cc : Split TransformTree::ComputeTransform

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 136 matching lines @@
   // be computed between any pair of nodes that have an ancestor/descendant
   // relationship. Transforms between other pairs of nodes may only be computed
   // if the following condition holds: let id1 the larger id and let id2 be the
   // other id; then the nearest ancestor of node id1 whose id is smaller than
   // id2 is the lowest common ancestor of the pair of nodes, and the transform
   // from this lowest common ancestor to node id2 is only a 2d translation.
   bool ComputeTransform(int source_id,
                         int dest_id,
                         gfx::Transform* transform) const;
 
+  // Computes the change of basis transform from node |source_id| to |dest_id|.
+  // This is used by scroll children to compute transform from their scroll
+  // parent space (source) to their parent space (destination) and it can atmost
+  // be a translation.
+  bool ComputeTranslation(int source_id,
+                          int dest_id,
+                          gfx::Transform* transform) const;
+
   void ResetChangeTracking();
   // Updates the parent, target, and screen space transforms and snapping.
   void UpdateTransforms(int id);
   void UpdateTransformChanged(TransformNode* node,
                               TransformNode* parent_node,
                               TransformNode* source_node);
   void UpdateNodeAndAncestorsAreAnimatedOrInvertible(
       TransformNode* node,
       TransformNode* parent_node);
 
@@ skipping 71 matching lines @@
   void SetContentTargetId(int node_id, int content_target_id);
 
   const std::vector<TransformCachedNodeData>& cached_data() const {
     return cached_data_;
   }
 
   void ToProtobuf(proto::PropertyTree* proto) const;
   void FromProtobuf(const proto::PropertyTree& proto,
                     std::unordered_map<int, int>* node_id_to_index_map);
 
-  // Computes the combined transform between |source_id| and |dest_id| and
-  // returns false if the inverse of a singular transform was used. These two
-  // nodes must be on the same ancestor chain.
-  bool CombineTransformsBetween(int source_id,
+  // Computes the combined transform between |source_id| and |dest_id|. These
+  // two nodes must be on the same ancestor chain.
+  void CombineTransformsBetween(int source_id,
                                 int dest_id,
                                 gfx::Transform* transform) const;
 
   // Computes the combined inverse transform between |source_id| and |dest_id|
   // and returns false if the inverse of a singular transform was used. These
   // two nodes must be on the same ancestor chain.
   bool CombineInversesBetween(int source_id,
                               int dest_id,
                               gfx::Transform* transform) const;
 
@@ skipping 322 matching lines @@
 
   void ResetCachedData();
   void UpdateCachedNumber();
   gfx::Transform ToScreenSpaceTransformWithoutSurfaceContentsScale(
       int transform_id,
       int effect_id) const;
   bool ComputeTransformToTarget(int transform_id,
                                 int effect_id,
                                 gfx::Transform* transform) const;
 
+  bool ComputeTransformFromTarget(int transform_id,
+                                  int effect_id,
+                                  gfx::Transform* transform) const;
+
  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_