passed to new container format for plyptm : good for glsl (only vec3)

include/Algo/Decimation/approximator.h

@@ -44,6 +44,7 @@ enum ApproximatorType
 	A_CornerCutting,
 	A_TangentPredict1,
 	A_TangentPredict2,
+	A_LightfieldHalf,
 	A_LightfieldFull
 } ;
 

include/Algo/Decimation/decimation.hpp

@@ -71,11 +71,11 @@ void decimate(
 		}
 		case A_LightfieldHalf :
 		{
-			approximators.push_back(new Approximator_QEM<PFP>(map, position)) ;
+			approximators.push_back(new Approximator_HalfCollapse<PFP>(map, position)) ;
 			AttributeHandler<Geom::Matrix<3,3,typename PFP::REAL> > frame = map.template getAttribute<Geom::Matrix<3,3,typename PFP::REAL> >(VERTEX_ORBIT, "frame") ;
 			AttributeHandler<Geom::Matrix<3,6,typename PFP::REAL> > RGBfunctions = map.template getAttribute<Geom::Matrix<3,6,typename PFP::REAL> >(VERTEX_ORBIT, "colorPTM") ;
 			approximators.push_back(new Approximator_FrameHalf<PFP>(map, frame)) ;
-			approximators.push_back(new Approximator_RGBfunctions<PFP>(map, RGBfunctions)) ;
+			approximators.push_back(new Approximator_RGBfunctionsHalf<PFP>(map, RGBfunctions)) ;
 			break ;
 		}
 	}
@@ -91,12 +91,18 @@ void decimate(
 		case S_EdgeLength :
 			selector = new EdgeSelector_Length<PFP>(map, position, approximators) ;
 			break ;
+		case S_QEMml :
+			selector = new EdgeSelector_QEMml<PFP>(map, position, approximators) ;
+			break ;
 		case S_QEM :
 			selector = new EdgeSelector_QEM<PFP>(map, position, approximators) ;
 			break ;
 		case S_Lightfield :
 			selector = new EdgeSelector_Lightfield<PFP>(map, position, approximators) ;
 			break ;
+		case S_LightfieldHalf :
+			selector = new HalfEdgeSelector_Lightfield<PFP>(map, position, approximators) ;
+			break ;
 		case S_Curvature :
 			selector = new EdgeSelector_Curvature<PFP>(map, position, approximators) ;
 			break ;

include/Algo/Decimation/lightfieldApproximator.h

@@ -36,6 +36,55 @@ namespace Algo
 namespace Decimation
 {
 
+template <typename PFP>
+class Approximator_FrameHalf : public Approximator<PFP, typename Geom::Matrix<3,3,typename PFP::REAL> >
+{
+public:
+	typedef typename PFP::MAP MAP ;
+	typedef typename PFP::VEC3 VEC3 ;
+	typedef typename PFP::REAL REAL ;
+
+	typedef Geom::Matrix<3,3,REAL> MATRIX33 ;
+	typedef Geom::Matrix<3,6,REAL> MATRIX36 ;
+
+public:
+	Approximator_FrameHalf(MAP& m, AttributeHandler<MATRIX33>& frame, Predictor<PFP, MATRIX33>* pred = NULL) :
+		Approximator<PFP, MATRIX33>(m, frame, EDGE_ORBIT, pred)
+	{}
+	~Approximator_FrameHalf()
+	{}
+	ApproximatorType getType() const { return A_LightfieldHalf ; }
+	bool init() { return true ; } ;
+	void approximate(Dart d) ;
+} ;
+
+template <typename PFP>
+class Approximator_RGBfunctionsHalf : public Approximator<PFP, typename Geom::Matrix<3,6,typename PFP::REAL> >
+{
+public:
+	typedef typename PFP::MAP MAP ;
+	typedef typename PFP::VEC3 VEC3 ;
+	typedef typename PFP::REAL REAL ;
+
+	typedef Geom::Matrix<3,3,REAL> MATRIX33 ;
+	typedef Geom::Matrix<3,6,REAL> MATRIX36 ;
+
+protected:
+	AttributeHandler<MATRIX33> m_frame ;
+	AttributeHandler<MATRIX33> m_approxFrame ;
+	AttributeHandler<QuadricRGBfunctions<REAL> > m_quadricRGBfunctions ;
+
+public:
+	Approximator_RGBfunctionsHalf(MAP& m, AttributeHandler<MATRIX36>& rgbfunctions, Predictor<PFP, MATRIX36>* pred = NULL) :
+		Approximator<PFP, MATRIX36>(m, rgbfunctions, EDGE_ORBIT, pred)
+	{ }
+	~Approximator_RGBfunctionsHalf	()
+	{}
+	ApproximatorType getType() const { return A_LightfieldHalf ; }
+	bool init() ;
+	void approximate(Dart d) ;
+} ;
+
 template <typename PFP>
 class Approximator_Frame : public Approximator<PFP, typename Geom::Matrix<3,3,typename PFP::REAL> >
 {

include/Algo/Decimation/lightfieldApproximator.hpp

@@ -31,6 +31,96 @@ namespace Algo
 namespace Decimation
 {
 
+/************************************************************************************
+ *                      LIGHTFIELD QUADRIC METRIC : frame                           *
+ ************************************************************************************/
+
+template <typename PFP>
+void Approximator_FrameHalf<PFP>::approximate(Dart d)
+{
+	this->m_approx[d] = this->m_attrV[d] ;
+}
+
+/************************************************************************************
+ *                      LIGHTFIELD QUADRIC METRIC : functions                       *
+ ************************************************************************************/
+
+template <typename PFP>
+bool Approximator_RGBfunctionsHalf<PFP>::init()
+{
+	// get actual frames and hypothetical approximated frames
+	m_frame = this->m_map.template getAttribute<MATRIX33>(VERTEX_ORBIT, "frame") ;
+	m_approxFrame = this->m_map.template getAttribute<MATRIX33>(EDGE_ORBIT, "approx_frame") ;
+	m_quadricRGBfunctions = this->m_map.template getAttribute<QuadricRGBfunctions<REAL> >(EDGE_ORBIT, "quadricRGBfunctions") ;
+
+	MapBrowserLinkedAuto<typename PFP::MAP> mb(this->m_map) ;
+	this->m_map.foreach_orbit(EDGE_ORBIT, mb) ;
+
+	// create quadric embedding for computing and set them to 0
+	for (Dart d = mb.begin() ; d != mb.end() ; mb.next(d))
+		m_quadricRGBfunctions[d].zero() ;
+
+	// Check on embeddings
+	if (!m_frame.isValid() || !m_approxFrame.isValid() || !m_quadricRGBfunctions.isValid())
+	{
+		std::cerr << "Approximator_RGBfunctions::init() --> No approxPosition or no quadricRGBfunctions specified" << std::endl ;
+		return false ;
+	}
+
+	return true ;
+}
+
+template <typename PFP>
+void Approximator_RGBfunctionsHalf<PFP>::approximate(Dart d)
+{
+	MAP& m = this->m_map ;
+	Dart dd = m.phi2(d) ;	// get the two vertices
+
+	// Approximation
+	this->m_approx[d] = this->m_attrV[d] ;
+
+	// Compute quadrics for error evaluation
+	// get hypothetical local frames
+	VEC3 i,n ;
+
+	m_approxFrame[d].getSubVectorH(0,0,i) ;
+	m_approxFrame[d].getSubVectorH(2,0,n) ;
+
+	// Get previous local frames
+	VEC3 n1,n2,i1,i2,j1,j2 ;
+
+	m_frame[d].getSubVectorH(0,0,i1) ;
+	m_frame[dd].getSubVectorH(0,0,i2) ;
+
+	m_frame[d].getSubVectorH(1,0,j1) ;
+	m_frame[dd].getSubVectorH(1,0,j2) ;
+
+	m_frame[d].getSubVectorH(2,0,n1) ;
+	m_frame[dd].getSubVectorH(2,0,n2) ;
+
+	// Compute j1' and j2'
+	VEC3 j1pr = n1 ^ i ;
+	j1pr.normalize() ;
+	VEC3 j2pr = n2 ^ i ;
+	j2pr.normalize() ;
+
+	// Rotation dans sens trigo dans le plan tangent autour de n (i1->i)
+//	REAL gamma1 = ((j1 * i) > 0 ? 1 : -1) * acos( std::max(std::min(1.0f, i1 * i ), -1.0f)) ; // angle positif ssi
+	REAL gamma2 = ((j2 * i) > 0 ? 1 : -1) * acos( std::max(std::min(1.0f, i2 * i ), -1.0f)) ; // -PI/2 < angle(i,j1) < PI/2  ssi i*j1 > 0
+	// Rotation dans le sens trigo autour de l'axe i (n1->n)
+//	REAL alpha1 = ((n * j1pr) > 0 ? -1 : 1) * acos( std::max(std::min(1.0f, n * n1), -1.0f) ) ; // angle positif ssi
+	REAL alpha2 = ((n * j2pr) > 0 ? -1 : 1) * acos( std::max(std::min(1.0f, n * n2), -1.0f) ) ; // PI/2 < angle(j1',n) < -PI/2 ssi j1'*n < 0
+
+//	assert (-0.01 < gamma1 && gamma1 < 0.01) ;
+//	assert (-0.01 < alpha1 && alpha1 < 0.01) ;
+	REAL gamma1 = REAL(0) ;
+	REAL alpha1 = REAL(0) ;
+
+	// Create and sum quadrics
+	m_quadricRGBfunctions[d] += QuadricRGBfunctions<REAL>(this->m_attrV[d], gamma1, alpha1) ;
+	m_quadricRGBfunctions[d] += QuadricRGBfunctions<REAL>(this->m_attrV[dd], gamma2, alpha2) ;
+}
+
 /************************************************************************************
  *                      LIGHTFIELD QUADRIC METRIC : frame                           *
  ************************************************************************************/
@@ -106,8 +196,11 @@ bool Approximator_RGBfunctions<PFP>::init()
 	m_approxFrame = this->m_map.template getAttribute<MATRIX33>(EDGE_ORBIT, "approx_frame") ;
 	m_quadricRGBfunctions = this->m_map.template getAttribute<QuadricRGBfunctions<REAL> >(EDGE_ORBIT, "quadricRGBfunctions") ;
 
+	MapBrowserLinkedAuto<typename PFP::MAP> mb(this->m_map) ;
+	this->m_map.foreach_orbit(EDGE_ORBIT, mb) ;
+
 	// create quadric embedding for computing and set them to 0
-	for (Dart d = this->m_map.begin() ; d != this->m_map.end() ; this->m_map.next(d))
+	for (Dart d = mb.begin() ; d != mb.end() ; mb.next(d))
 		m_quadricRGBfunctions[d].zero() ;
 
 	// Check on embeddings

include/Algo/Decimation/selector.h

@@ -46,9 +46,11 @@ enum SelectorType
 	S_Random,
 	S_EdgeLength,
 	S_QEM,
+	S_QEMml,
 	S_MinDetail,
 	S_Curvature,
-	S_Lightfield
+	S_Lightfield,
+	S_LightfieldHalf
 } ;
 
 
@@ -228,6 +230,120 @@ public:
 	void updateAfterCollapse(Dart d2, Dart dd2) ;
 } ;
 
+template <typename PFP>
+class EdgeSelector_QEMml : public EdgeSelector<PFP>
+{
+public:
+	typedef typename PFP::MAP MAP ;
+	typedef typename PFP::VEC3 VEC3 ;
+	typedef typename PFP::REAL REAL ;
+
+private:
+	typedef	struct
+	{
+		typename std::multimap<float,Dart>::iterator it ;
+		bool valid ;
+		static std::string CGoGNnameOfType() { return "QEMedgeInfo" ; }
+	} QEMedgeInfo ;
+	typedef NoMathIOAttribute<QEMedgeInfo> EdgeInfo ;
+
+	AttributeHandler<EdgeInfo> edgeInfo ;
+	AttributeHandler<Quadric<REAL> > quadric ;
+
+	std::multimap<float,Dart> edges ;
+	typename std::multimap<float,Dart>::iterator cur ;
+
+	Approximator<PFP, typename PFP::VEC3>* m_positionApproximator ;
+
+	void initEdgeInfo(Dart d) ;
+	void updateEdgeInfo(Dart d, bool recompute) ;
+	void computeEdgeInfo(Dart d, EdgeInfo& einfo) ;
+	void recomputeQuadric(const Dart d, const bool neighbours = false) ;
+	Dart rewind(const Dart d) ;
+
+public:
+	EdgeSelector_QEMml(MAP& m, typename PFP::TVEC3& pos, std::vector<ApproximatorGen<PFP>*>& approx, const FunctorSelect& select = SelectorTrue()) :
+		EdgeSelector<PFP>(m, pos, approx, select)
+	{
+		edgeInfo = m.template addAttribute<EdgeInfo>(EDGE_ORBIT, "edgeInfo") ;
+		quadric = m.template addAttribute<Quadric<REAL> >(VERTEX_ORBIT, "QEMquadric") ;
+	}
+	~EdgeSelector_QEMml()
+	{
+		this->m_map.removeAttribute(quadric) ;
+		this->m_map.removeAttribute(edgeInfo) ;
+	}
+	SelectorType getType() { return S_QEM ; }
+	bool init() ;
+	bool nextEdge(Dart& d) ;
+	void updateBeforeCollapse(Dart d) ;
+	void updateAfterCollapse(Dart d2, Dart dd2) ;
+} ;
+
+template <typename PFP>
+class HalfEdgeSelector_Lightfield : public EdgeSelector<PFP>
+{
+public:
+	typedef typename PFP::MAP MAP ;
+	typedef typename PFP::VEC3 VEC3 ;
+	typedef typename PFP::REAL REAL ;
+
+	typedef Geom::Matrix<3,3,REAL> MATRIX33 ;
+	typedef MATRIX33 FRAME ;
+	typedef Geom::Matrix<3,6,REAL> MATRIX36 ;
+	typedef MATRIX36 RGBFUNCTIONS ;
+
+private:
+	typedef	struct
+	{
+		typename std::multimap<float,Dart>::iterator it ;
+		bool valid ;
+		static std::string CGoGNnameOfType() { return "LightfieldHalfEdgeInfo" ; }
+	} LightfieldHalfEdgeInfo ;
+	typedef NoMathIOAttribute<LightfieldHalfEdgeInfo> HalfEdgeInfo ;
+
+	AttributeHandler<FRAME > m_frame ;
+
+	AttributeHandler<HalfEdgeInfo> halfEdgeInfo ;
+	AttributeHandler<Quadric<REAL> > quadric ;
+	AttributeHandler<QuadricRGBfunctions<REAL> > quadricRGBfunctions ;
+
+	std::multimap<float,Dart> halfEdges ;
+	typename std::multimap<float,Dart>::iterator cur ;
+
+	Approximator<PFP, VEC3>* m_positionApproximator ;
+	Approximator<PFP, FRAME >* m_frameApproximator ;
+	Approximator<PFP, RGBFUNCTIONS >* m_RGBfunctionsApproximator ;
+
+	void initHalfEdgeInfo(Dart d) ;
+	void updateHalfEdgeInfo(Dart d, bool recompute) ;
+	void computeHalfEdgeInfo(Dart d, HalfEdgeInfo& einfo) ;
+	void recomputeQuadric(const Dart d, const bool neighbors) ;
+	Dart rewind(const Dart d) ;
+
+public:
+	HalfEdgeSelector_Lightfield(MAP& m, typename PFP::TVEC3& pos, std::vector<ApproximatorGen<PFP>*>& approx, const FunctorSelect& select = SelectorTrue()) :
+		EdgeSelector<PFP>(m, pos, approx, select)
+	{
+		m_frame = m.template getAttribute<FRAME>(VERTEX_ORBIT, "frame") ;
+
+		halfEdgeInfo = m.template addAttribute<HalfEdgeInfo>(DART_ORBIT, "halfEdgeInfo") ;
+		quadric = m.template addAttribute<Quadric<REAL> >(VERTEX_ORBIT, "QEMquadric") ;
+		quadricRGBfunctions = m.template addAttribute<QuadricRGBfunctions<REAL> >(EDGE_ORBIT, "quadricRGBfunctions") ;
+	}
+	~HalfEdgeSelector_Lightfield()
+	{
+		this->m_map.removeAttribute(quadric) ;
+		this->m_map.removeAttribute(quadricRGBfunctions) ;
+		this->m_map.removeAttribute(halfEdgeInfo) ;
+	}
+	SelectorType getType() { return S_Lightfield ; }
+	bool init() ;
+	bool nextEdge(Dart& d) ;
+	void updateBeforeCollapse(Dart d) ;
+	void updateAfterCollapse(Dart d2, Dart dd2) ;
+} ;
+
 template <typename PFP>
 class EdgeSelector_Lightfield : public EdgeSelector<PFP>
 {

include/Algo/Decimation/selector.hpp

@@ -404,9 +404,9 @@ void EdgeSelector_QEM<PFP>::updateAfterCollapse(Dart d2, Dart dd2)
 			do											// - edges for which only the collapsibility must be re-tested
 			{
 				updateEdgeInfo(vit2, false) ;
-				updateEdgeInfo(m.phi1(vit2), false) ;
+				updateEdgeInfo(m.phi1(vit2), false) ; // OPTIM POSSIBLE : ne pas faire le 1er phi1(vit2) (car sera fait dans prochaine itération) ?
 				vit2 = m.alpha_1(vit2) ;
-			} while(vit2 != stop) ;
+			} while(vit2 != stop) ;	// OPTIM POSSIBLE : ne pas faire vit2 == stop (car déjà fait dans initEdgeInfo(vit)) ?
 		}
 		else
 			updateEdgeInfo(vit, true) ;
@@ -478,6 +478,537 @@ void EdgeSelector_QEM<PFP>::computeEdgeInfo(Dart d, EdgeInfo& einfo)
 	einfo.valid = true ;
 }
 
+/************************************************************************************
+ *                            QUADRIC ERROR METRIC (Memoryless version)             *
+ ************************************************************************************/
+
+template <typename PFP>
+bool EdgeSelector_QEMml<PFP>::init()
+{
+	MAP& m = this->m_map ;
+
+	bool ok = false ;
+	for(typename std::vector<ApproximatorGen<PFP>*>::iterator it = this->m_approximators.begin();
+		it != this->m_approximators.end() && !ok;
+		++it)
+	{
+		if((*it)->getApproximatedAttributeName() == "position")
+		{
+			m_positionApproximator = reinterpret_cast<Approximator<PFP, VEC3>* >(*it) ;
+			ok = true ;
+		}
+	}
+
+	if(!ok)
+		return false ;
+
+	edges.clear() ;
+
+	CellMarker vMark(m, VERTEX_CELL) ;
+	for(Dart d = m.begin(); d != m.end(); m.next(d))
+	{
+		if(!vMark.isMarked(d))
+		{
+			Quadric<REAL> q ;	// create one quadric
+			quadric[d] = q ;	// per vertex
+			vMark.mark(d) ;
+		}
+	}
+
+	DartMarker mark(m) ;
+	for(Dart d = m.begin(); d != m.end(); m.next(d))
+	{
+		if(!mark.isMarked(d))
+		{
+			Dart d1 = m.phi1(d) ;				// for each triangle,
+			Dart d_1 = m.phi_1(d) ;				// initialize the quadric of the triangle
+			Quadric<REAL> q(this->m_position[d], this->m_position[d1], this->m_position[d_1]) ;
+			quadric[d] += q ;					// and add the contribution of
+			quadric[d1] += q ;					// this quadric to the ones
+			quadric[d_1] += q ;					// of the 3 incident vertices
+			mark.markOrbit(FACE_ORBIT, d) ;
+		}
+	}
+
+	CellMarker eMark(m, EDGE_CELL) ;
+	for(Dart d = m.begin(); d != m.end(); m.next(d))
+	{
+		if(!eMark.isMarked(d))
+		{
+			initEdgeInfo(d) ;	// init the edges with their optimal position
+			eMark.mark(d) ;		// and insert them in the multimap according to their error
+		}
+	}
+
+	cur = edges.begin() ; // init the current edge to the first one
+
+	return true ;
+}
+
+template <typename PFP>
+bool EdgeSelector_QEMml<PFP>::nextEdge(Dart& d)
+{
+	if(cur == edges.end() || edges.empty())
+		return false ;
+	d = (*cur).second ;
+	return true ;
+}
+
+template <typename PFP>
+void EdgeSelector_QEMml<PFP>::updateBeforeCollapse(Dart d)
+{
+	MAP& m = this->m_map ;
+
+	EdgeInfo& edgeE = edgeInfo[d] ;
+	if(edgeE.valid)
+		edges.erase(edgeE.it) ;
+
+	edgeE = edgeInfo[m.phi1(d)] ;
+	if(edgeE.valid)					// remove all
+		edges.erase(edgeE.it) ;
+
+	edgeE = edgeInfo[m.phi_1(d)] ;	// the concerned edges
+	if(edgeE.valid)
+		edges.erase(edgeE.it) ;
+									// from the multimap
+	Dart dd = m.phi2(d) ;
+	if(dd != d)
+	{
+		edgeE = edgeInfo[m.phi1(dd)] ;
+		if(edgeE.valid)
+			edges.erase(edgeE.it) ;
+
+		edgeE = edgeInfo[m.phi_1(dd)] ;
+		if(edgeE.valid)
+			edges.erase(edgeE.it) ;
+	}
+
+}
+
+/**
+ *  rewind until border (if any)
+ */
+// TODO : check & optimize
+template <typename PFP>
+Dart EdgeSelector_QEMml<PFP>::rewind(const Dart d) {
+	Dart dInit = d ;
+	do {
+		if (dInit == this->m_map.phi2(dInit)) // if border
+			break ; // stop
+		dInit = this->m_map.alpha_1(dInit) ;
+	} while (dInit != d) ;
+
+	return dInit ;
+}
+
+/**
+ * Update quadric of a vertex
+ * Discards quadrics of d and assigns freshly calculated
+ * quadrics depending on the actual planes surrounding d
+ * @param dart d
+ */
+template <typename PFP>
+void EdgeSelector_QEMml<PFP>::recomputeQuadric(const Dart d, const bool neighbours) {
+	Dart dFront,dBack;
+	Dart dInit = rewind(d) ; // rewind until border (if any)
+
+	// Init Front
+	dFront = dInit;
+
+	quadric[d].zero();
+
+   	do {
+   		// Make step
+   		dBack = dFront ;
+       	dFront = this->m_map.alpha1(dFront);
+
+       	if (neighbours)
+       		recomputeQuadric(this->m_map.phi2(dFront), false) ;
+
+       	if (dFront == this->m_map.phi2(dFront))
+       		break ;
+
+       	quadric[d] += Quadric<REAL>(this->m_position[d],this->m_position[this->m_map.phi2(dFront)],this->m_position[this->m_map.phi2(dBack)]);
+
+    } while(dFront != dInit);
+}
+
+
+template <typename PFP>
+void EdgeSelector_QEMml<PFP>::updateAfterCollapse(Dart d2, Dart dd2)
+{
+	MAP& m = this->m_map ;
+
+	// for local vertex and neighbors
+	recomputeQuadric(d2, true) ;
+
+	Dart vit = d2 ;
+	do
+	{
+		updateEdgeInfo(m.phi1(vit), true) ;			// must recompute some edge infos in the
+		if(vit == d2 || vit == dd2)					// neighborhood of the collapsed edge
+			initEdgeInfo(vit) ;						// various optimizations are applied here by
+		else										// treating differently :
+			updateEdgeInfo(vit, true) ;
+
+		Dart vit2 = m.alpha_1(m.phi1(vit)) ;		// - edges for which the criteria must be recomputed
+		Dart stop = m.phi2(vit) ;					// - edges that must be re-embedded
+		do											// - edges for which only the collapsibility must be re-tested
+		{
+			updateEdgeInfo(vit2, true) ;
+			updateEdgeInfo(m.phi1(vit2), false) ;
+			vit2 = m.alpha_1(vit2) ;	// OPTIM POSSIBLE : ne pas faire vit2 == stop car déjà fait dans init/updateEdgeInfo(vit)
+		} while(vit2 != stop) ;
+
+		vit = m.alpha1(vit) ;
+	} while(vit != d2) ;
+
+	cur = edges.begin() ; // set the current edge to the first one
+}
+
+template <typename PFP>
+void EdgeSelector_QEMml<PFP>::initEdgeInfo(Dart d)
+{
+	MAP& m = this->m_map ;
+	EdgeInfo einfo ;
+	if(m.edgeCanCollapse(d))
+		computeEdgeInfo(d, einfo) ;
+	else
+		einfo.valid = false ;
+	edgeInfo[d] = einfo ;
+}
+
+template <typename PFP>
+void EdgeSelector_QEMml<PFP>::updateEdgeInfo(Dart d, bool recompute)
+{
+	MAP& m = this->m_map ;
+	EdgeInfo& einfo = edgeInfo[d] ;
+	if(recompute)
+	{
+		if(einfo.valid)
+			edges.erase(einfo.it) ;		// remove the edge from the multimap
+		if(m.edgeCanCollapse(d))
+			computeEdgeInfo(d, einfo) ;
+		else
+			einfo.valid = false ;
+	}
+	else
+	{
+		if(m.edgeCanCollapse(d))
+		{								 	// if the edge can be collapsed now
+			if(!einfo.valid)				// but it was not before
+				computeEdgeInfo(d, einfo) ;
+		}
+		else
+		{								 // if the edge cannot be collapsed now
+			if(einfo.valid)				 // and it was before
+			{
+				edges.erase(einfo.it) ;
+				einfo.valid = false ;
+			}
+		}
+	}
+}
+