vcglib/vcg/complex/algorithms/crease_cut.h

/****************************************************************************
* VCGLib                                                            o o     *
* Visual and Computer Graphics Library                            o     o   *
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* Copyright(C) 2008                                                \/)\/    *
* Visual Computing Lab                                            /\/|      *
* ISTI - Italian National Research Council                           |      *
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* 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_CREASE_CUT
#define __VCG_CREASE_CUT
#include<vcg/simplex/face/jumping_pos.h>
#include<vcg/complex/algorithms/update/normal.h>
namespace vcg {
namespace tri {

/*
Crease Angle
Assume che:
la mesh abbia la topologia ff
la mesh non abbia complex (o se li aveva fossero stati detached)
Abbia le normali per faccia normalizzate!!


Prende una mesh e duplica tutti gli edge le cui normali nelle facce incidenti formano un angolo maggiore
di <angle> (espresso in rad).
foreach face
 foreach unvisited vert vi
   scan the star of triangles around vi duplicating vi each time we encounter a crease angle.

the new (and old) vertexes are put in a std::vector that is swapped with the original one at the end.

Si tiene un vettore di interi 3 *fn che dice l'indice del vertice puntato da ogni faccia.
quando si scandisce la stella intorno ad un vertici, per ogni wedge si scrive l'indice del vertice corrsipondente.


*/

template<class MESH_TYPE>
void CreaseCut(MESH_TYPE &m, float angleRad)
{
	typedef typename MESH_TYPE::CoordType				CoordType;
	typedef typename MESH_TYPE::ScalarType			ScalarType;
	typedef typename MESH_TYPE::VertexType			VertexType;
	typedef typename MESH_TYPE::VertexPointer		VertexPointer;
	typedef typename MESH_TYPE::VertexIterator	VertexIterator;
	typedef typename MESH_TYPE::FaceIterator		FaceIterator;
	typedef typename MESH_TYPE::FaceType				FaceType;
	typedef typename MESH_TYPE::FacePointer		FacePointer;

	tri::Allocator<MESH_TYPE>::CompactVertexVector(m);
	tri::Allocator<MESH_TYPE>::CompactFaceVector(m);

	tri::UpdateNormal<MESH_TYPE>::NormalizePerFace(m);

  assert(tri::HasFFAdjacency(m));
  typename MESH_TYPE::ScalarType cosangle=math::Cos(angleRad);

	tri::UpdateFlags<MESH_TYPE>::VertexClearV(m);
	std::vector<int> indVec(m.fn*3,-1);
	int newVertexCounter=m.vn;
	int startVn=m.vn;
	for(FaceIterator fi=m.face.begin();fi!=m.face.end();++fi)
		 for(int j=0;j<3;++j)
				if(!(*fi).V(j)->IsV() )  // foreach unvisited vertex we loop around it searching for creases.
					{
						(*fi).V(j)->SetV();

					face::JumpingPos<FaceType> iPos(&*fi,j,(*fi).V(j));
						size_t vertInd = Index(m,iPos.v);	 //
						bool isBorderVertex = iPos.FindBorder();   // for border vertex we start from the border.
						face::JumpingPos<FaceType> startPos=iPos;
						if(!isBorderVertex)                        // for internal vertex we search the first crease and start from it
								{
									do {
												ScalarType dotProd = iPos.FFlip()->cN().dot(iPos.f->N());
												iPos.NextFE();
												if(dotProd<cosangle) break;
									} while (startPos!=iPos);
									startPos=iPos;                       // the found crease become the new starting pos.
								}

						int locCreaseCounter=0;
						int curVertexCounter =vertInd;

						do {																													// The real Loop
								ScalarType dotProd=iPos.FFlip()->cN().dot(iPos.f->N());			// test normal with the next face (fflip)
								size_t faceInd = Index(m,iPos.f);
								indVec[faceInd*3+ iPos.VInd()] = curVertexCounter;

								if(dotProd<cosangle)
											{ //qDebug("  Crease FOUND");
											++locCreaseCounter;
												curVertexCounter=newVertexCounter;
												newVertexCounter++;
											}
								iPos.NextFE();
						} while (startPos!=iPos);
						if(locCreaseCounter>0 && (!isBorderVertex) ) newVertexCounter--;
					}

	// A questo punto ho un vettore che mi direbbe per ogni faccia quale vertice devo mettere. Dopo che ho aggiunto i vertici necessari,
	// rifaccio il giro delle facce
	//qDebug("adding %i vert for %i crease edges ",newVertexCounter-m.vn, creaseCounter);
	tri::Allocator<MESH_TYPE>::AddVertices(m,newVertexCounter-m.vn);

	tri::UpdateFlags<MESH_TYPE>::VertexClearV(m);
	for(FaceIterator fi=m.face.begin();fi!=m.face.end();++fi)
		for(int j=0;j<3;++j) // foreach unvisited vertex
		{
			size_t faceInd = Index(m, *fi);
			size_t vertInd = Index(m, (*fi).V(j));
			int curVertexInd = indVec[faceInd*3+ j];
			assert(curVertexInd != -1);
			assert(curVertexInd < m.vn);
			if(curVertexInd < startVn) assert(size_t(curVertexInd) == vertInd);
			if(curVertexInd >= startVn)
				{
					m.vert[curVertexInd].ImportData(*((*fi).V(j)));
					(*fi).V(j) = & m.vert[curVertexInd];
				}
		}
		tri::UpdateNormal<MESH_TYPE>::PerVertexFromCurrentFaceNormal(m);
}

} // end namespace tri
} // end namespace vcg
#endif