include/harfbuzz-gsub-private.h

   1 /*
   2  * Copyright (C) 1998-2004  David Turner and Werner Lemberg
   3  * Copyright (C) 2006  Behdad Esfahbod
   4  *
   5  * This is part of HarfBuzz, an OpenType Layout engine 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
  26 #ifndef HARFBUZZ_GSUB_PRIVATE_H
  27 #define HARFBUZZ_GSUB_PRIVATE_H
  28
  29 #include "harfbuzz-impl.h"
  30 #include "harfbuzz-stream-private.h"
  31 #include "harfbuzz-gsub.h"
  32
  33 HB_BEGIN_HEADER
  34
  35
  36 typedef union HB_GSUB_SubTable_  HB_GSUB_SubTable;
  37
  38 /* LookupType 1 */
  39
  40 struct  HB_SingleSubstFormat1_
  41 {
  42   HB_Short  DeltaGlyphID;             /* constant added to get
  43                                          substitution glyph index */
  44 };
  45
  46 typedef struct HB_SingleSubstFormat1_  HB_SingleSubstFormat1;
  47
  48
  49 struct  HB_SingleSubstFormat2_
  50 {
  51   HB_UShort   GlyphCount;             /* number of glyph IDs in
  52                                          Substitute array              */
  53   HB_UShort*  Substitute;             /* array of substitute glyph IDs */
  54 };
  55
  56 typedef struct HB_SingleSubstFormat2_  HB_SingleSubstFormat2;
  57
  58
  59 struct  HB_SingleSubst_
  60 {
  61   HB_UShort     SubstFormat;          /* 1 or 2         */
  62   HB_Coverage  Coverage;             /* Coverage table */
  63
  64   union
  65   {
  66     HB_SingleSubstFormat1  ssf1;
  67     HB_SingleSubstFormat2  ssf2;
  68   } ssf;
  69 };
  70
  71 typedef struct HB_SingleSubst_  HB_SingleSubst;
  72
  73
  74 /* LookupType 2 */
  75
  76 struct  HB_Sequence_
  77 {
  78   HB_UShort   GlyphCount;             /* number of glyph IDs in the
  79                                          Substitute array           */
  80   HB_UShort*  Substitute;             /* string of glyph IDs to
  81                                          substitute                 */
  82 };
  83
  84 typedef struct HB_Sequence_  HB_Sequence;
  85
  86
  87 struct  HB_MultipleSubst_
  88 {
  89   HB_UShort      SubstFormat;         /* always 1                  */
  90   HB_Coverage   Coverage;            /* Coverage table            */
  91   HB_UShort      SequenceCount;       /* number of Sequence tables */
  92   HB_Sequence*  Sequence;            /* array of Sequence tables  */
  93 };
  94
  95 typedef struct HB_MultipleSubst_  HB_MultipleSubst;
  96
  97
  98 /* LookupType 3 */
  99
 100 struct  HB_AlternateSet_
 101 {
 102   HB_UShort   GlyphCount;             /* number of glyph IDs in the
 103                                          Alternate array              */
 104   HB_UShort*  Alternate;              /* array of alternate glyph IDs */
 105 };
 106
 107 typedef struct HB_AlternateSet_  HB_AlternateSet;
 108
 109
 110 struct  HB_AlternateSubst_
 111 {
 112   HB_UShort          SubstFormat;     /* always 1                      */
 113   HB_Coverage       Coverage;        /* Coverage table                */
 114   HB_UShort          AlternateSetCount;
 115                                       /* number of AlternateSet tables */
 116   HB_AlternateSet*  AlternateSet;    /* array of AlternateSet tables  */
 117 };
 118
 119 typedef struct HB_AlternateSubst_  HB_AlternateSubst;
 120
 121
 122 /* LookupType 4 */
 123
 124 struct  HB_Ligature_
 125 {
 126   HB_UShort   LigGlyph;               /* glyphID of ligature
 127                                          to substitute                    */
 128   HB_UShort   ComponentCount;         /* number of components in ligature */
 129   HB_UShort*  Component;              /* array of component glyph IDs     */
 130 };
 131
 132 typedef struct HB_Ligature_  HB_Ligature;
 133
 134
 135 struct  HB_LigatureSet_
 136 {
 137   HB_UShort      LigatureCount;       /* number of Ligature tables */
 138   HB_Ligature*  Ligature;            /* array of Ligature tables  */
 139 };
 140
 141 typedef struct HB_LigatureSet_  HB_LigatureSet;
 142
 143
 144 struct  HB_LigatureSubst_
 145 {
 146   HB_UShort         SubstFormat;      /* always 1                     */
 147   HB_Coverage      Coverage;         /* Coverage table               */
 148   HB_UShort         LigatureSetCount; /* number of LigatureSet tables */
 149   HB_LigatureSet*  LigatureSet;      /* array of LigatureSet tables  */
 150 };
 151
 152 typedef struct HB_LigatureSubst_  HB_LigatureSubst;
 153
 154
 155 /* needed by both lookup type 5 and 6 */
 156
 157 struct  HB_SubstLookupRecord_
 158 {
 159   HB_UShort  SequenceIndex;           /* index into current
 160                                          glyph sequence               */
 161   HB_UShort  LookupListIndex;         /* Lookup to apply to that pos. */
 162 };
 163
 164 typedef struct HB_SubstLookupRecord_  HB_SubstLookupRecord;
 165
 166
 167 /* LookupType 5 */
 168
 169 struct  HB_SubRule_
 170 {
 171   HB_UShort               GlyphCount; /* total number of input glyphs */
 172   HB_UShort               SubstCount; /* number of SubstLookupRecord
 173                                          tables                       */
 174   HB_UShort*              Input;      /* array of input glyph IDs     */
 175   HB_SubstLookupRecord*  SubstLookupRecord;
 176                                       /* array of SubstLookupRecord
 177                                          tables                       */
 178 };
 179
 180 typedef struct HB_SubRule_  HB_SubRule;
 181
 182
 183 struct  HB_SubRuleSet_
 184 {
 185   HB_UShort     SubRuleCount;         /* number of SubRule tables */
 186   HB_SubRule*  SubRule;              /* array of SubRule tables  */
 187 };
 188
 189 typedef struct HB_SubRuleSet_  HB_SubRuleSet;
 190
 191
 192 struct  HB_ContextSubstFormat1_
 193 {
 194   HB_Coverage     Coverage;          /* Coverage table              */
 195   HB_UShort        SubRuleSetCount;   /* number of SubRuleSet tables */
 196   HB_SubRuleSet*  SubRuleSet;        /* array of SubRuleSet tables  */
 197 };
 198
 199 typedef struct HB_ContextSubstFormat1_  HB_ContextSubstFormat1;
 200
 201
 202 struct  HB_SubClassRule_
 203 {
 204   HB_UShort               GlyphCount; /* total number of context classes */
 205   HB_UShort               SubstCount; /* number of SubstLookupRecord
 206                                          tables                          */
 207   HB_UShort*              Class;      /* array of classes                */
 208   HB_SubstLookupRecord*  SubstLookupRecord;
 209                                       /* array of SubstLookupRecord
 210                                          tables                          */
 211 };
 212
 213 typedef struct HB_SubClassRule_  HB_SubClassRule;
 214
 215
 216 struct  HB_SubClassSet_
 217 {
 218   HB_UShort          SubClassRuleCount;
 219                                       /* number of SubClassRule tables */
 220   HB_SubClassRule*  SubClassRule;    /* array of SubClassRule tables  */
 221 };
 222
 223 typedef struct HB_SubClassSet_  HB_SubClassSet;
 224
 225
 226 /* The `MaxContextLength' field is not defined in the TTO specification
 227    but simplifies the implementation of this format.  It holds the
 228    maximal context length used in the context rules.                    */
 229
 230 struct  HB_ContextSubstFormat2_
 231 {
 232   HB_UShort            MaxContextLength;
 233                                       /* maximal context length       */
 234   HB_Coverage         Coverage;      /* Coverage table               */
 235   HB_ClassDefinition  ClassDef;      /* ClassDef table               */
 236   HB_UShort            SubClassSetCount;
 237                                       /* number of SubClassSet tables */
 238   HB_SubClassSet*     SubClassSet;   /* array of SubClassSet tables  */
 239 };
 240
 241 typedef struct HB_ContextSubstFormat2_  HB_ContextSubstFormat2;
 242
 243
 244 struct  HB_ContextSubstFormat3_
 245 {
 246   HB_UShort               GlyphCount; /* number of input glyphs        */
 247   HB_UShort               SubstCount; /* number of SubstLookupRecords  */
 248   HB_Coverage*           Coverage;   /* array of Coverage tables      */
 249   HB_SubstLookupRecord*  SubstLookupRecord;
 250                                       /* array of substitution lookups */
 251 };
 252
 253 typedef struct HB_ContextSubstFormat3_  HB_ContextSubstFormat3;
 254
 255
 256 struct  HB_ContextSubst_
 257 {
 258   HB_UShort  SubstFormat;             /* 1, 2, or 3 */
 259
 260   union
 261   {
 262     HB_ContextSubstFormat1  csf1;
 263     HB_ContextSubstFormat2  csf2;
 264     HB_ContextSubstFormat3  csf3;
 265   } csf;
 266 };
 267
 268 typedef struct HB_ContextSubst_  HB_ContextSubst;
 269
 270
 271 /* LookupType 6 */
 272
 273 struct  HB_ChainSubRule_
 274 {
 275   HB_UShort               BacktrackGlyphCount;
 276                                       /* total number of backtrack glyphs */
 277   HB_UShort*              Backtrack;  /* array of backtrack glyph IDs     */
 278   HB_UShort               InputGlyphCount;
 279                                       /* total number of input glyphs     */
 280   HB_UShort*              Input;      /* array of input glyph IDs         */
 281   HB_UShort               LookaheadGlyphCount;
 282                                       /* total number of lookahead glyphs */
 283   HB_UShort*              Lookahead;  /* array of lookahead glyph IDs     */
 284   HB_UShort               SubstCount; /* number of SubstLookupRecords     */
 285   HB_SubstLookupRecord*  SubstLookupRecord;
 286                                       /* array of SubstLookupRecords      */
 287 };
 288
 289 typedef struct HB_ChainSubRule_  HB_ChainSubRule;
 290
 291
 292 struct  HB_ChainSubRuleSet_
 293 {
 294   HB_UShort          ChainSubRuleCount;
 295                                       /* number of ChainSubRule tables */
 296   HB_ChainSubRule*  ChainSubRule;    /* array of ChainSubRule tables  */
 297 };
 298
 299 typedef struct HB_ChainSubRuleSet_  HB_ChainSubRuleSet;
 300
 301
 302 struct  HB_ChainContextSubstFormat1_
 303 {
 304   HB_Coverage          Coverage;     /* Coverage table                   */
 305   HB_UShort             ChainSubRuleSetCount;
 306                                       /* number of ChainSubRuleSet tables */
 307   HB_ChainSubRuleSet*  ChainSubRuleSet;
 308                                       /* array of ChainSubRuleSet tables  */
 309 };
 310
 311 typedef struct HB_ChainContextSubstFormat1_  HB_ChainContextSubstFormat1;
 312
 313
 314 struct  HB_ChainSubClassRule_
 315 {
 316   HB_UShort               BacktrackGlyphCount;
 317                                       /* total number of backtrack
 318                                          classes                         */
 319   HB_UShort*              Backtrack;  /* array of backtrack classes      */
 320   HB_UShort               InputGlyphCount;
 321                                       /* total number of context classes */
 322   HB_UShort*              Input;      /* array of context classes        */
 323   HB_UShort               LookaheadGlyphCount;
 324                                       /* total number of lookahead
 325                                          classes                         */
 326   HB_UShort*              Lookahead;  /* array of lookahead classes      */
 327   HB_UShort               SubstCount; /* number of SubstLookupRecords    */
 328   HB_SubstLookupRecord*  SubstLookupRecord;
 329                                       /* array of substitution lookups   */
 330 };
 331
 332 typedef struct HB_ChainSubClassRule_  HB_ChainSubClassRule;
 333
 334
 335 struct  HB_ChainSubClassSet_
 336 {
 337   HB_UShort               ChainSubClassRuleCount;
 338                                       /* number of ChainSubClassRule
 339                                          tables                      */
 340   HB_ChainSubClassRule*  ChainSubClassRule;
 341                                       /* array of ChainSubClassRule
 342                                          tables                      */
 343 };
 344
 345 typedef struct HB_ChainSubClassSet_  HB_ChainSubClassSet;
 346
 347
 348 /* The `MaxXXXLength' fields are not defined in the TTO specification
 349    but simplifies the implementation of this format.  It holds the
 350    maximal context length used in the specific context rules.         */
 351
 352 struct  HB_ChainContextSubstFormat2_
 353 {
 354   HB_Coverage           Coverage;    /* Coverage table             */
 355
 356   HB_UShort              MaxBacktrackLength;
 357                                       /* maximal backtrack length   */
 358   HB_ClassDefinition    BacktrackClassDef;
 359                                       /* BacktrackClassDef table    */
 360   HB_UShort              MaxInputLength;
 361                                       /* maximal input length       */
 362   HB_ClassDefinition    InputClassDef;
 363                                       /* InputClassDef table        */
 364   HB_UShort              MaxLookaheadLength;
 365                                       /* maximal lookahead length   */
 366   HB_ClassDefinition    LookaheadClassDef;
 367                                       /* LookaheadClassDef table    */
 368
 369   HB_UShort              ChainSubClassSetCount;
 370                                       /* number of ChainSubClassSet
 371                                          tables                     */
 372   HB_ChainSubClassSet*  ChainSubClassSet;
 373                                       /* array of ChainSubClassSet
 374                                          tables                     */
 375 };
 376
 377 typedef struct HB_ChainContextSubstFormat2_  HB_ChainContextSubstFormat2;
 378
 379
 380 struct  HB_ChainContextSubstFormat3_
 381 {
 382   HB_UShort               BacktrackGlyphCount;
 383                                       /* number of backtrack glyphs    */
 384   HB_Coverage*           BacktrackCoverage;
 385                                       /* array of backtrack Coverage
 386                                          tables                        */
 387   HB_UShort               InputGlyphCount;
 388                                       /* number of input glyphs        */
 389   HB_Coverage*           InputCoverage;
 390                                       /* array of input coverage
 391                                          tables                        */
 392   HB_UShort               LookaheadGlyphCount;
 393                                       /* number of lookahead glyphs    */
 394   HB_Coverage*           LookaheadCoverage;
 395                                       /* array of lookahead coverage
 396                                          tables                        */
 397   HB_UShort               SubstCount; /* number of SubstLookupRecords  */
 398   HB_SubstLookupRecord*  SubstLookupRecord;
 399                                       /* array of substitution lookups */
 400 };
 401
 402 typedef struct HB_ChainContextSubstFormat3_  HB_ChainContextSubstFormat3;
 403
 404
 405 struct  HB_ChainContextSubst_
 406 {
 407   HB_UShort  SubstFormat;             /* 1, 2, or 3 */
 408
 409   union
 410   {
 411     HB_ChainContextSubstFormat1  ccsf1;
 412     HB_ChainContextSubstFormat2  ccsf2;
 413     HB_ChainContextSubstFormat3  ccsf3;
 414   } ccsf;
 415 };
 416
 417 typedef struct HB_ChainContextSubst_  HB_ChainContextSubst;
 418
 419
 420 #if 0
 421 /* LookupType 7 */
 422 struct HB_ExtensionSubst_
 423 {
 424   HB_UShort      SubstFormat;         /* always 1 */
 425   HB_UShort      LookuptType;         /* lookup-type of referenced subtable */
 426   HB_GSUB_SubTable *subtable;         /* referenced subtable */
 427 };
 428
 429 typedef struct HB_ExtensionSubst_  HB_ExtensionSubst;
 430 #endif
 431
 432
 433 /* LookupType 8 */
 434 struct HB_ReverseChainContextSubst_
 435 {
 436   HB_UShort      SubstFormat;         /* always 1 */
 437   HB_Coverage   Coverage;               /* coverage table for input glyphs */
 438   HB_UShort      BacktrackGlyphCount; /* number of backtrack glyphs      */
 439   HB_Coverage*  BacktrackCoverage;   /* array of backtrack Coverage
 440                                          tables                          */
 441   HB_UShort      LookaheadGlyphCount; /* number of lookahead glyphs      */
 442   HB_Coverage*  LookaheadCoverage;   /* array of lookahead Coverage
 443                                          tables                          */
 444   HB_UShort      GlyphCount;          /* number of Glyph IDs             */
 445   HB_UShort*     Substitute;          /* array of substitute Glyph ID    */
 446 };
 447
 448 typedef struct HB_ReverseChainContextSubst_  HB_ReverseChainContextSubst;
 449
 450
 451 union  HB_GSUB_SubTable_
 452 {
 453   HB_SingleSubst              single;
 454   HB_MultipleSubst            multiple;
 455   HB_AlternateSubst           alternate;
 456   HB_LigatureSubst            ligature;
 457   HB_ContextSubst             context;
 458   HB_ChainContextSubst        chain;
 459   HB_ReverseChainContextSubst reverse;
 460 };
 461
 462
 463
 464
 465 HB_INTERNAL HB_Error
 466 _HB_GSUB_Load_SubTable( HB_GSUB_SubTable* st,
 467                                   HB_Stream     stream,
 468                                   HB_UShort     lookup_type );
 469
 470 HB_INTERNAL void
 471 _HB_GSUB_Free_SubTable( HB_GSUB_SubTable* st,
 472                               HB_UShort     lookup_type );
 473
 474 HB_END_HEADER
 475
 476 #endif /* HARFBUZZ_GSUB_PRIVATE_H */