michael@0: 
michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkBBoxHierarchy_DEFINED
michael@0: #define SkBBoxHierarchy_DEFINED
michael@0: 
michael@0: #include "SkRect.h"
michael@0: #include "SkTDArray.h"
michael@0: #include "SkRefCnt.h"
michael@0: 
michael@0: /**
michael@0:  * Interface for a client class that implements utility methods needed
michael@0:  * by SkBBoxHierarchy that require intrinsic knowledge of the data
michael@0:  * object type that is stored in the bounding box hierarchy.
michael@0:  */
michael@0: class SkBBoxHierarchyClient {
michael@0: public:
michael@0:     virtual ~SkBBoxHierarchyClient() {}
michael@0: 
michael@0:     /**
michael@0:      * Implements a rewind stop condition used by rewindInserts
michael@0:      * Must returns true if 'data' points to an object that should be re-wound
michael@0:      * by rewinfInserts.
michael@0:      */
michael@0:     virtual bool shouldRewind(void* data) = 0;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Interface for a spatial data structure that associates user data pointers with axis-aligned
michael@0:  * bounding boxes, and allows efficient retrieval of intersections with query rectangles.
michael@0:  */
michael@0: class SkBBoxHierarchy : public SkRefCnt {
michael@0: public:
michael@0:     SK_DECLARE_INST_COUNT(SkBBoxHierarchy)
michael@0: 
michael@0:     SkBBoxHierarchy() : fClient(NULL) {}
michael@0: 
michael@0:     /**
michael@0:      * Insert a data pointer and corresponding bounding box
michael@0:      * @param data The data pointer, may be NULL
michael@0:      * @param bounds The bounding box, should not be empty
michael@0:      * @param defer Whether or not it is acceptable to delay insertion of this element (building up
michael@0:      *        an entire spatial data structure at once is often faster and produces better
michael@0:      *        structures than repeated inserts) until flushDeferredInserts is called or the first
michael@0:      *        search.
michael@0:      */
michael@0:     virtual void insert(void* data, const SkIRect& bounds, bool defer = false) = 0;
michael@0: 
michael@0:     /**
michael@0:      * If any insertions have been deferred, this forces them to be inserted
michael@0:      */
michael@0:     virtual void flushDeferredInserts() = 0;
michael@0: 
michael@0:     /**
michael@0:      * Populate 'results' with data pointers corresponding to bounding boxes that intersect 'query'
michael@0:      */
michael@0:     virtual void search(const SkIRect& query, SkTDArray<void*>* results) = 0;
michael@0: 
michael@0:     virtual void clear() = 0;
michael@0: 
michael@0:     /**
michael@0:      * Gets the number of insertions actually made (does not include deferred insertions)
michael@0:      */
michael@0:     virtual int getCount() const = 0;
michael@0: 
michael@0:     /**
michael@0:      * Returns the depth of the currently allocated tree. The root node counts for 1 level,
michael@0:      * so it should be 1 or more if there's a root node. This information provides details
michael@0:      * about the underlying structure, which is useful mainly for testing purposes.
michael@0:      *
michael@0:      * Returns 0 if there are currently no nodes in the tree.
michael@0:      * Returns -1 if the structure isn't a tree.
michael@0:      */
michael@0:     virtual int getDepth() const = 0;
michael@0: 
michael@0:     /**
michael@0:      * Rewinds all the most recently inserted data elements until an element
michael@0:      * is encountered for which client->shouldRewind(data) returns false. May
michael@0:      * not rewind elements that were inserted prior to the last call to
michael@0:      * flushDeferredInserts.
michael@0:      */
michael@0:     virtual void rewindInserts() = 0;
michael@0: 
michael@0:     void setClient(SkBBoxHierarchyClient* client) { fClient = client; }
michael@0: 
michael@0: protected:
michael@0:     SkBBoxHierarchyClient* fClient;
michael@0: 
michael@0: private:
michael@0:     typedef SkRefCnt INHERITED;
michael@0: };
michael@0: 
michael@0: #endif