/***************************************************************************//*                                                                         *//*  otvgsub.c                                                              *//*                                                                         *//*    OpenType GSUB table validation (body).                               *//*                                                                         *//*  Copyright 2004, 2005 by                                                *//*  David Turner, Robert Wilhelm, and Werner Lemberg.                      *//*                                                                         *//*  This file is part of the FreeType project, and may only be used,       *//*  modified, and distributed under the terms of the FreeType project      *//*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     *//*  this file you indicate that you have read the license and              *//*  understand and accept it fully.                                        *//*                                                                         *//***************************************************************************/#include "otvalid.h"#include "otvcommn.h"  /*************************************************************************/  /*                                                                       */  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */  /* messages during execution.                                            */  /*                                                                       */#undef  FT_COMPONENT#define FT_COMPONENT  trace_otvgsub  /*************************************************************************/  /*************************************************************************/  /*****                                                               *****/  /*****                  GSUB LOOKUP TYPE 1                           *****/  /*****                                                               *****/  /*************************************************************************/  /*************************************************************************/  /* uses valid->glyph_count */  static void  otv_SingleSubst_validate( FT_Bytes       table,                            OTV_Validator  valid )  {    FT_Bytes  p = table;    FT_UInt   SubstFormat;    OTV_NAME_ENTER( "SingleSubst" );    OTV_LIMIT_CHECK( 2 );    SubstFormat = FT_NEXT_USHORT( p );    OTV_TRACE(( " (format %d)\n", SubstFormat ));    switch ( SubstFormat )    {    case 1:     /* SingleSubstFormat1 */      {        FT_Bytes  Coverage;        FT_Int    DeltaGlyphID;        FT_Long   idx;        OTV_LIMIT_CHECK( 4 );        Coverage     = table + FT_NEXT_USHORT( p );        DeltaGlyphID = FT_NEXT_SHORT( p );        otv_Coverage_validate( Coverage, valid );        idx = otv_Coverage_get_first( Coverage ) + DeltaGlyphID;        if ( idx < 0 )          FT_INVALID_DATA;        idx = otv_Coverage_get_last( Coverage ) + DeltaGlyphID;        if ( (FT_UInt)idx >= valid->glyph_count )          FT_INVALID_DATA;      }      break;    case 2:     /* SingleSubstFormat2 */      {        FT_UInt  Coverage, GlyphCount;        OTV_LIMIT_CHECK( 4 );        Coverage   = FT_NEXT_USHORT( p );        GlyphCount = FT_NEXT_USHORT( p );        OTV_TRACE(( " (GlyphCount = %d)\n", GlyphCount ));        otv_Coverage_validate( table + Coverage, valid );        OTV_LIMIT_CHECK( GlyphCount * 2 );        /* Substitute */        for ( ; GlyphCount > 0; GlyphCount-- )          if ( FT_NEXT_USHORT( p ) >= valid->glyph_count )            FT_INVALID_DATA;      }      break;    default:      FT_INVALID_DATA;    }    OTV_EXIT;  }  /*************************************************************************/  /*************************************************************************/  /*****                                                               *****/  /*****                  GSUB LOOKUP TYPE 2                           *****/  /*****                                                               *****/  /*************************************************************************/  /*************************************************************************/  /* sets valid->extra1 (glyph count) */  static void  otv_MultipleSubst_validate( FT_Bytes       table,                              OTV_Validator  valid )  {    FT_Bytes  p = table;    FT_UInt   SubstFormat;    OTV_NAME_ENTER( "MultipleSubst" );    OTV_LIMIT_CHECK( 2 );    SubstFormat = FT_NEXT_USHORT( p );    OTV_TRACE(( " (format %d)\n", SubstFormat ));    switch ( SubstFormat )    {    case 1:      valid->extra1 = valid->glyph_count;      OTV_NEST2( MultipleSubstFormat1, Sequence );      OTV_RUN( table, valid );      break;    default:      FT_INVALID_DATA;    }    OTV_EXIT;  }  /*************************************************************************/  /*************************************************************************/  /*****                                                               *****/  /*****                    GSUB LOOKUP TYPE 3                         *****/  /*****                                                               *****/  /*************************************************************************/  /*************************************************************************/  /* sets valid->extra1 (glyph count) */  static void  otv_AlternateSubst_validate( FT_Bytes       table,                               OTV_Validator  valid )  {    FT_Bytes  p = table;    FT_UInt   SubstFormat;    OTV_NAME_ENTER( "AlternateSubst" );    OTV_LIMIT_CHECK( 2 );    SubstFormat = FT_NEXT_USHORT( p );    OTV_TRACE(( " (format %d)\n", SubstFormat ));    switch ( SubstFormat )    {    case 1:      valid->extra1 = valid->glyph_count;      OTV_NEST2( AlternateSubstFormat1, AlternateSet );      OTV_RUN( table, valid );      break;    default:      FT_INVALID_DATA;    }    OTV_EXIT;  }  /*************************************************************************/  /*************************************************************************/  /*****                                                               *****/  /*****                    GSUB LOOKUP TYPE 4                         *****/  /*****                                                               *****/  /*************************************************************************/  /*************************************************************************/#define LigatureFunc  otv_Ligature_validate  /* uses valid->glyph_count */  static void  otv_Ligature_validate( FT_Bytes       table,                         OTV_Validator  valid )  {    FT_Bytes  p = table;    FT_UInt   LigatureGlyph, CompCount;    OTV_ENTER;    OTV_LIMIT_CHECK( 4 );    LigatureGlyph = FT_NEXT_USHORT( p );    if ( LigatureGlyph >= valid->glyph_count )      FT_INVALID_DATA;    CompCount = FT_NEXT_USHORT( p );    OTV_TRACE(( " (CompCount = %d)\n", CompCount ));    if ( CompCount == 0 )      FT_INVALID_DATA;    CompCount--;    OTV_LIMIT_CHECK( CompCount * 2 );     /* Component */    /* no need to check the Component glyph indices */    OTV_EXIT;  }  static void  otv_LigatureSubst_validate( FT_Bytes       table,                              OTV_Validator  valid )  {    FT_Bytes  p = table;    FT_UInt   SubstFormat;    OTV_NAME_ENTER( "LigatureSubst" );    OTV_LIMIT_CHECK( 2 );    SubstFormat = FT_NEXT_USHORT( p );    OTV_TRACE(( " (format %d)\n", SubstFormat ));    switch ( SubstFormat )    {    case 1:      OTV_NEST3( LigatureSubstFormat1, LigatureSet, Ligature );      OTV_RUN( table, valid );      break;    default:      FT_INVALID_DATA;    }    OTV_EXIT;  }  /*************************************************************************/  /*************************************************************************/  /*****                                                               *****/  /*****                  GSUB LOOKUP TYPE 5                           *****/  /*****                                                               *****/  /*************************************************************************/  /*************************************************************************/  /* sets valid->extra1 (lookup count) */  static void  otv_ContextSubst_validate( FT_Bytes       table,                             OTV_Validator  valid )  {    FT_Bytes  p = table;    FT_UInt   SubstFormat;    OTV_NAME_ENTER( "ContextSubst" );    OTV_LIMIT_CHECK( 2 );    SubstFormat = FT_NEXT_USHORT( p );    OTV_TRACE(( " (format %d)\n", SubstFormat ));