derived form abstract operator class for edge collapse

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Nico Pietroni 2004-06-25 11:33:13 +00:00
parent e03613d6cd
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/****************************************************************************
* VCGLib o o *
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* (at your option) any later version. *
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* This program is distributed in the hope that it will be useful, *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt) *
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/****************************************************************************
History
****************************************************************************/
#ifndef __VCG_DECIMATION_COLLAPSE
#define __VCG_DECIMATION_COLLAPSE
#include<vcg\complex\tetramesh\decimation\decimation.h>
#include<vcg\complex\tetramesh\modify\edge_collapse.h>
namespace vcg{
namespace tetra{
/** \addtogroup tetramesh */
/*@{*/
/// This Class is specialization for the edge collapse
template<class TETRA_MESH_TYPE>
class Collapse: public vcg::tetra::LocalModification<TETRA_MESH_TYPE>
{
/// The tetrahedral mesh type
typedef typename TETRA_MESH_TYPE TetraMeshType;
/// The tetrahedron type
typedef typename TetraMeshType::TetraType TetraType;
/// The vertex type
typedef typename TetraType::VertexType VertexType;
/// The coordinate type
typedef typename TetraType::VertexType::CoordType CoordType;
/// The scalar type
typedef typename TetraMeshType::VertexType::ScalarType ScalarType;
/////the base type class
//typedef typename vcg::tetra::LocalModification LocalMod;
/// The HEdgePos type
typedef Pos<TetraType> PosType;
/// The HEdgePos Loop type
typedef PosLoop<TetraType> PosLType;
private:
///the new point that substitute the edge
Point3<ScalarType> _NewPoint;
///the pointer to edge collapser method
vcg::tetra::EdgeCollapse<TetraMeshType> *_EC;
///mark for up_dating
char _Imark;
///the pos of collapse
PosType pos;
///pointer to vertex that remain
VertexType *vrem;
public:
/// Default Constructor
Collapse()
{
_EC=NULL;
}
///Constructor with postype
Collapse(PosType p)
{
/* Imark=mark;*/
pos=p;
_EC=NULL;
}
~Collapse()
{
if (_EC!=NULL)
delete(_EC);
}
private:
///Return the aspect Ratio media of the tetrahedrons
///that share the adge to collapse
ScalarType _AspectRatioMedia(PosType p)
{
PosLType posl=PosLType(p.T(),p.F(),p.E(),p.V());
posl.Reset();
int num=0;
ScalarType ratio_media=0.f;
while(!posl.LoopEnd())
{
ratio_media+=posl.T()->AspectRatio();
posl.NextT();
num++;
}
ratio_media=ratio_media/num;
return (ratio_media);
}
///Modify pos and alfa to obtain the collapse that minimize the error
ScalarType _VolumePreservingError(PosType &pos,CoordType &new_point,int nsteps)
{
VertexType *ve0=(pos.T()->V(Tetra::VofE(pos.E(),0)));
VertexType *ve1=(pos.T()->V(Tetra::VofE(pos.E(),1)));
vrem =ve0;
bool ext_v0=ve0->IsB();
bool ext_v1=ve1->IsB();
ScalarType best_error=0.f;
if ((ext_v0)&&(!ext_v1))
new_point=ve0->P();
else
if ((!ext_v0)&&(ext_v1))
new_point=ve1->P();
else
if ((!ext_v0)&&(!ext_v1))
new_point=(ve0->P()+ve1->P())/2.f;
else
if ((ext_v0)&&(ext_v1))//both are external vertex
{
ScalarType step=1.f/(nsteps-1);
ScalarType Vol_Original=_EC->VolumeOriginal();
for (int i=0;i<nsteps;i++)
{
best_error=1000000.f;
ScalarType alfatemp=step*((double)i);
CoordType newPTemp=(ve0->P()*alfatemp) +(ve1->P()*(1.f-alfatemp));
//the error is the absolute value of difference of volumes
ScalarType error=fabs(Vol_Original-_EC->VolumeSimulateCollapse(pos,newPTemp));
if(error<best_error)
{
new_point=newPTemp;
best_error=error;
}
}
}
return (best_error);
}
public:
ScalarType ComputePriority()
{
return (_AspectRatioMedia(this->pos));
}
ScalarType ComputeError()
{
if (_EC==NULL)
{
_EC=new vcg::tetra::EdgeCollapse<TetraMeshType>();
_EC->FindSets(pos);
}
return (_VolumePreservingError(pos,_NewPoint,5));
}
void Execute()
{
if (_EC==NULL)
{
_EC=new vcg::tetra::EdgeCollapse<TetraMeshType>();
_EC->FindSets(pos);
}
_EC->DoCollapse(pos,_NewPoint);
}
bool PreserveTopology()
{
if (_EC==NULL)
{
_EC=new vcg::tetra::EdgeCollapse<TetraMeshType>();
_EC->FindSets(pos);
}
return(_EC->CheckPreconditions(pos,_NewPoint));
}
HeapRetType UpdateHeap()
{
HeapRetType h_ret;
assert(!vrem->IsD());
VTIterator<TetraType> VTi(vrem->VTb(),vrem->VTi());
while (!VTi.End())
{
for (int j=0;j<6;j++)
{
vcg::tetra::Pos<TetraType> p=Pos<TetraType>(VTi.Vt(),Tetra::FofE(j,0),j,Tetra::VofE(j,0));
h_ret.push_back(HeapRetElem(vcg::tetra::MTEdgeCollapse,p));
}
VTi++;
}
return (h_ret);
}
};
}//end namespace tetra
}//end namespace vcg
#endif