Bug 715232: Don't attempt to CopyTexImage from an RGB framebuffer to an RGBA texture. r=joedrew

gfx/layers/opengl/ContainerLayerOGL.cpp

@@ -214,6 +214,7 @@ ContainerRender(Container* aContainer,
     framebufferRect -= childOffset; 
     aManager->CreateFBOWithTexture(framebufferRect,
                                    mode,
+                                   aPreviousFrameBuffer,
                                    &frameBuffer,
                                    &containerSurface);
     childOffset.x = visibleRect.x;

gfx/layers/opengl/LayerManagerOGL.cpp

@@ -1132,8 +1132,33 @@ LayerManagerOGL::SetLayerProgramProjectionMatrix(const gfx3DMatrix& aMatrix)
   } FOR_EACH_LAYER_PROGRAM_END
 }
 
+static GLenum
+GetFrameBufferInternalFormat(GLContext* gl,
+                             GLuint aCurrentFrameBuffer,
+                             nsIWidget* aWidget)
+{
+  if (aCurrentFrameBuffer == 0) { // default framebuffer
+    return aWidget->GetGLFrameBufferFormat();
+  }
+  return LOCAL_GL_RGBA;
+}
+
+static bool
+AreFormatsCompatibleForCopyTexImage2D(GLenum aF1, GLenum aF2)
+{
+  // GL requires that the implementation has to handle copies between
+  // different formats, so all are "compatible".  GLES does not
+  // require that.
+#ifdef USE_GLES2
+  return (aF1 == aF2);
+#else
+  return true;
+#endif
+}
+
 void
 LayerManagerOGL::CreateFBOWithTexture(const nsIntRect& aRect, InitMode aInit,
+                                      GLuint aCurrentFrameBuffer,
                                       GLuint *aFBO, GLuint *aTexture)
 {
   GLuint tex, fbo;
@@ -1142,12 +1167,40 @@ LayerManagerOGL::CreateFBOWithTexture(const nsIntRect& aRect, InitMode aInit,
   mGLContext->fGenTextures(1, &tex);
   mGLContext->fBindTexture(mFBOTextureTarget, tex);
   if (aInit == InitModeCopy) {
-    mGLContext->fCopyTexImage2D(mFBOTextureTarget,
-                                0,
-                                LOCAL_GL_RGBA,
-                                aRect.x, aRect.y,
-                                aRect.width, aRect.height,
-                                0);
+    // We're going to create an RGBA temporary fbo.  But to
+    // CopyTexImage() from the current framebuffer, the framebuffer's
+    // format has to be compatible with the new texture's.  So we
+    // check the format of the framebuffer here and take a slow path
+    // if it's incompatible.
+    GLenum format =
+      GetFrameBufferInternalFormat(gl(), aCurrentFrameBuffer, mWidget);
+    if (AreFormatsCompatibleForCopyTexImage2D(format, LOCAL_GL_RGBA)) {
+      mGLContext->fCopyTexImage2D(mFBOTextureTarget,
+                                  0,
+                                  LOCAL_GL_RGBA,
+                                  aRect.x, aRect.y,
+                                  aRect.width, aRect.height,
+                                  0);
+    } else {
+      // Curses, incompatible formats.  Take a slow path.
+      //
+      // XXX Technically CopyTexSubImage2D also has the requirement of
+      // matching formats, but it doesn't seem to affect us in the
+      // real world.
+      mGLContext->fTexImage2D(mFBOTextureTarget,
+                              0,
+                              LOCAL_GL_RGBA,
+                              aRect.width, aRect.height,
+                              0,
+                              LOCAL_GL_RGBA,
+                              LOCAL_GL_UNSIGNED_BYTE,
+                              NULL);
+      mGLContext->fCopyTexSubImage2D(mFBOTextureTarget,
+                                     0,    // level
+                                     0, 0, // offset
+                                     aRect.x, aRect.y,
+                                     aRect.width, aRect.height);
+    }
   } else {
     mGLContext->fTexImage2D(mFBOTextureTarget,
                             0,

gfx/layers/opengl/LayerManagerOGL.h

@@ -308,6 +308,7 @@ public:
    * texture types.
    */
   void CreateFBOWithTexture(const nsIntRect& aRect, InitMode aInit,
+                            GLuint aCurrentFrameBuffer,
                             GLuint *aFBO, GLuint *aTexture);
 
   GLuint QuadVBO() { return mQuadVBO; }

widget/gonk/nsWindow.cpp

@@ -449,3 +449,15 @@ nsWindow::UserActivity()
         mIdleService->ResetIdleTimeOut();
     }
 }
+
+PRUint32
+nsWindow::GetGLFrameBufferFormat()
+{
+    if (mLayerManager &&
+        mLayerManager->GetBackendType() == LayerManager::LAYERS_OPENGL) {
+        // We directly map the hardware fb on Gonk.  The hardware fb
+        // has RGB format.
+        return LOCAL_GL_RGB;
+    }
+    return LOCAL_GL_NONE;
+}

widget/gonk/nsWindow.h

@@ -126,6 +126,8 @@ public:
                                       const InputContextAction& aAction);
     NS_IMETHOD_(InputContext) GetInputContext();
 
+    virtual PRUint32 GetGLFrameBufferFormat() MOZ_OVERRIDE;
+
 protected:
     nsWindow* mParent;
     bool mVisible;

widget/nsIWidget.h

@@ -1510,6 +1510,12 @@ class nsIWidget : public nsISupports {
      *                   parent widget
      */
     NS_IMETHOD ReparentNativeWidget(nsIWidget* aNewParent) = 0;
+
+    /**
+     * Return the internal format of the default framebuffer for this
+     * widget.
+     */
+    virtual PRUint32 GetGLFrameBufferFormat() { return 0; /*GL_NONE*/ }
 protected:
 
     // keep the list of children.  We also keep track of our siblings.

widget/xpwidgets/nsBaseWidget.cpp

@@ -1259,6 +1259,18 @@ nsBaseWidget::BeginMoveDrag(nsMouseEvent* aEvent)
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
+PRUint32
+nsBaseWidget::GetGLFrameBufferFormat()
+{
+  if (mLayerManager &&
+      mLayerManager->GetBackendType() == LayerManager::LAYERS_OPENGL) {
+    // Assume that the default framebuffer has RGBA format.  Specific
+    // backends that know differently will override this method.
+    return LOCAL_GL_RGBA;
+  }
+  return LOCAL_GL_NONE;
+}
+
 #ifdef DEBUG
 //////////////////////////////////////////////////////////////
 //

widget/xpwidgets/nsBaseWidget.h

@@ -201,6 +201,9 @@ public:
   }
 
   NS_IMETHOD              ReparentNativeWidget(nsIWidget* aNewParent) = 0;
+
+  virtual PRUint32 GetGLFrameBufferFormat() MOZ_OVERRIDE;
+
   /**
    * Use this when GetLayerManager() returns a BasicLayerManager
    * (nsBaseWidget::GetLayerManager() does). This sets up the widget's