Commit 919561ca8c2a7b245644767b49d08e638d34d4eb
2022-07-30T12:09:21
[sfnt] Implement VarClipBox. * src/sfnt/ttcolr.c (tt_face_get_color_glyph_clipbox): Depending on the format, read `var_index_base`, then retrieve and apply scaled deltas.
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diff --git a/src/sfnt/ttcolr.c b/src/sfnt/ttcolr.c
index 9a1e9a3..25051a4 100644
--- a/src/sfnt/ttcolr.c
+++ b/src/sfnt/ttcolr.c
@@ -1362,7 +1362,7 @@
clip_list_format = FT_NEXT_BYTE ( p );
/* Format byte used here to be able to upgrade ClipList for >16bit */
- /* glyph ids; for now we can expect it to be 0. */
+ /* glyph ids; for now we can expect it to be 1. */
if ( !( clip_list_format == 1 ) )
return 0;
@@ -1390,7 +1390,7 @@
format = FT_NEXT_BYTE( p1 );
- if ( format > 1 )
+ if ( format > 2 )
return 0;
/* Check whether we can extract four `FWORD`. */
@@ -1410,6 +1410,34 @@
font_clip_box.yMax = FT_MulFix( FT_NEXT_SHORT( p1 ),
face->root.size->metrics.y_scale );
+#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
+ if ( VARIABLE_COLRV1_ENABLED && format == 2 )
+ {
+ FT_ULong var_index_base = 0;
+ /* varIndexBase offset for clipbox is 3 at most. */
+ FT_ItemVarDelta item_deltas[4] = { 0, 0, 0, 0 };
+
+
+ /* Check whether we can extract a 32-bit VarIdxBase now. */
+ if ( p1 > limit - 4 )
+ return 0;
+
+ var_index_base = FT_NEXT_ULONG( p1 );
+
+ if ( !get_deltas_for_var_index_base( face, colr, var_index_base, 4,
+ item_deltas ) )
+ return 0;
+
+ font_clip_box.xMin +=
+ FT_MulFix( item_deltas[0], face->root.size->metrics.x_scale );
+ font_clip_box.yMin +=
+ FT_MulFix( item_deltas[1], face->root.size->metrics.y_scale );
+ font_clip_box.xMax +=
+ FT_MulFix( item_deltas[2], face->root.size->metrics.x_scale );
+ font_clip_box.yMax +=
+ FT_MulFix( item_deltas[3], face->root.size->metrics.y_scale );
+ }
+#endif
/* Make 4 corner points (xMin, yMin), (xMax, yMax) and transform */
/* them. If we we would only transform two corner points and */