third_party/harfbuzz-ng/src/hb-ot-layout-gsub-table.hh

   1 /*
   2  * Copyright © 2007,2008,2009,2010  Red Hat, Inc.
   3  * Copyright © 2010,2012,2013  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_GSUB_TABLE_HH
  30 #define HB_OT_LAYOUT_GSUB_TABLE_HH
  31
  32 #include "hb-ot-layout-gsubgpos-private.hh"
  33
  34
  35 namespace OT {
  36
  37
  38 struct SingleSubstFormat1
  39 {
  40   inline void closure (hb_closure_context_t *c) const
  41   {
  42     TRACE_CLOSURE (this);
  43     Coverage::Iter iter;
  44     for (iter.init (this+coverage); iter.more (); iter.next ()) {
  45       hb_codepoint_t glyph_id = iter.get_glyph ();
  46       if (c->glyphs->has (glyph_id))
  47         c->glyphs->add ((glyph_id + deltaGlyphID) & 0xFFFF);
  48     }
  49   }
  50
  51   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
  52   {
  53     TRACE_COLLECT_GLYPHS (this);
  54     Coverage::Iter iter;
  55     for (iter.init (this+coverage); iter.more (); iter.next ()) {
  56       hb_codepoint_t glyph_id = iter.get_glyph ();
  57       c->input->add (glyph_id);
  58       c->output->add ((glyph_id + deltaGlyphID) & 0xFFFF);
  59     }
  60   }
  61
  62   inline const Coverage &get_coverage (void) const
  63   {
  64     return this+coverage;
  65   }
  66
  67   inline bool would_apply (hb_would_apply_context_t *c) const
  68   {
  69     TRACE_WOULD_APPLY (this);
  70     return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
  71   }
  72
  73   inline bool apply (hb_apply_context_t *c) const
  74   {
  75     TRACE_APPLY (this);
  76     hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
  77     unsigned int index = (this+coverage).get_coverage (glyph_id);
  78     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
  79
  80     /* According to the Adobe Annotated OpenType Suite, result is always
  81      * limited to 16bit. */
  82     glyph_id = (glyph_id + deltaGlyphID) & 0xFFFF;
  83     c->replace_glyph (glyph_id);
  84
  85     return TRACE_RETURN (true);
  86   }
  87
  88   inline bool serialize (hb_serialize_context_t *c,
  89                          Supplier<GlyphID> &glyphs,
  90                          unsigned int num_glyphs,
  91                          int delta)
  92   {
  93     TRACE_SERIALIZE (this);
  94     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
  95     if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
  96     deltaGlyphID.set (delta); /* TODO(serilaize) overflow? */
  97     return TRACE_RETURN (true);
  98   }
  99
 100   inline bool sanitize (hb_sanitize_context_t *c) {
 101     TRACE_SANITIZE (this);
 102     return TRACE_RETURN (coverage.sanitize (c, this) && deltaGlyphID.sanitize (c));
 103   }
 104
 105   protected:
 106   USHORT        format;                 /* Format identifier--format = 1 */
 107   OffsetTo<Coverage>
 108                 coverage;               /* Offset to Coverage table--from
 109                                          * beginning of Substitution table */
 110   SHORT         deltaGlyphID;           /* Add to original GlyphID to get
 111                                          * substitute GlyphID */
 112   public:
 113   DEFINE_SIZE_STATIC (6);
 114 };
 115
 116 struct SingleSubstFormat2
 117 {
 118   inline void closure (hb_closure_context_t *c) const
 119   {
 120     TRACE_CLOSURE (this);
 121     Coverage::Iter iter;
 122     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 123       if (c->glyphs->has (iter.get_glyph ()))
 124         c->glyphs->add (substitute[iter.get_coverage ()]);
 125     }
 126   }
 127
 128   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 129   {
 130     TRACE_COLLECT_GLYPHS (this);
 131     Coverage::Iter iter;
 132     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 133       c->input->add (iter.get_glyph ());
 134       c->output->add (substitute[iter.get_coverage ()]);
 135     }
 136   }
 137
 138   inline const Coverage &get_coverage (void) const
 139   {
 140     return this+coverage;
 141   }
 142
 143   inline bool would_apply (hb_would_apply_context_t *c) const
 144   {
 145     TRACE_WOULD_APPLY (this);
 146     return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
 147   }
 148
 149   inline bool apply (hb_apply_context_t *c) const
 150   {
 151     TRACE_APPLY (this);
 152     hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
 153     unsigned int index = (this+coverage).get_coverage (glyph_id);
 154     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 155
 156     if (unlikely (index >= substitute.len)) return TRACE_RETURN (false);
 157
 158     glyph_id = substitute[index];
 159     c->replace_glyph (glyph_id);
 160
 161     return TRACE_RETURN (true);
 162   }
 163
 164   inline bool serialize (hb_serialize_context_t *c,
 165                          Supplier<GlyphID> &glyphs,
 166                          Supplier<GlyphID> &substitutes,
 167                          unsigned int num_glyphs)
 168   {
 169     TRACE_SERIALIZE (this);
 170     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
 171     if (unlikely (!substitute.serialize (c, substitutes, num_glyphs))) return TRACE_RETURN (false);
 172     if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
 173     return TRACE_RETURN (true);
 174   }
 175
 176   inline bool sanitize (hb_sanitize_context_t *c) {
 177     TRACE_SANITIZE (this);
 178     return TRACE_RETURN (coverage.sanitize (c, this) && substitute.sanitize (c));
 179   }
 180
 181   protected:
 182   USHORT        format;                 /* Format identifier--format = 2 */
 183   OffsetTo<Coverage>
 184                 coverage;               /* Offset to Coverage table--from
 185                                          * beginning of Substitution table */
 186   ArrayOf<GlyphID>
 187                 substitute;             /* Array of substitute
 188                                          * GlyphIDs--ordered by Coverage Index */
 189   public:
 190   DEFINE_SIZE_ARRAY (6, substitute);
 191 };
 192
 193 struct SingleSubst
 194 {
 195   inline bool serialize (hb_serialize_context_t *c,
 196                          Supplier<GlyphID> &glyphs,
 197                          Supplier<GlyphID> &substitutes,
 198                          unsigned int num_glyphs)
 199   {
 200     TRACE_SERIALIZE (this);
 201     if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
 202     unsigned int format = 2;
 203     int delta;
 204     if (num_glyphs) {
 205       format = 1;
 206       /* TODO(serialize) check for wrap-around */
 207       delta = substitutes[0] - glyphs[0];
 208       for (unsigned int i = 1; i < num_glyphs; i++)
 209         if (delta != substitutes[i] - glyphs[i]) {
 210           format = 2;
 211           break;
 212         }
 213     }
 214     u.format.set (format);
 215     switch (u.format) {
 216     case 1: return TRACE_RETURN (u.format1.serialize (c, glyphs, num_glyphs, delta));
 217     case 2: return TRACE_RETURN (u.format2.serialize (c, glyphs, substitutes, num_glyphs));
 218     default:return TRACE_RETURN (false);
 219     }
 220   }
 221
 222   template <typename context_t>
 223   inline typename context_t::return_t dispatch (context_t *c) const
 224   {
 225     TRACE_DISPATCH (this);
 226     switch (u.format) {
 227     case 1: return TRACE_RETURN (c->dispatch (u.format1));
 228     case 2: return TRACE_RETURN (c->dispatch (u.format2));
 229     default:return TRACE_RETURN (c->default_return_value ());
 230     }
 231   }
 232
 233   inline bool sanitize (hb_sanitize_context_t *c) {
 234     TRACE_SANITIZE (this);
 235     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
 236     switch (u.format) {
 237     case 1: return TRACE_RETURN (u.format1.sanitize (c));
 238     case 2: return TRACE_RETURN (u.format2.sanitize (c));
 239     default:return TRACE_RETURN (true);
 240     }
 241   }
 242
 243   protected:
 244   union {
 245   USHORT                format;         /* Format identifier */
 246   SingleSubstFormat1    format1;
 247   SingleSubstFormat2    format2;
 248   } u;
 249 };
 250
 251
 252 struct Sequence
 253 {
 254   inline void closure (hb_closure_context_t *c) const
 255   {
 256     TRACE_CLOSURE (this);
 257     unsigned int count = substitute.len;
 258     for (unsigned int i = 0; i < count; i++)
 259       c->glyphs->add (substitute[i]);
 260   }
 261
 262   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 263   {
 264     TRACE_COLLECT_GLYPHS (this);
 265     unsigned int count = substitute.len;
 266     for (unsigned int i = 0; i < count; i++)
 267       c->output->add (substitute[i]);
 268   }
 269
 270   inline bool apply (hb_apply_context_t *c) const
 271   {
 272     TRACE_APPLY (this);
 273     if (unlikely (!substitute.len)) return TRACE_RETURN (false);
 274
 275     unsigned int klass = _hb_glyph_info_is_ligature (&c->buffer->cur()) ?
 276                          HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH : 0;
 277     unsigned int count = substitute.len;
 278     if (count == 1) /* Special-case to make it in-place. */
 279     {
 280       c->replace_glyph (substitute.array[0]);
 281     }
 282     else
 283     {
 284       for (unsigned int i = 0; i < count; i++) {
 285         _hb_glyph_info_set_lig_props_for_component (&c->buffer->cur(), i);
 286         c->output_glyph (substitute.array[i], klass);
 287       }
 288       c->buffer->skip_glyph ();
 289     }
 290
 291     return TRACE_RETURN (true);
 292   }
 293
 294   inline bool serialize (hb_serialize_context_t *c,
 295                          Supplier<GlyphID> &glyphs,
 296                          unsigned int num_glyphs)
 297   {
 298     TRACE_SERIALIZE (this);
 299     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
 300     if (unlikely (!substitute.serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
 301     return TRACE_RETURN (true);
 302   }
 303
 304   inline bool sanitize (hb_sanitize_context_t *c) {
 305     TRACE_SANITIZE (this);
 306     return TRACE_RETURN (substitute.sanitize (c));
 307   }
 308
 309   protected:
 310   ArrayOf<GlyphID>
 311                 substitute;             /* String of GlyphIDs to substitute */
 312   public:
 313   DEFINE_SIZE_ARRAY (2, substitute);
 314 };
 315
 316 struct MultipleSubstFormat1
 317 {
 318   inline void closure (hb_closure_context_t *c) const
 319   {
 320     TRACE_CLOSURE (this);
 321     Coverage::Iter iter;
 322     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 323       if (c->glyphs->has (iter.get_glyph ()))
 324         (this+sequence[iter.get_coverage ()]).closure (c);
 325     }
 326   }
 327
 328   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 329   {
 330     TRACE_COLLECT_GLYPHS (this);
 331     (this+coverage).add_coverage (c->input);
 332     unsigned int count = sequence.len;
 333     for (unsigned int i = 0; i < count; i++)
 334         (this+sequence[i]).collect_glyphs (c);
 335   }
 336
 337   inline const Coverage &get_coverage (void) const
 338   {
 339     return this+coverage;
 340   }
 341
 342   inline bool would_apply (hb_would_apply_context_t *c) const
 343   {
 344     TRACE_WOULD_APPLY (this);
 345     return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
 346   }
 347
 348   inline bool apply (hb_apply_context_t *c) const
 349   {
 350     TRACE_APPLY (this);
 351
 352     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
 353     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 354
 355     return TRACE_RETURN ((this+sequence[index]).apply (c));
 356   }
 357
 358   inline bool serialize (hb_serialize_context_t *c,
 359                          Supplier<GlyphID> &glyphs,
 360                          Supplier<unsigned int> &substitute_len_list,
 361                          unsigned int num_glyphs,
 362                          Supplier<GlyphID> &substitute_glyphs_list)
 363   {
 364     TRACE_SERIALIZE (this);
 365     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
 366     if (unlikely (!sequence.serialize (c, num_glyphs))) return TRACE_RETURN (false);
 367     for (unsigned int i = 0; i < num_glyphs; i++)
 368       if (unlikely (!sequence[i].serialize (c, this).serialize (c,
 369                                                                 substitute_glyphs_list,
 370                                                                 substitute_len_list[i]))) return TRACE_RETURN (false);
 371     substitute_len_list.advance (num_glyphs);
 372     if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
 373     return TRACE_RETURN (true);
 374   }
 375
 376   inline bool sanitize (hb_sanitize_context_t *c) {
 377     TRACE_SANITIZE (this);
 378     return TRACE_RETURN (coverage.sanitize (c, this) && sequence.sanitize (c, this));
 379   }
 380
 381   protected:
 382   USHORT        format;                 /* Format identifier--format = 1 */
 383   OffsetTo<Coverage>
 384                 coverage;               /* Offset to Coverage table--from
 385                                          * beginning of Substitution table */
 386   OffsetArrayOf<Sequence>
 387                 sequence;               /* Array of Sequence tables
 388                                          * ordered by Coverage Index */
 389   public:
 390   DEFINE_SIZE_ARRAY (6, sequence);
 391 };
 392
 393 struct MultipleSubst
 394 {
 395   inline bool serialize (hb_serialize_context_t *c,
 396                          Supplier<GlyphID> &glyphs,
 397                          Supplier<unsigned int> &substitute_len_list,
 398                          unsigned int num_glyphs,
 399                          Supplier<GlyphID> &substitute_glyphs_list)
 400   {
 401     TRACE_SERIALIZE (this);
 402     if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
 403     unsigned int format = 1;
 404     u.format.set (format);
 405     switch (u.format) {
 406     case 1: return TRACE_RETURN (u.format1.serialize (c, glyphs, substitute_len_list, num_glyphs, substitute_glyphs_list));
 407     default:return TRACE_RETURN (false);
 408     }
 409   }
 410
 411   template <typename context_t>
 412   inline typename context_t::return_t dispatch (context_t *c) const
 413   {
 414     TRACE_DISPATCH (this);
 415     switch (u.format) {
 416     case 1: return TRACE_RETURN (c->dispatch (u.format1));
 417     default:return TRACE_RETURN (c->default_return_value ());
 418     }
 419   }
 420
 421   inline bool sanitize (hb_sanitize_context_t *c) {
 422     TRACE_SANITIZE (this);
 423     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
 424     switch (u.format) {
 425     case 1: return TRACE_RETURN (u.format1.sanitize (c));
 426     default:return TRACE_RETURN (true);
 427     }
 428   }
 429
 430   protected:
 431   union {
 432   USHORT                format;         /* Format identifier */
 433   MultipleSubstFormat1  format1;
 434   } u;
 435 };
 436
 437
 438 typedef ArrayOf<GlyphID> AlternateSet;  /* Array of alternate GlyphIDs--in
 439                                          * arbitrary order */
 440
 441 struct AlternateSubstFormat1
 442 {
 443   inline void closure (hb_closure_context_t *c) const
 444   {
 445     TRACE_CLOSURE (this);
 446     Coverage::Iter iter;
 447     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 448       if (c->glyphs->has (iter.get_glyph ())) {
 449         const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
 450         unsigned int count = alt_set.len;
 451         for (unsigned int i = 0; i < count; i++)
 452           c->glyphs->add (alt_set[i]);
 453       }
 454     }
 455   }
 456
 457   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 458   {
 459     TRACE_COLLECT_GLYPHS (this);
 460     Coverage::Iter iter;
 461     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 462       c->input->add (iter.get_glyph ());
 463       const AlternateSet &alt_set = this+alternateSet[iter.get_coverage ()];
 464       unsigned int count = alt_set.len;
 465       for (unsigned int i = 0; i < count; i++)
 466         c->output->add (alt_set[i]);
 467     }
 468   }
 469
 470   inline const Coverage &get_coverage (void) const
 471   {
 472     return this+coverage;
 473   }
 474
 475   inline bool would_apply (hb_would_apply_context_t *c) const
 476   {
 477     TRACE_WOULD_APPLY (this);
 478     return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
 479   }
 480
 481   inline bool apply (hb_apply_context_t *c) const
 482   {
 483     TRACE_APPLY (this);
 484     hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
 485
 486     unsigned int index = (this+coverage).get_coverage (glyph_id);
 487     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 488
 489     const AlternateSet &alt_set = this+alternateSet[index];
 490
 491     if (unlikely (!alt_set.len)) return TRACE_RETURN (false);
 492
 493     hb_mask_t glyph_mask = c->buffer->cur().mask;
 494     hb_mask_t lookup_mask = c->lookup_mask;
 495
 496     /* Note: This breaks badly if two features enabled this lookup together. */
 497     unsigned int shift = _hb_ctz (lookup_mask);
 498     unsigned int alt_index = ((lookup_mask & glyph_mask) >> shift);
 499
 500     if (unlikely (alt_index > alt_set.len || alt_index == 0)) return TRACE_RETURN (false);
 501
 502     glyph_id = alt_set[alt_index - 1];
 503
 504     c->replace_glyph (glyph_id);
 505
 506     return TRACE_RETURN (true);
 507   }
 508
 509   inline bool serialize (hb_serialize_context_t *c,
 510                          Supplier<GlyphID> &glyphs,
 511                          Supplier<unsigned int> &alternate_len_list,
 512                          unsigned int num_glyphs,
 513                          Supplier<GlyphID> &alternate_glyphs_list)
 514   {
 515     TRACE_SERIALIZE (this);
 516     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
 517     if (unlikely (!alternateSet.serialize (c, num_glyphs))) return TRACE_RETURN (false);
 518     for (unsigned int i = 0; i < num_glyphs; i++)
 519       if (unlikely (!alternateSet[i].serialize (c, this).serialize (c,
 520                                                                     alternate_glyphs_list,
 521                                                                     alternate_len_list[i]))) return TRACE_RETURN (false);
 522     alternate_len_list.advance (num_glyphs);
 523     if (unlikely (!coverage.serialize (c, this).serialize (c, glyphs, num_glyphs))) return TRACE_RETURN (false);
 524     return TRACE_RETURN (true);
 525   }
 526
 527   inline bool sanitize (hb_sanitize_context_t *c) {
 528     TRACE_SANITIZE (this);
 529     return TRACE_RETURN (coverage.sanitize (c, this) && alternateSet.sanitize (c, this));
 530   }
 531
 532   protected:
 533   USHORT        format;                 /* Format identifier--format = 1 */
 534   OffsetTo<Coverage>
 535                 coverage;               /* Offset to Coverage table--from
 536                                          * beginning of Substitution table */
 537   OffsetArrayOf<AlternateSet>
 538                 alternateSet;           /* Array of AlternateSet tables
 539                                          * ordered by Coverage Index */
 540   public:
 541   DEFINE_SIZE_ARRAY (6, alternateSet);
 542 };
 543
 544 struct AlternateSubst
 545 {
 546   inline bool serialize (hb_serialize_context_t *c,
 547                          Supplier<GlyphID> &glyphs,
 548                          Supplier<unsigned int> &alternate_len_list,
 549                          unsigned int num_glyphs,
 550                          Supplier<GlyphID> &alternate_glyphs_list)
 551   {
 552     TRACE_SERIALIZE (this);
 553     if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
 554     unsigned int format = 1;
 555     u.format.set (format);
 556     switch (u.format) {
 557     case 1: return TRACE_RETURN (u.format1.serialize (c, glyphs, alternate_len_list, num_glyphs, alternate_glyphs_list));
 558     default:return TRACE_RETURN (false);
 559     }
 560   }
 561
 562   template <typename context_t>
 563   inline typename context_t::return_t dispatch (context_t *c) const
 564   {
 565     TRACE_DISPATCH (this);
 566     switch (u.format) {
 567     case 1: return TRACE_RETURN (c->dispatch (u.format1));
 568     default:return TRACE_RETURN (c->default_return_value ());
 569     }
 570   }
 571
 572   inline bool sanitize (hb_sanitize_context_t *c) {
 573     TRACE_SANITIZE (this);
 574     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
 575     switch (u.format) {
 576     case 1: return TRACE_RETURN (u.format1.sanitize (c));
 577     default:return TRACE_RETURN (true);
 578     }
 579   }
 580
 581   protected:
 582   union {
 583   USHORT                format;         /* Format identifier */
 584   AlternateSubstFormat1 format1;
 585   } u;
 586 };
 587
 588
 589 struct Ligature
 590 {
 591   inline void closure (hb_closure_context_t *c) const
 592   {
 593     TRACE_CLOSURE (this);
 594     unsigned int count = component.len;
 595     for (unsigned int i = 1; i < count; i++)
 596       if (!c->glyphs->has (component[i]))
 597         return;
 598     c->glyphs->add (ligGlyph);
 599   }
 600
 601   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 602   {
 603     TRACE_COLLECT_GLYPHS (this);
 604     unsigned int count = component.len;
 605     for (unsigned int i = 1; i < count; i++)
 606       c->input->add (component[i]);
 607     c->output->add (ligGlyph);
 608   }
 609
 610   inline bool would_apply (hb_would_apply_context_t *c) const
 611   {
 612     TRACE_WOULD_APPLY (this);
 613     if (c->len != component.len)
 614       return TRACE_RETURN (false);
 615
 616     for (unsigned int i = 1; i < c->len; i++)
 617       if (likely (c->glyphs[i] != component[i]))
 618         return TRACE_RETURN (false);
 619
 620     return TRACE_RETURN (true);
 621   }
 622
 623   inline bool apply (hb_apply_context_t *c) const
 624   {
 625     TRACE_APPLY (this);
 626     unsigned int count = component.len;
 627     if (unlikely (count < 1)) return TRACE_RETURN (false);
 628
 629     bool is_mark_ligature = false;
 630     unsigned int total_component_count = 0;
 631
 632     unsigned int match_length = 0;
 633     unsigned int match_positions[MAX_CONTEXT_LENGTH];
 634
 635     if (likely (!match_input (c, count,
 636                               &component[1],
 637                               match_glyph,
 638                               NULL,
 639                               &match_length,
 640                               match_positions,
 641                               &is_mark_ligature,
 642                               &total_component_count)))
 643       return TRACE_RETURN (false);
 644
 645     ligate_input (c,
 646                   count,
 647                   match_positions,
 648                   match_length,
 649                   ligGlyph,
 650                   is_mark_ligature,
 651                   total_component_count);
 652
 653     return TRACE_RETURN (true);
 654   }
 655
 656   inline bool serialize (hb_serialize_context_t *c,
 657                          GlyphID ligature,
 658                          Supplier<GlyphID> &components, /* Starting from second */
 659                          unsigned int num_components /* Including first component */)
 660   {
 661     TRACE_SERIALIZE (this);
 662     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
 663     ligGlyph = ligature;
 664     if (unlikely (!component.serialize (c, components, num_components))) return TRACE_RETURN (false);
 665     return TRACE_RETURN (true);
 666   }
 667
 668   public:
 669   inline bool sanitize (hb_sanitize_context_t *c) {
 670     TRACE_SANITIZE (this);
 671     return TRACE_RETURN (ligGlyph.sanitize (c) && component.sanitize (c));
 672   }
 673
 674   protected:
 675   GlyphID       ligGlyph;               /* GlyphID of ligature to substitute */
 676   HeadlessArrayOf<GlyphID>
 677                 component;              /* Array of component GlyphIDs--start
 678                                          * with the second  component--ordered
 679                                          * in writing direction */
 680   public:
 681   DEFINE_SIZE_ARRAY (4, component);
 682 };
 683
 684 struct LigatureSet
 685 {
 686   inline void closure (hb_closure_context_t *c) const
 687   {
 688     TRACE_CLOSURE (this);
 689     unsigned int num_ligs = ligature.len;
 690     for (unsigned int i = 0; i < num_ligs; i++)
 691       (this+ligature[i]).closure (c);
 692   }
 693
 694   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 695   {
 696     TRACE_COLLECT_GLYPHS (this);
 697     unsigned int num_ligs = ligature.len;
 698     for (unsigned int i = 0; i < num_ligs; i++)
 699       (this+ligature[i]).collect_glyphs (c);
 700   }
 701
 702   inline bool would_apply (hb_would_apply_context_t *c) const
 703   {
 704     TRACE_WOULD_APPLY (this);
 705     unsigned int num_ligs = ligature.len;
 706     for (unsigned int i = 0; i < num_ligs; i++)
 707     {
 708       const Ligature &lig = this+ligature[i];
 709       if (lig.would_apply (c))
 710         return TRACE_RETURN (true);
 711     }
 712     return TRACE_RETURN (false);
 713   }
 714
 715   inline bool apply (hb_apply_context_t *c) const
 716   {
 717     TRACE_APPLY (this);
 718     unsigned int num_ligs = ligature.len;
 719     for (unsigned int i = 0; i < num_ligs; i++)
 720     {
 721       const Ligature &lig = this+ligature[i];
 722       if (lig.apply (c)) return TRACE_RETURN (true);
 723     }
 724
 725     return TRACE_RETURN (false);
 726   }
 727
 728   inline bool serialize (hb_serialize_context_t *c,
 729                          Supplier<GlyphID> &ligatures,
 730                          Supplier<unsigned int> &component_count_list,
 731                          unsigned int num_ligatures,
 732                          Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
 733   {
 734     TRACE_SERIALIZE (this);
 735     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
 736     if (unlikely (!ligature.serialize (c, num_ligatures))) return TRACE_RETURN (false);
 737     for (unsigned int i = 0; i < num_ligatures; i++)
 738       if (unlikely (!ligature[i].serialize (c, this).serialize (c,
 739                                                                 ligatures[i],
 740                                                                 component_list,
 741                                                                 component_count_list[i]))) return TRACE_RETURN (false);
 742     ligatures.advance (num_ligatures);
 743     component_count_list.advance (num_ligatures);
 744     return TRACE_RETURN (true);
 745   }
 746
 747   inline bool sanitize (hb_sanitize_context_t *c) {
 748     TRACE_SANITIZE (this);
 749     return TRACE_RETURN (ligature.sanitize (c, this));
 750   }
 751
 752   protected:
 753   OffsetArrayOf<Ligature>
 754                 ligature;               /* Array LigatureSet tables
 755                                          * ordered by preference */
 756   public:
 757   DEFINE_SIZE_ARRAY (2, ligature);
 758 };
 759
 760 struct LigatureSubstFormat1
 761 {
 762   inline void closure (hb_closure_context_t *c) const
 763   {
 764     TRACE_CLOSURE (this);
 765     Coverage::Iter iter;
 766     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 767       if (c->glyphs->has (iter.get_glyph ()))
 768         (this+ligatureSet[iter.get_coverage ()]).closure (c);
 769     }
 770   }
 771
 772   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 773   {
 774     TRACE_COLLECT_GLYPHS (this);
 775     Coverage::Iter iter;
 776     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 777       c->input->add (iter.get_glyph ());
 778       (this+ligatureSet[iter.get_coverage ()]).collect_glyphs (c);
 779     }
 780   }
 781
 782   inline const Coverage &get_coverage (void) const
 783   {
 784     return this+coverage;
 785   }
 786
 787   inline bool would_apply (hb_would_apply_context_t *c) const
 788   {
 789     TRACE_WOULD_APPLY (this);
 790     unsigned int index = (this+coverage).get_coverage (c->glyphs[0]);
 791     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 792
 793     const LigatureSet &lig_set = this+ligatureSet[index];
 794     return TRACE_RETURN (lig_set.would_apply (c));
 795   }
 796
 797   inline bool apply (hb_apply_context_t *c) const
 798   {
 799     TRACE_APPLY (this);
 800     hb_codepoint_t glyph_id = c->buffer->cur().codepoint;
 801
 802     unsigned int index = (this+coverage).get_coverage (glyph_id);
 803     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 804
 805     const LigatureSet &lig_set = this+ligatureSet[index];
 806     return TRACE_RETURN (lig_set.apply (c));
 807   }
 808
 809   inline bool serialize (hb_serialize_context_t *c,
 810                          Supplier<GlyphID> &first_glyphs,
 811                          Supplier<unsigned int> &ligature_per_first_glyph_count_list,
 812                          unsigned int num_first_glyphs,
 813                          Supplier<GlyphID> &ligatures_list,
 814                          Supplier<unsigned int> &component_count_list,
 815                          Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
 816   {
 817     TRACE_SERIALIZE (this);
 818     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
 819     if (unlikely (!ligatureSet.serialize (c, num_first_glyphs))) return TRACE_RETURN (false);
 820     for (unsigned int i = 0; i < num_first_glyphs; i++)
 821       if (unlikely (!ligatureSet[i].serialize (c, this).serialize (c,
 822                                                                    ligatures_list,
 823                                                                    component_count_list,
 824                                                                    ligature_per_first_glyph_count_list[i],
 825                                                                    component_list))) return TRACE_RETURN (false);
 826     ligature_per_first_glyph_count_list.advance (num_first_glyphs);
 827     if (unlikely (!coverage.serialize (c, this).serialize (c, first_glyphs, num_first_glyphs))) return TRACE_RETURN (false);
 828     return TRACE_RETURN (true);
 829   }
 830
 831   inline bool sanitize (hb_sanitize_context_t *c) {
 832     TRACE_SANITIZE (this);
 833     return TRACE_RETURN (coverage.sanitize (c, this) && ligatureSet.sanitize (c, this));
 834   }
 835
 836   protected:
 837   USHORT        format;                 /* Format identifier--format = 1 */
 838   OffsetTo<Coverage>
 839                 coverage;               /* Offset to Coverage table--from
 840                                          * beginning of Substitution table */
 841   OffsetArrayOf<LigatureSet>
 842                 ligatureSet;            /* Array LigatureSet tables
 843                                          * ordered by Coverage Index */
 844   public:
 845   DEFINE_SIZE_ARRAY (6, ligatureSet);
 846 };
 847
 848 struct LigatureSubst
 849 {
 850   inline bool serialize (hb_serialize_context_t *c,
 851                          Supplier<GlyphID> &first_glyphs,
 852                          Supplier<unsigned int> &ligature_per_first_glyph_count_list,
 853                          unsigned int num_first_glyphs,
 854                          Supplier<GlyphID> &ligatures_list,
 855                          Supplier<unsigned int> &component_count_list,
 856                          Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
 857   {
 858     TRACE_SERIALIZE (this);
 859     if (unlikely (!c->extend_min (u.format))) return TRACE_RETURN (false);
 860     unsigned int format = 1;
 861     u.format.set (format);
 862     switch (u.format) {
 863     case 1: return TRACE_RETURN (u.format1.serialize (c, first_glyphs, ligature_per_first_glyph_count_list, num_first_glyphs,
 864                                                       ligatures_list, component_count_list, component_list));
 865     default:return TRACE_RETURN (false);
 866     }
 867   }
 868
 869   template <typename context_t>
 870   inline typename context_t::return_t dispatch (context_t *c) const
 871   {
 872     TRACE_DISPATCH (this);
 873     switch (u.format) {
 874     case 1: return TRACE_RETURN (c->dispatch (u.format1));
 875     default:return TRACE_RETURN (c->default_return_value ());
 876     }
 877   }
 878
 879   inline bool sanitize (hb_sanitize_context_t *c) {
 880     TRACE_SANITIZE (this);
 881     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
 882     switch (u.format) {
 883     case 1: return TRACE_RETURN (u.format1.sanitize (c));
 884     default:return TRACE_RETURN (true);
 885     }
 886   }
 887
 888   protected:
 889   union {
 890   USHORT                format;         /* Format identifier */
 891   LigatureSubstFormat1  format1;
 892   } u;
 893 };
 894
 895
 896 struct ContextSubst : Context {};
 897
 898 struct ChainContextSubst : ChainContext {};
 899
 900 struct ExtensionSubst : Extension<ExtensionSubst>
 901 {
 902   typedef struct SubstLookupSubTable LookupSubTable;
 903
 904   inline bool is_reverse (void) const;
 905 };
 906
 907
 908 struct ReverseChainSingleSubstFormat1
 909 {
 910   inline void closure (hb_closure_context_t *c) const
 911   {
 912     TRACE_CLOSURE (this);
 913     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
 914
 915     unsigned int count;
 916
 917     count = backtrack.len;
 918     for (unsigned int i = 0; i < count; i++)
 919       if (!(this+backtrack[i]).intersects (c->glyphs))
 920         return;
 921
 922     count = lookahead.len;
 923     for (unsigned int i = 0; i < count; i++)
 924       if (!(this+lookahead[i]).intersects (c->glyphs))
 925         return;
 926
 927     const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
 928     Coverage::Iter iter;
 929     for (iter.init (this+coverage); iter.more (); iter.next ()) {
 930       if (c->glyphs->has (iter.get_glyph ()))
 931         c->glyphs->add (substitute[iter.get_coverage ()]);
 932     }
 933   }
 934
 935   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
 936   {
 937     TRACE_COLLECT_GLYPHS (this);
 938
 939     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
 940
 941     unsigned int count;
 942
 943     (this+coverage).add_coverage (c->input);
 944
 945     count = backtrack.len;
 946     for (unsigned int i = 0; i < count; i++)
 947       (this+backtrack[i]).add_coverage (c->before);
 948
 949     count = lookahead.len;
 950     for (unsigned int i = 0; i < count; i++)
 951       (this+lookahead[i]).add_coverage (c->after);
 952
 953     const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
 954     count = substitute.len;
 955     for (unsigned int i = 0; i < count; i++)
 956       c->output->add (substitute[i]);
 957   }
 958
 959   inline const Coverage &get_coverage (void) const
 960   {
 961     return this+coverage;
 962   }
 963
 964   inline bool would_apply (hb_would_apply_context_t *c) const
 965   {
 966     TRACE_WOULD_APPLY (this);
 967     return TRACE_RETURN (c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED);
 968   }
 969
 970   inline bool apply (hb_apply_context_t *c) const
 971   {
 972     TRACE_APPLY (this);
 973     if (unlikely (c->nesting_level_left != MAX_NESTING_LEVEL))
 974       return TRACE_RETURN (false); /* No chaining to this type */
 975
 976     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
 977     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
 978
 979     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
 980     const ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
 981
 982     if (match_backtrack (c,
 983                          backtrack.len, (USHORT *) backtrack.array,
 984                          match_coverage, this) &&
 985         match_lookahead (c,
 986                          lookahead.len, (USHORT *) lookahead.array,
 987                          match_coverage, this,
 988                          1))
 989     {
 990       c->replace_glyph_inplace (substitute[index]);
 991       /* Note: We DON'T decrease buffer->idx.  The main loop does it
 992        * for us.  This is useful for preventing surprises if someone
 993        * calls us through a Context lookup. */
 994       return TRACE_RETURN (true);
 995     }
 996
 997     return TRACE_RETURN (false);
 998   }
 999
1000   inline bool sanitize (hb_sanitize_context_t *c) {
1001     TRACE_SANITIZE (this);
1002     if (!(coverage.sanitize (c, this) && backtrack.sanitize (c, this)))
1003       return TRACE_RETURN (false);
1004     OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
1005     if (!lookahead.sanitize (c, this))
1006       return TRACE_RETURN (false);
1007     ArrayOf<GlyphID> &substitute = StructAfter<ArrayOf<GlyphID> > (lookahead);
1008     return TRACE_RETURN (substitute.sanitize (c));
1009   }
1010
1011   protected:
1012   USHORT        format;                 /* Format identifier--format = 1 */
1013   OffsetTo<Coverage>
1014                 coverage;               /* Offset to Coverage table--from
1015                                          * beginning of table */
1016   OffsetArrayOf<Coverage>
1017                 backtrack;              /* Array of coverage tables
1018                                          * in backtracking sequence, in  glyph
1019                                          * sequence order */
1020   OffsetArrayOf<Coverage>
1021                 lookaheadX;             /* Array of coverage tables
1022                                          * in lookahead sequence, in glyph
1023                                          * sequence order */
1024   ArrayOf<GlyphID>
1025                 substituteX;            /* Array of substitute
1026                                          * GlyphIDs--ordered by Coverage Index */
1027   public:
1028   DEFINE_SIZE_MIN (10);
1029 };
1030
1031 struct ReverseChainSingleSubst
1032 {
1033   template <typename context_t>
1034   inline typename context_t::return_t dispatch (context_t *c) const
1035   {
1036     TRACE_DISPATCH (this);
1037     switch (u.format) {
1038     case 1: return TRACE_RETURN (c->dispatch (u.format1));
1039     default:return TRACE_RETURN (c->default_return_value ());
1040     }
1041   }
1042
1043   inline bool sanitize (hb_sanitize_context_t *c) {
1044     TRACE_SANITIZE (this);
1045     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
1046     switch (u.format) {
1047     case 1: return TRACE_RETURN (u.format1.sanitize (c));
1048     default:return TRACE_RETURN (true);
1049     }
1050   }
1051
1052   protected:
1053   union {
1054   USHORT                                format;         /* Format identifier */
1055   ReverseChainSingleSubstFormat1        format1;
1056   } u;
1057 };
1058
1059
1060
1061 /*
1062  * SubstLookup
1063  */
1064
1065 struct SubstLookupSubTable
1066 {
1067   friend struct SubstLookup;
1068
1069   enum Type {
1070     Single              = 1,
1071     Multiple            = 2,
1072     Alternate           = 3,
1073     Ligature            = 4,
1074     Context             = 5,
1075     ChainContext        = 6,
1076     Extension           = 7,
1077     ReverseChainSingle  = 8
1078   };
1079
1080   template <typename context_t>
1081   inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
1082   {
1083     TRACE_DISPATCH (this);
1084     switch (lookup_type) {
1085     case Single:                return TRACE_RETURN (u.single.dispatch (c));
1086     case Multiple:              return TRACE_RETURN (u.multiple.dispatch (c));
1087     case Alternate:             return TRACE_RETURN (u.alternate.dispatch (c));
1088     case Ligature:              return TRACE_RETURN (u.ligature.dispatch (c));
1089     case Context:               return TRACE_RETURN (u.context.dispatch (c));
1090     case ChainContext:          return TRACE_RETURN (u.chainContext.dispatch (c));
1091     case Extension:             return TRACE_RETURN (u.extension.dispatch (c));
1092     case ReverseChainSingle:    return TRACE_RETURN (u.reverseChainContextSingle.dispatch (c));
1093     default:                    return TRACE_RETURN (c->default_return_value ());
1094     }
1095   }
1096
1097   inline bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) {
1098     TRACE_SANITIZE (this);
1099     if (!u.header.sub_format.sanitize (c))
1100       return TRACE_RETURN (false);
1101     switch (lookup_type) {
1102     case Single:                return TRACE_RETURN (u.single.sanitize (c));
1103     case Multiple:              return TRACE_RETURN (u.multiple.sanitize (c));
1104     case Alternate:             return TRACE_RETURN (u.alternate.sanitize (c));
1105     case Ligature:              return TRACE_RETURN (u.ligature.sanitize (c));
1106     case Context:               return TRACE_RETURN (u.context.sanitize (c));
1107     case ChainContext:          return TRACE_RETURN (u.chainContext.sanitize (c));
1108     case Extension:             return TRACE_RETURN (u.extension.sanitize (c));
1109     case ReverseChainSingle:    return TRACE_RETURN (u.reverseChainContextSingle.sanitize (c));
1110     default:                    return TRACE_RETURN (true);
1111     }
1112   }
1113
1114   protected:
1115   union {
1116   struct {
1117     USHORT                      sub_format;
1118   } header;
1119   SingleSubst                   single;
1120   MultipleSubst                 multiple;
1121   AlternateSubst                alternate;
1122   LigatureSubst                 ligature;
1123   ContextSubst                  context;
1124   ChainContextSubst             chainContext;
1125   ExtensionSubst                extension;
1126   ReverseChainSingleSubst       reverseChainContextSingle;
1127   } u;
1128   public:
1129   DEFINE_SIZE_UNION (2, header.sub_format);
1130 };
1131
1132
1133 struct SubstLookup : Lookup
1134 {
1135   inline const SubstLookupSubTable& get_subtable (unsigned int i) const
1136   { return this+CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i]; }
1137
1138   inline static bool lookup_type_is_reverse (unsigned int lookup_type)
1139   { return lookup_type == SubstLookupSubTable::ReverseChainSingle; }
1140
1141   inline bool is_reverse (void) const
1142   {
1143     unsigned int type = get_type ();
1144     if (unlikely (type == SubstLookupSubTable::Extension))
1145       return CastR<ExtensionSubst> (get_subtable(0)).is_reverse ();
1146     return lookup_type_is_reverse (type);
1147   }
1148
1149   inline hb_closure_context_t::return_t closure (hb_closure_context_t *c) const
1150   {
1151     TRACE_CLOSURE (this);
1152     c->set_recurse_func (dispatch_recurse_func<hb_closure_context_t>);
1153     return TRACE_RETURN (dispatch (c));
1154   }
1155
1156   inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
1157   {
1158     TRACE_COLLECT_GLYPHS (this);
1159     c->set_recurse_func (dispatch_recurse_func<hb_collect_glyphs_context_t>);
1160     return TRACE_RETURN (dispatch (c));
1161   }
1162
1163   template <typename set_t>
1164   inline void add_coverage (set_t *glyphs) const
1165   {
1166     hb_get_coverage_context_t c;
1167     const Coverage *last = NULL;
1168     unsigned int count = get_subtable_count ();
1169     for (unsigned int i = 0; i < count; i++) {
1170       const Coverage *coverage = &get_subtable (i).dispatch (&c, get_type ());
1171       if (coverage != last) {
1172         coverage->add_coverage (glyphs);
1173         last = coverage;
1174       }
1175     }
1176   }
1177
1178   inline bool would_apply (hb_would_apply_context_t *c, const hb_set_digest_t *digest) const
1179   {
1180     TRACE_WOULD_APPLY (this);
1181     if (unlikely (!c->len))  return TRACE_RETURN (false);
1182     if (!digest->may_have (c->glyphs[0]))  return TRACE_RETURN (false);
1183       return TRACE_RETURN (dispatch (c));
1184   }
1185
1186   inline bool apply_once (hb_apply_context_t *c) const
1187   {
1188     TRACE_APPLY (this);
1189     if (!c->check_glyph_property (&c->buffer->cur(), c->lookup_props))
1190       return TRACE_RETURN (false);
1191     return TRACE_RETURN (dispatch (c));
1192   }
1193
1194   static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
1195
1196   inline SubstLookupSubTable& serialize_subtable (hb_serialize_context_t *c,
1197                                                   unsigned int i)
1198   { return CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable)[i].serialize (c, this); }
1199
1200   inline bool serialize_single (hb_serialize_context_t *c,
1201                                 uint32_t lookup_props,
1202                                 Supplier<GlyphID> &glyphs,
1203                                 Supplier<GlyphID> &substitutes,
1204                                 unsigned int num_glyphs)
1205   {
1206     TRACE_SERIALIZE (this);
1207     if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Single, lookup_props, 1))) return TRACE_RETURN (false);
1208     return TRACE_RETURN (serialize_subtable (c, 0).u.single.serialize (c, glyphs, substitutes, num_glyphs));
1209   }
1210
1211   inline bool serialize_multiple (hb_serialize_context_t *c,
1212                                   uint32_t lookup_props,
1213                                   Supplier<GlyphID> &glyphs,
1214                                   Supplier<unsigned int> &substitute_len_list,
1215                                   unsigned int num_glyphs,
1216                                   Supplier<GlyphID> &substitute_glyphs_list)
1217   {
1218     TRACE_SERIALIZE (this);
1219     if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Multiple, lookup_props, 1))) return TRACE_RETURN (false);
1220     return TRACE_RETURN (serialize_subtable (c, 0).u.multiple.serialize (c, glyphs, substitute_len_list, num_glyphs,
1221                                                                          substitute_glyphs_list));
1222   }
1223
1224   inline bool serialize_alternate (hb_serialize_context_t *c,
1225                                    uint32_t lookup_props,
1226                                    Supplier<GlyphID> &glyphs,
1227                                    Supplier<unsigned int> &alternate_len_list,
1228                                    unsigned int num_glyphs,
1229                                    Supplier<GlyphID> &alternate_glyphs_list)
1230   {
1231     TRACE_SERIALIZE (this);
1232     if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Alternate, lookup_props, 1))) return TRACE_RETURN (false);
1233     return TRACE_RETURN (serialize_subtable (c, 0).u.alternate.serialize (c, glyphs, alternate_len_list, num_glyphs,
1234                                                                           alternate_glyphs_list));
1235   }
1236
1237   inline bool serialize_ligature (hb_serialize_context_t *c,
1238                                   uint32_t lookup_props,
1239                                   Supplier<GlyphID> &first_glyphs,
1240                                   Supplier<unsigned int> &ligature_per_first_glyph_count_list,
1241                                   unsigned int num_first_glyphs,
1242                                   Supplier<GlyphID> &ligatures_list,
1243                                   Supplier<unsigned int> &component_count_list,
1244                                   Supplier<GlyphID> &component_list /* Starting from second for each ligature */)
1245   {
1246     TRACE_SERIALIZE (this);
1247     if (unlikely (!Lookup::serialize (c, SubstLookupSubTable::Ligature, lookup_props, 1))) return TRACE_RETURN (false);
1248     return TRACE_RETURN (serialize_subtable (c, 0).u.ligature.serialize (c, first_glyphs, ligature_per_first_glyph_count_list, num_first_glyphs,
1249                                                                          ligatures_list, component_count_list, component_list));
1250   }
1251
1252   template <typename context_t>
1253   static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
1254
1255   template <typename context_t>
1256   inline typename context_t::return_t dispatch (context_t *c) const
1257   {
1258     TRACE_DISPATCH (this);
1259     unsigned int lookup_type = get_type ();
1260     unsigned int count = get_subtable_count ();
1261     for (unsigned int i = 0; i < count; i++) {
1262       typename context_t::return_t r = get_subtable (i).dispatch (c, lookup_type);
1263       if (c->stop_sublookup_iteration (r))
1264         return TRACE_RETURN (r);
1265     }
1266     return TRACE_RETURN (c->default_return_value ());
1267   }
1268
1269   inline bool sanitize (hb_sanitize_context_t *c)
1270   {
1271     TRACE_SANITIZE (this);
1272     if (unlikely (!Lookup::sanitize (c))) return TRACE_RETURN (false);
1273     OffsetArrayOf<SubstLookupSubTable> &list = CastR<OffsetArrayOf<SubstLookupSubTable> > (subTable);
1274     if (unlikely (!list.sanitize (c, this, get_type ()))) return TRACE_RETURN (false);
1275
1276     if (unlikely (get_type () == SubstLookupSubTable::Extension))
1277     {
1278       /* The spec says all subtables of an Extension lookup should
1279        * have the same type.  This is specially important if one has
1280        * a reverse type! */
1281       unsigned int type = get_subtable (0).u.extension.get_type ();
1282       unsigned int count = get_subtable_count ();
1283       for (unsigned int i = 1; i < count; i++)
1284         if (get_subtable (i).u.extension.get_type () != type)
1285           return TRACE_RETURN (false);
1286     }
1287     return TRACE_RETURN (true);
1288   }
1289 };
1290
1291 typedef OffsetListOf<SubstLookup> SubstLookupList;
1292
1293 /*
1294  * GSUB -- The Glyph Substitution Table
1295  */
1296
1297 struct GSUB : GSUBGPOS
1298 {
1299   static const hb_tag_t tableTag        = HB_OT_TAG_GSUB;
1300
1301   inline const SubstLookup& get_lookup (unsigned int i) const
1302   { return CastR<SubstLookup> (GSUBGPOS::get_lookup (i)); }
1303
1304   static inline void substitute_start (hb_font_t *font, hb_buffer_t *buffer);
1305   static inline void substitute_finish (hb_font_t *font, hb_buffer_t *buffer);
1306
1307   inline bool sanitize (hb_sanitize_context_t *c) {
1308     TRACE_SANITIZE (this);
1309     if (unlikely (!GSUBGPOS::sanitize (c))) return TRACE_RETURN (false);
1310     OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
1311     return TRACE_RETURN (list.sanitize (c, this));
1312   }
1313   public:
1314   DEFINE_SIZE_STATIC (10);
1315 };
1316
1317
1318 void
1319 GSUB::substitute_start (hb_font_t *font, hb_buffer_t *buffer)
1320 {
1321   _hb_buffer_allocate_gsubgpos_vars (buffer);
1322
1323   const GDEF &gdef = *hb_ot_layout_from_face (font->face)->gdef;
1324   unsigned int count = buffer->len;
1325   for (unsigned int i = 0; i < count; i++)
1326   {
1327     _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
1328     _hb_glyph_info_clear_lig_props (&buffer->info[i]);
1329     buffer->info[i].syllable() = 0;
1330   }
1331 }
1332
1333 void
1334 GSUB::substitute_finish (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer HB_UNUSED)
1335 {
1336 }
1337
1338
1339 /* Out-of-class implementation for methods recursing */
1340
1341 inline bool ExtensionSubst::is_reverse (void) const
1342 {
1343   unsigned int type = get_type ();
1344   if (unlikely (type == SubstLookupSubTable::Extension))
1345     return CastR<ExtensionSubst> (get_subtable<SubstLookupSubTable>()).is_reverse ();
1346   return SubstLookup::lookup_type_is_reverse (type);
1347 }
1348
1349 template <typename context_t>
1350 inline typename context_t::return_t SubstLookup::dispatch_recurse_func (context_t *c, unsigned int lookup_index)
1351 {
1352   const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
1353   const SubstLookup &l = gsub.get_lookup (lookup_index);
1354   return l.dispatch (c);
1355 }
1356
1357 inline bool SubstLookup::apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index)
1358 {
1359   const GSUB &gsub = *(hb_ot_layout_from_face (c->face)->gsub);
1360   const SubstLookup &l = gsub.get_lookup (lookup_index);
1361   unsigned int saved_lookup_props = c->lookup_props;
1362   c->set_lookup (l);
1363   bool ret = l.apply_once (c);
1364   c->lookup_props = saved_lookup_props;
1365   return ret;
1366 }
1367
1368
1369 } /* namespace OT */
1370
1371
1372 #endif /* HB_OT_LAYOUT_GSUB_TABLE_HH */