hb-ot-layout-gsubgpos-private.hh revision 41ae674f6871f43d0a6e4ca67a747074d63ae576
1/* 2 * Copyright © 2007,2008,2009,2010 Red Hat, Inc. 3 * Copyright © 2010 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#ifndef HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH 30#define HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH 31 32#include "hb-buffer-private.hh" 33#include "hb-ot-layout-gdef-table.hh" 34 35 36/* buffer var allocations */ 37#define lig_id() var2.u8[2] /* unique ligature id */ 38#define lig_comp() var2.u8[3] /* component number in the ligature (0 = base) */ 39 40static inline uint8_t allocate_lig_id (hb_buffer_t *buffer) { 41 uint8_t lig_id = buffer->next_serial (); 42 if (unlikely (!lig_id)) lig_id = buffer->next_serial (); /* in case of overflow */ 43 return lig_id; 44} 45 46 47 48#ifndef HB_DEBUG_APPLY 49#define HB_DEBUG_APPLY (HB_DEBUG+0) 50#endif 51 52#define TRACE_APPLY() \ 53 hb_auto_trace_t<HB_DEBUG_APPLY> trace (&c->debug_depth, "APPLY", this, NULL, HB_FUNC); 54 55 56 57struct hb_apply_context_t 58{ 59 unsigned int debug_depth; 60 hb_font_t *font; 61 hb_face_t *face; 62 hb_buffer_t *buffer; 63 hb_direction_t direction; 64 hb_mask_t lookup_mask; 65 unsigned int context_length; 66 unsigned int nesting_level_left; 67 unsigned int lookup_props; 68 unsigned int property; /* propety of first glyph */ 69 70 71 hb_apply_context_t (hb_font_t *font_, 72 hb_face_t *face_, 73 hb_buffer_t *buffer_, 74 hb_mask_t lookup_mask_, 75 const Lookup &l, 76 unsigned int context_length_ = NO_CONTEXT, 77 unsigned int nesting_level_left_ = MAX_NESTING_LEVEL) : 78 font (font_), face (face_), buffer (buffer_), 79 direction (buffer_->props.direction), 80 lookup_mask (lookup_mask_), 81 context_length (context_length_), 82 nesting_level_left (nesting_level_left_), 83 lookup_props (l.get_props ()), 84 property (0) {} 85 86 hb_apply_context_t (const hb_apply_context_t &c, const Lookup &l) { 87 *this = c; 88 nesting_level_left--; 89 lookup_props = l.get_props (); 90 } 91 92 struct mark_skipping_forward_iterator_t 93 { 94 inline mark_skipping_forward_iterator_t (hb_apply_context_t *c_, 95 unsigned int start_index_, 96 unsigned int num_items_) 97 { 98 c = c_; 99 idx = start_index_; 100 num_items = num_items_; 101 end = MIN (c->buffer->len, c->buffer->idx + c->context_length); 102 } 103 inline bool has_no_chance (void) const 104 { 105 return unlikely (num_items && idx + num_items >= end); 106 } 107 inline bool next (unsigned int *property_out, 108 unsigned int lookup_props) 109 { 110 assert (num_items > 0); 111 do 112 { 113 if (has_no_chance ()) 114 return false; 115 idx++; 116 } while (_hb_ot_layout_skip_mark (c->face, &c->buffer->info[idx], lookup_props, property_out)); 117 num_items--; 118 return true; 119 } 120 inline bool next (unsigned int *property_out = NULL) 121 { 122 return next (property_out, c->lookup_props); 123 } 124 125 unsigned int idx; 126 private: 127 hb_apply_context_t *c; 128 unsigned int num_items; 129 unsigned int end; 130 }; 131 132 struct mark_skipping_backward_iterator_t 133 { 134 inline mark_skipping_backward_iterator_t (hb_apply_context_t *c_, 135 unsigned int start_index_, 136 unsigned int num_items_) 137 { 138 c = c_; 139 idx = start_index_; 140 num_items = num_items_; 141 } 142 inline bool has_no_chance (void) const 143 { 144 return unlikely (idx < num_items); 145 } 146 inline bool prev (unsigned int *property_out, 147 unsigned int lookup_props) 148 { 149 assert (num_items > 0); 150 do 151 { 152 if (has_no_chance ()) 153 return false; 154 idx--; 155 } while (_hb_ot_layout_skip_mark (c->face, &c->buffer->out_info[idx], lookup_props, property_out)); 156 num_items--; 157 return true; 158 } 159 inline bool prev (unsigned int *property_out = NULL) 160 { 161 return prev (property_out, c->lookup_props); 162 } 163 164 unsigned int idx; 165 private: 166 hb_apply_context_t *c; 167 unsigned int num_items; 168 }; 169 170 inline bool should_mark_skip_current_glyph (void) const 171 { 172 return _hb_ot_layout_skip_mark (face, &buffer->info[buffer->idx], lookup_props, NULL); 173 } 174 175 176 177 inline void replace_glyph (hb_codepoint_t glyph_index) const 178 { 179 clear_property (); 180 buffer->replace_glyph (glyph_index); 181 } 182 inline void replace_glyphs_be16 (unsigned int num_in, 183 unsigned int num_out, 184 const uint16_t *glyph_data_be) const 185 { 186 clear_property (); 187 buffer->replace_glyphs_be16 (num_in, num_out, glyph_data_be); 188 } 189 190 inline void guess_glyph_class (unsigned int klass) 191 { 192 /* XXX if ! has gdef */ 193 buffer->info[buffer->idx].props_cache() = klass; 194 } 195 196 private: 197 inline void clear_property (void) const 198 { 199 /* XXX if has gdef */ 200 buffer->info[buffer->idx].props_cache() = 0; 201 } 202}; 203 204 205 206typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data); 207typedef bool (*apply_lookup_func_t) (hb_apply_context_t *c, unsigned int lookup_index); 208 209struct ContextFuncs 210{ 211 match_func_t match; 212 apply_lookup_func_t apply; 213}; 214 215 216static inline bool match_glyph (hb_codepoint_t glyph_id, const USHORT &value, const void *data HB_UNUSED) 217{ 218 return glyph_id == value; 219} 220 221static inline bool match_class (hb_codepoint_t glyph_id, const USHORT &value, const void *data) 222{ 223 const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data); 224 return class_def.get_class (glyph_id) == value; 225} 226 227static inline bool match_coverage (hb_codepoint_t glyph_id, const USHORT &value, const void *data) 228{ 229 const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value; 230 return (data+coverage) (glyph_id) != NOT_COVERED; 231} 232 233 234static inline bool match_input (hb_apply_context_t *c, 235 unsigned int count, /* Including the first glyph (not matched) */ 236 const USHORT input[], /* Array of input values--start with second glyph */ 237 match_func_t match_func, 238 const void *match_data, 239 unsigned int *context_length_out) 240{ 241 hb_apply_context_t::mark_skipping_forward_iterator_t skippy_iter (c, c->buffer->idx, count - 1); 242 if (skippy_iter.has_no_chance ()) 243 return false; 244 245 for (unsigned int i = 1; i < count; i++) 246 { 247 if (!skippy_iter.next ()) 248 return false; 249 250 if (likely (!match_func (c->buffer->info[skippy_iter.idx].codepoint, input[i - 1], match_data))) 251 return false; 252 } 253 254 *context_length_out = skippy_iter.idx - c->buffer->idx + 1; 255 256 return true; 257} 258 259static inline bool match_backtrack (hb_apply_context_t *c, 260 unsigned int count, 261 const USHORT backtrack[], 262 match_func_t match_func, 263 const void *match_data) 264{ 265 hb_apply_context_t::mark_skipping_backward_iterator_t skippy_iter (c, c->buffer->backtrack_len (), count); 266 if (skippy_iter.has_no_chance ()) 267 return false; 268 269 for (unsigned int i = 0; i < count; i++) 270 { 271 if (!skippy_iter.prev ()) 272 return false; 273 274 if (likely (!match_func (c->buffer->out_info[skippy_iter.idx].codepoint, backtrack[i], match_data))) 275 return false; 276 } 277 278 return true; 279} 280 281static inline bool match_lookahead (hb_apply_context_t *c, 282 unsigned int count, 283 const USHORT lookahead[], 284 match_func_t match_func, 285 const void *match_data, 286 unsigned int offset) 287{ 288 hb_apply_context_t::mark_skipping_forward_iterator_t skippy_iter (c, c->buffer->idx + offset - 1, count); 289 if (skippy_iter.has_no_chance ()) 290 return false; 291 292 for (unsigned int i = 0; i < count; i++) 293 { 294 if (!skippy_iter.next ()) 295 return false; 296 297 if (likely (!match_func (c->buffer->info[skippy_iter.idx].codepoint, lookahead[i], match_data))) 298 return false; 299 } 300 301 return true; 302} 303 304 305 306struct LookupRecord 307{ 308 inline bool sanitize (hb_sanitize_context_t *c) { 309 TRACE_SANITIZE (); 310 return c->check_struct (this); 311 } 312 313 USHORT sequenceIndex; /* Index into current glyph 314 * sequence--first glyph = 0 */ 315 USHORT lookupListIndex; /* Lookup to apply to that 316 * position--zero--based */ 317 public: 318 DEFINE_SIZE_STATIC (4); 319}; 320 321 322 323static inline bool apply_lookup (hb_apply_context_t *c, 324 unsigned int count, /* Including the first glyph */ 325 unsigned int lookupCount, 326 const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */ 327 apply_lookup_func_t apply_func) 328{ 329 unsigned int end = MIN (c->buffer->len, c->buffer->idx + c->context_length); 330 if (unlikely (count == 0 || c->buffer->idx + count > end)) 331 return false; 332 333 /* TODO We don't support lookupRecord arrays that are not increasing: 334 * Should be easy for in_place ones at least. */ 335 336 /* Note: If sublookup is reverse, it will underflow after the first loop 337 * and we jump out of it. Not entirely disastrous. So we don't check 338 * for reverse lookup here. 339 */ 340 for (unsigned int i = 0; i < count; /* NOP */) 341 { 342 if (unlikely (c->buffer->idx == end)) 343 return true; 344 while (c->should_mark_skip_current_glyph ()) 345 { 346 /* No lookup applied for this index */ 347 c->buffer->next_glyph (); 348 if (unlikely (c->buffer->idx == end)) 349 return true; 350 } 351 352 if (lookupCount && i == lookupRecord->sequenceIndex) 353 { 354 unsigned int old_pos = c->buffer->idx; 355 356 /* Apply a lookup */ 357 bool done = apply_func (c, lookupRecord->lookupListIndex); 358 359 lookupRecord++; 360 lookupCount--; 361 /* Err, this is wrong if the lookup jumped over some glyphs */ 362 i += c->buffer->idx - old_pos; 363 if (unlikely (c->buffer->idx == end)) 364 return true; 365 366 if (!done) 367 goto not_applied; 368 } 369 else 370 { 371 not_applied: 372 /* No lookup applied for this index */ 373 c->buffer->next_glyph (); 374 i++; 375 } 376 } 377 378 return true; 379} 380 381 382 383/* Contextual lookups */ 384 385struct ContextLookupContext 386{ 387 ContextFuncs funcs; 388 const void *match_data; 389}; 390 391static inline bool context_lookup (hb_apply_context_t *c, 392 unsigned int inputCount, /* Including the first glyph (not matched) */ 393 const USHORT input[], /* Array of input values--start with second glyph */ 394 unsigned int lookupCount, 395 const LookupRecord lookupRecord[], 396 ContextLookupContext &lookup_context) 397{ 398 hb_apply_context_t new_context = *c; 399 return match_input (c, 400 inputCount, input, 401 lookup_context.funcs.match, lookup_context.match_data, 402 &new_context.context_length) 403 && apply_lookup (&new_context, 404 inputCount, 405 lookupCount, lookupRecord, 406 lookup_context.funcs.apply); 407} 408 409struct Rule 410{ 411 friend struct RuleSet; 412 413 private: 414 inline bool apply (hb_apply_context_t *c, ContextLookupContext &lookup_context) const 415 { 416 TRACE_APPLY (); 417 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (input, input[0].static_size * (inputCount ? inputCount - 1 : 0)); 418 return context_lookup (c, 419 inputCount, input, 420 lookupCount, lookupRecord, 421 lookup_context); 422 } 423 424 public: 425 inline bool sanitize (hb_sanitize_context_t *c) { 426 TRACE_SANITIZE (); 427 return inputCount.sanitize (c) 428 && lookupCount.sanitize (c) 429 && c->check_range (input, 430 input[0].static_size * inputCount 431 + lookupRecordX[0].static_size * lookupCount); 432 } 433 434 private: 435 USHORT inputCount; /* Total number of glyphs in input 436 * glyph sequence--includes the first 437 * glyph */ 438 USHORT lookupCount; /* Number of LookupRecords */ 439 USHORT input[VAR]; /* Array of match inputs--start with 440 * second glyph */ 441 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in 442 * design order */ 443 public: 444 DEFINE_SIZE_ARRAY2 (4, input, lookupRecordX); 445}; 446 447struct RuleSet 448{ 449 inline bool apply (hb_apply_context_t *c, ContextLookupContext &lookup_context) const 450 { 451 TRACE_APPLY (); 452 unsigned int num_rules = rule.len; 453 for (unsigned int i = 0; i < num_rules; i++) 454 { 455 if ((this+rule[i]).apply (c, lookup_context)) 456 return true; 457 } 458 459 return false; 460 } 461 462 inline bool sanitize (hb_sanitize_context_t *c) { 463 TRACE_SANITIZE (); 464 return rule.sanitize (c, this); 465 } 466 467 private: 468 OffsetArrayOf<Rule> 469 rule; /* Array of Rule tables 470 * ordered by preference */ 471 public: 472 DEFINE_SIZE_ARRAY (2, rule); 473}; 474 475 476struct ContextFormat1 477{ 478 friend struct Context; 479 480 private: 481 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 482 { 483 TRACE_APPLY (); 484 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->idx].codepoint); 485 if (likely (index == NOT_COVERED)) 486 return false; 487 488 const RuleSet &rule_set = this+ruleSet[index]; 489 struct ContextLookupContext lookup_context = { 490 {match_glyph, apply_func}, 491 NULL 492 }; 493 return rule_set.apply (c, lookup_context); 494 } 495 496 inline bool sanitize (hb_sanitize_context_t *c) { 497 TRACE_SANITIZE (); 498 return coverage.sanitize (c, this) 499 && ruleSet.sanitize (c, this); 500 } 501 502 private: 503 USHORT format; /* Format identifier--format = 1 */ 504 OffsetTo<Coverage> 505 coverage; /* Offset to Coverage table--from 506 * beginning of table */ 507 OffsetArrayOf<RuleSet> 508 ruleSet; /* Array of RuleSet tables 509 * ordered by Coverage Index */ 510 public: 511 DEFINE_SIZE_ARRAY (6, ruleSet); 512}; 513 514 515struct ContextFormat2 516{ 517 friend struct Context; 518 519 private: 520 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 521 { 522 TRACE_APPLY (); 523 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->idx].codepoint); 524 if (likely (index == NOT_COVERED)) 525 return false; 526 527 const ClassDef &class_def = this+classDef; 528 index = class_def (c->buffer->info[c->buffer->idx].codepoint); 529 const RuleSet &rule_set = this+ruleSet[index]; 530 struct ContextLookupContext lookup_context = { 531 {match_class, apply_func}, 532 &class_def 533 }; 534 return rule_set.apply (c, lookup_context); 535 } 536 537 inline bool sanitize (hb_sanitize_context_t *c) { 538 TRACE_SANITIZE (); 539 return coverage.sanitize (c, this) 540 && classDef.sanitize (c, this) 541 && ruleSet.sanitize (c, this); 542 } 543 544 private: 545 USHORT format; /* Format identifier--format = 2 */ 546 OffsetTo<Coverage> 547 coverage; /* Offset to Coverage table--from 548 * beginning of table */ 549 OffsetTo<ClassDef> 550 classDef; /* Offset to glyph ClassDef table--from 551 * beginning of table */ 552 OffsetArrayOf<RuleSet> 553 ruleSet; /* Array of RuleSet tables 554 * ordered by class */ 555 public: 556 DEFINE_SIZE_ARRAY (8, ruleSet); 557}; 558 559 560struct ContextFormat3 561{ 562 friend struct Context; 563 564 private: 565 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 566 { 567 TRACE_APPLY (); 568 unsigned int index = (this+coverage[0]) (c->buffer->info[c->buffer->idx].codepoint); 569 if (likely (index == NOT_COVERED)) 570 return false; 571 572 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * glyphCount); 573 struct ContextLookupContext lookup_context = { 574 {match_coverage, apply_func}, 575 this 576 }; 577 return context_lookup (c, 578 glyphCount, (const USHORT *) (coverage + 1), 579 lookupCount, lookupRecord, 580 lookup_context); 581 } 582 583 inline bool sanitize (hb_sanitize_context_t *c) { 584 TRACE_SANITIZE (); 585 if (!c->check_struct (this)) return false; 586 unsigned int count = glyphCount; 587 if (!c->check_array (coverage, coverage[0].static_size, count)) return false; 588 for (unsigned int i = 0; i < count; i++) 589 if (!coverage[i].sanitize (c, this)) return false; 590 LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * count); 591 return c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount); 592 } 593 594 private: 595 USHORT format; /* Format identifier--format = 3 */ 596 USHORT glyphCount; /* Number of glyphs in the input glyph 597 * sequence */ 598 USHORT lookupCount; /* Number of LookupRecords */ 599 OffsetTo<Coverage> 600 coverage[VAR]; /* Array of offsets to Coverage 601 * table in glyph sequence order */ 602 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in 603 * design order */ 604 public: 605 DEFINE_SIZE_ARRAY2 (6, coverage, lookupRecordX); 606}; 607 608struct Context 609{ 610 protected: 611 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 612 { 613 TRACE_APPLY (); 614 switch (u.format) { 615 case 1: return u.format1.apply (c, apply_func); 616 case 2: return u.format2.apply (c, apply_func); 617 case 3: return u.format3.apply (c, apply_func); 618 default:return false; 619 } 620 } 621 622 inline bool sanitize (hb_sanitize_context_t *c) { 623 TRACE_SANITIZE (); 624 if (!u.format.sanitize (c)) return false; 625 switch (u.format) { 626 case 1: return u.format1.sanitize (c); 627 case 2: return u.format2.sanitize (c); 628 case 3: return u.format3.sanitize (c); 629 default:return true; 630 } 631 } 632 633 private: 634 union { 635 USHORT format; /* Format identifier */ 636 ContextFormat1 format1; 637 ContextFormat2 format2; 638 ContextFormat3 format3; 639 } u; 640}; 641 642 643/* Chaining Contextual lookups */ 644 645struct ChainContextLookupContext 646{ 647 ContextFuncs funcs; 648 const void *match_data[3]; 649}; 650 651static inline bool chain_context_lookup (hb_apply_context_t *c, 652 unsigned int backtrackCount, 653 const USHORT backtrack[], 654 unsigned int inputCount, /* Including the first glyph (not matched) */ 655 const USHORT input[], /* Array of input values--start with second glyph */ 656 unsigned int lookaheadCount, 657 const USHORT lookahead[], 658 unsigned int lookupCount, 659 const LookupRecord lookupRecord[], 660 ChainContextLookupContext &lookup_context) 661{ 662 /* First guess */ 663 if (unlikely (c->buffer->backtrack_len () < backtrackCount || 664 c->buffer->idx + inputCount + lookaheadCount > c->buffer->len || 665 inputCount + lookaheadCount > c->context_length)) 666 return false; 667 668 hb_apply_context_t new_context = *c; 669 return match_backtrack (c, 670 backtrackCount, backtrack, 671 lookup_context.funcs.match, lookup_context.match_data[0]) 672 && match_input (c, 673 inputCount, input, 674 lookup_context.funcs.match, lookup_context.match_data[1], 675 &new_context.context_length) 676 && match_lookahead (c, 677 lookaheadCount, lookahead, 678 lookup_context.funcs.match, lookup_context.match_data[2], 679 new_context.context_length) 680 && apply_lookup (&new_context, 681 inputCount, 682 lookupCount, lookupRecord, 683 lookup_context.funcs.apply); 684} 685 686struct ChainRule 687{ 688 friend struct ChainRuleSet; 689 690 private: 691 inline bool apply (hb_apply_context_t *c, ChainContextLookupContext &lookup_context) const 692 { 693 TRACE_APPLY (); 694 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack); 695 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input); 696 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 697 return chain_context_lookup (c, 698 backtrack.len, backtrack.array, 699 input.len, input.array, 700 lookahead.len, lookahead.array, 701 lookup.len, lookup.array, 702 lookup_context); 703 } 704 705 public: 706 inline bool sanitize (hb_sanitize_context_t *c) { 707 TRACE_SANITIZE (); 708 if (!backtrack.sanitize (c)) return false; 709 HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack); 710 if (!input.sanitize (c)) return false; 711 ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input); 712 if (!lookahead.sanitize (c)) return false; 713 ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 714 return lookup.sanitize (c); 715 } 716 717 private: 718 ArrayOf<USHORT> 719 backtrack; /* Array of backtracking values 720 * (to be matched before the input 721 * sequence) */ 722 HeadlessArrayOf<USHORT> 723 inputX; /* Array of input values (start with 724 * second glyph) */ 725 ArrayOf<USHORT> 726 lookaheadX; /* Array of lookahead values's (to be 727 * matched after the input sequence) */ 728 ArrayOf<LookupRecord> 729 lookupX; /* Array of LookupRecords--in 730 * design order) */ 731 public: 732 DEFINE_SIZE_MIN (8); 733}; 734 735struct ChainRuleSet 736{ 737 inline bool apply (hb_apply_context_t *c, ChainContextLookupContext &lookup_context) const 738 { 739 TRACE_APPLY (); 740 unsigned int num_rules = rule.len; 741 for (unsigned int i = 0; i < num_rules; i++) 742 { 743 if ((this+rule[i]).apply (c, lookup_context)) 744 return true; 745 } 746 747 return false; 748 } 749 750 inline bool sanitize (hb_sanitize_context_t *c) { 751 TRACE_SANITIZE (); 752 return rule.sanitize (c, this); 753 } 754 755 private: 756 OffsetArrayOf<ChainRule> 757 rule; /* Array of ChainRule tables 758 * ordered by preference */ 759 public: 760 DEFINE_SIZE_ARRAY (2, rule); 761}; 762 763struct ChainContextFormat1 764{ 765 friend struct ChainContext; 766 767 private: 768 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 769 { 770 TRACE_APPLY (); 771 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->idx].codepoint); 772 if (likely (index == NOT_COVERED)) 773 return false; 774 775 const ChainRuleSet &rule_set = this+ruleSet[index]; 776 struct ChainContextLookupContext lookup_context = { 777 {match_glyph, apply_func}, 778 {NULL, NULL, NULL} 779 }; 780 return rule_set.apply (c, lookup_context); 781 } 782 783 inline bool sanitize (hb_sanitize_context_t *c) { 784 TRACE_SANITIZE (); 785 return coverage.sanitize (c, this) 786 && ruleSet.sanitize (c, this); 787 } 788 789 private: 790 USHORT format; /* Format identifier--format = 1 */ 791 OffsetTo<Coverage> 792 coverage; /* Offset to Coverage table--from 793 * beginning of table */ 794 OffsetArrayOf<ChainRuleSet> 795 ruleSet; /* Array of ChainRuleSet tables 796 * ordered by Coverage Index */ 797 public: 798 DEFINE_SIZE_ARRAY (6, ruleSet); 799}; 800 801struct ChainContextFormat2 802{ 803 friend struct ChainContext; 804 805 private: 806 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 807 { 808 TRACE_APPLY (); 809 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->idx].codepoint); 810 if (likely (index == NOT_COVERED)) 811 return false; 812 813 const ClassDef &backtrack_class_def = this+backtrackClassDef; 814 const ClassDef &input_class_def = this+inputClassDef; 815 const ClassDef &lookahead_class_def = this+lookaheadClassDef; 816 817 index = input_class_def (c->buffer->info[c->buffer->idx].codepoint); 818 const ChainRuleSet &rule_set = this+ruleSet[index]; 819 struct ChainContextLookupContext lookup_context = { 820 {match_class, apply_func}, 821 {&backtrack_class_def, 822 &input_class_def, 823 &lookahead_class_def} 824 }; 825 return rule_set.apply (c, lookup_context); 826 } 827 828 inline bool sanitize (hb_sanitize_context_t *c) { 829 TRACE_SANITIZE (); 830 return coverage.sanitize (c, this) 831 && backtrackClassDef.sanitize (c, this) 832 && inputClassDef.sanitize (c, this) 833 && lookaheadClassDef.sanitize (c, this) 834 && ruleSet.sanitize (c, this); 835 } 836 837 private: 838 USHORT format; /* Format identifier--format = 2 */ 839 OffsetTo<Coverage> 840 coverage; /* Offset to Coverage table--from 841 * beginning of table */ 842 OffsetTo<ClassDef> 843 backtrackClassDef; /* Offset to glyph ClassDef table 844 * containing backtrack sequence 845 * data--from beginning of table */ 846 OffsetTo<ClassDef> 847 inputClassDef; /* Offset to glyph ClassDef 848 * table containing input sequence 849 * data--from beginning of table */ 850 OffsetTo<ClassDef> 851 lookaheadClassDef; /* Offset to glyph ClassDef table 852 * containing lookahead sequence 853 * data--from beginning of table */ 854 OffsetArrayOf<ChainRuleSet> 855 ruleSet; /* Array of ChainRuleSet tables 856 * ordered by class */ 857 public: 858 DEFINE_SIZE_ARRAY (12, ruleSet); 859}; 860 861struct ChainContextFormat3 862{ 863 friend struct ChainContext; 864 865 private: 866 867 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 868 { 869 TRACE_APPLY (); 870 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); 871 872 unsigned int index = (this+input[0]) (c->buffer->info[c->buffer->idx].codepoint); 873 if (likely (index == NOT_COVERED)) 874 return false; 875 876 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); 877 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 878 struct ChainContextLookupContext lookup_context = { 879 {match_coverage, apply_func}, 880 {this, this, this} 881 }; 882 return chain_context_lookup (c, 883 backtrack.len, (const USHORT *) backtrack.array, 884 input.len, (const USHORT *) input.array + 1, 885 lookahead.len, (const USHORT *) lookahead.array, 886 lookup.len, lookup.array, 887 lookup_context); 888 } 889 890 inline bool sanitize (hb_sanitize_context_t *c) { 891 TRACE_SANITIZE (); 892 if (!backtrack.sanitize (c, this)) return false; 893 OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); 894 if (!input.sanitize (c, this)) return false; 895 OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); 896 if (!lookahead.sanitize (c, this)) return false; 897 ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 898 return lookup.sanitize (c); 899 } 900 901 private: 902 USHORT format; /* Format identifier--format = 3 */ 903 OffsetArrayOf<Coverage> 904 backtrack; /* Array of coverage tables 905 * in backtracking sequence, in glyph 906 * sequence order */ 907 OffsetArrayOf<Coverage> 908 inputX ; /* Array of coverage 909 * tables in input sequence, in glyph 910 * sequence order */ 911 OffsetArrayOf<Coverage> 912 lookaheadX; /* Array of coverage tables 913 * in lookahead sequence, in glyph 914 * sequence order */ 915 ArrayOf<LookupRecord> 916 lookupX; /* Array of LookupRecords--in 917 * design order) */ 918 public: 919 DEFINE_SIZE_MIN (10); 920}; 921 922struct ChainContext 923{ 924 protected: 925 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 926 { 927 TRACE_APPLY (); 928 switch (u.format) { 929 case 1: return u.format1.apply (c, apply_func); 930 case 2: return u.format2.apply (c, apply_func); 931 case 3: return u.format3.apply (c, apply_func); 932 default:return false; 933 } 934 } 935 936 inline bool sanitize (hb_sanitize_context_t *c) { 937 TRACE_SANITIZE (); 938 if (!u.format.sanitize (c)) return false; 939 switch (u.format) { 940 case 1: return u.format1.sanitize (c); 941 case 2: return u.format2.sanitize (c); 942 case 3: return u.format3.sanitize (c); 943 default:return true; 944 } 945 } 946 947 private: 948 union { 949 USHORT format; /* Format identifier */ 950 ChainContextFormat1 format1; 951 ChainContextFormat2 format2; 952 ChainContextFormat3 format3; 953 } u; 954}; 955 956 957struct ExtensionFormat1 958{ 959 friend struct Extension; 960 961 protected: 962 inline unsigned int get_type (void) const { return extensionLookupType; } 963 inline unsigned int get_offset (void) const { return extensionOffset; } 964 965 inline bool sanitize (hb_sanitize_context_t *c) { 966 TRACE_SANITIZE (); 967 return c->check_struct (this); 968 } 969 970 private: 971 USHORT format; /* Format identifier. Set to 1. */ 972 USHORT extensionLookupType; /* Lookup type of subtable referenced 973 * by ExtensionOffset (i.e. the 974 * extension subtable). */ 975 ULONG extensionOffset; /* Offset to the extension subtable, 976 * of lookup type subtable. */ 977 public: 978 DEFINE_SIZE_STATIC (8); 979}; 980 981struct Extension 982{ 983 inline unsigned int get_type (void) const 984 { 985 switch (u.format) { 986 case 1: return u.format1.get_type (); 987 default:return 0; 988 } 989 } 990 inline unsigned int get_offset (void) const 991 { 992 switch (u.format) { 993 case 1: return u.format1.get_offset (); 994 default:return 0; 995 } 996 } 997 998 inline bool sanitize (hb_sanitize_context_t *c) { 999 TRACE_SANITIZE (); 1000 if (!u.format.sanitize (c)) return false; 1001 switch (u.format) { 1002 case 1: return u.format1.sanitize (c); 1003 default:return true; 1004 } 1005 } 1006 1007 private: 1008 union { 1009 USHORT format; /* Format identifier */ 1010 ExtensionFormat1 format1; 1011 } u; 1012}; 1013 1014 1015/* 1016 * GSUB/GPOS Common 1017 */ 1018 1019struct GSUBGPOS 1020{ 1021 static const hb_tag_t GSUBTag = HB_OT_TAG_GSUB; 1022 static const hb_tag_t GPOSTag = HB_OT_TAG_GPOS; 1023 1024 inline unsigned int get_script_count (void) const 1025 { return (this+scriptList).len; } 1026 inline const Tag& get_script_tag (unsigned int i) const 1027 { return (this+scriptList).get_tag (i); } 1028 inline unsigned int get_script_tags (unsigned int start_offset, 1029 unsigned int *script_count /* IN/OUT */, 1030 hb_tag_t *script_tags /* OUT */) const 1031 { return (this+scriptList).get_tags (start_offset, script_count, script_tags); } 1032 inline const Script& get_script (unsigned int i) const 1033 { return (this+scriptList)[i]; } 1034 inline bool find_script_index (hb_tag_t tag, unsigned int *index) const 1035 { return (this+scriptList).find_index (tag, index); } 1036 1037 inline unsigned int get_feature_count (void) const 1038 { return (this+featureList).len; } 1039 inline const Tag& get_feature_tag (unsigned int i) const 1040 { return (this+featureList).get_tag (i); } 1041 inline unsigned int get_feature_tags (unsigned int start_offset, 1042 unsigned int *feature_count /* IN/OUT */, 1043 hb_tag_t *feature_tags /* OUT */) const 1044 { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); } 1045 inline const Feature& get_feature (unsigned int i) const 1046 { return (this+featureList)[i]; } 1047 inline bool find_feature_index (hb_tag_t tag, unsigned int *index) const 1048 { return (this+featureList).find_index (tag, index); } 1049 1050 inline unsigned int get_lookup_count (void) const 1051 { return (this+lookupList).len; } 1052 inline const Lookup& get_lookup (unsigned int i) const 1053 { return (this+lookupList)[i]; } 1054 1055 inline bool sanitize (hb_sanitize_context_t *c) { 1056 TRACE_SANITIZE (); 1057 return version.sanitize (c) && likely (version.major == 1) 1058 && scriptList.sanitize (c, this) 1059 && featureList.sanitize (c, this) 1060 && lookupList.sanitize (c, this); 1061 } 1062 1063 protected: 1064 FixedVersion version; /* Version of the GSUB/GPOS table--initially set 1065 * to 0x00010000 */ 1066 OffsetTo<ScriptList> 1067 scriptList; /* ScriptList table */ 1068 OffsetTo<FeatureList> 1069 featureList; /* FeatureList table */ 1070 OffsetTo<LookupList> 1071 lookupList; /* LookupList table */ 1072 public: 1073 DEFINE_SIZE_STATIC (10); 1074}; 1075 1076 1077 1078#endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */ 1079