ref: 03ceda9701cd8c08ea5b4ee0c2d558a98fc4ed7d
dir: /src/otvalid/otvmath.c/
/****************************************************************************
*
* otvmath.c
*
* OpenType MATH table validation (body).
*
* Copyright (C) 2007-2020 by
* David Turner, Robert Wilhelm, and Werner Lemberg.
*
* Written by George Williams.
*
* 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"
#include "otvgpos.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 otvmath
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** MATH TYPOGRAPHIC CONSTANTS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
otv_MathConstants_validate( FT_Bytes table,
OTV_Validator otvalid )
{
FT_Bytes p = table;
FT_UInt i;
FT_UInt table_size;
OTV_OPTIONAL_TABLE( DeviceTableOffset );
OTV_NAME_ENTER( "MathConstants" );
/* 56 constants, 51 have device tables */
OTV_LIMIT_CHECK( 2 * ( 56 + 51 ) );
table_size = 2 * ( 56 + 51 );
p += 4 * 2; /* First 4 constants have no device tables */
for ( i = 0; i < 51; i++ )
{
p += 2; /* skip the value */
OTV_OPTIONAL_OFFSET( DeviceTableOffset );
OTV_SIZE_CHECK( DeviceTableOffset );
if ( DeviceTableOffset )
otv_Device_validate( table + DeviceTableOffset, otvalid );
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** MATH ITALICS CORRECTION *****/
/***** MATH TOP ACCENT ATTACHMENT *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
otv_MathItalicsCorrectionInfo_validate( FT_Bytes table,
OTV_Validator otvalid,
FT_Int isItalic )
{
FT_Bytes p = table;
FT_UInt i, cnt, table_size;
OTV_OPTIONAL_TABLE( Coverage );
OTV_OPTIONAL_TABLE( DeviceTableOffset );
FT_UNUSED( isItalic ); /* only used if tracing is active */
OTV_NAME_ENTER( isItalic ? "MathItalicsCorrectionInfo"
: "MathTopAccentAttachment" );
OTV_LIMIT_CHECK( 4 );
OTV_OPTIONAL_OFFSET( Coverage );
cnt = FT_NEXT_USHORT( p );
OTV_LIMIT_CHECK( 4 * cnt );
table_size = 4 + 4 * cnt;
OTV_SIZE_CHECK( Coverage );
otv_Coverage_validate( table + Coverage, otvalid, (FT_Int)cnt );
for ( i = 0; i < cnt; i++ )
{
p += 2; /* Skip the value */
OTV_OPTIONAL_OFFSET( DeviceTableOffset );
OTV_SIZE_CHECK( DeviceTableOffset );
if ( DeviceTableOffset )
otv_Device_validate( table + DeviceTableOffset, otvalid );
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** MATH KERNING *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
otv_MathKern_validate( FT_Bytes table,
OTV_Validator otvalid )
{
FT_Bytes p = table;
FT_UInt i, cnt, table_size;
OTV_OPTIONAL_TABLE( DeviceTableOffset );
/* OTV_NAME_ENTER( "MathKern" );*/
OTV_LIMIT_CHECK( 2 );
cnt = FT_NEXT_USHORT( p );
OTV_LIMIT_CHECK( 4 * cnt + 2 );
table_size = 4 + 4 * cnt;
/* Heights */
for ( i = 0; i < cnt; i++ )
{
p += 2; /* Skip the value */
OTV_OPTIONAL_OFFSET( DeviceTableOffset );
OTV_SIZE_CHECK( DeviceTableOffset );
if ( DeviceTableOffset )
otv_Device_validate( table + DeviceTableOffset, otvalid );
}
/* One more Kerning value */
for ( i = 0; i < cnt + 1; i++ )
{
p += 2; /* Skip the value */
OTV_OPTIONAL_OFFSET( DeviceTableOffset );
OTV_SIZE_CHECK( DeviceTableOffset );
if ( DeviceTableOffset )
otv_Device_validate( table + DeviceTableOffset, otvalid );
}
OTV_EXIT;
}
static void
otv_MathKernInfo_validate( FT_Bytes table,
OTV_Validator otvalid )
{
FT_Bytes p = table;
FT_UInt i, j, cnt, table_size;
OTV_OPTIONAL_TABLE( Coverage );
OTV_OPTIONAL_TABLE( MKRecordOffset );
OTV_NAME_ENTER( "MathKernInfo" );
OTV_LIMIT_CHECK( 4 );
OTV_OPTIONAL_OFFSET( Coverage );
cnt = FT_NEXT_USHORT( p );
OTV_LIMIT_CHECK( 8 * cnt );
table_size = 4 + 8 * cnt;
OTV_SIZE_CHECK( Coverage );
otv_Coverage_validate( table + Coverage, otvalid, (FT_Int)cnt );
for ( i = 0; i < cnt; i++ )
{
for ( j = 0; j < 4; j++ )
{
OTV_OPTIONAL_OFFSET( MKRecordOffset );
OTV_SIZE_CHECK( MKRecordOffset );
if ( MKRecordOffset )
otv_MathKern_validate( table + MKRecordOffset, otvalid );
}
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** MATH GLYPH INFO *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
otv_MathGlyphInfo_validate( FT_Bytes table,
OTV_Validator otvalid )
{
FT_Bytes p = table;
FT_UInt MathItalicsCorrectionInfo, MathTopAccentAttachment;
FT_UInt ExtendedShapeCoverage, MathKernInfo;
OTV_NAME_ENTER( "MathGlyphInfo" );
OTV_LIMIT_CHECK( 8 );
MathItalicsCorrectionInfo = FT_NEXT_USHORT( p );
MathTopAccentAttachment = FT_NEXT_USHORT( p );
ExtendedShapeCoverage = FT_NEXT_USHORT( p );
MathKernInfo = FT_NEXT_USHORT( p );
if ( MathItalicsCorrectionInfo )
otv_MathItalicsCorrectionInfo_validate(
table + MathItalicsCorrectionInfo, otvalid, TRUE );
/* Italic correction and Top Accent Attachment have the same format */
if ( MathTopAccentAttachment )
otv_MathItalicsCorrectionInfo_validate(
table + MathTopAccentAttachment, otvalid, FALSE );
if ( ExtendedShapeCoverage )
{
OTV_NAME_ENTER( "ExtendedShapeCoverage" );
otv_Coverage_validate( table + ExtendedShapeCoverage, otvalid, -1 );
OTV_EXIT;
}
if ( MathKernInfo )
otv_MathKernInfo_validate( table + MathKernInfo, otvalid );
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** MATH GLYPH CONSTRUCTION *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
otv_GlyphAssembly_validate( FT_Bytes table,
OTV_Validator otvalid )
{
FT_Bytes p = table;
FT_UInt pcnt, table_size;
FT_UInt i;
OTV_OPTIONAL_TABLE( DeviceTableOffset );
/* OTV_NAME_ENTER( "GlyphAssembly" ); */
OTV_LIMIT_CHECK( 6 );
p += 2; /* Skip the Italics Correction value */
OTV_OPTIONAL_OFFSET( DeviceTableOffset );
pcnt = FT_NEXT_USHORT( p );
OTV_LIMIT_CHECK( 8 * pcnt );
table_size = 6 + 8 * pcnt;
OTV_SIZE_CHECK( DeviceTableOffset );
if ( DeviceTableOffset )
otv_Device_validate( table + DeviceTableOffset, otvalid );
for ( i = 0; i < pcnt; i++ )
{
FT_UInt gid;
gid = FT_NEXT_USHORT( p );
if ( gid >= otvalid->glyph_count )
FT_INVALID_GLYPH_ID;
p += 2*4; /* skip the Start, End, Full, and Flags fields */
}
/* OTV_EXIT; */
}
static void
otv_MathGlyphConstruction_validate( FT_Bytes table,
OTV_Validator otvalid )
{
FT_Bytes p = table;
FT_UInt vcnt, table_size;
FT_UInt i;
OTV_OPTIONAL_TABLE( GlyphAssembly );
/* OTV_NAME_ENTER( "MathGlyphConstruction" ); */
OTV_LIMIT_CHECK( 4 );
OTV_OPTIONAL_OFFSET( GlyphAssembly );
vcnt = FT_NEXT_USHORT( p );
OTV_LIMIT_CHECK( 4 * vcnt );
table_size = 4 + 4 * vcnt;
for ( i = 0; i < vcnt; i++ )
{
FT_UInt gid;
gid = FT_NEXT_USHORT( p );
if ( gid >= otvalid->glyph_count )
FT_INVALID_GLYPH_ID;
p += 2; /* skip the size */
}
OTV_SIZE_CHECK( GlyphAssembly );
if ( GlyphAssembly )
otv_GlyphAssembly_validate( table+GlyphAssembly, otvalid );
/* OTV_EXIT; */
}
static void
otv_MathVariants_validate( FT_Bytes table,
OTV_Validator otvalid )
{
FT_Bytes p = table;
FT_UInt vcnt, hcnt, i, table_size;
OTV_OPTIONAL_TABLE( VCoverage );
OTV_OPTIONAL_TABLE( HCoverage );
OTV_OPTIONAL_TABLE( Offset );
OTV_NAME_ENTER( "MathVariants" );
OTV_LIMIT_CHECK( 10 );
p += 2; /* Skip the MinConnectorOverlap constant */
OTV_OPTIONAL_OFFSET( VCoverage );
OTV_OPTIONAL_OFFSET( HCoverage );
vcnt = FT_NEXT_USHORT( p );
hcnt = FT_NEXT_USHORT( p );
OTV_LIMIT_CHECK( 2 * vcnt + 2 * hcnt );
table_size = 10 + 2 * vcnt + 2 * hcnt;
OTV_SIZE_CHECK( VCoverage );
if ( VCoverage )
otv_Coverage_validate( table + VCoverage, otvalid, (FT_Int)vcnt );
OTV_SIZE_CHECK( HCoverage );
if ( HCoverage )
otv_Coverage_validate( table + HCoverage, otvalid, (FT_Int)hcnt );
for ( i = 0; i < vcnt; i++ )
{
OTV_OPTIONAL_OFFSET( Offset );
OTV_SIZE_CHECK( Offset );
otv_MathGlyphConstruction_validate( table + Offset, otvalid );
}
for ( i = 0; i < hcnt; i++ )
{
OTV_OPTIONAL_OFFSET( Offset );
OTV_SIZE_CHECK( Offset );
otv_MathGlyphConstruction_validate( table + Offset, otvalid );
}
OTV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** MATH TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* sets otvalid->glyph_count */
FT_LOCAL_DEF( void )
otv_MATH_validate( FT_Bytes table,
FT_UInt glyph_count,
FT_Validator ftvalid )
{
OTV_ValidatorRec otvalidrec;
OTV_Validator otvalid = &otvalidrec;
FT_Bytes p = table;
FT_UInt MathConstants, MathGlyphInfo, MathVariants;
otvalid->root = ftvalid;
FT_TRACE3(( "validating MATH table\n" ));
OTV_INIT;
OTV_LIMIT_CHECK( 10 );
if ( FT_NEXT_ULONG( p ) != 0x10000UL ) /* Version */
FT_INVALID_FORMAT;
MathConstants = FT_NEXT_USHORT( p );
MathGlyphInfo = FT_NEXT_USHORT( p );
MathVariants = FT_NEXT_USHORT( p );
otvalid->glyph_count = glyph_count;
otv_MathConstants_validate( table + MathConstants,
otvalid );
otv_MathGlyphInfo_validate( table + MathGlyphInfo,
otvalid );
otv_MathVariants_validate ( table + MathVariants,
otvalid );
FT_TRACE4(( "\n" ));
}
/* END */