1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 // This file is available under and governed by the GNU General Public
26 // License version 2 only, as published by the Free Software Foundation.
27 // However, the following notice accompanied the original version of this
28 // file:
29 //
30 /*
31 * Copyright © 2009,2010 Red Hat, Inc.
32 * Copyright © 2010,2011,2012 Google, Inc.
33 *
34 * This is part of HarfBuzz, a text shaping library.
35 *
36 * Permission is hereby granted, without written agreement and without
37 * license or royalty fees, to use, copy, modify, and distribute this
38 * software and its documentation for any purpose, provided that the
39 * above copyright notice and the following two paragraphs appear in
40 * all copies of this software.
41 *
42 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
43 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
44 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
45 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
46 * DAMAGE.
47 *
48 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
49 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
50 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
51 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
52 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
53 *
54 * Red Hat Author(s): Behdad Esfahbod
55 * Google Author(s): Behdad Esfahbod
56 */
57
58 #define HB_SHAPER ot
59 #define hb_ot_shaper_face_data_t hb_ot_layout_t
60 #define hb_ot_shaper_shape_plan_data_t hb_ot_shape_plan_t
61 #include "hb-shaper-impl-private.hh"
62
63 #include "hb-ot-shape-private.hh"
64 #include "hb-ot-shape-complex-private.hh"
65 #include "hb-ot-shape-fallback-private.hh"
66 #include "hb-ot-shape-normalize-private.hh"
67
68 #include "hb-ot-layout-private.hh"
69 #include "hb-unicode-private.hh"
70 #include "hb-set-private.hh"
71
72
73 static hb_tag_t common_features[] = {
74 HB_TAG('c','c','m','p'),
75 HB_TAG('l','o','c','l'),
76 HB_TAG('m','a','r','k'),
77 HB_TAG('m','k','m','k'),
78 HB_TAG('r','l','i','g'),
79 };
80
81
82 static hb_tag_t horizontal_features[] = {
83 HB_TAG('c','a','l','t'),
84 HB_TAG('c','l','i','g'),
85 HB_TAG('c','u','r','s'),
86 HB_TAG('k','e','r','n'),
87 HB_TAG('l','i','g','a'),
88 HB_TAG('r','c','l','t'),
89 };
90
91
92
93 static void
94 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
95 const hb_segment_properties_t *props,
96 const hb_feature_t *user_features,
97 unsigned int num_user_features)
98 {
99 hb_ot_map_builder_t *map = &planner->map;
100
101 switch (props->direction) {
102 case HB_DIRECTION_LTR:
103 map->add_global_bool_feature (HB_TAG ('l','t','r','a'));
104 map->add_global_bool_feature (HB_TAG ('l','t','r','m'));
105 break;
106 case HB_DIRECTION_RTL:
107 map->add_global_bool_feature (HB_TAG ('r','t','l','a'));
108 map->add_feature (HB_TAG ('r','t','l','m'), 1, F_NONE);
109 break;
110 case HB_DIRECTION_TTB:
111 case HB_DIRECTION_BTT:
112 case HB_DIRECTION_INVALID:
113 default:
114 break;
115 }
116
117 map->add_feature (HB_TAG ('f','r','a','c'), 1, F_NONE);
118 map->add_feature (HB_TAG ('n','u','m','r'), 1, F_NONE);
119 map->add_feature (HB_TAG ('d','n','o','m'), 1, F_NONE);
120
121 if (planner->shaper->collect_features)
122 planner->shaper->collect_features (planner);
123
124 for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++)
125 map->add_global_bool_feature (common_features[i]);
126
127 if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
128 for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++)
129 map->add_feature (horizontal_features[i], 1, F_GLOBAL |
130 (horizontal_features[i] == HB_TAG('k','e','r','n') ?
131 F_HAS_FALLBACK : F_NONE));
132 else
133 {
134 /* We really want to find a 'vert' feature if there's any in the font, no
135 * matter which script/langsys it is listed (or not) under.
136 * See various bugs referenced from:
137 * https://github.com/behdad/harfbuzz/issues/63 */
138 map->add_feature (HB_TAG ('v','e','r','t'), 1, F_GLOBAL | F_GLOBAL_SEARCH);
139 }
140
141 if (planner->shaper->override_features)
142 planner->shaper->override_features (planner);
143
144 for (unsigned int i = 0; i < num_user_features; i++) {
145 const hb_feature_t *feature = &user_features[i];
146 map->add_feature (feature->tag, feature->value,
147 (feature->start == 0 && feature->end == (unsigned int) -1) ?
148 F_GLOBAL : F_NONE);
149 }
150 }
151
152
153 /*
154 * shaper face data
155 */
156
157 hb_ot_shaper_face_data_t *
158 _hb_ot_shaper_face_data_create (hb_face_t *face)
159 {
160 return _hb_ot_layout_create (face);
161 }
162
163 void
164 _hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data)
165 {
166 _hb_ot_layout_destroy (data);
167 }
168
169
170 /*
171 * shaper font data
172 */
173
174 struct hb_ot_shaper_font_data_t {};
175
176 hb_ot_shaper_font_data_t *
177 _hb_ot_shaper_font_data_create (hb_font_t *font)
178 {
179 return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
180 }
181
182 void
183 _hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data)
184 {
185 }
186
187
188 /*
189 * shaper shape_plan data
190 */
191
192 hb_ot_shaper_shape_plan_data_t *
193 _hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan,
194 const hb_feature_t *user_features,
195 unsigned int num_user_features)
196 {
197 hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t));
198 if (unlikely (!plan))
199 return NULL;
200
201 hb_ot_shape_planner_t planner (shape_plan);
202
203 planner.shaper = hb_ot_shape_complex_categorize (&planner);
204
205 hb_ot_shape_collect_features (&planner, &shape_plan->props, user_features, num_user_features);
206
207 planner.compile (*plan);
208
209 if (plan->shaper->data_create) {
210 plan->data = plan->shaper->data_create (plan);
211 if (unlikely (!plan->data))
212 return NULL;
213 }
214
215 return plan;
216 }
217
218 void
219 _hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan)
220 {
221 if (plan->shaper->data_destroy)
222 plan->shaper->data_destroy (const_cast<void *> (plan->data));
223
224 plan->finish ();
225
226 free (plan);
227 }
228
229
230 /*
231 * shaper
232 */
233
234 struct hb_ot_shape_context_t
235 {
236 hb_ot_shape_plan_t *plan;
237 hb_font_t *font;
238 hb_face_t *face;
239 hb_buffer_t *buffer;
240 const hb_feature_t *user_features;
241 unsigned int num_user_features;
242
243 /* Transient stuff */
244 hb_direction_t target_direction;
245 };
246
247
248
249 /* Main shaper */
250
251
252 /* Prepare */
253
254 static void
255 hb_set_unicode_props (hb_buffer_t *buffer)
256 {
257 unsigned int count = buffer->len;
258 hb_glyph_info_t *info = buffer->info;
259 for (unsigned int i = 0; i < count; i++)
260 _hb_glyph_info_set_unicode_props (&info[i], buffer->unicode);
261 }
262
263 static void
264 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
265 {
266 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
267 buffer->context_len[0] ||
268 _hb_glyph_info_get_general_category (&buffer->info[0]) !=
269 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
270 return;
271
272 if (!font->has_glyph (0x25CCu))
273 return;
274
275 hb_glyph_info_t dottedcircle = {0};
276 dottedcircle.codepoint = 0x25CCu;
277 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer->unicode);
278
279 buffer->clear_output ();
280
281 buffer->idx = 0;
282 hb_glyph_info_t info = dottedcircle;
283 info.cluster = buffer->cur().cluster;
284 info.mask = buffer->cur().mask;
285 buffer->output_info (info);
286 while (buffer->idx < buffer->len)
287 buffer->next_glyph ();
288
289 buffer->swap_buffers ();
290 }
291
292 static void
293 hb_form_clusters (hb_buffer_t *buffer)
294 {
295 if (buffer->cluster_level != HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
296 return;
297
298 /* Loop duplicated in hb_ensure_native_direction(). */
299 unsigned int base = 0;
300 unsigned int count = buffer->len;
301 hb_glyph_info_t *info = buffer->info;
302 for (unsigned int i = 1; i < count; i++)
303 {
304 if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i]))))
305 {
306 buffer->merge_clusters (base, i);
307 base = i;
308 }
309 }
310 buffer->merge_clusters (base, count);
311 }
312
313 static void
314 hb_ensure_native_direction (hb_buffer_t *buffer)
315 {
316 hb_direction_t direction = buffer->props.direction;
317
318 /* TODO vertical:
319 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
320 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
321 * first. */
322 if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) ||
323 (HB_DIRECTION_IS_VERTICAL (direction) && direction != HB_DIRECTION_TTB))
324 {
325 /* Same loop as hb_form_clusters().
326 * Since form_clusters() merged clusters already, we don't merge. */
327 unsigned int base = 0;
328 unsigned int count = buffer->len;
329 hb_glyph_info_t *info = buffer->info;
330 for (unsigned int i = 1; i < count; i++)
331 {
332 if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i]))))
333 {
334 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
335 buffer->merge_clusters (base, i);
336 buffer->reverse_range (base, i);
337
338 base = i;
339 }
340 }
341 if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS)
342 buffer->merge_clusters (base, count);
343 buffer->reverse_range (base, count);
344
345 buffer->reverse ();
346
347 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
348 }
349 }
350
351
352 /* Substitute */
353
354 static inline void
355 hb_ot_mirror_chars (hb_ot_shape_context_t *c)
356 {
357 if (HB_DIRECTION_IS_FORWARD (c->target_direction))
358 return;
359
360 hb_buffer_t *buffer = c->buffer;
361 hb_unicode_funcs_t *unicode = buffer->unicode;
362 hb_mask_t rtlm_mask = c->plan->rtlm_mask;
363
364 unsigned int count = buffer->len;
365 hb_glyph_info_t *info = buffer->info;
366 for (unsigned int i = 0; i < count; i++) {
367 hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint);
368 if (likely (codepoint == info[i].codepoint || !c->font->has_glyph (codepoint)))
369 info[i].mask |= rtlm_mask;
370 else
371 info[i].codepoint = codepoint;
372 }
373 }
374
375 static inline void
376 hb_ot_shape_setup_masks_fraction (hb_ot_shape_context_t *c)
377 {
378 if (!c->plan->has_frac)
379 return;
380
381 hb_buffer_t *buffer = c->buffer;
382
383 /* TODO look in pre/post context text also. */
384 unsigned int count = buffer->len;
385 hb_glyph_info_t *info = buffer->info;
386 for (unsigned int i = 0; i < count; i++)
387 {
388 if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */
389 {
390 unsigned int start = i, end = i + 1;
391 while (start &&
392 _hb_glyph_info_get_general_category (&info[start - 1]) ==
393 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
394 start--;
395 while (end < count &&
396 _hb_glyph_info_get_general_category (&info[end]) ==
397 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER)
398 end++;
399
400 for (unsigned int j = start; j < i; j++)
401 info[j].mask |= c->plan->numr_mask | c->plan->frac_mask;
402 info[i].mask |= c->plan->frac_mask;
403 for (unsigned int j = i + 1; j < end; j++)
404 info[j].mask |= c->plan->frac_mask | c->plan->dnom_mask;
405
406 i = end - 1;
407 }
408 }
409 }
410
411 static inline void
412 hb_ot_shape_initialize_masks (hb_ot_shape_context_t *c)
413 {
414 hb_ot_map_t *map = &c->plan->map;
415 hb_buffer_t *buffer = c->buffer;
416
417 hb_mask_t global_mask = map->get_global_mask ();
418 buffer->reset_masks (global_mask);
419 }
420
421 static inline void
422 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
423 {
424 hb_ot_map_t *map = &c->plan->map;
425 hb_buffer_t *buffer = c->buffer;
426
427 hb_ot_shape_setup_masks_fraction (c);
428
429 if (c->plan->shaper->setup_masks)
430 c->plan->shaper->setup_masks (c->plan, buffer, c->font);
431
432 for (unsigned int i = 0; i < c->num_user_features; i++)
433 {
434 const hb_feature_t *feature = &c->user_features[i];
435 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
436 unsigned int shift;
437 hb_mask_t mask = map->get_mask (feature->tag, &shift);
438 buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
439 }
440 }
441 }
442
443 static void
444 hb_ot_zero_width_default_ignorables (hb_ot_shape_context_t *c)
445 {
446 hb_buffer_t *buffer = c->buffer;
447
448 if (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES)
449 return;
450
451 unsigned int count = buffer->len;
452 hb_glyph_info_t *info = buffer->info;
453 hb_glyph_position_t *pos = buffer->pos;
454 unsigned int i = 0;
455 for (i = 0; i < count; i++)
456 if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
457 pos[i].x_advance = pos[i].y_advance = pos[i].x_offset = pos[i].y_offset = 0;
458 }
459
460 static void
461 hb_ot_hide_default_ignorables (hb_ot_shape_context_t *c)
462 {
463 hb_buffer_t *buffer = c->buffer;
464
465 if (buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES)
466 return;
467
468 unsigned int count = buffer->len;
469 hb_glyph_info_t *info = buffer->info;
470 hb_glyph_position_t *pos = buffer->pos;
471 unsigned int i = 0;
472 for (i = 0; i < count; i++)
473 {
474 if (unlikely (_hb_glyph_info_is_default_ignorable (&info[i])))
475 break;
476 }
477
478 /* No default-ignorables found; return. */
479 if (i == count)
480 return;
481
482 hb_codepoint_t space;
483 if (c->font->get_glyph (' ', 0, &space))
484 {
485 /* Replace default-ignorables with a zero-advance space glyph. */
486 for (/*continue*/; i < count; i++)
487 {
488 if (_hb_glyph_info_is_default_ignorable (&info[i]))
489 info[i].codepoint = space;
490 }
491 }
492 else
493 {
494 /* Merge clusters and delete default-ignorables.
495 * NOTE! We can't use out-buffer as we have positioning data. */
496 unsigned int j = i;
497 for (; i < count; i++)
498 {
499 if (_hb_glyph_info_is_default_ignorable (&info[i]))
500 {
501 /* Merge clusters.
502 * Same logic as buffer->delete_glyph(), but for in-place removal. */
503
504 unsigned int cluster = info[i].cluster;
505 if (i + 1 < count && cluster == info[i + 1].cluster)
506 continue; /* Cluster survives; do nothing. */
507
508 if (j)
509 {
510 /* Merge cluster backward. */
511 if (cluster < info[j - 1].cluster)
512 {
513 unsigned int old_cluster = info[j - 1].cluster;
514 for (unsigned k = j; k && info[k - 1].cluster == old_cluster; k--)
515 info[k - 1].cluster = cluster;
516 }
517 continue;
518 }
519
520 if (i + 1 < count)
521 buffer->merge_clusters (i, i + 2); /* Merge cluster forward. */
522
523 continue;
524 }
525
526 if (j != i)
527 {
528 info[j] = info[i];
529 pos[j] = pos[i];
530 }
531 j++;
532 }
533 buffer->len = j;
534 }
535 }
536
537
538 static inline void
539 hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
540 {
541 /* Normalization process sets up glyph_index(), we just copy it. */
542 unsigned int count = buffer->len;
543 hb_glyph_info_t *info = buffer->info;
544 for (unsigned int i = 0; i < count; i++)
545 info[i].codepoint = info[i].glyph_index();
546
547 buffer->content_type = HB_BUFFER_CONTENT_TYPE_GLYPHS;
548 }
549
550 static inline void
551 hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
552 {
553 unsigned int count = c->buffer->len;
554 hb_glyph_info_t *info = c->buffer->info;
555 for (unsigned int i = 0; i < count; i++)
556 {
557 hb_ot_layout_glyph_class_mask_t klass;
558
559 /* Never mark default-ignorables as marks.
560 * They won't get in the way of lookups anyway,
561 * but having them as mark will cause them to be skipped
562 * over if the lookup-flag says so, but at least for the
563 * Mongolian variation selectors, looks like Uniscribe
564 * marks them as non-mark. Some Mongolian fonts without
565 * GDEF rely on this. Another notable character that
566 * this applies to is COMBINING GRAPHEME JOINER. */
567 klass = (_hb_glyph_info_get_general_category (&info[i]) !=
568 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ||
569 _hb_glyph_info_is_default_ignorable (&info[i])) ?
570 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH :
571 HB_OT_LAYOUT_GLYPH_PROPS_MARK;
572 _hb_glyph_info_set_glyph_props (&info[i], klass);
573 }
574 }
575
576 static inline void
577 hb_ot_substitute_default (hb_ot_shape_context_t *c)
578 {
579 hb_buffer_t *buffer = c->buffer;
580
581 if (c->plan->shaper->preprocess_text)
582 c->plan->shaper->preprocess_text (c->plan, buffer, c->font);
583
584 hb_ot_shape_initialize_masks (c);
585
586 hb_ot_mirror_chars (c);
587
588 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index);
589
590 _hb_ot_shape_normalize (c->plan, buffer, c->font);
591
592 hb_ot_shape_setup_masks (c);
593
594 /* This is unfortunate to go here, but necessary... */
595 if (!hb_ot_layout_has_positioning (c->face))
596 _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, buffer);
597
598 hb_ot_map_glyphs_fast (buffer);
599
600 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index);
601 }
602
603 static inline void
604 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
605 {
606 hb_buffer_t *buffer = c->buffer;
607
608 _hb_buffer_allocate_gsubgpos_vars (buffer);
609 hb_ot_layout_substitute_start (c->font, buffer);
610
611 if (!hb_ot_layout_has_glyph_classes (c->face))
612 hb_synthesize_glyph_classes (c);
613
614 c->plan->substitute (c->font, buffer);
615
616 hb_ot_layout_substitute_finish (c->font, buffer);
617
618 return;
619 }
620
621 static inline void
622 hb_ot_substitute (hb_ot_shape_context_t *c)
623 {
624 hb_ot_substitute_default (c);
625 hb_ot_substitute_complex (c);
626 }
627
628 /* Position */
629
630 static inline void
631 adjust_mark_offsets (hb_glyph_position_t *pos)
632 {
633 pos->x_offset -= pos->x_advance;
634 pos->y_offset -= pos->y_advance;
635 }
636
637 static inline void
638 zero_mark_width (hb_glyph_position_t *pos)
639 {
640 pos->x_advance = 0;
641 pos->y_advance = 0;
642 }
643
644 static inline void
645 zero_mark_widths_by_unicode (hb_buffer_t *buffer, bool adjust_offsets)
646 {
647 unsigned int count = buffer->len;
648 hb_glyph_info_t *info = buffer->info;
649 for (unsigned int i = 0; i < count; i++)
650 if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
651 {
652 if (adjust_offsets)
653 adjust_mark_offsets (&buffer->pos[i]);
654 zero_mark_width (&buffer->pos[i]);
655 }
656 }
657
658 static inline void
659 zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets)
660 {
661 unsigned int count = buffer->len;
662 hb_glyph_info_t *info = buffer->info;
663 for (unsigned int i = 0; i < count; i++)
664 if (_hb_glyph_info_is_mark (&info[i]))
665 {
666 if (adjust_offsets)
667 adjust_mark_offsets (&buffer->pos[i]);
668 zero_mark_width (&buffer->pos[i]);
669 }
670 }
671
672 static inline void
673 hb_ot_position_default (hb_ot_shape_context_t *c)
674 {
675 hb_direction_t direction = c->buffer->props.direction;
676 unsigned int count = c->buffer->len;
677 hb_glyph_info_t *info = c->buffer->info;
678 hb_glyph_position_t *pos = c->buffer->pos;
679 for (unsigned int i = 0; i < count; i++)
680 {
681 c->font->get_glyph_advance_for_direction (info[i].codepoint,
682 direction,
683 &pos[i].x_advance,
684 &pos[i].y_advance);
685 c->font->subtract_glyph_origin_for_direction (info[i].codepoint,
686 direction,
687 &pos[i].x_offset,
688 &pos[i].y_offset);
689
690 }
691 }
692
693 static inline bool
694 hb_ot_position_complex (hb_ot_shape_context_t *c)
695 {
696 bool ret = false;
697 unsigned int count = c->buffer->len;
698 bool has_positioning = hb_ot_layout_has_positioning (c->face);
699 /* If the font has no GPOS, AND, no fallback positioning will
700 * happen, AND, direction is forward, then when zeroing mark
701 * widths, we shift the mark with it, such that the mark
702 * is positioned hanging over the previous glyph. When
703 * direction is backward we don't shift and it will end up
704 * hanging over the next glyph after the final reordering.
705 * If fallback positinoing happens or GPOS is present, we don't
706 * care.
707 */
708 bool adjust_offsets_when_zeroing = !(has_positioning || c->plan->shaper->fallback_position ||
709 HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction));
710
711 switch (c->plan->shaper->zero_width_marks)
712 {
713 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
714 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
715 break;
716
717 /* Not currently used for any shaper:
718 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY:
719 zero_mark_widths_by_unicode (c->buffer, adjust_offsets_when_zeroing);
720 break;
721 */
722
723 default:
724 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
725 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE:
726 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
727 break;
728 }
729
730 if (has_positioning)
731 {
732 hb_glyph_info_t *info = c->buffer->info;
733 hb_glyph_position_t *pos = c->buffer->pos;
734
735 /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */
736
737 for (unsigned int i = 0; i < count; i++) {
738 c->font->add_glyph_origin_for_direction (info[i].codepoint,
739 HB_DIRECTION_LTR,
740 &pos[i].x_offset,
741 &pos[i].y_offset);
742 }
743
744 c->plan->position (c->font, c->buffer);
745
746 for (unsigned int i = 0; i < count; i++) {
747 c->font->subtract_glyph_origin_for_direction (info[i].codepoint,
748 HB_DIRECTION_LTR,
749 &pos[i].x_offset,
750 &pos[i].y_offset);
751 }
752
753 ret = true;
754 }
755
756 switch (c->plan->shaper->zero_width_marks)
757 {
758 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE:
759 zero_mark_widths_by_unicode (c->buffer, adjust_offsets_when_zeroing);
760 break;
761
762 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE:
763 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing);
764 break;
765
766 default:
767 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE:
768 //case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY:
769 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY:
770 break;
771 }
772
773 return ret;
774 }
775
776 static inline void
777 hb_ot_position (hb_ot_shape_context_t *c)
778 {
779 hb_ot_layout_position_start (c->font, c->buffer);
780
781 hb_ot_position_default (c);
782
783 hb_bool_t fallback = !hb_ot_position_complex (c);
784
785 hb_ot_zero_width_default_ignorables (c);
786
787 hb_ot_layout_position_finish (c->font, c->buffer);
788
789 if (fallback && c->plan->shaper->fallback_position)
790 _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer);
791
792 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
793 hb_buffer_reverse (c->buffer);
794
795 /* Visual fallback goes here. */
796
797 if (fallback)
798 _hb_ot_shape_fallback_kern (c->plan, c->font, c->buffer);
799
800 _hb_buffer_deallocate_gsubgpos_vars (c->buffer);
801 }
802
803
804 /* Pull it all together! */
805
806 static void
807 hb_ot_shape_internal (hb_ot_shape_context_t *c)
808 {
809 c->buffer->deallocate_var_all ();
810
811 /* Save the original direction, we use it later. */
812 c->target_direction = c->buffer->props.direction;
813
814 _hb_buffer_allocate_unicode_vars (c->buffer);
815
816 c->buffer->clear_output ();
817
818 hb_set_unicode_props (c->buffer);
819 hb_insert_dotted_circle (c->buffer, c->font);
820 hb_form_clusters (c->buffer);
821
822 hb_ensure_native_direction (c->buffer);
823
824 hb_ot_substitute (c);
825 hb_ot_position (c);
826
827 hb_ot_hide_default_ignorables (c);
828
829 _hb_buffer_deallocate_unicode_vars (c->buffer);
830
831 c->buffer->props.direction = c->target_direction;
832
833 c->buffer->deallocate_var_all ();
834 }
835
836
837 hb_bool_t
838 _hb_ot_shape (hb_shape_plan_t *shape_plan,
839 hb_font_t *font,
840 hb_buffer_t *buffer,
841 const hb_feature_t *features,
842 unsigned int num_features)
843 {
844 hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features};
845 hb_ot_shape_internal (&c);
846
847 return true;
848 }
849
850
851 /**
852 * Since: 0.9.7
853 **/
854 void
855 hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
856 hb_tag_t table_tag,
857 hb_set_t *lookup_indexes /* OUT */)
858 {
859 /* XXX Does the first part always succeed? */
860 HB_SHAPER_DATA_GET (shape_plan)->collect_lookups (table_tag, lookup_indexes);
861 }
862
863
864 /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
865 static void
866 add_char (hb_font_t *font,
867 hb_unicode_funcs_t *unicode,
868 hb_bool_t mirror,
869 hb_codepoint_t u,
870 hb_set_t *glyphs)
871 {
872 hb_codepoint_t glyph;
873 if (font->get_glyph (u, 0, &glyph))
874 glyphs->add (glyph);
875 if (mirror)
876 {
877 hb_codepoint_t m = unicode->mirroring (u);
878 if (m != u && font->get_glyph (m, 0, &glyph))
879 glyphs->add (glyph);
880 }
881 }
882
883
884 /**
885 * Since: 0.9.2
886 **/
887 void
888 hb_ot_shape_glyphs_closure (hb_font_t *font,
889 hb_buffer_t *buffer,
890 const hb_feature_t *features,
891 unsigned int num_features,
892 hb_set_t *glyphs)
893 {
894 hb_ot_shape_plan_t plan;
895
896 const char *shapers[] = {"ot", NULL};
897 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
898 features, num_features, shapers);
899
900 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
901
902 unsigned int count = buffer->len;
903 hb_glyph_info_t *info = buffer->info;
904 for (unsigned int i = 0; i < count; i++)
905 add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs);
906
907 hb_set_t lookups;
908 lookups.init ();
909 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, &lookups);
910
911 /* And find transitive closure. */
912 hb_set_t copy;
913 copy.init ();
914 do {
915 copy.set (glyphs);
916 for (hb_codepoint_t lookup_index = -1; hb_set_next (&lookups, &lookup_index);)
917 hb_ot_layout_lookup_substitute_closure (font->face, lookup_index, glyphs);
918 } while (!copy.is_equal (glyphs));
919
920 hb_shape_plan_destroy (shape_plan);
921 }