2 * Copyright (C) 2009,2010 Red Hat, Inc.
4 * This is part of HarfBuzz, a text shaping library.
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 * Red Hat Author(s): Behdad Esfahbod
27 #include "hb-ot-shape.h"
29 #include "hb-buffer-private.hh"
31 #include "hb-open-type-private.hh"
33 #include "hb-ot-layout.h"
39 hb_tag_t default_features[] = {
40 HB_TAG('c','a','l','t'),
41 HB_TAG('c','c','m','p'),
42 HB_TAG('c','l','i','g'),
43 HB_TAG('c','s','w','h'),
44 HB_TAG('c','u','r','s'),
45 HB_TAG('k','e','r','n'),
46 HB_TAG('l','i','g','a'),
47 HB_TAG('l','o','c','l'),
48 HB_TAG('m','a','r','k'),
49 HB_TAG('m','k','m','k'),
50 HB_TAG('r','l','i','g')
60 add_feature (hb_face_t *face,
62 unsigned int feature_index,
65 unsigned int *num_lookups,
66 unsigned int room_lookups)
68 unsigned int i = room_lookups - *num_lookups;
69 lookups += *num_lookups;
71 unsigned int *lookup_indices = (unsigned int *) lookups;
73 hb_ot_layout_feature_get_lookup_indexes (face, table_tag, feature_index, 0,
80 lookups[i].mask = mask;
81 lookups[i].index = lookup_indices[i];
86 cmp_lookups (const void *p1, const void *p2)
88 const lookup_map *a = (const lookup_map *) p1;
89 const lookup_map *b = (const lookup_map *) p2;
91 return a->index - b->index;
95 #define MAX_FEATURES 100
97 struct hb_mask_allocator_t {
99 struct feature_info_t {
106 cmp (const void *p1, const void *p2)
108 const feature_info_t *a = (const feature_info_t *) p1;
109 const feature_info_t *b = (const feature_info_t *) p2;
111 if (a->tag != b->tag)
112 return a->tag < b->tag ? -1 : 1;
114 return a->seq < b->seq ? -1 : 1;
118 struct feature_map_t {
119 hb_tag_t tag; /* should be first */
125 cmp (const void *p1, const void *p2)
127 const feature_map_t *a = (const feature_map_t *) p1;
128 const feature_map_t *b = (const feature_map_t *) p2;
130 return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0;
134 hb_mask_allocator_t (void) : count (0) {}
136 void add_feature (hb_tag_t tag,
140 feature_info_t *info = &infos[count++];
144 info->global = global;
147 void compile (hb_face_t *face,
149 unsigned int script_index,
150 unsigned int language_index)
153 unsigned int next_bit = 1;
158 qsort (infos, count, sizeof (infos[0]), feature_info_t::cmp);
161 for (unsigned int i = 1; i < count; i++)
162 if (infos[i].tag != infos[j].tag)
163 infos[++j] = infos[i];
168 infos[j].global = infos[j].global && (infos[j].value == infos[i].value);
169 infos[j].value = MAX (infos[j].value, infos[i].value);
174 /* Allocate bits now */
176 for (unsigned int i = 0; i < count; i++) {
177 const feature_info_t *info = &infos[i];
179 unsigned int bits_needed;
181 if (info->global && info->value == 1)
182 /* Uses the global bit */
185 bits_needed = _hb_bit_storage (info->value);
187 if (!info->value || next_bit + bits_needed > 8 * sizeof (hb_mask_t))
188 continue; /* Feature disabled, or not enough bits. */
190 unsigned int feature_index;
191 if (!hb_ot_layout_language_find_feature (face, table_tag, script_index, language_index,
192 info->tag, &feature_index))
195 feature_map_t *map = &maps[j++];
197 map->tag = info->tag;
198 map->index = feature_index;
199 if (info->global && info->value == 1) {
200 /* Use the global bit */
204 map->shift = next_bit;
205 map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);
206 next_bit += bits_needed;
209 if (info->global && map->mask != 1)
210 global_mask |= map->mask;
215 hb_mask_t get_global_mask (void) { return global_mask; }
216 const feature_map_t *find_feature (hb_tag_t tag) const {
217 static const feature_map_t off_map = { HB_TAG_NONE, Index::NOT_FOUND_INDEX, 0, 0 };
218 const feature_map_t *map = (const feature_map_t *) bsearch (&tag, maps, count, sizeof (maps[0]), feature_map_t::cmp);
219 return map ? map : &off_map;
226 feature_info_t infos[MAX_FEATURES];
228 feature_map_t maps[MAX_FEATURES];
229 hb_mask_t global_mask;
233 setup_lookups (hb_face_t *face,
235 hb_feature_t *features,
236 unsigned int num_features,
239 unsigned int *num_lookups,
240 hb_direction_t original_direction)
242 unsigned int i, j, script_index, language_index, feature_index, room_lookups;
244 room_lookups = *num_lookups;
247 hb_ot_layout_table_choose_script (face, table_tag,
248 hb_ot_tags_from_script (buffer->props.script),
250 hb_ot_layout_script_find_language (face, table_tag, script_index,
251 hb_ot_tag_from_language (buffer->props.language),
254 if (hb_ot_layout_language_get_required_feature_index (face, table_tag, script_index, language_index,
256 add_feature (face, table_tag, feature_index, 1, lookups, num_lookups, room_lookups);
259 hb_mask_allocator_t allocator;
261 switch (original_direction) {
262 case HB_DIRECTION_LTR:
263 allocator.add_feature (HB_TAG ('l','t','r','a'), 1, true);
264 allocator.add_feature (HB_TAG ('l','t','r','m'), 1, true);
266 case HB_DIRECTION_RTL:
267 allocator.add_feature (HB_TAG ('r','t','l','a'), 1, true);
268 allocator.add_feature (HB_TAG ('r','t','l','m'), 1, false);
270 case HB_DIRECTION_TTB:
271 case HB_DIRECTION_BTT:
276 for (i = 0; i < ARRAY_LENGTH (default_features); i++)
277 allocator.add_feature (default_features[i], 1, true);
279 /* XXX complex-shaper features go here */
281 for (unsigned int i = 0; i < num_features; i++) {
282 const hb_feature_t *feature = &features[i];
283 allocator.add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
287 /* Compile features */
288 allocator.compile (face, table_tag, script_index, language_index);
291 /* Gather lookup indices for features and set buffer masks at the same time */
293 const hb_mask_allocator_t::feature_map_t *map;
295 hb_mask_t global_mask = allocator.get_global_mask ();
297 buffer->set_masks (global_mask, global_mask, 0, (unsigned int) -1);
299 switch (original_direction) {
300 case HB_DIRECTION_LTR:
301 map = allocator.find_feature (HB_TAG ('l','t','r','a'));
302 add_feature (face, table_tag, map->index, map->mask, lookups, num_lookups, room_lookups);
303 map = allocator.find_feature (HB_TAG ('l','t','r','m'));
304 add_feature (face, table_tag, map->index, map->mask, lookups, num_lookups, room_lookups);
306 case HB_DIRECTION_RTL:
307 map = allocator.find_feature (HB_TAG ('r','t','l','a'));
308 add_feature (face, table_tag, map->index, map->mask, lookups, num_lookups, room_lookups);
309 map = allocator.find_feature (HB_TAG ('r','t','l','m'));
310 add_feature (face, table_tag, map->index, map->mask, lookups, num_lookups, room_lookups);
312 case HB_DIRECTION_TTB:
313 case HB_DIRECTION_BTT:
318 for (i = 0; i < ARRAY_LENGTH (default_features); i++)
320 map = allocator.find_feature (default_features[i]);
321 add_feature (face, table_tag, map->index, map->mask, lookups, num_lookups, room_lookups);
324 for (i = 0; i < num_features; i++)
326 hb_feature_t *feature = &features[i];
327 map = allocator.find_feature (feature->tag);
328 add_feature (face, table_tag, map->index, map->mask, lookups, num_lookups, room_lookups);
329 if (!(feature->start == 0 && feature->end == (unsigned int)-1))
330 buffer->set_masks (features[i].value << map->shift, map->mask, feature->start, feature->end);
334 /* Sort lookups and merge duplicates */
336 qsort (lookups, *num_lookups, sizeof (lookups[0]), cmp_lookups);
340 for (i = 1, j = 0; i < *num_lookups; i++)
341 if (lookups[i].index != lookups[j].index)
342 lookups[++j] = lookups[i];
344 lookups[j].mask |= lookups[i].mask;
352 hb_ot_substitute_complex (hb_font_t *font HB_UNUSED,
355 hb_feature_t *features,
356 unsigned int num_features,
357 hb_direction_t original_direction)
359 lookup_map lookups[1000]; /* FIXME */
360 unsigned int num_lookups = ARRAY_LENGTH (lookups);
363 if (!hb_ot_layout_has_substitution (face))
366 setup_lookups (face, buffer, features, num_features,
368 lookups, &num_lookups,
371 for (i = 0; i < num_lookups; i++)
372 hb_ot_layout_substitute_lookup (face, buffer, lookups[i].index, lookups[i].mask);
378 hb_ot_position_complex (hb_font_t *font,
381 hb_feature_t *features,
382 unsigned int num_features,
383 hb_direction_t original_direction)
385 lookup_map lookups[1000];
386 unsigned int num_lookups = ARRAY_LENGTH (lookups);
389 if (!hb_ot_layout_has_positioning (face))
392 setup_lookups (face, buffer, features, num_features,
394 lookups, &num_lookups,
397 for (i = 0; i < num_lookups; i++)
398 hb_ot_layout_position_lookup (font, face, buffer, lookups[i].index, lookups[i].mask);
400 hb_ot_layout_position_finish (font, face, buffer);
410 static inline hb_bool_t
411 is_variation_selector (hb_codepoint_t unicode)
413 return unlikely ((unicode >= 0x180B && unicode <= 0x180D) || /* MONGOLIAN FREE VARIATION SELECTOR ONE..THREE */
414 (unicode >= 0xFE00 && unicode <= 0xFE0F) || /* VARIATION SELECTOR-1..16 */
415 (unicode >= 0xE0100 && unicode <= 0xE01EF)); /* VARIATION SELECTOR-17..256 */
419 hb_form_clusters (hb_buffer_t *buffer)
421 unsigned int count = buffer->len;
422 for (unsigned int i = 1; i < count; i++)
423 if (buffer->unicode->v.get_general_category (buffer->info[i].codepoint) == HB_CATEGORY_NON_SPACING_MARK)
424 buffer->info[i].cluster = buffer->info[i - 1].cluster;
427 static hb_direction_t
428 hb_ensure_native_direction (hb_buffer_t *buffer)
430 hb_direction_t original_direction = buffer->props.direction;
433 if (HB_DIRECTION_IS_HORIZONTAL (original_direction) &&
434 original_direction != _hb_script_get_horizontal_direction (buffer->props.script))
436 hb_buffer_reverse_clusters (buffer);
437 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
440 return original_direction;
447 hb_mirror_chars (hb_buffer_t *buffer)
449 hb_unicode_get_mirroring_func_t get_mirroring = buffer->unicode->v.get_mirroring;
451 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
454 // map = allocator.find_feature (HB_TAG ('r','t','l','m'));
456 unsigned int count = buffer->len;
457 for (unsigned int i = 0; i < count; i++) {
458 hb_codepoint_t codepoint = get_mirroring (buffer->info[i].codepoint);
459 if (likely (codepoint == buffer->info[i].codepoint))
460 ;// buffer->info[i].mask |= map->mask;
462 buffer->info[i].codepoint = codepoint;
467 hb_map_glyphs (hb_font_t *font,
471 if (unlikely (!buffer->len))
474 buffer->clear_output ();
475 unsigned int count = buffer->len - 1;
476 for (buffer->i = 0; buffer->i < count;) {
477 if (unlikely (is_variation_selector (buffer->info[buffer->i + 1].codepoint))) {
478 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, buffer->info[buffer->i + 1].codepoint));
481 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
484 if (likely (buffer->i < buffer->len))
485 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
490 hb_substitute_default (hb_font_t *font,
493 hb_feature_t *features HB_UNUSED,
494 unsigned int num_features HB_UNUSED)
496 hb_map_glyphs (font, face, buffer);
500 hb_substitute_complex_fallback (hb_font_t *font HB_UNUSED,
501 hb_face_t *face HB_UNUSED,
502 hb_buffer_t *buffer HB_UNUSED,
503 hb_feature_t *features HB_UNUSED,
504 unsigned int num_features HB_UNUSED)
513 hb_position_default (hb_font_t *font,
516 hb_feature_t *features HB_UNUSED,
517 unsigned int num_features HB_UNUSED)
519 hb_buffer_clear_positions (buffer);
521 unsigned int count = buffer->len;
522 for (unsigned int i = 0; i < count; i++) {
523 hb_glyph_metrics_t metrics;
524 hb_font_get_glyph_metrics (font, face, buffer->info[i].codepoint, &metrics);
525 buffer->pos[i].x_advance = metrics.x_advance;
526 buffer->pos[i].y_advance = metrics.y_advance;
531 hb_position_complex_fallback (hb_font_t *font HB_UNUSED,
532 hb_face_t *face HB_UNUSED,
533 hb_buffer_t *buffer HB_UNUSED,
534 hb_feature_t *features HB_UNUSED,
535 unsigned int num_features HB_UNUSED)
541 hb_truetype_kern (hb_font_t *font,
544 hb_feature_t *features HB_UNUSED,
545 unsigned int num_features HB_UNUSED)
547 /* TODO Check for kern=0 */
548 unsigned int count = buffer->len;
549 for (unsigned int i = 1; i < count; i++) {
550 hb_position_t kern, kern1, kern2;
551 kern = hb_font_get_kerning (font, face, buffer->info[i - 1].codepoint, buffer->info[i].codepoint);
553 kern2 = kern - kern1;
554 buffer->pos[i - 1].x_advance += kern1;
555 buffer->pos[i].x_advance += kern2;
556 buffer->pos[i].x_offset += kern2;
561 hb_position_complex_fallback_visual (hb_font_t *font,
564 hb_feature_t *features,
565 unsigned int num_features)
567 hb_truetype_kern (font, face, buffer, features, num_features);
574 hb_ot_shape (hb_font_t *font,
577 hb_feature_t *features,
578 unsigned int num_features)
580 hb_direction_t original_direction;
581 hb_bool_t substitute_fallback, position_fallback;
583 hb_form_clusters (buffer);
587 buffer->clear_masks ();
589 /* Mirroring needs to see the original direction */
590 hb_mirror_chars (buffer);
592 original_direction = hb_ensure_native_direction (buffer);
594 hb_substitute_default (font, face, buffer, features, num_features);
596 substitute_fallback = !hb_ot_substitute_complex (font, face, buffer, features, num_features, original_direction);
598 if (substitute_fallback)
599 hb_substitute_complex_fallback (font, face, buffer, features, num_features);
604 buffer->clear_masks ();
606 hb_position_default (font, face, buffer, features, num_features);
608 position_fallback = !hb_ot_position_complex (font, face, buffer, features, num_features, original_direction);
610 if (position_fallback)
611 hb_position_complex_fallback (font, face, buffer, features, num_features);
613 if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
614 hb_buffer_reverse (buffer);
616 if (position_fallback)
617 hb_position_complex_fallback_visual (font, face, buffer, features, num_features);
620 buffer->props.direction = original_direction;