2 * Copyright © 2009,2010 Red Hat, Inc.
3 * Copyright © 2010,2011,2012 Google, Inc.
5 * This is part of HarfBuzz, a text shaping library.
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.
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
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.
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
30 #define hb_ot_shaper_face_data_t hb_ot_layout_t
31 #define hb_ot_shaper_shape_plan_data_t hb_ot_shape_plan_t
32 #include "hb-shaper-impl-private.hh"
34 #include "hb-ot-shape-private.hh"
35 #include "hb-ot-shape-complex-private.hh"
36 #include "hb-ot-shape-fallback-private.hh"
37 #include "hb-ot-shape-normalize-private.hh"
39 #include "hb-ot-layout-private.hh"
40 #include "hb-set-private.hh"
43 static hb_tag_t common_features[] = {
44 HB_TAG('c','c','m','p'),
45 HB_TAG('l','i','g','a'),
46 HB_TAG('l','o','c','l'),
47 HB_TAG('m','a','r','k'),
48 HB_TAG('m','k','m','k'),
49 HB_TAG('r','l','i','g'),
53 static hb_tag_t horizontal_features[] = {
54 HB_TAG('c','a','l','t'),
55 HB_TAG('c','l','i','g'),
56 HB_TAG('c','u','r','s'),
57 HB_TAG('k','e','r','n'),
58 HB_TAG('r','c','l','t'),
62 * Technically speaking, vrt2 and vert are mutually exclusive.
63 * According to the spec, valt and vpal are also mutually exclusive.
64 * But we apply them all for now.
66 static hb_tag_t vertical_features[] = {
67 HB_TAG('v','a','l','t'),
68 HB_TAG('v','e','r','t'),
69 HB_TAG('v','k','r','n'),
70 HB_TAG('v','p','a','l'),
71 HB_TAG('v','r','t','2'),
77 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
78 const hb_segment_properties_t *props,
79 const hb_feature_t *user_features,
80 unsigned int num_user_features)
82 hb_ot_map_builder_t *map = &planner->map;
84 switch (props->direction) {
85 case HB_DIRECTION_LTR:
86 map->add_bool_feature (HB_TAG ('l','t','r','a'));
87 map->add_bool_feature (HB_TAG ('l','t','r','m'));
89 case HB_DIRECTION_RTL:
90 map->add_bool_feature (HB_TAG ('r','t','l','a'));
91 map->add_bool_feature (HB_TAG ('r','t','l','m'), false);
93 case HB_DIRECTION_TTB:
94 case HB_DIRECTION_BTT:
95 case HB_DIRECTION_INVALID:
100 #define ADD_FEATURES(array) \
102 for (unsigned int i = 0; i < ARRAY_LENGTH (array); i++) \
103 map->add_bool_feature (array[i]); \
106 if (planner->shaper->collect_features)
107 planner->shaper->collect_features (planner);
109 ADD_FEATURES (common_features);
111 if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
112 ADD_FEATURES (horizontal_features);
114 ADD_FEATURES (vertical_features);
116 if (planner->shaper->override_features)
117 planner->shaper->override_features (planner);
121 for (unsigned int i = 0; i < num_user_features; i++) {
122 const hb_feature_t *feature = &user_features[i];
123 map->add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
132 hb_ot_shaper_face_data_t *
133 _hb_ot_shaper_face_data_create (hb_face_t *face)
135 return _hb_ot_layout_create (face);
139 _hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data)
141 _hb_ot_layout_destroy (data);
149 struct hb_ot_shaper_font_data_t {};
151 hb_ot_shaper_font_data_t *
152 _hb_ot_shaper_font_data_create (hb_font_t *font)
154 return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
158 _hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data)
164 * shaper shape_plan data
167 hb_ot_shaper_shape_plan_data_t *
168 _hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan,
169 const hb_feature_t *user_features,
170 unsigned int num_user_features)
172 hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t));
173 if (unlikely (!plan))
176 hb_ot_shape_planner_t planner (shape_plan);
178 planner.shaper = hb_ot_shape_complex_categorize (&planner);
180 hb_ot_shape_collect_features (&planner, &shape_plan->props, user_features, num_user_features);
182 planner.compile (*plan);
184 if (plan->shaper->data_create) {
185 plan->data = plan->shaper->data_create (plan);
186 if (unlikely (!plan->data))
194 _hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan)
196 if (plan->shaper->data_destroy)
197 plan->shaper->data_destroy (const_cast<void *> (plan->data));
209 struct hb_ot_shape_context_t
211 hb_ot_shape_plan_t *plan;
215 const hb_feature_t *user_features;
216 unsigned int num_user_features;
218 /* Transient stuff */
219 hb_direction_t target_direction;
230 hb_set_unicode_props (hb_buffer_t *buffer)
232 unsigned int count = buffer->len;
233 for (unsigned int i = 0; i < count; i++)
234 _hb_glyph_info_set_unicode_props (&buffer->info[i], buffer->unicode);
238 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
240 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) ||
241 _hb_glyph_info_get_general_category (&buffer->info[0]) !=
242 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
245 hb_codepoint_t dottedcircle_glyph;
246 if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph))
249 hb_glyph_info_t dottedcircle;
250 dottedcircle.codepoint = 0x25CC;
251 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer->unicode);
253 buffer->clear_output ();
256 hb_glyph_info_t info = dottedcircle;
257 info.cluster = buffer->cur().cluster;
258 info.mask = buffer->cur().mask;
259 buffer->output_info (info);
260 while (buffer->idx < buffer->len)
261 buffer->next_glyph ();
263 buffer->swap_buffers ();
267 hb_form_clusters (hb_buffer_t *buffer)
269 unsigned int count = buffer->len;
270 for (unsigned int i = 1; i < count; i++)
271 if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i])))
272 buffer->merge_clusters (i - 1, i + 1);
276 hb_ensure_native_direction (hb_buffer_t *buffer)
278 hb_direction_t direction = buffer->props.direction;
281 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
282 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
284 if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) ||
285 (HB_DIRECTION_IS_VERTICAL (direction) && direction != HB_DIRECTION_TTB))
287 hb_buffer_reverse_clusters (buffer);
288 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
296 hb_ot_mirror_chars (hb_ot_shape_context_t *c)
298 if (HB_DIRECTION_IS_FORWARD (c->target_direction))
301 hb_unicode_funcs_t *unicode = c->buffer->unicode;
302 hb_mask_t rtlm_mask = c->plan->map.get_1_mask (HB_TAG ('r','t','l','m'));
304 unsigned int count = c->buffer->len;
305 for (unsigned int i = 0; i < count; i++) {
306 hb_codepoint_t codepoint = unicode->mirroring (c->buffer->info[i].codepoint);
307 if (likely (codepoint == c->buffer->info[i].codepoint))
308 c->buffer->info[i].mask |= rtlm_mask;
310 c->buffer->info[i].codepoint = codepoint;
315 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
317 hb_ot_map_t *map = &c->plan->map;
319 hb_mask_t global_mask = map->get_global_mask ();
320 c->buffer->reset_masks (global_mask);
322 if (c->plan->shaper->setup_masks)
323 c->plan->shaper->setup_masks (c->plan, c->buffer, c->font);
325 for (unsigned int i = 0; i < c->num_user_features; i++)
327 const hb_feature_t *feature = &c->user_features[i];
328 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
330 hb_mask_t mask = map->get_mask (feature->tag, &shift);
331 c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
337 hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
339 /* Normalization process sets up glyph_index(), we just copy it. */
340 unsigned int count = buffer->len;
341 for (unsigned int i = 0; i < count; i++)
342 buffer->info[i].codepoint = buffer->info[i].glyph_index();
346 hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
348 unsigned int count = c->buffer->len;
349 for (unsigned int i = 0; i < count; i++)
350 c->buffer->info[i].glyph_props() = _hb_glyph_info_get_general_category (&c->buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ?
351 HB_OT_LAYOUT_GLYPH_PROPS_MARK :
352 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH;
356 hb_ot_substitute_default (hb_ot_shape_context_t *c)
358 if (c->plan->shaper->preprocess_text)
359 c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
361 hb_ot_mirror_chars (c);
363 HB_BUFFER_ALLOCATE_VAR (c->buffer, glyph_index);
365 _hb_ot_shape_normalize (c->plan, c->buffer, c->font);
367 hb_ot_shape_setup_masks (c);
369 /* This is unfortunate to go here, but necessary... */
370 if (!hb_ot_layout_has_positioning (c->face))
371 _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, c->buffer);
373 hb_ot_map_glyphs_fast (c->buffer);
375 HB_BUFFER_DEALLOCATE_VAR (c->buffer, glyph_index);
379 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
381 hb_ot_layout_substitute_start (c->font, c->buffer);
383 if (!hb_ot_layout_has_glyph_classes (c->face))
384 hb_synthesize_glyph_classes (c);
386 c->plan->substitute (c->font, c->buffer);
388 hb_ot_layout_substitute_finish (c->font, c->buffer);
394 hb_ot_substitute (hb_ot_shape_context_t *c)
396 hb_ot_substitute_default (c);
397 hb_ot_substitute_complex (c);
403 hb_ot_position_default (hb_ot_shape_context_t *c)
405 hb_ot_layout_position_start (c->font, c->buffer);
407 unsigned int count = c->buffer->len;
408 for (unsigned int i = 0; i < count; i++) {
409 c->font->get_glyph_advance_for_direction (c->buffer->info[i].codepoint,
410 c->buffer->props.direction,
411 &c->buffer->pos[i].x_advance,
412 &c->buffer->pos[i].y_advance);
413 c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint,
414 c->buffer->props.direction,
415 &c->buffer->pos[i].x_offset,
416 &c->buffer->pos[i].y_offset);
421 hb_ot_position_complex (hb_ot_shape_context_t *c)
425 if (hb_ot_layout_has_positioning (c->face))
427 /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */
429 unsigned int count = c->buffer->len;
430 for (unsigned int i = 0; i < count; i++) {
431 c->font->add_glyph_origin_for_direction (c->buffer->info[i].codepoint,
433 &c->buffer->pos[i].x_offset,
434 &c->buffer->pos[i].y_offset);
437 c->plan->position (c->font, c->buffer);
439 for (unsigned int i = 0; i < count; i++) {
440 c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint,
442 &c->buffer->pos[i].x_offset,
443 &c->buffer->pos[i].y_offset);
449 hb_ot_layout_position_finish (c->font, c->buffer, c->plan->shaper->zero_width_attached_marks);
455 hb_ot_truetype_kern (hb_ot_shape_context_t *c)
457 /* TODO Check for kern=0 */
458 unsigned int count = c->buffer->len;
459 for (unsigned int i = 1; i < count; i++) {
460 hb_position_t x_kern, y_kern, kern1, kern2;
461 c->font->get_glyph_kerning_for_direction (c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint,
462 c->buffer->props.direction,
466 kern2 = x_kern - kern1;
467 c->buffer->pos[i - 1].x_advance += kern1;
468 c->buffer->pos[i].x_advance += kern2;
469 c->buffer->pos[i].x_offset += kern2;
472 kern2 = y_kern - kern1;
473 c->buffer->pos[i - 1].y_advance += kern1;
474 c->buffer->pos[i].y_advance += kern2;
475 c->buffer->pos[i].y_offset += kern2;
480 hb_ot_position (hb_ot_shape_context_t *c)
482 hb_ot_position_default (c);
484 hb_bool_t fallback = !hb_ot_position_complex (c);
486 if (fallback && c->plan->shaper->fallback_position)
487 _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer);
489 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
490 hb_buffer_reverse (c->buffer);
492 /* Visual fallback goes here. */
495 hb_ot_truetype_kern (c);
502 hb_ot_hide_default_ignorables (hb_ot_shape_context_t *c)
504 if (c->buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES)
507 hb_codepoint_t space = 0;
509 unsigned int count = c->buffer->len;
510 for (unsigned int i = 0; i < count; i++)
511 if (unlikely (!is_a_ligature (c->buffer->info[i]) &&
512 _hb_glyph_info_is_default_ignorable (&c->buffer->info[i])))
515 /* We assume that the space glyph is not gid0. */
516 if (unlikely (!c->font->get_glyph (' ', 0, &space)) || !space)
517 return; /* No point! */
519 c->buffer->info[i].codepoint = space;
520 c->buffer->pos[i].x_advance = 0;
521 c->buffer->pos[i].y_advance = 0;
526 /* Pull it all together! */
529 hb_ot_shape_internal (hb_ot_shape_context_t *c)
531 c->buffer->deallocate_var_all ();
533 /* Save the original direction, we use it later. */
534 c->target_direction = c->buffer->props.direction;
536 HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props0);
537 HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props1);
539 c->buffer->clear_output ();
541 hb_set_unicode_props (c->buffer);
542 hb_insert_dotted_circle (c->buffer, c->font);
543 hb_form_clusters (c->buffer);
545 hb_ensure_native_direction (c->buffer);
547 hb_ot_substitute (c);
550 hb_ot_hide_default_ignorables (c);
552 HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props1);
553 HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props0);
555 c->buffer->props.direction = c->target_direction;
557 c->buffer->deallocate_var_all ();
562 _hb_ot_shape (hb_shape_plan_t *shape_plan,
565 const hb_feature_t *features,
566 unsigned int num_features)
568 hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features};
569 hb_ot_shape_internal (&c);
576 hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan,
578 hb_set_t *lookup_indexes /* OUT */)
580 /* XXX Does the first part always succeed? */
581 HB_SHAPER_DATA_GET (shape_plan)->collect_lookups (table_tag, lookup_indexes);
585 /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */
587 add_char (hb_font_t *font,
588 hb_unicode_funcs_t *unicode,
593 hb_codepoint_t glyph;
594 if (font->get_glyph (u, 0, &glyph))
598 hb_codepoint_t m = unicode->mirroring (u);
599 if (m != u && font->get_glyph (m, 0, &glyph))
606 hb_ot_shape_glyphs_closure (hb_font_t *font,
608 const hb_feature_t *features,
609 unsigned int num_features,
612 hb_ot_shape_plan_t plan;
614 buffer->guess_segment_properties ();
616 const char *shapers[] = {"ot", NULL};
617 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props,
618 features, num_features, shapers);
620 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL;
622 unsigned int count = buffer->len;
623 for (unsigned int i = 0; i < count; i++)
624 add_char (font, buffer->unicode, mirror, buffer->info[i].codepoint, glyphs);
628 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, &lookups);
630 /* And find transitive closure. */
635 for (hb_codepoint_t lookup_index = -1; hb_set_next (&lookups, &lookup_index);)
636 hb_ot_layout_lookup_substitute_closure (font->face, lookup_index, glyphs);
637 } while (!copy.is_equal (glyphs));
639 hb_shape_plan_destroy (shape_plan);