src/third_party/skia/third_party/harfbuzz/src/harfbuzz-gpos-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_GPOS_PRIVATE_H
  27 #define HARFBUZZ_GPOS_PRIVATE_H
  28
  29 #include "harfbuzz-impl.h"
  30 #include "harfbuzz-stream-private.h"
  31 #include "harfbuzz-gpos.h"
  32
  33 HB_BEGIN_HEADER
  34
  35
  36 /* shared tables */
  37
  38 struct  HB_ValueRecord_
  39 {
  40   HB_Short    XPlacement;             /* horizontal adjustment for
  41                                          placement                      */
  42   HB_Short    YPlacement;             /* vertical adjustment for
  43                                          placement                      */
  44   HB_Short    XAdvance;               /* horizontal adjustment for
  45                                          advance                        */
  46   HB_Short    YAdvance;               /* vertical adjustment for
  47                                          advance                        */
  48   HB_Device  XPlacementDevice;       /* device table for horizontal
  49                                          placement                      */
  50   HB_Device  YPlacementDevice;       /* device table for vertical
  51                                          placement                      */
  52   HB_Device  XAdvanceDevice;         /* device table for horizontal
  53                                          advance                        */
  54   HB_Device  YAdvanceDevice;         /* device table for vertical
  55                                          advance                        */
  56   HB_UShort   XIdPlacement;           /* horizontal placement metric ID */
  57   HB_UShort   YIdPlacement;           /* vertical placement metric ID   */
  58   HB_UShort   XIdAdvance;             /* horizontal advance metric ID   */
  59   HB_UShort   YIdAdvance;             /* vertical advance metric ID     */
  60 };
  61
  62 typedef struct HB_ValueRecord_  HB_ValueRecord;
  63
  64
  65 /* Mask values to scan the value format of the ValueRecord structure.
  66  We always expand compressed ValueRecords of the font.              */
  67
  68 #define HB_GPOS_FORMAT_HAVE_X_PLACEMENT         0x0001
  69 #define HB_GPOS_FORMAT_HAVE_Y_PLACEMENT         0x0002
  70 #define HB_GPOS_FORMAT_HAVE_X_ADVANCE           0x0004
  71 #define HB_GPOS_FORMAT_HAVE_Y_ADVANCE           0x0008
  72 #define HB_GPOS_FORMAT_HAVE_X_PLACEMENT_DEVICE  0x0010
  73 #define HB_GPOS_FORMAT_HAVE_Y_PLACEMENT_DEVICE  0x0020
  74 #define HB_GPOS_FORMAT_HAVE_X_ADVANCE_DEVICE    0x0040
  75 #define HB_GPOS_FORMAT_HAVE_Y_ADVANCE_DEVICE    0x0080
  76 #define HB_GPOS_FORMAT_HAVE_X_ID_PLACEMENT      0x0100
  77 #define HB_GPOS_FORMAT_HAVE_Y_ID_PLACEMENT      0x0200
  78 #define HB_GPOS_FORMAT_HAVE_X_ID_ADVANCE        0x0400
  79 #define HB_GPOS_FORMAT_HAVE_Y_ID_ADVANCE        0x0800
  80
  81
  82 struct  HB_AnchorFormat1_
  83 {
  84   HB_Short   XCoordinate;             /* horizontal value */
  85   HB_Short   YCoordinate;             /* vertical value   */
  86 };
  87
  88 typedef struct HB_AnchorFormat1_  HB_AnchorFormat1;
  89
  90
  91 struct  HB_AnchorFormat2_
  92 {
  93   HB_Short   XCoordinate;             /* horizontal value             */
  94   HB_Short   YCoordinate;             /* vertical value               */
  95   HB_UShort  AnchorPoint;             /* index to glyph contour point */
  96 };
  97
  98 typedef struct HB_AnchorFormat2_  HB_AnchorFormat2;
  99
 100
 101 struct  HB_AnchorFormat3_
 102 {
 103   HB_Short    XCoordinate;            /* horizontal value              */
 104   HB_Short    YCoordinate;            /* vertical value                */
 105   HB_Device  XDeviceTable;           /* device table for X coordinate */
 106   HB_Device  YDeviceTable;           /* device table for Y coordinate */
 107 };
 108
 109 typedef struct HB_AnchorFormat3_  HB_AnchorFormat3;
 110
 111
 112 struct  HB_AnchorFormat4_
 113 {
 114   HB_UShort  XIdAnchor;               /* horizontal metric ID */
 115   HB_UShort  YIdAnchor;               /* vertical metric ID   */
 116 };
 117
 118 typedef struct HB_AnchorFormat4_  HB_AnchorFormat4;
 119
 120
 121 struct  HB_Anchor_
 122 {
 123   HB_UShort  PosFormat;               /* 1, 2, 3, or 4 -- 0 indicates
 124                                          that there is no Anchor table */
 125
 126   union
 127   {
 128     HB_AnchorFormat1  af1;
 129     HB_AnchorFormat2  af2;
 130     HB_AnchorFormat3  af3;
 131     HB_AnchorFormat4  af4;
 132   } af;
 133 };
 134
 135 typedef struct HB_Anchor_  HB_Anchor;
 136
 137
 138 struct  HB_MarkRecord_
 139 {
 140   HB_UShort   Class;                  /* mark class   */
 141   HB_Anchor  MarkAnchor;             /* anchor table */
 142 };
 143
 144 typedef struct HB_MarkRecord_  HB_MarkRecord;
 145
 146
 147 struct  HB_MarkArray_
 148 {
 149   HB_UShort        MarkCount;         /* number of MarkRecord tables */
 150   HB_MarkRecord*  MarkRecord;        /* array of MarkRecord tables  */
 151 };
 152
 153 typedef struct HB_MarkArray_  HB_MarkArray;
 154
 155
 156 /* LookupType 1 */
 157
 158 struct  HB_SinglePosFormat1_
 159 {
 160   HB_ValueRecord  Value;             /* ValueRecord for all covered
 161                                          glyphs                      */
 162 };
 163
 164 typedef struct HB_SinglePosFormat1_  HB_SinglePosFormat1;
 165
 166
 167 struct  HB_SinglePosFormat2_
 168 {
 169   HB_UShort         ValueCount;       /* number of ValueRecord tables */
 170   HB_ValueRecord*  Value;            /* array of ValueRecord tables  */
 171 };
 172
 173 typedef struct HB_SinglePosFormat2_  HB_SinglePosFormat2;
 174
 175
 176 struct  HB_SinglePos_
 177 {
 178   HB_UShort     PosFormat;            /* 1 or 2         */
 179   HB_Coverage  Coverage;             /* Coverage table */
 180
 181   HB_UShort     ValueFormat;          /* format of ValueRecord table */
 182
 183   union
 184   {
 185     HB_SinglePosFormat1  spf1;
 186     HB_SinglePosFormat2  spf2;
 187   } spf;
 188 };
 189
 190 typedef struct HB_SinglePos_  HB_SinglePos;
 191
 192
 193 /* LookupType 2 */
 194
 195 struct  HB_PairValueRecord_
 196 {
 197   HB_UShort        SecondGlyph;       /* glyph ID for second glyph  */
 198   HB_ValueRecord  Value1;            /* pos. data for first glyph  */
 199   HB_ValueRecord  Value2;            /* pos. data for second glyph */
 200 };
 201
 202 typedef struct HB_PairValueRecord_  HB_PairValueRecord;
 203
 204
 205 struct  HB_PairSet_
 206 {
 207   HB_UShort             PairValueCount;
 208                                       /* number of PairValueRecord tables */
 209   HB_PairValueRecord*  PairValueRecord;
 210                                       /* array of PairValueRecord tables  */
 211 };
 212
 213 typedef struct HB_PairSet_  HB_PairSet;
 214
 215
 216 struct  HB_PairPosFormat1_
 217 {
 218   HB_UShort     PairSetCount;         /* number of PairSet tables    */
 219   HB_PairSet*  PairSet;              /* array of PairSet tables     */
 220 };
 221
 222 typedef struct HB_PairPosFormat1_  HB_PairPosFormat1;
 223
 224
 225 struct  HB_Class2Record_
 226 {
 227   HB_ValueRecord  Value1;            /* pos. data for first glyph  */
 228   HB_ValueRecord  Value2;            /* pos. data for second glyph */
 229 };
 230
 231 typedef struct HB_Class2Record_  HB_Class2Record;
 232
 233
 234 struct  HB_Class1Record_
 235 {
 236   HB_Class2Record*  Class2Record;    /* array of Class2Record tables */
 237 };
 238
 239 typedef struct HB_Class1Record_  HB_Class1Record;
 240
 241
 242 struct  HB_PairPosFormat2_
 243 {
 244   HB_ClassDefinition  ClassDef1;     /* class def. for first glyph     */
 245   HB_ClassDefinition  ClassDef2;     /* class def. for second glyph    */
 246   HB_UShort            Class1Count;   /* number of classes in ClassDef1
 247                                          table                          */
 248   HB_UShort            Class2Count;   /* number of classes in ClassDef2
 249                                          table                          */
 250   HB_Class1Record*    Class1Record;  /* array of Class1Record tables   */
 251 };
 252
 253 typedef struct HB_PairPosFormat2_  HB_PairPosFormat2;
 254
 255
 256 struct  HB_PairPos_
 257 {
 258   HB_UShort     PosFormat;            /* 1 or 2         */
 259   HB_Coverage  Coverage;             /* Coverage table */
 260   HB_UShort     ValueFormat1;         /* format of ValueRecord table
 261                                          for first glyph             */
 262   HB_UShort     ValueFormat2;         /* format of ValueRecord table
 263                                          for second glyph            */
 264
 265   union
 266   {
 267     HB_PairPosFormat1  ppf1;
 268     HB_PairPosFormat2  ppf2;
 269   } ppf;
 270 };
 271
 272 typedef struct HB_PairPos_  HB_PairPos;
 273
 274
 275 /* LookupType 3 */
 276
 277 struct  HB_EntryExitRecord_
 278 {
 279   HB_Anchor  EntryAnchor;            /* entry Anchor table */
 280   HB_Anchor  ExitAnchor;             /* exit Anchor table  */
 281 };
 282
 283
 284 typedef struct HB_EntryExitRecord_  HB_EntryExitRecord;
 285
 286 struct  HB_CursivePos_
 287 {
 288   HB_UShort             PosFormat;    /* always 1                         */
 289   HB_Coverage          Coverage;     /* Coverage table                   */
 290   HB_UShort             EntryExitCount;
 291                                       /* number of EntryExitRecord tables */
 292   HB_EntryExitRecord*  EntryExitRecord;
 293                                       /* array of EntryExitRecord tables  */
 294 };
 295
 296 typedef struct HB_CursivePos_  HB_CursivePos;
 297
 298
 299 /* LookupType 4 */
 300
 301 struct  HB_BaseRecord_
 302 {
 303   HB_Anchor*  BaseAnchor;            /* array of base glyph anchor
 304                                          tables                     */
 305 };
 306
 307 typedef struct HB_BaseRecord_  HB_BaseRecord;
 308
 309
 310 struct  HB_BaseArray_
 311 {
 312   HB_UShort        BaseCount;         /* number of BaseRecord tables */
 313   HB_BaseRecord*  BaseRecord;        /* array of BaseRecord tables  */
 314 };
 315
 316 typedef struct HB_BaseArray_  HB_BaseArray;
 317
 318
 319 struct  HB_MarkBasePos_
 320 {
 321   HB_UShort      PosFormat;           /* always 1                  */
 322   HB_Coverage   MarkCoverage;        /* mark glyph coverage table */
 323   HB_Coverage   BaseCoverage;        /* base glyph coverage table */
 324   HB_UShort      ClassCount;          /* number of mark classes    */
 325   HB_MarkArray  MarkArray;           /* mark array table          */
 326   HB_BaseArray  BaseArray;           /* base array table          */
 327 };
 328
 329 typedef struct HB_MarkBasePos_  HB_MarkBasePos;
 330
 331
 332 /* LookupType 5 */
 333
 334 struct  HB_ComponentRecord_
 335 {
 336   HB_Anchor*  LigatureAnchor;        /* array of ligature glyph anchor
 337                                          tables                         */
 338 };
 339
 340 typedef struct HB_ComponentRecord_  HB_ComponentRecord;
 341
 342
 343 struct  HB_LigatureAttach_
 344 {
 345   HB_UShort             ComponentCount;
 346                                       /* number of ComponentRecord tables */
 347   HB_ComponentRecord*  ComponentRecord;
 348                                       /* array of ComponentRecord tables  */
 349 };
 350
 351 typedef struct HB_LigatureAttach_  HB_LigatureAttach;
 352
 353
 354 struct  HB_LigatureArray_
 355 {
 356   HB_UShort            LigatureCount; /* number of LigatureAttach tables */
 357   HB_LigatureAttach*  LigatureAttach;
 358                                       /* array of LigatureAttach tables  */
 359 };
 360
 361 typedef struct HB_LigatureArray_  HB_LigatureArray;
 362
 363
 364 struct  HB_MarkLigPos_
 365 {
 366   HB_UShort          PosFormat;       /* always 1                      */
 367   HB_Coverage       MarkCoverage;    /* mark glyph coverage table     */
 368   HB_Coverage       LigatureCoverage;
 369                                       /* ligature glyph coverage table */
 370   HB_UShort          ClassCount;      /* number of mark classes        */
 371   HB_MarkArray      MarkArray;       /* mark array table              */
 372   HB_LigatureArray  LigatureArray;   /* ligature array table          */
 373 };
 374
 375 typedef struct HB_MarkLigPos_  HB_MarkLigPos;
 376
 377
 378 /* LookupType 6 */
 379
 380 struct  HB_Mark2Record_
 381 {
 382   HB_Anchor*  Mark2Anchor;           /* array of mark glyph anchor
 383                                          tables                     */
 384 };
 385
 386 typedef struct HB_Mark2Record_  HB_Mark2Record;
 387
 388
 389 struct  HB_Mark2Array_
 390 {
 391   HB_UShort         Mark2Count;       /* number of Mark2Record tables */
 392   HB_Mark2Record*  Mark2Record;      /* array of Mark2Record tables  */
 393 };
 394
 395 typedef struct HB_Mark2Array_  HB_Mark2Array;
 396
 397
 398 struct  HB_MarkMarkPos_
 399 {
 400   HB_UShort       PosFormat;          /* always 1                         */
 401   HB_Coverage    Mark1Coverage;      /* first mark glyph coverage table  */
 402   HB_Coverage    Mark2Coverage;      /* second mark glyph coverave table */
 403   HB_UShort       ClassCount;         /* number of combining mark classes */
 404   HB_MarkArray   Mark1Array;         /* MarkArray table for first mark   */
 405   HB_Mark2Array  Mark2Array;         /* MarkArray table for second mark  */
 406 };
 407
 408 typedef struct HB_MarkMarkPos_  HB_MarkMarkPos;
 409
 410
 411 /* needed by both lookup type 7 and 8 */
 412
 413 struct  HB_PosLookupRecord_
 414 {
 415   HB_UShort  SequenceIndex;           /* index into current
 416                                          glyph sequence               */
 417   HB_UShort  LookupListIndex;         /* Lookup to apply to that pos. */
 418 };
 419
 420 typedef struct HB_PosLookupRecord_  HB_PosLookupRecord;
 421
 422
 423 /* LookupType 7 */
 424
 425 struct  HB_PosRule_
 426 {
 427   HB_UShort             GlyphCount;   /* total number of input glyphs     */
 428   HB_UShort             PosCount;     /* number of PosLookupRecord tables */
 429   HB_UShort*            Input;        /* array of input glyph IDs         */
 430   HB_PosLookupRecord*  PosLookupRecord;
 431                                       /* array of PosLookupRecord tables  */
 432 };
 433
 434 typedef struct HB_PosRule_  HB_PosRule;
 435
 436
 437 struct  HB_PosRuleSet_
 438 {
 439   HB_UShort     PosRuleCount;         /* number of PosRule tables */
 440   HB_PosRule*  PosRule;              /* array of PosRule tables  */
 441 };
 442
 443 typedef struct HB_PosRuleSet_  HB_PosRuleSet;
 444
 445
 446 struct  HB_ContextPosFormat1_
 447 {
 448   HB_Coverage     Coverage;          /* Coverage table              */
 449   HB_UShort        PosRuleSetCount;   /* number of PosRuleSet tables */
 450   HB_PosRuleSet*  PosRuleSet;        /* array of PosRuleSet tables  */
 451 };
 452
 453 typedef struct HB_ContextPosFormat1_  HB_ContextPosFormat1;
 454
 455
 456 struct  HB_PosClassRule_
 457 {
 458   HB_UShort             GlyphCount;   /* total number of context classes  */
 459   HB_UShort             PosCount;     /* number of PosLookupRecord tables */
 460   HB_UShort*            Class;        /* array of classes                 */
 461   HB_PosLookupRecord*  PosLookupRecord;
 462                                       /* array of PosLookupRecord tables  */
 463 };
 464
 465 typedef struct HB_PosClassRule_  HB_PosClassRule;
 466
 467
 468 struct  HB_PosClassSet_
 469 {
 470   HB_UShort          PosClassRuleCount;
 471                                       /* number of PosClassRule tables */
 472   HB_PosClassRule*  PosClassRule;    /* array of PosClassRule tables  */
 473 };
 474
 475 typedef struct HB_PosClassSet_  HB_PosClassSet;
 476
 477
 478 /* The `MaxContextLength' field is not defined in the TTO specification
 479    but simplifies the implementation of this format.  It holds the
 480    maximal context length used in the context rules.                    */
 481
 482 struct  HB_ContextPosFormat2_
 483 {
 484   HB_UShort            MaxContextLength;
 485                                       /* maximal context length       */
 486   HB_Coverage         Coverage;      /* Coverage table               */
 487   HB_ClassDefinition  ClassDef;      /* ClassDef table               */
 488   HB_UShort            PosClassSetCount;
 489                                       /* number of PosClassSet tables */
 490   HB_PosClassSet*     PosClassSet;   /* array of PosClassSet tables  */
 491 };
 492
 493 typedef struct HB_ContextPosFormat2_  HB_ContextPosFormat2;
 494
 495
 496 struct  HB_ContextPosFormat3_
 497 {
 498   HB_UShort             GlyphCount;   /* number of input glyphs           */
 499   HB_UShort             PosCount;     /* number of PosLookupRecord tables */
 500   HB_Coverage*         Coverage;     /* array of Coverage tables         */
 501   HB_PosLookupRecord*  PosLookupRecord;
 502                                       /* array of PosLookupRecord tables  */
 503 };
 504
 505 typedef struct HB_ContextPosFormat3_  HB_ContextPosFormat3;
 506
 507
 508 struct  HB_ContextPos_
 509 {
 510   HB_UShort  PosFormat;               /* 1, 2, or 3     */
 511
 512   union
 513   {
 514     HB_ContextPosFormat1  cpf1;
 515     HB_ContextPosFormat2  cpf2;
 516     HB_ContextPosFormat3  cpf3;
 517   } cpf;
 518 };
 519
 520 typedef struct HB_ContextPos_  HB_ContextPos;
 521
 522
 523 /* LookupType 8 */
 524
 525 struct  HB_ChainPosRule_
 526 {
 527   HB_UShort             BacktrackGlyphCount;
 528                                       /* total number of backtrack glyphs */
 529   HB_UShort*            Backtrack;    /* array of backtrack glyph IDs     */
 530   HB_UShort             InputGlyphCount;
 531                                       /* total number of input glyphs     */
 532   HB_UShort*            Input;        /* array of input glyph IDs         */
 533   HB_UShort             LookaheadGlyphCount;
 534                                       /* total number of lookahead glyphs */
 535   HB_UShort*            Lookahead;    /* array of lookahead glyph IDs     */
 536   HB_UShort             PosCount;     /* number of PosLookupRecords       */
 537   HB_PosLookupRecord*  PosLookupRecord;
 538                                       /* array of PosLookupRecords       */
 539 };
 540
 541 typedef struct HB_ChainPosRule_  HB_ChainPosRule;
 542
 543
 544 struct  HB_ChainPosRuleSet_
 545 {
 546   HB_UShort          ChainPosRuleCount;
 547                                       /* number of ChainPosRule tables */
 548   HB_ChainPosRule*  ChainPosRule;    /* array of ChainPosRule tables  */
 549 };
 550
 551 typedef struct HB_ChainPosRuleSet_  HB_ChainPosRuleSet;
 552
 553
 554 struct  HB_ChainContextPosFormat1_
 555 {
 556   HB_Coverage          Coverage;     /* Coverage table                   */
 557   HB_UShort             ChainPosRuleSetCount;
 558                                       /* number of ChainPosRuleSet tables */
 559   HB_ChainPosRuleSet*  ChainPosRuleSet;
 560                                       /* array of ChainPosRuleSet tables  */
 561 };
 562
 563 typedef struct HB_ChainContextPosFormat1_  HB_ChainContextPosFormat1;
 564
 565
 566 struct  HB_ChainPosClassRule_
 567 {
 568   HB_UShort             BacktrackGlyphCount;
 569                                       /* total number of backtrack
 570                                          classes                         */
 571   HB_UShort*            Backtrack;    /* array of backtrack classes      */
 572   HB_UShort             InputGlyphCount;
 573                                       /* total number of context classes */
 574   HB_UShort*            Input;        /* array of context classes        */
 575   HB_UShort             LookaheadGlyphCount;
 576                                       /* total number of lookahead
 577                                          classes                         */
 578   HB_UShort*            Lookahead;    /* array of lookahead classes      */
 579   HB_UShort             PosCount;     /* number of PosLookupRecords      */
 580   HB_PosLookupRecord*  PosLookupRecord;
 581                                       /* array of substitution lookups   */
 582 };
 583
 584 typedef struct HB_ChainPosClassRule_  HB_ChainPosClassRule;
 585
 586
 587 struct  HB_ChainPosClassSet_
 588 {
 589   HB_UShort               ChainPosClassRuleCount;
 590                                       /* number of ChainPosClassRule
 591                                          tables                      */
 592   HB_ChainPosClassRule*  ChainPosClassRule;
 593                                       /* array of ChainPosClassRule
 594                                          tables                      */
 595 };
 596
 597 typedef struct HB_ChainPosClassSet_  HB_ChainPosClassSet;
 598
 599
 600 /* The `MaxXXXLength' fields are not defined in the TTO specification
 601    but simplifies the implementation of this format.  It holds the
 602    maximal context length used in the specific context rules.         */
 603
 604 struct  HB_ChainContextPosFormat2_
 605 {
 606   HB_Coverage           Coverage;    /* Coverage table             */
 607
 608   HB_UShort              MaxBacktrackLength;
 609                                       /* maximal backtrack length   */
 610   HB_ClassDefinition    BacktrackClassDef;
 611                                       /* BacktrackClassDef table    */
 612   HB_UShort              MaxInputLength;
 613                                       /* maximal input length       */
 614   HB_ClassDefinition    InputClassDef;
 615                                       /* InputClassDef table        */
 616   HB_UShort              MaxLookaheadLength;
 617                                       /* maximal lookahead length   */
 618   HB_ClassDefinition    LookaheadClassDef;
 619                                       /* LookaheadClassDef table    */
 620
 621   HB_UShort              ChainPosClassSetCount;
 622                                       /* number of ChainPosClassSet
 623                                          tables                     */
 624   HB_ChainPosClassSet*  ChainPosClassSet;
 625                                       /* array of ChainPosClassSet
 626                                          tables                     */
 627 };
 628
 629 typedef struct HB_ChainContextPosFormat2_  HB_ChainContextPosFormat2;
 630
 631
 632 struct  HB_ChainContextPosFormat3_
 633 {
 634   HB_UShort             BacktrackGlyphCount;
 635                                       /* number of backtrack glyphs    */
 636   HB_Coverage*         BacktrackCoverage;
 637                                       /* array of backtrack Coverage
 638                                          tables                        */
 639   HB_UShort             InputGlyphCount;
 640                                       /* number of input glyphs        */
 641   HB_Coverage*         InputCoverage;
 642                                       /* array of input coverage
 643                                          tables                        */
 644   HB_UShort             LookaheadGlyphCount;
 645                                       /* number of lookahead glyphs    */
 646   HB_Coverage*         LookaheadCoverage;
 647                                       /* array of lookahead coverage
 648                                          tables                        */
 649   HB_UShort             PosCount;     /* number of PosLookupRecords    */
 650   HB_PosLookupRecord*  PosLookupRecord;
 651                                       /* array of substitution lookups */
 652 };
 653
 654 typedef struct HB_ChainContextPosFormat3_  HB_ChainContextPosFormat3;
 655
 656
 657 struct  HB_ChainContextPos_
 658 {
 659   HB_UShort  PosFormat;             /* 1, 2, or 3 */
 660
 661   union
 662   {
 663     HB_ChainContextPosFormat1  ccpf1;
 664     HB_ChainContextPosFormat2  ccpf2;
 665     HB_ChainContextPosFormat3  ccpf3;
 666   } ccpf;
 667 };
 668
 669 typedef struct HB_ChainContextPos_  HB_ChainContextPos;
 670
 671
 672 #if 0
 673 /* LookupType 10 */
 674 struct HB_ExtensionPos_
 675 {
 676   HB_UShort      PosFormat;           /* always 1 */
 677   HB_UShort      LookuptType;         /* lookup-type of referenced subtable */
 678   HB_GPOS_SubTable *subtable;         /* referenced subtable */
 679 };
 680
 681 typedef struct HB_ExtensionPos_  HB_ExtensionPos;
 682 #endif
 683
 684
 685 union  HB_GPOS_SubTable_
 686 {
 687   HB_SinglePos        single;
 688   HB_PairPos          pair;
 689   HB_CursivePos       cursive;
 690   HB_MarkBasePos      markbase;
 691   HB_MarkLigPos       marklig;
 692   HB_MarkMarkPos      markmark;
 693   HB_ContextPos       context;
 694   HB_ChainContextPos  chain;
 695 };
 696
 697 typedef union HB_GPOS_SubTable_  HB_GPOS_SubTable;
 698
 699
 700
 701 HB_INTERNAL HB_Error
 702 _HB_GPOS_Load_SubTable( HB_GPOS_SubTable* st,
 703                                   HB_Stream     stream,
 704                                   HB_UShort     lookup_type );
 705
 706 HB_INTERNAL void
 707 _HB_GPOS_Free_SubTable( HB_GPOS_SubTable* st,
 708                               HB_UShort     lookup_type );
 709
 710 HB_END_HEADER
 711
 712 #endif /* HARFBUZZ_GPOS_PRIVATE_H */