Commit e4f7673e46450298db1ce5fda8a3d310cfb50d78
2021-11-13T21:11:00
[truetype] Updates for the forthcoming OpenType 1.9 standard (2/2). * src/truetype/ttgxvar.c (ft_var_load_item_variation_store): s/shortDeltaCount/wordDeltaCount/ (as done in the specification, too). Recognize new format and reject it for now.
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diff --git a/src/truetype/ttgxvar.c b/src/truetype/ttgxvar.c
index 553e27d..7f2db0c 100644
--- a/src/truetype/ttgxvar.c
+++ b/src/truetype/ttgxvar.c
@@ -457,7 +457,8 @@
FT_UShort format;
FT_ULong region_offset;
FT_UInt i, j, k;
- FT_UInt shortDeltaCount;
+ FT_UInt wordDeltaCount;
+ FT_Bool long_words;
GX_Blend blend = face->blend;
GX_ItemVarData varData;
@@ -572,15 +573,18 @@
goto Exit;
if ( FT_READ_USHORT( varData->itemCount ) ||
- FT_READ_USHORT( shortDeltaCount ) ||
+ FT_READ_USHORT( wordDeltaCount ) ||
FT_READ_USHORT( varData->regionIdxCount ) )
goto Exit;
+ long_words = !!( wordDeltaCount & 0x8000 );
+ wordDeltaCount &= 0x7FFF;
+
/* check some data consistency */
- if ( shortDeltaCount > varData->regionIdxCount )
+ if ( wordDeltaCount > varData->regionIdxCount )
{
FT_TRACE2(( "bad short count %d or region count %d\n",
- shortDeltaCount,
+ wordDeltaCount,
varData->regionIdxCount ));
error = FT_THROW( Invalid_Table );
goto Exit;
@@ -616,39 +620,52 @@
/* Parse delta set. */
/* */
- /* On input, deltas are (shortDeltaCount + regionIdxCount) bytes */
- /* each; on output, deltas are expanded to `regionIdxCount' shorts */
- /* each. */
+ /* On input, deltas are (wordDeltaCount + regionIdxCount) bytes */
+ /* each if `long_words` isn't set, and twice as much otherwise. */
+ /* */
+ /* On output, deltas are expanded to `regionIdxCount` shorts each. */
if ( FT_NEW_ARRAY( varData->deltaSet,
varData->regionIdxCount * varData->itemCount ) )
goto Exit;
- /* the delta set is stored as a 2-dimensional array of shorts; */
- /* sign-extend signed bytes to signed shorts */
- for ( j = 0; j < varData->itemCount * varData->regionIdxCount; )
+ /* the delta set is stored as a 2-dimensional array of shorts */
+ if ( long_words )
{
- for ( k = 0; k < shortDeltaCount; k++, j++ )
+ /* new in OpenType 1.9, currently for 'COLR' table only; */
+ /* the deltas are interpreted as 16.16 fixed-point scaling values */
+
+ /* not supported yet */
+
+ error = FT_THROW( Invalid_Table );
+ goto Exit;
+ }
+ else
+ {
+ for ( j = 0; j < varData->itemCount * varData->regionIdxCount; )
{
- /* read the short deltas */
- FT_Short delta;
+ for ( k = 0; k < wordDeltaCount; k++, j++ )
+ {
+ /* read the short deltas */
+ FT_Short delta;
- if ( FT_READ_SHORT( delta ) )
- goto Exit;
+ if ( FT_READ_SHORT( delta ) )
+ goto Exit;
- varData->deltaSet[j] = delta;
- }
+ varData->deltaSet[j] = delta;
+ }
- for ( ; k < varData->regionIdxCount; k++, j++ )
- {
- /* read the (signed) byte deltas */
- FT_Char delta;
+ for ( ; k < varData->regionIdxCount; k++, j++ )
+ {
+ /* read the (signed) byte deltas */
+ FT_Char delta;
- if ( FT_READ_CHAR( delta ) )
- goto Exit;
+ if ( FT_READ_CHAR( delta ) )
+ goto Exit;
- varData->deltaSet[j] = delta;
+ varData->deltaSet[j] = delta;
+ }
}
}
}