Bug 1113435 - Only cull the fully rendered region when doing progressive draw. r=jrmuizel

--HG--
extra : rebase_source : 063a04e728be38aaf2dc812ead3957c001e61e64

gfx/layers/TiledLayerBuffer.h

@@ -236,6 +236,8 @@ public:
    */
   virtual const nsIntRegion& GetValidLowPrecisionRegion() const = 0;
 
+  virtual const nsIntRegion& GetValidRegion() const = 0;
+
 #if defined(MOZ_WIDGET_GONK) && ANDROID_VERSION >= 17
   /**
    * Store a fence that will signal when the current buffer is no longer being read.

gfx/layers/composite/LayerManagerComposite.cpp

@@ -233,7 +233,7 @@ LayerManagerComposite::ApplyOcclusionCulling(Layer* aLayer, nsIntRegion& aOpaque
       !aLayer->GetMaskLayer() &&
       aLayer->GetLocalOpacity() == 1.0f) {
     if (aLayer->GetContentFlags() & Layer::CONTENT_OPAQUE) {
-      localOpaque.Or(localOpaque, composite->GetShadowVisibleRegion());
+      localOpaque.Or(localOpaque, composite->GetFullyRenderedRegion());
     }
     localOpaque.MoveBy(transform2d._31, transform2d._32);
     const nsIntRect* clip = aLayer->GetEffectiveClipRect();
@@ -1151,6 +1151,20 @@ LayerComposite::SetLayerManager(LayerManagerComposite* aManager)
   mCompositor = aManager->GetCompositor();
 }
 
+nsIntRegion
+LayerComposite::GetFullyRenderedRegion() {
+  if (TiledLayerComposer* tiled = GetTiledLayerComposer()) {
+    nsIntRegion shadowVisibleRegion = GetShadowVisibleRegion();
+    // Discard the region which hasn't been drawn yet when doing
+    // progressive drawing. Note that if the shadow visible region
+    // shrunk the tiled valig region may not have discarded this yet.
+    shadowVisibleRegion.And(shadowVisibleRegion, tiled->GetValidRegion());
+    return shadowVisibleRegion;
+  } else {
+    return GetShadowVisibleRegion();
+  }
+}
+
 #ifndef MOZ_HAVE_PLATFORM_SPECIFIC_LAYER_BUFFERS
 
 /*static*/ bool

gfx/layers/composite/LayerManagerComposite.h

@@ -441,6 +441,13 @@ public:
   bool HasLayerBeenComposited() { return mLayerComposited; }
   nsIntRect GetClearRect() { return mClearRect; }
 
+  /**
+   * Return the part of the visible region that has been fully rendered.
+   * While progressive drawing is in progress this region will be
+   * a subset of the shadow visible region.
+   */
+  nsIntRegion GetFullyRenderedRegion();
+
 protected:
   gfx::Matrix4x4 mShadowTransform;
   nsIntRegion mShadowVisibleRegion;

gfx/layers/composite/TiledContentHost.h

@@ -231,6 +231,11 @@ public:
     return mLowPrecisionTiledBuffer.GetValidRegion();
   }
 
+  const nsIntRegion& GetValidRegion() const MOZ_OVERRIDE
+  {
+    return mTiledBuffer.GetValidRegion();
+  }
+
   virtual void SetCompositor(Compositor* aCompositor) MOZ_OVERRIDE
   {
     CompositableHost::SetCompositor(aCompositor);