vcglib/vcg/space/index/spatial_hashing.h

359 lines
7.2 KiB
C++

#ifndef SPATIAL_HASHING
#define SPATIAL_HASHING
//#define P0 73856093
//#define P1 19349663
//#define P2 83492791
#define P0 73
#define P1 19
#define P2 83
#include <map>
#include <hash_map>
#include <vector>
template <class SimplexType>
class SpatialHashTable{
public:
typedef typename SimplexType* SimplexPointer;
typedef typename SimplexType::CoordType Point3x;
typedef typename Point3x::ScalarType ScalarType;
//iterator to the map element into the cell
typedef typename std::map<SimplexType*,int>::iterator IteMap;
//element of a cell
typedef typename std::pair<SimplexType*,int> MapCellElem;
//element stored in the hash table
struct Helement
{
std::map<SimplexType*,int> Elem;
//int flag;
public:
Helement()
{
// flag=0;
}
Helement(SimplexType* sim,int _tempMark)
{
Elem.insert(MapCellElem(sim,_tempMark));
// flag=0;
}
///return true if the element is in the cell
bool IsIn(SimplexType* sim)
{
int n=Elem.count(sim);
return (n==1);
}
int Size()
{
return (Elem.size());
}
///update or insert an element into a cell
void Update(SimplexType* sim,int _tempMark)
{
std::pair<IteMap, bool> res=Elem.insert(MapCellElem(sim,_tempMark));
//the element was already in the map structure so update the temporary mark
if (res.second==false)
{
//update the temporary mark
IteMap ite=res.first;
(*ite).second=_tempMark;
}
}
//return an array of all simplexes of the map that have a right timastamp or are not deleted
std::vector<SimplexType*> Simplexes(int _tempMark)
{
std::vector<SimplexType*> result;
result.clear();
for (IteMap ite=Elem.begin();ite!=Elem.end();ite++)
{
SimplexType* sim=(*ite).first;
int t=(*ite).second;
if ((!sim->IsD())&&(t>=_tempMark))
result.push_back(sim);
}
return (result);
}
};
//enum {
// // First user bit
// USER0 = 0x0001 // First user bit
// };
//static int &LastBitFlag()
// {
// static int b =USER0;
// return b;
// }
///// allocate a bit among the flags that can be used by user.
//static inline int NewBitFlag()
// {
// LastBitFlag()=LastBitFlag()<<1;
// return LastBitFlag();
// }
//// de-allocate a bit among the flags that can be used by user.
//static inline bool DeleteBitFlag(int bitval)
// {
// if(LastBitFlag()==bitval) {
// LastBitFlag()= LastBitFlag()>>1;
// return true;
// }
// assert(0);
// return false;
// }
//hash table definition
typedef typename std::hash_map<int,Helement> Htable;
//record of the hash table
typedef typename std::pair<int,Helement> HRecord;
//iterator to the hash table
typedef typename Htable::iterator IteHtable;
//SpatialHashTable(ContSimplex & r_):_simplex(r_){};
SpatialHashTable(){};
~SpatialHashTable(){};
//ContSimplex & _simplex;
int TempMark;
Htable hash_table;
int num;
float l;
Point3x min;
Point3x max;
void Init(Point3x _min,Point3x _max,ScalarType _l)
{
min=_min;
max=_max;
l=_l;
Point3x d=max-min;
num=floor(d.V(0)*d.V(1)*d.V(2)/l);
TempMark=0;
}
void InsertInCell(SimplexType* s,Point3i cell)
{
int h=Hash(cell);
//insert a cell if there isn't
if (hash_table.count(h)==0)
hash_table.insert(HRecord(h,Helement(s,TempMark)));
//otherwise insert the element or update the temporary mark
else
{
IteHtable HI=hash_table.find(h);
// (*HI).second.flag|=_flag;
(*HI).second.Update(s,TempMark);
}
}
std::vector<Point3i> addBox(SimplexType* s,Point3x _min,Point3x _max)
{
std::vector<Point3i> box=BoxCells(_min,_max);
for (std::vector<Point3i>::iterator bi=box.begin();bi<box.end();bi++)
InsertInCell(s,*bi);
return box;
}
std::vector<Point3i> BoxCells(Point3x _min,Point3x _max)
{
std::vector<Point3i> ret;
ret.clear();
Point3i MinI=Cell(_min);
Point3i MaxI=Cell(_max);
int dimx=abs(MaxI.V(0)-MinI.V(0));
int dimy=abs(MaxI.V(1)-MinI.V(1));
int dimz=abs(MaxI.V(2)-MinI.V(2));
for (int x=0;x<=dimx;x++)
for (int y=0;y<=dimy;y++)
for (int z=0;z<=dimz;z++)
{
Point3i cell=Point3i(MinI.V(0)+x,MinI.V(1)+y,MinI.V(2)+z);
ret.push_back(cell);
}
return ret;
}
std::vector<Point3i> Cells(SimplexType *s)
{
Point3x min=Point3x((*s).V(0)->P());
Point3x max=min;
//find min max coordinate of bounding box
for (int i=1;i<3;i++)
{
if (min.V(0)>(*s).V(i)->P().V(0))
min.V(0)=(*s).V(i)->P().V(0);
if (min.V(1)>(*s).V(i)->P().V(1))
min.V(1)=(*s).V(i)->P().V(1);
if (min.V(2)>(*s).V(i)->P().V(2))
min.V(2)=(*s).V(i)->P().V(2);
if (max.V(0)<(*s).V(i)->P().V(0))
max.V(0)=(*s).V(i)->P().V(0);
if (max.V(1)<(*s).V(i)->P().V(1))
max.V(1)=(*s).V(i)->P().V(1);
if (max.V(2)>(*s).V(i)->P().V(2))
max.V(2)=(*s).V(i)->P().V(2);
}
return BoxCells(s,min,max);
}
std::vector<Point3i> addSimplex(SimplexType *s)
{
Point3x min=Point3x((*s).V(0)->P());
Point3x max=min;
//find min max coordinate of bounding box
for (int i=1;i<3;i++)
{
if (min.V(0)>(*s).V(i)->P().V(0))
min.V(0)=(*s).V(i)->P().V(0);
if (min.V(1)>(*s).V(i)->P().V(1))
min.V(1)=(*s).V(i)->P().V(1);
if (min.V(2)>(*s).V(i)->P().V(2))
min.V(2)=(*s).V(i)->P().V(2);
if (max.V(0)<(*s).V(i)->P().V(0))
max.V(0)=(*s).V(i)->P().V(0);
if (max.V(1)<(*s).V(i)->P().V(1))
max.V(1)=(*s).V(i)->P().V(1);
if (max.V(2)>(*s).V(i)->P().V(2))
max.V(2)=(*s).V(i)->P().V(2);
}
///now set the cell touched by the bounding box of the triangle
return (addBox(s,min,max));
}
inline Point3i MinCell()
{
return Cell(min);
}
inline Point3i MaxCell()
{
return Cell(max);
}
inline int numElemCell(Point3i _c)
{
int h=Hash(_c);
if (hash_table.count(h)==0)
return 0;
else
{
IteHtable Ih=hash_table.find(h);
return ((*Ih).second.Size());
}
}
///refresh all the alement in the container
/*void RefreshElements()
{
TempMark++;
for (SimplexIterator si=_simplex.begin();si<_simplex.end();++si)
{
if (!(*si).IsD())
addSimplex(&*si);
}
}*/
///erase all element of the hash table where the timestamp is old
//void Clean()
//{
// for (IteHtable Ih=hash_table.begin();Ih!=hash_table.end();Ih++)
// //if after clean there are no element erase the cell
// if ((*Ih).second.Clean(TempMark))
// hash_table.erase(Ih);
//}
/*void Clean()
{
hash_table.clear();
RefreshElements();
}*/
void Clear()
{
hash_table.clear();
}
/*int FlagCell(Point3i p)
{
int h=Hash(p);
if (hash_table.count(h)==0)
return 0;
else
{
IteHtable Ih=hash_table.find(h);
return ((*Ih).second.Flag());
}
}*/
std::vector<SimplexPointer> getAt(Point3x _p)
{
std::vector<SimplexPointer> result;
Point3i c=Cell(p);
return (getAtCell(c));
}
std::vector<SimplexPointer> getAtCell(Point3i _c)
{
std::vector<SimplexPointer> result;
int h=Hash(_c);
if (numElemCell(_c)==0)
{
return result;
}
else
{
IteHtable res=hash_table.find(h);
return ((*res).second.Simplexes(TempMark));
}
}
private:
Point3i Cell(Point3x p)
{
int x=floor(p.V(0)/l);
int y=floor(p.V(1)/l);
int z=floor(p.V(2)/l);
return Point3i(x,y,z);
}
int Hash(Point3i p)
{
return ((p.V(0)*P0 ^ p.V(1)*P1 ^ p.V(2)*P2)%num);
}
};
#endif