/****************************************************************************
*
* gxvopbd.c
*
* TrueTypeGX/AAT opbd table validation (body).
*
* Copyright (C) 2004-2023 by
* suzuki toshiya, Masatake YAMATO, Red Hat K.K.,
* 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.
*
*/
/****************************************************************************
*
* gxvalid is derived from both gxlayout module and otvalid module.
* Development of gxlayout is supported by the Information-technology
* Promotion Agency(IPA), Japan.
*
*/
#include "gxvalid.h"
#include "gxvcommn.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 gxvopbd
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** Data and Types *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
typedef struct GXV_opbd_DataRec_
{
FT_UShort format;
FT_UShort valueOffset_min;
} GXV_opbd_DataRec, *GXV_opbd_Data;
#define GXV_OPBD_DATA( FIELD ) GXV_TABLE_DATA( opbd, FIELD )
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** UTILITY FUNCTIONS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
gxv_opbd_LookupValue_validate( FT_UShort glyph,
GXV_LookupValueCPtr value_p,
GXV_Validator gxvalid )
{
/* offset in LookupTable is measured from the head of opbd table */
FT_Bytes p = gxvalid->root->base + value_p->u;
FT_Bytes limit = gxvalid->root->limit;
FT_Short delta_value;
int i;
if ( value_p->u < GXV_OPBD_DATA( valueOffset_min ) )
GXV_OPBD_DATA( valueOffset_min ) = value_p->u;
for ( i = 0; i < 4; i++ )
{
GXV_LIMIT_CHECK( 2 );
delta_value = FT_NEXT_SHORT( p );
if ( GXV_OPBD_DATA( format ) ) /* format 1, value is ctrl pt. */
{
if ( delta_value == -1 )
continue;
gxv_ctlPoint_validate( glyph, (FT_UShort)delta_value, gxvalid );
}
else /* format 0, value is distance */
continue;
}
}
/*
opbd ---------------------+
|
+===============+ |
| lookup header | |
+===============+ |
| BinSrchHeader | |
+===============+ |
| lastGlyph[0] | |
+---------------+ |
| firstGlyph[0] | | head of opbd sfnt table
+---------------+ | +
| offset[0] | -> | offset [byte]
+===============+ | +
| lastGlyph[1] | | (glyphID - firstGlyph) * 4 * sizeof(FT_Short) [byte]
+---------------+ |
| firstGlyph[1] | |
+---------------+ |
| offset[1] | |
+===============+ |
|
.... |
|
48bit value array |
+===============+ |
| value | <-------+
| |
| |
| |
+---------------+
.... */
static GXV_LookupValueDesc
gxv_opbd_LookupFmt4_transit( FT_UShort relative_gindex,
GXV_LookupValueCPtr base_value_p,
FT_Bytes lookuptbl_limit,
GXV_Validator gxvalid )
{
GXV_LookupValueDesc value;
FT_UNUSED( lookuptbl_limit );
FT_UNUSED( gxvalid );
/* XXX: check range? */
value.u = (FT_UShort)( base_value_p->u +
relative_gindex * 4 * sizeof ( FT_Short ) );
return value;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** opbd TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL_DEF( void )
gxv_opbd_validate( FT_Bytes table,
FT_Face face,
FT_Validator ftvalid )
{
GXV_ValidatorRec gxvalidrec;
GXV_Validator gxvalid = &gxvalidrec;
GXV_opbd_DataRec opbdrec;
GXV_opbd_Data opbd = &opbdrec;
FT_Bytes p = table;
FT_Bytes limit = 0;
FT_ULong version;
gxvalid->root = ftvalid;
gxvalid->table_data = opbd;
gxvalid->face = face;
FT_TRACE3(( "validating `opbd' table\n" ));
GXV_INIT;
GXV_OPBD_DATA( valueOffset_min ) = 0xFFFFU;
GXV_LIMIT_CHECK( 4 + 2 );
version = FT_NEXT_ULONG( p );
GXV_OPBD_DATA( format ) = FT_NEXT_USHORT( p );
/* only 0x00010000 is defined (1996) */
GXV_TRACE(( "(version=0x%08lx)\n", version ));
if ( 0x00010000UL != version )
FT_INVALID_FORMAT;
/* only values 0 and 1 are defined (1996) */
GXV_TRACE(( "(format=0x%04x)\n", GXV_OPBD_DATA( format ) ));
if ( 0x0001 < GXV_OPBD_DATA( format ) )
FT_INVALID_FORMAT;
gxvalid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED;
gxvalid->lookupval_func = gxv_opbd_LookupValue_validate;
gxvalid->lookupfmt4_trans = gxv_opbd_LookupFmt4_transit;
gxv_LookupTable_validate( p, limit, gxvalid );
p += gxvalid->subtable_length;
if ( p > table + GXV_OPBD_DATA( valueOffset_min ) )
{
GXV_TRACE((
"found overlap between LookupTable and opbd_value array\n" ));
FT_INVALID_OFFSET;
}
FT_TRACE4(( "\n" ));
}
/* END */
