File 0001-scenes-opengl-Avoid-blending-for-entirely-... of Package kwin5

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File 0001-scenes-opengl-Avoid-blending-for-entirely-opaque-Sur.patch of Package kwin5

From 21c7298274bb40cd05f7319d7d5ec30fc24cc325 Mon Sep 17 00:00:00 2001
From: Fabian Vogt <fabian@ritter-vogt.de>
Date: Fri, 6 Aug 2021 11:01:18 +0200
Subject: [PATCH] scenes/opengl: Avoid blending for entirely opaque
 SurfaceItems

Blending is quite expensive especially with software rendering.
In the case of Firefox on Wayland, it uses a ARGB8888 buffer but marks the
entire surface as opaque, so the alpha channel can be ignored.

CCBUG: 440386
---
 src/plugins/scenes/opengl/scene_opengl.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/plugins/scenes/opengl/scene_opengl.cpp b/src/plugins/scenes/opengl/scene_opengl.cpp
index 0b457a0b9..19e810434 100644
--- a/src/plugins/scenes/opengl/scene_opengl.cpp
+++ b/src/plugins/scenes/opengl/scene_opengl.cpp
@@ -983,12 +983,14 @@ void OpenGLWindow::createRenderNode(Item *item, RenderContext *context)
         if (!quads.isEmpty()) {
             SurfacePixmap *pixmap = surfaceItem->pixmap();
             if (pixmap) {
+                // Don't bother with blending if the entire surface is opaque
+                bool hasAlpha = pixmap->hasAlphaChannel() && !surfaceItem->shape().subtracted(surfaceItem->opaque()).isEmpty();
                 context->renderNodes.append(RenderNode{
                     .texture = bindSurfaceTexture(surfaceItem),
                     .quads = quads,
                     .transformMatrix = transformation(item, context),
                     .opacity = context->paintData.opacity(),
-                    .hasAlpha = pixmap->hasAlphaChannel(),
+                    .hasAlpha = hasAlpha,
                     .coordinateType = UnnormalizedCoordinates,
                 });
             }
-- 
2.32.0

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File 0001-scenes-opengl-Avoid-blending-for-entirely-opaque-Sur.patch of Package kwin5

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