commit d045de78c1ff7b32f3d7082591f4112d1f8f796a
author Behdad Esfahbod <behdad@behdad.org> Sat Jan 07 13:55:17 2023 -0700
committer Behdad Esfahbod <behdad@behdad.org> Sat Jan 07 13:56:43 2023 -0700
tree e1324a554699fb421185a33e4943f22eb29aa406
parent 5ea5aacda9d14833a66e9d9869c69eda0bb4034a

[paint] Optimize PAINT_COMPOSITE

At the start of each paint call the current group is clear.
So we don't need to start a new group for the backdrop paint.

A paint composite really needs one group push, not two.

src/OT/Color/COLR/COLR.hh

diff --git a/src/OT/Color/COLR/COLR.hh b/src/OT/Color/COLR/COLR.hh
index be1ac08..d46384c 100644
--- a/src/OT/Color/COLR/COLR.hh
+++ b/src/OT/Color/COLR/COLR.hh
@@ -1245,12 +1245,10 @@
 
   void paint_glyph (hb_paint_context_t *c) const
   {
-    c->funcs->push_group (c->data);
     c->recurse (this+backdrop);
     c->funcs->push_group (c->data);
     c->recurse (this+src);
     c->funcs->pop_group (c->data, (hb_paint_composite_mode_t) (int) mode);
-    c->funcs->pop_group (c->data, HB_PAINT_COMPOSITE_MODE_SRC_OVER);
   }
 
   HBUINT8		format; /* format = 32 */

src/hb-ft-colr.hh

diff --git a/src/hb-ft-colr.hh b/src/hb-ft-colr.hh
index 11a27a0..e1f234f 100644
--- a/src/hb-ft-colr.hh
+++ b/src/hb-ft-colr.hh
@@ -392,12 +392,10 @@
     break;
     case FT_COLR_PAINTFORMAT_COMPOSITE:
     {
-      c->funcs->push_group (c->data);
       c->recurse (paint.u.composite.backdrop_paint);
       c->funcs->push_group (c->data);
       c->recurse (paint.u.composite.source_paint);
       c->funcs->pop_group (c->data, _hb_ft_paint_composite_mode (paint.u.composite.composite_mode));
-      c->funcs->pop_group (c->data, HB_PAINT_COMPOSITE_MODE_SRC_OVER);
     }
     break;