From 8e27375cb43b73f0deb7bf931ed3256b7f30248a Mon Sep 17 00:00:00 2001
From: Jeff Gilbert <jgilbert@mozilla.com>
Date: Fri, 31 Aug 2012 16:44:33 -0700
Subject: [PATCH] Bug 784925 - Add MakeCurrent for OGL Layers Readback path -
 r=bjacob

---
 gfx/gl/GLContext.h                   | 44 ++++++++++++++------------
 gfx/layers/opengl/CanvasLayerOGL.cpp | 46 ++++++++++++++++------------
 2 files changed, 50 insertions(+), 40 deletions(-)

diff --git a/gfx/gl/GLContext.h b/gfx/gl/GLContext.h
index c88182a210dd..d6a3d01e4f03 100644
--- a/gfx/gl/GLContext.h
+++ b/gfx/gl/GLContext.h
@@ -1054,6 +1054,26 @@ public:
         }
     }
 
+    void fGetIntegerv(GLenum pname, GLint *params) {
+        switch (pname)
+        {
+            // LOCAL_GL_FRAMEBUFFER_BINDING is equal to
+            // LOCAL_GL_DRAW_FRAMEBUFFER_BINDING_EXT, so we don't need two
+            // cases.
+            case LOCAL_GL_FRAMEBUFFER_BINDING:
+                *params = GetUserBoundDrawFBO();
+                break;
+
+            case LOCAL_GL_READ_FRAMEBUFFER_BINDING_EXT:
+                *params = GetUserBoundReadFBO();
+                break;
+
+            default:
+                raw_fGetIntegerv(pname, params);
+                break;
+        }
+    }
+
 #ifdef DEBUG
     // See comment near BindInternalDrawFBO()
     bool mInInternalBindingMode_DrawFBO;
@@ -1062,6 +1082,8 @@ public:
 
     GLuint GetUserBoundDrawFBO() {
 #ifdef DEBUG
+        MOZ_ASSERT(IsCurrent());
+
         GLint ret = 0;
         // Don't need a branch here, because:
         // LOCAL_GL_DRAW_FRAMEBUFFER_BINDING_EXT == LOCAL_GL_FRAMEBUFFER_BINDING == 0x8CA6
@@ -1093,6 +1115,8 @@ public:
 
     GLuint GetUserBoundReadFBO() {
 #ifdef DEBUG
+        MOZ_ASSERT(IsCurrent());
+
         GLint ret = 0;
         // We use raw_ here because this is debug code and we need to see what
         // the driver thinks.
@@ -2399,26 +2423,6 @@ private:
     }
 
 public:
-    void fGetIntegerv(GLenum pname, GLint *params) {
-        switch (pname)
-        {
-            // LOCAL_GL_FRAMEBUFFER_BINDING is equal to
-            // LOCAL_GL_DRAW_FRAMEBUFFER_BINDING_EXT, so we don't need two
-            // cases.
-            case LOCAL_GL_FRAMEBUFFER_BINDING:
-                *params = GetUserBoundDrawFBO();
-                break;
-
-            case LOCAL_GL_READ_FRAMEBUFFER_BINDING_EXT:
-                *params = GetUserBoundReadFBO();
-                break;
-
-            default:
-                raw_fGetIntegerv(pname, params);
-                break;
-        }
-    }
-
     void GetUIntegerv(GLenum pname, GLuint *params) {
         fGetIntegerv(pname, reinterpret_cast<GLint*>(params));
     }
diff --git a/gfx/layers/opengl/CanvasLayerOGL.cpp b/gfx/layers/opengl/CanvasLayerOGL.cpp
index 96607cf67ac4..d856271e4b54 100644
--- a/gfx/layers/opengl/CanvasLayerOGL.cpp
+++ b/gfx/layers/opengl/CanvasLayerOGL.cpp
@@ -186,6 +186,10 @@ CanvasLayerOGL::UpdateSurface()
   }
 #endif
 
+  if (mCanvasGLContext) {
+    mCanvasGLContext->MakeCurrent();
+  }
+
   if (mCanvasGLContext &&
       !mForceReadback &&
       mCanvasGLContext->GetContextType() == gl()->GetContextType())
@@ -193,7 +197,6 @@ CanvasLayerOGL::UpdateSurface()
     DiscardTempSurface();
 
     // Can texture share, just make sure it's resolved first
-    mCanvasGLContext->MakeCurrent();
     mCanvasGLContext->GuaranteeResolve();
 
     if (gl()->BindOffscreenNeedsTexture(mCanvasGLContext) &&
@@ -202,30 +205,33 @@ CanvasLayerOGL::UpdateSurface()
       mOGLManager->MakeCurrent();
       MakeTextureIfNeeded(gl(), mTexture);
     }
-  } else {
-    nsRefPtr<gfxASurface> updatedAreaSurface;
+    return;
+  }
 
-    if (mCanvasSurface) {
-      updatedAreaSurface = mCanvasSurface;
-    } else if (mCanvasGLContext) {
-      gfxIntSize size(mBounds.width, mBounds.height);
-      nsRefPtr<gfxImageSurface> updatedAreaImageSurface =
+  nsRefPtr<gfxASurface> updatedAreaSurface;
+  if (mCanvasGLContext) {
+    gfxIntSize size(mBounds.width, mBounds.height);
+    nsRefPtr<gfxImageSurface> updatedAreaImageSurface =
         GetTempSurface(size, gfxASurface::ImageFormatARGB32);
 
-      updatedAreaImageSurface->Flush();
-      mCanvasGLContext->ReadScreenIntoImageSurface(updatedAreaImageSurface);
-      updatedAreaImageSurface->MarkDirty();
+    updatedAreaImageSurface->Flush();
+    mCanvasGLContext->ReadScreenIntoImageSurface(updatedAreaImageSurface);
+    updatedAreaImageSurface->MarkDirty();
 
-      updatedAreaSurface = updatedAreaImageSurface;
-    }
-
-    mOGLManager->MakeCurrent();
-    mLayerProgram = gl()->UploadSurfaceToTexture(updatedAreaSurface,
-                                                 mBounds,
-                                                 mTexture,
-                                                 false,
-                                                 nsIntPoint(0, 0));
+    updatedAreaSurface = updatedAreaImageSurface;
+  } else if (mCanvasSurface) {
+    updatedAreaSurface = mCanvasSurface;
+  } else {
+    MOZ_NOT_REACHED("Unhandled canvas layer type.");
+    return;
   }
+
+  mOGLManager->MakeCurrent();
+  mLayerProgram = gl()->UploadSurfaceToTexture(updatedAreaSurface,
+                                               mBounds,
+                                               mTexture,
+                                               false,
+                                               nsIntPoint(0, 0));
 }
 
 void