vcglib/vcg/simplex/face/topology.h

862 lines
23 KiB
C++

/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
* *
* 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. *
* *
****************************************************************************/
#ifndef _VCG_FACE_TOPOLOGY
#define _VCG_FACE_TOPOLOGY
#include <vcg/simplex/face/pos.h>
#include <vector>
#include <algorithm>
namespace vcg {
namespace face {
/** \addtogroup face */
/*@{*/
/** Return a boolean that indicate if the face is complex.
@param j Index of the edge
@return true se la faccia e' manifold, false altrimenti
*/
template <class FaceType>
inline bool IsManifold( FaceType const & f, const int j )
{
assert(f.cFFp(j) != 0); // never try to use this on uncomputed topology
if(FaceType::HasFFAdjacency())
return ( f.cFFp(j) == &f || &f == f.cFFp(j)->cFFp(f.cFFi(j)) );
else
return true;
}
/** Return a boolean that indicate if the j-th edge of the face is a border.
@param j Index of the edge
@return true if j is an edge of border, false otherwise
*/
template <class FaceType>
inline bool IsBorder(FaceType const & f, const int j )
{
if(FaceType::HasFFAdjacency())
return f.cFFp(j)==&f;
//return f.IsBorder(j);
assert(0);
return true;
}
/// Count border edges of the face
template <class FaceType>
inline int BorderCount(FaceType const & f)
{
if(FaceType::HasFFAdjacency())
{
int t = 0;
if( IsBorder(f,0) ) ++t;
if( IsBorder(f,1) ) ++t;
if( IsBorder(f,2) ) ++t;
return t;
}
else return 3;
}
/// Counts the number of incident faces in a complex edge
template <class FaceType>
inline int ComplexSize(FaceType & f, const int e)
{
if(FaceType::HasFFAdjacency())
{
if(face::IsBorder<FaceType>(f,e)) return 1;
if(face::IsManifold<FaceType>(f,e)) return 2;
// Non manifold case
Pos< FaceType > fpos(&f,e);
int cnt=0;
do
{
fpos.NextF();
assert(!fpos.IsBorder());
assert(!fpos.IsManifold());
++cnt;
}
while(fpos.f!=&f);
assert (cnt>2);
return cnt;
}
assert(0);
return 2;
}
/** This function check the FF topology correctness for an edge of a face.
It's possible to use it also in non-two manifold situation.
The function cannot be applicated if the adjacencies among faces aren't defined.
@param f the face to be checked
@param e Index of the edge to be checked
*/
template <class FaceType>
bool FFCorrectness(FaceType & f, const int e)
{
if(f.FFp(e)==0) return false; // Not computed or inconsistent topology
if(f.FFp(e)==&f) // Border
{
if(f.FFi(e)==e) return true;
else return false;
}
if(f.FFp(e)->FFp(f.FFi(e))==&f) // plain two manifold
{
if(f.FFp(e)->FFi(f.FFi(e))==e) return true;
else return false;
}
// Non Manifold Case
// all the faces must be connected in a loop.
Pos< FaceType > curFace(&f,e); // Build the half edge
int cnt=0;
do
{
if(curFace.IsManifold()) return false;
if(curFace.IsBorder()) return false;
curFace.NextF();
cnt++;
assert(cnt<100);
}
while ( curFace.f != &f);
return true;
}
/** This function detach the face from the adjacent face via the edge e.
It's possible to use this function it ONLY in non-two manifold situation.
The function cannot be applicated if the adjacencies among faces aren't defined.
@param f the face to be detached
@param e Index of the edge to be detached
*/
template <class FaceType>
void FFDetachManifold(FaceType & f, const int e)
{
assert(FFCorrectness<FaceType>(f,e));
assert(!IsBorder<FaceType>(f,e)); // Never try to detach a border edge!
FaceType *ffp = f.FFp(e);
//int ffi=f.FFp(e);
int ffi=f.FFi(e);
f.FFp(e)=&f;
f.FFi(e)=e;
ffp->FFp(ffi)=ffp;
ffp->FFi(ffi)=ffi;
f.SetB(e);
f.ClearF(e);
ffp->SetB(ffi);
ffp->ClearF(ffi);
assert(FFCorrectness<FaceType>(f,e));
assert(FFCorrectness<FaceType>(*ffp,ffi));
}
/** This function detach the face from the adjacent face via the edge e.
It's possible to use it also in non-two manifold situation.
The function cannot be applicated if the adjacencies among faces aren't defined.
@param f the face to be detached
@param e Index of the edge to be detached
*/
template <class FaceType>
void FFDetach(FaceType & f, const int e)
{
assert(FFCorrectness<FaceType>(f,e));
assert(!IsBorder<FaceType>(f,e)); // Never try to detach a border edge!
int complexity;
assert(complexity=ComplexSize(f,e));
Pos< FaceType > FirstFace(&f,e); // Build the half edge
Pos< FaceType > LastFace(&f,e); // Build the half edge
FirstFace.NextF();
LastFace.NextF();
int cnt=0;
// then in case of non manifold face continue to advance LastFace
// until I find it become the one that
// preceed the face I want to erase
while ( LastFace.f->FFp(LastFace.z) != &f)
{
assert(ComplexSize(*LastFace.f,LastFace.z)==complexity);
assert(!LastFace.IsManifold()); // We enter in this loop only if we are on a non manifold edge
assert(!LastFace.IsBorder());
LastFace.NextF();
cnt++;
assert(cnt<100);
}
assert(LastFace.f->FFp(LastFace.z)==&f);
assert(f.FFp(e)== FirstFace.f);
// Now we link the last one to the first one, skipping the face to be detached;
LastFace.f->FFp(LastFace.z) = FirstFace.f;
LastFace.f->FFi(LastFace.z) = FirstFace.z;
assert(ComplexSize(*LastFace.f,LastFace.z)==complexity-1);
// At the end selfconnect the chosen edge to make a border.
f.FFp(e) = &f;
f.FFi(e) = e;
assert(ComplexSize(f,e)==1);
assert(FFCorrectness<FaceType>(*LastFace.f,LastFace.z));
assert(FFCorrectness<FaceType>(f,e));
}
/** This function attach the face (via the edge z1) to another face (via the edge z2). It's possible to use it also in non-two manifold situation.
The function cannot be applicated if the adjacencies among faces aren't define.
@param z1 Index of the edge
@param f2 Pointer to the face
@param z2 The edge of the face f2
*/
template <class FaceType>
void FFAttach(FaceType * &f, int z1, FaceType *&f2, int z2)
{
//typedef FEdgePosB< FACE_TYPE > ETYPE;
Pos< FaceType > EPB(f2,z2);
Pos< FaceType > TEPB;
TEPB = EPB;
EPB.NextF();
while( EPB.f != f2) //Alla fine del ciclo TEPB contiene la faccia che precede f2
{
TEPB = EPB;
EPB.NextF();
}
//Salvo i dati di f1 prima di sovrascrivere
FaceType *f1prec = f->FFp(z1);
int z1prec = f->FFi(z1);
//Aggiorno f1
f->FFp(z1) = TEPB.f->FFp(TEPB.z);
f->FFi(z1) = TEPB.f->FFi(TEPB.z);
//Aggiorno la faccia che precede f2
TEPB.f->FFp(TEPB.z) = f1prec;
TEPB.f->FFi(TEPB.z) = z1prec;
}
/** This function attach the face (via the edge z1) to another face (via the edge z2).
It is not possible to use it also in non-two manifold situation.
The function cannot be applicated if the adjacencies among faces aren't define.
@param z1 Index of the edge
@param f2 Pointer to the face
@param z2 The edge of the face f2
*/
template <class FaceType>
void FFAttachManifold(FaceType * &f1, int z1, FaceType *&f2, int z2)
{
assert(IsBorder<FaceType>(*f1,z1));
assert(IsBorder<FaceType>(*f2,z2));
assert(f1->V0(z1) == f2->V0(z2) || f1->V0(z1) == f2->V1(z2));
assert(f1->V1(z1) == f2->V0(z2) || f1->V1(z1) == f2->V1(z2));
f1->FFp(z1) = f2;
f1->FFi(z1) = z2;
f2->FFp(z2) = f1;
f2->FFi(z2) = z1;
}
// This one should be called only on uniitialized faces.
template <class FaceType>
void FFSetBorder(FaceType * &f1, int z1)
{
assert(f1->FFp(z1)==0 || IsBorder(*f1,z1));
f1->FFp(z1)=f1;
f1->FFi(z1)=z1;
}
template <class FaceType>
void AssertAdj(FaceType & f)
{
assert(f.FFp(0)->FFp(f.FFi(0))==&f);
assert(f.FFp(1)->FFp(f.FFi(1))==&f);
assert(f.FFp(2)->FFp(f.FFi(2))==&f);
assert(f.FFp(0)->FFi(f.FFi(0))==0);
assert(f.FFp(1)->FFi(f.FFi(1))==1);
assert(f.FFp(2)->FFi(f.FFi(2))==2);
}
/**
* Check if the given face is oriented as the one adjacent to the specified edge.
* @param f Face to check the orientation
* @param z Index of the edge
*/
template <class FaceType>
bool CheckOrientation(FaceType &f, int z)
{
if (IsBorder(f, z))
return true;
else
{
FaceType *g = f.FFp(z);
int gi = f.FFi(z);
if (f.V0(z) == g->V1(gi))
return true;
else
return false;
}
}
/**
* This function change the orientation of the face by inverting the index of two vertex.
* @param z Index of the edge
*/
template <class FaceType>
void SwapEdge(FaceType &f, const int z) { SwapEdge<FaceType,true>(f,z); }
template <class FaceType, bool UpdateTopology>
void SwapEdge(FaceType &f, const int z)
{
// swap V0(z) with V1(z)
std::swap(f.V0(z), f.V1(z));
if(f.HasFFAdjacency() && UpdateTopology)
{
// store information to preserve topology
int z1 = (z+1)%3;
int z2 = (z+2)%3;
FaceType *g1p = f.FFp(z1);
FaceType *g2p = f.FFp(z2);
int g1i = f.FFi(z1);
int g2i = f.FFi(z2);
// g0 face topology is not affected by the swap
if (g1p != &f)
{
g1p->FFi(g1i) = z2;
f.FFi(z2) = g1i;
}
else
{
f.FFi(z2) = z2;
}
if (g2p != &f)
{
g2p->FFi(g2i) = z1;
f.FFi(z1) = g2i;
}
else
{
f.FFi(z1) = z1;
}
// finalize swap
f.FFp(z1) = g2p;
f.FFp(z2) = g1p;
}
}
/*!
* Perform a Geometric Check about the normals of a edge flip.
* return trues if after the flip the normals does not change more than the given threshold angle;
* it assumes that the flip is topologically correct.
*
* \param f the face
* \param z the edge index
* \param angleRad the threshold angle
*
* oldD1 ___________ newD1
* |\ |
* | \ |
* | \ |
* | f z\ |
* | \ |
* |__________\|
* newD0 oldD0
*/
template <class FaceType>
static bool CheckFlipEdgeNormal(FaceType &f, const int z, const float angleRad)
{
typedef typename FaceType::VertexType VertexType;
typedef typename VertexType::CoordType CoordType;
typedef typename VertexType::ScalarType ScalarType;
VertexType *OldDiag0 = f.V0(z);
VertexType *OldDiag1 = f.V1(z);
VertexType *NewDiag0 = f.V2(z);
VertexType *NewDiag1 = f.FFp(z)->V2(f.FFi(z));
assert((NewDiag1 != NewDiag0) && (NewDiag1 != OldDiag0) && (NewDiag1 != OldDiag1));
CoordType oldN0 = NormalizedNormal( NewDiag0->cP(),OldDiag0->cP(),OldDiag1->cP());
CoordType oldN1 = NormalizedNormal( NewDiag1->cP(),OldDiag1->cP(),OldDiag0->cP());
CoordType newN0 = NormalizedNormal( OldDiag0->cP(),NewDiag1->cP(),NewDiag0->cP());
CoordType newN1 = NormalizedNormal( OldDiag1->cP(),NewDiag0->cP(),NewDiag1->cP());
if(AngleN(oldN0,newN0) > angleRad) return false;
if(AngleN(oldN0,newN1) > angleRad) return false;
if(AngleN(oldN1,newN0) > angleRad) return false;
if(AngleN(oldN1,newN1) > angleRad) return false;
return true;
}
/*!
* Perform a Topological check to see if the z-th edge of the face f can be flipped.
* No Geometric test are done. (see CheckFlipEdgeNormal)
* \param f pointer to the face
* \param z the edge index
*/
template <class FaceType>
static bool CheckFlipEdge(FaceType &f, int z)
{
typedef typename FaceType::VertexType VertexType;
typedef typename vcg::face::Pos< FaceType > PosType;
if (z<0 || z>2) return false;
// boundary edges cannot be flipped
if (face::IsBorder(f, z)) return false;
FaceType *g = f.FFp(z);
int w = f.FFi(z);
// check if the vertices of the edge are the same
// e.g. the mesh has to be well oriented
if (g->V(w)!=f.V1(z) || g->V1(w)!=f.V(z) )
return false;
// check if the flipped edge is already present in the mesh
// f_v2 and g_v2 are the vertices of the new edge
VertexType *f_v2 = f.V2(z);
VertexType *g_v2 = g->V2(w);
// just a sanity check. If this happens the mesh is not manifold.
if (f_v2 == g_v2) return false;
// Now walk around f_v2, one of the two vertexes of the new edge
// and check that it does not already exists.
PosType pos(&f, (z+2)%3, f_v2);
PosType startPos=pos;
do
{
pos.NextE();
if (g_v2 == pos.VFlip())
return false;
}
while (pos != startPos);
return true;
}
/*!
* Flip the z-th edge of the face f.
* Check for topological correctness first using <CODE>CheckFlipFace()</CODE>.
* \param f pointer to the face
* \param z the edge index
*
* Note: For <em>edge flip</em> we intend the swap of the diagonal of the rectangle
* formed by the face \a f and the face adjacent to the specified edge.
*/
template <class FaceType>
static void FlipEdge(FaceType &f, const int z)
{
assert(z>=0);
assert(z<3);
assert( !IsBorder(f,z) );
assert( face::IsManifold<FaceType>(f, z));
FaceType *g = f.FFp(z);
int w = f.FFi(z);
assert( g->V(w) == f.V1(z) );
assert( g->V1(w)== f.V(z) );
assert( g->V2(w)!= f.V(z) );
assert( g->V2(w)!= f.V1(z) );
assert( g->V2(w)!= f.V2(z) );
f.V1(z) = g->V2(w);
g->V1(w) = f.V2(z);
f.FFp(z) = g->FFp((w+1)%3);
f.FFi(z) = g->FFi((w+1)%3);
g->FFp(w) = f.FFp((z+1)%3);
g->FFi(w) = f.FFi((z+1)%3);
f.FFp((z+1)%3) = g;
f.FFi((z+1)%3) = (w+1)%3;
g->FFp((w+1)%3) = &f;
g->FFi((w+1)%3) = (z+1)%3;
if(f.FFp(z)==g)
{
f.FFp(z) = &f;
f.FFi(z) = z;
}
else
{
f.FFp(z)->FFp( f.FFi(z) ) = &f;
f.FFp(z)->FFi( f.FFi(z) ) = z;
}
if(g->FFp(w)==&f)
{
g->FFp(w)=g;
g->FFi(w)=w;
}
else
{
g->FFp(w)->FFp( g->FFi(w) ) = g;
g->FFp(w)->FFi( g->FFi(w) ) = w;
}
}
template <class FaceType>
void VFDetach(FaceType & f)
{
VFDetach(f,0);
VFDetach(f,1);
VFDetach(f,2);
}
// Stacca la faccia corrente dalla catena di facce incidenti sul vertice z,
// NOTA funziona SOLO per la topologia VF!!!
// usata nelle classi di collapse
template <class FaceType>
void VFDetach(FaceType & f, int z)
{
if(f.V(z)->VFp()==&f ) //if it is the first face detach from the begin
{
int fz = f.V(z)->VFi();
f.V(z)->VFp() = f.VFp(fz);
f.V(z)->VFi() = f.VFi(fz);
}
else // scan the list of faces in order to finde the current face f to be detached
{
VFIterator<FaceType> x(f.V(z)->VFp(),f.V(z)->VFi());
VFIterator<FaceType> y;
for(;;)
{
y = x;
++x;
assert(x.f!=0);
if(x.f==&f) // found!
{
y.f->VFp(y.z) = f.VFp(z);
y.f->VFi(y.z) = f.VFi(z);
break;
}
}
}
}
/// Append a face in VF list of vertex f->V(z)
template <class FaceType>
void VFAppend(FaceType* & f, int z)
{
typename FaceType::VertexType *v = f->V(z);
if (v->VFp()!=0)
{
FaceType *f0=v->VFp();
int z0=v->VFi();
//append
f->VFp(z)=f0;
f->VFi(z)=z0;
}
v->VFp()=f;
v->VFi()=z;
}
/*!
* \brief Compute the set of vertices adjacent to a given vertex using VF adjacency
*
* \param vp pointer to the vertex whose star has to be computed.
* \param starVec a std::vector of Vertex pointer that is filled with the adjacent vertices.
*
*/
template <class FaceType>
void VVStarVF( typename FaceType::VertexType* vp, std::vector<typename FaceType::VertexType *> &starVec)
{
typedef typename FaceType::VertexType* VertexPointer;
starVec.clear();
face::VFIterator<FaceType> vfi(vp);
while(!vfi.End())
{
starVec.push_back(vfi.F()->V1(vfi.I()));
starVec.push_back(vfi.F()->V2(vfi.I()));
++vfi;
}
std::sort(starVec.begin(),starVec.end());
typename std::vector<VertexPointer>::iterator new_end = std::unique(starVec.begin(),starVec.end());
starVec.resize(new_end-starVec.begin());
}
/*!
* \brief Compute the set of faces adjacent to a given vertex using VF adjacency.
*
* \param vp pointer to the vertex whose star has to be computed.
* \param faceVec a std::vector of Face pointer that is filled with the adjacent faces.
* \param indexes a std::vector of integer of the vertex as it is seen from the faces
*/
template <class FaceType>
void VFStarVF( typename FaceType::VertexType* vp,
std::vector<FaceType *> &faceVec,
std::vector<int> &indexes)
{
typedef typename FaceType::VertexType* VertexPointer;
faceVec.clear();
indexes.clear();
face::VFIterator<FaceType> vfi(vp);
while(!vfi.End())
{
faceVec.push_back(vfi.F());
indexes.push_back(vfi.I());
++vfi;
}
}
/*!
* \brief Compute the set of faces incident onto a given edge using FF adjacency.
*
* \param fp pointer to the face whose star has to be computed
* \param ei the index of the edge
* \param faceVec a std::vector of Face pointer that is filled with the faces incident on that edge.
* \param indexes a std::vector of integer of the edge position as it is seen from the faces
*/
template <class FaceType>
void EFStarFF( FaceType* fp, int ei,
std::vector<FaceType *> &faceVec,
std::vector<int> &indVed)
{
assert(fp->FFp(ei)!=0);
faceVec.clear();
indVed.clear();
FaceType* fpit=fp;
int eit=ei;
do
{
faceVec.push_back(fpit);
indVed.push_back(eit);
FaceType *new_fpit = fpit->FFp(eit);
int new_eit = fpit->FFi(eit);
fpit=new_fpit;
eit=new_eit;
} while(fpit != fp);
}
/*!
* Compute the set of faces adjacent to a given vertex using VF adjacency.
* The set is faces is extended of a given number of step
* \param vp pointer to the vertex whose star has to be computed.
* \param num_step the number of step to extend the star
* \param faceVec a std::vector of Face pointer that is filled with the adjacent faces.
*/
template <class FaceType>
static void VFExtendedStarVF(typename FaceType::VertexType* vp,
const int num_step,
std::vector<FaceType*> &faceVec)
{
///initialize front
faceVec.clear();
std::vector<int> indexes;
vcg::face::VFStarVF<FaceType>(vp,faceVec,indexes);
///then dilate front
///for each step
for (int step=0;step<num_step;step++)
{
std::vector<FaceType*> toAdd;
for (unsigned int i=0;i<faceVec.size();i++)
{
FaceType *f=faceVec[i];
for (int k=0;k<3;k++)
{
FaceType *f1=f->FFp(k);
if (f1==f)continue;
toAdd.push_back(f1);
}
}
faceVec.insert(faceVec.end(),toAdd.begin(),toAdd.end());
std::sort(faceVec.begin(),faceVec.end());
typename std::vector<FaceType*>::iterator new_end=std::unique(faceVec.begin(),faceVec.end());
int dist=distance(faceVec.begin(),new_end);
faceVec.resize(dist);
}
}
/*!
* Compute the ordered set of faces adjacent to a given vertex using FF adiacency
* \param startPos a Pos<FaceType> indicating the vertex whose star has to be computed.
* \param faceVec a std::vector of Face pointer that is filled with the adjacent faces.
* \param edgeVec a std::vector of indexes filled with the indexes of the corresponding edges shared between the faces.
*
*/
template <class FaceType>
static void VFOrderedStarFF(Pos<FaceType> &startPos,
std::vector<FaceType*> &faceVec,
std::vector<int> &edgeVec)
{
bool foundBorder=false;
Pos<FaceType> curPos=startPos;
do
{
assert(curPos.IsManifold());
if(curPos.IsBorder()) foundBorder=true;
faceVec.push_back(curPos.F());
edgeVec.push_back(curPos.E());
curPos.FlipF();
curPos.FlipE();
} while(curPos!=startPos);
if(foundBorder)
{
assert((faceVec.size()%2)==0); // if we found a border we visited each face exactly twice.
faceVec.resize(faceVec.size()/2);
edgeVec.resize(edgeVec.size()/2);
}
}
/*!
* Check if two faces share and edge through the FF topology.
* \param f0,f1 the two face to be checked
* \param i0,i1 the index of the shared edge;
*/
template <class FaceType>
bool ShareEdgeFF(FaceType *f0,FaceType *f1, int *i0=0, int *i1=0)
{
assert((!f0->IsD())&&(!f1->IsD()));
for (int i=0;i<3;i++)
if (f0->FFp(i)==f1)
{
if((i0!=0) && (i1!=0)) {
*i0=i;
*i1=f0->FFi(i);
}
return true;
}
return false;
}
/*!
* Count the number of vertices shared between two faces.
* \param f0,f1 the two face to be checked
* ;
*/
template <class FaceType>
int CountSharedVertex(FaceType *f0,FaceType *f1)
{
int sharedCnt=0;
for (int i=0;i<3;i++)
for (int j=0;j<3;j++)
if (f0->V(i)==f1->V(j)) {
sharedCnt++;
}
return sharedCnt;
}
/*!
* find the first shared vertex between two faces.
* \param f0,f1 the two face to be checked
* \param i,j the indexes of the shared vertex in the two faces. Meaningful only if there is one single shared vertex
* ;
*/
template <class FaceType>
bool FindSharedVertex(FaceType *f0,FaceType *f1, int &i, int &j)
{
for (i=0;i<3;i++)
for (j=0;j<3;j++)
if (f0->V(i)==f1->V(j)) return true;
i=-1;j=-1;
return false;
}
/*!
* find the first shared edge between two faces.
* \param f0,f1 the two face to be checked
* \param i,j the indexes of the shared edge in the two faces. Meaningful only if there is a shared edge
*
*/
template <class FaceType>
bool FindSharedEdge(FaceType *f0,FaceType *f1, int &i, int &j)
{
for (i=0;i<3;i++)
for (j=0;j<3;j++)
if( ( f0->V0(i)==f1->V0(j) || f0->V0(i)==f1->V1(j) ) &&
( f0->V1(i)==f1->V0(j) || f0->V1(i)==f1->V1(j) ) )
return true;
i=-1;j=-1;
return false;
}
/*!
* find the faces that shares the two vertices
* \param v0,v1 the two vertices
* \param f0,f1 the two faces , counterclokwise order
*
*/
template <class FaceType>
bool FindSharedFaces(typename FaceType::VertexType *v0,
typename FaceType::VertexType *v1,
FaceType *&f0,
FaceType *&f1,
int &e0,
int &e1)
{
std::vector<FaceType*> faces0;
std::vector<FaceType*> faces1;
VFOrderedStarVF_FF(*v0,faces0);
VFOrderedStarVF_FF(v1,faces1);
///then find the intersection
std::sort(faces0.begin(),faces0.end());
std::sort(faces1.begin(),faces1.end());
std::vector<FaceType*> Intersection;
std::set_intersection(faces0.begin(),faces0.end(),faces1.begin(),faces1.end(),std::back_inserter(Intersection));
if (Intersection.size()<2)return false; ///no pair of faces share the 2 vertices
assert(Intersection.size()==2);//otherwhise non manifoldess
f0=Intersection[0];
f1=Intersection[1];
FindSharedEdge(f0,f1,e0,e1);
///and finally check if the order is right
if (f0->V(e0)!=v0)
{
std::swap(f0,f1);
std::swap(e0,e1);
}
return true;
}
/*@}*/
} // end namespace
} // end namespace
#endif