hb-ot-shape.cc revision 91689de2603e4151e2a2d3a3852c61667f0c6264
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#define HB_SHAPER ot 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" 33 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" 38 39#include "hb-ot-layout-private.hh" 40#include "hb-set-private.hh" 41 42 43static 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'), 50}; 51 52 53static 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'), 59}; 60 61static hb_tag_t vertical_features[] = { 62 HB_TAG('v','e','r','t'), 63}; 64 65 66 67static void 68hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner, 69 const hb_segment_properties_t *props, 70 const hb_feature_t *user_features, 71 unsigned int num_user_features) 72{ 73 hb_ot_map_builder_t *map = &planner->map; 74 75 switch (props->direction) { 76 case HB_DIRECTION_LTR: 77 map->add_global_bool_feature (HB_TAG ('l','t','r','a')); 78 map->add_global_bool_feature (HB_TAG ('l','t','r','m')); 79 break; 80 case HB_DIRECTION_RTL: 81 map->add_global_bool_feature (HB_TAG ('r','t','l','a')); 82 map->add_feature (HB_TAG ('r','t','l','m'), 1, F_NONE); 83 break; 84 case HB_DIRECTION_TTB: 85 case HB_DIRECTION_BTT: 86 case HB_DIRECTION_INVALID: 87 default: 88 break; 89 } 90 91 if (planner->shaper->collect_features) 92 planner->shaper->collect_features (planner); 93 94 for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++) 95 map->add_global_bool_feature (common_features[i]); 96 97 if (HB_DIRECTION_IS_HORIZONTAL (props->direction)) 98 for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++) 99 map->add_feature (horizontal_features[i], 1, F_GLOBAL | 100 (horizontal_features[i] == HB_TAG('k','e','r','n') ? 101 F_HAS_FALLBACK : F_NONE)); 102 else 103 for (unsigned int i = 0; i < ARRAY_LENGTH (vertical_features); i++) 104 map->add_feature (vertical_features[i], 1, F_GLOBAL | 105 (vertical_features[i] == HB_TAG('v','k','r','n') ? 106 F_HAS_FALLBACK : F_NONE)); 107 108 if (planner->shaper->override_features) 109 planner->shaper->override_features (planner); 110 111 for (unsigned int i = 0; i < num_user_features; i++) { 112 const hb_feature_t *feature = &user_features[i]; 113 map->add_feature (feature->tag, feature->value, 114 (feature->start == 0 && feature->end == (unsigned int) -1) ? 115 F_GLOBAL : F_NONE); 116 } 117} 118 119 120/* 121 * shaper face data 122 */ 123 124hb_ot_shaper_face_data_t * 125_hb_ot_shaper_face_data_create (hb_face_t *face) 126{ 127 return _hb_ot_layout_create (face); 128} 129 130void 131_hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data) 132{ 133 _hb_ot_layout_destroy (data); 134} 135 136 137/* 138 * shaper font data 139 */ 140 141struct hb_ot_shaper_font_data_t {}; 142 143hb_ot_shaper_font_data_t * 144_hb_ot_shaper_font_data_create (hb_font_t *font) 145{ 146 return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED; 147} 148 149void 150_hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data) 151{ 152} 153 154 155/* 156 * shaper shape_plan data 157 */ 158 159hb_ot_shaper_shape_plan_data_t * 160_hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan, 161 const hb_feature_t *user_features, 162 unsigned int num_user_features) 163{ 164 hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t)); 165 if (unlikely (!plan)) 166 return NULL; 167 168 hb_ot_shape_planner_t planner (shape_plan); 169 170 planner.shaper = hb_ot_shape_complex_categorize (&planner); 171 172 hb_ot_shape_collect_features (&planner, &shape_plan->props, user_features, num_user_features); 173 174 planner.compile (*plan); 175 176 if (plan->shaper->data_create) { 177 plan->data = plan->shaper->data_create (plan); 178 if (unlikely (!plan->data)) 179 return NULL; 180 } 181 182 return plan; 183} 184 185void 186_hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan) 187{ 188 if (plan->shaper->data_destroy) 189 plan->shaper->data_destroy (const_cast<void *> (plan->data)); 190 191 plan->finish (); 192 193 free (plan); 194} 195 196 197/* 198 * shaper 199 */ 200 201struct hb_ot_shape_context_t 202{ 203 hb_ot_shape_plan_t *plan; 204 hb_font_t *font; 205 hb_face_t *face; 206 hb_buffer_t *buffer; 207 const hb_feature_t *user_features; 208 unsigned int num_user_features; 209 210 /* Transient stuff */ 211 hb_direction_t target_direction; 212}; 213 214 215 216/* Main shaper */ 217 218 219/* Prepare */ 220 221static void 222hb_set_unicode_props (hb_buffer_t *buffer) 223{ 224 unsigned int count = buffer->len; 225 for (unsigned int i = 0; i < count; i++) 226 _hb_glyph_info_set_unicode_props (&buffer->info[i], buffer->unicode); 227} 228 229static void 230hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font) 231{ 232 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) || 233 _hb_glyph_info_get_general_category (&buffer->info[0]) != 234 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) 235 return; 236 237 hb_codepoint_t dottedcircle_glyph; 238 if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph)) 239 return; 240 241 hb_glyph_info_t dottedcircle; 242 dottedcircle.codepoint = 0x25CC; 243 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer->unicode); 244 245 buffer->clear_output (); 246 247 buffer->idx = 0; 248 hb_glyph_info_t info = dottedcircle; 249 info.cluster = buffer->cur().cluster; 250 info.mask = buffer->cur().mask; 251 buffer->output_info (info); 252 while (buffer->idx < buffer->len) 253 buffer->next_glyph (); 254 255 buffer->swap_buffers (); 256} 257 258static void 259hb_form_clusters (hb_buffer_t *buffer) 260{ 261 unsigned int count = buffer->len; 262 for (unsigned int i = 1; i < count; i++) 263 if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i]))) 264 buffer->merge_clusters (i - 1, i + 1); 265} 266 267static void 268hb_ensure_native_direction (hb_buffer_t *buffer) 269{ 270 hb_direction_t direction = buffer->props.direction; 271 272 /* TODO vertical: 273 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType 274 * Ogham fonts are supposed to be implemented BTT or not. Need to research that 275 * first. */ 276 if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) || 277 (HB_DIRECTION_IS_VERTICAL (direction) && direction != HB_DIRECTION_TTB)) 278 { 279 hb_buffer_reverse_clusters (buffer); 280 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction); 281 } 282} 283 284 285/* Substitute */ 286 287static inline void 288hb_ot_mirror_chars (hb_ot_shape_context_t *c) 289{ 290 if (HB_DIRECTION_IS_FORWARD (c->target_direction)) 291 return; 292 293 hb_unicode_funcs_t *unicode = c->buffer->unicode; 294 hb_mask_t rtlm_mask = c->plan->map.get_1_mask (HB_TAG ('r','t','l','m')); 295 296 unsigned int count = c->buffer->len; 297 for (unsigned int i = 0; i < count; i++) { 298 hb_codepoint_t codepoint = unicode->mirroring (c->buffer->info[i].codepoint); 299 if (likely (codepoint == c->buffer->info[i].codepoint)) 300 c->buffer->info[i].mask |= rtlm_mask; 301 else 302 c->buffer->info[i].codepoint = codepoint; 303 } 304} 305 306static inline void 307hb_ot_shape_setup_masks (hb_ot_shape_context_t *c) 308{ 309 hb_ot_map_t *map = &c->plan->map; 310 311 hb_mask_t global_mask = map->get_global_mask (); 312 c->buffer->reset_masks (global_mask); 313 314 if (c->plan->shaper->setup_masks) 315 c->plan->shaper->setup_masks (c->plan, c->buffer, c->font); 316 317 for (unsigned int i = 0; i < c->num_user_features; i++) 318 { 319 const hb_feature_t *feature = &c->user_features[i]; 320 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) { 321 unsigned int shift; 322 hb_mask_t mask = map->get_mask (feature->tag, &shift); 323 c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end); 324 } 325 } 326} 327 328static inline void 329hb_ot_map_glyphs_fast (hb_buffer_t *buffer) 330{ 331 /* Normalization process sets up glyph_index(), we just copy it. */ 332 unsigned int count = buffer->len; 333 for (unsigned int i = 0; i < count; i++) 334 buffer->info[i].codepoint = buffer->info[i].glyph_index(); 335} 336 337static inline void 338hb_synthesize_glyph_classes (hb_ot_shape_context_t *c) 339{ 340 unsigned int count = c->buffer->len; 341 for (unsigned int i = 0; i < count; i++) 342 _hb_glyph_info_set_glyph_props (&c->buffer->info[i], 343 _hb_glyph_info_get_general_category (&c->buffer->info[i]) 344 == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ? 345 HB_OT_LAYOUT_GLYPH_PROPS_MARK : 346 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH); 347} 348 349static inline void 350hb_ot_substitute_default (hb_ot_shape_context_t *c) 351{ 352 if (c->plan->shaper->preprocess_text) 353 c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font); 354 355 hb_ot_mirror_chars (c); 356 357 HB_BUFFER_ALLOCATE_VAR (c->buffer, glyph_index); 358 359 _hb_ot_shape_normalize (c->plan, c->buffer, c->font); 360 361 hb_ot_shape_setup_masks (c); 362 363 /* This is unfortunate to go here, but necessary... */ 364 if (!hb_ot_layout_has_positioning (c->face)) 365 _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, c->buffer); 366 367 hb_ot_map_glyphs_fast (c->buffer); 368 369 HB_BUFFER_DEALLOCATE_VAR (c->buffer, glyph_index); 370} 371 372static inline void 373hb_ot_substitute_complex (hb_ot_shape_context_t *c) 374{ 375 hb_ot_layout_substitute_start (c->font, c->buffer); 376 377 if (!hb_ot_layout_has_glyph_classes (c->face)) 378 hb_synthesize_glyph_classes (c); 379 380 c->plan->substitute (c->font, c->buffer); 381 382 hb_ot_layout_substitute_finish (c->font, c->buffer); 383 384 return; 385} 386 387static inline void 388hb_ot_substitute (hb_ot_shape_context_t *c) 389{ 390 hb_ot_substitute_default (c); 391 hb_ot_substitute_complex (c); 392} 393 394/* Position */ 395 396static inline void 397zero_mark_widths_by_unicode (hb_buffer_t *buffer) 398{ 399 unsigned int count = buffer->len; 400 for (unsigned int i = 0; i < count; i++) 401 if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) 402 { 403 buffer->pos[i].x_advance = 0; 404 buffer->pos[i].y_advance = 0; 405 } 406} 407 408static inline void 409zero_mark_widths_by_gdef (hb_buffer_t *buffer) 410{ 411 unsigned int count = buffer->len; 412 for (unsigned int i = 0; i < count; i++) 413 if ((buffer->info[i].glyph_props() & HB_OT_LAYOUT_GLYPH_PROPS_MARK)) 414 { 415 buffer->pos[i].x_advance = 0; 416 buffer->pos[i].y_advance = 0; 417 } 418} 419 420static inline void 421hb_ot_position_default (hb_ot_shape_context_t *c) 422{ 423 unsigned int count = c->buffer->len; 424 for (unsigned int i = 0; i < count; i++) 425 { 426 c->font->get_glyph_advance_for_direction (c->buffer->info[i].codepoint, 427 c->buffer->props.direction, 428 &c->buffer->pos[i].x_advance, 429 &c->buffer->pos[i].y_advance); 430 c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint, 431 c->buffer->props.direction, 432 &c->buffer->pos[i].x_offset, 433 &c->buffer->pos[i].y_offset); 434 435 } 436} 437 438static inline bool 439hb_ot_position_complex (hb_ot_shape_context_t *c) 440{ 441 bool ret = false; 442 unsigned int count = c->buffer->len; 443 444 switch (c->plan->shaper->zero_width_marks) 445 { 446 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY: 447 zero_mark_widths_by_gdef (c->buffer); 448 break; 449 450 /* Not currently used for any shaper: 451 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY: 452 zero_mark_widths_by_unicode (c->buffer); 453 break; 454 */ 455 456 default: 457 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE: 458 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE: 459 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE: 460 break; 461 } 462 463 if (hb_ot_layout_has_positioning (c->face)) 464 { 465 /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */ 466 467 for (unsigned int i = 0; i < count; i++) { 468 c->font->add_glyph_origin_for_direction (c->buffer->info[i].codepoint, 469 HB_DIRECTION_LTR, 470 &c->buffer->pos[i].x_offset, 471 &c->buffer->pos[i].y_offset); 472 } 473 474 c->plan->position (c->font, c->buffer); 475 476 for (unsigned int i = 0; i < count; i++) { 477 c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint, 478 HB_DIRECTION_LTR, 479 &c->buffer->pos[i].x_offset, 480 &c->buffer->pos[i].y_offset); 481 } 482 483 ret = true; 484 } 485 486 switch (c->plan->shaper->zero_width_marks) 487 { 488 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE: 489 zero_mark_widths_by_unicode (c->buffer); 490 break; 491 492 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE: 493 zero_mark_widths_by_gdef (c->buffer); 494 break; 495 496 default: 497 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE: 498 //case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY: 499 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY: 500 break; 501 } 502 503 return ret; 504} 505 506static inline void 507hb_ot_position (hb_ot_shape_context_t *c) 508{ 509 hb_ot_layout_position_start (c->font, c->buffer); 510 511 hb_ot_position_default (c); 512 513 hb_bool_t fallback = !hb_ot_position_complex (c); 514 515 hb_ot_layout_position_finish (c->font, c->buffer); 516 517 if (fallback && c->plan->shaper->fallback_position) 518 _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer); 519 520 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction)) 521 hb_buffer_reverse (c->buffer); 522 523 /* Visual fallback goes here. */ 524 525 if (fallback) 526 _hb_ot_shape_fallback_kern (c->plan, c->font, c->buffer); 527} 528 529 530/* Post-process */ 531 532static void 533hb_ot_hide_default_ignorables (hb_ot_shape_context_t *c) 534{ 535 if (c->buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) 536 return; 537 538 hb_codepoint_t space; 539 enum { 540 SPACE_DONT_KNOW, 541 SPACE_AVAILABLE, 542 SPACE_UNAVAILABLE 543 } space_status = SPACE_DONT_KNOW; 544 545 unsigned int count = c->buffer->len; 546 hb_glyph_info_t *info = c->buffer->info; 547 hb_glyph_position_t *pos = c->buffer->pos; 548 unsigned int j = 0; 549 for (unsigned int i = 0; i < count; i++) 550 { 551 if (unlikely (!_hb_glyph_info_is_ligated (&info[i]) && 552 _hb_glyph_info_is_default_ignorable (&info[i]))) 553 { 554 if (space_status == SPACE_DONT_KNOW) 555 space_status = c->font->get_glyph (' ', 0, &space) ? SPACE_AVAILABLE : SPACE_UNAVAILABLE; 556 557 if (space_status == SPACE_AVAILABLE) 558 { 559 info[i].codepoint = space; 560 pos[i].x_advance = 0; 561 pos[i].y_advance = 0; 562 } 563 else 564 continue; /* Delete it. */ 565 } 566 if (j != i) 567 { 568 info[j] = info[i]; 569 pos[j] = pos[i]; 570 } 571 j++; 572 } 573 c->buffer->len = j; 574} 575 576 577/* Pull it all together! */ 578 579static void 580hb_ot_shape_internal (hb_ot_shape_context_t *c) 581{ 582 c->buffer->deallocate_var_all (); 583 584 /* Save the original direction, we use it later. */ 585 c->target_direction = c->buffer->props.direction; 586 587 HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props0); 588 HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props1); 589 590 c->buffer->clear_output (); 591 592 hb_set_unicode_props (c->buffer); 593 hb_insert_dotted_circle (c->buffer, c->font); 594 hb_form_clusters (c->buffer); 595 596 hb_ensure_native_direction (c->buffer); 597 598 hb_ot_substitute (c); 599 hb_ot_position (c); 600 601 hb_ot_hide_default_ignorables (c); 602 603 HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props1); 604 HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props0); 605 606 c->buffer->props.direction = c->target_direction; 607 608 c->buffer->deallocate_var_all (); 609} 610 611 612hb_bool_t 613_hb_ot_shape (hb_shape_plan_t *shape_plan, 614 hb_font_t *font, 615 hb_buffer_t *buffer, 616 const hb_feature_t *features, 617 unsigned int num_features) 618{ 619 hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features}; 620 hb_ot_shape_internal (&c); 621 622 return true; 623} 624 625 626void 627hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan, 628 hb_tag_t table_tag, 629 hb_set_t *lookup_indexes /* OUT */) 630{ 631 /* XXX Does the first part always succeed? */ 632 HB_SHAPER_DATA_GET (shape_plan)->collect_lookups (table_tag, lookup_indexes); 633} 634 635 636/* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */ 637static void 638add_char (hb_font_t *font, 639 hb_unicode_funcs_t *unicode, 640 hb_bool_t mirror, 641 hb_codepoint_t u, 642 hb_set_t *glyphs) 643{ 644 hb_codepoint_t glyph; 645 if (font->get_glyph (u, 0, &glyph)) 646 glyphs->add (glyph); 647 if (mirror) 648 { 649 hb_codepoint_t m = unicode->mirroring (u); 650 if (m != u && font->get_glyph (m, 0, &glyph)) 651 glyphs->add (glyph); 652 } 653} 654 655 656void 657hb_ot_shape_glyphs_closure (hb_font_t *font, 658 hb_buffer_t *buffer, 659 const hb_feature_t *features, 660 unsigned int num_features, 661 hb_set_t *glyphs) 662{ 663 hb_ot_shape_plan_t plan; 664 665 const char *shapers[] = {"ot", NULL}; 666 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props, 667 features, num_features, shapers); 668 669 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL; 670 671 unsigned int count = buffer->len; 672 for (unsigned int i = 0; i < count; i++) 673 add_char (font, buffer->unicode, mirror, buffer->info[i].codepoint, glyphs); 674 675 hb_set_t lookups; 676 lookups.init (); 677 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, &lookups); 678 679 /* And find transitive closure. */ 680 hb_set_t copy; 681 copy.init (); 682 do { 683 copy.set (glyphs); 684 for (hb_codepoint_t lookup_index = -1; hb_set_next (&lookups, &lookup_index);) 685 hb_ot_layout_lookup_substitute_closure (font->face, lookup_index, glyphs); 686 } while (!copy.is_equal (glyphs)); 687 688 hb_shape_plan_destroy (shape_plan); 689} 690