axmol/external/chipmunk/src/cpSpaceHash.c

635 lines
15 KiB
C

/* 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.
*/
#include "chipmunk_private.h"
#include "prime.h"
typedef struct cpSpaceHashBin cpSpaceHashBin;
typedef struct cpHandle cpHandle;
struct cpSpaceHash {
cpSpatialIndex spatialIndex;
int numcells;
cpFloat celldim;
cpSpaceHashBin **table;
cpHashSet *handleSet;
cpSpaceHashBin *pooledBins;
cpArray *pooledHandles;
cpArray *allocatedBuffers;
cpTimestamp stamp;
};
//MARK: Handle Functions
struct cpHandle {
void *obj;
int retain;
cpTimestamp stamp;
};
static cpHandle*
cpHandleInit(cpHandle *hand, void *obj)
{
hand->obj = obj;
hand->retain = 0;
hand->stamp = 0;
return hand;
}
static inline void cpHandleRetain(cpHandle *hand){hand->retain++;}
static inline void
cpHandleRelease(cpHandle *hand, cpArray *pooledHandles)
{
hand->retain--;
if(hand->retain == 0) cpArrayPush(pooledHandles, hand);
}
static int handleSetEql(void *obj, cpHandle *hand){return (obj == hand->obj);}
static void *
handleSetTrans(void *obj, cpSpaceHash *hash)
{
if(hash->pooledHandles->num == 0){
// handle pool is exhausted, make more
int count = CP_BUFFER_BYTES/sizeof(cpHandle);
cpAssertHard(count, "Internal Error: Buffer size is too small.");
cpHandle *buffer = (cpHandle *)cpcalloc(1, CP_BUFFER_BYTES);
cpArrayPush(hash->allocatedBuffers, buffer);
for(int i=0; i<count; i++) cpArrayPush(hash->pooledHandles, buffer + i);
}
cpHandle *hand = cpHandleInit((cpHandle *)cpArrayPop(hash->pooledHandles), obj);
cpHandleRetain(hand);
return hand;
}
//MARK: Bin Functions
struct cpSpaceHashBin {
cpHandle *handle;
cpSpaceHashBin *next;
};
static inline void
recycleBin(cpSpaceHash *hash, cpSpaceHashBin *bin)
{
bin->next = hash->pooledBins;
hash->pooledBins = bin;
}
static inline void
clearTableCell(cpSpaceHash *hash, int idx)
{
cpSpaceHashBin *bin = hash->table[idx];
while(bin){
cpSpaceHashBin *next = bin->next;
cpHandleRelease(bin->handle, hash->pooledHandles);
recycleBin(hash, bin);
bin = next;
}
hash->table[idx] = NULL;
}
static void
clearTable(cpSpaceHash *hash)
{
for(int i=0; i<hash->numcells; i++) clearTableCell(hash, i);
}
// Get a recycled or new bin.
static inline cpSpaceHashBin *
getEmptyBin(cpSpaceHash *hash)
{
cpSpaceHashBin *bin = hash->pooledBins;
if(bin){
hash->pooledBins = bin->next;
return bin;
} else {
// Pool is exhausted, make more
int count = CP_BUFFER_BYTES/sizeof(cpSpaceHashBin);
cpAssertHard(count, "Internal Error: Buffer size is too small.");
cpSpaceHashBin *buffer = (cpSpaceHashBin *)cpcalloc(1, CP_BUFFER_BYTES);
cpArrayPush(hash->allocatedBuffers, buffer);
// push all but the first one, return the first instead
for(int i=1; i<count; i++) recycleBin(hash, buffer + i);
return buffer;
}
}
//MARK: Memory Management Functions
cpSpaceHash *
cpSpaceHashAlloc(void)
{
return (cpSpaceHash *)cpcalloc(1, sizeof(cpSpaceHash));
}
// Frees the old table, and allocate a new one.
static void
cpSpaceHashAllocTable(cpSpaceHash *hash, int numcells)
{
cpfree(hash->table);
hash->numcells = numcells;
hash->table = (cpSpaceHashBin **)cpcalloc(numcells, sizeof(cpSpaceHashBin *));
}
static inline cpSpatialIndexClass *Klass();
cpSpatialIndex *
cpSpaceHashInit(cpSpaceHash *hash, cpFloat celldim, int numcells, cpSpatialIndexBBFunc bbfunc, cpSpatialIndex *staticIndex)
{
cpSpatialIndexInit((cpSpatialIndex *)hash, Klass(), bbfunc, staticIndex);
cpSpaceHashAllocTable(hash, next_prime(numcells));
hash->celldim = celldim;
hash->handleSet = cpHashSetNew(0, (cpHashSetEqlFunc)handleSetEql);
hash->pooledHandles = cpArrayNew(0);
hash->pooledBins = NULL;
hash->allocatedBuffers = cpArrayNew(0);
hash->stamp = 1;
return (cpSpatialIndex *)hash;
}
cpSpatialIndex *
cpSpaceHashNew(cpFloat celldim, int cells, cpSpatialIndexBBFunc bbfunc, cpSpatialIndex *staticIndex)
{
return cpSpaceHashInit(cpSpaceHashAlloc(), celldim, cells, bbfunc, staticIndex);
}
static void
cpSpaceHashDestroy(cpSpaceHash *hash)
{
if(hash->table) clearTable(hash);
cpfree(hash->table);
cpHashSetFree(hash->handleSet);
cpArrayFreeEach(hash->allocatedBuffers, cpfree);
cpArrayFree(hash->allocatedBuffers);
cpArrayFree(hash->pooledHandles);
}
//MARK: Helper Functions
static inline cpBool
containsHandle(cpSpaceHashBin *bin, cpHandle *hand)
{
while(bin){
if(bin->handle == hand) return cpTrue;
bin = bin->next;
}
return cpFalse;
}
// The hash function itself.
static inline cpHashValue
hash_func(cpHashValue x, cpHashValue y, cpHashValue n)
{
return (x*1640531513ul ^ y*2654435789ul) % n;
}
// Much faster than (int)floor(f)
// Profiling showed floor() to be a sizable performance hog
static inline int
floor_int(cpFloat f)
{
int i = (int)f;
return (f < 0.0f && f != i ? i - 1 : i);
}
static inline void
hashHandle(cpSpaceHash *hash, cpHandle *hand, cpBB bb)
{
// Find the dimensions in cell coordinates.
cpFloat dim = hash->celldim;
int l = floor_int(bb.l/dim); // Fix by ShiftZ
int r = floor_int(bb.r/dim);
int b = floor_int(bb.b/dim);
int t = floor_int(bb.t/dim);
int n = hash->numcells;
for(int i=l; i<=r; i++){
for(int j=b; j<=t; j++){
cpHashValue idx = hash_func(i,j,n);
cpSpaceHashBin *bin = hash->table[idx];
// Don't add an object twice to the same cell.
if(containsHandle(bin, hand)) continue;
cpHandleRetain(hand);
// Insert a new bin for the handle in this cell.
cpSpaceHashBin *newBin = getEmptyBin(hash);
newBin->handle = hand;
newBin->next = bin;
hash->table[idx] = newBin;
}
}
}
//MARK: Basic Operations
static void
cpSpaceHashInsert(cpSpaceHash *hash, void *obj, cpHashValue hashid)
{
cpHandle *hand = (cpHandle *)cpHashSetInsert(hash->handleSet, hashid, obj, hash, (cpHashSetTransFunc)handleSetTrans);
hashHandle(hash, hand, hash->spatialIndex.bbfunc(obj));
}
static void
cpSpaceHashRehashObject(cpSpaceHash *hash, void *obj, cpHashValue hashid)
{
cpHandle *hand = (cpHandle *)cpHashSetRemove(hash->handleSet, hashid, obj);
if(hand){
hand->obj = NULL;
cpHandleRelease(hand, hash->pooledHandles);
cpSpaceHashInsert(hash, obj, hashid);
}
}
static void
rehash_helper(cpHandle *hand, cpSpaceHash *hash)
{
hashHandle(hash, hand, hash->spatialIndex.bbfunc(hand->obj));
}
static void
cpSpaceHashRehash(cpSpaceHash *hash)
{
clearTable(hash);
cpHashSetEach(hash->handleSet, (cpHashSetIteratorFunc)rehash_helper, hash);
}
static void
cpSpaceHashRemove(cpSpaceHash *hash, void *obj, cpHashValue hashid)
{
cpHandle *hand = (cpHandle *)cpHashSetRemove(hash->handleSet, hashid, obj);
if(hand){
hand->obj = NULL;
cpHandleRelease(hand, hash->pooledHandles);
}
}
typedef struct eachContext {
cpSpatialIndexIteratorFunc func;
void *data;
} eachContext;
static void eachHelper(cpHandle *hand, eachContext *context){context->func(hand->obj, context->data);}
static void
cpSpaceHashEach(cpSpaceHash *hash, cpSpatialIndexIteratorFunc func, void *data)
{
eachContext context = {func, data};
cpHashSetEach(hash->handleSet, (cpHashSetIteratorFunc)eachHelper, &context);
}
static void
remove_orphaned_handles(cpSpaceHash *hash, cpSpaceHashBin **bin_ptr)
{
cpSpaceHashBin *bin = *bin_ptr;
while(bin){
cpHandle *hand = bin->handle;
cpSpaceHashBin *next = bin->next;
if(!hand->obj){
// orphaned handle, unlink and recycle the bin
(*bin_ptr) = bin->next;
recycleBin(hash, bin);
cpHandleRelease(hand, hash->pooledHandles);
} else {
bin_ptr = &bin->next;
}
bin = next;
}
}
//MARK: Query Functions
static inline void
query_helper(cpSpaceHash *hash, cpSpaceHashBin **bin_ptr, void *obj, cpSpatialIndexQueryFunc func, void *data)
{
restart:
for(cpSpaceHashBin *bin = *bin_ptr; bin; bin = bin->next){
cpHandle *hand = bin->handle;
void *other = hand->obj;
if(hand->stamp == hash->stamp || obj == other){
continue;
} else if(other){
func(obj, other, data);
hand->stamp = hash->stamp;
} else {
// The object for this handle has been removed
// cleanup this cell and restart the query
remove_orphaned_handles(hash, bin_ptr);
goto restart; // GCC not smart enough/able to tail call an inlined function.
}
}
}
static void
cpSpaceHashQuery(cpSpaceHash *hash, void *obj, cpBB bb, cpSpatialIndexQueryFunc func, void *data)
{
// Get the dimensions in cell coordinates.
cpFloat dim = hash->celldim;
int l = floor_int(bb.l/dim); // Fix by ShiftZ
int r = floor_int(bb.r/dim);
int b = floor_int(bb.b/dim);
int t = floor_int(bb.t/dim);
int n = hash->numcells;
cpSpaceHashBin **table = hash->table;
// Iterate over the cells and query them.
for(int i=l; i<=r; i++){
for(int j=b; j<=t; j++){
query_helper(hash, &table[hash_func(i,j,n)], obj, func, data);
}
}
hash->stamp++;
}
// Similar to struct eachPair above.
typedef struct queryRehashContext {
cpSpaceHash *hash;
cpSpatialIndexQueryFunc func;
void *data;
} queryRehashContext;
// Hashset iterator func used with cpSpaceHashQueryRehash().
static void
queryRehash_helper(cpHandle *hand, queryRehashContext *context)
{
cpSpaceHash *hash = context->hash;
cpSpatialIndexQueryFunc func = context->func;
void *data = context->data;
cpFloat dim = hash->celldim;
int n = hash->numcells;
void *obj = hand->obj;
cpBB bb = hash->spatialIndex.bbfunc(obj);
int l = floor_int(bb.l/dim);
int r = floor_int(bb.r/dim);
int b = floor_int(bb.b/dim);
int t = floor_int(bb.t/dim);
cpSpaceHashBin **table = hash->table;
for(int i=l; i<=r; i++){
for(int j=b; j<=t; j++){
cpHashValue idx = hash_func(i,j,n);
cpSpaceHashBin *bin = table[idx];
if(containsHandle(bin, hand)) continue;
cpHandleRetain(hand); // this MUST be done first in case the object is removed in func()
query_helper(hash, &bin, obj, func, data);
cpSpaceHashBin *newBin = getEmptyBin(hash);
newBin->handle = hand;
newBin->next = bin;
table[idx] = newBin;
}
}
// Increment the stamp for each object hashed.
hash->stamp++;
}
static void
cpSpaceHashReindexQuery(cpSpaceHash *hash, cpSpatialIndexQueryFunc func, void *data)
{
clearTable(hash);
queryRehashContext context = {hash, func, data};
cpHashSetEach(hash->handleSet, (cpHashSetIteratorFunc)queryRehash_helper, &context);
cpSpatialIndexCollideStatic((cpSpatialIndex *)hash, hash->spatialIndex.staticIndex, func, data);
}
static inline cpFloat
segmentQuery_helper(cpSpaceHash *hash, cpSpaceHashBin **bin_ptr, void *obj, cpSpatialIndexSegmentQueryFunc func, void *data)
{
cpFloat t = 1.0f;
restart:
for(cpSpaceHashBin *bin = *bin_ptr; bin; bin = bin->next){
cpHandle *hand = bin->handle;
void *other = hand->obj;
// Skip over certain conditions
if(hand->stamp == hash->stamp){
continue;
} else if(other){
t = cpfmin(t, func(obj, other, data));
hand->stamp = hash->stamp;
} else {
// The object for this handle has been removed
// cleanup this cell and restart the query
remove_orphaned_handles(hash, bin_ptr);
goto restart; // GCC not smart enough/able to tail call an inlined function.
}
}
return t;
}
// modified from http://playtechs.blogspot.com/2007/03/raytracing-on-grid.html
static void
cpSpaceHashSegmentQuery(cpSpaceHash *hash, void *obj, cpVect a, cpVect b, cpFloat t_exit, cpSpatialIndexSegmentQueryFunc func, void *data)
{
a = cpvmult(a, 1.0f/hash->celldim);
b = cpvmult(b, 1.0f/hash->celldim);
int cell_x = floor_int(a.x), cell_y = floor_int(a.y);
cpFloat t = 0;
int x_inc, y_inc;
cpFloat temp_v, temp_h;
if (b.x > a.x){
x_inc = 1;
temp_h = (cpffloor(a.x + 1.0f) - a.x);
} else {
x_inc = -1;
temp_h = (a.x - cpffloor(a.x));
}
if (b.y > a.y){
y_inc = 1;
temp_v = (cpffloor(a.y + 1.0f) - a.y);
} else {
y_inc = -1;
temp_v = (a.y - cpffloor(a.y));
}
// Division by zero is *very* slow on ARM
cpFloat dx = cpfabs(b.x - a.x), dy = cpfabs(b.y - a.y);
cpFloat dt_dx = (dx ? 1.0f/dx : INFINITY), dt_dy = (dy ? 1.0f/dy : INFINITY);
// fix NANs in horizontal directions
cpFloat next_h = (temp_h ? temp_h*dt_dx : dt_dx);
cpFloat next_v = (temp_v ? temp_v*dt_dy : dt_dy);
int n = hash->numcells;
cpSpaceHashBin **table = hash->table;
while(t < t_exit){
cpHashValue idx = hash_func(cell_x, cell_y, n);
t_exit = cpfmin(t_exit, segmentQuery_helper(hash, &table[idx], obj, func, data));
if (next_v < next_h){
cell_y += y_inc;
t = next_v;
next_v += dt_dy;
} else {
cell_x += x_inc;
t = next_h;
next_h += dt_dx;
}
}
hash->stamp++;
}
//MARK: Misc
void
cpSpaceHashResize(cpSpaceHash *hash, cpFloat celldim, int numcells)
{
if(hash->spatialIndex.klass != Klass()){
cpAssertWarn(cpFalse, "Ignoring cpSpaceHashResize() call to non-cpSpaceHash spatial index.");
return;
}
clearTable(hash);
hash->celldim = celldim;
cpSpaceHashAllocTable(hash, next_prime(numcells));
}
static int
cpSpaceHashCount(cpSpaceHash *hash)
{
return cpHashSetCount(hash->handleSet);
}
static int
cpSpaceHashContains(cpSpaceHash *hash, void *obj, cpHashValue hashid)
{
return cpHashSetFind(hash->handleSet, hashid, obj) != NULL;
}
static cpSpatialIndexClass klass = {
(cpSpatialIndexDestroyImpl)cpSpaceHashDestroy,
(cpSpatialIndexCountImpl)cpSpaceHashCount,
(cpSpatialIndexEachImpl)cpSpaceHashEach,
(cpSpatialIndexContainsImpl)cpSpaceHashContains,
(cpSpatialIndexInsertImpl)cpSpaceHashInsert,
(cpSpatialIndexRemoveImpl)cpSpaceHashRemove,
(cpSpatialIndexReindexImpl)cpSpaceHashRehash,
(cpSpatialIndexReindexObjectImpl)cpSpaceHashRehashObject,
(cpSpatialIndexReindexQueryImpl)cpSpaceHashReindexQuery,
(cpSpatialIndexQueryImpl)cpSpaceHashQuery,
(cpSpatialIndexSegmentQueryImpl)cpSpaceHashSegmentQuery,
};
static inline cpSpatialIndexClass *Klass(){return &klass;}
//MARK: Debug Drawing
//#define CP_BBTREE_DEBUG_DRAW
#ifdef CP_BBTREE_DEBUG_DRAW
#include "OpenGL/gl.h"
#include "OpenGL/glu.h"
#include <GLUT/glut.h>
void
cpSpaceHashRenderDebug(cpSpatialIndex *index)
{
if(index->klass != &klass){
cpAssertWarn(cpFalse, "Ignoring cpSpaceHashRenderDebug() call to non-spatial hash spatial index.");
return;
}
cpSpaceHash *hash = (cpSpaceHash *)index;
cpBB bb = cpBBNew(-320, -240, 320, 240);
cpFloat dim = hash->celldim;
int n = hash->numcells;
int l = (int)floor(bb.l/dim);
int r = (int)floor(bb.r/dim);
int b = (int)floor(bb.b/dim);
int t = (int)floor(bb.t/dim);
for(int i=l; i<=r; i++){
for(int j=b; j<=t; j++){
int cell_count = 0;
int index = hash_func(i,j,n);
for(cpSpaceHashBin *bin = hash->table[index]; bin; bin = bin->next)
cell_count++;
GLfloat v = 1.0f - (GLfloat)cell_count/10.0f;
glColor3f(v,v,v);
glRectf(i*dim, j*dim, (i + 1)*dim, (j + 1)*dim);
}
}
}
#endif