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-shape-complex.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
51 /**
52 * SECTION:hb-ot-shape
53 * @title: hb-ot-shape
54 * @short_description: OpenType shaping support
55 * @include: hb-ot.h
56 *
57 * Support functions for OpenType shaping related queries.
58 **/
59
60
61 static void
62 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
63 const hb_feature_t *user_features,
64 unsigned int num_user_features);
65
66 #ifndef HB_NO_AAT_SHAPE
67 static inline bool
_hb_apply_morx(hb_face_t * face)68 _hb_apply_morx (hb_face_t *face)
69 {
70 if (hb_options ().aat &&
71 hb_aat_layout_has_substitution (face))
72 return true;
73
74 /* Ignore empty GSUB tables. */
75 return (!hb_ot_layout_has_substitution (face) ||
76 !hb_ot_layout_table_get_script_tags (face,
77 HB_OT_TAG_GSUB,
78 0, nullptr, nullptr)) &&
79 hb_aat_layout_has_substitution (face);
80 }
81 #endif
82
hb_ot_shape_planner_t(hb_face_t * face,const hb_segment_properties_t * props)83 hb_ot_shape_planner_t::hb_ot_shape_planner_t (hb_face_t *face,
84 const hb_segment_properties_t *props) :
85 face (face),
86 props (*props),
87 map (face, props),
88 aat_map (face, props)
89 #ifndef HB_NO_AAT_SHAPE
90 , apply_morx (_hb_apply_morx (face))
91 #endif
92 {
93 shaper = hb_ot_shape_complex_categorize (this);
94
95 script_zero_marks = shaper->zero_width_marks != HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE;
96 script_fallback_mark_positioning = shaper->fallback_position;
97
98 if (apply_morx)
99 shaper = &_hb_ot_complex_shaper_default;
100 }
101
102 void
compile(hb_ot_shape_plan_t & plan,const hb_ot_shape_plan_key_t & key)103 hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t &plan,
104 const hb_ot_shape_plan_key_t &key)
105 {
106 plan.props = props;
107 plan.shaper = shaper;
108 map.compile (plan.map, key);
109 #ifndef HB_NO_AAT_SHAPE
110 if (apply_morx)
111 aat_map.compile (plan.aat_map);
112 #endif
113
114 #ifndef HB_NO_OT_SHAPE_FRACTIONS
115 plan.frac_mask = plan.map.get_1_mask (HB_TAG ('f','r','a','c'));
116 plan.numr_mask = plan.map.get_1_mask (HB_TAG ('n','u','m','r'));
117 plan.dnom_mask = plan.map.get_1_mask (HB_TAG ('d','n','o','m'));
118 plan.has_frac = plan.frac_mask || (plan.numr_mask && plan.dnom_mask);
119 #endif
120
121 plan.rtlm_mask = plan.map.get_1_mask (HB_TAG ('r','t','l','m'));
122 hb_tag_t kern_tag = HB_DIRECTION_IS_HORIZONTAL (props.direction) ?
123 HB_TAG ('k','e','r','n') : HB_TAG ('v','k','r','n');
124 #ifndef HB_NO_OT_KERN
125 plan.kern_mask = plan.map.get_mask (kern_tag);
126 plan.requested_kerning = !!plan.kern_mask;
127 #endif
128 #ifndef HB_NO_AAT_SHAPE
129 plan.trak_mask = plan.map.get_mask (HB_TAG ('t','r','a','k'));
130 plan.requested_tracking = !!plan.trak_mask;
131 #endif
132
133 bool has_gpos_kern = plan.map.get_feature_index (1, kern_tag) != HB_OT_LAYOUT_NO_FEATURE_INDEX;
134 bool disable_gpos = plan.shaper->gpos_tag &&
135 plan.shaper->gpos_tag != plan.map.chosen_script[1];
136
137 /*
138 * Decide who provides glyph classes. GDEF or Unicode.
139 */
140
141 if (!hb_ot_layout_has_glyph_classes (face))
142 plan.fallback_glyph_classes = true;
143
144 /*
145 * Decide who does substitutions. GSUB, morx, or fallback.
146 */
147
148 #ifndef HB_NO_AAT_SHAPE
149 plan.apply_morx = apply_morx;
150 #endif
151
152 /*
153 * Decide who does positioning. GPOS, kerx, kern, or fallback.
154 */
155
156 if (0)
157 ;
158 #ifndef HB_NO_AAT_SHAPE
159 else if (hb_options ().aat && hb_aat_layout_has_positioning (face))
160 plan.apply_kerx = true;
161 #endif
162 else if (!apply_morx && !disable_gpos && hb_ot_layout_has_positioning (face))
163 plan.apply_gpos = true;
164 #ifndef HB_NO_AAT_SHAPE
165 else if (hb_aat_layout_has_positioning (face))
166 plan.apply_kerx = true;
167 #endif
168
169 if (!plan.apply_kerx && !has_gpos_kern)
170 {
171 /* Apparently Apple applies kerx if GPOS kern was not applied. */
172 #ifndef HB_NO_AAT_SHAPE
173 if (hb_aat_layout_has_positioning (face))
174 plan.apply_kerx = true;
175 else
176 #endif
177 #ifndef HB_NO_OT_KERN
178 if (hb_ot_layout_has_kerning (face))
179 plan.apply_kern = true;
180 #endif
181 }
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 /* Currently we always apply trak. */
205 plan.apply_trak = plan.requested_tracking && hb_aat_layout_has_tracking (face);
206 #endif
207 }
208
209 bool
init0(hb_face_t * face,const hb_shape_plan_key_t * key)210 hb_ot_shape_plan_t::init0 (hb_face_t *face,
211 const hb_shape_plan_key_t *key)
212 {
213 map.init ();
214 #ifndef HB_NO_AAT_SHAPE
215 aat_map.init ();
216 #endif
217
218 hb_ot_shape_planner_t planner (face,
219 &key->props);
220
221 hb_ot_shape_collect_features (&planner,
222 key->user_features,
223 key->num_user_features);
224
225 planner.compile (*this, key->ot);
226
227 if (shaper->data_create)
228 {
229 data = shaper->data_create (this);
230 if (unlikely (!data))
231 return false;
232 }
233
234 return true;
235 }
236
237 void
fini()238 hb_ot_shape_plan_t::fini ()
239 {
240 if (shaper->data_destroy)
241 shaper->data_destroy (const_cast<void *> (data));
242
243 map.fini ();
244 #ifndef HB_NO_AAT_SHAPE
245 aat_map.fini ();
246 #endif
247 }
248
249 void
substitute(hb_font_t * font,hb_buffer_t * buffer) const250 hb_ot_shape_plan_t::substitute (hb_font_t *font,
251 hb_buffer_t *buffer) const
252 {
253 #ifndef HB_NO_AAT_SHAPE
254 if (unlikely (apply_morx))
255 hb_aat_layout_substitute (this, font, buffer);
256 else
257 #endif
258 map.substitute (this, font, buffer);
259 }
260
261 void
position(hb_font_t * font,hb_buffer_t * buffer) const262 hb_ot_shape_plan_t::position (hb_font_t *font,
263 hb_buffer_t *buffer) const
264 {
265 if (this->apply_gpos)
266 map.position (this, font, buffer);
267 #ifndef HB_NO_AAT_SHAPE
268 else if (this->apply_kerx)
269 hb_aat_layout_position (this, font, buffer);
270 #endif
271 #ifndef HB_NO_OT_KERN
272 else if (this->apply_kern)
273 hb_ot_layout_kern (this, font, buffer);
274 #endif
275 else
276 _hb_ot_shape_fallback_kern (this, font, buffer);
277
278 #ifndef HB_NO_AAT_SHAPE
279 if (this->apply_trak)
280 hb_aat_layout_track (this, font, buffer);
281 #endif
282 }
283
284
285 static const hb_ot_map_feature_t
286 common_features[] =
287 {
288 {HB_TAG('a','b','v','m'), F_GLOBAL},
289 {HB_TAG('b','l','w','m'), F_GLOBAL},
290 {HB_TAG('c','c','m','p'), F_GLOBAL},
291 {HB_TAG('l','o','c','l'), F_GLOBAL},
292 {HB_TAG('m','a','r','k'), F_GLOBAL_MANUAL_JOINERS},
293 {HB_TAG('m','k','m','k'), F_GLOBAL_MANUAL_JOINERS},
294 {HB_TAG('r','l','i','g'), F_GLOBAL},
295 };
296
297
298 static const hb_ot_map_feature_t
299 horizontal_features[] =
300 {
301 {HB_TAG('c','a','l','t'), F_GLOBAL},
302 {HB_TAG('c','l','i','g'), F_GLOBAL},
303 {HB_TAG('c','u','r','s'), F_GLOBAL},
304 {HB_TAG('d','i','s','t'), F_GLOBAL},
305 {HB_TAG('k','e','r','n'), F_GLOBAL_HAS_FALLBACK},
306 {HB_TAG('l','i','g','a'), F_GLOBAL},
307 {HB_TAG('r','c','l','t'), F_GLOBAL},
308 };
309
310 static void
hb_ot_shape_collect_features(hb_ot_shape_planner_t * planner,const hb_feature_t * user_features,unsigned int num_user_features)311 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
312 const hb_feature_t *user_features,
313 unsigned int num_user_features)
314 {
315 hb_ot_map_builder_t *map = &planner->map;
316
317 map->enable_feature (HB_TAG('r','v','r','n'));
318 map->add_gsub_pause (nullptr);
319
320 switch (planner->props.direction) {
321 case HB_DIRECTION_LTR:
322 map->enable_feature (HB_TAG ('l','t','r','a'));
323 map->enable_feature (HB_TAG ('l','t','r','m'));
324 break;
325 case HB_DIRECTION_RTL:
326 map->enable_feature (HB_TAG ('r','t','l','a'));
327 map->add_feature (HB_TAG ('r','t','l','m'));
328 break;
329 case HB_DIRECTION_TTB:
330 case HB_DIRECTION_BTT:
331 case HB_DIRECTION_INVALID:
332 default:
333 break;
334 }
335
336 #ifndef HB_NO_OT_SHAPE_FRACTIONS
337 /* Automatic fractions. */
338 map->add_feature (HB_TAG ('f','r','a','c'));
339 map->add_feature (HB_TAG ('n','u','m','r'));
340 map->add_feature (HB_TAG ('d','n','o','m'));
341 #endif
342
343 /* Random! */
344 map->enable_feature (HB_TAG ('r','a','n','d'), F_RANDOM, HB_OT_MAP_MAX_VALUE);
345
346 #ifndef HB_NO_AAT_SHAPE
347 /* Tracking. We enable dummy feature here just to allow disabling
348 * AAT 'trak' table using features.
349 * https://github.com/harfbuzz/harfbuzz/issues/1303 */
350 map->enable_feature (HB_TAG ('t','r','a','k'), F_HAS_FALLBACK);
351 #endif
352
353 map->enable_feature (HB_TAG ('H','A','R','F'));
354
355 if (planner->shaper->collect_features)
356 planner->shaper->collect_features (planner);
357
358 map->enable_feature (HB_TAG ('B','U','Z','Z'));
359
360 for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
361 map->add_feature (common_features[i]);
362
363 if (HB_DIRECTION_IS_HORIZONTAL (planner->props.direction))
364 for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
365 map->add_feature (horizontal_features[i]);
366 else
367 {
368 /* We really want to find a 'vert' feature if there's any in the font, no
369 * matter which script/langsys it is listed (or not) under.
370 * See various bugs referenced from:
371 * https://github.com/harfbuzz/harfbuzz/issues/63 */
372 map->enable_feature (HB_TAG ('v','e','r','t'), F_GLOBAL_SEARCH);
373 }
374
375 for (unsigned int i = 0; i < num_user_features; i++)
376 {
377 const hb_feature_t *feature = &user_features[i];
378 map->add_feature (feature->tag,
379 (feature->start == HB_FEATURE_GLOBAL_START &&
380 feature->end == HB_FEATURE_GLOBAL_END) ? F_GLOBAL : F_NONE,
381 feature->value);
382 }
383
384 #ifndef HB_NO_AAT_SHAPE
385 if (planner->apply_morx)
386 {
387 hb_aat_map_builder_t *aat_map = &planner->aat_map;
388 for (unsigned int i = 0; i < num_user_features; i++)
389 {
390 const hb_feature_t *feature = &user_features[i];
391 aat_map->add_feature (feature->tag, feature->value);
392 }
393 }
394 #endif
395
396 if (planner->shaper->override_features)
397 planner->shaper->override_features (planner);
398 }
399
400
401 /*
402 * shaper face data
403 */
404
405 struct hb_ot_face_data_t {};
406
407 hb_ot_face_data_t *
_hb_ot_shaper_face_data_create(hb_face_t * face)408 _hb_ot_shaper_face_data_create (hb_face_t *face)
409 {
410 return (hb_ot_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
411 }
412
413 void
_hb_ot_shaper_face_data_destroy(hb_ot_face_data_t * data)414 _hb_ot_shaper_face_data_destroy (hb_ot_face_data_t *data)
415 {
416 }
417
418
419 /*
420 * shaper font data
421 */
422
423 struct hb_ot_font_data_t {};
424
425 hb_ot_font_data_t *
_hb_ot_shaper_font_data_create(hb_font_t * font HB_UNUSED)426 _hb_ot_shaper_font_data_create (hb_font_t *font HB_UNUSED)
427 {
428 return (hb_ot_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
429 }
430
431 void
_hb_ot_shaper_font_data_destroy(hb_ot_font_data_t * data HB_UNUSED)432 _hb_ot_shaper_font_data_destroy (hb_ot_font_data_t *data HB_UNUSED)
433 {
434 }
435
436
437 /*
438 * shaper
439 */
440
441 struct hb_ot_shape_context_t
442 {
443 hb_ot_shape_plan_t *plan;
444 hb_font_t *font;
445 hb_face_t *face;
446 hb_buffer_t *buffer;
447 const hb_feature_t *user_features;
448 unsigned int num_user_features;
449
450 /* Transient stuff */
451 hb_direction_t target_direction;
452 };
453
454
455
456 /* Main shaper */
457
458
459 /* Prepare */
460
461 static void
hb_set_unicode_props(hb_buffer_t * buffer)462 hb_set_unicode_props (hb_buffer_t *buffer)
463 {
464 /* Implement enough of Unicode Graphemes here that shaping
465 * in reverse-direction wouldn't break graphemes. Namely,
466 * we mark all marks and ZWJ and ZWJ,Extended_Pictographic
467 * sequences as continuations. The foreach_grapheme()
468 * macro uses this bit.
469 *
470 * https://www.unicode.org/reports/tr29/#Regex_Definitions
471 */
472 unsigned int count = buffer->len;
473 hb_glyph_info_t *info = buffer->info;
474 for (unsigned int i = 0; i < count; i++)
475 {
476 _hb_glyph_info_set_unicode_props (&info[i], buffer);
477
478 /* Marks are already set as continuation by the above line.
479 * Handle Emoji_Modifier and ZWJ-continuation. */
480 if (unlikely (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL &&
481 hb_in_range<hb_codepoint_t> (info[i].codepoint, 0x1F3FBu, 0x1F3FFu)))
482 {
483 _hb_glyph_info_set_continuation (&info[i]);
484 }
485 #ifndef HB_NO_EMOJI_SEQUENCES
486 else if (unlikely (_hb_glyph_info_is_zwj (&info[i])))
487 {
488 _hb_glyph_info_set_continuation (&info[i]);
489 if (i + 1 < count &&
490 _hb_unicode_is_emoji_Extended_Pictographic (info[i + 1].codepoint))
491 {
492 i++;
493 _hb_glyph_info_set_unicode_props (&info[i], buffer);
494 _hb_glyph_info_set_continuation (&info[i]);
495 }
496 }
497 #endif
498 /* Or part of the Other_Grapheme_Extend that is not marks.
499 * As of Unicode 11 that is just:
500 *
501 * 200C ; Other_Grapheme_Extend # Cf ZERO WIDTH NON-JOINER
502 * FF9E..FF9F ; Other_Grapheme_Extend # Lm [2] HALFWIDTH KATAKANA VOICED SOUND MARK..HALFWIDTH KATAKANA SEMI-VOICED SOUND MARK
503 * E0020..E007F ; Other_Grapheme_Extend # Cf [96] TAG SPACE..CANCEL TAG
504 *
505 * ZWNJ is special, we don't want to merge it as there's no need, and keeping
506 * it separate results in more granular clusters. Ignore Katakana for now.
507 * Tags are used for Emoji sub-region flag sequences:
508 * https://github.com/harfbuzz/harfbuzz/issues/1556
509 */
510 else if (unlikely (hb_in_range<hb_codepoint_t> (info[i].codepoint, 0xE0020u, 0xE007Fu)))
511 _hb_glyph_info_set_continuation (&info[i]);
512 }
513 }
514
515 static void
hb_insert_dotted_circle(hb_buffer_t * buffer,hb_font_t * font)516 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
517 {
518 if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
519 return;
520
521 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
522 buffer->context_len[0] ||
523 !_hb_glyph_info_is_unicode_mark (&buffer->info[0]))
524 return;
525
526 if (!font->has_glyph (0x25CCu))
527 return;
528
529 hb_glyph_info_t dottedcircle = {0};
530 dottedcircle.codepoint = 0x25CCu;
531 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer);
532
533 buffer->clear_output ();
534
535 buffer->idx = 0;
536 hb_glyph_info_t info = dottedcircle;
537 info.cluster = buffer->cur().cluster;
538 info.mask = buffer->cur().mask;
539 buffer->output_info (info);
540 while (buffer->idx < buffer->len && buffer->successful)
541 buffer->next_glyph ();
542 buffer->swap_buffers ();
543 }
544
545 static void
hb_form_clusters(hb_buffer_t * buffer)546 hb_form_clusters (hb_buffer_t *buffer)
547 {
548 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII))
549 return;
550
551 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
552 foreach_grapheme (buffer, start, end)
553 buffer->merge_clusters (start, end);
554 else
555 foreach_grapheme (buffer, start, end)
556 buffer->unsafe_to_break (start, end);
557 }
558
559 static void
hb_ensure_native_direction(hb_buffer_t * buffer)560 hb_ensure_native_direction (hb_buffer_t *buffer)
561 {
562 hb_direction_t direction = buffer->props.direction;
563 hb_direction_t horiz_dir = hb_script_get_horizontal_direction (buffer->props.script);
564
565 /* TODO vertical:
566 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
567 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
568 * first. */
569 if ((HB_DIRECTION_IS_HORIZONTAL (direction) &&
570 direction != horiz_dir && horiz_dir != HB_DIRECTION_INVALID) ||
571 (HB_DIRECTION_IS_VERTICAL (direction) &&
572 direction != HB_DIRECTION_TTB))
573 {
574
575 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
576 foreach_grapheme (buffer, start, end)
577 {
578 buffer->merge_clusters (start, end);
579 buffer->reverse_range (start, end);
580 }
581 else
582 foreach_grapheme (buffer, start, end)
583 /* form_clusters() merged clusters already, we don't merge. */
584 buffer->reverse_range (start, end);
585
586 buffer->reverse ();
587
588 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
589 }
590 }
591
592
593 /*
594 * Substitute
595 */
596
597 static inline void
hb_ot_mirror_chars(const hb_ot_shape_context_t * c)598 hb_ot_mirror_chars (const hb_ot_shape_context_t *c)
599 {
600 if (HB_DIRECTION_IS_FORWARD (c->target_direction))
601 return;
602
603 hb_buffer_t *buffer = c->buffer;
604 hb_unicode_funcs_t *unicode = buffer->unicode;
605 hb_mask_t rtlm_mask = c->plan->rtlm_mask;
606
607 unsigned int count = buffer->len;
608 hb_glyph_info_t *info = buffer->info;
609 for (unsigned int i = 0; i < count; i++) {
610 hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
611 if (likely (codepoint == info[i].codepoint || !c->font->has_glyph (codepoint)))
612 info[i].mask |= rtlm_mask;
613 else
614 info[i].codepoint = codepoint;
615 }
616 }
617
618 static inline void
hb_ot_shape_setup_masks_fraction(const hb_ot_shape_context_t * c)619 hb_ot_shape_setup_masks_fraction (const hb_ot_shape_context_t *c)
620 {
621 #ifdef HB_NO_OT_SHAPE_FRACTIONS
622 return;
623 #endif
624
625 if (!(c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_NON_ASCII) ||
626 !c->plan->has_frac)
627 return;
628
629 hb_buffer_t *buffer = c->buffer;
630
631 hb_mask_t pre_mask, post_mask;
632 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
633 {
634 pre_mask = c->plan->numr_mask | c->plan->frac_mask;
635 post_mask = c->plan->frac_mask | c->plan->dnom_mask;
636 }
637 else
638 {
639 pre_mask = c->plan->frac_mask | c->plan->dnom_mask;
640 post_mask = c->plan->numr_mask | c->plan->frac_mask;
641 }
642
643 unsigned int count = buffer->len;
644 hb_glyph_info_t *info = buffer->info;
645 for (unsigned int i = 0; i < count; i++)
646 {
647 if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
648 {
649 unsigned int start = i, end = i + 1;
650 while (start &&
651 _hb_glyph_info_get_general_category (&info[start - 1]) ==
652 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
653 start--;
654 while (end < count &&
655 _hb_glyph_info_get_general_category (&info[end]) ==
656 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
657 end++;
658
659 buffer->unsafe_to_break (start, end);
660
661 for (unsigned int j = start; j < i; j++)
662 info[j].mask |= pre_mask;
663 info[i].mask |= c->plan->frac_mask;
664 for (unsigned int j = i + 1; j < end; j++)
665 info[j].mask |= post_mask;
666
667 i = end - 1;
668 }
669 }
670 }
671
672 static inline void
hb_ot_shape_initialize_masks(const hb_ot_shape_context_t * c)673 hb_ot_shape_initialize_masks (const hb_ot_shape_context_t *c)
674 {
675 hb_ot_map_t *map = &c->plan->map;
676 hb_buffer_t *buffer = c->buffer;
677
678 hb_mask_t global_mask = map->get_global_mask ();
679 buffer->reset_masks (global_mask);
680 }
681
682 static inline void
hb_ot_shape_setup_masks(const hb_ot_shape_context_t * c)683 hb_ot_shape_setup_masks (const hb_ot_shape_context_t *c)
684 {
685 hb_ot_map_t *map = &c->plan->map;
686 hb_buffer_t *buffer = c->buffer;
687
688 hb_ot_shape_setup_masks_fraction (c);
689
690 if (c->plan->shaper->setup_masks)
691 c->plan->shaper->setup_masks (c->plan, buffer, c->font);
692
693 for (unsigned int i = 0; i < c->num_user_features; i++)
694 {
695 const hb_feature_t *feature = &c->user_features[i];
696 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
697 unsigned int shift;
698 hb_mask_t mask = map->get_mask (feature->tag, &shift);
699 buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
700 }
701 }
702 }
703
704 static void
hb_ot_zero_width_default_ignorables(const hb_buffer_t * buffer)705 hb_ot_zero_width_default_ignorables (const hb_buffer_t *buffer)
706 {
707 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
708 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) ||
709 (buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES))
710 return;
711
712 unsigned int count = buffer->len;
713 hb_glyph_info_t *info = buffer->info;
714 hb_glyph_position_t *pos = buffer->pos;
715 unsigned int i = 0;
716 for (i = 0; i < count; i++)
717 if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
718 pos[i].x_advance = pos[i].y_advance = pos[i].x_offset = pos[i].y_offset = 0;
719 }
720
721 static void
hb_ot_hide_default_ignorables(hb_buffer_t * buffer,hb_font_t * font)722 hb_ot_hide_default_ignorables (hb_buffer_t *buffer,
723 hb_font_t *font)
724 {
725 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_DEFAULT_IGNORABLES) ||
726 (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES))
727 return;
728
729 unsigned int count = buffer->len;
730 hb_glyph_info_t *info = buffer->info;
731
732 hb_codepoint_t invisible = buffer->invisible;
733 if (!(buffer->flags & HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES) &&
734 (invisible || font->get_nominal_glyph (' ', &invisible)))
735 {
736 /* Replace default-ignorables with a zero-advance invisible glyph. */
737 for (unsigned int i = 0; i < count; i++)
738 {
739 if (_hb_glyph_info_is_default_ignorable (&info[i]))
740 info[i].codepoint = invisible;
741 }
742 }
743 else
744 hb_ot_layout_delete_glyphs_inplace (buffer, _hb_glyph_info_is_default_ignorable);
745 }
746
747
748 static inline void
hb_ot_map_glyphs_fast(hb_buffer_t * buffer)749 hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
750 {
751 /* Normalization process sets up glyph_index(), we just copy it. */
752 unsigned int count = buffer->len;
753 hb_glyph_info_t *info = buffer->info;
754 for (unsigned int i = 0; i < count; i++)
755 info[i].codepoint = info[i].glyph_index();
756
757 buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
758 }
759
760 static inline void
hb_synthesize_glyph_classes(hb_buffer_t * buffer)761 hb_synthesize_glyph_classes (hb_buffer_t *buffer)
762 {
763 unsigned int count = buffer->len;
764 hb_glyph_info_t *info = buffer->info;
765 for (unsigned int i = 0; i < count; i++)
766 {
767 hb_ot_layout_glyph_props_flags_t klass;
768
769 /* Never mark default-ignorables as marks.
770 * They won't get in the way of lookups anyway,
771 * but having them as mark will cause them to be skipped
772 * over if the lookup-flag says so, but at least for the
773 * Mongolian variation selectors, looks like Uniscribe
774 * marks them as non-mark. Some Mongolian fonts without
775 * GDEF rely on this. Another notable character that
776 * this applies to is COMBINING GRAPHEME JOINER. */
777 klass = (_hb_glyph_info_get_general_category (&info[i]) !=
778 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
779 _hb_glyph_info_is_default_ignorable (&info[i])) ?
780 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
781 HB_OT_LAYOUT_GLYPH_PROPS_MARK;
782 _hb_glyph_info_set_glyph_props (&info[i], klass);
783 }
784 }
785
786 static inline void
hb_ot_substitute_default(const hb_ot_shape_context_t * c)787 hb_ot_substitute_default (const hb_ot_shape_context_t *c)
788 {
789 hb_buffer_t *buffer = c->buffer;
790
791 hb_ot_mirror_chars (c);
792
793 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
794
795 _hb_ot_shape_normalize (c->plan, buffer, c->font);
796
797 hb_ot_shape_setup_masks (c);
798
799 /* This is unfortunate to go here, but necessary... */
800 if (c->plan->fallback_mark_positioning)
801 _hb_ot_shape_fallback_mark_position_recategorize_marks (c->plan, c->font, buffer);
802
803 hb_ot_map_glyphs_fast (buffer);
804
805 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
806 }
807
808 static inline void
hb_ot_substitute_complex(const hb_ot_shape_context_t * c)809 hb_ot_substitute_complex (const hb_ot_shape_context_t *c)
810 {
811 hb_buffer_t *buffer = c->buffer;
812
813 hb_ot_layout_substitute_start (c->font, buffer);
814
815 if (c->plan->fallback_glyph_classes)
816 hb_synthesize_glyph_classes (c->buffer);
817
818 c->plan->substitute (c->font, buffer);
819 }
820
821 static inline void
hb_ot_substitute_pre(const hb_ot_shape_context_t * c)822 hb_ot_substitute_pre (const hb_ot_shape_context_t *c)
823 {
824 hb_ot_substitute_default (c);
825
826 _hb_buffer_allocate_gsubgpos_vars (c->buffer);
827
828 hb_ot_substitute_complex (c);
829 }
830
831 static inline void
hb_ot_substitute_post(const hb_ot_shape_context_t * c)832 hb_ot_substitute_post (const hb_ot_shape_context_t *c)
833 {
834 hb_ot_hide_default_ignorables (c->buffer, c->font);
835 #ifndef HB_NO_AAT_SHAPE
836 if (c->plan->apply_morx)
837 hb_aat_layout_remove_deleted_glyphs (c->buffer);
838 #endif
839
840 if (c->plan->shaper->postprocess_glyphs)
841 c->plan->shaper->postprocess_glyphs (c->plan, c->buffer, c->font);
842 }
843
844
845 /*
846 * Position
847 */
848
849 static inline void
adjust_mark_offsets(hb_glyph_position_t * pos)850 adjust_mark_offsets (hb_glyph_position_t *pos)
851 {
852 pos->x_offset -= pos->x_advance;
853 pos->y_offset -= pos->y_advance;
854 }
855
856 static inline void
zero_mark_width(hb_glyph_position_t * pos)857 zero_mark_width (hb_glyph_position_t *pos)
858 {
859 pos->x_advance = 0;
860 pos->y_advance = 0;
861 }
862
863 static inline void
zero_mark_widths_by_gdef(hb_buffer_t * buffer,bool adjust_offsets)864 zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
865 {
866 unsigned int count = buffer->len;
867 hb_glyph_info_t *info = buffer->info;
868 for (unsigned int i = 0; i < count; i++)
869 if (_hb_glyph_info_is_mark (&info[i]))
870 {
871 if (adjust_offsets)
872 adjust_mark_offsets (&buffer->pos[i]);
873 zero_mark_width (&buffer->pos[i]);
874 }
875 }
876
877 static inline void
hb_ot_position_default(const hb_ot_shape_context_t * c)878 hb_ot_position_default (const hb_ot_shape_context_t *c)
879 {
880 hb_direction_t direction = c->buffer->props.direction;
881 unsigned int count = c->buffer->len;
882 hb_glyph_info_t *info = c->buffer->info;
883 hb_glyph_position_t *pos = c->buffer->pos;
884
885 if (HB_DIRECTION_IS_HORIZONTAL (direction))
886 {
887 c->font->get_glyph_h_advances (count, &info[0].codepoint, sizeof(info[0]),
888 &pos[0].x_advance, sizeof(pos[0]));
889 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
890 if (c->font->has_glyph_h_origin_func ())
891 for (unsigned int i = 0; i < count; i++)
892 c->font->subtract_glyph_h_origin (info[i].codepoint,
893 &pos[i].x_offset,
894 &pos[i].y_offset);
895 }
896 else
897 {
898 c->font->get_glyph_v_advances (count, &info[0].codepoint, sizeof(info[0]),
899 &pos[0].y_advance, sizeof(pos[0]));
900 for (unsigned int i = 0; i < count; i++)
901 {
902 c->font->subtract_glyph_v_origin (info[i].codepoint,
903 &pos[i].x_offset,
904 &pos[i].y_offset);
905 }
906 }
907 if (c->buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_SPACE_FALLBACK)
908 _hb_ot_shape_fallback_spaces (c->plan, c->font, c->buffer);
909 }
910
911 static inline void
hb_ot_position_complex(const hb_ot_shape_context_t * c)912 hb_ot_position_complex (const hb_ot_shape_context_t *c)
913 {
914 unsigned int count = c->buffer->len;
915 hb_glyph_info_t *info = c->buffer->info;
916 hb_glyph_position_t *pos = c->buffer->pos;
917
918 /* If the font has no GPOS and direction is forward, then when
919 * zeroing mark widths, we shift the mark with it, such that the
920 * mark is positioned hanging over the previous glyph. When
921 * direction is backward we don't shift and it will end up
922 * hanging over the next glyph after the final reordering.
923 *
924 * Note: If fallback positinoing happens, we don't care about
925 * this as it will be overriden.
926 */
927 bool adjust_offsets_when_zeroing = c->plan->adjust_mark_positioning_when_zeroing &&
928 HB_DIRECTION_IS_FORWARD (c->buffer->props.direction);
929
930 /* We change glyph origin to what GPOS expects (horizontal), apply GPOS, change it back. */
931
932 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
933 if (c->font->has_glyph_h_origin_func ())
934 for (unsigned int i = 0; i < count; i++)
935 c->font->add_glyph_h_origin (info[i].codepoint,
936 &pos[i].x_offset,
937 &pos[i].y_offset);
938
939 hb_ot_layout_position_start (c->font, c->buffer);
940
941 if (c->plan->zero_marks)
942 switch (c->plan->shaper->zero_width_marks)
943 {
944 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
945 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
946 break;
947
948 default:
949 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
950 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
951 break;
952 }
953
954 c->plan->position (c->font, c->buffer);
955
956 if (c->plan->zero_marks)
957 switch (c->plan->shaper->zero_width_marks)
958 {
959 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
960 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
961 break;
962
963 default:
964 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
965 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
966 break;
967 }
968
969 /* Finish off. Has to follow a certain order. */
970 hb_ot_layout_position_finish_advances (c->font, c->buffer);
971 hb_ot_zero_width_default_ignorables (c->buffer);
972 #ifndef HB_NO_AAT_SHAPE
973 if (c->plan->apply_morx)
974 hb_aat_layout_zero_width_deleted_glyphs (c->buffer);
975 #endif
976 hb_ot_layout_position_finish_offsets (c->font, c->buffer);
977
978 /* The nil glyph_h_origin() func returns 0, so no need to apply it. */
979 if (c->font->has_glyph_h_origin_func ())
980 for (unsigned int i = 0; i < count; i++)
981 c->font->subtract_glyph_h_origin (info[i].codepoint,
982 &pos[i].x_offset,
983 &pos[i].y_offset);
984
985 if (c->plan->fallback_mark_positioning)
986 _hb_ot_shape_fallback_mark_position (c->plan, c->font, c->buffer,
987 adjust_offsets_when_zeroing);
988 }
989
990 static inline void
hb_ot_position(const hb_ot_shape_context_t * c)991 hb_ot_position (const hb_ot_shape_context_t *c)
992 {
993 c->buffer->clear_positions ();
994
995 hb_ot_position_default (c);
996
997 hb_ot_position_complex (c);
998
999 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
1000 hb_buffer_reverse (c->buffer);
1001
1002 _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
1003 }
1004
1005 static inline void
hb_propagate_flags(hb_buffer_t * buffer)1006 hb_propagate_flags (hb_buffer_t *buffer)
1007 {
1008 /* Propagate cluster-level glyph flags to be the same on all cluster glyphs.
1009 * Simplifies using them. */
1010
1011 if (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_UNSAFE_TO_BREAK))
1012 return;
1013
1014 hb_glyph_info_t *info = buffer->info;
1015
1016 foreach_cluster (buffer, start, end)
1017 {
1018 unsigned int mask = 0;
1019 for (unsigned int i = start; i < end; i++)
1020 if (info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK)
1021 {
1022 mask = HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
1023 break;
1024 }
1025 if (mask)
1026 for (unsigned int i = start; i < end; i++)
1027 info[i].mask |= mask;
1028 }
1029 }
1030
1031 /* Pull it all together! */
1032
1033 static void
hb_ot_shape_internal(hb_ot_shape_context_t * c)1034 hb_ot_shape_internal (hb_ot_shape_context_t *c)
1035 {
1036 c->buffer->deallocate_var_all ();
1037 c->buffer->scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
1038 if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_LEN_FACTOR)))
1039 {
1040 c->buffer->max_len = hb_max (c->buffer->len * HB_BUFFER_MAX_LEN_FACTOR,
1041 (unsigned) HB_BUFFER_MAX_LEN_MIN);
1042 }
1043 if (likely (!hb_unsigned_mul_overflows (c->buffer->len, HB_BUFFER_MAX_OPS_FACTOR)))
1044 {
1045 c->buffer->max_ops = hb_max (c->buffer->len * HB_BUFFER_MAX_OPS_FACTOR,
1046 (unsigned) HB_BUFFER_MAX_OPS_MIN);
1047 }
1048
1049 /* Save the original direction, we use it later. */
1050 c->target_direction = c->buffer->props.direction;
1051
1052 _hb_buffer_allocate_unicode_vars (c->buffer);
1053
1054 c->buffer->clear_output ();
1055
1056 hb_ot_shape_initialize_masks (c);
1057 hb_set_unicode_props (c->buffer);
1058 hb_insert_dotted_circle (c->buffer, c->font);
1059
1060 hb_form_clusters (c->buffer);
1061
1062 hb_ensure_native_direction (c->buffer);
1063
1064 if (c->plan->shaper->preprocess_text)
1065 c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
1066
1067 hb_ot_substitute_pre (c);
1068 hb_ot_position (c);
1069 hb_ot_substitute_post (c);
1070
1071 hb_propagate_flags (c->buffer);
1072
1073 _hb_buffer_deallocate_unicode_vars (c->buffer);
1074
1075 c->buffer->props.direction = c->target_direction;
1076
1077 c->buffer->max_len = HB_BUFFER_MAX_LEN_DEFAULT;
1078 c->buffer->max_ops = HB_BUFFER_MAX_OPS_DEFAULT;
1079 c->buffer->deallocate_var_all ();
1080 }
1081
1082
1083 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)1084 _hb_ot_shape (hb_shape_plan_t *shape_plan,
1085 hb_font_t *font,
1086 hb_buffer_t *buffer,
1087 const hb_feature_t *features,
1088 unsigned int num_features)
1089 {
1090 hb_ot_shape_context_t c = {&shape_plan->ot, font, font->face, buffer, features, num_features};
1091 hb_ot_shape_internal (&c);
1092
1093 return true;
1094 }
1095
1096
1097 /**
1098 * hb_ot_shape_plan_collect_lookups:
1099 *
1100 * Since: 0.9.7
1101 **/
1102 void
hb_ot_shape_plan_collect_lookups(hb_shape_plan_t * shape_plan,hb_tag_t table_tag,hb_set_t * lookup_indexes)1103 hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
1104 hb_tag_t table_tag,
1105 hb_set_t *lookup_indexes /* OUT */)
1106 {
1107 shape_plan->ot.collect_lookups (table_tag, lookup_indexes);
1108 }
1109
1110
1111 /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
1112 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)1113 add_char (hb_font_t *font,
1114 hb_unicode_funcs_t *unicode,
1115 hb_bool_t mirror,
1116 hb_codepoint_t u,
1117 hb_set_t *glyphs)
1118 {
1119 hb_codepoint_t glyph;
1120 if (font->get_nominal_glyph (u, &glyph))
1121 glyphs->add (glyph);
1122 if (mirror)
1123 {
1124 hb_codepoint_t m = unicode->mirroring (u);
1125 if (m != u && font->get_nominal_glyph (m, &glyph))
1126 glyphs->add (glyph);
1127 }
1128 }
1129
1130
1131 /**
1132 * hb_ot_shape_glyphs_closure:
1133 *
1134 * Since: 0.9.2
1135 **/
1136 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)1137 hb_ot_shape_glyphs_closure (hb_font_t *font,
1138 hb_buffer_t *buffer,
1139 const hb_feature_t *features,
1140 unsigned int num_features,
1141 hb_set_t *glyphs)
1142 {
1143 const char *shapers[] = {"ot", nullptr};
1144 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
1145 features, num_features, shapers);
1146
1147 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
1148
1149 unsigned int count = buffer->len;
1150 hb_glyph_info_t *info = buffer->info;
1151 for (unsigned int i = 0; i < count; i++)
1152 add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
1153
1154 hb_set_t *lookups = hb_set_create ();
1155 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, lookups);
1156 hb_ot_layout_lookups_substitute_closure (font->face, lookups, glyphs);
1157
1158 hb_set_destroy (lookups);
1159
1160 hb_shape_plan_destroy (shape_plan);
1161 }
1162
1163
1164 #endif
1165