Added a new function: AddNewEvent, which only adds an event to the list if it doesn't already exist. Kept the old one as it might me useful to be able to add an event more than once.
/***************************************************************************/
/* */
/* otvgsub.c */
/* */
/* OpenType GSUB table validation (body). */
/* */
/* Copyright 2004, 2005, 2007 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, -1 );
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, GlyphCount );
OTV_LIMIT_CHECK( GlyphCount * 2 );
/* Substitute */
for ( ; GlyphCount > 0; GlyphCount-- )
if ( FT_NEXT_USHORT( p ) >= valid->glyph_count )
FT_INVALID_GLYPH_ID;
}
break;
default:
FT_INVALID_FORMAT;
}
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_FORMAT;
}
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_FORMAT;
}
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_FORMAT;
}
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 ));
switch ( SubstFormat )
{
case 1:
/* no need to check glyph indices/classes used as input for these */
/* context rules since even invalid glyph indices/classes return */
/* meaningful results */
valid->extra1 = valid->lookup_count;
OTV_NEST3( ContextSubstFormat1, SubRuleSet, SubRule );
OTV_RUN( table, valid );
break;
case 2:
/* no need to check glyph indices/classes used as input for these */
/* context rules since even invalid glyph indices/classes return */
/* meaningful results */
OTV_NEST3( ContextSubstFormat2, SubClassSet, SubClassRule );
OTV_RUN( table, valid );
break;
case 3:
OTV_NEST1( ContextSubstFormat3 );
OTV_RUN( table, valid );
break;
default:
FT_INVALID_FORMAT;
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** GSUB LOOKUP TYPE 6 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* sets valid->extra1 (lookup count) */
static void
otv_ChainContextSubst_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt SubstFormat;
OTV_NAME_ENTER( "ChainContextSubst" );
OTV_LIMIT_CHECK( 2 );
SubstFormat = FT_NEXT_USHORT( p );
OTV_TRACE(( " (format %d)\n", SubstFormat ));
switch ( SubstFormat )
{
case 1:
/* no need to check glyph indices/classes used as input for these */
/* context rules since even invalid glyph indices/classes return */
/* meaningful results */
valid->extra1 = valid->lookup_count;
OTV_NEST3( ChainContextSubstFormat1,
ChainSubRuleSet, ChainSubRule );
OTV_RUN( table, valid );
break;
case 2:
/* no need to check glyph indices/classes used as input for these */
/* context rules since even invalid glyph indices/classes return */
/* meaningful results */
OTV_NEST3( ChainContextSubstFormat2,
ChainSubClassSet, ChainSubClassRule );
OTV_RUN( table, valid );
break;
case 3:
OTV_NEST1( ChainContextSubstFormat3 );
OTV_RUN( table, valid );
break;
default:
FT_INVALID_FORMAT;
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** GSUB LOOKUP TYPE 7 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* uses valid->type_funcs */
static void
otv_ExtensionSubst_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table;
FT_UInt SubstFormat;
OTV_NAME_ENTER( "ExtensionSubst" );
OTV_LIMIT_CHECK( 2 );
SubstFormat = FT_NEXT_USHORT( p );
OTV_TRACE(( " (format %d)\n", SubstFormat ));
switch ( SubstFormat )
{
case 1: /* ExtensionSubstFormat1 */
{
FT_UInt ExtensionLookupType;
FT_ULong ExtensionOffset;
OTV_Validate_Func validate;
OTV_LIMIT_CHECK( 6 );
ExtensionLookupType = FT_NEXT_USHORT( p );
ExtensionOffset = FT_NEXT_ULONG( p );
if ( ExtensionLookupType == 0 ||
ExtensionLookupType == 7 ||
ExtensionLookupType > 8 )
FT_INVALID_DATA;
validate = valid->type_funcs[ExtensionLookupType - 1];
validate( table + ExtensionOffset, valid );
}
break;
default:
FT_INVALID_FORMAT;
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** GSUB LOOKUP TYPE 8 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* uses valid->glyph_count */
static void
otv_ReverseChainSingleSubst_validate( FT_Bytes table,
OTV_Validator valid )
{
FT_Bytes p = table, Coverage;
FT_UInt SubstFormat;
FT_UInt BacktrackGlyphCount, LookaheadGlyphCount, GlyphCount;
OTV_NAME_ENTER( "ReverseChainSingleSubst" );
OTV_LIMIT_CHECK( 2 );
SubstFormat = FT_NEXT_USHORT( p );
OTV_TRACE(( " (format %d)\n", SubstFormat ));
switch ( SubstFormat )
{
case 1: /* ReverseChainSingleSubstFormat1 */
OTV_LIMIT_CHECK( 4 );
Coverage = table + FT_NEXT_USHORT( p );
BacktrackGlyphCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (BacktrackGlyphCount = %d)\n", BacktrackGlyphCount ));
otv_Coverage_validate( Coverage, valid, -1 );
OTV_LIMIT_CHECK( BacktrackGlyphCount * 2 + 2 );
for ( ; BacktrackGlyphCount > 0; BacktrackGlyphCount-- )
otv_Coverage_validate( table + FT_NEXT_USHORT( p ), valid, -1 );
LookaheadGlyphCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (LookaheadGlyphCount = %d)\n", LookaheadGlyphCount ));
OTV_LIMIT_CHECK( LookaheadGlyphCount * 2 + 2 );
for ( ; LookaheadGlyphCount > 0; LookaheadGlyphCount-- )
otv_Coverage_validate( table + FT_NEXT_USHORT( p ), valid, -1 );
GlyphCount = FT_NEXT_USHORT( p );
OTV_TRACE(( " (GlyphCount = %d)\n", GlyphCount ));
if ( GlyphCount != otv_Coverage_get_count( Coverage ) )
FT_INVALID_DATA;
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_FORMAT;
}
OTV_EXIT;
}
static const OTV_Validate_Func otv_gsub_validate_funcs[8] =
{
otv_SingleSubst_validate,
otv_MultipleSubst_validate,
otv_AlternateSubst_validate,
otv_LigatureSubst_validate,
otv_ContextSubst_validate,
otv_ChainContextSubst_validate,
otv_ExtensionSubst_validate,
otv_ReverseChainSingleSubst_validate
};
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** GSUB TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* sets valid->type_count */
/* sets valid->type_funcs */
/* sets valid->glyph_count */
FT_LOCAL_DEF( void )
otv_GSUB_validate( FT_Bytes table,
FT_UInt glyph_count,
FT_Validator ftvalid )
{
OTV_ValidatorRec validrec;
OTV_Validator valid = &validrec;
FT_Bytes p = table;
FT_UInt ScriptList, FeatureList, LookupList;
valid->root = ftvalid;
FT_TRACE3(( "validating GSUB table\n" ));
OTV_INIT;
OTV_LIMIT_CHECK( 10 );
if ( FT_NEXT_ULONG( p ) != 0x10000UL ) /* Version */
FT_INVALID_FORMAT;
ScriptList = FT_NEXT_USHORT( p );
FeatureList = FT_NEXT_USHORT( p );
LookupList = FT_NEXT_USHORT( p );
valid->type_count = 8;
valid->type_funcs = (OTV_Validate_Func*)otv_gsub_validate_funcs;
valid->glyph_count = glyph_count;
otv_LookupList_validate( table + LookupList,
valid );
otv_FeatureList_validate( table + FeatureList, table + LookupList,
valid );
otv_ScriptList_validate( table + ScriptList, table + FeatureList,
valid );
FT_TRACE4(( "\n" ));
}
/* END */