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#include "hb-shaper-impl.hh"
30
31#include "hb-ot-shape.hh"
32#include "hb-ot-shape-complex.hh"
33#include "hb-ot-shape-fallback.hh"
34#include "hb-ot-shape-normalize.hh"
35
36#include "hb-ot-face.hh"
37
38#include "hb-set.hh"
39
40#include "hb-aat-layout.hh"
41
42
43/**
44 * SECTION:hb-ot-shape
45 * @title: hb-ot-shape
46 * @short_description: OpenType shaping support
47 * @include: hb-ot.h
48 *
49 * Support functions for OpenType shaping related queries.
50 **/
51
52
53static void
54hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
55 const hb_feature_t *user_features,
56 unsigned int num_user_features);
57
58static bool
59_hb_apply_morx (hb_face_t *face)
60{
61 if (hb_options ().aat &&
62 hb_aat_layout_has_substitution (face))
63 return true;
64
65 /* Ignore empty GSUB tables. */
66 return (!hb_ot_layout_has_substitution (face) ||
67 !hb_ot_layout_table_get_script_tags (face,
68 HB_OT_TAG_GSUB,
69 0, nullptr, nullptr)) &&
70 hb_aat_layout_has_substitution (face);
71}
72
73hb_ot_shape_planner_t::hb_ot_shape_planner_t (hb_face_t *face,
74 const hb_segment_properties_t *props) :
75 face (face),
76 props (*props),
77 map (face, props),
78 aat_map (face, props),
79 apply_morx (_hb_apply_morx (face))
80{
81 shaper = hb_ot_shape_complex_categorize (this);
82
83 script_zero_marks = shaper->zero_width_marks != HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE;
84 script_fallback_mark_positioning = shaper->fallback_position;
85
86 if (apply_morx)
87 shaper = &_hb_ot_complex_shaper_default;
88}
89
90void
91hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t &plan,
92 const hb_ot_shape_plan_key_t &key)
93{
94 plan.props = props;
95 plan.shaper = shaper;
96 map.compile (plan.map, key);
97 if (apply_morx)
98 aat_map.compile (plan.aat_map);
99
100 plan.frac_mask = plan.map.get_1_mask (HB_TAG ('f','r','a','c'));
101 plan.numr_mask = plan.map.get_1_mask (HB_TAG ('n','u','m','r'));
102 plan.dnom_mask = plan.map.get_1_mask (HB_TAG ('d','n','o','m'));
103 plan.has_frac = plan.frac_mask || (plan.numr_mask && plan.dnom_mask);
104 plan.rtlm_mask = plan.map.get_1_mask (HB_TAG ('r','t','l','m'));
105 hb_tag_t kern_tag = HB_DIRECTION_IS_HORIZONTAL (props.direction) ?
106 HB_TAG ('k','e','r','n') : HB_TAG ('v','k','r','n');
107 plan.kern_mask = plan.map.get_mask (kern_tag);
108 plan.trak_mask = plan.map.get_mask (HB_TAG ('t','r','a','k'));
109
110 plan.requested_kerning = !!plan.kern_mask;
111 plan.requested_tracking = !!plan.trak_mask;
112 bool has_gpos_kern = plan.map.get_feature_index (1, kern_tag) != HB_OT_LAYOUT_NO_FEATURE_INDEX;
113 bool disable_gpos = plan.shaper->gpos_tag &&
114 plan.shaper->gpos_tag != plan.map.chosen_script[1];
115
116 /*
117 * Decide who provides glyph classes. GDEF or Unicode.
118 */
119
120 if (!hb_ot_layout_has_glyph_classes (face))
121 plan.fallback_glyph_classes = true;
122
123 /*
124 * Decide who does substitutions. GSUB, morx, or fallback.
125 */
126
127 plan.apply_morx = apply_morx;
128
129 /*
130 * Decide who does positioning. GPOS, kerx, kern, or fallback.
131 */
132
133 if (hb_options ().aat && hb_aat_layout_has_positioning (face))
134 plan.apply_kerx = true;
135 else if (!apply_morx && !disable_gpos && hb_ot_layout_has_positioning (face))
136 plan.apply_gpos = true;
137 else if (hb_aat_layout_has_positioning (face))
138 plan.apply_kerx = true;
139
140 if (!plan.apply_kerx && !has_gpos_kern)
141 {
142 /* Apparently Apple applies kerx if GPOS kern was not applied. */
143 if (hb_aat_layout_has_positioning (face))
144 plan.apply_kerx = true;
145 else if (hb_ot_layout_has_kerning (face))
146 plan.apply_kern = true;
147 }
148
149 plan.zero_marks = script_zero_marks &&
150 !plan.apply_kerx &&
151 (!plan.apply_kern || !hb_ot_layout_has_machine_kerning (face));
152 plan.has_gpos_mark = !!plan.map.get_1_mask (HB_TAG ('m','a','r','k'));
153
154 plan.adjust_mark_positioning_when_zeroing = !plan.apply_gpos &&
155 !plan.apply_kerx &&
156 (!plan.apply_kern || !hb_ot_layout_has_cross_kerning (face));
157
158 plan.fallback_mark_positioning = plan.adjust_mark_positioning_when_zeroing &&
159 script_fallback_mark_positioning;
160
161 /* Currently we always apply trak. */
162 plan.apply_trak = plan.requested_tracking && hb_aat_layout_has_tracking (face);
163}
164
165bool
166hb_ot_shape_plan_t::init0 (hb_face_t *face,
167 const hb_shape_plan_key_t *key)
168{
169 map.init ();
170 aat_map.init ();
171
172 hb_ot_shape_planner_t planner (face,
173 &key->props);
174
175 hb_ot_shape_collect_features (&planner,
176 key->user_features,
177 key->num_user_features);
178
179 planner.compile (*this, key->ot);
180
181 if (shaper->data_create)
182 {
183 data = shaper->data_create (this);
184 if (unlikely (!data))
185 return false;
186 }
187
188 return true;
189}
190
191void
192hb_ot_shape_plan_t::fini ()
193{
194 if (shaper->data_destroy)
195 shaper->data_destroy (const_cast<void *> (data));
196
197 map.fini ();
198 aat_map.fini ();
199}
200
201void
202hb_ot_shape_plan_t::substitute (hb_font_t *font,
203 hb_buffer_t *buffer) const
204{
205 if (unlikely (apply_morx))
206 hb_aat_layout_substitute (this, font, buffer);
207 else
208 map.substitute (this, font, buffer);
209}
210
211void
212hb_ot_shape_plan_t::position (hb_font_t *font,
213 hb_buffer_t *buffer) const
214{
215 if (this->apply_gpos)
216 map.position (this, font, buffer);
217 else if (this->apply_kerx)
218 hb_aat_layout_position (this, font, buffer);
219 else if (this->apply_kern)
220 hb_ot_layout_kern (this, font, buffer);
221 else
222 _hb_ot_shape_fallback_kern (this, font, buffer);
223
224 if (this->apply_trak)
225 hb_aat_layout_track (this, font, buffer);
226}
227
228
229static const hb_ot_map_feature_t
230common_features[] =
231{
232 {HB_TAG('c','c','m','p'), F_GLOBAL},
233 {HB_TAG('l','o','c','l'), F_GLOBAL},
234 {HB_TAG('m','a','r','k'), F_GLOBAL_MANUAL_JOINERS},
235 {HB_TAG('m','k','m','k'), F_GLOBAL_MANUAL_JOINERS},
236 {HB_TAG('r','l','i','g'), F_GLOBAL},
237};
238
239
240static const hb_ot_map_feature_t
241horizontal_features[] =
242{
243 {HB_TAG('c','a','l','t'), F_GLOBAL},
244 {HB_TAG('c','l','i','g'), F_GLOBAL},
245 {HB_TAG('c','u','r','s'), F_GLOBAL},
246 {HB_TAG('k','e','r','n'), F_GLOBAL_HAS_FALLBACK},
247 {HB_TAG('l','i','g','a'), F_GLOBAL},
248 {HB_TAG('r','c','l','t'), F_GLOBAL},
249};
250
251static void
252hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
253 const hb_feature_t *user_features,
254 unsigned int num_user_features)
255{
256 hb_ot_map_builder_t *map = &planner->map;
257
258 map->enable_feature (HB_TAG('r','v','r','n'));
259 map->add_gsub_pause (nullptr);
260
261 switch (planner->props.direction) {
262 case HB_DIRECTION_LTR:
263 map->enable_feature (HB_TAG ('l','t','r','a'));
264 map->enable_feature (HB_TAG ('l','t','r','m'));
265 break;
266 case HB_DIRECTION_RTL:
267 map->enable_feature (HB_TAG ('r','t','l','a'));
268 map->add_feature (HB_TAG ('r','t','l','m'));
269 break;
270 case HB_DIRECTION_TTB:
271 case HB_DIRECTION_BTT:
272 case HB_DIRECTION_INVALID:
273 default:
274 break;
275 }
276
277 /* Automatic fractions. */
278 map->add_feature (HB_TAG ('f','r','a','c'));
279 map->add_feature (HB_TAG ('n','u','m','r'));
280 map->add_feature (HB_TAG ('d','n','o','m'));
281
282 /* Random! */
283 map->enable_feature (HB_TAG ('r','a','n','d'), F_RANDOM, HB_OT_MAP_MAX_VALUE);
284
285 /* Tracking. We enable dummy feature here just to allow disabling
286 * AAT 'trak' table using features.
287 * https://github.com/harfbuzz/harfbuzz/issues/1303 */
288 map->enable_feature (HB_TAG ('t','r','a','k'), F_HAS_FALLBACK);
289
290 map->enable_feature (HB_TAG ('H','A','R','F'));
291
292 if (planner->shaper->collect_features)
293 planner->shaper->collect_features (planner);
294
295 map->enable_feature (HB_TAG ('B','U','Z','Z'));
296
297 for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
298 map->add_feature (common_features[i]);
299
300 if (HB_DIRECTION_IS_HORIZONTAL (planner->props.direction))
301 for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
302 map->add_feature (horizontal_features[i]);
303 else
304 {
305 /* We really want to find a 'vert' feature if there's any in the font, no
306 * matter which script/langsys it is listed (or not) under.
307 * See various bugs referenced from:
308 * https://github.com/harfbuzz/harfbuzz/issues/63 */
309 map->enable_feature (HB_TAG ('v','e','r','t'), F_GLOBAL_SEARCH);
310 }
311
312 for (unsigned int i = 0; i < num_user_features; i++)
313 {
314 const hb_feature_t *feature = &user_features[i];
315 map->add_feature (feature->tag,
316 (feature->start == HB_FEATURE_GLOBAL_START &&
317 feature->end == HB_FEATURE_GLOBAL_END) ? F_GLOBAL : F_NONE,
318 feature->value);
319 }
320
321 if (planner->apply_morx)
322 {
323 hb_aat_map_builder_t *aat_map = &planner->aat_map;
324 for (unsigned int i = 0; i < num_user_features; i++)
325 {
326 const hb_feature_t *feature = &user_features[i];
327 aat_map->add_feature (feature->tag, feature->value);
328 }
329 }
330
331 if (planner->shaper->override_features)
332 planner->shaper->override_features (planner);
333}
334
335
336/*
337 * shaper face data
338 */
339
340struct hb_ot_face_data_t {};
341
342hb_ot_face_data_t *
343_hb_ot_shaper_face_data_create (hb_face_t *face)
344{
345 return (hb_ot_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
346}
347
348void
349_hb_ot_shaper_face_data_destroy (hb_ot_face_data_t *data)
350{
351}
352
353
354/*
355 * shaper font data
356 */
357
358struct hb_ot_font_data_t {};
359
360hb_ot_font_data_t *
361_hb_ot_shaper_font_data_create (hb_font_t *font HB_UNUSED)
362{
363 return (hb_ot_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
364}
365
366void
367_hb_ot_shaper_font_data_destroy (hb_ot_font_data_t *data HB_UNUSED)
368{
369}
370
371
372/*
373 * shaper
374 */
375
376struct hb_ot_shape_context_t
377{
378 hb_ot_shape_plan_t *plan;
379 hb_font_t *font;
380 hb_face_t *face;
381 hb_buffer_t *buffer;
382 const hb_feature_t *user_features;
383 unsigned int num_user_features;
384
385 /* Transient stuff */
386 hb_direction_t target_direction;
387};
388
389
390
391/* Main shaper */
392
393
394/* Prepare */
395
396static void
397hb_set_unicode_props (hb_buffer_t *buffer)
398{
399 /* Implement enough of Unicode Graphemes here that shaping
400 * in reverse-direction wouldn't break graphemes. Namely,
401 * we mark all marks and ZWJ and ZWJ,Extended_Pictographic
402 * sequences as continuations. The foreach_grapheme()
403 * macro uses this bit.
404 *
405 * https://www.unicode.org/reports/tr29/#Regex_Definitions
406 */
407 unsigned int count = buffer->len;
408 hb_glyph_info_t *info = buffer->info;
409 for (unsigned int i = 0; i < count; i++)
410 {
411 _hb_glyph_info_set_unicode_props (&info[i], buffer);
412
413 /* Marks are already set as continuation by the above line.
414 * Handle Emoji_Modifier and ZWJ-continuation. */
415 if (unlikely (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL &&
416 hb_in_range<hb_codepoint_t> (info[i].codepoint, 0x1F3FBu, 0x1F3FFu)))
417 {
418 _hb_glyph_info_set_continuation (&info[i]);
419 }
420 else if (unlikely (_hb_glyph_info_is_zwj (&info[i])))
421 {
422 _hb_glyph_info_set_continuation (&info[i]);
423 if (i + 1 < count &&
424 _hb_unicode_is_emoji_Extended_Pictographic (info[i + 1].codepoint))
425 {
426 i++;
427 _hb_glyph_info_set_unicode_props (&info[i], buffer);
428 _hb_glyph_info_set_continuation (&info[i]);
429 }
430 }
431 /* Or part of the Other_Grapheme_Extend that is not marks.
432 * As of Unicode 11 that is just:
433 *
434 * 200C ; Other_Grapheme_Extend # Cf ZERO WIDTH NON-JOINER
435 * FF9E..FF9F ; Other_Grapheme_Extend # Lm [2] HALFWIDTH KATAKANA VOICED SOUND MARK..HALFWIDTH KATAKANA SEMI-VOICED SOUND MARK
436 * E0020..E007F ; Other_Grapheme_Extend # Cf [96] TAG SPACE..CANCEL TAG
437 *
438 * ZWNJ is special, we don't want to merge it as there's no need, and keeping
439 * it separate results in more granular clusters. Ignore Katakana for now.
440 * Tags are used for Emoji sub-region flag sequences:
441 * https://github.com/harfbuzz/harfbuzz/issues/1556
442 */
443 else if (unlikely (hb_in_range<hb_codepoint_t> (info[i].codepoint, 0xE0020u, 0xE007Fu)))
444 _hb_glyph_info_set_continuation (&info[i]);
445 }
446}
447
448static void
449hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
450{
451 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
452 buffer->context_len[0] ||
453 !_hb_glyph_info_is_unicode_mark (&buffer->info[0]))
454 return;
455
456 if (!font->has_glyph (0x25CCu))
457 return;
458
459 hb_glyph_info_t dottedcircle = {0};
460 dottedcircle.codepoint = 0x25CCu;
461 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer);
462
463 buffer->clear_output ();
464
465 buffer->idx = 0;
466 hb_glyph_info_t info = dottedcircle;
467 info.cluster = buffer->cur().cluster;
468 info.mask = buffer->cur().mask;
469 buffer->output_info (info);
470 while (buffer->idx < buffer->len && buffer->successful)
471 buffer->next_glyph ();
472 buffer->swap_buffers ();
473}
474
475static void
476hb_form_clusters (hb_buffer_t *buffer)
477{
478 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII))
479 return;
480
481 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
482 foreach_grapheme (buffer, start, end)
483 buffer->merge_clusters (start, end);
484 else
485 foreach_grapheme (buffer, start, end)
486 buffer->unsafe_to_break (start, end);
487}
488
489static void
490hb_ensure_native_direction (hb_buffer_t *buffer)
491{
492 hb_direction_t direction = buffer->props.direction;
493 hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
494
495 /* TODO vertical:
496 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
497 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
498 * first. */
499 if ((HB_DIRECTION_IS_HORIZONTAL (direction) &&
500 direction != horiz_dir && horiz_dir != HB_DIRECTION_INVALID) ||
501 (HB_DIRECTION_IS_VERTICAL (direction) &&
502 direction != HB_DIRECTION_TTB))
503 {
504
505 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
506 foreach_grapheme (buffer, start, end)
507 {
508 buffer->merge_clusters (start, end);
509 buffer->reverse_range (start, end);
510 }
511 else
512 foreach_grapheme (buffer, start, end)
513 /* form_clusters() merged clusters already, we don't merge. */
514 buffer->reverse_range (start, end);
515
516 buffer->reverse ();
517
518 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
519 }
520}
521
522
523/*
524 * Substitute
525 */
526
527static inline void
528hb_ot_mirror_chars (const hb_ot_shape_context_t *c)
529{
530 if (HB_DIRECTION_IS_FORWARD (c->target_direction))
531 return;
532
533 hb_buffer_t *buffer = c->buffer;
534 hb_unicode_funcs_t *unicode = buffer->unicode;
535 hb_mask_t rtlm_mask = c->plan->rtlm_mask;
536
537 unsigned int count = buffer->len;
538 hb_glyph_info_t *info = buffer->info;
539 for (unsigned int i = 0; i < count; i++) {
540 hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
541 if (likely (codepoint == info[i].codepoint || !c->font->has_glyph (codepoint)))
542 info[i].mask |= rtlm_mask;
543 else
544 info[i].codepoint = codepoint;
545 }
546}
547
548static inline void
549hb_ot_shape_setup_masks_fraction (const hb_ot_shape_context_t *c)
550{
551 if (!(c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII) ||
552 !c->plan->has_frac)
553 return;
554
555 hb_buffer_t *buffer = c->buffer;
556
557 hb_mask_t pre_mask, post_mask;
558 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
559 {
560 pre_mask = c->plan->numr_mask | c->plan->frac_mask;
561 post_mask = c->plan->frac_mask | c->plan->dnom_mask;
562 }
563 else
564 {
565 pre_mask = c->plan->frac_mask | c->plan->dnom_mask;
566 post_mask = c->plan->numr_mask | c->plan->frac_mask;
567 }
568
569 unsigned int count = buffer->len;
570 hb_glyph_info_t *info = buffer->info;
571 for (unsigned int i = 0; i < count; i++)
572 {
573 if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
574 {
575 unsigned int start = i, end = i + 1;
576 while (start &&
577 _hb_glyph_info_get_general_category (&info[start - 1]) ==
578 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
579 start--;
580 while (end < count &&
581 _hb_glyph_info_get_general_category (&info[end]) ==
582 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
583 end++;
584
585 buffer->unsafe_to_break (start, end);
586
587 for (unsigned int j = start; j < i; j++)
588 info[j].mask |= pre_mask;
589 info[i].mask |= c->plan->frac_mask;
590 for (unsigned int j = i + 1; j < end; j++)
591 info[j].mask |= post_mask;
592
593 i = end - 1;
594 }
595 }
596}
597
598static inline void
599hb_ot_shape_initialize_masks (const hb_ot_shape_context_t *c)
600{
601 hb_ot_map_t *map = &c->plan->map;
602 hb_buffer_t *buffer = c->buffer;
603
604 hb_mask_t global_mask = map->get_global_mask ();
605 buffer->reset_masks (global_mask);
606}
607
608static inline void
609hb_ot_shape_setup_masks (const hb_ot_shape_context_t *c)
610{
611 hb_ot_map_t *map = &c->plan->map;
612 hb_buffer_t *buffer = c->buffer;
613
614 hb_ot_shape_setup_masks_fraction (c);
615
616 if (c->plan->shaper->setup_masks)
617 c->plan->shaper->setup_masks (c->plan, buffer, c->font);
618
619 for (unsigned int i = 0; i < c->num_user_features; i++)
620 {
621 const hb_feature_t *feature = &c->user_features[i];
622 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
623 unsigned int shift;
624 hb_mask_t mask = map->get_mask (feature->tag, &shift);
625 buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
626 }
627 }
628}
629
630static void
631hb_ot_zero_width_default_ignorables (const hb_buffer_t *buffer)
632{
633 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
634 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) ||
635 (buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES))
636 return;
637
638 unsigned int count = buffer->len;
639 hb_glyph_info_t *info = buffer->info;
640 hb_glyph_position_t *pos = buffer->pos;
641 unsigned int i = 0;
642 for (i = 0; i < count; i++)
643 if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
644 pos[i].x_advance = pos[i].y_advance = pos[i].x_offset = pos[i].y_offset = 0;
645}
646
647static void
648hb_ot_hide_default_ignorables (hb_buffer_t *buffer,
649 hb_font_t *font)
650{
651 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
652 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES))
653 return;
654
655 unsigned int count = buffer->len;
656 hb_glyph_info_t *info = buffer->info;
657
658 hb_codepoint_t invisible = buffer->invisible;
659 if (!(buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES) &&
660 (invisible || font->get_nominal_glyph (' ', &invisible)))
661 {
662 /* Replace default-ignorables with a zero-advance invisible glyph. */
663 for (unsigned int i = 0; i < count; i++)
664 {
665 if (_hb_glyph_info_is_default_ignorable (&info[i]))
666 info[i].codepoint = invisible;
667 }
668 }
669 else
670 hb_ot_layout_delete_glyphs_inplace (buffer, _hb_glyph_info_is_default_ignorable);
671}
672
673
674static inline void
675hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
676{
677 /* Normalization process sets up glyph_index(), we just copy it. */
678 unsigned int count = buffer->len;
679 hb_glyph_info_t *info = buffer->info;
680 for (unsigned int i = 0; i < count; i++)
681 info[i].codepoint = info[i].glyph_index();
682
683 buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
684}
685
686static inline void
687hb_synthesize_glyph_classes (hb_buffer_t *buffer)
688{
689 unsigned int count = buffer->len;
690 hb_glyph_info_t *info = buffer->info;
691 for (unsigned int i = 0; i < count; i++)
692 {
693 hb_ot_layout_glyph_props_flags_t klass;
694
695 /* Never mark default-ignorables as marks.
696 * They won't get in the way of lookups anyway,
697 * but having them as mark will cause them to be skipped
698 * over if the lookup-flag says so, but at least for the
699 * Mongolian variation selectors, looks like Uniscribe
700 * marks them as non-mark. Some Mongolian fonts without
701 * GDEF rely on this. Another notable character that
702 * this applies to is COMBINING GRAPHEME JOINER. */
703 klass = (_hb_glyph_info_get_general_category (&info[i]) !=
704 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
705 _hb_glyph_info_is_default_ignorable (&info[i])) ?
706 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
707 HB_OT_LAYOUT_GLYPH_PROPS_MARK;
708 _hb_glyph_info_set_glyph_props (&info[i], klass);
709 }
710}
711
712static inline void
713hb_ot_substitute_default (const hb_ot_shape_context_t *c)
714{
715 hb_buffer_t *buffer = c->buffer;
716
717 hb_ot_mirror_chars (c);
718
719 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
720
721 _hb_ot_shape_normalize (c->plan, buffer, c->font);
722
723 hb_ot_shape_setup_masks (c);
724
725 /* This is unfortunate to go here, but necessary... */
726 if (c->plan->fallback_mark_positioning)
727 _hb_ot_shape_fallback_mark_position_recategorize_marks (c->plan, c->font, buffer);
728
729 hb_ot_map_glyphs_fast (buffer);
730
731 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
732}
733
734static inline void
735hb_ot_substitute_complex (const hb_ot_shape_context_t *c)
736{
737 hb_buffer_t *buffer = c->buffer;
738
739 hb_ot_layout_substitute_start (c->font, buffer);
740
741 if (c->plan->fallback_glyph_classes)
742 hb_synthesize_glyph_classes (c->buffer);
743
744 c->plan->substitute (c->font, buffer);
745}
746
747static inline void
748hb_ot_substitute_pre (const hb_ot_shape_context_t *c)
749{
750 hb_ot_substitute_default (c);
751
752 _hb_buffer_allocate_gsubgpos_vars (c->buffer);
753
754 hb_ot_substitute_complex (c);
755}
756
757static inline void
758hb_ot_substitute_post (const hb_ot_shape_context_t *c)
759{
760 hb_ot_hide_default_ignorables (c->buffer, c->font);
761 if (c->plan->apply_morx)
762 hb_aat_layout_remove_deleted_glyphs (c->buffer);
763
764 if (c->plan->shaper->postprocess_glyphs)
765 c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
766}
767
768
769/*
770 * Position
771 */
772
773static inline void
774adjust_mark_offsets (hb_glyph_position_t *pos)
775{
776 pos->x_offset -= pos->x_advance;
777 pos->y_offset -= pos->y_advance;
778}
779
780static inline void
781zero_mark_width (hb_glyph_position_t *pos)
782{
783 pos->x_advance = 0;
784 pos->y_advance = 0;
785}
786
787static inline void
788zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
789{
790 unsigned int count = buffer->len;
791 hb_glyph_info_t *info = buffer->info;
792 for (unsigned int i = 0; i < count; i++)
793 if (_hb_glyph_info_is_mark (&info[i]))
794 {
795 if (adjust_offsets)
796 adjust_mark_offsets (&buffer->pos[i]);
797 zero_mark_width (&buffer->pos[i]);
798 }
799}
800
801static inline void
802hb_ot_position_default (const hb_ot_shape_context_t *c)
803{
804 hb_direction_t direction = c->buffer->props.direction;
805 unsigned int count = c->buffer->len;
806 hb_glyph_info_t *info = c->buffer->info;
807 hb_glyph_position_t *pos = c->buffer->pos;
808
809 if (HB_DIRECTION_IS_HORIZONTAL (direction))
810 {
811 c->font->get_glyph_h_advances (count, &info[0].codepoint, sizeof(info[0]),
812 &pos[0].x_advance, sizeof(pos[0]));
813 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
814 if (c->font->has_glyph_h_origin_func ())
815 for (unsigned int i = 0; i < count; i++)
816 c->font->subtract_glyph_h_origin (info[i].codepoint,
817 &pos[i].x_offset,
818 &pos[i].y_offset);
819 }
820 else
821 {
822 c->font->get_glyph_v_advances (count, &info[0].codepoint, sizeof(info[0]),
823 &pos[0].y_advance, sizeof(pos[0]));
824 for (unsigned int i = 0; i < count; i++)
825 {
826 c->font->subtract_glyph_v_origin (info[i].codepoint,
827 &pos[i].x_offset,
828 &pos[i].y_offset);
829 }
830 }
831 if (c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK)
832 _hb_ot_shape_fallback_spaces (c->plan, c->font, c->buffer);
833}
834
835static inline void
836hb_ot_position_complex (const hb_ot_shape_context_t *c)
837{
838 unsigned int count = c->buffer->len;
839 hb_glyph_info_t *info = c->buffer->info;
840 hb_glyph_position_t *pos = c->buffer->pos;
841
842 /* If the font has no GPOS and direction is forward, then when
843 * zeroing mark widths, we shift the mark with it, such that the
844 * mark is positioned hanging over the previous glyph. When
845 * direction is backward we don't shift and it will end up
846 * hanging over the next glyph after the final reordering.
847 *
848 * Note: If fallback positinoing happens, we don't care about
849 * this as it will be overriden.
850 */
851 bool adjust_offsets_when_zeroing = c->plan->adjust_mark_positioning_when_zeroing &&
852 HB_DIRECTION_IS_FORWARD (c->buffer->props.direction);
853
854 /* We change glyph origin to what GPOS expects (horizontal), apply GPOS, change it back. */
855
856 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
857 if (c->font->has_glyph_h_origin_func ())
858 for (unsigned int i = 0; i < count; i++)
859 c->font->add_glyph_h_origin (info[i].codepoint,
860 &pos[i].x_offset,
861 &pos[i].y_offset);
862
863 hb_ot_layout_position_start (c->font, c->buffer);
864
865 if (c->plan->zero_marks)
866 switch (c->plan->shaper->zero_width_marks)
867 {
868 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
869 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
870 break;
871
872 default:
873 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
874 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
875 break;
876 }
877
878 c->plan->position (c->font, c->buffer);
879
880 if (c->plan->zero_marks)
881 switch (c->plan->shaper->zero_width_marks)
882 {
883 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
884 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
885 break;
886
887 default:
888 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
889 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
890 break;
891 }
892
893 /* Finish off. Has to follow a certain order. */
894 hb_ot_layout_position_finish_advances (c->font, c->buffer);
895 hb_ot_zero_width_default_ignorables (c->buffer);
896 if (c->plan->apply_morx)
897 hb_aat_layout_zero_width_deleted_glyphs (c->buffer);
898 hb_ot_layout_position_finish_offsets (c->font, c->buffer);
899
900 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
901 if (c->font->has_glyph_h_origin_func ())
902 for (unsigned int i = 0; i < count; i++)
903 c->font->subtract_glyph_h_origin (info[i].codepoint,
904 &pos[i].x_offset,
905 &pos[i].y_offset);
906
907 if (c->plan->fallback_mark_positioning)
908 _hb_ot_shape_fallback_mark_position (c->plan, c->font, c->buffer,
909 adjust_offsets_when_zeroing);
910}
911
912static inline void
913hb_ot_position (const hb_ot_shape_context_t *c)
914{
915 c->buffer->clear_positions ();
916
917 hb_ot_position_default (c);
918
919 hb_ot_position_complex (c);
920
921 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
922 hb_buffer_reverse (c->buffer);
923
924 _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
925}
926
927static inline void
928hb_propagate_flags (hb_buffer_t *buffer)
929{
930 /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
931 * Simplifies using them. */
932
933 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK))
934 return;
935
936 hb_glyph_info_t *info = buffer->info;
937
938 foreach_cluster (buffer, start, end)
939 {
940 unsigned int mask = 0;
941 for (unsigned int i = start; i < end; i++)
942 if (info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
943 {
944 mask = HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
945 break;
946 }
947 if (mask)
948 for (unsigned int i = start; i < end; i++)
949 info[i].mask |= mask;
950 }
951}
952
953/* Pull it all together! */
954
955static void
956hb_ot_shape_internal (hb_ot_shape_context_t *c)
957{
958 c->buffer->deallocate_var_all ();
959 c->buffer->scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
960 if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_LEN_FACTOR)))
961 {
962 c->buffer->max_len = MAX (c->buffer->len * HB_BUFFER_MAX_LEN_FACTOR,
963 (unsigned) HB_BUFFER_MAX_LEN_MIN);
964 }
965 if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_OPS_FACTOR)))
966 {
967 c->buffer->max_ops = MAX (c->buffer->len * HB_BUFFER_MAX_OPS_FACTOR,
968 (unsigned) HB_BUFFER_MAX_OPS_MIN);
969 }
970
971 /* Save the original direction, we use it later. */
972 c->target_direction = c->buffer->props.direction;
973
974 _hb_buffer_allocate_unicode_vars (c->buffer);
975
976 c->buffer->clear_output ();
977
978 hb_ot_shape_initialize_masks (c);
979 hb_set_unicode_props (c->buffer);
980 hb_insert_dotted_circle (c->buffer, c->font);
981
982 hb_form_clusters (c->buffer);
983
984 hb_ensure_native_direction (c->buffer);
985
986 if (c->plan->shaper->preprocess_text)
987 c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
988
989 hb_ot_substitute_pre (c);
990 hb_ot_position (c);
991 hb_ot_substitute_post (c);
992
993 hb_propagate_flags (c->buffer);
994
995 _hb_buffer_deallocate_unicode_vars (c->buffer);
996
997 c->buffer->props.direction = c->target_direction;
998
999 c->buffer->max_len = HB_BUFFER_MAX_LEN_DEFAULT;
1000 c->buffer->max_ops = HB_BUFFER_MAX_OPS_DEFAULT;
1001 c->buffer->deallocate_var_all ();
1002}
1003
1004
1005hb_bool_t
1006_hb_ot_shape (hb_shape_plan_t *shape_plan,
1007 hb_font_t *font,
1008 hb_buffer_t *buffer,
1009 const hb_feature_t *features,
1010 unsigned int num_features)
1011{
1012 hb_ot_shape_context_t c = {&shape_plan->ot, font, font->face, buffer, features, num_features};
1013 hb_ot_shape_internal (&c);
1014
1015 return true;
1016}
1017
1018
1019/**
1020 * hb_ot_shape_plan_collect_lookups:
1021 *
1022 * Since: 0.9.7
1023 **/
1024void
1025hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
1026 hb_tag_t table_tag,
1027 hb_set_t *lookup_indexes /* OUT */)
1028{
1029 shape_plan->ot.collect_lookups (table_tag, lookup_indexes);
1030}
1031
1032
1033/* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
1034static void
1035add_char (hb_font_t *font,
1036 hb_unicode_funcs_t *unicode,
1037 hb_bool_t mirror,
1038 hb_codepoint_t u,
1039 hb_set_t *glyphs)
1040{
1041 hb_codepoint_t glyph;
1042 if (font->get_nominal_glyph (u, &glyph))
1043 glyphs->add (glyph);
1044 if (mirror)
1045 {
1046 hb_codepoint_t m = unicode->mirroring (u);
1047 if (m != u && font->get_nominal_glyph (m, &glyph))
1048 glyphs->add (glyph);
1049 }
1050}
1051
1052
1053/**
1054 * hb_ot_shape_glyphs_closure:
1055 *
1056 * Since: 0.9.2
1057 **/
1058void
1059hb_ot_shape_glyphs_closure (hb_font_t *font,
1060 hb_buffer_t *buffer,
1061 const hb_feature_t *features,
1062 unsigned int num_features,
1063 hb_set_t *glyphs)
1064{
1065 const char *shapers[] = {"ot", nullptr};
1066 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
1067 features, num_features, shapers);
1068
1069 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
1070
1071 unsigned int count = buffer->len;
1072 hb_glyph_info_t *info = buffer->info;
1073 for (unsigned int i = 0; i < count; i++)
1074 add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
1075
1076 hb_set_t *lookups = hb_set_create ();
1077 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, lookups);
1078 hb_ot_layout_lookups_substitute_closure (font->face, lookups, glyphs);
1079
1080 hb_set_destroy (lookups);
1081
1082 hb_shape_plan_destroy (shape_plan);
1083}
1084