1 /*
2 * Copyright © 2009,2010 Red Hat, Inc.
3 * Copyright © 2010,2011,2012 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 #define HB_SHAPER ot
30 #define hb_ot_shaper_face_data_t hb_ot_layout_t
31 #define hb_ot_shaper_shape_plan_data_t hb_ot_shape_plan_t
32 #include "hb-shaper-impl-private.hh"
33
34 #include "hb-ot-shape-private.hh"
35 #include "hb-ot-shape-complex-private.hh"
36 #include "hb-ot-shape-fallback-private.hh"
37 #include "hb-ot-shape-normalize-private.hh"
38
39 #include "hb-ot-layout-private.hh"
40 #include "hb-unicode-private.hh"
41 #include "hb-set-private.hh"
42
43 #include "hb-ot-layout-gsubgpos-private.hh"
44 //#include "hb-aat-layout-private.hh"
45
46 static hb_tag_t common_features[] = {
47 HB_TAG('c','c','m','p'),
48 HB_TAG('l','o','c','l'),
49 HB_TAG('m','a','r','k'),
50 HB_TAG('m','k','m','k'),
51 HB_TAG('r','l','i','g'),
52 };
53
54
55 static hb_tag_t horizontal_features[] = {
56 HB_TAG('c','a','l','t'),
57 HB_TAG('c','l','i','g'),
58 HB_TAG('c','u','r','s'),
59 HB_TAG('k','e','r','n'),
60 HB_TAG('l','i','g','a'),
61 HB_TAG('r','c','l','t'),
62 };
63
64
65
66 static void
67 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
68 const hb_segment_properties_t *props,
69 const hb_feature_t *user_features,
70 unsigned int num_user_features)
71 {
72 hb_ot_map_builder_t *map = &planner->map;
73
74 map->add_global_bool_feature (HB_TAG('r','v','r','n'));
75 map->add_gsub_pause (nullptr);
76
77 switch (props->direction) {
78 case HB_DIRECTION_LTR:
79 map->add_global_bool_feature (HB_TAG ('l','t','r','a'));
80 map->add_global_bool_feature (HB_TAG ('l','t','r','m'));
81 break;
82 case HB_DIRECTION_RTL:
83 map->add_global_bool_feature (HB_TAG ('r','t','l','a'));
84 map->add_feature (HB_TAG ('r','t','l','m'), 1, F_NONE);
85 break;
86 case HB_DIRECTION_TTB:
87 case HB_DIRECTION_BTT:
88 case HB_DIRECTION_INVALID:
89 default:
90 break;
91 }
92
93 map->add_feature (HB_TAG ('f','r','a','c'), 1, F_NONE);
94 map->add_feature (HB_TAG ('n','u','m','r'), 1, F_NONE);
95 map->add_feature (HB_TAG ('d','n','o','m'), 1, F_NONE);
96
97 if (planner->shaper->collect_features)
98 planner->shaper->collect_features (planner);
99
100 for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
101 map->add_global_bool_feature (common_features[i]);
102
103 if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
104 for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
105 map->add_feature (horizontal_features[i], 1, F_GLOBAL |
106 (horizontal_features[i] == HB_TAG('k','e','r','n') ?
107 F_HAS_FALLBACK : F_NONE));
108 else
109 {
110 /* We really want to find a 'vert' feature if there's any in the font, no
111 * matter which script/langsys it is listed (or not) under.
112 * See various bugs referenced from:
113 * https://github.com/harfbuzz/harfbuzz/issues/63 */
114 map->add_feature (HB_TAG ('v','e','r','t'), 1, F_GLOBAL | F_GLOBAL_SEARCH);
115 }
116
117 if (planner->shaper->override_features)
118 planner->shaper->override_features (planner);
119
120 for (unsigned int i = 0; i < num_user_features; i++) {
121 const hb_feature_t *feature = &user_features[i];
122 map->add_feature (feature->tag, feature->value,
123 (feature->start == 0 && feature->end == (unsigned int) -1) ?
124 F_GLOBAL : F_NONE);
125 }
126 }
127
128
129 /*
130 * shaper face data
131 */
132
133 HB_SHAPER_DATA_ENSURE_DEFINE(ot, face)
134
135 hb_ot_shaper_face_data_t *
136 _hb_ot_shaper_face_data_create (hb_face_t *face)
137 {
138 return _hb_ot_layout_create (face);
139 }
140
141 void
142 _hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data)
143 {
144 _hb_ot_layout_destroy (data);
145 }
146
147
148 /*
149 * shaper font data
150 */
151
152 HB_SHAPER_DATA_ENSURE_DEFINE(ot, font)
153
154 struct hb_ot_shaper_font_data_t {};
155
156 hb_ot_shaper_font_data_t *
157 _hb_ot_shaper_font_data_create (hb_font_t *font HB_UNUSED)
158 {
159 return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
160 }
161
162 void
163 _hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data)
164 {
165 }
166
167
168 /*
169 * shaper shape_plan data
170 */
171
172 hb_ot_shaper_shape_plan_data_t *
173 _hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan,
174 const hb_feature_t *user_features,
175 unsigned int num_user_features,
176 const int *coords,
177 unsigned int num_coords)
178 {
179 hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t));
180 if (unlikely (!plan))
181 return nullptr;
182
183 plan->init ();
184
185 hb_ot_shape_planner_t planner (shape_plan);
186
187 planner.shaper = hb_ot_shape_complex_categorize (&planner);
188
189 hb_ot_shape_collect_features (&planner, &shape_plan->props,
190 user_features, num_user_features);
191
192 planner.compile (*plan, coords, num_coords);
193
194 if (plan->shaper->data_create) {
195 plan->data = plan->shaper->data_create (plan);
196 if (unlikely (!plan->data))
197 return nullptr;
198 }
199
200 return plan;
201 }
202
203 void
204 _hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan)
205 {
206 if (plan->shaper->data_destroy)
207 plan->shaper->data_destroy (const_cast<void *> (plan->data));
208
209 plan->fini ();
210
211 free (plan);
212 }
213
214
215 /*
216 * shaper
217 */
218
219 struct hb_ot_shape_context_t
220 {
221 hb_ot_shape_plan_t *plan;
222 hb_font_t *font;
223 hb_face_t *face;
224 hb_buffer_t *buffer;
225 const hb_feature_t *user_features;
226 unsigned int num_user_features;
227
228 /* Transient stuff */
229 bool fallback_positioning;
230 bool fallback_glyph_classes;
231 hb_direction_t target_direction;
232 };
233
234
235
236 /* Main shaper */
237
238
239 /* Prepare */
240
241 static void
242 hb_set_unicode_props (hb_buffer_t *buffer)
243 {
244 unsigned int count = buffer->len;
245 hb_glyph_info_t *info = buffer->info;
246 for (unsigned int i = 0; i < count; i++)
247 _hb_glyph_info_set_unicode_props (&info[i], buffer);
248 }
249
250 static void
251 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
252 {
253 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
254 buffer->context_len[0] ||
255 _hb_glyph_info_get_general_category (&buffer->info[0]) !=
256 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
257 return;
258
259 if (!font->has_glyph (0x25CCu))
260 return;
261
262 hb_glyph_info_t dottedcircle = {0};
263 dottedcircle.codepoint = 0x25CCu;
264 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer);
265
266 buffer->clear_output ();
267
268 buffer->idx = 0;
269 hb_glyph_info_t info = dottedcircle;
270 info.cluster = buffer->cur().cluster;
271 info.mask = buffer->cur().mask;
272 buffer->output_info (info);
273 while (buffer->idx < buffer->len && buffer->successful)
274 buffer->next_glyph ();
275
276 buffer->swap_buffers ();
277 }
278
279 static void
280 hb_form_clusters (hb_buffer_t *buffer)
281 {
282 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII))
283 return;
284
285 /* Loop duplicated in hb_ensure_native_direction(), and in _hb-coretext.cc */
286 unsigned int base = 0;
287 unsigned int count = buffer->len;
288 hb_glyph_info_t *info = buffer->info;
289 for (unsigned int i = 1; i < count; i++)
290 {
291 if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i])) &&
292 !_hb_glyph_info_is_joiner (&info[i])))
293 {
294 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
295 buffer->merge_clusters (base, i);
296 else
297 buffer->unsafe_to_break (base, i);
298 base = i;
299 }
300 }
301 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
302 buffer->merge_clusters (base, count);
303 else
304 buffer->unsafe_to_break (base, count);
305 }
306
307 static void
308 hb_ensure_native_direction (hb_buffer_t *buffer)
309 {
310 hb_direction_t direction = buffer->props.direction;
311 hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
312
313 /* TODO vertical:
314 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
315 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
316 * first. */
317 if ((HB_DIRECTION_IS_HORIZONTAL (direction) &&
318 direction != horiz_dir && horiz_dir != HB_DIRECTION_INVALID) ||
319 (HB_DIRECTION_IS_VERTICAL (direction) &&
320 direction != HB_DIRECTION_TTB))
321 {
322 /* Same loop as hb_form_clusters().
323 * Since form_clusters() merged clusters already, we don't merge. */
324 unsigned int base = 0;
325 unsigned int count = buffer->len;
326 hb_glyph_info_t *info = buffer->info;
327 for (unsigned int i = 1; i < count; i++)
328 {
329 if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i]))))
330 {
331 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
332 buffer->merge_clusters (base, i);
333 buffer->reverse_range (base, i);
334
335 base = i;
336 }
337 }
338 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
339 buffer->merge_clusters (base, count);
340 buffer->reverse_range (base, count);
341
342 buffer->reverse ();
343
344 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
345 }
346 }
347
348
349 /* Substitute */
350
351 static inline void
352 hb_ot_mirror_chars (hb_ot_shape_context_t *c)
353 {
354 if (HB_DIRECTION_IS_FORWARD (c->target_direction))
355 return;
356
357 hb_buffer_t *buffer = c->buffer;
358 hb_unicode_funcs_t *unicode = buffer->unicode;
359 hb_mask_t rtlm_mask = c->plan->rtlm_mask;
360
361 unsigned int count = buffer->len;
362 hb_glyph_info_t *info = buffer->info;
363 for (unsigned int i = 0; i < count; i++) {
364 hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
365 if (likely (codepoint == info[i].codepoint || !c->font->has_glyph (codepoint)))
366 info[i].mask |= rtlm_mask;
367 else
368 info[i].codepoint = codepoint;
369 }
370 }
371
372 static inline void
373 hb_ot_shape_setup_masks_fraction (hb_ot_shape_context_t *c)
374 {
375 if (!(c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII) ||
376 !c->plan->has_frac)
377 return;
378
379 hb_buffer_t *buffer = c->buffer;
380
381 hb_mask_t pre_mask, post_mask;
382 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
383 {
384 pre_mask = c->plan->numr_mask | c->plan->frac_mask;
385 post_mask = c->plan->frac_mask | c->plan->dnom_mask;
386 }
387 else
388 {
389 pre_mask = c->plan->frac_mask | c->plan->dnom_mask;
390 post_mask = c->plan->numr_mask | c->plan->frac_mask;
391 }
392
393 unsigned int count = buffer->len;
394 hb_glyph_info_t *info = buffer->info;
395 for (unsigned int i = 0; i < count; i++)
396 {
397 if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
398 {
399 unsigned int start = i, end = i + 1;
400 while (start &&
401 _hb_glyph_info_get_general_category (&info[start - 1]) ==
402 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
403 start--;
404 while (end < count &&
405 _hb_glyph_info_get_general_category (&info[end]) ==
406 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
407 end++;
408
409 buffer->unsafe_to_break (start, end);
410
411 for (unsigned int j = start; j < i; j++)
412 info[j].mask |= pre_mask;
413 info[i].mask |= c->plan->frac_mask;
414 for (unsigned int j = i + 1; j < end; j++)
415 info[j].mask |= post_mask;
416
417 i = end - 1;
418 }
419 }
420 }
421
422 static inline void
423 hb_ot_shape_initialize_masks (hb_ot_shape_context_t *c)
424 {
425 hb_ot_map_t *map = &c->plan->map;
426 hb_buffer_t *buffer = c->buffer;
427
428 hb_mask_t global_mask = map->get_global_mask ();
429 buffer->reset_masks (global_mask);
430 }
431
432 static inline void
433 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
434 {
435 hb_ot_map_t *map = &c->plan->map;
436 hb_buffer_t *buffer = c->buffer;
437
438 hb_ot_shape_setup_masks_fraction (c);
439
440 if (c->plan->shaper->setup_masks)
441 c->plan->shaper->setup_masks (c->plan, buffer, c->font);
442
443 for (unsigned int i = 0; i < c->num_user_features; i++)
444 {
445 const hb_feature_t *feature = &c->user_features[i];
446 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
447 unsigned int shift;
448 hb_mask_t mask = map->get_mask (feature->tag, &shift);
449 buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
450 }
451 }
452 }
453
454 static void
455 hb_ot_zero_width_default_ignorables (hb_ot_shape_context_t *c)
456 {
457 hb_buffer_t *buffer = c->buffer;
458
459 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
460 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) ||
461 (buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES))
462 return;
463
464 unsigned int count = buffer->len;
465 hb_glyph_info_t *info = buffer->info;
466 hb_glyph_position_t *pos = buffer->pos;
467 unsigned int i = 0;
468 for (i = 0; i < count; i++)
469 if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
470 pos[i].x_advance = pos[i].y_advance = pos[i].x_offset = pos[i].y_offset = 0;
471 }
472
473 static void
474 hb_ot_hide_default_ignorables (hb_ot_shape_context_t *c)
475 {
476 hb_buffer_t *buffer = c->buffer;
477
478 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
479 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES))
480 return;
481
482 unsigned int count = buffer->len;
483 hb_glyph_info_t *info = buffer->info;
484 hb_glyph_position_t *pos = buffer->pos;
485 unsigned int i = 0;
486 for (i = 0; i < count; i++)
487 {
488 if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
489 break;
490 }
491
492 /* No default-ignorables found; return. */
493 if (i == count)
494 return;
495
496 hb_codepoint_t space;
497 if (!(buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES) &&
498 c->font->get_nominal_glyph (' ', &space))
499 {
500 /* Replace default-ignorables with a zero-advance space glyph. */
501 for (/*continue*/; i < count; i++)
502 {
503 if (_hb_glyph_info_is_default_ignorable (&info[i]))
504 info[i].codepoint = space;
505 }
506 }
507 else
508 {
509 /* Merge clusters and delete default-ignorables.
510 * NOTE! We can't use out-buffer as we have positioning data. */
511 unsigned int j = i;
512 for (; i < count; i++)
513 {
514 if (_hb_glyph_info_is_default_ignorable (&info[i]))
515 {
516 /* Merge clusters.
517 * Same logic as buffer->delete_glyph(), but for in-place removal. */
518
519 unsigned int cluster = info[i].cluster;
520 if (i + 1 < count && cluster == info[i + 1].cluster)
521 continue; /* Cluster survives; do nothing. */
522
523 if (j)
524 {
525 /* Merge cluster backward. */
526 if (cluster < info[j - 1].cluster)
527 {
528 unsigned int mask = info[i].mask;
529 unsigned int old_cluster = info[j - 1].cluster;
530 for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
531 buffer->set_cluster (info[k - 1], cluster, mask);
532 }
533 continue;
534 }
535
536 if (i + 1 < count)
537 buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */
538
539 continue;
540 }
541
542 if (j != i)
543 {
544 info[j] = info[i];
545 pos[j] = pos[i];
546 }
547 j++;
548 }
549 buffer->len = j;
550 }
551 }
552
553
554 static inline void
555 hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
556 {
557 /* Normalization process sets up glyph_index(), we just copy it. */
558 unsigned int count = buffer->len;
559 hb_glyph_info_t *info = buffer->info;
560 for (unsigned int i = 0; i < count; i++)
561 info[i].codepoint = info[i].glyph_index();
562
563 buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
564 }
565
566 static inline void
567 hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
568 {
569 unsigned int count = c->buffer->len;
570 hb_glyph_info_t *info = c->buffer->info;
571 for (unsigned int i = 0; i < count; i++)
572 {
573 hb_ot_layout_glyph_props_flags_t klass;
574
575 /* Never mark default-ignorables as marks.
576 * They won't get in the way of lookups anyway,
577 * but having them as mark will cause them to be skipped
578 * over if the lookup-flag says so, but at least for the
579 * Mongolian variation selectors, looks like Uniscribe
580 * marks them as non-mark. Some Mongolian fonts without
581 * GDEF rely on this. Another notable character that
582 * this applies to is COMBINING GRAPHEME JOINER. */
583 klass = (_hb_glyph_info_get_general_category (&info[i]) !=
584 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
585 _hb_glyph_info_is_default_ignorable (&info[i])) ?
586 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
587 HB_OT_LAYOUT_GLYPH_PROPS_MARK;
588 _hb_glyph_info_set_glyph_props (&info[i], klass);
589 }
590 }
591
592 static inline void
593 hb_ot_substitute_default (hb_ot_shape_context_t *c)
594 {
595 hb_buffer_t *buffer = c->buffer;
596
597 hb_ot_mirror_chars (c);
598
599 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
600
601 _hb_ot_shape_normalize (c->plan, buffer, c->font);
602
603 hb_ot_shape_setup_masks (c);
604
605 /* This is unfortunate to go here, but necessary... */
606 if (c->fallback_positioning)
607 _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, buffer);
608
609 hb_ot_map_glyphs_fast (buffer);
610
611 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
612 }
613
614 static inline void
615 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
616 {
617 hb_buffer_t *buffer = c->buffer;
618
619 hb_ot_layout_substitute_start (c->font, buffer);
620
621 if (!hb_ot_layout_has_glyph_classes (c->face))
622 hb_synthesize_glyph_classes (c);
623
624 c->plan->substitute (c->font, buffer);
625
626 /* XXX Call morx instead. */
627 //hb_aat_layout_substitute (c->font, c->buffer);
628 }
629
630 static inline void
631 hb_ot_substitute (hb_ot_shape_context_t *c)
632 {
633 hb_ot_substitute_default (c);
634
635 _hb_buffer_allocate_gsubgpos_vars (c->buffer);
636
637 hb_ot_substitute_complex (c);
638 }
639
640 /* Position */
641
642 static inline void
643 adjust_mark_offsets (hb_glyph_position_t *pos)
644 {
645 pos->x_offset -= pos->x_advance;
646 pos->y_offset -= pos->y_advance;
647 }
648
649 static inline void
650 zero_mark_width (hb_glyph_position_t *pos)
651 {
652 pos->x_advance = 0;
653 pos->y_advance = 0;
654 }
655
656 static inline void
657 zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
658 {
659 unsigned int count = buffer->len;
660 hb_glyph_info_t *info = buffer->info;
661 for (unsigned int i = 0; i < count; i++)
662 if (_hb_glyph_info_is_mark (&info[i]))
663 {
664 if (adjust_offsets)
665 adjust_mark_offsets (&buffer->pos[i]);
666 zero_mark_width (&buffer->pos[i]);
667 }
668 }
669
670 static inline void
671 hb_ot_position_default (hb_ot_shape_context_t *c)
672 {
673 hb_direction_t direction = c->buffer->props.direction;
674 unsigned int count = c->buffer->len;
675 hb_glyph_info_t *info = c->buffer->info;
676 hb_glyph_position_t *pos = c->buffer->pos;
677
678 if (HB_DIRECTION_IS_HORIZONTAL (direction))
679 {
680 for (unsigned int i = 0; i < count; i++)
681 pos[i].x_advance = c->font->get_glyph_h_advance (info[i].codepoint);
682 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
683 if (c->font->has_glyph_h_origin_func ())
684 for (unsigned int i = 0; i < count; i++)
685 c->font->subtract_glyph_h_origin (info[i].codepoint,
686 &pos[i].x_offset,
687 &pos[i].y_offset);
688 }
689 else
690 {
691 for (unsigned int i = 0; i < count; i++)
692 {
693 pos[i].y_advance = c->font->get_glyph_v_advance (info[i].codepoint);
694 c->font->subtract_glyph_v_origin (info[i].codepoint,
695 &pos[i].x_offset,
696 &pos[i].y_offset);
697 }
698 }
699 if (c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK)
700 _hb_ot_shape_fallback_spaces (c->plan, c->font, c->buffer);
701 }
702
703 static inline void
704 hb_ot_position_complex (hb_ot_shape_context_t *c)
705 {
706 unsigned int count = c->buffer->len;
707 hb_glyph_info_t *info = c->buffer->info;
708 hb_glyph_position_t *pos = c->buffer->pos;
709
710 /* If the font has no GPOS, AND, no fallback positioning will
711 * happen, AND, direction is forward, then when zeroing mark
712 * widths, we shift the mark with it, such that the mark
713 * is positioned hanging over the previous glyph. When
714 * direction is backward we don't shift and it will end up
715 * hanging over the next glyph after the final reordering.
716 * If fallback positinoing happens or GPOS is present, we don't
717 * care.
718 */
719 bool adjust_offsets_when_zeroing = c->fallback_positioning &&
720 !c->plan->shaper->fallback_position &&
721 HB_DIRECTION_IS_FORWARD (c->buffer->props.direction);
722
723 /* We change glyph origin to what GPOS expects (horizontal), apply GPOS, change it back. */
724
725 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
726 if (c->font->has_glyph_h_origin_func ())
727 for (unsigned int i = 0; i < count; i++)
728 c->font->add_glyph_h_origin (info[i].codepoint,
729 &pos[i].x_offset,
730 &pos[i].y_offset);
731
732 hb_ot_layout_position_start (c->font, c->buffer);
733
734 switch (c->plan->shaper->zero_width_marks)
735 {
736 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
737 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
738 break;
739
740 default:
741 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
742 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
743 break;
744 }
745
746 if (likely (!c->fallback_positioning))
747 c->plan->position (c->font, c->buffer);
748
749 switch (c->plan->shaper->zero_width_marks)
750 {
751 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
752 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
753 break;
754
755 default:
756 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
757 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
758 break;
759 }
760
761 /* Finishing off GPOS has to follow a certain order. */
762 hb_ot_layout_position_finish_advances (c->font, c->buffer);
763 hb_ot_zero_width_default_ignorables (c);
764 hb_ot_layout_position_finish_offsets (c->font, c->buffer);
765
766 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
767 if (c->font->has_glyph_h_origin_func ())
768 for (unsigned int i = 0; i < count; i++)
769 c->font->subtract_glyph_h_origin (info[i].codepoint,
770 &pos[i].x_offset,
771 &pos[i].y_offset);
772 }
773
774 static inline void
775 hb_ot_position (hb_ot_shape_context_t *c)
776 {
777 c->buffer->clear_positions ();
778
779 hb_ot_position_default (c);
780
781 hb_ot_position_complex (c);
782
783 if (c->fallback_positioning && c->plan->shaper->fallback_position)
784 _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer);
785
786 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
787 hb_buffer_reverse (c->buffer);
788
789 /* Visual fallback goes here. */
790
791 if (c->fallback_positioning)
792 _hb_ot_shape_fallback_kern (c->plan, c->font, c->buffer);
793
794 _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
795
796 //hb_aat_layout_position (c->font, c->buffer);
797 }
798
799 static inline void
800 hb_propagate_flags (hb_buffer_t *buffer)
801 {
802 /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
803 * Simplifies using them. */
804
805 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK))
806 return;
807
808 hb_glyph_info_t *info = buffer->info;
809
810 foreach_cluster (buffer, start, end)
811 {
812 unsigned int mask = 0;
813 for (unsigned int i = start; i < end; i++)
814 if (info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
815 {
816 mask = HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
817 break;
818 }
819 if (mask)
820 for (unsigned int i = start; i < end; i++)
821 info[i].mask |= mask;
822 }
823 }
824
825 /* Pull it all together! */
826
827 static void
828 hb_ot_shape_internal (hb_ot_shape_context_t *c)
829 {
830 c->buffer->deallocate_var_all ();
831 c->buffer->scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
832 if (likely (!_hb_unsigned_int_mul_overflows (c->buffer->len, HB_BUFFER_MAX_LEN_FACTOR)))
833 {
834 c->buffer->max_len = MAX (c->buffer->len * HB_BUFFER_MAX_LEN_FACTOR,
835 (unsigned) HB_BUFFER_MAX_LEN_MIN);
836 }
837 if (likely (!_hb_unsigned_int_mul_overflows (c->buffer->len, HB_BUFFER_MAX_OPS_FACTOR)))
838 {
839 c->buffer->max_ops = MAX (c->buffer->len * HB_BUFFER_MAX_OPS_FACTOR,
840 (unsigned) HB_BUFFER_MAX_OPS_MIN);
841 }
842
843 bool disable_otl = c->plan->shaper->disable_otl && c->plan->shaper->disable_otl (c->plan);
844 //c->fallback_substitute = disable_otl || !hb_ot_layout_has_substitution (c->face);
845 c->fallback_positioning = disable_otl || !hb_ot_layout_has_positioning (c->face);
846 c->fallback_glyph_classes = disable_otl || !hb_ot_layout_has_glyph_classes (c->face);
847
848 /* Save the original direction, we use it later. */
849 c->target_direction = c->buffer->props.direction;
850
851 _hb_buffer_allocate_unicode_vars (c->buffer);
852
853 c->buffer->clear_output ();
854
855 hb_ot_shape_initialize_masks (c);
856 hb_set_unicode_props (c->buffer);
857 hb_insert_dotted_circle (c->buffer, c->font);
858
859 hb_form_clusters (c->buffer);
860
861 hb_ensure_native_direction (c->buffer);
862
863 if (c->plan->shaper->preprocess_text)
864 c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
865
866 hb_ot_substitute (c);
867 hb_ot_position (c);
868
869 hb_ot_hide_default_ignorables (c);
870
871 if (c->plan->shaper->postprocess_glyphs)
872 c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
873
874 hb_propagate_flags (c->buffer);
875
876 _hb_buffer_deallocate_unicode_vars (c->buffer);
877
878 c->buffer->props.direction = c->target_direction;
879
880 c->buffer->max_len = HB_BUFFER_MAX_LEN_DEFAULT;
881 c->buffer->max_ops = HB_BUFFER_MAX_OPS_DEFAULT;
882 c->buffer->deallocate_var_all ();
883 }
884
885
886 hb_bool_t
887 _hb_ot_shape (hb_shape_plan_t *shape_plan,
888 hb_font_t *font,
889 hb_buffer_t *buffer,
890 const hb_feature_t *features,
891 unsigned int num_features)
892 {
893 hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features};
894 hb_ot_shape_internal (&c);
895
896 return true;
897 }
898
899
900 /**
901 * hb_ot_shape_plan_collect_lookups:
902 *
903 * Since: 0.9.7
904 **/
905 void
906 hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
907 hb_tag_t table_tag,
908 hb_set_t *lookup_indexes /* OUT */)
909 {
910 /* XXX Does the first part always succeed? */
911 HB_SHAPER_DATA_GET (shape_plan)->collect_lookups (table_tag, lookup_indexes);
912 }
913
914
915 /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
916 static void
917 add_char (hb_font_t *font,
918 hb_unicode_funcs_t *unicode,
919 hb_bool_t mirror,
920 hb_codepoint_t u,
921 hb_set_t *glyphs)
922 {
923 hb_codepoint_t glyph;
924 if (font->get_nominal_glyph (u, &glyph))
925 glyphs->add (glyph);
926 if (mirror)
927 {
928 hb_codepoint_t m = unicode->mirroring (u);
929 if (m != u && font->get_nominal_glyph (m, &glyph))
930 glyphs->add (glyph);
931 }
932 }
933
934
935 /**
936 * hb_ot_shape_glyphs_closure:
937 *
938 * Since: 0.9.2
939 **/
940 void
941 hb_ot_shape_glyphs_closure (hb_font_t *font,
942 hb_buffer_t *buffer,
943 const hb_feature_t *features,
944 unsigned int num_features,
945 hb_set_t *glyphs)
946 {
947 const char *shapers[] = {"ot", nullptr};
948 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
949 features, num_features, shapers);
950
951 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
952
953 unsigned int count = buffer->len;
954 hb_glyph_info_t *info = buffer->info;
955 for (unsigned int i = 0; i < count; i++)
956 add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
957
958 hb_set_t *lookups = hb_set_create ();
959 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, lookups);
960 hb_ot_layout_lookups_substitute_closure (font->face, lookups, glyphs);
961
962 hb_set_destroy (lookups);
963
964 hb_shape_plan_destroy (shape_plan);
965 }