vcglib/vcg/complex/algorithms/create/mc_trivial_walker.h

362 lines
13 KiB
C++

/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004-2016 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
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* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt) *
* for more details. *
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****************************************************************************/
#ifndef __VCG_TRIVIAL_WALKER
#define __VCG_TRIVIAL_WALKER
#include<vcg/space/index/grid_util.h>
namespace vcg {
// Very simple volume class.
// just an example of the interface that the trivial walker expects
template <class VOX_TYPE>
class SimpleVolume : public BasicGrid<typename VOX_TYPE::ScalarType>
{
public:
typedef VOX_TYPE VoxelType;
typedef typename VoxelType::ScalarType ScalarType;
typedef typename BasicGrid<typename VOX_TYPE::ScalarType>::Box3x Box3x;
const Point3i &ISize() {return this->siz;} /// Dimensioni griglia come numero di celle per lato
ScalarType Val(const int &x,const int &y,const int &z) const {
return cV(x,y,z).V();
//else return numeric_limits<float>::quiet_NaN( );
}
ScalarType &Val(const int &x,const int &y,const int &z) {
return V(x,y,z).V();
//else return numeric_limits<float>::quiet_NaN( );
}
VOX_TYPE &V(const int &x,const int &y,const int &z) {
return Vol[x+y*this->siz[0]+z*this->siz[0]*this->siz[1]];
}
VOX_TYPE &V(const Point3i &pi) {
return Vol[ pi[0] + pi[1]*this->siz[0] + pi[2]*this->siz[0]*this->siz[1] ];
}
const VOX_TYPE &cV(const int &x,const int &y,const int &z) const {
return Vol[x+y*this->siz[0]+z*this->siz[0]*this->siz[1]];
}
bool ValidCell(const Point3i & /*p0*/, const Point3i & /*p1*/) const { return true;}
template < class VertexPointerType >
void GetXIntercept(const vcg::Point3i &p1, const vcg::Point3i &p2, VertexPointerType &v, const float thr)
{ GetIntercept<VertexPointerType,XAxis>(p1,p2,v,thr); }
template < class VertexPointerType >
void GetYIntercept(const vcg::Point3i &p1, const vcg::Point3i &p2, VertexPointerType &v, const float thr)
{ GetIntercept<VertexPointerType,YAxis>(p1,p2,v,thr); }
template < class VertexPointerType >
void GetZIntercept(const vcg::Point3i &p1, const vcg::Point3i &p2, VertexPointerType &v, const float thr)
{ GetIntercept<VertexPointerType,ZAxis>(p1,p2,v,thr); }
/// The following members/methods are just for this particular case.
/// The above one are the one required by the marching cube interface.
std::vector<VoxelType> Vol;
typedef enum { XAxis=0,YAxis=1,ZAxis=2} VolumeAxis;
template < class VertexPointerType, VolumeAxis AxisVal >
void GetIntercept(const vcg::Point3i &p1, const vcg::Point3i &p2, VertexPointerType &v, const float thr)
{
float f1 = V(p1).V()-thr;
float f2 = V(p2).V()-thr;
float u = (float) f1/(f1-f2);
if(AxisVal==XAxis) v->P().X() = (float) p1.X()*(1-u) + u*p2.X();
else v->P().X() = (float) p1.X();
if(AxisVal==YAxis) v->P().Y() = (float) p1.Y()*(1-u) + u*p2.Y();
else v->P().Y() = (float) p1.Y();
if(AxisVal==ZAxis) v->P().Z() = (float) p1.Z()*(1-u) + u*p2.Z();
else v->P().Z() = (float) p1.Z();
this->IPfToPf(v->P(),v->P());
if(VoxelType::HasNormal()) v->N().Import(V(p1).N()*(1-u) + V(p2).N()*u);
}
void Init(Point3i _sz, Box3x bb)
{
this->siz=_sz;
this->bbox = bb;
Vol.resize(this->siz[0]*this->siz[1]*this->siz[2]);
this->ComputeDimAndVoxel();
}
};
template <class _ScalarType=float>
class SimpleVoxel
{
private:
_ScalarType _v;
public:
typedef _ScalarType ScalarType;
ScalarType &V() {return _v;}
ScalarType V() const {return _v;}
static bool HasNormal() {return false;}
vcg::Point3<ScalarType> N() const {return Point3<ScalarType>(0,0,0);}
vcg::Point3<ScalarType> &N() { static Point3<ScalarType> _p(0,0,0); return _p;}
};
template <class _ScalarType=float>
class SimpleVoxelWithNormal
{
private:
_ScalarType _v;
vcg::Point3<_ScalarType> _n;
public:
typedef _ScalarType ScalarType;
ScalarType &V() {return _v;}
ScalarType V() const {return _v;}
vcg::Point3<ScalarType> &N() {return _n;}
vcg::Point3<ScalarType> N() const {return _n;}
static bool HasNormal() {return true;}
};
namespace tri {
// La classe Walker implementa la politica di visita del volume; conoscendo l'ordine di visita del volume
// Ë conveniente che il Walker stesso si faccia carico del caching dei dati utilizzati durante l'esecuzione
// degli algoritmi MarchingCubes ed ExtendedMarchingCubes, in particolare il calcolo del volume ai vertici
// delle celle e delle intersezioni della superficie con le celle. In questo esempio il volume da processare
// viene suddiviso in fette; in questo modo se il volume ha dimensione h*l*w (rispettivamente altezza,
// larghezza e profondit‡), lo spazio richiesto per il caching dei vertici gi‡ allocati passa da O(h*l*w)
// a O(h*l).
template <class MeshType, class VolumeType>
class TrivialWalker
{
private:
typedef int VertexIndex;
typedef typename MeshType::ScalarType ScalarType;
typedef typename MeshType::VertexPointer VertexPointer;
public:
// SetExtractionBox set the portion of the volume to be traversed
void SetExtractionBox(Box3i subbox)
{
_bbox = subbox;
_slice_dimension = _bbox.DimX()*_bbox.DimZ();
_x_cs = new VertexIndex[ _slice_dimension ];
_y_cs = new VertexIndex[ _slice_dimension ];
_z_cs = new VertexIndex[ _slice_dimension ];
_x_ns = new VertexIndex[ _slice_dimension ];
_z_ns = new VertexIndex[ _slice_dimension ];
}
TrivialWalker()
{
_bbox.SetNull();
_slice_dimension=0;
}
template<class EXTRACTOR_TYPE>
void BuildMesh(MeshType &mesh, VolumeType &volume, EXTRACTOR_TYPE &extractor, const float threshold, vcg::CallBackPos * cb=0)
{
if(_bbox.IsNull() || _slice_dimension==0)
SetExtractionBox(Box3i(Point3i(0,0,0),volume.ISize()));
_volume = &volume;
_mesh = &mesh;
_mesh->Clear();
_thr=threshold;
Begin();
extractor.Initialize();
for (int j=_bbox.min.Y(); j<(_bbox.max.Y()-1)-1; j+=1)
{
if(cb && ((j%10)==0) ) cb(j*_bbox.DimY()/100.0,"Marching volume");
for (int i=_bbox.min.X(); i<(_bbox.max.X()-1)-1; i+=1)
{
for (int k=_bbox.min.Z(); k<(_bbox.max.Z()-1)-1; k+=1)
{
Point3i p1(i,j,k);
Point3i p2(i+1,j+1,k+1);
if(volume.ValidCell(p1,p2))
extractor.ProcessCell(p1, p2);
}
}
NextYSlice();
}
extractor.Finalize();
_volume = NULL;
_mesh = NULL;
}
float V(int pi, int pj, int pk)
{
return _volume->Val(pi, pj, pk)-_thr;
}
bool Exist(const vcg::Point3i &p0, const vcg::Point3i &p1, VertexPointer &v)
{
int pos = p0.X()+p0.Z()*_bbox.DimX();
int vidx;
if (p0.X()!=p1.X()) // punti allineati lungo l'asse X
vidx = (p0.Y()==_current_slice) ? _x_cs[pos] : _x_ns[pos];
else if (p0.Y()!=p1.Y()) // punti allineati lungo l'asse Y
vidx = _y_cs[pos];
else if (p0.Z()!=p1.Z()) // punti allineati lungo l'asse Z
vidx = (p0.Y()==_current_slice)? _z_cs[pos] : _z_ns[pos];
else
assert(false);
v = (vidx!=-1)? &_mesh->vert[vidx] : NULL;
return v!=NULL;
}
void GetXIntercept(const vcg::Point3i &p1, const vcg::Point3i &p2, VertexPointer &v)
{
int i = p1.X() - _bbox.min.X();
int z = p1.Z() - _bbox.min.Z();
VertexIndex index = i+z*_bbox.DimX();
VertexIndex pos=-1;
if (p1.Y()==_current_slice)
{
if ((pos=_x_cs[index])==-1)
{
_x_cs[index] = (VertexIndex) _mesh->vert.size();
pos = _x_cs[index];
Allocator<MeshType>::AddVertices( *_mesh, 1 );
v = &_mesh->vert[pos];
_volume->GetXIntercept(p1, p2, v, _thr);
return;
}
}
if (p1.Y()==_current_slice+1)
{
if ((pos=_x_ns[index])==-1)
{
_x_ns[index] = (VertexIndex) _mesh->vert.size();
pos = _x_ns[index];
Allocator<MeshType>::AddVertices( *_mesh, 1 );
v = &_mesh->vert[pos];
_volume->GetXIntercept(p1, p2, v,_thr);
return;
}
}
assert(pos >=0 && size_t(pos)< _mesh->vert.size());
v = &_mesh->vert[pos];
}
void GetYIntercept(const vcg::Point3i &p1, const vcg::Point3i &p2, VertexPointer &v)
{
int i = p1.X() - _bbox.min.X();
int z = p1.Z() - _bbox.min.Z();
VertexIndex index = i+z*_bbox.DimX();
VertexIndex pos;
if ((pos=_y_cs[index])==-1)
{
_y_cs[index] = (VertexIndex) _mesh->vert.size();
pos = _y_cs[index];
Allocator<MeshType>::AddVertices( *_mesh, 1);
v = &_mesh->vert[ pos ];
_volume->GetYIntercept(p1, p2, v,_thr);
}
v = &_mesh->vert[pos];
}
void GetZIntercept(const vcg::Point3i &p1, const vcg::Point3i &p2, VertexPointer &v)
{
int i = p1.X() - _bbox.min.X();
int z = p1.Z() - _bbox.min.Z();
VertexIndex index = i+z*_bbox.DimX();
VertexIndex pos;
if (p1.Y()==_current_slice)
{
if ((pos=_z_cs[index])==-1)
{
_z_cs[index] = (VertexIndex) _mesh->vert.size();
pos = _z_cs[index];
Allocator<MeshType>::AddVertices( *_mesh, 1 );
v = &_mesh->vert[pos];
_volume->GetZIntercept(p1, p2, v,_thr);
return;
}
}
if (p1.Y()==_current_slice+1)
{
if ((pos=_z_ns[index])==-1)
{
_z_ns[index] = (VertexIndex) _mesh->vert.size();
pos = _z_ns[index];
Allocator<MeshType>::AddVertices( *_mesh, 1 );
v = &_mesh->vert[pos];
_volume->GetZIntercept(p1, p2, v,_thr);
return;
}
}
v = &_mesh->vert[pos];
}
protected:
Box3i _bbox;
int _slice_dimension;
int _current_slice;
VertexIndex *_x_cs; // indici dell'intersezioni della superficie lungo gli Xedge della fetta corrente
VertexIndex *_y_cs; // indici dell'intersezioni della superficie lungo gli Yedge della fetta corrente
VertexIndex *_z_cs; // indici dell'intersezioni della superficie lungo gli Zedge della fetta corrente
VertexIndex *_x_ns; // indici dell'intersezioni della superficie lungo gli Xedge della prossima fetta
VertexIndex *_z_ns; // indici dell'intersezioni della superficie lungo gli Zedge della prossima fetta
MeshType *_mesh;
VolumeType *_volume;
float _thr;
void NextYSlice()
{
memset(_x_cs, -1, _slice_dimension*sizeof(VertexIndex));
memset(_y_cs, -1, _slice_dimension*sizeof(VertexIndex));
memset(_z_cs, -1, _slice_dimension*sizeof(VertexIndex));
std::swap(_x_cs, _x_ns);
std::swap(_z_cs, _z_ns);
_current_slice += 1;
}
void Begin()
{
_current_slice = _bbox.min.Y();
memset(_x_cs, -1, _slice_dimension*sizeof(VertexIndex));
memset(_y_cs, -1, _slice_dimension*sizeof(VertexIndex));
memset(_z_cs, -1, _slice_dimension*sizeof(VertexIndex));
memset(_x_ns, -1, _slice_dimension*sizeof(VertexIndex));
memset(_z_ns, -1, _slice_dimension*sizeof(VertexIndex));
}
};
} // end namespace tri
} // end namespace vcg
#endif // __VCGTEST_WALKER