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.hh"
30
31 #ifndef HB_NO_OT_SHAPE
32
33 #ifdef HB_NO_OT_LAYOUT
34 #error "Cannot compile 'ot' shaper with HB_NO_OT_LAYOUT."
35 #endif
36
37 #include "hb-shaper-impl.hh"
38
39 #include "hb-ot-shape.hh"
40 #include "hb-ot-shaper.hh"
41 #include "hb-ot-shape-fallback.hh"
42 #include "hb-ot-shape-normalize.hh"
43
44 #include "hb-ot-face.hh"
45
46 #include "hb-set.hh"
47
48 #include "hb-aat-layout.hh"
49
50 static inline bool
_hb_codepoint_is_regional_indicator(hb_codepoint_t u)51 _hb_codepoint_is_regional_indicator (hb_codepoint_t u)
52 { return hb_in_range<hb_codepoint_t> (u, 0x1F1E6u, 0x1F1FFu); }
53
54 #ifndef HB_NO_AAT_SHAPE
55 static inline bool
_hb_apply_morx(hb_face_t * face,const hb_segment_properties_t & props)56 _hb_apply_morx (hb_face_t *face, const hb_segment_properties_t &props)
57 {
58 /* https://github.com/harfbuzz/harfbuzz/issues/2124 */
59 return hb_aat_layout_has_substitution (face) &&
60 (HB_DIRECTION_IS_HORIZONTAL (props.direction) || !hb_ot_layout_has_substitution (face));
61 }
62 #endif
63
64 /**
65 * SECTION:hb-ot-shape
66 * @title: hb-ot-shape
67 * @short_description: OpenType shaping support
68 * @include: hb-ot.h
69 *
70 * Support functions for OpenType shaping related queries.
71 **/
72
73
74 static void
75 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
76 const hb_feature_t *user_features,
77 unsigned int num_user_features);
78
hb_ot_shape_planner_t(hb_face_t * face,const hb_segment_properties_t & props)79 hb_ot_shape_planner_t::hb_ot_shape_planner_t (hb_face_t *face,
80 const hb_segment_properties_t &props) :
81 face (face),
82 props (props),
83 map (face, props)
84 #ifndef HB_NO_AAT_SHAPE
85 , apply_morx (_hb_apply_morx (face, props))
86 #endif
87 {
88 shaper = hb_ot_shaper_categorize (this);
89
90 script_zero_marks = shaper->zero_width_marks != HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE;
91 script_fallback_mark_positioning = shaper->fallback_position;
92
93 #ifndef HB_NO_AAT_SHAPE
94 /* https://github.com/harfbuzz/harfbuzz/issues/1528 */
95 if (apply_morx && shaper != &_hb_ot_shaper_default)
96 shaper = &_hb_ot_shaper_dumber;
97 #endif
98 }
99
100 void
compile(hb_ot_shape_plan_t & plan,const hb_ot_shape_plan_key_t & key)101 hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t &plan,
102 const hb_ot_shape_plan_key_t &key)
103 {
104 plan.props = props;
105 plan.shaper = shaper;
106 map.compile (plan.map, key);
107
108 #ifndef HB_NO_OT_SHAPE_FRACTIONS
109 plan.frac_mask = plan.map.get_1_mask (HB_TAG ('f','r','a','c'));
110 plan.numr_mask = plan.map.get_1_mask (HB_TAG ('n','u','m','r'));
111 plan.dnom_mask = plan.map.get_1_mask (HB_TAG ('d','n','o','m'));
112 plan.has_frac = plan.frac_mask || (plan.numr_mask && plan.dnom_mask);
113 #endif
114
115 plan.rtlm_mask = plan.map.get_1_mask (HB_TAG ('r','t','l','m'));
116 plan.has_vert = !!plan.map.get_1_mask (HB_TAG ('v','e','r','t'));
117
118 hb_tag_t kern_tag = HB_DIRECTION_IS_HORIZONTAL (props.direction) ?
119 HB_TAG ('k','e','r','n') : HB_TAG ('v','k','r','n');
120 #ifndef HB_NO_OT_KERN
121 plan.kern_mask = plan.map.get_mask (kern_tag);
122 plan.requested_kerning = !!plan.kern_mask;
123 #endif
124 #ifndef HB_NO_AAT_SHAPE
125 plan.trak_mask = plan.map.get_mask (HB_TAG ('t','r','a','k'));
126 plan.requested_tracking = !!plan.trak_mask;
127 #endif
128
129 bool has_gpos_kern = plan.map.get_feature_index (1, kern_tag) != HB_OT_LAYOUT_NO_FEATURE_INDEX;
130 bool disable_gpos = plan.shaper->gpos_tag &&
131 plan.shaper->gpos_tag != plan.map.chosen_script[1];
132
133 /*
134 * Decide who provides glyph classes. GDEF or Unicode.
135 */
136
137 if (!hb_ot_layout_has_glyph_classes (face))
138 plan.fallback_glyph_classes = true;
139
140 /*
141 * Decide who does substitutions. GSUB, morx, or fallback.
142 */
143
144 #ifndef HB_NO_AAT_SHAPE
145 plan.apply_morx = apply_morx;
146 #endif
147
148 /*
149 * Decide who does positioning. GPOS, kerx, kern, or fallback.
150 */
151
152 #ifndef HB_NO_AAT_SHAPE
153 bool has_kerx = hb_aat_layout_has_positioning (face);
154 bool has_gsub = !apply_morx && hb_ot_layout_has_substitution (face);
155 #endif
156 bool has_gpos = !disable_gpos && hb_ot_layout_has_positioning (face);
157 if (false)
158 ;
159 #ifndef HB_NO_AAT_SHAPE
160 /* Prefer GPOS over kerx if GSUB is present;
161 * https://github.com/harfbuzz/harfbuzz/issues/3008 */
162 else if (has_kerx && !(has_gsub && has_gpos))
163 plan.apply_kerx = true;
164 #endif
165 else if (has_gpos)
166 plan.apply_gpos = true;
167
168 if (!plan.apply_kerx && (!has_gpos_kern || !plan.apply_gpos))
169 {
170 #ifndef HB_NO_AAT_SHAPE
171 if (has_kerx)
172 plan.apply_kerx = true;
173 else
174 #endif
175 #ifndef HB_NO_OT_KERN
176 if (hb_ot_layout_has_kerning (face))
177 plan.apply_kern = true;
178 #endif
179 }
180
181 plan.apply_fallback_kern = !(plan.apply_gpos || plan.apply_kerx || plan.apply_kern);
182
183 plan.zero_marks = script_zero_marks &&
184 !plan.apply_kerx &&
185 (!plan.apply_kern
186 #ifndef HB_NO_OT_KERN
187 || !hb_ot_layout_has_machine_kerning (face)
188 #endif
189 );
190 plan.has_gpos_mark = !!plan.map.get_1_mask (HB_TAG ('m','a','r','k'));
191
192 plan.adjust_mark_positioning_when_zeroing = !plan.apply_gpos &&
193 !plan.apply_kerx &&
194 (!plan.apply_kern
195 #ifndef HB_NO_OT_KERN
196 || !hb_ot_layout_has_cross_kerning (face)
197 #endif
198 );
199
200 plan.fallback_mark_positioning = plan.adjust_mark_positioning_when_zeroing &&
201 script_fallback_mark_positioning;
202
203 #ifndef HB_NO_AAT_SHAPE
204 /* If we're using morx shaping, we cancel mark position adjustment because
205 Apple Color Emoji assumes this will NOT be done when forming emoji sequences;
206 https://github.com/harfbuzz/harfbuzz/issues/2967. */
207 if (plan.apply_morx)
208 plan.adjust_mark_positioning_when_zeroing = false;
209
210 /* Currently we always apply trak. */
211 plan.apply_trak = plan.requested_tracking && hb_aat_layout_has_tracking (face);
212 #endif
213 }
214
215 bool
init0(hb_face_t * face,const hb_shape_plan_key_t * key)216 hb_ot_shape_plan_t::init0 (hb_face_t *face,
217 const hb_shape_plan_key_t *key)
218 {
219 map.init ();
220
221 hb_ot_shape_planner_t planner (face,
222 key->props);
223
224 hb_ot_shape_collect_features (&planner,
225 key->user_features,
226 key->num_user_features);
227
228 planner.compile (*this, key->ot);
229
230 if (shaper->data_create)
231 {
232 data = shaper->data_create (this);
233 if (unlikely (!data))
234 {
235 map.fini ();
236 return false;
237 }
238 }
239
240 return true;
241 }
242
243 void
fini()244 hb_ot_shape_plan_t::fini ()
245 {
246 if (shaper->data_destroy)
247 shaper->data_destroy (const_cast<void *> (data));
248
249 map.fini ();
250 }
251
252 void
substitute(hb_font_t * font,hb_buffer_t * buffer) const253 hb_ot_shape_plan_t::substitute (hb_font_t *font,
254 hb_buffer_t *buffer) const
255 {
256 map.substitute (this, font, buffer);
257 }
258
259 void
position(hb_font_t * font,hb_buffer_t * buffer) const260 hb_ot_shape_plan_t::position (hb_font_t *font,
261 hb_buffer_t *buffer) const
262 {
263 if (this->apply_gpos)
264 map.position (this, font, buffer);
265 #ifndef HB_NO_AAT_SHAPE
266 else if (this->apply_kerx)
267 hb_aat_layout_position (this, font, buffer);
268 #endif
269
270 #ifndef HB_NO_OT_KERN
271 if (this->apply_kern)
272 hb_ot_layout_kern (this, font, buffer);
273 #endif
274 else if (this->apply_fallback_kern)
275 _hb_ot_shape_fallback_kern (this, font, buffer);
276
277 #ifndef HB_NO_AAT_SHAPE
278 if (this->apply_trak)
279 hb_aat_layout_track (this, font, buffer);
280 #endif
281 }
282
283
284 static const hb_ot_map_feature_t
285 common_features[] =
286 {
287 {HB_TAG('a','b','v','m'), F_GLOBAL},
288 {HB_TAG('b','l','w','m'), F_GLOBAL},
289 {HB_TAG('c','c','m','p'), F_GLOBAL},
290 {HB_TAG('l','o','c','l'), F_GLOBAL},
291 {HB_TAG('m','a','r','k'), F_GLOBAL_MANUAL_JOINERS},
292 {HB_TAG('m','k','m','k'), F_GLOBAL_MANUAL_JOINERS},
293 {HB_TAG('r','l','i','g'), F_GLOBAL},
294 };
295
296
297 static const hb_ot_map_feature_t
298 horizontal_features[] =
299 {
300 {HB_TAG('c','a','l','t'), F_GLOBAL},
301 {HB_TAG('c','l','i','g'), F_GLOBAL},
302 {HB_TAG('c','u','r','s'), F_GLOBAL},
303 {HB_TAG('d','i','s','t'), F_GLOBAL},
304 {HB_TAG('k','e','r','n'), F_GLOBAL_HAS_FALLBACK},
305 {HB_TAG('l','i','g','a'), F_GLOBAL},
306 {HB_TAG('r','c','l','t'), F_GLOBAL},
307 };
308
309 static void
hb_ot_shape_collect_features(hb_ot_shape_planner_t * planner,const hb_feature_t * user_features,unsigned int num_user_features)310 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
311 const hb_feature_t *user_features,
312 unsigned int num_user_features)
313 {
314 hb_ot_map_builder_t *map = &planner->map;
315
316 map->is_simple = true;
317
318 map->enable_feature (HB_TAG('r','v','r','n'));
319 map->add_gsub_pause (nullptr);
320
321 switch (planner->props.direction)
322 {
323 case HB_DIRECTION_LTR:
324 map->enable_feature (HB_TAG ('l','t','r','a'));
325 map->enable_feature (HB_TAG ('l','t','r','m'));
326 break;
327 case HB_DIRECTION_RTL:
328 map->enable_feature (HB_TAG ('r','t','l','a'));
329 map->add_feature (HB_TAG ('r','t','l','m'));
330 break;
331 case HB_DIRECTION_TTB:
332 case HB_DIRECTION_BTT:
333 case HB_DIRECTION_INVALID:
334 default:
335 break;
336 }
337
338 #ifndef HB_NO_OT_SHAPE_FRACTIONS
339 /* Automatic fractions. */
340 map->add_feature (HB_TAG ('f','r','a','c'));
341 map->add_feature (HB_TAG ('n','u','m','r'));
342 map->add_feature (HB_TAG ('d','n','o','m'));
343 #endif
344
345 /* Random! */
346 map->enable_feature (HB_TAG ('r','a','n','d'), F_RANDOM, HB_OT_MAP_MAX_VALUE);
347
348 #ifndef HB_NO_AAT_SHAPE
349 /* Tracking. We enable dummy feature here just to allow disabling
350 * AAT 'trak' table using features.
351 * https://github.com/harfbuzz/harfbuzz/issues/1303 */
352 map->enable_feature (HB_TAG ('t','r','a','k'), F_HAS_FALLBACK);
353 #endif
354
355 map->enable_feature (HB_TAG ('H','a','r','f')); /* Considered required. */
356 map->enable_feature (HB_TAG ('H','A','R','F')); /* Considered discretionary. */
357
358 if (planner->shaper->collect_features)
359 {
360 map->is_simple = false;
361 planner->shaper->collect_features (planner);
362 }
363
364 map->enable_feature (HB_TAG ('B','u','z','z')); /* Considered required. */
365 map->enable_feature (HB_TAG ('B','U','Z','Z')); /* Considered discretionary. */
366
367 for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
368 map->add_feature (common_features[i]);
369
370 if (HB_DIRECTION_IS_HORIZONTAL (planner->props.direction))
371 for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
372 map->add_feature (horizontal_features[i]);
373 else
374 {
375 /* We only apply `vert` feature. See:
376 * https://github.com/harfbuzz/harfbuzz/commit/d71c0df2d17f4590d5611239577a6cb532c26528
377 * https://lists.freedesktop.org/archives/harfbuzz/2013-August/003490.html */
378
379 /* We really want to find a 'vert' feature if there's any in the font, no
380 * matter which script/langsys it is listed (or not) under.
381 * See various bugs referenced from:
382 * https://github.com/harfbuzz/harfbuzz/issues/63 */
383 map->enable_feature (HB_TAG ('v','e','r','t'), F_GLOBAL_SEARCH);
384 }
385
386 if (num_user_features)
387 map->is_simple = false;
388 for (unsigned int i = 0; i < num_user_features; i++)
389 {
390 const hb_feature_t *feature = &user_features[i];
391 map->add_feature (feature->tag,
392 (feature->start == HB_FEATURE_GLOBAL_START &&
393 feature->end == HB_FEATURE_GLOBAL_END) ? F_GLOBAL : F_NONE,
394 feature->value);
395 }
396
397 if (planner->shaper->override_features)
398 planner->shaper->override_features (planner);
399 }
400
401
402 /*
403 * shaper face data
404 */
405
406 struct hb_ot_face_data_t {};
407
408 hb_ot_face_data_t *
_hb_ot_shaper_face_data_create(hb_face_t * face)409 _hb_ot_shaper_face_data_create (hb_face_t *face)
410 {
411 return (hb_ot_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
412 }
413
414 void
_hb_ot_shaper_face_data_destroy(hb_ot_face_data_t * data)415 _hb_ot_shaper_face_data_destroy (hb_ot_face_data_t *data)
416 {
417 }
418
419
420 /*
421 * shaper font data
422 */
423
424 struct hb_ot_font_data_t {};
425
426 hb_ot_font_data_t *
_hb_ot_shaper_font_data_create(hb_font_t * font HB_UNUSED)427 _hb_ot_shaper_font_data_create (hb_font_t *font HB_UNUSED)
428 {
429 return (hb_ot_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
430 }
431
432 void
_hb_ot_shaper_font_data_destroy(hb_ot_font_data_t * data HB_UNUSED)433 _hb_ot_shaper_font_data_destroy (hb_ot_font_data_t *data HB_UNUSED)
434 {
435 }
436
437
438 /*
439 * shaper
440 */
441
442 struct hb_ot_shape_context_t
443 {
444 hb_ot_shape_plan_t *plan;
445 hb_font_t *font;
446 hb_face_t *face;
447 hb_buffer_t *buffer;
448 const hb_feature_t *user_features;
449 unsigned int num_user_features;
450
451 /* Transient stuff */
452 hb_direction_t target_direction;
453 };
454
455
456
457 /* Main shaper */
458
459
460 /* Prepare */
461
462 static void
hb_set_unicode_props(hb_buffer_t * buffer)463 hb_set_unicode_props (hb_buffer_t *buffer)
464 {
465 /* Implement enough of Unicode Graphemes here that shaping
466 * in reverse-direction wouldn't break graphemes. Namely,
467 * we mark all marks and ZWJ and ZWJ,Extended_Pictographic
468 * sequences as continuations. The foreach_grapheme()
469 * macro uses this bit.
470 *
471 * https://www.unicode.org/reports/tr29/#Regex_Definitions
472 */
473 unsigned int count = buffer->len;
474 hb_glyph_info_t *info = buffer->info;
475 for (unsigned int i = 0; i < count; i++)
476 {
477 _hb_glyph_info_set_unicode_props (&info[i], buffer);
478
479 unsigned gen_cat = _hb_glyph_info_get_general_category (&info[i]);
480 if (FLAG_UNSAFE (gen_cat) &
481 (FLAG (HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER) |
482 FLAG (HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER) |
483 FLAG (HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER) |
484 FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) |
485 FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR)))
486 continue;
487
488 /* Marks are already set as continuation by the above line.
489 * Handle Emoji_Modifier and ZWJ-continuation. */
490 if (unlikely (gen_cat == HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL &&
491 hb_in_range<hb_codepoint_t> (info[i].codepoint, 0x1F3FBu, 0x1F3FFu)))
492 {
493 _hb_glyph_info_set_continuation (&info[i]);
494 }
495 /* Regional_Indicators are hairy as hell...
496 * https://github.com/harfbuzz/harfbuzz/issues/2265 */
497 else if (unlikely (i && _hb_codepoint_is_regional_indicator (info[i].codepoint)))
498 {
499 if (_hb_codepoint_is_regional_indicator (info[i - 1].codepoint) &&
500 !_hb_glyph_info_is_continuation (&info[i - 1]))
501 _hb_glyph_info_set_continuation (&info[i]);
502 }
503 #ifndef HB_NO_EMOJI_SEQUENCES
504 else if (unlikely (_hb_glyph_info_is_zwj (&info[i])))
505 {
506 _hb_glyph_info_set_continuation (&info[i]);
507 if (i + 1 < count &&
508 _hb_unicode_is_emoji_Extended_Pictographic (info[i + 1].codepoint))
509 {
510 i++;
511 _hb_glyph_info_set_unicode_props (&info[i], buffer);
512 _hb_glyph_info_set_continuation (&info[i]);
513 }
514 }
515 #endif
516 /* Or part of the Other_Grapheme_Extend that is not marks.
517 * As of Unicode 15 that is just:
518 *
519 * 200C ; Other_Grapheme_Extend # Cf ZERO WIDTH NON-JOINER
520 * FF9E..FF9F ; Other_Grapheme_Extend # Lm [2] HALFWIDTH KATAKANA VOICED SOUND MARK..HALFWIDTH KATAKANA SEMI-VOICED SOUND MARK
521 * E0020..E007F ; Other_Grapheme_Extend # Cf [96] TAG SPACE..CANCEL TAG
522 *
523 * ZWNJ is special, we don't want to merge it as there's no need, and keeping
524 * it separate results in more granular clusters.
525 * Tags are used for Emoji sub-region flag sequences:
526 * https://github.com/harfbuzz/harfbuzz/issues/1556
527 * Katakana ones were requested:
528 * https://github.com/harfbuzz/harfbuzz/issues/3844
529 */
530 else if (unlikely (hb_in_ranges<hb_codepoint_t> (info[i].codepoint, 0xFF9Eu, 0xFF9Fu, 0xE0020u, 0xE007Fu)))
531 _hb_glyph_info_set_continuation (&info[i]);
532 }
533 }
534
535 static void
hb_insert_dotted_circle(hb_buffer_t * buffer,hb_font_t * font)536 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
537 {
538 if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
539 return;
540
541 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
542 buffer->context_len[0] ||
543 !_hb_glyph_info_is_unicode_mark (&buffer->info[0]))
544 return;
545
546 if (!font->has_glyph (0x25CCu))
547 return;
548
549 hb_glyph_info_t dottedcircle = {0};
550 dottedcircle.codepoint = 0x25CCu;
551 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer);
552
553 buffer->clear_output ();
554
555 buffer->idx = 0;
556 hb_glyph_info_t info = dottedcircle;
557 info.cluster = buffer->cur().cluster;
558 info.mask = buffer->cur().mask;
559 (void) buffer->output_info (info);
560
561 buffer->sync ();
562 }
563
564 static void
hb_form_clusters(hb_buffer_t * buffer)565 hb_form_clusters (hb_buffer_t *buffer)
566 {
567 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII))
568 return;
569
570 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
571 foreach_grapheme (buffer, start, end)
572 buffer->merge_clusters (start, end);
573 else
574 foreach_grapheme (buffer, start, end)
575 buffer->unsafe_to_break (start, end);
576 }
577
578 static void
hb_ensure_native_direction(hb_buffer_t * buffer)579 hb_ensure_native_direction (hb_buffer_t *buffer)
580 {
581 hb_direction_t direction = buffer->props.direction;
582 hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
583
584 /* Numeric runs in natively-RTL scripts are actually native-LTR, so we reset
585 * the horiz_dir if the run contains at least one decimal-number char, and no
586 * letter chars (ideally we should be checking for chars with strong
587 * directionality but hb-unicode currently lacks bidi categories).
588 *
589 * This allows digit sequences in Arabic etc to be shaped in "native"
590 * direction, so that features like ligatures will work as intended.
591 *
592 * https://github.com/harfbuzz/harfbuzz/issues/501
593 *
594 * Similar thing about Regional_Indicators; They are bidi=L, but Script=Common.
595 * If they are present in a run of natively-RTL text, they get assigned a script
596 * with natively RTL direction, which would result in wrong shaping if we
597 * assign such native RTL direction to them then. Detect that as well.
598 *
599 * https://github.com/harfbuzz/harfbuzz/issues/3314
600 */
601 if (unlikely (horiz_dir == HB_DIRECTION_RTL && direction == HB_DIRECTION_LTR))
602 {
603 bool found_number = false, found_letter = false, found_ri = false;
604 const auto* info = buffer->info;
605 const auto count = buffer->len;
606 for (unsigned i = 0; i < count; i++)
607 {
608 auto gc = _hb_glyph_info_get_general_category (&info[i]);
609 if (gc == HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
610 found_number = true;
611 else if (HB_UNICODE_GENERAL_CATEGORY_IS_LETTER (gc))
612 {
613 found_letter = true;
614 break;
615 }
616 else if (_hb_codepoint_is_regional_indicator (info[i].codepoint))
617 found_ri = true;
618 }
619 if ((found_number || found_ri) && !found_letter)
620 horiz_dir = HB_DIRECTION_LTR;
621 }
622
623 /* TODO vertical:
624 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
625 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
626 * first. */
627 if ((HB_DIRECTION_IS_HORIZONTAL (direction) &&
628 direction != horiz_dir && horiz_dir != HB_DIRECTION_INVALID) ||
629 (HB_DIRECTION_IS_VERTICAL (direction) &&
630 direction != HB_DIRECTION_TTB))
631 {
632 _hb_ot_layout_reverse_graphemes (buffer);
633 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
634 }
635 }
636
637
638 /*
639 * Substitute
640 */
641
642 #ifndef HB_NO_VERTICAL
643 static hb_codepoint_t
hb_vert_char_for(hb_codepoint_t u)644 hb_vert_char_for (hb_codepoint_t u)
645 {
646 switch (u >> 8)
647 {
648 case 0x20: switch (u) {
649 case 0x2013u: return 0xfe32u; // EN DASH
650 case 0x2014u: return 0xfe31u; // EM DASH
651 case 0x2025u: return 0xfe30u; // TWO DOT LEADER
652 case 0x2026u: return 0xfe19u; // HORIZONTAL ELLIPSIS
653 } break;
654 case 0x30: switch (u) {
655 case 0x3001u: return 0xfe11u; // IDEOGRAPHIC COMMA
656 case 0x3002u: return 0xfe12u; // IDEOGRAPHIC FULL STOP
657 case 0x3008u: return 0xfe3fu; // LEFT ANGLE BRACKET
658 case 0x3009u: return 0xfe40u; // RIGHT ANGLE BRACKET
659 case 0x300au: return 0xfe3du; // LEFT DOUBLE ANGLE BRACKET
660 case 0x300bu: return 0xfe3eu; // RIGHT DOUBLE ANGLE BRACKET
661 case 0x300cu: return 0xfe41u; // LEFT CORNER BRACKET
662 case 0x300du: return 0xfe42u; // RIGHT CORNER BRACKET
663 case 0x300eu: return 0xfe43u; // LEFT WHITE CORNER BRACKET
664 case 0x300fu: return 0xfe44u; // RIGHT WHITE CORNER BRACKET
665 case 0x3010u: return 0xfe3bu; // LEFT BLACK LENTICULAR BRACKET
666 case 0x3011u: return 0xfe3cu; // RIGHT BLACK LENTICULAR BRACKET
667 case 0x3014u: return 0xfe39u; // LEFT TORTOISE SHELL BRACKET
668 case 0x3015u: return 0xfe3au; // RIGHT TORTOISE SHELL BRACKET
669 case 0x3016u: return 0xfe17u; // LEFT WHITE LENTICULAR BRACKET
670 case 0x3017u: return 0xfe18u; // RIGHT WHITE LENTICULAR BRACKET
671 } break;
672 case 0xfe: switch (u) {
673 case 0xfe4fu: return 0xfe34u; // WAVY LOW LINE
674 } break;
675 case 0xff: switch (u) {
676 case 0xff01u: return 0xfe15u; // FULLWIDTH EXCLAMATION MARK
677 case 0xff08u: return 0xfe35u; // FULLWIDTH LEFT PARENTHESIS
678 case 0xff09u: return 0xfe36u; // FULLWIDTH RIGHT PARENTHESIS
679 case 0xff0cu: return 0xfe10u; // FULLWIDTH COMMA
680 case 0xff1au: return 0xfe13u; // FULLWIDTH COLON
681 case 0xff1bu: return 0xfe14u; // FULLWIDTH SEMICOLON
682 case 0xff1fu: return 0xfe16u; // FULLWIDTH QUESTION MARK
683 case 0xff3bu: return 0xfe47u; // FULLWIDTH LEFT SQUARE BRACKET
684 case 0xff3du: return 0xfe48u; // FULLWIDTH RIGHT SQUARE BRACKET
685 case 0xff3fu: return 0xfe33u; // FULLWIDTH LOW LINE
686 case 0xff5bu: return 0xfe37u; // FULLWIDTH LEFT CURLY BRACKET
687 case 0xff5du: return 0xfe38u; // FULLWIDTH RIGHT CURLY BRACKET
688 } break;
689 }
690
691 return u;
692 }
693 #endif
694
695 static inline void
hb_ot_rotate_chars(const hb_ot_shape_context_t * c)696 hb_ot_rotate_chars (const hb_ot_shape_context_t *c)
697 {
698 hb_buffer_t *buffer = c->buffer;
699 unsigned int count = buffer->len;
700 hb_glyph_info_t *info = buffer->info;
701
702 if (HB_DIRECTION_IS_BACKWARD (c->target_direction))
703 {
704 hb_unicode_funcs_t *unicode = buffer->unicode;
705 hb_mask_t rtlm_mask = c->plan->rtlm_mask;
706
707 for (unsigned int i = 0; i < count; i++) {
708 hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
709 if (unlikely (codepoint != info[i].codepoint && c->font->has_glyph (codepoint)))
710 info[i].codepoint = codepoint;
711 else
712 info[i].mask |= rtlm_mask;
713 }
714 }
715
716 #ifndef HB_NO_VERTICAL
717 if (HB_DIRECTION_IS_VERTICAL (c->target_direction) && !c->plan->has_vert)
718 {
719 for (unsigned int i = 0; i < count; i++) {
720 hb_codepoint_t codepoint = hb_vert_char_for (info[i].codepoint);
721 if (unlikely (codepoint != info[i].codepoint && c->font->has_glyph (codepoint)))
722 info[i].codepoint = codepoint;
723 }
724 }
725 #endif
726 }
727
728 static inline void
hb_ot_shape_setup_masks_fraction(const hb_ot_shape_context_t * c)729 hb_ot_shape_setup_masks_fraction (const hb_ot_shape_context_t *c)
730 {
731 #ifdef HB_NO_OT_SHAPE_FRACTIONS
732 return;
733 #endif
734
735 if (!(c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII) ||
736 !c->plan->has_frac)
737 return;
738
739 hb_buffer_t *buffer = c->buffer;
740
741 hb_mask_t pre_mask, post_mask;
742 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
743 {
744 pre_mask = c->plan->numr_mask | c->plan->frac_mask;
745 post_mask = c->plan->frac_mask | c->plan->dnom_mask;
746 }
747 else
748 {
749 pre_mask = c->plan->frac_mask | c->plan->dnom_mask;
750 post_mask = c->plan->numr_mask | c->plan->frac_mask;
751 }
752
753 unsigned int count = buffer->len;
754 hb_glyph_info_t *info = buffer->info;
755 for (unsigned int i = 0; i < count; i++)
756 {
757 if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
758 {
759 unsigned int start = i, end = i + 1;
760 while (start &&
761 _hb_glyph_info_get_general_category (&info[start - 1]) ==
762 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
763 start--;
764 while (end < count &&
765 _hb_glyph_info_get_general_category (&info[end]) ==
766 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
767 end++;
768 if (start == i || end == i + 1)
769 {
770 if (start == i)
771 buffer->unsafe_to_concat (start, start + 1);
772 if (end == i + 1)
773 buffer->unsafe_to_concat (end - 1, end);
774 continue;
775 }
776
777 buffer->unsafe_to_break (start, end);
778
779 for (unsigned int j = start; j < i; j++)
780 info[j].mask |= pre_mask;
781 info[i].mask |= c->plan->frac_mask;
782 for (unsigned int j = i + 1; j < end; j++)
783 info[j].mask |= post_mask;
784
785 i = end - 1;
786 }
787 }
788 }
789
790 static inline void
hb_ot_shape_initialize_masks(const hb_ot_shape_context_t * c)791 hb_ot_shape_initialize_masks (const hb_ot_shape_context_t *c)
792 {
793 hb_ot_map_t *map = &c->plan->map;
794 hb_buffer_t *buffer = c->buffer;
795
796 hb_mask_t global_mask = map->get_global_mask ();
797 buffer->reset_masks (global_mask);
798 }
799
800 static inline void
hb_ot_shape_setup_masks(const hb_ot_shape_context_t * c)801 hb_ot_shape_setup_masks (const hb_ot_shape_context_t *c)
802 {
803 hb_ot_map_t *map = &c->plan->map;
804 hb_buffer_t *buffer = c->buffer;
805
806 hb_ot_shape_setup_masks_fraction (c);
807
808 if (c->plan->shaper->setup_masks)
809 c->plan->shaper->setup_masks (c->plan, buffer, c->font);
810
811 for (unsigned int i = 0; i < c->num_user_features; i++)
812 {
813 const hb_feature_t *feature = &c->user_features[i];
814 if (!(feature->start == HB_FEATURE_GLOBAL_START && feature->end == HB_FEATURE_GLOBAL_END)) {
815 unsigned int shift;
816 hb_mask_t mask = map->get_mask (feature->tag, &shift);
817 buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
818 }
819 }
820 }
821
822 static void
hb_ot_zero_width_default_ignorables(const hb_buffer_t * buffer)823 hb_ot_zero_width_default_ignorables (const hb_buffer_t *buffer)
824 {
825 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
826 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) ||
827 (buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES))
828 return;
829
830 unsigned int count = buffer->len;
831 hb_glyph_info_t *info = buffer->info;
832 hb_glyph_position_t *pos = buffer->pos;
833 unsigned int i = 0;
834 for (i = 0; i < count; i++)
835 if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
836 pos[i].x_advance = pos[i].y_advance = pos[i].x_offset = pos[i].y_offset = 0;
837 }
838
839 static void
hb_ot_hide_default_ignorables(hb_buffer_t * buffer,hb_font_t * font)840 hb_ot_hide_default_ignorables (hb_buffer_t *buffer,
841 hb_font_t *font)
842 {
843 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
844 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES))
845 return;
846
847 unsigned int count = buffer->len;
848 hb_glyph_info_t *info = buffer->info;
849
850 hb_codepoint_t invisible = buffer->invisible;
851 if (!(buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES) &&
852 (invisible || font->get_nominal_glyph (' ', &invisible)))
853 {
854 /* Replace default-ignorables with a zero-advance invisible glyph. */
855 for (unsigned int i = 0; i < count; i++)
856 {
857 if (_hb_glyph_info_is_default_ignorable (&info[i]))
858 info[i].codepoint = invisible;
859 }
860 }
861 else
862 buffer->delete_glyphs_inplace (_hb_glyph_info_is_default_ignorable);
863 }
864
865
866 static inline void
hb_ot_map_glyphs_fast(hb_buffer_t * buffer)867 hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
868 {
869 /* Normalization process sets up glyph_index(), we just copy it. */
870 unsigned int count = buffer->len;
871 hb_glyph_info_t *info = buffer->info;
872 for (unsigned int i = 0; i < count; i++)
873 info[i].codepoint = info[i].glyph_index();
874
875 buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
876 }
877
878 static inline void
hb_synthesize_glyph_classes(hb_buffer_t * buffer)879 hb_synthesize_glyph_classes (hb_buffer_t *buffer)
880 {
881 unsigned int count = buffer->len;
882 hb_glyph_info_t *info = buffer->info;
883 for (unsigned int i = 0; i < count; i++)
884 {
885 hb_ot_layout_glyph_props_flags_t klass;
886
887 /* Never mark default-ignorables as marks.
888 * They won't get in the way of lookups anyway,
889 * but having them as mark will cause them to be skipped
890 * over if the lookup-flag says so, but at least for the
891 * Mongolian variation selectors, looks like Uniscribe
892 * marks them as non-mark. Some Mongolian fonts without
893 * GDEF rely on this. Another notable character that
894 * this applies to is COMBINING GRAPHEME JOINER. */
895 klass = (_hb_glyph_info_get_general_category (&info[i]) !=
896 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
897 _hb_glyph_info_is_default_ignorable (&info[i])) ?
898 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
899 HB_OT_LAYOUT_GLYPH_PROPS_MARK;
900 _hb_glyph_info_set_glyph_props (&info[i], klass);
901 }
902 }
903
904 static inline void
hb_ot_substitute_default(const hb_ot_shape_context_t * c)905 hb_ot_substitute_default (const hb_ot_shape_context_t *c)
906 {
907 hb_buffer_t *buffer = c->buffer;
908
909 hb_ot_rotate_chars (c);
910
911 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
912
913 _hb_ot_shape_normalize (c->plan, buffer, c->font);
914
915 hb_ot_shape_setup_masks (c);
916
917 /* This is unfortunate to go here, but necessary... */
918 if (c->plan->fallback_mark_positioning)
919 _hb_ot_shape_fallback_mark_position_recategorize_marks (c->plan, c->font, buffer);
920
921 hb_ot_map_glyphs_fast (buffer);
922
923 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
924 }
925
926 static inline void
hb_ot_substitute_plan(const hb_ot_shape_context_t * c)927 hb_ot_substitute_plan (const hb_ot_shape_context_t *c)
928 {
929 hb_buffer_t *buffer = c->buffer;
930
931 hb_ot_layout_substitute_start (c->font, buffer);
932
933 if (c->plan->fallback_glyph_classes)
934 hb_synthesize_glyph_classes (c->buffer);
935
936 #ifndef HB_NO_AAT_SHAPE
937 if (unlikely (c->plan->apply_morx))
938 hb_aat_layout_substitute (c->plan, c->font, c->buffer,
939 c->user_features, c->num_user_features);
940 else
941 #endif
942 c->plan->substitute (c->font, buffer);
943 }
944
945 static inline void
hb_ot_substitute_pre(const hb_ot_shape_context_t * c)946 hb_ot_substitute_pre (const hb_ot_shape_context_t *c)
947 {
948 hb_ot_substitute_default (c);
949
950 _hb_buffer_allocate_gsubgpos_vars (c->buffer);
951
952 hb_ot_substitute_plan (c);
953
954 #ifndef HB_NO_AAT_SHAPE
955 if (c->plan->apply_morx && c->plan->apply_gpos)
956 hb_aat_layout_remove_deleted_glyphs (c->buffer);
957 #endif
958 }
959
960 static inline void
hb_ot_substitute_post(const hb_ot_shape_context_t * c)961 hb_ot_substitute_post (const hb_ot_shape_context_t *c)
962 {
963 #ifndef HB_NO_AAT_SHAPE
964 if (c->plan->apply_morx && !c->plan->apply_gpos)
965 hb_aat_layout_remove_deleted_glyphs (c->buffer);
966 #endif
967
968 hb_ot_hide_default_ignorables (c->buffer, c->font);
969
970 if (c->plan->shaper->postprocess_glyphs &&
971 c->buffer->message(c->font, "start postprocess-glyphs")) {
972 c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
973 (void) c->buffer->message(c->font, "end postprocess-glyphs");
974 }
975 }
976
977
978 /*
979 * Position
980 */
981
982 static inline void
adjust_mark_offsets(hb_glyph_position_t * pos)983 adjust_mark_offsets (hb_glyph_position_t *pos)
984 {
985 pos->x_offset -= pos->x_advance;
986 pos->y_offset -= pos->y_advance;
987 }
988
989 static inline void
zero_mark_width(hb_glyph_position_t * pos)990 zero_mark_width (hb_glyph_position_t *pos)
991 {
992 pos->x_advance = 0;
993 pos->y_advance = 0;
994 }
995
996 static inline void
zero_mark_widths_by_gdef(hb_buffer_t * buffer,bool adjust_offsets)997 zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
998 {
999 unsigned int count = buffer->len;
1000 hb_glyph_info_t *info = buffer->info;
1001 for (unsigned int i = 0; i < count; i++)
1002 if (_hb_glyph_info_is_mark (&info[i]))
1003 {
1004 if (adjust_offsets)
1005 adjust_mark_offsets (&buffer->pos[i]);
1006 zero_mark_width (&buffer->pos[i]);
1007 }
1008 }
1009
1010 static inline void
hb_ot_position_default(const hb_ot_shape_context_t * c)1011 hb_ot_position_default (const hb_ot_shape_context_t *c)
1012 {
1013 hb_direction_t direction = c->buffer->props.direction;
1014 unsigned int count = c->buffer->len;
1015 hb_glyph_info_t *info = c->buffer->info;
1016 hb_glyph_position_t *pos = c->buffer->pos;
1017
1018 if (HB_DIRECTION_IS_HORIZONTAL (direction))
1019 {
1020 c->font->get_glyph_h_advances (count, &info[0].codepoint, sizeof(info[0]),
1021 &pos[0].x_advance, sizeof(pos[0]));
1022 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
1023 if (c->font->has_glyph_h_origin_func ())
1024 for (unsigned int i = 0; i < count; i++)
1025 c->font->subtract_glyph_h_origin (info[i].codepoint,
1026 &pos[i].x_offset,
1027 &pos[i].y_offset);
1028 }
1029 else
1030 {
1031 c->font->get_glyph_v_advances (count, &info[0].codepoint, sizeof(info[0]),
1032 &pos[0].y_advance, sizeof(pos[0]));
1033 for (unsigned int i = 0; i < count; i++)
1034 {
1035 c->font->subtract_glyph_v_origin (info[i].codepoint,
1036 &pos[i].x_offset,
1037 &pos[i].y_offset);
1038 }
1039 }
1040 if (c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK)
1041 _hb_ot_shape_fallback_spaces (c->plan, c->font, c->buffer);
1042 }
1043
1044 static inline void
hb_ot_position_plan(const hb_ot_shape_context_t * c)1045 hb_ot_position_plan (const hb_ot_shape_context_t *c)
1046 {
1047 unsigned int count = c->buffer->len;
1048 hb_glyph_info_t *info = c->buffer->info;
1049 hb_glyph_position_t *pos = c->buffer->pos;
1050
1051 /* If the font has no GPOS and direction is forward, then when
1052 * zeroing mark widths, we shift the mark with it, such that the
1053 * mark is positioned hanging over the previous glyph. When
1054 * direction is backward we don't shift and it will end up
1055 * hanging over the next glyph after the final reordering.
1056 *
1057 * Note: If fallback positioning happens, we don't care about
1058 * this as it will be overridden.
1059 */
1060 bool adjust_offsets_when_zeroing = c->plan->adjust_mark_positioning_when_zeroing &&
1061 HB_DIRECTION_IS_FORWARD (c->buffer->props.direction);
1062
1063 /* We change glyph origin to what GPOS expects (horizontal), apply GPOS, change it back. */
1064
1065 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
1066 if (c->font->has_glyph_h_origin_func ())
1067 for (unsigned int i = 0; i < count; i++)
1068 c->font->add_glyph_h_origin (info[i].codepoint,
1069 &pos[i].x_offset,
1070 &pos[i].y_offset);
1071
1072 hb_ot_layout_position_start (c->font, c->buffer);
1073
1074 if (c->plan->zero_marks)
1075 switch (c->plan->shaper->zero_width_marks)
1076 {
1077 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
1078 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
1079 break;
1080
1081 default:
1082 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
1083 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
1084 break;
1085 }
1086
1087 c->plan->position (c->font, c->buffer);
1088
1089 if (c->plan->zero_marks)
1090 switch (c->plan->shaper->zero_width_marks)
1091 {
1092 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
1093 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
1094 break;
1095
1096 default:
1097 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
1098 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
1099 break;
1100 }
1101
1102 /* Finish off. Has to follow a certain order. */
1103 hb_ot_layout_position_finish_advances (c->font, c->buffer);
1104 hb_ot_zero_width_default_ignorables (c->buffer);
1105 #ifndef HB_NO_AAT_SHAPE
1106 if (c->plan->apply_morx)
1107 hb_aat_layout_zero_width_deleted_glyphs (c->buffer);
1108 #endif
1109 hb_ot_layout_position_finish_offsets (c->font, c->buffer);
1110
1111 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
1112 if (c->font->has_glyph_h_origin_func ())
1113 for (unsigned int i = 0; i < count; i++)
1114 c->font->subtract_glyph_h_origin (info[i].codepoint,
1115 &pos[i].x_offset,
1116 &pos[i].y_offset);
1117
1118 if (c->plan->fallback_mark_positioning)
1119 _hb_ot_shape_fallback_mark_position (c->plan, c->font, c->buffer,
1120 adjust_offsets_when_zeroing);
1121 }
1122
1123 static inline void
hb_ot_position(const hb_ot_shape_context_t * c)1124 hb_ot_position (const hb_ot_shape_context_t *c)
1125 {
1126 c->buffer->clear_positions ();
1127
1128 hb_ot_position_default (c);
1129
1130 hb_ot_position_plan (c);
1131
1132 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
1133 hb_buffer_reverse (c->buffer);
1134
1135 _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
1136 }
1137
1138 static inline void
hb_propagate_flags(hb_buffer_t * buffer)1139 hb_propagate_flags (hb_buffer_t *buffer)
1140 {
1141 /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
1142 * Simplifies using them. */
1143
1144 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_GLYPH_FLAGS))
1145 return;
1146
1147 /* If we are producing SAFE_TO_INSERT_TATWEEL, then do two things:
1148 *
1149 * - If the places that the Arabic shaper marked as SAFE_TO_INSERT_TATWEEL,
1150 * are UNSAFE_TO_BREAK, then clear the SAFE_TO_INSERT_TATWEEL,
1151 * - Any place that is SAFE_TO_INSERT_TATWEEL, is also now UNSAFE_TO_BREAK.
1152 *
1153 * We couldn't make this interaction earlier. It has to be done here.
1154 */
1155 bool flip_tatweel = buffer->flags & HB_BUFFER_FLAG_PRODUCE_SAFE_TO_INSERT_TATWEEL;
1156
1157 bool clear_concat = (buffer->flags & HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT) == 0;
1158
1159 hb_glyph_info_t *info = buffer->info;
1160
1161 foreach_cluster (buffer, start, end)
1162 {
1163 unsigned int mask = 0;
1164 for (unsigned int i = start; i < end; i++)
1165 mask |= info[i].mask & HB_GLYPH_FLAG_DEFINED;
1166
1167 if (flip_tatweel)
1168 {
1169 if (mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
1170 mask &= ~HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL;
1171 if (mask & HB_GLYPH_FLAG_SAFE_TO_INSERT_TATWEEL)
1172 mask |= HB_GLYPH_FLAG_UNSAFE_TO_BREAK | HB_GLYPH_FLAG_UNSAFE_TO_CONCAT;
1173 }
1174
1175 if (clear_concat)
1176 mask &= ~HB_GLYPH_FLAG_UNSAFE_TO_CONCAT;
1177
1178 for (unsigned int i = start; i < end; i++)
1179 info[i].mask = mask;
1180 }
1181 }
1182
1183 /* Pull it all together! */
1184
1185 static void
hb_ot_shape_internal(hb_ot_shape_context_t * c)1186 hb_ot_shape_internal (hb_ot_shape_context_t *c)
1187 {
1188 /* Save the original direction, we use it later. */
1189 c->target_direction = c->buffer->props.direction;
1190
1191 _hb_buffer_allocate_unicode_vars (c->buffer);
1192
1193 hb_ot_shape_initialize_masks (c);
1194 hb_set_unicode_props (c->buffer);
1195 hb_insert_dotted_circle (c->buffer, c->font);
1196
1197 hb_form_clusters (c->buffer);
1198
1199 hb_ensure_native_direction (c->buffer);
1200
1201 if (c->plan->shaper->preprocess_text &&
1202 c->buffer->message(c->font, "start preprocess-text"))
1203 {
1204 c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
1205 (void) c->buffer->message(c->font, "end preprocess-text");
1206 }
1207
1208 hb_ot_substitute_pre (c);
1209 hb_ot_position (c);
1210 hb_ot_substitute_post (c);
1211
1212 hb_propagate_flags (c->buffer);
1213
1214 _hb_buffer_deallocate_unicode_vars (c->buffer);
1215
1216 c->buffer->props.direction = c->target_direction;
1217
1218 c->buffer->leave ();
1219 }
1220
1221
1222 hb_bool_t
_hb_ot_shape(hb_shape_plan_t * shape_plan,hb_font_t * font,hb_buffer_t * buffer,const hb_feature_t * features,unsigned int num_features)1223 _hb_ot_shape (hb_shape_plan_t *shape_plan,
1224 hb_font_t *font,
1225 hb_buffer_t *buffer,
1226 const hb_feature_t *features,
1227 unsigned int num_features)
1228 {
1229 hb_ot_shape_context_t c = {&shape_plan->ot, font, font->face, buffer, features, num_features};
1230 hb_ot_shape_internal (&c);
1231
1232 return true;
1233 }
1234
1235
1236 /**
1237 * hb_ot_shape_plan_collect_lookups:
1238 * @shape_plan: #hb_shape_plan_t to query
1239 * @table_tag: GSUB or GPOS
1240 * @lookup_indexes: (out): The #hb_set_t set of lookups returned
1241 *
1242 * Computes the complete set of GSUB or GPOS lookups that are applicable
1243 * under a given @shape_plan.
1244 *
1245 * Since: 0.9.7
1246 **/
1247 void
hb_ot_shape_plan_collect_lookups(hb_shape_plan_t * shape_plan,hb_tag_t table_tag,hb_set_t * lookup_indexes)1248 hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
1249 hb_tag_t table_tag,
1250 hb_set_t *lookup_indexes /* OUT */)
1251 {
1252 shape_plan->ot.collect_lookups (table_tag, lookup_indexes);
1253 }
1254
1255
1256 /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
1257 static void
add_char(hb_font_t * font,hb_unicode_funcs_t * unicode,hb_bool_t mirror,hb_codepoint_t u,hb_set_t * glyphs)1258 add_char (hb_font_t *font,
1259 hb_unicode_funcs_t *unicode,
1260 hb_bool_t mirror,
1261 hb_codepoint_t u,
1262 hb_set_t *glyphs)
1263 {
1264 hb_codepoint_t glyph;
1265 if (font->get_nominal_glyph (u, &glyph))
1266 glyphs->add (glyph);
1267 if (mirror)
1268 {
1269 hb_codepoint_t m = unicode->mirroring (u);
1270 if (m != u && font->get_nominal_glyph (m, &glyph))
1271 glyphs->add (glyph);
1272 }
1273 }
1274
1275
1276 /**
1277 * hb_ot_shape_glyphs_closure:
1278 * @font: #hb_font_t to work upon
1279 * @buffer: The input buffer to compute from
1280 * @features: (array length=num_features): The features enabled on the buffer
1281 * @num_features: The number of features enabled on the buffer
1282 * @glyphs: (out): The #hb_set_t set of glyphs comprising the transitive closure of the query
1283 *
1284 * Computes the transitive closure of glyphs needed for a specified
1285 * input buffer under the given font and feature list. The closure is
1286 * computed as a set, not as a list.
1287 *
1288 * Since: 0.9.2
1289 **/
1290 void
hb_ot_shape_glyphs_closure(hb_font_t * font,hb_buffer_t * buffer,const hb_feature_t * features,unsigned int num_features,hb_set_t * glyphs)1291 hb_ot_shape_glyphs_closure (hb_font_t *font,
1292 hb_buffer_t *buffer,
1293 const hb_feature_t *features,
1294 unsigned int num_features,
1295 hb_set_t *glyphs)
1296 {
1297 const char *shapers[] = {"ot", nullptr};
1298 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
1299 features, num_features, shapers);
1300
1301 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
1302
1303 unsigned int count = buffer->len;
1304 hb_glyph_info_t *info = buffer->info;
1305 for (unsigned int i = 0; i < count; i++)
1306 add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
1307
1308 hb_set_t *lookups = hb_set_create ();
1309 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, lookups);
1310 hb_ot_layout_lookups_substitute_closure (font->face, lookups, glyphs);
1311
1312 hb_set_destroy (lookups);
1313
1314 hb_shape_plan_destroy (shape_plan);
1315 }
1316
1317
1318 #endif
1319