cc: Compute animation scale on demand

cc/trees/property_tree.h

 // 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.
 
 #ifndef CC_TREES_PROPERTY_TREE_H_
 #define CC_TREES_PROPERTY_TREE_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 102 matching lines @@
 
   bool node_and_ancestors_are_animated_or_invertible : 1;
 
   bool is_invertible : 1;
   bool ancestors_are_invertible : 1;
 
   bool has_potential_animation : 1;
   bool is_currently_animating : 1;
   bool to_screen_is_potentially_animated : 1;
   bool has_only_translation_animations : 1;
-  bool to_screen_has_scale_animation : 1;
 
   // Flattening, when needed, is only applied to a node's inherited transform,
   // never to its local transform.
   bool flattens_inherited_transform : 1;
 
   // This is true if the to_parent transform at every node on the path to the
   // root is flat.
   bool node_and_ancestors_are_flat : 1;
 
   // This is needed to know if a layer can use lcd text.
@@ skipping 15 matching lines @@
   // space transform. For layers in the subtree of the page scale layer, the
   // layer scale factor should include the page scale factor.
   bool in_subtree_of_page_scale_layer : 1;
 
   // We need to track changes to to_screen transform to compute the damage rect.
   bool transform_changed : 1;
 
   // TODO(vollick): will be moved when accelerated effects are implemented.
   float post_local_scale_factor;
 
-  // The maximum scale that that node's |local| transform will have during
-  // current animations, considering only scales at keyframes not including the
-  // starting keyframe of each animation.
-  float local_maximum_animation_target_scale;
-
-  // The maximum scale that this node's |local| transform will have during
-  // current animatons, considering only the starting scale of each animation.
-  float local_starting_animation_scale;
-
-  // The maximum scale that this node's |to_target| transform will have during
-  // current animations, considering only scales at keyframes not incuding the
-  // starting keyframe of each animation.
-  float combined_maximum_animation_target_scale;
-
-  // The maximum scale that this node's |to_target| transform will have during
-  // current animations, considering only the starting scale of each animation.
-  float combined_starting_animation_scale;
-
   gfx::Vector2dF sublayer_scale;
 
   // TODO(vollick): will be moved when accelerated effects are implemented.
   gfx::ScrollOffset scroll_offset;
 
   // We scroll snap where possible, but this means fixed-pos elements must be
   // adjusted.  This value stores the snapped amount for this purpose.
   gfx::Vector2dF scroll_snap;
 
   // TODO(vollick): will be moved when accelerated effects are implemented.
@@ skipping 11 matching lines @@
 
   void update_post_local_transform(const gfx::PointF& position,
                                    const gfx::Point3F& transform_origin);
 
   void ToProtobuf(proto::TreeNode* proto) const;
   void FromProtobuf(const proto::TreeNode& proto);
 
   void AsValueInto(base::trace_event::TracedValue* value) const;
 };
 
+// TODO(sunxd): move this into PropertyTrees::cached_data_.
 struct CC_EXPORT TransformCachedNodeData {
   TransformCachedNodeData();
   TransformCachedNodeData(const TransformCachedNodeData& other);
   ~TransformCachedNodeData();
 
   gfx::Transform from_target;
   gfx::Transform to_target;
   gfx::Transform from_screen;
   gfx::Transform to_screen;
   int target_id;
@@ skipping 502 matching lines @@
   ScrollOffsetMap layer_id_to_scroll_offset_map_;
 
   SyncedScrollOffset* synced_scroll_offset(int layer_id);
   const SyncedScrollOffset* synced_scroll_offset(int layer_id) const;
   gfx::ScrollOffset PullDeltaForMainThread(SyncedScrollOffset* scroll_offset);
   void UpdateScrollOffsetMapEntry(int key,
                                   ScrollOffsetMap* new_scroll_offset_map,
                                   LayerTreeImpl* layer_tree_impl);
 };
 
+struct AnimationScaleData {
+  // Variable used to invalidate cached animation scale data when transform tree
+  // updates.
+  int update_number;
+
+  // Current animations, considering only scales at keyframes not including the
+  // starting keyframe of each animation.
+  float local_maximum_animation_target_scale;
+
+  // The maximum scale that this node's |local| transform will have during
+  // current animatons, considering only the starting scale of each animation.
+  float local_starting_animation_scale;
+
+  // The maximum scale that this node's |to_target| transform will have during
+  // current animations, considering only scales at keyframes not incuding the
+  // starting keyframe of each animation.
+  float combined_maximum_animation_target_scale;
+
+  // The maximum scale that this node's |to_target| transform will have during
+  // current animations, considering only the starting scale of each animation.
+  float combined_starting_animation_scale;
+
+  bool to_screen_has_scale_animation;
+
+  AnimationScaleData() {
+    update_number = -1;
+    local_maximum_animation_target_scale = 0.f;
+    local_starting_animation_scale = 0.f;
+    combined_maximum_animation_target_scale = 0.f;
+    combined_starting_animation_scale = 0.f;
+    to_screen_has_scale_animation = false;
+  }
+};
+
+struct CombinedAnimationScale {
+  float maximum_animation_scale;
+  float starting_animation_scale;
+
+  CombinedAnimationScale(float maximum, float starting)
+      : maximum_animation_scale(maximum), starting_animation_scale(starting) {}
+  bool operator==(const CombinedAnimationScale& other) const {
+    return maximum_animation_scale == other.maximum_animation_scale &&
+           starting_animation_scale == other.starting_animation_scale;
+  }
+};
+
+struct PropertyTreesCachedData {
+  int property_tree_update_number;
+  std::vector<AnimationScaleData> animation_scales;
+
+  PropertyTreesCachedData();
+  ~PropertyTreesCachedData();
+};
+
 class CC_EXPORT PropertyTrees final {
  public:
   PropertyTrees();
   PropertyTrees(const PropertyTrees& other) = delete;
   ~PropertyTrees();
 
   bool operator==(const PropertyTrees& other) const;
   PropertyTrees& operator=(const PropertyTrees& from);
 
   void ToProtobuf(proto::PropertyTrees* proto) const;
@@ skipping 44 matching lines @@
   gfx::Vector2dF outer_viewport_container_bounds_delta() const {
     return outer_viewport_container_bounds_delta_;
   }
 
   gfx::Vector2dF inner_viewport_scroll_bounds_delta() const {
     return inner_viewport_scroll_bounds_delta_;
   }
 
   std::unique_ptr<base::trace_event::TracedValue> AsTracedValue() const;
 
+  CombinedAnimationScale GetAnimationScales(int transform_node_id,
+                                            LayerTreeImpl* layer_tree_impl);
+  void SetAnimationScalesForTesting(int transform_id,
+                                    float maximum_animation_scale,
+                                    float starting_animation_scale);
+  void ResetCachedData();
+  void UpdateCachedNumber();
+
  private:
   gfx::Vector2dF inner_viewport_container_bounds_delta_;
   gfx::Vector2dF outer_viewport_container_bounds_delta_;
   gfx::Vector2dF inner_viewport_scroll_bounds_delta_;
+
+  PropertyTreesCachedData cached_data_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_PROPERTY_TREE_H_