third_party/harfbuzz/src/harfbuzz-gsub-private.h - platform/external/skia - Gitiles

 /*
  * Copyright (C) 1998-2004  David Turner and Werner Lemberg
  * Copyright (C) 2006  Behdad Esfahbod
  *
  * This is part of HarfBuzz, an OpenType Layout engine library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
  * all copies of this software.
  *
  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  *
  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  */

 #ifndef HARFBUZZ_GSUB_PRIVATE_H
 #define HARFBUZZ_GSUB_PRIVATE_H

 #include "harfbuzz-impl.h"
 #include "harfbuzz-stream-private.h"
 #include "harfbuzz-gsub.h"

 HB_BEGIN_HEADER


 typedef union HB_GSUB_SubTable_  HB_GSUB_SubTable;

 /* LookupType 1 */

 struct  HB_SingleSubstFormat1_
 {
   HB_Short  DeltaGlyphID;             /* constant added to get
 					 substitution glyph index */
 };

 typedef struct HB_SingleSubstFormat1_  HB_SingleSubstFormat1;


 struct  HB_SingleSubstFormat2_
 {
   HB_UShort   GlyphCount;             /* number of glyph IDs in
 					 Substitute array              */
   HB_UShort*  Substitute;             /* array of substitute glyph IDs */
 };

 typedef struct HB_SingleSubstFormat2_  HB_SingleSubstFormat2;


 struct  HB_SingleSubst_
 {
   HB_UShort     SubstFormat;          /* 1 or 2         */
   HB_Coverage  Coverage;             /* Coverage table */

   union
   {
     HB_SingleSubstFormat1  ssf1;
     HB_SingleSubstFormat2  ssf2;
   } ssf;
 };

 typedef struct HB_SingleSubst_  HB_SingleSubst;


 /* LookupType 2 */

 struct  HB_Sequence_
 {
   HB_UShort   GlyphCount;             /* number of glyph IDs in the
 					 Substitute array           */
   HB_UShort*  Substitute;             /* string of glyph IDs to
 					 substitute                 */
 };

 typedef struct HB_Sequence_  HB_Sequence;


 struct  HB_MultipleSubst_
 {
   HB_UShort      SubstFormat;         /* always 1                  */
   HB_Coverage   Coverage;            /* Coverage table            */
   HB_UShort      SequenceCount;       /* number of Sequence tables */
   HB_Sequence*  Sequence;            /* array of Sequence tables  */
 };

 typedef struct HB_MultipleSubst_  HB_MultipleSubst;


 /* LookupType 3 */

 struct  HB_AlternateSet_
 {
   HB_UShort   GlyphCount;             /* number of glyph IDs in the
 					 Alternate array              */
   HB_UShort*  Alternate;              /* array of alternate glyph IDs */
 };

 typedef struct HB_AlternateSet_  HB_AlternateSet;


 struct  HB_AlternateSubst_
 {
   HB_UShort          SubstFormat;     /* always 1                      */
   HB_Coverage       Coverage;        /* Coverage table                */
   HB_UShort          AlternateSetCount;
 				      /* number of AlternateSet tables */
   HB_AlternateSet*  AlternateSet;    /* array of AlternateSet tables  */
 };

 typedef struct HB_AlternateSubst_  HB_AlternateSubst;


 /* LookupType 4 */

 struct  HB_Ligature_
 {
   HB_UShort   LigGlyph;               /* glyphID of ligature
 					 to substitute                    */
   HB_UShort   ComponentCount;         /* number of components in ligature */
   HB_UShort*  Component;              /* array of component glyph IDs     */
 };

 typedef struct HB_Ligature_  HB_Ligature;


 struct  HB_LigatureSet_
 {
   HB_UShort      LigatureCount;       /* number of Ligature tables */
   HB_Ligature*  Ligature;            /* array of Ligature tables  */
 };

 typedef struct HB_LigatureSet_  HB_LigatureSet;


 struct  HB_LigatureSubst_
 {
   HB_UShort         SubstFormat;      /* always 1                     */
   HB_Coverage      Coverage;         /* Coverage table               */
   HB_UShort         LigatureSetCount; /* number of LigatureSet tables */
   HB_LigatureSet*  LigatureSet;      /* array of LigatureSet tables  */
 };

 typedef struct HB_LigatureSubst_  HB_LigatureSubst;


 /* needed by both lookup type 5 and 6 */

 struct  HB_SubstLookupRecord_
 {
   HB_UShort  SequenceIndex;           /* index into current
 					 glyph sequence               */
   HB_UShort  LookupListIndex;         /* Lookup to apply to that pos. */
 };

 typedef struct HB_SubstLookupRecord_  HB_SubstLookupRecord;


 /* LookupType 5 */

 struct  HB_SubRule_
 {
   HB_UShort               GlyphCount; /* total number of input glyphs */
   HB_UShort               SubstCount; /* number of SubstLookupRecord
 					 tables                       */
   HB_UShort*              Input;      /* array of input glyph IDs     */
   HB_SubstLookupRecord*  SubstLookupRecord;
 				      /* array of SubstLookupRecord
 					 tables                       */
 };

 typedef struct HB_SubRule_  HB_SubRule;


 struct  HB_SubRuleSet_
 {
   HB_UShort     SubRuleCount;         /* number of SubRule tables */
   HB_SubRule*  SubRule;              /* array of SubRule tables  */
 };

 typedef struct HB_SubRuleSet_  HB_SubRuleSet;


 struct  HB_ContextSubstFormat1_
 {
   HB_Coverage     Coverage;          /* Coverage table              */
   HB_UShort        SubRuleSetCount;   /* number of SubRuleSet tables */
   HB_SubRuleSet*  SubRuleSet;        /* array of SubRuleSet tables  */
 };

 typedef struct HB_ContextSubstFormat1_  HB_ContextSubstFormat1;


 struct  HB_SubClassRule_
 {
   HB_UShort               GlyphCount; /* total number of context classes */
   HB_UShort               SubstCount; /* number of SubstLookupRecord
 					 tables                          */
   HB_UShort*              Class;      /* array of classes                */
   HB_SubstLookupRecord*  SubstLookupRecord;
 				      /* array of SubstLookupRecord
 					 tables                          */
 };

 typedef struct HB_SubClassRule_  HB_SubClassRule;


 struct  HB_SubClassSet_
 {
   HB_UShort          SubClassRuleCount;
 				      /* number of SubClassRule tables */
   HB_SubClassRule*  SubClassRule;    /* array of SubClassRule tables  */
 };

 typedef struct HB_SubClassSet_  HB_SubClassSet;


 /* The `MaxContextLength' field is not defined in the TTO specification
    but simplifies the implementation of this format.  It holds the
    maximal context length used in the context rules.                    */

 struct  HB_ContextSubstFormat2_
 {
   HB_UShort            MaxContextLength;
 				      /* maximal context length       */
   HB_Coverage         Coverage;      /* Coverage table               */
   HB_ClassDefinition  ClassDef;      /* ClassDef table               */
   HB_UShort            SubClassSetCount;
 				      /* number of SubClassSet tables */
   HB_SubClassSet*     SubClassSet;   /* array of SubClassSet tables  */
 };

 typedef struct HB_ContextSubstFormat2_  HB_ContextSubstFormat2;


 struct  HB_ContextSubstFormat3_
 {
   HB_UShort               GlyphCount; /* number of input glyphs        */
   HB_UShort               SubstCount; /* number of SubstLookupRecords  */
   HB_Coverage*           Coverage;   /* array of Coverage tables      */
   HB_SubstLookupRecord*  SubstLookupRecord;
 				      /* array of substitution lookups */
 };

 typedef struct HB_ContextSubstFormat3_  HB_ContextSubstFormat3;


 struct  HB_ContextSubst_
 {
   HB_UShort  SubstFormat;             /* 1, 2, or 3 */

   union
   {
     HB_ContextSubstFormat1  csf1;
     HB_ContextSubstFormat2  csf2;
     HB_ContextSubstFormat3  csf3;
   } csf;
 };

 typedef struct HB_ContextSubst_  HB_ContextSubst;


 /* LookupType 6 */

 struct  HB_ChainSubRule_
 {
   HB_UShort               BacktrackGlyphCount;
 				      /* total number of backtrack glyphs */
   HB_UShort*              Backtrack;  /* array of backtrack glyph IDs     */
   HB_UShort               InputGlyphCount;
 				      /* total number of input glyphs     */
   HB_UShort*              Input;      /* array of input glyph IDs         */
   HB_UShort               LookaheadGlyphCount;
 				      /* total number of lookahead glyphs */
   HB_UShort*              Lookahead;  /* array of lookahead glyph IDs     */
   HB_UShort               SubstCount; /* number of SubstLookupRecords     */
   HB_SubstLookupRecord*  SubstLookupRecord;
 				      /* array of SubstLookupRecords      */
 };

 typedef struct HB_ChainSubRule_  HB_ChainSubRule;


 struct  HB_ChainSubRuleSet_
 {
   HB_UShort          ChainSubRuleCount;
 				      /* number of ChainSubRule tables */
   HB_ChainSubRule*  ChainSubRule;    /* array of ChainSubRule tables  */
 };

 typedef struct HB_ChainSubRuleSet_  HB_ChainSubRuleSet;


 struct  HB_ChainContextSubstFormat1_
 {
   HB_Coverage          Coverage;     /* Coverage table                   */
   HB_UShort             ChainSubRuleSetCount;
 				      /* number of ChainSubRuleSet tables */
   HB_ChainSubRuleSet*  ChainSubRuleSet;
 				      /* array of ChainSubRuleSet tables  */
 };

 typedef struct HB_ChainContextSubstFormat1_  HB_ChainContextSubstFormat1;


 struct  HB_ChainSubClassRule_
 {
   HB_UShort               BacktrackGlyphCount;
 				      /* total number of backtrack
 					 classes                         */
   HB_UShort*              Backtrack;  /* array of backtrack classes      */
   HB_UShort               InputGlyphCount;
 				      /* total number of context classes */
   HB_UShort*              Input;      /* array of context classes        */
   HB_UShort               LookaheadGlyphCount;
 				      /* total number of lookahead
 					 classes                         */
   HB_UShort*              Lookahead;  /* array of lookahead classes      */
   HB_UShort               SubstCount; /* number of SubstLookupRecords    */
   HB_SubstLookupRecord*  SubstLookupRecord;
 				      /* array of substitution lookups   */
 };

 typedef struct HB_ChainSubClassRule_  HB_ChainSubClassRule;


 struct  HB_ChainSubClassSet_
 {
   HB_UShort               ChainSubClassRuleCount;
 				      /* number of ChainSubClassRule
 					 tables                      */
   HB_ChainSubClassRule*  ChainSubClassRule;
 				      /* array of ChainSubClassRule
 					 tables                      */
 };

 typedef struct HB_ChainSubClassSet_  HB_ChainSubClassSet;


 /* The `MaxXXXLength' fields are not defined in the TTO specification
    but simplifies the implementation of this format.  It holds the
    maximal context length used in the specific context rules.         */

 struct  HB_ChainContextSubstFormat2_
 {
   HB_Coverage           Coverage;    /* Coverage table             */

   HB_UShort              MaxBacktrackLength;
 				      /* maximal backtrack length   */
   HB_ClassDefinition    BacktrackClassDef;
 				      /* BacktrackClassDef table    */
   HB_UShort              MaxInputLength;
 				      /* maximal input length       */
   HB_ClassDefinition    InputClassDef;
 				      /* InputClassDef table        */
   HB_UShort              MaxLookaheadLength;
 				      /* maximal lookahead length   */
   HB_ClassDefinition    LookaheadClassDef;
 				      /* LookaheadClassDef table    */

   HB_UShort              ChainSubClassSetCount;
 				      /* number of ChainSubClassSet
 					 tables                     */
   HB_ChainSubClassSet*  ChainSubClassSet;
 				      /* array of ChainSubClassSet
 					 tables                     */
 };

 typedef struct HB_ChainContextSubstFormat2_  HB_ChainContextSubstFormat2;


 struct  HB_ChainContextSubstFormat3_
 {
   HB_UShort               BacktrackGlyphCount;
 				      /* number of backtrack glyphs    */
   HB_Coverage*           BacktrackCoverage;
 				      /* array of backtrack Coverage
 					 tables                        */
   HB_UShort               InputGlyphCount;
 				      /* number of input glyphs        */
   HB_Coverage*           InputCoverage;
 				      /* array of input coverage
 					 tables                        */
   HB_UShort               LookaheadGlyphCount;
 				      /* number of lookahead glyphs    */
   HB_Coverage*           LookaheadCoverage;
 				      /* array of lookahead coverage
 					 tables                        */
   HB_UShort               SubstCount; /* number of SubstLookupRecords  */
   HB_SubstLookupRecord*  SubstLookupRecord;
 				      /* array of substitution lookups */
 };

 typedef struct HB_ChainContextSubstFormat3_  HB_ChainContextSubstFormat3;


 struct  HB_ChainContextSubst_
 {
   HB_UShort  SubstFormat;             /* 1, 2, or 3 */

   union
   {
     HB_ChainContextSubstFormat1  ccsf1;
     HB_ChainContextSubstFormat2  ccsf2;
     HB_ChainContextSubstFormat3  ccsf3;
   } ccsf;
 };

 typedef struct HB_ChainContextSubst_  HB_ChainContextSubst;


 #if 0
 /* LookupType 7 */
 struct HB_ExtensionSubst_
 {
   HB_UShort      SubstFormat;         /* always 1 */
   HB_UShort      LookuptType;         /* lookup-type of referenced subtable */
   HB_GSUB_SubTable *subtable;         /* referenced subtable */
 };

 typedef struct HB_ExtensionSubst_  HB_ExtensionSubst;
 #endif


 /* LookupType 8 */
 struct HB_ReverseChainContextSubst_
 {
   HB_UShort      SubstFormat;         /* always 1 */
   HB_Coverage   Coverage;	        /* coverage table for input glyphs */
   HB_UShort      BacktrackGlyphCount; /* number of backtrack glyphs      */
   HB_Coverage*  BacktrackCoverage;   /* array of backtrack Coverage
 					 tables                          */
   HB_UShort      LookaheadGlyphCount; /* number of lookahead glyphs      */
   HB_Coverage*  LookaheadCoverage;   /* array of lookahead Coverage
 					 tables                          */
   HB_UShort      GlyphCount;          /* number of Glyph IDs             */
   HB_UShort*     Substitute;          /* array of substitute Glyph ID    */
 };

 typedef struct HB_ReverseChainContextSubst_  HB_ReverseChainContextSubst;


 union  HB_GSUB_SubTable_
 {
   HB_SingleSubst              single;
   HB_MultipleSubst            multiple;
   HB_AlternateSubst           alternate;
   HB_LigatureSubst            ligature;
   HB_ContextSubst             context;
   HB_ChainContextSubst        chain;
   HB_ReverseChainContextSubst reverse;
 };


 HB_INTERNAL HB_Error
 _HB_GSUB_Load_SubTable( HB_GSUB_SubTable* st,
 				  HB_Stream     stream,
 				  HB_UShort     lookup_type );

 HB_INTERNAL void
 _HB_GSUB_Free_SubTable( HB_GSUB_SubTable* st,
 			      HB_UShort     lookup_type );

 HB_END_HEADER

 #endif /* HARFBUZZ_GSUB_PRIVATE_H */
	/*
	* Copyright (C) 1998-2004 David Turner and Werner Lemberg
	* Copyright (C) 2006 Behdad Esfahbod
	*
	* This is part of HarfBuzz, an OpenType Layout engine library.
	*
	* Permission is hereby granted, without written agreement and without
	* license or royalty fees, to use, copy, modify, and distribute this
	* software and its documentation for any purpose, provided that the
	* above copyright notice and the following two paragraphs appear in
	* all copies of this software.
	*
	* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
	* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
	* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
	* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
	* DAMAGE.
	*
	* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
	* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
	* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
	* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
	* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
	*/

	#ifndef HARFBUZZ_GSUB_PRIVATE_H
	#define HARFBUZZ_GSUB_PRIVATE_H

	#include "harfbuzz-impl.h"
	#include "harfbuzz-stream-private.h"
	#include "harfbuzz-gsub.h"

	HB_BEGIN_HEADER


	typedef union HB_GSUB_SubTable_ HB_GSUB_SubTable;

	/* LookupType 1 */

	struct HB_SingleSubstFormat1_
	{
	HB_Short DeltaGlyphID; /* constant added to get
	substitution glyph index */
	};

	typedef struct HB_SingleSubstFormat1_ HB_SingleSubstFormat1;


	struct HB_SingleSubstFormat2_
	{
	HB_UShort GlyphCount; /* number of glyph IDs in
	Substitute array */
	HB_UShort* Substitute; /* array of substitute glyph IDs */
	};

	typedef struct HB_SingleSubstFormat2_ HB_SingleSubstFormat2;


	struct HB_SingleSubst_
	{
	HB_UShort SubstFormat; /* 1 or 2 */
	HB_Coverage Coverage; /* Coverage table */

	union
	{
	HB_SingleSubstFormat1 ssf1;
	HB_SingleSubstFormat2 ssf2;
	} ssf;
	};

	typedef struct HB_SingleSubst_ HB_SingleSubst;


	/* LookupType 2 */

	struct HB_Sequence_
	{
	HB_UShort GlyphCount; /* number of glyph IDs in the
	Substitute array */
	HB_UShort* Substitute; /* string of glyph IDs to
	substitute */
	};

	typedef struct HB_Sequence_ HB_Sequence;


	struct HB_MultipleSubst_
	{
	HB_UShort SubstFormat; /* always 1 */
	HB_Coverage Coverage; /* Coverage table */
	HB_UShort SequenceCount; /* number of Sequence tables */
	HB_Sequence* Sequence; /* array of Sequence tables */
	};

	typedef struct HB_MultipleSubst_ HB_MultipleSubst;


	/* LookupType 3 */

	struct HB_AlternateSet_
	{
	HB_UShort GlyphCount; /* number of glyph IDs in the
	Alternate array */
	HB_UShort* Alternate; /* array of alternate glyph IDs */
	};

	typedef struct HB_AlternateSet_ HB_AlternateSet;


	struct HB_AlternateSubst_
	{
	HB_UShort SubstFormat; /* always 1 */
	HB_Coverage Coverage; /* Coverage table */
	HB_UShort AlternateSetCount;
	/* number of AlternateSet tables */
	HB_AlternateSet* AlternateSet; /* array of AlternateSet tables */
	};

	typedef struct HB_AlternateSubst_ HB_AlternateSubst;


	/* LookupType 4 */

	struct HB_Ligature_
	{
	HB_UShort LigGlyph; /* glyphID of ligature
	to substitute */
	HB_UShort ComponentCount; /* number of components in ligature */
	HB_UShort* Component; /* array of component glyph IDs */
	};

	typedef struct HB_Ligature_ HB_Ligature;


	struct HB_LigatureSet_
	{
	HB_UShort LigatureCount; /* number of Ligature tables */
	HB_Ligature* Ligature; /* array of Ligature tables */
	};

	typedef struct HB_LigatureSet_ HB_LigatureSet;


	struct HB_LigatureSubst_
	{
	HB_UShort SubstFormat; /* always 1 */
	HB_Coverage Coverage; /* Coverage table */
	HB_UShort LigatureSetCount; /* number of LigatureSet tables */
	HB_LigatureSet* LigatureSet; /* array of LigatureSet tables */
	};

	typedef struct HB_LigatureSubst_ HB_LigatureSubst;


	/* needed by both lookup type 5 and 6 */

	struct HB_SubstLookupRecord_
	{
	HB_UShort SequenceIndex; /* index into current
	glyph sequence */
	HB_UShort LookupListIndex; /* Lookup to apply to that pos. */
	};

	typedef struct HB_SubstLookupRecord_ HB_SubstLookupRecord;


	/* LookupType 5 */

	struct HB_SubRule_
	{
	HB_UShort GlyphCount; /* total number of input glyphs */
	HB_UShort SubstCount; /* number of SubstLookupRecord
	tables */
	HB_UShort* Input; /* array of input glyph IDs */
	HB_SubstLookupRecord* SubstLookupRecord;
	/* array of SubstLookupRecord
	tables */
	};

	typedef struct HB_SubRule_ HB_SubRule;


	struct HB_SubRuleSet_
	{
	HB_UShort SubRuleCount; /* number of SubRule tables */
	HB_SubRule* SubRule; /* array of SubRule tables */
	};

	typedef struct HB_SubRuleSet_ HB_SubRuleSet;


	struct HB_ContextSubstFormat1_
	{
	HB_Coverage Coverage; /* Coverage table */
	HB_UShort SubRuleSetCount; /* number of SubRuleSet tables */
	HB_SubRuleSet* SubRuleSet; /* array of SubRuleSet tables */
	};

	typedef struct HB_ContextSubstFormat1_ HB_ContextSubstFormat1;


	struct HB_SubClassRule_
	{
	HB_UShort GlyphCount; /* total number of context classes */
	HB_UShort SubstCount; /* number of SubstLookupRecord
	tables */
	HB_UShort* Class; /* array of classes */
	HB_SubstLookupRecord* SubstLookupRecord;
	/* array of SubstLookupRecord
	tables */
	};

	typedef struct HB_SubClassRule_ HB_SubClassRule;


	struct HB_SubClassSet_
	{
	HB_UShort SubClassRuleCount;
	/* number of SubClassRule tables */
	HB_SubClassRule* SubClassRule; /* array of SubClassRule tables */
	};

	typedef struct HB_SubClassSet_ HB_SubClassSet;


	/* The `MaxContextLength' field is not defined in the TTO specification
	but simplifies the implementation of this format. It holds the
	maximal context length used in the context rules. */

	struct HB_ContextSubstFormat2_
	{
	HB_UShort MaxContextLength;
	/* maximal context length */
	HB_Coverage Coverage; /* Coverage table */
	HB_ClassDefinition ClassDef; /* ClassDef table */
	HB_UShort SubClassSetCount;
	/* number of SubClassSet tables */
	HB_SubClassSet* SubClassSet; /* array of SubClassSet tables */
	};

	typedef struct HB_ContextSubstFormat2_ HB_ContextSubstFormat2;


	struct HB_ContextSubstFormat3_
	{
	HB_UShort GlyphCount; /* number of input glyphs */
	HB_UShort SubstCount; /* number of SubstLookupRecords */
	HB_Coverage* Coverage; /* array of Coverage tables */
	HB_SubstLookupRecord* SubstLookupRecord;
	/* array of substitution lookups */
	};

	typedef struct HB_ContextSubstFormat3_ HB_ContextSubstFormat3;


	struct HB_ContextSubst_
	{
	HB_UShort SubstFormat; /* 1, 2, or 3 */

	union
	{
	HB_ContextSubstFormat1 csf1;
	HB_ContextSubstFormat2 csf2;
	HB_ContextSubstFormat3 csf3;
	} csf;
	};

	typedef struct HB_ContextSubst_ HB_ContextSubst;


	/* LookupType 6 */

	struct HB_ChainSubRule_
	{
	HB_UShort BacktrackGlyphCount;
	/* total number of backtrack glyphs */
	HB_UShort* Backtrack; /* array of backtrack glyph IDs */
	HB_UShort InputGlyphCount;
	/* total number of input glyphs */
	HB_UShort* Input; /* array of input glyph IDs */
	HB_UShort LookaheadGlyphCount;
	/* total number of lookahead glyphs */
	HB_UShort* Lookahead; /* array of lookahead glyph IDs */
	HB_UShort SubstCount; /* number of SubstLookupRecords */
	HB_SubstLookupRecord* SubstLookupRecord;
	/* array of SubstLookupRecords */
	};

	typedef struct HB_ChainSubRule_ HB_ChainSubRule;


	struct HB_ChainSubRuleSet_
	{
	HB_UShort ChainSubRuleCount;
	/* number of ChainSubRule tables */
	HB_ChainSubRule* ChainSubRule; /* array of ChainSubRule tables */
	};

	typedef struct HB_ChainSubRuleSet_ HB_ChainSubRuleSet;


	struct HB_ChainContextSubstFormat1_
	{
	HB_Coverage Coverage; /* Coverage table */
	HB_UShort ChainSubRuleSetCount;
	/* number of ChainSubRuleSet tables */
	HB_ChainSubRuleSet* ChainSubRuleSet;
	/* array of ChainSubRuleSet tables */
	};

	typedef struct HB_ChainContextSubstFormat1_ HB_ChainContextSubstFormat1;


	struct HB_ChainSubClassRule_
	{
	HB_UShort BacktrackGlyphCount;
	/* total number of backtrack
	classes */
	HB_UShort* Backtrack; /* array of backtrack classes */
	HB_UShort InputGlyphCount;
	/* total number of context classes */
	HB_UShort* Input; /* array of context classes */
	HB_UShort LookaheadGlyphCount;
	/* total number of lookahead
	classes */
	HB_UShort* Lookahead; /* array of lookahead classes */
	HB_UShort SubstCount; /* number of SubstLookupRecords */
	HB_SubstLookupRecord* SubstLookupRecord;
	/* array of substitution lookups */
	};

	typedef struct HB_ChainSubClassRule_ HB_ChainSubClassRule;


	struct HB_ChainSubClassSet_
	{
	HB_UShort ChainSubClassRuleCount;
	/* number of ChainSubClassRule
	tables */
	HB_ChainSubClassRule* ChainSubClassRule;
	/* array of ChainSubClassRule
	tables */
	};

	typedef struct HB_ChainSubClassSet_ HB_ChainSubClassSet;


	/* The `MaxXXXLength' fields are not defined in the TTO specification
	but simplifies the implementation of this format. It holds the
	maximal context length used in the specific context rules. */

	struct HB_ChainContextSubstFormat2_
	{
	HB_Coverage Coverage; /* Coverage table */

	HB_UShort MaxBacktrackLength;
	/* maximal backtrack length */
	HB_ClassDefinition BacktrackClassDef;
	/* BacktrackClassDef table */
	HB_UShort MaxInputLength;
	/* maximal input length */
	HB_ClassDefinition InputClassDef;
	/* InputClassDef table */
	HB_UShort MaxLookaheadLength;
	/* maximal lookahead length */
	HB_ClassDefinition LookaheadClassDef;
	/* LookaheadClassDef table */

	HB_UShort ChainSubClassSetCount;
	/* number of ChainSubClassSet
	tables */
	HB_ChainSubClassSet* ChainSubClassSet;
	/* array of ChainSubClassSet
	tables */
	};

	typedef struct HB_ChainContextSubstFormat2_ HB_ChainContextSubstFormat2;


	struct HB_ChainContextSubstFormat3_
	{
	HB_UShort BacktrackGlyphCount;
	/* number of backtrack glyphs */
	HB_Coverage* BacktrackCoverage;
	/* array of backtrack Coverage
	tables */
	HB_UShort InputGlyphCount;
	/* number of input glyphs */
	HB_Coverage* InputCoverage;
	/* array of input coverage
	tables */
	HB_UShort LookaheadGlyphCount;
	/* number of lookahead glyphs */
	HB_Coverage* LookaheadCoverage;
	/* array of lookahead coverage
	tables */
	HB_UShort SubstCount; /* number of SubstLookupRecords */
	HB_SubstLookupRecord* SubstLookupRecord;
	/* array of substitution lookups */
	};

	typedef struct HB_ChainContextSubstFormat3_ HB_ChainContextSubstFormat3;


	struct HB_ChainContextSubst_
	{
	HB_UShort SubstFormat; /* 1, 2, or 3 */

	union
	{
	HB_ChainContextSubstFormat1 ccsf1;
	HB_ChainContextSubstFormat2 ccsf2;
	HB_ChainContextSubstFormat3 ccsf3;
	} ccsf;
	};

	typedef struct HB_ChainContextSubst_ HB_ChainContextSubst;


	#if 0
	/* LookupType 7 */
	struct HB_ExtensionSubst_
	{
	HB_UShort SubstFormat; /* always 1 */
	HB_UShort LookuptType; /* lookup-type of referenced subtable */
	HB_GSUB_SubTable subtable; / referenced subtable */
	};

	typedef struct HB_ExtensionSubst_ HB_ExtensionSubst;
	#endif


	/* LookupType 8 */
	struct HB_ReverseChainContextSubst_
	{
	HB_UShort SubstFormat; /* always 1 */
	HB_Coverage Coverage; /* coverage table for input glyphs */
	HB_UShort BacktrackGlyphCount; /* number of backtrack glyphs */
	HB_Coverage* BacktrackCoverage; /* array of backtrack Coverage
	tables */
	HB_UShort LookaheadGlyphCount; /* number of lookahead glyphs */
	HB_Coverage* LookaheadCoverage; /* array of lookahead Coverage
	tables */
	HB_UShort GlyphCount; /* number of Glyph IDs */
	HB_UShort* Substitute; /* array of substitute Glyph ID */
	};

	typedef struct HB_ReverseChainContextSubst_ HB_ReverseChainContextSubst;


	union HB_GSUB_SubTable_
	{
	HB_SingleSubst single;
	HB_MultipleSubst multiple;
	HB_AlternateSubst alternate;
	HB_LigatureSubst ligature;
	HB_ContextSubst context;
	HB_ChainContextSubst chain;
	HB_ReverseChainContextSubst reverse;
	};




	HB_INTERNAL HB_Error
	_HB_GSUB_Load_SubTable( HB_GSUB_SubTable* st,
	HB_Stream stream,
	HB_UShort lookup_type );

	HB_INTERNAL void
	_HB_GSUB_Free_SubTable( HB_GSUB_SubTable* st,
	HB_UShort lookup_type );

	HB_END_HEADER

	#endif /* HARFBUZZ_GSUB_PRIVATE_H */