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/****************************************************************************
*
* gxvmort1.c
*
* TrueTypeGX/AAT mort table validation
* body for type1 (Contextual Substitution) subtable.
*
* Copyright (C) 2005-2021 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 "gxvmort.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 gxvmort
typedef struct GXV_mort_subtable_type1_StateOptRec_
{
FT_UShort substitutionTable;
FT_UShort substitutionTable_length;
} GXV_mort_subtable_type1_StateOptRec,
*GXV_mort_subtable_type1_StateOptRecData;
#define GXV_MORT_SUBTABLE_TYPE1_HEADER_SIZE \
( GXV_STATETABLE_HEADER_SIZE + 2 )
static void
gxv_mort_subtable_type1_substitutionTable_load( FT_Bytes table,
FT_Bytes limit,
GXV_Validator gxvalid )
{
FT_Bytes p = table;
GXV_mort_subtable_type1_StateOptRecData optdata =
(GXV_mort_subtable_type1_StateOptRecData)gxvalid->statetable.optdata;
GXV_LIMIT_CHECK( 2 );
optdata->substitutionTable = FT_NEXT_USHORT( p );
}
static void
gxv_mort_subtable_type1_subtable_setup( FT_UShort table_size,
FT_UShort classTable,
FT_UShort stateArray,
FT_UShort entryTable,
FT_UShort* classTable_length_p,
FT_UShort* stateArray_length_p,
FT_UShort* entryTable_length_p,
GXV_Validator gxvalid )
{
FT_UShort o[4];
FT_UShort *l[4];
FT_UShort buff[5];
GXV_mort_subtable_type1_StateOptRecData optdata =
(GXV_mort_subtable_type1_StateOptRecData)gxvalid->statetable.optdata;
o[0] = classTable;
o[1] = stateArray;
o[2] = entryTable;
o[3] = optdata->substitutionTable;
l[0] = classTable_length_p;
l[1] = stateArray_length_p;
l[2] = entryTable_length_p;
l[3] = &( optdata->substitutionTable_length );
gxv_set_length_by_ushort_offset( o, l, buff, 4, table_size, gxvalid );
}
static void
gxv_mort_subtable_type1_offset_to_subst_validate(
FT_Short wordOffset,
const FT_String* tag,
FT_Byte state,
GXV_Validator gxvalid )
{
FT_UShort substTable;
FT_UShort substTable_limit;
FT_UNUSED( tag );
FT_UNUSED( state );
substTable =
((GXV_mort_subtable_type1_StateOptRec *)
(gxvalid->statetable.optdata))->substitutionTable;
substTable_limit =
(FT_UShort)( substTable +
((GXV_mort_subtable_type1_StateOptRec *)
(gxvalid->statetable.optdata))->substitutionTable_length );
gxvalid->min_gid = (FT_UShort)( ( substTable - wordOffset * 2 ) / 2 );
gxvalid->max_gid = (FT_UShort)( ( substTable_limit - wordOffset * 2 ) / 2 );
gxvalid->max_gid = (FT_UShort)( FT_MAX( gxvalid->max_gid,
gxvalid->face->num_glyphs ) );
/* XXX: check range? */
/* TODO: min_gid & max_gid comparison with ClassTable contents */
}
static void
gxv_mort_subtable_type1_entry_validate(
FT_Byte state,
FT_UShort flags,
GXV_StateTable_GlyphOffsetCPtr glyphOffset_p,
FT_Bytes table,
FT_Bytes limit,
GXV_Validator gxvalid )
{
#ifdef GXV_LOAD_UNUSED_VARS
FT_UShort setMark;
FT_UShort dontAdvance;
#endif
FT_UShort reserved;
FT_Short markOffset;
FT_Short currentOffset;
FT_UNUSED( table );
FT_UNUSED( limit );
#ifdef GXV_LOAD_UNUSED_VARS
setMark = (FT_UShort)( flags >> 15 );
dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 );
#endif
reserved = (FT_UShort)( flags & 0x3FFF );
markOffset = (FT_Short)( glyphOffset_p->ul >> 16 );
currentOffset = (FT_Short)( glyphOffset_p->ul );
if ( 0 < reserved )
{
GXV_TRACE(( " non-zero bits found in reserved range\n" ));
GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
}
gxv_mort_subtable_type1_offset_to_subst_validate( markOffset,
"markOffset",
state,
gxvalid );
gxv_mort_subtable_type1_offset_to_subst_validate( currentOffset,
"currentOffset",
state,
gxvalid );
}
static void
gxv_mort_subtable_type1_substTable_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator gxvalid )
{
FT_Bytes p = table;
FT_UShort num_gids = (FT_UShort)(
((GXV_mort_subtable_type1_StateOptRec *)
(gxvalid->statetable.optdata))->substitutionTable_length / 2 );
FT_UShort i;
GXV_NAME_ENTER( "validating contents of substitutionTable" );
for ( i = 0; i < num_gids; i++ )
{
FT_UShort dst_gid;
GXV_LIMIT_CHECK( 2 );
dst_gid = FT_NEXT_USHORT( p );
if ( dst_gid >= 0xFFFFU )
continue;
if ( dst_gid < gxvalid->min_gid || gxvalid->max_gid < dst_gid )
{
GXV_TRACE(( "substTable include a strange gid[%d]=%d >"
" out of define range (%d..%d)\n",
i, dst_gid, gxvalid->min_gid, gxvalid->max_gid ));
GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID );
}
}
GXV_EXIT;
}
/*
* subtable for Contextual glyph substitution is a modified StateTable.
* In addition to classTable, stateArray, and entryTable, the field
* `substitutionTable' is added.
*/
FT_LOCAL_DEF( void )
gxv_mort_subtable_type1_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator gxvalid )
{
FT_Bytes p = table;
GXV_mort_subtable_type1_StateOptRec st_rec;
GXV_NAME_ENTER( "mort chain subtable type1 (Contextual Glyph Subst)" );
GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE1_HEADER_SIZE );
gxvalid->statetable.optdata =
&st_rec;
gxvalid->statetable.optdata_load_func =
gxv_mort_subtable_type1_substitutionTable_load;
gxvalid->statetable.subtable_setup_func =
gxv_mort_subtable_type1_subtable_setup;
gxvalid->statetable.entry_glyphoffset_fmt =
GXV_GLYPHOFFSET_ULONG;
gxvalid->statetable.entry_validate_func =
gxv_mort_subtable_type1_entry_validate;
gxv_StateTable_validate( p, limit, gxvalid );
gxv_mort_subtable_type1_substTable_validate(
table + st_rec.substitutionTable,
table + st_rec.substitutionTable + st_rec.substitutionTable_length,
gxvalid );
GXV_EXIT;
}
/* END */