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-unicode-private.hh" 41 #include "hb-set-private.hh" 42 43 44 static hb_tag_t common_features[] = { 45 HB_TAG('c','c','m','p'), 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'), 51 }; 52 53 54 static hb_tag_t horizontal_features[] = { 55 HB_TAG('c','a','l','t'), 56 HB_TAG('c','l','i','g'), 57 HB_TAG('c','u','r','s'), 58 HB_TAG('k','e','r','n'), 59 HB_TAG('r','c','l','t'), 60 }; 61 62 static hb_tag_t vertical_features[] = { 63 HB_TAG('v','e','r','t'), 64 }; 65 66 67 68 static void 69 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner, 70 const hb_segment_properties_t *props, 71 const hb_feature_t *user_features, 72 unsigned int num_user_features) 73 { 74 hb_ot_map_builder_t *map = &planner->map; 75 76 switch (props->direction) { 77 case HB_DIRECTION_LTR: 78 map->add_global_bool_feature (HB_TAG ('l','t','r','a')); 79 map->add_global_bool_feature (HB_TAG ('l','t','r','m')); 80 break; 81 case HB_DIRECTION_RTL: 82 map->add_global_bool_feature (HB_TAG ('r','t','l','a')); 83 map->add_feature (HB_TAG ('r','t','l','m'), 1, F_NONE); 84 break; 85 case HB_DIRECTION_TTB: 86 case HB_DIRECTION_BTT: 87 case HB_DIRECTION_INVALID: 88 default: 89 break; 90 } 91 92 map->add_feature (HB_TAG ('f','r','a','c'), 1, F_NONE); 93 map->add_feature (HB_TAG ('n','u','m','r'), 1, F_NONE); 94 map->add_feature (HB_TAG ('d','n','o','m'), 1, F_NONE); 95 96 if (planner->shaper->collect_features) 97 planner->shaper->collect_features (planner); 98 99 for (unsigned int i = 0; i < ARRAY_LENGTH (common_features); i++) 100 map->add_global_bool_feature (common_features[i]); 101 102 if (HB_DIRECTION_IS_HORIZONTAL (props->direction)) 103 for (unsigned int i = 0; i < ARRAY_LENGTH (horizontal_features); i++) 104 map->add_feature (horizontal_features[i], 1, F_GLOBAL | 105 (horizontal_features[i] == HB_TAG('k','e','r','n') ? 106 F_HAS_FALLBACK : F_NONE)); 107 else 108 for (unsigned int i = 0; i < ARRAY_LENGTH (vertical_features); i++) 109 map->add_feature (vertical_features[i], 1, F_GLOBAL | 110 (vertical_features[i] == HB_TAG('v','k','r','n') ? 111 F_HAS_FALLBACK : F_NONE)); 112 113 if (planner->shaper->override_features) 114 planner->shaper->override_features (planner); 115 116 for (unsigned int i = 0; i < num_user_features; i++) { 117 const hb_feature_t *feature = &user_features[i]; 118 map->add_feature (feature->tag, feature->value, 119 (feature->start == 0 && feature->end == (unsigned int) -1) ? 120 F_GLOBAL : F_NONE); 121 } 122 } 123 124 125 /* 126 * shaper face data 127 */ 128 129 hb_ot_shaper_face_data_t * 130 _hb_ot_shaper_face_data_create (hb_face_t *face) 131 { 132 return _hb_ot_layout_create (face); 133 } 134 135 void 136 _hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data) 137 { 138 _hb_ot_layout_destroy (data); 139 } 140 141 142 /* 143 * shaper font data 144 */ 145 146 struct hb_ot_shaper_font_data_t {}; 147 148 hb_ot_shaper_font_data_t * 149 _hb_ot_shaper_font_data_create (hb_font_t *font) 150 { 151 return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED; 152 } 153 154 void 155 _hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data) 156 { 157 } 158 159 160 /* 161 * shaper shape_plan data 162 */ 163 164 hb_ot_shaper_shape_plan_data_t * 165 _hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan, 166 const hb_feature_t *user_features, 167 unsigned int num_user_features) 168 { 169 hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t)); 170 if (unlikely (!plan)) 171 return NULL; 172 173 hb_ot_shape_planner_t planner (shape_plan); 174 175 planner.shaper = hb_ot_shape_complex_categorize (&planner); 176 177 hb_ot_shape_collect_features (&planner, &shape_plan->props, user_features, num_user_features); 178 179 planner.compile (*plan); 180 181 if (plan->shaper->data_create) { 182 plan->data = plan->shaper->data_create (plan); 183 if (unlikely (!plan->data)) 184 return NULL; 185 } 186 187 return plan; 188 } 189 190 void 191 _hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan) 192 { 193 if (plan->shaper->data_destroy) 194 plan->shaper->data_destroy (const_cast<void *> (plan->data)); 195 196 plan->finish (); 197 198 free (plan); 199 } 200 201 202 /* 203 * shaper 204 */ 205 206 struct hb_ot_shape_context_t 207 { 208 hb_ot_shape_plan_t *plan; 209 hb_font_t *font; 210 hb_face_t *face; 211 hb_buffer_t *buffer; 212 const hb_feature_t *user_features; 213 unsigned int num_user_features; 214 215 /* Transient stuff */ 216 hb_direction_t target_direction; 217 }; 218 219 220 221 /* Main shaper */ 222 223 224 /* Prepare */ 225 226 static void 227 hb_set_unicode_props (hb_buffer_t *buffer) 228 { 229 unsigned int count = buffer->len; 230 hb_glyph_info_t *info = buffer->info; 231 for (unsigned int i = 0; i < count; i++) 232 _hb_glyph_info_set_unicode_props (&info[i], buffer->unicode); 233 } 234 235 static void 236 hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font) 237 { 238 if (!(buffer->flags & HB_BUFFER_FLAG_BOT) || 239 _hb_glyph_info_get_general_category (&buffer->info[0]) != 240 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) 241 return; 242 243 if (!font->has_glyph (0x25CCu)) 244 return; 245 246 hb_glyph_info_t dottedcircle; 247 dottedcircle.codepoint = 0x25CCu; 248 _hb_glyph_info_set_unicode_props (&dottedcircle, buffer->unicode); 249 250 buffer->clear_output (); 251 252 buffer->idx = 0; 253 hb_glyph_info_t info = dottedcircle; 254 info.cluster = buffer->cur().cluster; 255 info.mask = buffer->cur().mask; 256 buffer->output_info (info); 257 while (buffer->idx < buffer->len) 258 buffer->next_glyph (); 259 260 buffer->swap_buffers (); 261 } 262 263 static void 264 hb_form_clusters (hb_buffer_t *buffer) 265 { 266 unsigned int count = buffer->len; 267 hb_glyph_info_t *info = buffer->info; 268 for (unsigned int i = 1; i < count; i++) 269 if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i]))) 270 buffer->merge_clusters (i - 1, i + 1); 271 } 272 273 static void 274 hb_ensure_native_direction (hb_buffer_t *buffer) 275 { 276 hb_direction_t direction = buffer->props.direction; 277 278 /* TODO vertical: 279 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType 280 * Ogham fonts are supposed to be implemented BTT or not. Need to research that 281 * first. */ 282 if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) || 283 (HB_DIRECTION_IS_VERTICAL (direction) && direction != HB_DIRECTION_TTB)) 284 { 285 hb_buffer_reverse_clusters (buffer); 286 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction); 287 } 288 } 289 290 291 /* Substitute */ 292 293 static inline void 294 hb_ot_mirror_chars (hb_ot_shape_context_t *c) 295 { 296 if (HB_DIRECTION_IS_FORWARD (c->target_direction)) 297 return; 298 299 hb_buffer_t *buffer = c->buffer; 300 hb_unicode_funcs_t *unicode = buffer->unicode; 301 hb_mask_t rtlm_mask = c->plan->rtlm_mask; 302 303 unsigned int count = buffer->len; 304 hb_glyph_info_t *info = buffer->info; 305 for (unsigned int i = 0; i < count; i++) { 306 hb_codepoint_t codepoint = unicode->mirroring (info[i].codepoint); 307 if (likely (codepoint == info[i].codepoint)) 308 info[i].mask |= rtlm_mask; 309 else 310 info[i].codepoint = codepoint; 311 } 312 } 313 314 static inline void 315 hb_ot_shape_setup_masks_fraction (hb_ot_shape_context_t *c) 316 { 317 if (!c->plan->has_frac) 318 return; 319 320 hb_buffer_t *buffer = c->buffer; 321 322 /* TODO look in pre/post context text also. */ 323 unsigned int count = buffer->len; 324 hb_glyph_info_t *info = buffer->info; 325 for (unsigned int i = 0; i < count; i++) 326 { 327 if (info[i].codepoint == 0x2044u) /* FRACTION SLASH */ 328 { 329 unsigned int start = i, end = i + 1; 330 while (start && 331 _hb_glyph_info_get_general_category (&info[start - 1]) == 332 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER) 333 start--; 334 while (end < count && 335 _hb_glyph_info_get_general_category (&info[end]) == 336 HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER) 337 end++; 338 339 for (unsigned int j = start; j < i; j++) 340 info[j].mask |= c->plan->numr_mask | c->plan->frac_mask; 341 info[i].mask |= c->plan->frac_mask; 342 for (unsigned int j = i + 1; j < end; j++) 343 info[j].mask |= c->plan->frac_mask | c->plan->dnom_mask; 344 345 i = end - 1; 346 } 347 } 348 } 349 350 static inline void 351 hb_ot_shape_initialize_masks (hb_ot_shape_context_t *c) 352 { 353 hb_ot_map_t *map = &c->plan->map; 354 hb_buffer_t *buffer = c->buffer; 355 356 hb_mask_t global_mask = map->get_global_mask (); 357 buffer->reset_masks (global_mask); 358 } 359 360 static inline void 361 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c) 362 { 363 hb_ot_map_t *map = &c->plan->map; 364 hb_buffer_t *buffer = c->buffer; 365 366 hb_ot_shape_setup_masks_fraction (c); 367 368 if (c->plan->shaper->setup_masks) 369 c->plan->shaper->setup_masks (c->plan, buffer, c->font); 370 371 for (unsigned int i = 0; i < c->num_user_features; i++) 372 { 373 const hb_feature_t *feature = &c->user_features[i]; 374 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) { 375 unsigned int shift; 376 hb_mask_t mask = map->get_mask (feature->tag, &shift); 377 buffer->set_masks (feature->value << shift, mask, feature->start, feature->end); 378 } 379 } 380 } 381 382 static inline void 383 hb_ot_map_glyphs_fast (hb_buffer_t *buffer) 384 { 385 /* Normalization process sets up glyph_index(), we just copy it. */ 386 unsigned int count = buffer->len; 387 hb_glyph_info_t *info = buffer->info; 388 for (unsigned int i = 0; i < count; i++) 389 info[i].codepoint = info[i].glyph_index(); 390 } 391 392 static inline void 393 hb_synthesize_glyph_classes (hb_ot_shape_context_t *c) 394 { 395 unsigned int count = c->buffer->len; 396 hb_glyph_info_t *info = c->buffer->info; 397 for (unsigned int i = 0; i < count; i++) 398 { 399 hb_ot_layout_glyph_class_mask_t klass; 400 401 /* Never mark default-ignorables as marks. 402 * They won't get in the way of lookups anyway, 403 * but having them as mark will cause them to be skipped 404 * over if the lookup-flag says so, but at least for the 405 * Mongolian variation selectors, looks like Uniscribe 406 * marks them as non-mark. Some Mongolian fonts without 407 * GDEF rely on this. Another notable character that 408 * this applies to is COMBINING GRAPHEME JOINER. */ 409 klass = (_hb_glyph_info_get_general_category (&info[i]) != 410 HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK || 411 _hb_glyph_info_is_default_ignorable (&info[i])) ? 412 HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH : 413 HB_OT_LAYOUT_GLYPH_PROPS_MARK; 414 _hb_glyph_info_set_glyph_props (&info[i], klass); 415 } 416 } 417 418 static inline void 419 hb_ot_substitute_default (hb_ot_shape_context_t *c) 420 { 421 hb_buffer_t *buffer = c->buffer; 422 423 if (c->plan->shaper->preprocess_text) 424 c->plan->shaper->preprocess_text (c->plan, buffer, c->font); 425 426 hb_ot_shape_initialize_masks (c); 427 428 hb_ot_mirror_chars (c); 429 430 HB_BUFFER_ALLOCATE_VAR (buffer, glyph_index); 431 432 _hb_ot_shape_normalize (c->plan, buffer, c->font); 433 434 hb_ot_shape_setup_masks (c); 435 436 /* This is unfortunate to go here, but necessary... */ 437 if (!hb_ot_layout_has_positioning (c->face)) 438 _hb_ot_shape_fallback_position_recategorize_marks (c->plan, c->font, buffer); 439 440 hb_ot_map_glyphs_fast (buffer); 441 442 HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_index); 443 } 444 445 static inline void 446 hb_ot_substitute_complex (hb_ot_shape_context_t *c) 447 { 448 hb_buffer_t *buffer = c->buffer; 449 450 hb_ot_layout_substitute_start (c->font, buffer); 451 452 if (!hb_ot_layout_has_glyph_classes (c->face)) 453 hb_synthesize_glyph_classes (c); 454 455 c->plan->substitute (c->font, buffer); 456 457 hb_ot_layout_substitute_finish (c->font, buffer); 458 459 return; 460 } 461 462 static inline void 463 hb_ot_substitute (hb_ot_shape_context_t *c) 464 { 465 hb_ot_substitute_default (c); 466 hb_ot_substitute_complex (c); 467 } 468 469 /* Position */ 470 471 static inline void 472 adjust_mark_offsets (hb_glyph_position_t *pos) 473 { 474 pos->x_offset -= pos->x_advance; 475 pos->y_offset -= pos->y_advance; 476 } 477 478 static inline void 479 zero_mark_width (hb_glyph_position_t *pos) 480 { 481 pos->x_advance = 0; 482 pos->y_advance = 0; 483 } 484 485 static inline void 486 zero_mark_widths_by_unicode (hb_buffer_t *buffer, bool adjust_offsets) 487 { 488 unsigned int count = buffer->len; 489 hb_glyph_info_t *info = buffer->info; 490 for (unsigned int i = 0; i < count; i++) 491 if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) 492 { 493 if (adjust_offsets) 494 adjust_mark_offsets (&buffer->pos[i]); 495 zero_mark_width (&buffer->pos[i]); 496 } 497 } 498 499 static inline void 500 zero_mark_widths_by_gdef (hb_buffer_t *buffer, bool adjust_offsets) 501 { 502 unsigned int count = buffer->len; 503 hb_glyph_info_t *info = buffer->info; 504 for (unsigned int i = 0; i < count; i++) 505 if (_hb_glyph_info_is_mark (&info[i])) 506 { 507 if (adjust_offsets) 508 adjust_mark_offsets (&buffer->pos[i]); 509 zero_mark_width (&buffer->pos[i]); 510 } 511 } 512 513 static inline void 514 hb_ot_position_default (hb_ot_shape_context_t *c) 515 { 516 hb_direction_t direction = c->buffer->props.direction; 517 unsigned int count = c->buffer->len; 518 hb_glyph_info_t *info = c->buffer->info; 519 hb_glyph_position_t *pos = c->buffer->pos; 520 for (unsigned int i = 0; i < count; i++) 521 { 522 c->font->get_glyph_advance_for_direction (info[i].codepoint, 523 direction, 524 &pos[i].x_advance, 525 &pos[i].y_advance); 526 c->font->subtract_glyph_origin_for_direction (info[i].codepoint, 527 direction, 528 &pos[i].x_offset, 529 &pos[i].y_offset); 530 531 } 532 } 533 534 static inline bool 535 hb_ot_position_complex (hb_ot_shape_context_t *c) 536 { 537 bool ret = false; 538 unsigned int count = c->buffer->len; 539 bool has_positioning = hb_ot_layout_has_positioning (c->face); 540 /* If the font has no GPOS, AND, no fallback positioning will 541 * happen, AND, direction is forward, then when zeroing mark 542 * widths, we shift the mark with it, such that the mark 543 * is positioned hanging over the previous glyph. When 544 * direction is backward we don't shift and it will end up 545 * hanging over the next glyph after the final reordering. 546 * If fallback positinoing happens or GPOS is present, we don't 547 * care. 548 */ 549 bool adjust_offsets_when_zeroing = !(has_positioning || c->plan->shaper->fallback_position || 550 HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction)); 551 552 switch (c->plan->shaper->zero_width_marks) 553 { 554 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY: 555 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing); 556 break; 557 558 /* Not currently used for any shaper: 559 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY: 560 zero_mark_widths_by_unicode (c->buffer, adjust_offsets_when_zeroing); 561 break; 562 */ 563 564 default: 565 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE: 566 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE: 567 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE: 568 break; 569 } 570 571 if (has_positioning) 572 { 573 hb_glyph_info_t *info = c->buffer->info; 574 hb_glyph_position_t *pos = c->buffer->pos; 575 576 /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */ 577 578 for (unsigned int i = 0; i < count; i++) { 579 c->font->add_glyph_origin_for_direction (info[i].codepoint, 580 HB_DIRECTION_LTR, 581 &pos[i].x_offset, 582 &pos[i].y_offset); 583 } 584 585 c->plan->position (c->font, c->buffer); 586 587 for (unsigned int i = 0; i < count; i++) { 588 c->font->subtract_glyph_origin_for_direction (info[i].codepoint, 589 HB_DIRECTION_LTR, 590 &pos[i].x_offset, 591 &pos[i].y_offset); 592 } 593 594 ret = true; 595 } 596 597 switch (c->plan->shaper->zero_width_marks) 598 { 599 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE: 600 zero_mark_widths_by_unicode (c->buffer, adjust_offsets_when_zeroing); 601 break; 602 603 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE: 604 zero_mark_widths_by_gdef (c->buffer, adjust_offsets_when_zeroing); 605 break; 606 607 default: 608 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE: 609 //case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY: 610 case HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY: 611 break; 612 } 613 614 return ret; 615 } 616 617 static inline void 618 hb_ot_position (hb_ot_shape_context_t *c) 619 { 620 hb_ot_layout_position_start (c->font, c->buffer); 621 622 hb_ot_position_default (c); 623 624 hb_bool_t fallback = !hb_ot_position_complex (c); 625 626 hb_ot_layout_position_finish (c->font, c->buffer); 627 628 if (fallback && c->plan->shaper->fallback_position) 629 _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer); 630 631 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction)) 632 hb_buffer_reverse (c->buffer); 633 634 /* Visual fallback goes here. */ 635 636 if (fallback) 637 _hb_ot_shape_fallback_kern (c->plan, c->font, c->buffer); 638 } 639 640 641 /* Post-process */ 642 643 static void 644 hb_ot_hide_default_ignorables (hb_ot_shape_context_t *c) 645 { 646 if (c->buffer->flags & HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES) 647 return; 648 649 hb_codepoint_t space; 650 enum { 651 SPACE_DONT_KNOW, 652 SPACE_AVAILABLE, 653 SPACE_UNAVAILABLE 654 } space_status = SPACE_DONT_KNOW; 655 656 unsigned int count = c->buffer->len; 657 hb_glyph_info_t *info = c->buffer->info; 658 hb_glyph_position_t *pos = c->buffer->pos; 659 unsigned int j = 0; 660 for (unsigned int i = 0; i < count; i++) 661 { 662 if (unlikely (!_hb_glyph_info_ligated (&info[i]) && 663 _hb_glyph_info_is_default_ignorable (&info[i]))) 664 { 665 if (space_status == SPACE_DONT_KNOW) 666 space_status = c->font->get_glyph (' ', 0, &space) ? SPACE_AVAILABLE : SPACE_UNAVAILABLE; 667 668 if (space_status == SPACE_AVAILABLE) 669 { 670 info[i].codepoint = space; 671 pos[i].x_advance = 0; 672 pos[i].y_advance = 0; 673 } 674 else 675 continue; /* Delete it. */ 676 } 677 if (j != i) 678 { 679 info[j] = info[i]; 680 pos[j] = pos[i]; 681 } 682 j++; 683 } 684 c->buffer->len = j; 685 } 686 687 688 /* Pull it all together! */ 689 690 static void 691 hb_ot_shape_internal (hb_ot_shape_context_t *c) 692 { 693 c->buffer->deallocate_var_all (); 694 695 /* Save the original direction, we use it later. */ 696 c->target_direction = c->buffer->props.direction; 697 698 _hb_buffer_allocate_unicode_vars (c->buffer); 699 700 c->buffer->clear_output (); 701 702 hb_set_unicode_props (c->buffer); 703 hb_insert_dotted_circle (c->buffer, c->font); 704 hb_form_clusters (c->buffer); 705 706 hb_ensure_native_direction (c->buffer); 707 708 hb_ot_substitute (c); 709 hb_ot_position (c); 710 711 hb_ot_hide_default_ignorables (c); 712 713 _hb_buffer_deallocate_unicode_vars (c->buffer); 714 715 c->buffer->props.direction = c->target_direction; 716 717 c->buffer->deallocate_var_all (); 718 } 719 720 721 hb_bool_t 722 _hb_ot_shape (hb_shape_plan_t *shape_plan, 723 hb_font_t *font, 724 hb_buffer_t *buffer, 725 const hb_feature_t *features, 726 unsigned int num_features) 727 { 728 hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features}; 729 hb_ot_shape_internal (&c); 730 731 return true; 732 } 733 734 735 void 736 hb_ot_shape_plan_collect_lookups (hb_shape_plan_t *shape_plan, 737 hb_tag_t table_tag, 738 hb_set_t *lookup_indexes /* OUT */) 739 { 740 /* XXX Does the first part always succeed? */ 741 HB_SHAPER_DATA_GET (shape_plan)->collect_lookups (table_tag, lookup_indexes); 742 } 743 744 745 /* TODO Move this to hb-ot-shape-normalize, make it do decompose, and make it public. */ 746 static void 747 add_char (hb_font_t *font, 748 hb_unicode_funcs_t *unicode, 749 hb_bool_t mirror, 750 hb_codepoint_t u, 751 hb_set_t *glyphs) 752 { 753 hb_codepoint_t glyph; 754 if (font->get_glyph (u, 0, &glyph)) 755 glyphs->add (glyph); 756 if (mirror) 757 { 758 hb_codepoint_t m = unicode->mirroring (u); 759 if (m != u && font->get_glyph (m, 0, &glyph)) 760 glyphs->add (glyph); 761 } 762 } 763 764 765 void 766 hb_ot_shape_glyphs_closure (hb_font_t *font, 767 hb_buffer_t *buffer, 768 const hb_feature_t *features, 769 unsigned int num_features, 770 hb_set_t *glyphs) 771 { 772 hb_ot_shape_plan_t plan; 773 774 const char *shapers[] = {"ot", NULL}; 775 hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached (font->face, &buffer->props, 776 features, num_features, shapers); 777 778 bool mirror = hb_script_get_horizontal_direction (buffer->props.script) == HB_DIRECTION_RTL; 779 780 unsigned int count = buffer->len; 781 hb_glyph_info_t *info = buffer->info; 782 for (unsigned int i = 0; i < count; i++) 783 add_char (font, buffer->unicode, mirror, info[i].codepoint, glyphs); 784 785 hb_set_t lookups; 786 lookups.init (); 787 hb_ot_shape_plan_collect_lookups (shape_plan, HB_OT_TAG_GSUB, &lookups); 788 789 /* And find transitive closure. */ 790 hb_set_t copy; 791 copy.init (); 792 do { 793 copy.set (glyphs); 794 for (hb_codepoint_t lookup_index = -1; hb_set_next (&lookups, &lookup_index);) 795 hb_ot_layout_lookup_substitute_closure (font->face, lookup_index, glyphs); 796 } while (!copy.is_equal (glyphs)); 797 798 hb_shape_plan_destroy (shape_plan); 799 } 800
