Index: cc/trees/layer_tree_host_common.cc |
diff --git a/cc/trees/layer_tree_host_common.cc b/cc/trees/layer_tree_host_common.cc |
index 0f31038f4990f5920fea4d320e691bfacdb978af..44b13b0f738f903f735cdd90e86ba0709784538e 100644 |
--- a/cc/trees/layer_tree_host_common.cc |
+++ b/cc/trees/layer_tree_host_common.cc |
@@ -587,6 +587,33 @@ static bool SubtreeShouldRenderToSeparateSurface( |
return true; |
} |
+ // If the layer has blending. |
+ // TODO(rosca): this is temporary, until blending is implemented for other |
+ // types of quads than RenderPassQuad. Layers having descendants that draw |
+ // content will still create a separate rendering surface. |
+ if (!layer->uses_default_blend_mode()) { |
+ TRACE_EVENT_INSTANT0( |
+ "cc", |
+ "LayerTreeHostCommon::SubtreeShouldRenderToSeparateSurface blending", |
+ TRACE_EVENT_SCOPE_THREAD); |
+ DCHECK(!is_root); |
+ return true; |
+ } |
+ |
+ // If the layer has isolation. |
+ // TODO(rosca): to be optimized - create separate rendering surface only when |
+ // the blending descendants might have access to the content behind this layer |
+ // (layer has transparent background or descendants overflow) |
+ // https://code.google.com/p/chromium/issues/detail?id=301738 |
+ if (layer->is_root_for_isolated_group()) { |
+ TRACE_EVENT_INSTANT0( |
+ "cc", |
+ "LayerTreeHostCommon::SubtreeShouldRenderToSeparateSurface isolation", |
+ TRACE_EVENT_SCOPE_THREAD); |
+ DCHECK(!is_root); |
enne (OOO)
2013/11/06 22:40:19
Why can't this be the root? In the cases above, we
rosca
2013/11/07 01:58:16
Agree. Done.
|
+ return true; |
+ } |
+ |
// If the layer clips its descendants but it is not axis-aligned with respect |
// to its parent. |
bool layer_clips_external_content = |
@@ -2048,6 +2075,16 @@ static void CalculateDrawPropertiesInternal( |
return; |
} |
+ // Layers having a non-default blend mode will blend with the content |
+ // inside its parent's render target. This render target should be |
+ // either root_for_isolated_group, or the root of the layer tree. |
+ // Otherwise, this layer will use an incomplete backdrop, limited to its |
+ // render target and the blending result will be incorrect. |
+ DCHECK(layer->uses_default_blend_mode() || !layer->parent() || |
+ !layer->parent()->render_target() || |
+ IsRootLayer(layer->parent()->render_target()) || |
+ layer->parent()->render_target()->is_root_for_isolated_group()); |
+ |
render_surface->SetContentRect(clipped_content_rect); |
// The owning layer's screen_space_transform has a scale from content to |