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[gxvar] Optimize loading of 'gvar' table.

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* src/truetype/ttgxvar.c (tt_var_load_item_variation_store,
  tt_var_load_delta_set_index_mapping, ft_var_load_gvar): Use frames to
  reduce bounds checking.
  (TT_Vary_Apply_Glyph_Deltas): Better macro usage.
This commit is contained in:
Behdad Esfahbod
2025-05-23 08:03:59 +02:00
committed by Werner Lemberg
parent 42a649be49
commit 75b84313cf
1 changed files with 84 additions and 21 deletions
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105
src/truetype/ttgxvar.c
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@@ -489,8 +489,9 @@
FT_UShort axis_count;
FT_UInt region_count;
FT_UInt i, j;
FT_Bool long_words;
FT_UInt i, j;
FT_Byte* bytes;
FT_Bool long_words;
GX_Blend blend = ttface->blend;
FT_ULong* dataOffsetArray = NULL;
@@ -526,11 +527,15 @@
if ( FT_QNEW_ARRAY( dataOffsetArray, data_count ) )
goto Exit;
if ( FT_FRAME_ENTER( data_count * 4 ) )
goto Exit;
bytes = stream->cursor;
for ( i = 0; i < data_count; i++ )
{
if ( FT_READ_ULONG( dataOffsetArray[i] ) )
goto Exit;
}
dataOffsetArray[i] = FT_NEXT_ULONG( bytes );
FT_FRAME_EXIT();
/* parse array of region records (region list) */
if ( FT_STREAM_SEEK( offset + region_offset ) )
@@ -564,13 +569,26 @@
goto Exit;
itemStore->regionCount = region_count;
for ( i = 0; i < itemStore->regionCount; i++ )
if ( FT_FRAME_ENTER( (FT_Long)region_count * axis_count * 6 ) )
{
FT_TRACE2(( "tt_var_load_item_variation_store:"
" not enough data for variation regions\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
bytes = stream->cursor;
for ( i = 0; i < region_count; i++ )
{
GX_AxisCoords axisCoords;
if ( FT_NEW_ARRAY( itemStore->varRegionList[i].axisList, axis_count ) )
{
FT_FRAME_EXIT();
goto Exit;
}
axisCoords = itemStore->varRegionList[i].axisList;
@@ -579,10 +597,9 @@
FT_Int start, peak, end;
if ( FT_READ_SHORT( start ) ||
FT_READ_SHORT( peak ) ||
FT_READ_SHORT( end ) )
goto Exit;
start = FT_NEXT_SHORT( bytes );
peak = FT_NEXT_SHORT( bytes );
end = FT_NEXT_SHORT( bytes );
/* immediately tag invalid ranges with special peak = 0 */
if ( ( start < 0 && end > 0 ) || start > peak || peak > end )
@@ -594,6 +611,8 @@
}
}
FT_FRAME_EXIT();
/* end of region list parse */
/* use dataOffsetArray now to parse varData items */
@@ -648,20 +667,32 @@
varData->wordDeltaCount = word_delta_count;
varData->longWords = long_words;
if ( FT_FRAME_ENTER( region_idx_count * 2 ) )
{
FT_TRACE2(( "tt_var_load_item_variation_store:"
" not enough data for region indices\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
bytes = stream->cursor;
for ( j = 0; j < varData->regionIdxCount; j++ )
{
if ( FT_READ_USHORT( varData->regionIndices[j] ) )
goto Exit;
varData->regionIndices[j] = FT_NEXT_USHORT( bytes );
if ( varData->regionIndices[j] >= itemStore->regionCount )
{
FT_TRACE2(( "bad region index %d\n",
varData->regionIndices[j] ));
FT_FRAME_EXIT();
error = FT_THROW( Invalid_Table );
goto Exit;
}
}
FT_FRAME_EXIT();
per_region_size = word_delta_count + region_idx_count;
if ( long_words )
per_region_size *= 2;
@@ -706,6 +737,7 @@
FT_UInt innerIndexMask;
FT_ULong i;
FT_UInt j;
FT_Byte* bytes;
if ( FT_STREAM_SEEK( offset ) ||
@@ -757,6 +789,16 @@
if ( FT_NEW_ARRAY( map->outerIndex, map->mapCount ) )
goto Exit;
if ( FT_FRAME_ENTER( map->mapCount * entrySize ) )
{
FT_TRACE2(( "tt_var_load_delta_set_index_mapping:"
" invalid number of delta-set index mappings\n" ));
error = FT_THROW( Invalid_Table );
goto Exit;
}
bytes = stream->cursor;
for ( i = 0; i < map->mapCount; i++ )
{
FT_UInt mapData = 0;
@@ -769,9 +811,7 @@
FT_Byte data;
if ( FT_READ_BYTE( data ) )
goto Exit;
data = FT_NEXT_BYTE( bytes );
mapData = ( mapData << 8 ) | data;
}
@@ -812,6 +852,8 @@
map->innerIndex[i] = innerIndex;
}
FT_FRAME_EXIT();
Exit:
return error;
}
@@ -1643,6 +1685,7 @@
GX_Blend blend = face->blend;
FT_Error error;
FT_UInt i, j;
FT_Byte* bytes;
FT_ULong table_len;
FT_ULong gvar_start;
FT_ULong offsetToData;
@@ -1734,6 +1777,8 @@
if ( FT_FRAME_ENTER( offsets_len ) )
goto Exit;
bytes = stream->cursor;
/* offsets (one more offset than glyphs, to mark size of last) */
if ( FT_QNEW_ARRAY( blend->glyphoffsets, gvar_head.glyphCount + 1 ) )
goto Fail2;
@@ -1744,9 +1789,17 @@
FT_ULong max_offset = 0;
if ( stream->limit - stream->cursor < gvar_head.glyphCount * 4 )
{
FT_TRACE2(( "ft_var_load_gvar:"
" glyph variation data offset not enough\n" ));
error = FT_THROW( Invalid_Table );
goto Fail;
}
for ( i = 0; i <= gvar_head.glyphCount; i++ )
{
blend->glyphoffsets[i] = offsetToData + FT_GET_ULONG();
blend->glyphoffsets[i] = offsetToData + FT_NEXT_ULONG( bytes );
if ( max_offset <= blend->glyphoffsets[i] )
max_offset = blend->glyphoffsets[i];
@@ -1774,9 +1827,17 @@
FT_ULong max_offset = 0;
if ( stream->limit - stream->cursor < gvar_head.glyphCount * 2 )
{
FT_TRACE2(( "ft_var_load_gvar:"
" glyph variation data offset not enough\n" ));
error = FT_THROW( Invalid_Table );
goto Fail;
}
for ( i = 0; i <= gvar_head.glyphCount; i++ )
{
blend->glyphoffsets[i] = offsetToData + FT_GET_USHORT() * 2;
blend->glyphoffsets[i] = offsetToData + FT_NEXT_USHORT( bytes ) * 2;
if ( max_offset <= blend->glyphoffsets[i] )
max_offset = blend->glyphoffsets[i];
@@ -1814,6 +1875,8 @@
goto Fail;
}
bytes = stream->cursor;
if ( FT_QNEW_ARRAY( blend->tuplecoords,
gvar_head.axisCount * gvar_head.globalCoordCount ) )
goto Fail2;
@@ -1824,7 +1887,7 @@
for ( j = 0; j < (FT_UInt)gvar_head.axisCount; j++ )
{
blend->tuplecoords[i * gvar_head.axisCount + j] =
FT_fdot14ToFixed( FT_GET_SHORT() );
FT_fdot14ToFixed( FT_NEXT_SHORT( bytes ) );
FT_TRACE5(( "%.5f ",
(double)blend->tuplecoords[i * gvar_head.axisCount + j] / 65536 ));
}
@@ -4213,8 +4276,8 @@
error = FT_THROW( Invalid_Table );
goto Exit;
}
tupleDataSize = FT_NEXT_USHORT( stream->cursor );
tupleIndex = FT_NEXT_USHORT( stream->cursor );
tupleDataSize = FT_GET_USHORT();
tupleIndex = FT_GET_USHORT();
if ( tupleIndex & GX_TI_EMBEDDED_TUPLE_COORD )
{