From 04e9523e5f9cdc19b7116dae4f3ad6110f1e65a6 Mon Sep 17 00:00:00 2001
From: pylbrecht <palbrecht@mailbox.org>
Date: Tue, 3 Dec 2019 18:30:39 +0100
Subject: [PATCH] Use push_layer_with_blend() only when necessary

push_layer_with_blend() comes at a performance cost, so we only use it
on blend modes that require it.
---
 components/canvas/raqote_backend.rs | 41 +++++++++++++++++++++++++----
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/components/canvas/raqote_backend.rs b/components/canvas/raqote_backend.rs
index b940277a0f3..01eaa15632c 100644
--- a/components/canvas/raqote_backend.rs
+++ b/components/canvas/raqote_backend.rs
@@ -329,11 +329,42 @@ impl GenericDrawTarget for raqote::DrawTarget {
         warn!("no support for drawing shadows");
     }
     fn fill(&mut self, path: &Path, pattern: Pattern, draw_options: &DrawOptions) {
-        let mut options = draw_options.as_raqote().clone();
-        self.push_layer_with_blend(1., options.blend_mode);
-        options.blend_mode = raqote::BlendMode::SrcOver;
-        self.fill(path.as_raqote(), pattern.as_raqote(), &options);
-        self.pop_layer();
+        match draw_options.as_raqote().blend_mode {
+            raqote::BlendMode::Src => {
+                self.clear(raqote::SolidSource::from_unpremultiplied_argb(0, 0, 0, 0));
+                self.fill(
+                    path.as_raqote(),
+                    pattern.as_raqote(),
+                    draw_options.as_raqote(),
+                );
+            },
+            raqote::BlendMode::SrcAtop |
+            raqote::BlendMode::DstOut |
+            raqote::BlendMode::Add |
+            raqote::BlendMode::Xor |
+            raqote::BlendMode::DstOver |
+            raqote::BlendMode::SrcOver => {
+                self.fill(
+                    path.as_raqote(),
+                    pattern.as_raqote(),
+                    draw_options.as_raqote(),
+                );
+            },
+            raqote::BlendMode::SrcIn |
+            raqote::BlendMode::SrcOut |
+            raqote::BlendMode::DstIn |
+            raqote::BlendMode::DstAtop => {
+                let mut options = draw_options.as_raqote().clone();
+                self.push_layer_with_blend(1., options.blend_mode);
+                options.blend_mode = raqote::BlendMode::SrcOver;
+                self.fill(path.as_raqote(), pattern.as_raqote(), &options);
+                self.pop_layer();
+            },
+            _ => warn!(
+                "unrecognized blend mode: {:?}",
+                draw_options.as_raqote().blend_mode
+            ),
+        }
     }
     fn fill_rect(
         &mut self,