Introduce Property Trees

cc/trees/draw_property_utils.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_DRAW_PROPERTY_UTILS_H_
+#define CC_TREES_DRAW_PROPERTY_UTILS_H_
+
+#include "cc/base/cc_export.h"
+
+namespace gfx {
+class Rect;
+class Transform;
+}  // namespace gfx
+
+namespace cc {
+
+class Layer;
+
+struct ClipNodeData;
+struct TransformNodeData;
+
+template <typename T>
+struct TreeNode;
+
+template <typename T>
+class PropertyTree;
+
+// Computes combined clips for every node in |clip_tree|. This function requires
+// that |transform_tree| has been updated via |ComputeTransforms|.
+// TODO(vollick): ComputeClips and ComputeTransforms will eventually need to be
+// done on both threads.
+void CC_EXPORT
+ComputeClips(PropertyTree<TreeNode<ClipNodeData>>* clip_tree,
+             const PropertyTree<TreeNode<TransformNodeData>>& transform_tree);
+
+// Computes combined (screen space) transforms for every node in the transform
+// tree. This must be done prior to calling |ComputeClips|.
+void CC_EXPORT
+ComputeTransforms(PropertyTree<TreeNode<TransformNodeData>>* transform_tree);
+
+// Computes the visible content rect for every layer under |root_layer|. The
+// visible content rect is the clipped content space rect that will be used for
+// recording.
+void CC_EXPORT ComputeVisibleRectsUsingPropertyTrees(
+    Layer* root_layer,
+    const Layer* page_scale_layer,
+    float page_scale_factor,
+    float device_scale_factor,
+    const gfx::Rect& viewport,
+    const gfx::Transform& device_transform,
+    PropertyTree<TreeNode<TransformNodeData>>* transform_tree,
+    PropertyTree<TreeNode<ClipNodeData>>* clip_tree);
+
+}  // namespace cc
+
+#endif  // CC_TREES_DRAW_PROPERTY_UTILS_H_