hb-ot-layout-gsubgpos-private.hh revision 744970af4d884cc87ffa645804578fec8df674a9
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-private.hh" 34 35HB_BEGIN_DECLS 36 37 38/* buffer var allocations */ 39#define lig_id() var2.u16[0] /* unique ligature id */ 40#define lig_comp() var2.u16[1] /* component number in the ligature (0 = base) */ 41 42 43#ifndef HB_DEBUG_APPLY 44#define HB_DEBUG_APPLY (HB_DEBUG+0) 45#endif 46 47#define TRACE_APPLY() \ 48 hb_trace_t<HB_DEBUG_APPLY> trace (&c->debug_depth, "APPLY", HB_FUNC, this); \ 49 50 51HB_BEGIN_DECLS 52 53struct hb_apply_context_t 54{ 55 unsigned int debug_depth; 56 hb_font_t *font; 57 hb_face_t *face; 58 hb_buffer_t *buffer; 59 hb_direction_t direction; 60 hb_mask_t lookup_mask; 61 unsigned int context_length; 62 unsigned int nesting_level_left; 63 unsigned int lookup_props; 64 unsigned int property; /* propety of first glyph */ 65 66 67 inline void replace_glyph (hb_codepoint_t glyph_index) const 68 { 69 clear_property (); 70 buffer->replace_glyph (glyph_index); 71 } 72 inline void replace_glyphs_be16 (unsigned int num_in, 73 unsigned int num_out, 74 const uint16_t *glyph_data_be) const 75 { 76 clear_property (); 77 buffer->replace_glyphs_be16 (num_in, num_out, glyph_data_be); 78 } 79 80 inline void guess_glyph_class (unsigned int klass) 81 { 82 /* XXX if ! has gdef */ 83 buffer->info[buffer->i].props_cache() = klass; 84 } 85 86 private: 87 inline void clear_property (void) const 88 { 89 /* XXX if has gdef */ 90 buffer->info[buffer->i].props_cache() = 0; 91 } 92}; 93 94 95 96typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data); 97typedef bool (*apply_lookup_func_t) (hb_apply_context_t *c, unsigned int lookup_index); 98 99struct ContextFuncs 100{ 101 match_func_t match; 102 apply_lookup_func_t apply; 103}; 104 105 106static inline bool match_glyph (hb_codepoint_t glyph_id, const USHORT &value, const void *data HB_UNUSED) 107{ 108 return glyph_id == value; 109} 110 111static inline bool match_class (hb_codepoint_t glyph_id, const USHORT &value, const void *data) 112{ 113 const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data); 114 return class_def.get_class (glyph_id) == value; 115} 116 117static inline bool match_coverage (hb_codepoint_t glyph_id, const USHORT &value, const void *data) 118{ 119 const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value; 120 return (data+coverage) (glyph_id) != NOT_COVERED; 121} 122 123 124static inline bool match_input (hb_apply_context_t *c, 125 unsigned int count, /* Including the first glyph (not matched) */ 126 const USHORT input[], /* Array of input values--start with second glyph */ 127 match_func_t match_func, 128 const void *match_data, 129 unsigned int *context_length_out) 130{ 131 unsigned int i, j; 132 unsigned int end = MIN (c->buffer->len, c->buffer->i + c->context_length); 133 if (unlikely (c->buffer->i + count > end)) 134 return false; 135 136 for (i = 1, j = c->buffer->i + 1; i < count; i++, j++) 137 { 138 while (_hb_ot_layout_skip_mark (c->face, &c->buffer->info[j], c->lookup_props, NULL)) 139 { 140 if (unlikely (j + count - i == end)) 141 return false; 142 j++; 143 } 144 145 if (likely (!match_func (c->buffer->info[j].codepoint, input[i - 1], match_data))) 146 return false; 147 } 148 149 *context_length_out = j - c->buffer->i; 150 151 return true; 152} 153 154static inline bool match_backtrack (hb_apply_context_t *c, 155 unsigned int count, 156 const USHORT backtrack[], 157 match_func_t match_func, 158 const void *match_data) 159{ 160 if (unlikely (c->buffer->backtrack_len () < count)) 161 return false; 162 163 for (unsigned int i = 0, j = c->buffer->backtrack_len () - 1; i < count; i++, j--) 164 { 165 while (_hb_ot_layout_skip_mark (c->face, &c->buffer->out_info[j], c->lookup_props, NULL)) 166 { 167 if (unlikely (j + 1 == count - i)) 168 return false; 169 j--; 170 } 171 172 if (likely (!match_func (c->buffer->out_info[j].codepoint, backtrack[i], match_data))) 173 return false; 174 } 175 176 return true; 177} 178 179static inline bool match_lookahead (hb_apply_context_t *c, 180 unsigned int count, 181 const USHORT lookahead[], 182 match_func_t match_func, 183 const void *match_data, 184 unsigned int offset) 185{ 186 unsigned int i, j; 187 unsigned int end = MIN (c->buffer->len, c->buffer->i + c->context_length); 188 if (unlikely (c->buffer->i + offset + count > end)) 189 return false; 190 191 for (i = 0, j = c->buffer->i + offset; i < count; i++, j++) 192 { 193 while (_hb_ot_layout_skip_mark (c->face, &c->buffer->info[j], c->lookup_props, NULL)) 194 { 195 if (unlikely (j + count - i == end)) 196 return false; 197 j++; 198 } 199 200 if (likely (!match_func (c->buffer->info[j].codepoint, lookahead[i], match_data))) 201 return false; 202 } 203 204 return true; 205} 206 207HB_END_DECLS 208 209 210struct LookupRecord 211{ 212 inline bool sanitize (hb_sanitize_context_t *c) { 213 TRACE_SANITIZE (); 214 return c->check_struct (this); 215 } 216 217 USHORT sequenceIndex; /* Index into current glyph 218 * sequence--first glyph = 0 */ 219 USHORT lookupListIndex; /* Lookup to apply to that 220 * position--zero--based */ 221 public: 222 DEFINE_SIZE_STATIC (4); 223}; 224 225 226HB_BEGIN_DECLS 227 228static inline bool apply_lookup (hb_apply_context_t *c, 229 unsigned int count, /* Including the first glyph */ 230 unsigned int lookupCount, 231 const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */ 232 apply_lookup_func_t apply_func) 233{ 234 unsigned int end = MIN (c->buffer->len, c->buffer->i + c->context_length); 235 if (unlikely (count == 0 || c->buffer->i + count > end)) 236 return false; 237 238 /* TODO We don't support lookupRecord arrays that are not increasing: 239 * Should be easy for in_place ones at least. */ 240 241 /* Note: If sublookup is reverse, it will underflow after the first loop 242 * and we jump out of it. Not entirely disastrous. So we don't check 243 * for reverse lookup here. 244 */ 245 for (unsigned int i = 0; i < count; /* NOP */) 246 { 247 while (_hb_ot_layout_skip_mark (c->face, &c->buffer->info[c->buffer->i], c->lookup_props, NULL)) 248 { 249 if (unlikely (c->buffer->i == end)) 250 return true; 251 /* No lookup applied for this index */ 252 c->buffer->next_glyph (); 253 } 254 255 if (lookupCount && i == lookupRecord->sequenceIndex) 256 { 257 unsigned int old_pos = c->buffer->i; 258 259 /* Apply a lookup */ 260 bool done = apply_func (c, lookupRecord->lookupListIndex); 261 262 lookupRecord++; 263 lookupCount--; 264 /* Err, this is wrong if the lookup jumped over some glyphs */ 265 i += c->buffer->i - old_pos; 266 if (unlikely (c->buffer->i == end)) 267 return true; 268 269 if (!done) 270 goto not_applied; 271 } 272 else 273 { 274 not_applied: 275 /* No lookup applied for this index */ 276 c->buffer->next_glyph (); 277 i++; 278 } 279 } 280 281 return true; 282} 283 284HB_END_DECLS 285 286 287/* Contextual lookups */ 288 289struct ContextLookupContext 290{ 291 ContextFuncs funcs; 292 const void *match_data; 293}; 294 295static inline bool context_lookup (hb_apply_context_t *c, 296 unsigned int inputCount, /* Including the first glyph (not matched) */ 297 const USHORT input[], /* Array of input values--start with second glyph */ 298 unsigned int lookupCount, 299 const LookupRecord lookupRecord[], 300 ContextLookupContext &lookup_context) 301{ 302 hb_apply_context_t new_context = *c; 303 return match_input (c, 304 inputCount, input, 305 lookup_context.funcs.match, lookup_context.match_data, 306 &new_context.context_length) 307 && apply_lookup (&new_context, 308 inputCount, 309 lookupCount, lookupRecord, 310 lookup_context.funcs.apply); 311} 312 313struct Rule 314{ 315 friend struct RuleSet; 316 317 private: 318 inline bool apply (hb_apply_context_t *c, ContextLookupContext &lookup_context) const 319 { 320 TRACE_APPLY (); 321 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (input, input[0].static_size * (inputCount ? inputCount - 1 : 0)); 322 return context_lookup (c, 323 inputCount, input, 324 lookupCount, lookupRecord, 325 lookup_context); 326 } 327 328 public: 329 inline bool sanitize (hb_sanitize_context_t *c) { 330 TRACE_SANITIZE (); 331 return inputCount.sanitize (c) 332 && lookupCount.sanitize (c) 333 && c->check_range (input, 334 input[0].static_size * inputCount 335 + lookupRecordX[0].static_size * lookupCount); 336 } 337 338 private: 339 USHORT inputCount; /* Total number of glyphs in input 340 * glyph sequence--includes the first 341 * glyph */ 342 USHORT lookupCount; /* Number of LookupRecords */ 343 USHORT input[VAR]; /* Array of match inputs--start with 344 * second glyph */ 345 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in 346 * design order */ 347 public: 348 DEFINE_SIZE_ARRAY2 (4, input, lookupRecordX); 349}; 350 351struct RuleSet 352{ 353 inline bool apply (hb_apply_context_t *c, ContextLookupContext &lookup_context) const 354 { 355 TRACE_APPLY (); 356 unsigned int num_rules = rule.len; 357 for (unsigned int i = 0; i < num_rules; i++) 358 { 359 if ((this+rule[i]).apply (c, lookup_context)) 360 return true; 361 } 362 363 return false; 364 } 365 366 inline bool sanitize (hb_sanitize_context_t *c) { 367 TRACE_SANITIZE (); 368 return rule.sanitize (c, this); 369 } 370 371 private: 372 OffsetArrayOf<Rule> 373 rule; /* Array of Rule tables 374 * ordered by preference */ 375 public: 376 DEFINE_SIZE_ARRAY (2, rule); 377}; 378 379 380struct ContextFormat1 381{ 382 friend struct Context; 383 384 private: 385 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 386 { 387 TRACE_APPLY (); 388 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->i].codepoint); 389 if (likely (index == NOT_COVERED)) 390 return false; 391 392 const RuleSet &rule_set = this+ruleSet[index]; 393 struct ContextLookupContext lookup_context = { 394 {match_glyph, apply_func}, 395 NULL 396 }; 397 return rule_set.apply (c, lookup_context); 398 } 399 400 inline bool sanitize (hb_sanitize_context_t *c) { 401 TRACE_SANITIZE (); 402 return coverage.sanitize (c, this) 403 && ruleSet.sanitize (c, this); 404 } 405 406 private: 407 USHORT format; /* Format identifier--format = 1 */ 408 OffsetTo<Coverage> 409 coverage; /* Offset to Coverage table--from 410 * beginning of table */ 411 OffsetArrayOf<RuleSet> 412 ruleSet; /* Array of RuleSet tables 413 * ordered by Coverage Index */ 414 public: 415 DEFINE_SIZE_ARRAY (6, ruleSet); 416}; 417 418 419struct ContextFormat2 420{ 421 friend struct Context; 422 423 private: 424 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 425 { 426 TRACE_APPLY (); 427 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->i].codepoint); 428 if (likely (index == NOT_COVERED)) 429 return false; 430 431 const ClassDef &class_def = this+classDef; 432 index = class_def (c->buffer->info[c->buffer->i].codepoint); 433 const RuleSet &rule_set = this+ruleSet[index]; 434 struct ContextLookupContext lookup_context = { 435 {match_class, apply_func}, 436 &class_def 437 }; 438 return rule_set.apply (c, lookup_context); 439 } 440 441 inline bool sanitize (hb_sanitize_context_t *c) { 442 TRACE_SANITIZE (); 443 return coverage.sanitize (c, this) 444 && classDef.sanitize (c, this) 445 && ruleSet.sanitize (c, this); 446 } 447 448 private: 449 USHORT format; /* Format identifier--format = 2 */ 450 OffsetTo<Coverage> 451 coverage; /* Offset to Coverage table--from 452 * beginning of table */ 453 OffsetTo<ClassDef> 454 classDef; /* Offset to glyph ClassDef table--from 455 * beginning of table */ 456 OffsetArrayOf<RuleSet> 457 ruleSet; /* Array of RuleSet tables 458 * ordered by class */ 459 public: 460 DEFINE_SIZE_ARRAY (8, ruleSet); 461}; 462 463 464struct ContextFormat3 465{ 466 friend struct Context; 467 468 private: 469 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 470 { 471 TRACE_APPLY (); 472 unsigned int index = (this+coverage[0]) (c->buffer->info[c->buffer->i].codepoint); 473 if (likely (index == NOT_COVERED)) 474 return false; 475 476 const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * glyphCount); 477 struct ContextLookupContext lookup_context = { 478 {match_coverage, apply_func}, 479 this 480 }; 481 return context_lookup (c, 482 glyphCount, (const USHORT *) (coverage + 1), 483 lookupCount, lookupRecord, 484 lookup_context); 485 } 486 487 inline bool sanitize (hb_sanitize_context_t *c) { 488 TRACE_SANITIZE (); 489 if (!c->check_struct (this)) return false; 490 unsigned int count = glyphCount; 491 if (!c->check_array (coverage, coverage[0].static_size, count)) return false; 492 for (unsigned int i = 0; i < count; i++) 493 if (!coverage[i].sanitize (c, this)) return false; 494 LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * count); 495 return c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount); 496 } 497 498 private: 499 USHORT format; /* Format identifier--format = 3 */ 500 USHORT glyphCount; /* Number of glyphs in the input glyph 501 * sequence */ 502 USHORT lookupCount; /* Number of LookupRecords */ 503 OffsetTo<Coverage> 504 coverage[VAR]; /* Array of offsets to Coverage 505 * table in glyph sequence order */ 506 LookupRecord lookupRecordX[VAR]; /* Array of LookupRecords--in 507 * design order */ 508 public: 509 DEFINE_SIZE_ARRAY2 (6, coverage, lookupRecordX); 510}; 511 512struct Context 513{ 514 protected: 515 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 516 { 517 TRACE_APPLY (); 518 switch (u.format) { 519 case 1: return u.format1.apply (c, apply_func); 520 case 2: return u.format2.apply (c, apply_func); 521 case 3: return u.format3.apply (c, apply_func); 522 default:return false; 523 } 524 } 525 526 inline bool sanitize (hb_sanitize_context_t *c) { 527 TRACE_SANITIZE (); 528 if (!u.format.sanitize (c)) return false; 529 switch (u.format) { 530 case 1: return u.format1.sanitize (c); 531 case 2: return u.format2.sanitize (c); 532 case 3: return u.format3.sanitize (c); 533 default:return true; 534 } 535 } 536 537 private: 538 union { 539 USHORT format; /* Format identifier */ 540 ContextFormat1 format1; 541 ContextFormat2 format2; 542 ContextFormat3 format3; 543 } u; 544}; 545 546 547/* Chaining Contextual lookups */ 548 549struct ChainContextLookupContext 550{ 551 ContextFuncs funcs; 552 const void *match_data[3]; 553}; 554 555static inline bool chain_context_lookup (hb_apply_context_t *c, 556 unsigned int backtrackCount, 557 const USHORT backtrack[], 558 unsigned int inputCount, /* Including the first glyph (not matched) */ 559 const USHORT input[], /* Array of input values--start with second glyph */ 560 unsigned int lookaheadCount, 561 const USHORT lookahead[], 562 unsigned int lookupCount, 563 const LookupRecord lookupRecord[], 564 ChainContextLookupContext &lookup_context) 565{ 566 /* First guess */ 567 if (unlikely (c->buffer->backtrack_len () < backtrackCount || 568 c->buffer->i + inputCount + lookaheadCount > c->buffer->len || 569 inputCount + lookaheadCount > c->context_length)) 570 return false; 571 572 hb_apply_context_t new_context = *c; 573 return match_backtrack (c, 574 backtrackCount, backtrack, 575 lookup_context.funcs.match, lookup_context.match_data[0]) 576 && match_input (c, 577 inputCount, input, 578 lookup_context.funcs.match, lookup_context.match_data[1], 579 &new_context.context_length) 580 && match_lookahead (c, 581 lookaheadCount, lookahead, 582 lookup_context.funcs.match, lookup_context.match_data[2], 583 new_context.context_length) 584 && apply_lookup (&new_context, 585 inputCount, 586 lookupCount, lookupRecord, 587 lookup_context.funcs.apply); 588} 589 590struct ChainRule 591{ 592 friend struct ChainRuleSet; 593 594 private: 595 inline bool apply (hb_apply_context_t *c, ChainContextLookupContext &lookup_context) const 596 { 597 TRACE_APPLY (); 598 const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack); 599 const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input); 600 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 601 return chain_context_lookup (c, 602 backtrack.len, backtrack.array, 603 input.len, input.array, 604 lookahead.len, lookahead.array, 605 lookup.len, lookup.array, 606 lookup_context); 607 } 608 609 public: 610 inline bool sanitize (hb_sanitize_context_t *c) { 611 TRACE_SANITIZE (); 612 if (!backtrack.sanitize (c)) return false; 613 HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack); 614 if (!input.sanitize (c)) return false; 615 ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input); 616 if (!lookahead.sanitize (c)) return false; 617 ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 618 return lookup.sanitize (c); 619 } 620 621 private: 622 ArrayOf<USHORT> 623 backtrack; /* Array of backtracking values 624 * (to be matched before the input 625 * sequence) */ 626 HeadlessArrayOf<USHORT> 627 inputX; /* Array of input values (start with 628 * second glyph) */ 629 ArrayOf<USHORT> 630 lookaheadX; /* Array of lookahead values's (to be 631 * matched after the input sequence) */ 632 ArrayOf<LookupRecord> 633 lookupX; /* Array of LookupRecords--in 634 * design order) */ 635 public: 636 DEFINE_SIZE_MIN (8); 637}; 638 639struct ChainRuleSet 640{ 641 inline bool apply (hb_apply_context_t *c, ChainContextLookupContext &lookup_context) const 642 { 643 TRACE_APPLY (); 644 unsigned int num_rules = rule.len; 645 for (unsigned int i = 0; i < num_rules; i++) 646 { 647 if ((this+rule[i]).apply (c, lookup_context)) 648 return true; 649 } 650 651 return false; 652 } 653 654 inline bool sanitize (hb_sanitize_context_t *c) { 655 TRACE_SANITIZE (); 656 return rule.sanitize (c, this); 657 } 658 659 private: 660 OffsetArrayOf<ChainRule> 661 rule; /* Array of ChainRule tables 662 * ordered by preference */ 663 public: 664 DEFINE_SIZE_ARRAY (2, rule); 665}; 666 667struct ChainContextFormat1 668{ 669 friend struct ChainContext; 670 671 private: 672 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 673 { 674 TRACE_APPLY (); 675 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->i].codepoint); 676 if (likely (index == NOT_COVERED)) 677 return false; 678 679 const ChainRuleSet &rule_set = this+ruleSet[index]; 680 struct ChainContextLookupContext lookup_context = { 681 {match_glyph, apply_func}, 682 {NULL, NULL, NULL} 683 }; 684 return rule_set.apply (c, lookup_context); 685 } 686 687 inline bool sanitize (hb_sanitize_context_t *c) { 688 TRACE_SANITIZE (); 689 return coverage.sanitize (c, this) 690 && ruleSet.sanitize (c, this); 691 } 692 693 private: 694 USHORT format; /* Format identifier--format = 1 */ 695 OffsetTo<Coverage> 696 coverage; /* Offset to Coverage table--from 697 * beginning of table */ 698 OffsetArrayOf<ChainRuleSet> 699 ruleSet; /* Array of ChainRuleSet tables 700 * ordered by Coverage Index */ 701 public: 702 DEFINE_SIZE_ARRAY (6, ruleSet); 703}; 704 705struct ChainContextFormat2 706{ 707 friend struct ChainContext; 708 709 private: 710 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 711 { 712 TRACE_APPLY (); 713 unsigned int index = (this+coverage) (c->buffer->info[c->buffer->i].codepoint); 714 if (likely (index == NOT_COVERED)) 715 return false; 716 717 const ClassDef &backtrack_class_def = this+backtrackClassDef; 718 const ClassDef &input_class_def = this+inputClassDef; 719 const ClassDef &lookahead_class_def = this+lookaheadClassDef; 720 721 index = input_class_def (c->buffer->info[c->buffer->i].codepoint); 722 const ChainRuleSet &rule_set = this+ruleSet[index]; 723 struct ChainContextLookupContext lookup_context = { 724 {match_class, apply_func}, 725 {&backtrack_class_def, 726 &input_class_def, 727 &lookahead_class_def} 728 }; 729 return rule_set.apply (c, lookup_context); 730 } 731 732 inline bool sanitize (hb_sanitize_context_t *c) { 733 TRACE_SANITIZE (); 734 return coverage.sanitize (c, this) 735 && backtrackClassDef.sanitize (c, this) 736 && inputClassDef.sanitize (c, this) 737 && lookaheadClassDef.sanitize (c, this) 738 && ruleSet.sanitize (c, this); 739 } 740 741 private: 742 USHORT format; /* Format identifier--format = 2 */ 743 OffsetTo<Coverage> 744 coverage; /* Offset to Coverage table--from 745 * beginning of table */ 746 OffsetTo<ClassDef> 747 backtrackClassDef; /* Offset to glyph ClassDef table 748 * containing backtrack sequence 749 * data--from beginning of table */ 750 OffsetTo<ClassDef> 751 inputClassDef; /* Offset to glyph ClassDef 752 * table containing input sequence 753 * data--from beginning of table */ 754 OffsetTo<ClassDef> 755 lookaheadClassDef; /* Offset to glyph ClassDef table 756 * containing lookahead sequence 757 * data--from beginning of table */ 758 OffsetArrayOf<ChainRuleSet> 759 ruleSet; /* Array of ChainRuleSet tables 760 * ordered by class */ 761 public: 762 DEFINE_SIZE_ARRAY (12, ruleSet); 763}; 764 765struct ChainContextFormat3 766{ 767 friend struct ChainContext; 768 769 private: 770 771 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 772 { 773 TRACE_APPLY (); 774 const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); 775 776 unsigned int index = (this+input[0]) (c->buffer->info[c->buffer->i].codepoint); 777 if (likely (index == NOT_COVERED)) 778 return false; 779 780 const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); 781 const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 782 struct ChainContextLookupContext lookup_context = { 783 {match_coverage, apply_func}, 784 {this, this, this} 785 }; 786 return chain_context_lookup (c, 787 backtrack.len, (const USHORT *) backtrack.array, 788 input.len, (const USHORT *) input.array + 1, 789 lookahead.len, (const USHORT *) lookahead.array, 790 lookup.len, lookup.array, 791 lookup_context); 792 } 793 794 inline bool sanitize (hb_sanitize_context_t *c) { 795 TRACE_SANITIZE (); 796 if (!backtrack.sanitize (c, this)) return false; 797 OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack); 798 if (!input.sanitize (c, this)) return false; 799 OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input); 800 if (!lookahead.sanitize (c, this)) return false; 801 ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead); 802 return lookup.sanitize (c); 803 } 804 805 private: 806 USHORT format; /* Format identifier--format = 3 */ 807 OffsetArrayOf<Coverage> 808 backtrack; /* Array of coverage tables 809 * in backtracking sequence, in glyph 810 * sequence order */ 811 OffsetArrayOf<Coverage> 812 inputX ; /* Array of coverage 813 * tables in input sequence, in glyph 814 * sequence order */ 815 OffsetArrayOf<Coverage> 816 lookaheadX; /* Array of coverage tables 817 * in lookahead sequence, in glyph 818 * sequence order */ 819 ArrayOf<LookupRecord> 820 lookupX; /* Array of LookupRecords--in 821 * design order) */ 822 public: 823 DEFINE_SIZE_MIN (10); 824}; 825 826struct ChainContext 827{ 828 protected: 829 inline bool apply (hb_apply_context_t *c, apply_lookup_func_t apply_func) const 830 { 831 TRACE_APPLY (); 832 switch (u.format) { 833 case 1: return u.format1.apply (c, apply_func); 834 case 2: return u.format2.apply (c, apply_func); 835 case 3: return u.format3.apply (c, apply_func); 836 default:return false; 837 } 838 } 839 840 inline bool sanitize (hb_sanitize_context_t *c) { 841 TRACE_SANITIZE (); 842 if (!u.format.sanitize (c)) return false; 843 switch (u.format) { 844 case 1: return u.format1.sanitize (c); 845 case 2: return u.format2.sanitize (c); 846 case 3: return u.format3.sanitize (c); 847 default:return true; 848 } 849 } 850 851 private: 852 union { 853 USHORT format; /* Format identifier */ 854 ChainContextFormat1 format1; 855 ChainContextFormat2 format2; 856 ChainContextFormat3 format3; 857 } u; 858}; 859 860 861struct ExtensionFormat1 862{ 863 friend struct Extension; 864 865 protected: 866 inline unsigned int get_type (void) const { return extensionLookupType; } 867 inline unsigned int get_offset (void) const { return extensionOffset; } 868 869 inline bool sanitize (hb_sanitize_context_t *c) { 870 TRACE_SANITIZE (); 871 return c->check_struct (this); 872 } 873 874 private: 875 USHORT format; /* Format identifier. Set to 1. */ 876 USHORT extensionLookupType; /* Lookup type of subtable referenced 877 * by ExtensionOffset (i.e. the 878 * extension subtable). */ 879 ULONG extensionOffset; /* Offset to the extension subtable, 880 * of lookup type subtable. */ 881 public: 882 DEFINE_SIZE_STATIC (8); 883}; 884 885struct Extension 886{ 887 inline unsigned int get_type (void) const 888 { 889 switch (u.format) { 890 case 1: return u.format1.get_type (); 891 default:return 0; 892 } 893 } 894 inline unsigned int get_offset (void) const 895 { 896 switch (u.format) { 897 case 1: return u.format1.get_offset (); 898 default:return 0; 899 } 900 } 901 902 inline bool sanitize (hb_sanitize_context_t *c) { 903 TRACE_SANITIZE (); 904 if (!u.format.sanitize (c)) return false; 905 switch (u.format) { 906 case 1: return u.format1.sanitize (c); 907 default:return true; 908 } 909 } 910 911 private: 912 union { 913 USHORT format; /* Format identifier */ 914 ExtensionFormat1 format1; 915 } u; 916}; 917 918 919/* 920 * GSUB/GPOS Common 921 */ 922 923struct GSUBGPOS 924{ 925 static const hb_tag_t GSUBTag = HB_OT_TAG_GSUB; 926 static const hb_tag_t GPOSTag = HB_OT_TAG_GPOS; 927 928 inline unsigned int get_script_count (void) const 929 { return (this+scriptList).len; } 930 inline const Tag& get_script_tag (unsigned int i) const 931 { return (this+scriptList).get_tag (i); } 932 inline unsigned int get_script_tags (unsigned int start_offset, 933 unsigned int *script_count /* IN/OUT */, 934 hb_tag_t *script_tags /* OUT */) const 935 { return (this+scriptList).get_tags (start_offset, script_count, script_tags); } 936 inline const Script& get_script (unsigned int i) const 937 { return (this+scriptList)[i]; } 938 inline bool find_script_index (hb_tag_t tag, unsigned int *index) const 939 { return (this+scriptList).find_index (tag, index); } 940 941 inline unsigned int get_feature_count (void) const 942 { return (this+featureList).len; } 943 inline const Tag& get_feature_tag (unsigned int i) const 944 { return (this+featureList).get_tag (i); } 945 inline unsigned int get_feature_tags (unsigned int start_offset, 946 unsigned int *feature_count /* IN/OUT */, 947 hb_tag_t *feature_tags /* OUT */) const 948 { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); } 949 inline const Feature& get_feature (unsigned int i) const 950 { return (this+featureList)[i]; } 951 inline bool find_feature_index (hb_tag_t tag, unsigned int *index) const 952 { return (this+featureList).find_index (tag, index); } 953 954 inline unsigned int get_lookup_count (void) const 955 { return (this+lookupList).len; } 956 inline const Lookup& get_lookup (unsigned int i) const 957 { return (this+lookupList)[i]; } 958 959 inline bool sanitize (hb_sanitize_context_t *c) { 960 TRACE_SANITIZE (); 961 return version.sanitize (c) && likely (version.major == 1) 962 && scriptList.sanitize (c, this) 963 && featureList.sanitize (c, this) 964 && lookupList.sanitize (c, this); 965 } 966 967 protected: 968 FixedVersion version; /* Version of the GSUB/GPOS table--initially set 969 * to 0x00010000 */ 970 OffsetTo<ScriptList> 971 scriptList; /* ScriptList table */ 972 OffsetTo<FeatureList> 973 featureList; /* FeatureList table */ 974 OffsetTo<LookupList> 975 lookupList; /* LookupList table */ 976 public: 977 DEFINE_SIZE_STATIC (10); 978}; 979 980 981HB_END_DECLS 982 983#endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */ 984