1708 }
1709
1710 protected:
1711 ArrayOf<USHORT>
1712 backtrack; /* Array of backtracking values
1713 * (to be matched before the input
1714 * sequence) */
1715 HeadlessArrayOf<USHORT>
1716 inputX; /* Array of input values (start with
1717 * second glyph) */
1718 ArrayOf<USHORT>
1719 lookaheadX; /* Array of lookahead values's (to be
1720 * matched after the input sequence) */
1721 ArrayOf<LookupRecord>
1722 lookupX; /* Array of LookupRecords--in
1723 * design order) */
1724 public:
1725 DEFINE_SIZE_MIN (8);
1726 };
1727
1728 struct ChainRuleSet
1729 {
1730 inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
1731 {
1732 TRACE_CLOSURE (this);
1733 unsigned int num_rules = rule.len;
1734 for (unsigned int i = 0; i < num_rules; i++)
1735 (this+rule[i]).closure (c, lookup_context);
1736 }
1737
1738 inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
1739 {
1740 TRACE_COLLECT_GLYPHS (this);
1741 unsigned int num_rules = rule.len;
1742 for (unsigned int i = 0; i < num_rules; i++)
1743 (this+rule[i]).collect_glyphs (c, lookup_context);
1744 }
1745
1746 inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1747 {
1748 TRACE_WOULD_APPLY (this);
1749 unsigned int num_rules = rule.len;
1750 for (unsigned int i = 0; i < num_rules; i++)
1751 if ((this+rule[i]).would_apply (c, lookup_context))
1752 return_trace (true);
1753
1754 return_trace (false);
1755 }
1756
1757 inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
1758 {
1759 TRACE_APPLY (this);
1760 unsigned int num_rules = rule.len;
1761 for (unsigned int i = 0; i < num_rules; i++)
1762 if ((this+rule[i]).apply (c, lookup_context))
1763 return_trace (true);
1764
1765 return_trace (false);
1766 }
1767
1768 inline bool sanitize (hb_sanitize_context_t *c) const
1769 {
1770 TRACE_SANITIZE (this);
1771 return_trace (rule.sanitize (c, this));
1772 }
1773
1774 protected:
1775 OffsetArrayOf<ChainRule>
1776 rule; /* Array of ChainRule tables
1777 * ordered by preference */
1778 public:
1779 DEFINE_SIZE_ARRAY (2, rule);
1780 };
1781
1782 struct ChainContextFormat1
1783 {
1784 inline void closure (hb_closure_context_t *c) const
1785 {
1786 TRACE_CLOSURE (this);
1787 const Coverage &cov = (this+coverage);
1788
1789 struct ChainContextClosureLookupContext lookup_context = {
1790 {intersects_glyph},
1791 {NULL, NULL, NULL}
1792 };
1793
1794 unsigned int count = ruleSet.len;
1795 for (unsigned int i = 0; i < count; i++)
1796 if (cov.intersects_coverage (c->glyphs, i)) {
1797 const ChainRuleSet &rule_set = this+ruleSet[i];
1798 rule_set.closure (c, lookup_context);
1799 }
1800 }
1801
1802 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1803 {
1804 TRACE_COLLECT_GLYPHS (this);
1805 (this+coverage).add_coverage (c->input);
1806
1807 struct ChainContextCollectGlyphsLookupContext lookup_context = {
1808 {collect_glyph},
1809 {NULL, NULL, NULL}
1810 };
1811
1812 unsigned int count = ruleSet.len;
1813 for (unsigned int i = 0; i < count; i++)
1814 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1815 }
1816
1817 inline bool would_apply (hb_would_apply_context_t *c) const
1818 {
1819 TRACE_WOULD_APPLY (this);
1820
1821 const ChainRuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
1822 struct ChainContextApplyLookupContext lookup_context = {
1823 {match_glyph},
1824 {NULL, NULL, NULL}
1825 };
1826 return_trace (rule_set.would_apply (c, lookup_context));
1827 }
1828
1829 inline const Coverage &get_coverage (void) const
1830 {
1831 return this+coverage;
1832 }
1833
1834 inline bool apply (hb_apply_context_t *c) const
1835 {
1836 TRACE_APPLY (this);
1837 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1838 if (likely (index == NOT_COVERED)) return_trace (false);
1839
1840 const ChainRuleSet &rule_set = this+ruleSet[index];
1841 struct ChainContextApplyLookupContext lookup_context = {
1842 {match_glyph},
1843 {NULL, NULL, NULL}
1844 };
1845 return_trace (rule_set.apply (c, lookup_context));
1846 }
1847
1848 inline bool sanitize (hb_sanitize_context_t *c) const
1849 {
1850 TRACE_SANITIZE (this);
1851 return_trace (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
1852 }
1853
1854 protected:
1855 USHORT format; /* Format identifier--format = 1 */
1856 OffsetTo<Coverage>
1857 coverage; /* Offset to Coverage table--from
1858 * beginning of table */
1859 OffsetArrayOf<ChainRuleSet>
1860 ruleSet; /* Array of ChainRuleSet tables
1861 * ordered by Coverage Index */
1862 public:
1863 DEFINE_SIZE_ARRAY (6, ruleSet);
1864 };
1865
1866 struct ChainContextFormat2
1867 {
1868 inline void closure (hb_closure_context_t *c) const
1869 {
1870 TRACE_CLOSURE (this);
1871 if (!(this+coverage).intersects (c->glyphs))
1872 return;
1873
1874 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1875 const ClassDef &input_class_def = this+inputClassDef;
1876 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1877
1878 struct ChainContextClosureLookupContext lookup_context = {
1879 {intersects_class},
1880 {&backtrack_class_def,
1881 &input_class_def,
1882 &lookahead_class_def}
1883 };
1884
1885 unsigned int count = ruleSet.len;
1886 for (unsigned int i = 0; i < count; i++)
1887 if (input_class_def.intersects_class (c->glyphs, i)) {
1888 const ChainRuleSet &rule_set = this+ruleSet[i];
1889 rule_set.closure (c, lookup_context);
1890 }
1891 }
1892
1893 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
1894 {
1895 TRACE_COLLECT_GLYPHS (this);
1896 (this+coverage).add_coverage (c->input);
1897
1898 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1899 const ClassDef &input_class_def = this+inputClassDef;
1900 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1901
1902 struct ChainContextCollectGlyphsLookupContext lookup_context = {
1903 {collect_class},
1904 {&backtrack_class_def,
1905 &input_class_def,
1906 &lookahead_class_def}
1907 };
1908
1909 unsigned int count = ruleSet.len;
1910 for (unsigned int i = 0; i < count; i++)
1911 (this+ruleSet[i]).collect_glyphs (c, lookup_context);
1912 }
1913
1914 inline bool would_apply (hb_would_apply_context_t *c) const
1915 {
1916 TRACE_WOULD_APPLY (this);
1917
1918 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1919 const ClassDef &input_class_def = this+inputClassDef;
1920 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1921
1922 unsigned int index = input_class_def.get_class (c->glyphs[0]);
1923 const ChainRuleSet &rule_set = this+ruleSet[index];
1924 struct ChainContextApplyLookupContext lookup_context = {
1925 {match_class},
1926 {&backtrack_class_def,
1927 &input_class_def,
1928 &lookahead_class_def}
1929 };
1930 return_trace (rule_set.would_apply (c, lookup_context));
1931 }
1932
1933 inline const Coverage &get_coverage (void) const
1934 {
1935 return this+coverage;
1936 }
1937
1938 inline bool apply (hb_apply_context_t *c) const
1939 {
1940 TRACE_APPLY (this);
1941 unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
1942 if (likely (index == NOT_COVERED)) return_trace (false);
1943
1944 const ClassDef &backtrack_class_def = this+backtrackClassDef;
1945 const ClassDef &input_class_def = this+inputClassDef;
1946 const ClassDef &lookahead_class_def = this+lookaheadClassDef;
1947
1948 index = input_class_def.get_class (c->buffer->cur().codepoint);
1949 const ChainRuleSet &rule_set = this+ruleSet[index];
1950 struct ChainContextApplyLookupContext lookup_context = {
1951 {match_class},
1952 {&backtrack_class_def,
1953 &input_class_def,
1954 &lookahead_class_def}
1955 };
1956 return_trace (rule_set.apply (c, lookup_context));
1957 }
1958
1959 inline bool sanitize (hb_sanitize_context_t *c) const
1960 {
1961 TRACE_SANITIZE (this);
1962 return_trace (coverage.sanitize (c, this) &&
1963 backtrackClassDef.sanitize (c, this) &&
1964 inputClassDef.sanitize (c, this) &&
1965 lookaheadClassDef.sanitize (c, this) &&
1966 ruleSet.sanitize (c, this));
1967 }
1968
1969 protected:
1970 USHORT format; /* Format identifier--format = 2 */
1971 OffsetTo<Coverage>
1972 coverage; /* Offset to Coverage table--from
1973 * beginning of table */
1974 OffsetTo<ClassDef>
1975 backtrackClassDef; /* Offset to glyph ClassDef table
1976 * containing backtrack sequence
1977 * data--from beginning of table */
1978 OffsetTo<ClassDef>
1979 inputClassDef; /* Offset to glyph ClassDef
1980 * table containing input sequence
1981 * data--from beginning of table */
1982 OffsetTo<ClassDef>
1983 lookaheadClassDef; /* Offset to glyph ClassDef table
1984 * containing lookahead sequence
1985 * data--from beginning of table */
1986 OffsetArrayOf<ChainRuleSet>
1987 ruleSet; /* Array of ChainRuleSet tables
1988 * ordered by class */
1989 public:
1990 DEFINE_SIZE_ARRAY (12, ruleSet);
1991 };
1992
1993 struct ChainContextFormat3
1994 {
1995 inline void closure (hb_closure_context_t *c) const
1996 {
1997 TRACE_CLOSURE (this);
1998 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
1999
2000 if (!(this+input[0]).intersects (c->glyphs))
2001 return;
2002
2003 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2004 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2005 struct ChainContextClosureLookupContext lookup_context = {
2006 {intersects_coverage},
2007 {this, this, this}
2008 };
2009 chain_context_closure_lookup (c,
2010 backtrack.len, (const USHORT *) backtrack.array,
2011 input.len, (const USHORT *) input.array + 1,
2012 lookahead.len, (const USHORT *) lookahead.array,
2013 lookup.len, lookup.array,
2014 lookup_context);
2015 }
2016
2017 inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
2018 {
2019 TRACE_COLLECT_GLYPHS (this);
2020 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2021
2022 (this+input[0]).add_coverage (c->input);
2023
2024 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2025 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2026 struct ChainContextCollectGlyphsLookupContext lookup_context = {
2027 {collect_coverage},
2028 {this, this, this}
2029 };
2030 chain_context_collect_glyphs_lookup (c,
2031 backtrack.len, (const USHORT *) backtrack.array,
2032 input.len, (const USHORT *) input.array + 1,
2033 lookahead.len, (const USHORT *) lookahead.array,
2034 lookup.len, lookup.array,
2035 lookup_context);
2036 }
2037
2038 inline bool would_apply (hb_would_apply_context_t *c) const
2039 {
2040 TRACE_WOULD_APPLY (this);
2041
2042 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2043 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2044 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2045 struct ChainContextApplyLookupContext lookup_context = {
2046 {match_coverage},
2047 {this, this, this}
2048 };
2049 return_trace (chain_context_would_apply_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, lookup_context));
2054 }
2055
2056 inline const Coverage &get_coverage (void) const
2057 {
2058 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2059 return this+input[0];
2060 }
2061
2062 inline bool apply (hb_apply_context_t *c) const
2063 {
2064 TRACE_APPLY (this);
2065 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2066
2067 unsigned int index = (this+input[0]).get_coverage (c->buffer->cur().codepoint);
2068 if (likely (index == NOT_COVERED)) return_trace (false);
2069
2070 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2071 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2072 struct ChainContextApplyLookupContext lookup_context = {
2073 {match_coverage},
2074 {this, this, this}
2075 };
2076 return_trace (chain_context_apply_lookup (c,
2077 backtrack.len, (const USHORT *) backtrack.array,
2078 input.len, (const USHORT *) input.array + 1,
2079 lookahead.len, (const USHORT *) lookahead.array,
2080 lookup.len, lookup.array, lookup_context));
2081 }
2082
2083 inline bool sanitize (hb_sanitize_context_t *c) const
2084 {
2085 TRACE_SANITIZE (this);
2086 if (!backtrack.sanitize (c, this)) return_trace (false);
2087 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
2088 if (!input.sanitize (c, this)) return_trace (false);
2089 if (!input.len) return_trace (false); /* To be consistent with Context. */
2090 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
2091 if (!lookahead.sanitize (c, this)) return_trace (false);
2092 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
2093 return_trace (lookup.sanitize (c));
2094 }
2095
2096 protected:
2097 USHORT format; /* Format identifier--format = 3 */
2098 OffsetArrayOf<Coverage>
2099 backtrack; /* Array of coverage tables
2100 * in backtracking sequence, in glyph
2101 * sequence order */
2102 OffsetArrayOf<Coverage>
2103 inputX ; /* Array of coverage
2104 * tables in input sequence, in glyph
2105 * sequence order */
2106 OffsetArrayOf<Coverage>
2107 lookaheadX; /* Array of coverage tables
2108 * in lookahead sequence, in glyph
2109 * sequence order */
2110 ArrayOf<LookupRecord>
2111 lookupX; /* Array of LookupRecords--in
2112 * design order) */
2113 public:
2114 DEFINE_SIZE_MIN (10);
2115 };
2116
2117 struct ChainContext
2118 {
2119 template <typename context_t>
2120 inline typename context_t::return_t dispatch (context_t *c) const
2121 {
2122 TRACE_DISPATCH (this, u.format);
2123 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
2124 switch (u.format) {
2125 case 1: return_trace (c->dispatch (u.format1));
2126 case 2: return_trace (c->dispatch (u.format2));
2127 case 3: return_trace (c->dispatch (u.format3));
2128 default:return_trace (c->default_return_value ());
2129 }
2130 }
2131
2132 protected:
2133 union {
2134 USHORT format; /* Format identifier */
2135 ChainContextFormat1 format1;
2136 ChainContextFormat2 format2;
2137 ChainContextFormat3 format3;
2138 } u;
2139 };
2140
2141
2142 template <typename T>
2143 struct ExtensionFormat1
2144 {
2145 inline unsigned int get_type (void) const { return extensionLookupType; }
2146
2147 template <typename X>
2148 inline const X& get_subtable (void) const
2149 {
2150 unsigned int offset = extensionOffset;
2151 if (unlikely (!offset)) return Null(typename T::LookupSubTable);
2152 return StructAtOffset<typename T::LookupSubTable> (this, offset);
2153 }
2154
2155 template <typename context_t>
2156 inline typename context_t::return_t dispatch (context_t *c) const
2157 {
2158 TRACE_DISPATCH (this, format);
2159 if (unlikely (!c->may_dispatch (this, this))) return_trace (c->no_dispatch_return_value ());
2160 return_trace (get_subtable<typename T::LookupSubTable> ().dispatch (c, get_type ()));
2161 }
2162
2163 /* This is called from may_dispatch() above with hb_sanitize_context_t. */
2164 inline bool sanitize (hb_sanitize_context_t *c) const
2165 {
2166 TRACE_SANITIZE (this);
2167 return_trace (c->check_struct (this) && extensionOffset != 0);
2168 }
2169
2170 protected:
2171 USHORT format; /* Format identifier. Set to 1. */
2172 USHORT extensionLookupType; /* Lookup type of subtable referenced
2173 * by ExtensionOffset (i.e. the
2174 * extension subtable). */
2175 ULONG extensionOffset; /* Offset to the extension subtable,
2176 * of lookup type subtable. */
2177 public:
2178 DEFINE_SIZE_STATIC (8);
2179 };
2180
2181 template <typename T>
2182 struct Extension
2183 {
2184 inline unsigned int get_type (void) const
2185 {
2186 switch (u.format) {
2187 case 1: return u.format1.get_type ();
2188 default:return 0;
2189 }
2190 }
2191 template <typename X>
2192 inline const X& get_subtable (void) const
2193 {
2194 switch (u.format) {
2195 case 1: return u.format1.template get_subtable<typename T::LookupSubTable> ();
2196 default:return Null(typename T::LookupSubTable);
2197 }
2198 }
2199
2200 template <typename context_t>
2201 inline typename context_t::return_t dispatch (context_t *c) const
2202 {
2203 TRACE_DISPATCH (this, u.format);
2204 if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
2205 switch (u.format) {
2206 case 1: return_trace (u.format1.dispatch (c));
2207 default:return_trace (c->default_return_value ());
2208 }
2209 }
2210
2211 protected:
2212 union {
2213 USHORT format; /* Format identifier */
2214 ExtensionFormat1<T> format1;
2215 } u;
2216 };
2217
2218
2219 /*
2220 * GSUB/GPOS Common
2221 */
2222
2223 struct GSUBGPOS
2224 {
2225 static const hb_tag_t GSUBTag = HB_OT_TAG_GSUB;
2226 static const hb_tag_t GPOSTag = HB_OT_TAG_GPOS;
2227
2228 inline unsigned int get_script_count (void) const
2229 { return (this+scriptList).len; }
2230 inline const Tag& get_script_tag (unsigned int i) const
2231 { return (this+scriptList).get_tag (i); }
2232 inline unsigned int get_script_tags (unsigned int start_offset,
2233 unsigned int *script_count /* IN/OUT */,
2234 hb_tag_t *script_tags /* OUT */) const
2235 { return (this+scriptList).get_tags (start_offset, script_count, script_tags); }
2236 inline const Script& get_script (unsigned int i) const
2237 { return (this+scriptList)[i]; }
2238 inline bool find_script_index (hb_tag_t tag, unsigned int *index) const
2239 { return (this+scriptList).find_index (tag, index); }
2240
2241 inline unsigned int get_feature_count (void) const
2242 { return (this+featureList).len; }
2243 inline hb_tag_t get_feature_tag (unsigned int i) const
2244 { return i == Index::NOT_FOUND_INDEX ? HB_TAG_NONE : (this+featureList).get_tag (i); }
2245 inline unsigned int get_feature_tags (unsigned int start_offset,
2246 unsigned int *feature_count /* IN/OUT */,
2247 hb_tag_t *feature_tags /* OUT */) const
2248 { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); }
2249 inline const Feature& get_feature (unsigned int i) const
2250 { return (this+featureList)[i]; }
2251 inline bool find_feature_index (hb_tag_t tag, unsigned int *index) const
2252 { return (this+featureList).find_index (tag, index); }
2253
2254 inline unsigned int get_lookup_count (void) const
2255 { return (this+lookupList).len; }
2256 inline const Lookup& get_lookup (unsigned int i) const
2257 { return (this+lookupList)[i]; }
2258
2259 inline bool sanitize (hb_sanitize_context_t *c) const
2260 {
2261 TRACE_SANITIZE (this);
2262 return_trace (version.sanitize (c) &&
2263 likely (version.major == 1) &&
2264 scriptList.sanitize (c, this) &&
2265 featureList.sanitize (c, this) &&
2266 lookupList.sanitize (c, this));
2267 }
2268
2269 protected:
2270 FixedVersion version; /* Version of the GSUB/GPOS table--initially set
2271 * to 0x00010000u */
2272 OffsetTo<ScriptList>
2273 scriptList; /* ScriptList table */
2274 OffsetTo<FeatureList>
2275 featureList; /* FeatureList table */
2276 OffsetTo<LookupList>
2277 lookupList; /* LookupList table */
2278 public:
2279 DEFINE_SIZE_STATIC (10);
2280 };
2281
2282
2283 } /* namespace OT */
2284
2285
2286 #endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */