mix-blend-mode implementation for accelerated layers

cc/layers/layer.cc

 // Copyright 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/layer.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "base/location.h"
@@ skipping 27 matching lines @@
       ignore_set_needs_commit_(false),
       parent_(NULL),
       layer_tree_host_(NULL),
       scrollable_(false),
       should_scroll_on_main_thread_(false),
       have_wheel_event_handlers_(false),
       anchor_point_(0.5f, 0.5f),
       background_color_(0),
       compositing_reasons_(kCompositingReasonUnknown),
       opacity_(1.f),
+      blend_mode_(SkXfermode::kSrcOver_Mode),
+      is_root_for_isolated_group_(false),
       anchor_point_z_(0.f),
       is_container_for_fixed_position_layers_(false),
       is_drawable_(false),
       hide_layer_and_subtree_(false),
       masks_to_bounds_(false),
       contents_opaque_(false),
       double_sided_(true),
       preserves_3d_(false),
       use_parent_backface_visibility_(false),
       draw_checkerboard_for_missing_tiles_(false),
@@ skipping 58 matching lines @@
   if (host) {
     layer_animation_controller_->SetAnimationRegistrar(
         host->animation_registrar());
 
     if (host->settings().layer_transforms_should_scale_layer_contents)
       reset_raster_scale_to_unknown();
   }
 
   if (host && layer_animation_controller_->has_any_animation())
     host->SetNeedsCommit();
-  if (host && (!filters_.IsEmpty() || !background_filters_.IsEmpty()))
+  if (host && (!filters_.IsEmpty() || !background_filters_.IsEmpty() ||

[enne (OOO), 2013/11/01 18:49:02]

Can you combine all these conditions in a single "SetNeedsFilterContextIfNeeded"
helper that SetLayerTreeHost, all the set filter, and SetBlendMode can call?
That way all of these conditions don't have to be spread around everywhere?

[rosca, 2013/11/04 17:14:34]

Done.

+               !uses_default_blend_mode()))
     layer_tree_host_->set_needs_filter_context();
 }
 
 void Layer::SetNeedsUpdate() {
   if (layer_tree_host_ && !ignore_set_needs_commit_)
     layer_tree_host_->SetNeedsUpdateLayers();
 }
 
 void Layer::SetNeedsCommit() {
   if (!layer_tree_host_)
@@ skipping 359 matching lines @@
 }
 
 bool Layer::OpacityIsAnimating() const {
   return layer_animation_controller_->IsAnimatingProperty(Animation::Opacity);
 }
 
 bool Layer::OpacityCanAnimateOnImplThread() const {
   return false;
 }
 
+void Layer::SetBlendMode(SkXfermode::Mode blend_mode) {
+  if (blend_mode_ == blend_mode)
+    return;
+  blend_mode_ = blend_mode;
+  SetNeedsCommit();
+  if (!uses_default_blend_mode() && layer_tree_host_)
+    layer_tree_host_->set_needs_filter_context();
+}
+
+void Layer::SetIsRootForIsolatedGroup(bool root) {
+  if (is_root_for_isolated_group_ == root)
+    return;
+  is_root_for_isolated_group_ = root;
+  SetNeedsCommit();
+}
+
 void Layer::SetContentsOpaque(bool opaque) {
   DCHECK(IsPropertyChangeAllowed());
   if (contents_opaque_ == opaque)
     return;
   contents_opaque_ = opaque;
   SetNeedsCommit();
 }
 
 void Layer::SetPosition(gfx::PointF position) {
   DCHECK(IsPropertyChangeAllowed());
@@ skipping 297 matching lines @@
   layer->SetBackgroundFilters(background_filters());
   layer->SetMasksToBounds(masks_to_bounds_);
   layer->SetShouldScrollOnMainThread(should_scroll_on_main_thread_);
   layer->SetHaveWheelEventHandlers(have_wheel_event_handlers_);
   layer->SetNonFastScrollableRegion(non_fast_scrollable_region_);
   layer->SetTouchEventHandlerRegion(touch_event_handler_region_);
   layer->SetContentsOpaque(contents_opaque_);
   if (!layer->OpacityIsAnimatingOnImplOnly() && !OpacityIsAnimating())
     layer->SetOpacity(opacity_);
   DCHECK(!(OpacityIsAnimating() && layer->OpacityIsAnimatingOnImplOnly()));
+  layer->SetBlendMode(blend_mode_);
+  layer->SetIsRootForIsolatedGroup(is_root_for_isolated_group_);
   layer->SetPosition(position_);
   layer->SetIsContainerForFixedPositionLayers(
       IsContainerForFixedPositionLayers());
   layer->SetFixedContainerSizeDelta(gfx::Vector2dF());
   layer->SetPositionConstraint(position_constraint_);
   layer->SetPreserves3d(preserves_3d());
   layer->SetUseParentBackfaceVisibility(use_parent_backface_visibility_);
   layer->SetSublayerTransform(sublayer_transform_);
   if (!layer->TransformIsAnimatingOnImplOnly() && !TransformIsAnimating())
     layer->SetTransform(transform_);
@@ skipping 251 matching lines @@
     clip_parent_->RemoveClipChild(this);
 
   clip_parent_ = NULL;
 }
 
 void Layer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 }  // namespace cc