From: bsalomon <bsalomon@google.com>
Date: Wed, 24 Jun 2015 22:04:13 +0000 (-0700)
Subject: Revert of remove workaround for dx9 angle slow rgba pixel ops (patchset #1 id:1 of... 
X-Git-Tag: accepted/tizen/5.0/unified/20181102.025319~1949
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=47c1ccbcd8e17efdc89a325e314c414a7c75846c;p=platform%2Fupstream%2FlibSkiaSharp.git

Revert of remove workaround for dx9 angle slow rgba pixel ops (patchset #1 id:1 of https://codereview.chromium.org/1207003002/)

Reason for revert:
users are still on dx9 angle :(

Original issue's description:
> remove workaround for dx9 angle slow rgba pixel ops
>
> TBR=robertphillips@google.com
>
> Committed: https://skia.googlesource.com/skia/+/1e1adc33ba1acb9a2ad41c0a5a9b6166ee9d7a2a

TBR=robertphillips@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1205183002
---

diff --git a/include/gpu/gl/GrGLConfig.h b/include/gpu/gl/GrGLConfig.h
index 665ebed..93d5b39 100644
--- a/include/gpu/gl/GrGLConfig.h
+++ b/include/gpu/gl/GrGLConfig.h
@@ -65,6 +65,10 @@
  * The GrGLInterface field fCallback specifies the function ptr and there is an
  * additional field fCallbackData of type intptr_t for client data.
  *
+ * GR_GL_RGBA_8888_PIXEL_OPS_SLOW: Set this to 1 if it is known that performing
+ * glReadPixels / glTex(Sub)Image with format=GL_RGBA, type=GL_UNISIGNED_BYTE is
+ * significantly slower than format=GL_BGRA, type=GL_UNISIGNED_BYTE.
+ *
  * GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL: Set this to 1 if calling
  * glReadPixels to read the entire framebuffer is faster than calling it with
  * the same sized rectangle but with a framebuffer bound that is larger than
@@ -124,6 +128,10 @@
     #define GR_GL_PER_GL_FUNC_CALLBACK                  0
 #endif
 
+#if !defined(GR_GL_RGBA_8888_PIXEL_OPS_SLOW)
+    #define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              0
+#endif
+
 #if !defined(GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL)
     #define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   0
 #endif
diff --git a/include/gpu/gl/GrGLConfig_chrome.h b/include/gpu/gl/GrGLConfig_chrome.h
index b4776ab..ee875b7 100644
--- a/include/gpu/gl/GrGLConfig_chrome.h
+++ b/include/gpu/gl/GrGLConfig_chrome.h
@@ -12,9 +12,13 @@
 #define GR_GL_CHECK_ERROR_START                     0
 
 #if defined(SK_BUILD_FOR_WIN32)
+// For RGBA teximage/readpixels ANGLE will sw-convert to/from BGRA.
+#define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              1
+
 // ANGLE can go faster if the entire fbo is read rather than a subrect
 #define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   1
 #else
+#define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              0
 #define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   0
 #endif
 
@@ -39,4 +43,8 @@
 // (const char* const instead of char**).
 #define GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE       1
 
+#if !defined(GR_GL_IGNORE_ES3_MSAA)
+    #define GR_GL_IGNORE_ES3_MSAA 1
+#endif
+
 #endif
diff --git a/src/gpu/GrGpu.h b/src/gpu/GrGpu.h
index d9c2e18..3bb84a4 100644
--- a/src/gpu/GrGpu.h
+++ b/src/gpu/GrGpu.h
@@ -148,7 +148,8 @@ public:
     }
 
     /**
-     * Called before uploading writing pixels to a GrTexture.
+     * Called before uploading writing pixels to a GrTexture when the src pixel config doesn't
+     * match the texture's config.
      */
     virtual bool canWriteTexturePixels(const GrTexture*, GrPixelConfig srcConfig) const = 0;
 
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 6366b44..20669b8 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -270,14 +270,21 @@ void GrGLGpu::contextAbandoned() {
 ///////////////////////////////////////////////////////////////////////////////
 GrPixelConfig GrGLGpu::preferredReadPixelsConfig(GrPixelConfig readConfig,
                                                  GrPixelConfig surfaceConfig) const {
-    if (kMesa_GrGLDriver == this->glContext().driver() &&
-        GrBytesPerPixel(readConfig) == 4 && GrPixelConfigSwapRAndB(readConfig) == 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 compile-time or runtime check.
+    if (GR_GL_RGBA_8888_PIXEL_OPS_SLOW && kRGBA_8888_GrPixelConfig == readConfig) {
+        return kBGRA_8888_GrPixelConfig;
+    } else if (kMesa_GrGLDriver == this->glContext().driver() &&
+               GrBytesPerPixel(readConfig) == 4 &&
+               GrPixelConfigSwapRAndB(readConfig) == 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 if (readConfig == kBGRA_8888_GrPixelConfig &&
-               !this->glCaps().readPixelsSupported(this->glInterface(), GR_GL_BGRA,
-                                                   GR_GL_UNSIGNED_BYTE, surfaceConfig)) {
+    } else if (readConfig == kBGRA_8888_GrPixelConfig
+            && !this->glCaps().readPixelsSupported(
+                this->glInterface(),
+                GR_GL_BGRA,
+                GR_GL_UNSIGNED_BYTE,
+                surfaceConfig
+            )) {
         return kRGBA_8888_GrPixelConfig;
     } else {
         return readConfig;
@@ -286,7 +293,11 @@ GrPixelConfig GrGLGpu::preferredReadPixelsConfig(GrPixelConfig readConfig,
 
 GrPixelConfig GrGLGpu::preferredWritePixelsConfig(GrPixelConfig writeConfig,
                                                   GrPixelConfig surfaceConfig) const {
-    return writeConfig;
+    if (GR_GL_RGBA_8888_PIXEL_OPS_SLOW && kRGBA_8888_GrPixelConfig == writeConfig) {
+        return kBGRA_8888_GrPixelConfig;
+    } else {
+        return writeConfig;
+    }
 }
 
 bool GrGLGpu::canWriteTexturePixels(const GrTexture* texture, GrPixelConfig srcConfig) const {