cc/CCLayerSorter.h

   1 // Copyright 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CCLayerSorter_h
   6 #define CCLayerSorter_h
   7
   8 #include "CCLayerImpl.h"
   9 #include "FloatPoint3D.h"
  10 #include "FloatQuad.h"
  11 #include "FloatRect.h"
  12 #include <wtf/HashMap.h>
  13 #include <wtf/Noncopyable.h>
  14 #include <wtf/Vector.h>
  15
  16 namespace WebKit {
  17 class WebTransformationMatrix;
  18 }
  19
  20 namespace WebCore {
  21
  22 class CCLayerSorter {
  23     WTF_MAKE_NONCOPYABLE(CCLayerSorter);
  24 public:
  25     CCLayerSorter() : m_zRange(0) { }
  26
  27     typedef Vector<CCLayerImpl*> LayerList;
  28
  29     void sort(LayerList::iterator first, LayerList::iterator last);
  30
  31     // Holds various useful properties derived from a layer's 3D outline.
  32     struct LayerShape {
  33         LayerShape() { }
  34         LayerShape(float width, float height, const WebKit::WebTransformationMatrix& drawTransform);
  35
  36         float layerZFromProjectedPoint(const FloatPoint&) const;
  37
  38         FloatPoint3D layerNormal;
  39         FloatPoint3D transformOrigin;
  40         FloatQuad projectedQuad;
  41         FloatRect projectedBounds;
  42     };
  43
  44     enum ABCompareResult {
  45         ABeforeB,
  46         BBeforeA,
  47         None
  48     };
  49
  50     static ABCompareResult checkOverlap(LayerShape*, LayerShape*, float zThreshold, float& weight);
  51
  52 private:
  53     struct GraphEdge;
  54
  55     struct GraphNode {
  56         explicit GraphNode(CCLayerImpl* cclayer) : layer(cclayer), incomingEdgeWeight(0) { }
  57
  58         CCLayerImpl* layer;
  59         LayerShape shape;
  60         Vector<GraphEdge*> incoming;
  61         Vector<GraphEdge*> outgoing;
  62         float incomingEdgeWeight;
  63     };
  64
  65     struct GraphEdge {
  66         GraphEdge(GraphNode* fromNode, GraphNode* toNode, float weight) : from(fromNode), to(toNode), weight(weight) { };
  67
  68         GraphNode* from;
  69         GraphNode* to;
  70         float weight;
  71     };
  72
  73     typedef Vector<GraphNode> NodeList;
  74     typedef Vector<GraphEdge> EdgeList;
  75     NodeList m_nodes;
  76     EdgeList m_edges;
  77     float m_zRange;
  78
  79     typedef HashMap<GraphEdge*, GraphEdge*> EdgeMap;
  80     EdgeMap m_activeEdges;
  81
  82     void createGraphNodes(LayerList::iterator first, LayerList::iterator last);
  83     void createGraphEdges();
  84     void removeEdgeFromList(GraphEdge*, Vector<GraphEdge*>&);
  85 };
  86
  87 }
  88 #endif