From 17a83b748ef0ab029c63734d0407867c9f0cede9 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Wed, 26 Feb 2025 14:40:02 -0700
Subject: [PATCH] [COLRv1] Optimize PaintColrLayers instead of PaintComposite

See https://github.com/googlefonts/colr-gradients-spec/issues/369#issuecomment-1816913943
and onwards.
---
 src/OT/Color/COLR/COLR.hh | 4 ++--
 src/hb-ft-colr.hh         | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/OT/Color/COLR/COLR.hh b/src/OT/Color/COLR/COLR.hh
index cf10e894a..f9062682c 100644
--- a/src/OT/Color/COLR/COLR.hh
+++ b/src/OT/Color/COLR/COLR.hh
@@ -1511,10 +1511,12 @@ struct PaintComposite
   void paint_glyph (hb_paint_context_t *c) const
   {
     TRACE_PAINT (this);
+    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 */
@@ -2714,9 +2716,7 @@ void PaintColrLayers::paint_glyph (hb_paint_context_t *c) const
       return;
 
     const Paint &paint = paint_offset_lists.get_paint (i);
-    c->funcs->push_group (c->data);
     c->recurse (paint);
-    c->funcs->pop_group (c->data, HB_PAINT_COMPOSITE_MODE_SRC_OVER);
   }
 }
 
diff --git a/src/hb-ft-colr.hh b/src/hb-ft-colr.hh
index c96698369..4151f7200 100644
--- a/src/hb-ft-colr.hh
+++ b/src/hb-ft-colr.hh
@@ -229,9 +229,7 @@ _hb_ft_paint (hb_ft_paint_context_t *c,
 	if (unlikely (!node.visit ((uintptr_t) other_paint.p)))
 	  continue;
 
-	c->funcs->push_group (c->data);
 	c->recurse (other_paint);
-	c->funcs->pop_group (c->data, HB_PAINT_COMPOSITE_MODE_SRC_OVER);
       }
     }
     break;
@@ -451,10 +449,12 @@ _hb_ft_paint (hb_ft_paint_context_t *c,
     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;