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/****************************************************************************
History
$Log: not supported by cvs2svn $
Revision 1.28 2006/11/09 17:28:42 cignoni
Corrected Detach; added FFCorrectness; Corrected ComplexSize, Dissemination of a lot of assert()
Revision 1.27 2006/05/03 21:38:57 cignoni
Added possibility of not updating the topology during a SwapEdge
Revision 1.26 2005/12/19 13:47:26 corsini
Rewrite SwapEdge to fix problems with borders
Revision 1.25 2005/12/16 11:01:26 corsini
Remove trivial warnings
Revision 1.24 2005/12/16 10:47:48 corsini
Add further comment to FlipEdge
Revision 1.23 2005/12/16 10:43:23 corsini
Fix one bug
Revision 1.22 2005/12/16 10:29:10 corsini
Add CheckOrientation
Reimplement SwapEdge function
Revision 1.21 2005/12/01 23:54:59 cignoni
Removed excess ';' from end of template functions, for gcc compiling
Revision 1.20 2005/11/23 13:04:26 ganovelli
changed IsBOrder
Revision 1.19 2005/11/10 15:49:32 cignoni
Made IsManifold Constant
Revision 1.18 2005/10/13 08:34:19 cignoni
Removed reference to IsBorder() member of face and substituted with the face templated function version.
Revision 1.17 2005/04/11 09:17:24 pietroni
Changed detach to FFdetach , compiled tested in manifold cases
Revision 1.16 2005/03/18 16:35:53 fiorin
minor changes to comply gcc compiler
Revision 1.15 2004/10/22 13:41:06 fiorin
Added CheckFlipEdge and FlipEdge
Revision 1.14 2004/10/18 17:15:45 ganovelli
minor change
Revision 1.13 2004/08/06 01:47:57 pietroni
corrected errors on vfappend
Revision 1.12 2004/08/05 22:27:00 pietroni
added VFAppend funtion
Revision 1.10 2004/07/27 09:49:23 cignoni
Removed warning about postfix incremnet of VFIterator
Revision 1.9 2004/07/15 12:03:07 ganovelli
minor changes
Revision 1.8 2004/07/15 11:26:48 ganovelli
VFDetach corrected
Revision 1.7 2004/05/12 12:23:23 cignoni
Conformed C++ syntax to GCC requirements
Revision 1.6 2004/05/11 16:03:18 ganovelli
changed from "thi" to "&f" in Vfdetach
Revision 1.5 2004/05/10 15:20:49 cignoni
Updated names of POS and adj functions to the new standards for many functions
Revision 1.4 2004/03/18 16:00:10 cignoni
minor changes
****************************************************************************/
#ifndef _VCG_FACE_TOPOLOGY
#define _VCG_FACE_TOPOLOGY
#include <vcg/simplex/face/pos.h>
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 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(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(*LastFace.f,LastFace.z));
assert(FFCorrectness(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 Attach(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;
}
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);
}
// Funzione di supporto usata da swap?
//template <class FaceType>
//inline void Nexts( *&f, int &z )
//{
// int t;
// t = z;
// z = (*f).Z(z);
// f = (*f).F(t);
//}
/**
* 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)
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;
}
}
/*!
* Check if the z-th edge of the face f can be flipped.
* \param f pointer to the face
* \param z the edge index
*/
template <class FaceType>
static bool CheckFlipEdge(FaceType &f, int z)
{
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
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
typedef typename FaceType::VertexType VertexType;
VertexType *f_v2 = f.V2(z);
VertexType *g_v2 = g->V2(w);
if (f_v2 == g_v2)
return false;
vcg::face::Pos< FaceType > pos(&f, (z+2)%3, f.V2(z));
do
{
pos.NextE();
if (g_v2==pos.f->V1(pos.z))
return false;
}
while (&f!=pos.f);
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->FFp1(w);
f.FFi(z) = g->FFi((w+1)%3);
g->FFp(w) = f.FFp1(z);
g->FFi(w) = f.FFi((z+1)%3);
f.FFp1(z) = g;
f.FFi((z+1)%3) = (w+1)%3;
g->FFp1(w) = &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;
}
}
// 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::VerteType *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;
}
/*@}*/
} // end namespace
} // end namespace
#endif