cc: Main thread skip single layers instead of subtrees

cc/trees/draw_property_utils.cc

 // Copyright 2014 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/trees/draw_property_utils.h"
 
 #include <stddef.h>
 
 #include <vector>
 
@@ skipping 281 matching lines @@
 
   // We use layer's transform to determine back face visibility when its the
   // root of a new rendering context.
   return layer->transform().IsBackFaceVisible();
 }
 
 static inline bool TransformToScreenIsKnown(Layer* layer,
                                             int transform_tree_index,
                                             const TransformTree& tree) {
   const TransformNode* node = tree.Node(transform_tree_index);
-  return !node->data.to_screen_is_animated;
+  return !node->data.to_screen_is_potentially_animated;
 }
 
 static inline bool TransformToScreenIsKnown(LayerImpl* layer,
                                             int transform_tree_index,
                                             const TransformTree& tree) {
   return true;
 }
 
 template <typename LayerType>
 static bool HasInvertibleOrAnimatedTransform(LayerType* layer) {
   return layer->transform_is_invertible() ||
          layer->HasPotentiallyRunningTransformAnimation();
 }
 
-static inline bool SubtreeShouldBeSkipped(Layer* layer,
-                                          bool layer_is_drawn,
-                                          const TransformTree& tree) {
-  // If the layer transform is not invertible, it should not be drawn.
-  if (!layer->transform_is_invertible() &&
-      !layer->HasPotentiallyRunningTransformAnimation())
-    return true;
-
-  // When we need to do a readback/copy of a layer's output, we can not skip
-  // it or any of its ancestors.
-  if (layer->num_copy_requests_in_target_subtree() > 0)
-    return false;
-
-  // If the layer is not drawn, then skip it and its subtree.
-  if (!layer_is_drawn)
-    return true;
-
-  if (layer->has_render_surface() && !layer->double_sided() &&
-      !layer->HasPotentiallyRunningTransformAnimation() &&
-      IsSurfaceBackFaceVisible(layer, tree))
-    return true;
-
-  // If layer has a background filter, don't skip the layer, even it the
-  // opacity is 0.
-  if (!layer->background_filters().IsEmpty())
-    return false;
-
-  // If the opacity is being animated then the opacity on the main thread is
-  // unreliable (since the impl thread may be using a different opacity), so it
-  // should not be trusted.
-  // In particular, it should not cause the subtree to be skipped.
-  // Similarly, for layers that might animate opacity using an impl-only
-  // animation, their subtree should also not be skipped.
-  return !layer->EffectiveOpacity() &&
-         !layer->HasPotentiallyRunningOpacityAnimation() &&
-         !layer->OpacityCanAnimateOnImplThread();
-}
-
 template <typename LayerType>
 static bool LayerNeedsUpdateInternal(LayerType* layer,
                                      bool layer_is_drawn,
                                      const TransformTree& tree) {
   // Layers can be skipped if any of these conditions are met.
   //   - is not drawn due to it or one of its ancestors being hidden (or having
   //     no copy requests).
   //   - does not draw content.
   //   - is transparent.
   //   - has empty bounds
@@ skipping 22 matching lines @@
     // backface is not visible.
     if (TransformToScreenIsKnown(layer, backface_transform_id, tree) &&
         !HasSingularTransform(backface_transform_id, tree) &&
         IsLayerBackFaceVisible(layer, backface_transform_id, tree))
       return false;
   }
 
   return true;
 }
 
-void FindLayersThatNeedUpdates(LayerImpl* layer,
+void FindLayersThatNeedUpdates(LayerTreeImpl* layer_tree_impl,
                                const TransformTree& transform_tree,
                                const EffectTree& effect_tree,
                                LayerImplList* update_layer_list,
                                std::vector<LayerImpl*>* visible_layer_list) {
-  DCHECK_GE(layer->effect_tree_index(), 0);
-  for (auto* layer_impl : *layer->layer_tree_impl()) {
+  for (auto* layer_impl : *layer_tree_impl) {
     bool layer_is_drawn =
-        effect_tree.Node(layer->effect_tree_index())->data.is_drawn;
+        effect_tree.Node(layer_impl->effect_tree_index())->data.is_drawn;
 
     if (!IsRootLayer(layer_impl) &&
-        LayerShouldBeSkipped(layer_impl, layer_is_drawn, transform_tree))
+        LayerShouldBeSkipped(layer_impl, layer_is_drawn, transform_tree,
+                             effect_tree))
       continue;
 
     if (LayerNeedsUpdate(layer_impl, layer_is_drawn, transform_tree)) {
       visible_layer_list->push_back(layer_impl);
       update_layer_list->push_back(layer_impl);
     }
 
-    if (LayerImpl* mask_layer = layer->mask_layer())
+    if (LayerImpl* mask_layer = layer_impl->mask_layer())
       update_layer_list->push_back(mask_layer);
-    if (LayerImpl* replica_layer = layer->replica_layer()) {
+    if (LayerImpl* replica_layer = layer_impl->replica_layer()) {
       if (LayerImpl* mask_layer = replica_layer->mask_layer())
         update_layer_list->push_back(mask_layer);
     }
   }
 }
 
 template <typename LayerType>
 void UpdateRenderSurfaceForLayer(EffectTree* effect_tree,
                                  bool non_root_surfaces_enabled,
                                  LayerType* layer) {
@@ skipping 13 matching lines @@
                                             Layer* layer) {
   UpdateRenderSurfaceForLayer(effect_tree, true, layer);
 
   for (size_t i = 0; i < layer->children().size(); ++i) {
     UpdateRenderSurfacesForLayersRecursive(effect_tree, layer->child_at(i));
   }
 }
 
 }  // namespace
 
+static inline bool LayerShouldBeSkipped(Layer* layer,
+                                        bool layer_is_drawn,
+                                        const TransformTree& transform_tree,
+                                        const EffectTree& effect_tree) {
+  const TransformNode* transform_node =
+      transform_tree.Node(layer->transform_tree_index());
+  const EffectNode* effect_node = effect_tree.Node(layer->effect_tree_index());
+
+  // If the layer transform is not invertible, it should not be drawn.
+  bool has_inherited_invertible_or_animated_transform =
+      (transform_node->data.is_invertible &&
+       transform_node->data.ancestors_are_invertible) ||
+      transform_node->data.to_screen_is_potentially_animated;
+  if (!has_inherited_invertible_or_animated_transform)
+    return true;
+
+  // When we need to do a readback/copy of a layer's output, we can not skip
+  // it or any of its ancestors.
+  if (effect_node->data.num_copy_requests_in_subtree > 0)
+    return false;
+
+  // If the layer is not drawn, then skip it and its subtree.
+  if (!effect_node->data.is_drawn)
+    return true;
+
+  if (!transform_node->data.to_screen_is_potentially_animated &&
+      effect_node->data.hidden_by_backface_visibility)
+    return true;
+
+  // If layer has a background filter, don't skip the layer, even it the
+  // opacity is 0.
+  if (effect_node->data.node_or_ancestor_has_background_filters)
+    return false;
+
+  // If the opacity is being animated then the opacity on the main thread is
+  // unreliable (since the impl thread may be using a different opacity), so it
+  // should not be trusted.
+  // In particular, it should not cause the subtree to be skipped.
+  // Similarly, for layers that might animate opacity using an impl-only
+  // animation, their subtree should also not be skipped.
+  return !effect_node->data.screen_space_opacity &&
+         !effect_node->data.to_screen_opacity_is_animated;
+  //! effect_node->data.to_screen_opacity_can_animate_on_impl;

[ajuma, 2016/04/07 18:46:47]

Nit: this line should be deleted

+}
+
+bool LayerShouldBeSkipped(LayerImpl* layer,
+                          bool layer_is_drawn,
+                          const TransformTree& transform_tree,
+                          const EffectTree& effect_tree) {
+  const TransformNode* transform_node =
+      transform_tree.Node(layer->transform_tree_index());
+  const EffectNode* effect_node = effect_tree.Node(layer->effect_tree_index());
+  // If the layer transform is not invertible, it should not be drawn.
+  // TODO(ajuma): Correctly process subtrees with singular transform for the
+  // case where we may animate to a non-singular transform and wish to
+  // pre-raster.
+  bool has_inherited_invertible_or_animated_transform =
+      (transform_node->data.is_invertible &&
+       transform_node->data.ancestors_are_invertible) ||
+      transform_node->data.to_screen_is_potentially_animated;
+  if (!has_inherited_invertible_or_animated_transform)
+    return true;
+
+  // When we need to do a readback/copy of a layer's output, we can not skip
+  // it or any of its ancestors.
+  if (effect_node->data.num_copy_requests_in_subtree > 0)
+    return false;
+
+  // If the layer is not drawn, then skip it and its subtree.
+  if (!effect_node->data.is_drawn)
+    return true;
+
+  if (effect_node->data.hidden_by_backface_visibility)
+    return true;
+
+  // If layer is on the pending tree and opacity is being animated then
+  // this subtree can't be skipped as we need to create, prioritize and
+  // include tiles for this layer when deciding if tree can be activated.
+  if (!transform_tree.property_trees()->is_active &&
+      effect_node->data.to_screen_opacity_is_animated)
+    return false;
+
+  // If layer has a background filter, don't skip the layer, even it the
+  // opacity is 0.
+  if (effect_node->data.node_or_ancestor_has_background_filters)
+    return false;
+
+  // The opacity of a layer always applies to its children (either implicitly
+  // via a render surface or explicitly if the parent preserves 3D), so the
+  // entire subtree can be skipped if this layer is fully transparent.
+  return !effect_node->data.screen_space_opacity;
+}
+
+void FindLayersThatNeedUpdates(LayerTreeHost* layer_tree_host,
+                               const TransformTree& transform_tree,
+                               const EffectTree& effect_tree,
+                               LayerList* update_layer_list) {
+  LayerTreeHostCommon::CallFunctionForEveryLayer(
+      layer_tree_host,
+      [&](Layer* layer) {
+        bool layer_is_drawn =
+            effect_tree.Node(layer->effect_tree_index())->data.is_drawn;
+
+        if (!IsRootLayer(layer) &&
+            LayerShouldBeSkipped(layer, layer_is_drawn, transform_tree,
+                                 effect_tree))
+          return;
+
+        if (LayerNeedsUpdate(layer, layer_is_drawn, transform_tree)) {
+          update_layer_list->push_back(layer);
+        }
+
+        // Append mask layers to the update layer list.  They don't have valid
+        // visible
+        // rects, so need to get added after the above calculation.  Replica
+        // layers
+        // don't need to be updated.
+        if (Layer* mask_layer = layer->mask_layer())
+          update_layer_list->push_back(mask_layer);
+        if (Layer* replica_layer = layer->replica_layer()) {
+          if (Layer* mask_layer = replica_layer->mask_layer())
+            update_layer_list->push_back(mask_layer);
+        }
+      },
+      CallFunctionLayerType::BASIC_LAYER);
+}
+
 static void ResetIfHasNanCoordinate(gfx::RectF* rect) {
   if (std::isnan(rect->x()) || std::isnan(rect->y()) ||
       std::isnan(rect->right()) || std::isnan(rect->bottom()))
     *rect = gfx::RectF();
 }
 
 void ComputeClips(ClipTree* clip_tree,
                   const TransformTree& transform_tree,
                   bool non_root_surfaces_enabled) {
   if (!clip_tree->needs_update())
@@ skipping 158 matching lines @@
     property_trees->non_root_surfaces_enabled = can_render_to_separate_surface;
     property_trees->transform_tree.set_needs_update(true);
   }
   if (property_trees->transform_tree.needs_update())
     property_trees->clip_tree.set_needs_update(true);
   ComputeTransforms(&property_trees->transform_tree);
   ComputeClips(&property_trees->clip_tree, property_trees->transform_tree,
                can_render_to_separate_surface);
   ComputeEffects(&property_trees->effect_tree);
 
-  FindLayersThatNeedUpdates(root_layer, property_trees->transform_tree,
-                            property_trees->effect_tree, update_layer_list,
-                            visible_layer_list);
+  FindLayersThatNeedUpdates(
+      root_layer->layer_tree_impl(), property_trees->transform_tree,
+      property_trees->effect_tree, update_layer_list, visible_layer_list);
   CalculateVisibleRects<LayerImpl>(
       *visible_layer_list, property_trees->clip_tree,
       property_trees->transform_tree, can_render_to_separate_surface);
 }
 
 void UpdateRenderSurfaces(Layer* root_layer, PropertyTrees* property_trees) {
   UpdateRenderSurfacesForLayersRecursive(&property_trees->effect_tree,
                                          root_layer);
 #if DCHECK_IS_ON()
   ValidateRenderSurfacesRecursive(root_layer);
 #endif
 }
 
 void UpdatePropertyTrees(PropertyTrees* property_trees,
                          bool can_render_to_separate_surface) {
   if (property_trees->non_root_surfaces_enabled !=
       can_render_to_separate_surface) {
     property_trees->non_root_surfaces_enabled = can_render_to_separate_surface;
     property_trees->transform_tree.set_needs_update(true);
   }
   if (property_trees->transform_tree.needs_update())
     property_trees->clip_tree.set_needs_update(true);
   ComputeTransforms(&property_trees->transform_tree);
   ComputeClips(&property_trees->clip_tree, property_trees->transform_tree,
                can_render_to_separate_surface);
   ComputeEffects(&property_trees->effect_tree);
 }
 
-void FindLayersThatNeedUpdates(Layer* layer,
-                               const TransformTree& transform_tree,
-                               const EffectTree& effect_tree,
-                               LayerList* update_layer_list) {
-  DCHECK_GE(layer->effect_tree_index(), 0);
-  bool layer_is_drawn =
-      effect_tree.Node(layer->effect_tree_index())->data.is_drawn;
-
-  if (!IsRootLayer(layer) &&
-      SubtreeShouldBeSkipped(layer, layer_is_drawn, transform_tree))
-    return;
-
-  if (LayerNeedsUpdate(layer, layer_is_drawn, transform_tree))
-    update_layer_list->push_back(layer);
-  if (Layer* mask_layer = layer->mask_layer())
-    update_layer_list->push_back(mask_layer);
-  if (Layer* replica_layer = layer->replica_layer()) {
-    if (Layer* mask_layer = replica_layer->mask_layer())
-      update_layer_list->push_back(mask_layer);
-  }
-
-  for (size_t i = 0; i < layer->children().size(); ++i) {
-    FindLayersThatNeedUpdates(layer->child_at(i), transform_tree, effect_tree,
-                              update_layer_list);
-  }
-}
-
 void ComputeVisibleRectsForTesting(PropertyTrees* property_trees,
                                    bool can_render_to_separate_surface,
                                    LayerList* update_layer_list) {
   CalculateVisibleRects<Layer>(*update_layer_list, property_trees->clip_tree,
                                property_trees->transform_tree,
                                can_render_to_separate_surface);
 }
 
 void BuildPropertyTreesAndComputeVisibleRects(
     LayerImpl* root_layer,
@@ skipping 29 matching lines @@
     if (can_render_to_separate_surface)
       ValidateRenderSurfaceForLayer(layer);
 #endif
   }
   LayerImplList update_layer_list;
   ComputeVisibleRectsInternal(root_layer, property_trees,
                               can_render_to_separate_surface,
                               &update_layer_list, visible_layer_list);
 }
 
-bool LayerShouldBeSkipped(LayerImpl* layer,
-                          bool layer_is_drawn,
-                          const TransformTree& transform_tree) {
-  const TransformNode* transform_node =
-      transform_tree.Node(layer->transform_tree_index());
-  const EffectTree& effect_tree = transform_tree.property_trees()->effect_tree;
-  const EffectNode* effect_node = effect_tree.Node(layer->effect_tree_index());
-  // If the layer transform is not invertible, it should not be drawn.
-  // TODO(ajuma): Correctly process subtrees with singular transform for the
-  // case where we may animate to a non-singular transform and wish to
-  // pre-raster.
-  bool has_inherited_invertible_or_animated_transform =
-      (transform_node->data.is_invertible &&
-       transform_node->data.ancestors_are_invertible) ||
-      transform_node->data.to_screen_is_animated;
-  if (!has_inherited_invertible_or_animated_transform)
-    return true;
-
-  // When we need to do a readback/copy of a layer's output, we can not skip
-  // it or any of its ancestors.
-  if (effect_node->data.num_copy_requests_in_subtree > 0)
-    return false;
-
-  // If the layer is not drawn, then skip it and its subtree.
-  if (!effect_node->data.is_drawn)
-    return true;
-
-  if (effect_node->data.hidden_by_backface_visibility)
-    return true;
-
-  // If layer is on the pending tree and opacity is being animated then
-  // this subtree can't be skipped as we need to create, prioritize and
-  // include tiles for this layer when deciding if tree can be activated.
-  if (!transform_tree.property_trees()->is_active &&
-      effect_node->data.to_screen_opacity_is_animated)
-    return false;
-
-  // If layer has a background filter, don't skip the layer, even it the
-  // opacity is 0.
-  if (effect_node->data.node_or_ancestor_has_background_filters)
-    return false;
-
-  // The opacity of a layer always applies to its children (either implicitly
-  // via a render surface or explicitly if the parent preserves 3D), so the
-  // entire subtree can be skipped if this layer is fully transparent.
-  return !effect_node->data.screen_space_opacity;
-}
-
 bool LayerNeedsUpdate(Layer* layer,
                       bool layer_is_drawn,
                       const TransformTree& tree) {
   return LayerNeedsUpdateInternal(layer, layer_is_drawn, tree);
 }
 
 bool LayerNeedsUpdate(LayerImpl* layer,
                       bool layer_is_drawn,
                       const TransformTree& tree) {
   return LayerNeedsUpdateInternal(layer, layer_is_drawn, tree);
@@ skipping 217 matching lines @@
   layer->draw_properties().screen_space_transform =
       ScreenSpaceTransformInternal(layer, transform_node);
   if (property_trees->non_root_surfaces_enabled) {
     layer->draw_properties().target_space_transform =
         DrawTransform(layer, property_trees->transform_tree);
   } else {
     layer->draw_properties().target_space_transform =
         layer->draw_properties().screen_space_transform;
   }
   layer->draw_properties().screen_space_transform_is_animating =
-      transform_node->data.to_screen_is_animated;
+      transform_node->data.to_screen_is_potentially_animated;
   if (layer->layer_tree_impl()
           ->settings()
           .layer_transforms_should_scale_layer_contents) {
     layer->draw_properties().maximum_animation_contents_scale =
         transform_node->data.combined_maximum_animation_target_scale;
     layer->draw_properties().starting_animation_contents_scale =
         transform_node->data.combined_starting_animation_scale;
   } else {
     layer->draw_properties().maximum_animation_contents_scale = 0.f;
     layer->draw_properties().starting_animation_contents_scale = 0.f;
@@ skipping 132 matching lines @@
 void UpdateElasticOverscroll(PropertyTrees* property_trees,
                              const Layer* overscroll_elasticity_layer,
                              const gfx::Vector2dF& elastic_overscroll) {
   UpdateElasticOverscrollInternal(property_trees, overscroll_elasticity_layer,
                                   elastic_overscroll);
 }
 
 }  // namespace draw_property_utils
 
 }  // namespace cc