1 files changed, 28 insertions, 4 deletions
diff --git a/src/declarative/scenegraph/coreapi/qsgdefaultrenderer_p.h b/src/declarative/scenegraph/coreapi/qsgdefaultrenderer_p.h
index ca1f5592cf..f2adb00391 100644
--- a/src/declarative/scenegraph/coreapi/qsgdefaultrenderer_p.h
+++ b/src/declarative/scenegraph/coreapi/qsgdefaultrenderer_p.h
@@ -52,11 +52,36 @@ QT_BEGIN_NAMESPACE
 
 QT_MODULE(Declarative)
 
-class QMLRenderer : public QSGRenderer
+class IndexGeometryNodePair : public QPair<int, QSGGeometryNode *>
+{
+public:
+    IndexGeometryNodePair(int i, QSGGeometryNode *n);
+    bool operator < (const IndexGeometryNodePair &other) const;
+};
+
+
+// Minimum heap.
+class IndexGeometryNodePairHeap
+{
+public:
+    IndexGeometryNodePairHeap();
+    void insert(const IndexGeometryNodePair &x);
+    const IndexGeometryNodePair &top() const { return v.first(); }
+    IndexGeometryNodePair pop();
+    bool isEmpty() const { return v.isEmpty(); }
+private:
+    static int parent(int i) { return (i - 1) >> 1; }
+    static int left(int i) { return (i << 1) | 1; }
+    static int right(int i) { return (i + 1) << 1; }
+    QDataBuffer<IndexGeometryNodePair> v;
+};
+
+
+class QSGDefaultRenderer : public QSGRenderer
 {
     Q_OBJECT
 public:
-    QMLRenderer(QSGContext *context);
+    QSGDefaultRenderer(QSGContext *context);
 
     void render();
 
@@ -77,14 +102,13 @@ private:
     QDataBuffer<QSGGeometryNode *> m_opaqueNodes;
     QDataBuffer<QSGGeometryNode *> m_transparentNodes;
     QDataBuffer<QSGGeometryNode *> m_tempNodes;
+    IndexGeometryNodePairHeap m_heap;
 
     bool m_rebuild_lists;
     bool m_needs_sorting;
     bool m_sort_front_to_back;
     int m_currentRenderOrder;
 
-
-
 #ifdef QML_RUNTIME_TESTING
     bool m_render_opaque_nodes;
     bool m_render_alpha_nodes;