Initial QuadTree implementation

src/core/SkBBoxHierarchy.h

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBBoxHierarchy_DEFINED
 #define SkBBoxHierarchy_DEFINED
@@ skipping 46 matching lines @@
     virtual void flushDeferredInserts() = 0;
 
     /**
      * Populate 'results' with data pointers corresponding to bounding boxes that intersect 'query'
      */
     virtual void search(const SkIRect& query, SkTDArray<void*>* results) = 0;
 
     virtual void clear() = 0;
 
     /**
-     * Gets the number of insertions
+     * Gets the number of insertions actually made (does not include deferred insertions)
      */
     virtual int getCount() const = 0;
 
     /**
+     * Returns the depth of the currently allocated tree. The root node counts for 1 level,
+     * so it should be 1 or more if there's a root node. This information provides details
+     * about the underlying structure, which is useful mainly for testing purposes.
+     *
+     * Returns 0 if there are currently no nodes in the tree.
+     * Returns -1 if the structure isn't a tree.
+     */
+    virtual int getDepth() const = 0;
+
+    /**
      * Rewinds all the most recently inserted data elements until an element
      * is encountered for which client->shouldRewind(data) returns false. May
      * not rewind elements that were inserted prior to the last call to
      * flushDeferredInserts.
      */
     virtual void rewindInserts() = 0;
 
     void setClient(SkBBoxHierarchyClient* client) { fClient = client; }
 
 protected:
     SkBBoxHierarchyClient* fClient;
 
 private:
     typedef SkRefCnt INHERITED;
 };
 
 #endif