commit 5d1d79a1f9d351e6f2390d844e6a7361d7d607ca
author commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Fri May 24 18:52:52 2013 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Fri May 24 18:52:52 2013 +0000
tree 5894513ee20020fd51cb6a3ab0a6b27f8bb3dea4
parent 912e68ec469f714ec76b5ed419e5b7ea10e45500

fix slowness of getImageData() for CanvasRenderingContext2D in linux due to un-optimized format for glReadPixels

This is a continuation of https://codereview.chromium.org/15331003/

BUG=242093
R=robertphillips@google.com, jun.a.jiang@intel.com, bsalomon@google.com

Author: bsalomon@google.com

Review URL: https://chromiumcodereview.appspot.com/15746007

git-svn-id: http://skia.googlecode.com/svn/trunk@9280 2bbb7eff-a529-9590-31e7-b0007b416f81

src/gpu/gl/GrGpuGL.cpp

diff --git a/src/gpu/gl/GrGpuGL.cpp b/src/gpu/gl/GrGpuGL.cpp
index 035ef3b..0c47060 100644
--- a/src/gpu/gl/GrGpuGL.cpp
+++ b/src/gpu/gl/GrGpuGL.cpp
@@ -266,21 +266,28 @@
 }
 
 namespace {
-GrPixelConfig preferred_pixel_ops_config(GrPixelConfig config) {
-    if (GR_GL_RGBA_8888_PIXEL_OPS_SLOW && kRGBA_8888_GrPixelConfig == config) {
+GrPixelConfig preferred_pixel_ops_config(GrPixelConfig cpuConfig, GrPixelConfig surfaceConfig) {
+    if (GR_GL_RGBA_8888_PIXEL_OPS_SLOW && kRGBA_8888_GrPixelConfig == cpuConfig) {
         return kBGRA_8888_GrPixelConfig;
+    } else if (GrBytesPerPixel(cpuConfig) == 4 &&
+                GrPixelConfigSwapRAndB(cpuConfig) == surfaceConfig) {
+        // Mesa 3D takes a slow path on when reading back  BGRA from an RGBA surface and vice-versa.
+        // Perhaps this should be guarded by some compiletime or runtime check.
+        return surfaceConfig;
     } else {
-        return config;
+        return cpuConfig;
     }
 }
 }
 
-GrPixelConfig GrGpuGL::preferredReadPixelsConfig(GrPixelConfig config) const {
-    return preferred_pixel_ops_config(config);
+GrPixelConfig GrGpuGL::preferredReadPixelsConfig(GrPixelConfig readConfig,
+                                                 GrPixelConfig surfaceConfig) const {
+    return preferred_pixel_ops_config(readConfig, surfaceConfig);
 }
 
-GrPixelConfig GrGpuGL::preferredWritePixelsConfig(GrPixelConfig config) const {
-    return preferred_pixel_ops_config(config);
+GrPixelConfig GrGpuGL::preferredWritePixelsConfig(GrPixelConfig writeConfig,
+                                                  GrPixelConfig surfaceConfig) const {
+    return preferred_pixel_ops_config(writeConfig, surfaceConfig);
 }
 
 bool GrGpuGL::canWriteTexturePixels(const GrTexture* texture, GrPixelConfig srcConfig) const {