/* Copyright (c) 2007 Scott Lembcke *  * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: *  * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. *  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */// The spatial hash is Chipmunk's default (and currently only) spatial index type.// Based on a chained hash table.// Used internally to track objects added to the hashtypedef struct cpHandle{	// Pointer to the object	void *obj;	// Retain count	int retain;	// Query stamp. Used to make sure two objects	// aren't identified twice in the same query.	int stamp;} cpHandle;// Linked list element for in the chains.typedef struct cpSpaceHashBin{	cpHandle *handle;	struct cpSpaceHashBin *next;} cpSpaceHashBin;// BBox callback. Called whenever the hash needs a bounding box from an object.typedef cpBB (*cpSpaceHashBBFunc)(void *obj);typedef struct cpSpaceHash{	// Number of cells in the table.	int numcells;	// Dimentions of the cells.	cpFloat celldim;		// BBox callback.	cpSpaceHashBBFunc bbfunc;	// Hashset of all the handles.	cpHashSet *handleSet;		cpSpaceHashBin **table;	// List of recycled bins.	cpSpaceHashBin *bins;	// Incremented on each query. See cpHandle.stamp.	int stamp;} cpSpaceHash;//Basic allocation/destruction functions.cpSpaceHash *cpSpaceHashAlloc(void);cpSpaceHash *cpSpaceHashInit(cpSpaceHash *hash, cpFloat celldim, int cells, cpSpaceHashBBFunc bbfunc);cpSpaceHash *cpSpaceHashNew(cpFloat celldim, int cells, cpSpaceHashBBFunc bbfunc);void cpSpaceHashDestroy(cpSpaceHash *hash);void cpSpaceHashFree(cpSpaceHash *hash);// Resize the hashtable. (Does not rehash! You must call cpSpaceHashRehash() if needed.)void cpSpaceHashResize(cpSpaceHash *hash, cpFloat celldim, int numcells);// Add an object to the hash.void cpSpaceHashInsert(cpSpaceHash *hash, void *obj, unsigned int id, cpBB bb);// Remove an object from the hash.void cpSpaceHashRemove(cpSpaceHash *hash, void *obj, unsigned int id);// Iterator functiontypedef void (*cpSpaceHashIterator)(void *obj, void *data);// Iterate over the objects in the hash.void cpSpaceHashEach(cpSpaceHash *hash, cpSpaceHashIterator func, void *data);// Rehash the contents of the hash.void cpSpaceHashRehash(cpSpaceHash *hash);// Rehash only a specific object.void cpSpaceHashRehashObject(cpSpaceHash *hash, void *obj, unsigned int id);// Query callback.typedef int (*cpSpaceHashQueryFunc)(void *obj1, void *obj2, void *data);// Point query the hash. A reference to the query point is passed as obj1 to the query callback.void cpSpaceHashPointQuery(cpSpaceHash *hash, cpVect point, cpSpaceHashQueryFunc func, void *data);// Query the hash for a given BBox.void cpSpaceHashQuery(cpSpaceHash *hash, void *obj, cpBB bb, cpSpaceHashQueryFunc func, void *data);// Run a query for the object, then insert it. (Optimized case)void cpSpaceHashQueryInsert(cpSpaceHash *hash, void *obj, cpBB bb, cpSpaceHashQueryFunc func, void *data);// Rehashes while querying for each object. (Optimized case) void cpSpaceHashQueryRehash(cpSpaceHash *hash, cpSpaceHashQueryFunc func, void *data);