Introduce Property Trees

cc/trees/property_tree.h

Index: cc/trees/property_tree.h
diff --git a/cc/trees/property_tree.h b/cc/trees/property_tree.h
new file mode 100644
index 0000000000000000000000000000000000000000..cc502a8ba1ceab0bd409771c98cd527cce23de0c
--- /dev/null
+++ b/cc/trees/property_tree.h
@@ -0,0 +1,107 @@
+// 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 <vector>
+
+#include "base/basictypes.h"
+#include "cc/base/cc_export.h"
+#include "ui/gfx/rect.h"
+#include "ui/gfx/transform.h"
+
+namespace cc {
+
+template <typename T>
+struct CC_EXPORT TreeNode {
+  TreeNode() : id(-1), parent_id(-1), data() {}
+  int id;
+  int parent_id;
+  T data;
+};
+
+struct CC_EXPORT TransformNodeData {
+  TransformNodeData();
+  ~TransformNodeData();
+
+  gfx::Transform to_parent;
+  gfx::Transform from_parent;
+
+  gfx::Transform to_screen;
+  gfx::Transform from_screen;
+
+  int target_id;
+
+  bool is_invertible;
+  bool ancestors_are_invertible;
+  bool flattens;
+
+  void set_to_parent(const gfx::Transform& transform) {
+    to_parent = transform;
+    is_invertible = to_parent.GetInverse(&from_parent);
+  }
+};
+
+typedef TreeNode<TransformNodeData> TransformNode;
+
+struct CC_EXPORT ClipNodeData {
+  ClipNodeData();
+
+  gfx::RectF clip;
+  gfx::RectF combined_clip;
+  int transform_id;
+  int target_id;
+};
+
+typedef TreeNode<ClipNodeData> ClipNode;
+
+template <typename T>
+class CC_EXPORT PropertyTree {
+ public:
+  PropertyTree();
+  // Not virtual. Should not derive from this class.

[enne (OOO), 2014/12/10 23:45:59]

final?

[Ian Vollick, 2014/12/12 03:01:47]

Done.

+  ~PropertyTree();
+
+  int Insert(const T& tree_node, int parent_id);
+
+  T* Node(int i) { return i > -1 ? &nodes_[i] : nullptr; }
+  const T* Node(int i) const { return i > -1 ? &nodes_[i] : nullptr; }
+
+  T* parent(const T* t) {
+    return t->parent_id > -1 ? Node(t->parent_id) : nullptr;
+  }
+  const T* parent(const T* t) const {
+    return t->parent_id > -1 ? Node(t->parent_id) : nullptr;
+  }
+
+  T* back() { return size() ? &nodes_[nodes_.size() - 1] : nullptr; }
+  const T* back() const {
+    return size() ? &nodes_[nodes_.size() - 1] : nullptr;
+  }
+
+  void clear() { nodes_.clear(); }
+  size_t size() const { return nodes_.size(); }
+
+ private:
+  // Copy and assign are permitted. This is how we'll do tree sync.
+  std::vector<T> nodes_;
+};
+
+typedef PropertyTree<TransformNode> TransformTree;
+typedef PropertyTree<ClipNode> ClipTree;
+
+bool CC_EXPORT ComputeTransform(const TransformTree& tree,

[enne (OOO), 2014/12/10 23:45:59]

Make this a const function on TransformTree?

[Ian Vollick, 2014/12/12 03:01:47]

Done.

+                                int source_id,
+                                int dest_id,
+                                gfx::Transform* transform);
+
+bool CC_EXPORT
+Are2DAxisAligned(const TransformTree& tree, int source_id, int dest_id);

[enne (OOO), 2014/12/10 23:45:59]

Same here?

[Ian Vollick, 2014/12/12 03:01:47]

Done.

+
+void CC_EXPORT UpdateScreenSpaceTransform(TransformTree* tree, int id);
+
+}  // namespace cc
+
+#endif  // CC_TREES_PROPERTY_TREE_H_