Merge cgogn:~vanhoey/CGoGN

Conflicts:
	src/Utils/textureSticker.cpp

CMakeLists.txt

@@ -104,7 +104,7 @@ ENDIF (WITH_ZINRI)
 
 IF (WITH_QT)
 	add_definitions(-DWITH_QT)
-	find_package(Qt4 REQUIRED)
+	find_package(Qt REQUIRED)
 	SET(QT_USE_QTCORE TRUE)
 	SET(QT_USE_QTOPENGL TRUE)
 	SET(QT_USE_QTSVG TRUE)

include/Algo/Decimation/approximator.h

 /*******************************************************************************
 * CGoGN: Combinatorial and Geometric modeling with Generic N-dimensional Maps  *
 * version 0.1                                                                  *
-* Copyright (C) 2009-2012, IGG Team, LSIIT, University of Strasbourg           *
+* Copyright (C) 2009-2013, IGG Team, ICube, University of Strasbourg           *
 *                                                                              *
 * This library is free software; you can redistribute it and/or modify it      *
 * under the terms of the GNU Lesser General Public License as published by the *
@@ -41,21 +41,32 @@ namespace Decimation
 
 enum ApproximatorType
 {
-	A_QEM,
-	A_MidEdge,
-	A_CornerCutting,
-	A_TangentPredict1,
-	A_TangentPredict2,
-	A_NormalArea,
-	A_ColorNaive,
-	A_ColorQEMext,
-	A_Lightfield,
-	// note: the following "h" prefix means that half-edges are prioritized instead of edges.
-	A_hHalfCollapse,
-	A_hQEM,
-	A_hLightfieldHalf
+	// One approx per edge
+	// Geometry approximators
+	A_QEM = 0, /**< Approximates the geometry of an edge collapse by quadric error metric minimization [GH97]. */
+	A_MidEdge = 1, /**< Approximates the geometry of an edge collapse by placing the resulting vertex in its middle. */
+	A_CornerCutting = 2,
+	A_TangentPredict1 = 3,
+	A_TangentPredict2 = 4,
+	A_NormalArea = 5, /**< EXPERIMENTAL Approximates the geometry of an edge collapse by minimization of its normal times area measure [Sauvage] */
+	// Geometry + color approximators
+	A_ColorNaive = 6, /**< Approximates the color of the resulting vertex by linear interpolation (based on the approximated position) of its two predecessors. */
+	A_ColorQEMext = 7, /**< Approximates both geometry and color of the resulting vertex by minimization of the extended (R^6) quadric error metric [GH98]. */
+	A_GeomColorOpt = 8, /**< EXPERIMENTAL. */
+
+	// One approx per half-edge
+	// Generic (considers all provided attributes) approximator
+	A_hHalfCollapse = 9, /**< Approximates all provided attributes of a half-edge collapse by keeping the attributes of the first of two vertices. */
+	// Geometry approximator
+	A_hQEM = 10, /**< Approximates the geometry of a full-edge collapse by quadric error metric minimization [GH97]. Compatible version for half-edge selectors. */
+
+	A_OTHER /**< Can be used for extensions. */
 } ;
 
+/*!
+ * \class ApproximatorGen
+ * \brief Generic class holder for approximators
+ */
 template <typename PFP>
 class ApproximatorGen
 {
@@ -73,7 +84,6 @@ public:
 	virtual ~ApproximatorGen()
 	{}
 	virtual const std::string& getApproximatedAttributeName(unsigned int index = 0) const = 0 ;
-//	virtual std::vector<std::string> getApproximatedAttributeNames() const = 0 ;
 	virtual ApproximatorType getType() const = 0 ;
 	virtual unsigned int getNbApproximated() const = 0 ;
 	virtual bool init() = 0 ;
@@ -86,6 +96,10 @@ public:
 } ;
 
 
+/*!
+ * \class Approximator
+ * \brief Generic class for approximators
+ */
 template <typename PFP, typename T, unsigned int ORBIT>
 class Approximator : public ApproximatorGen<PFP>
 {
@@ -103,163 +117,33 @@ protected:
 	std::vector<T> m_app ;
 
 public:
-	Approximator(MAP& m, std::vector<VertexAttribute<T>* > va, Predictor<PFP, T> * predictor) :
-		ApproximatorGen<PFP>(m), m_predictor(predictor), m_attrV(va)
-	{
-		const unsigned int& size = m_attrV.size() ;
-		assert(size > 0 || !"Approximator: no attributes provided") ;
-
-		m_approx.resize(size) ;
-		m_detail.resize(size) ;
-		m_app.resize(size) ;
-
-		for (unsigned int i = 0 ; i < size ; ++i)
-		{
-			if (!m_attrV[i]->isValid())
-				std::cerr << "Approximator Warning: attribute number " << i << " is not valid" << std::endl ;
-
-			std::stringstream aname ;
-			aname << "approx_" << m_attrV[i]->name() ;
-			m_approx[i] = this->m_map.template addAttribute<T, ORBIT>(aname.str()) ;
-
-			if(m_predictor)	// if predictors are associated to the approximator
-			{				// create attributes to store the details needed for reconstruction
-				std::stringstream dname ;
-				dname << "detail_" << m_attrV[i]->name() ;
-				m_detail[i] = this->m_map.template addAttribute<T, ORBIT>(dname.str()) ;
-			}
-		}
-	}
-
-	virtual ~Approximator()
-	{
-		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-		{
-			this->m_map.template removeAttribute(m_approx[i]) ;
-			if(m_predictor)
-				this->m_map.template removeAttribute(m_detail[i]) ;
-		}
-	}
-
-	const std::string& getApproximatedAttributeName(unsigned int index = 0) const
-	{
-		return m_attrV[index]->name() ;
-	}
-
-//	std::vector<std::string> getApproximatedAttributeNames() const
-//	{
-//		std::vector<std::string> names ;
-//		names.resize(m_attrV.size()) ;
-//		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-//			names[i] = m_attrV[i]->name() ;
-//
-//		return names ;
-//	}
-
-	unsigned int getNbApproximated() const
-	{
-		return m_attrV.size() ;
-	}
-
-	void saveApprox(Dart d)
-	{
-		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-			m_app[i] = m_approx[i][d] ;
-	}
-
-	void affectApprox(Dart d)
-	{
-		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-			m_attrV[i]->operator[](d) = m_app[i] ;
-	}
-
-	const T& getApprox(Dart d, unsigned int index = 0) const
-	{
-		return m_approx[index][d] ;
-	}
-
-	const VertexAttribute<T>& getAttr(unsigned int index = 0) const
-	{
-		return *(m_attrV[index]) ;
-	}
-
-	std::vector<T> getAllApprox(Dart d) const
-	{
-		std::vector<T> res ;
-		res.resize(m_attrV.size()) ;
-		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-			res[i] = m_approx[i][d] ;
-
-		return res ;
-	}
-
-	const Predictor<PFP, T>* getPredictor() const
-	{
-		return m_predictor ;
-	}
-
-	const T& getDetail(Dart d, unsigned int index = 0) const
-	{
-		assert(m_predictor || !"Trying to get detail on a non-predictive scheme") ;
-		return m_detail[index][d] ;
-	}
-
-	std::vector<T> getAllDetail(Dart d) const
-	{
-		assert(m_predictor || !"Trying to get detail on a non-predictive scheme") ;
-
-		std::vector<T> res ;
-		res.resize(m_attrV.size()) ;
-		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-			res[i] = m_detail[i][d] ;
-		return res ;
-	}
-
-	void setDetail(Dart d, unsigned int index, T& val)
-	{
-		assert(m_predictor || !"Trying to set detail on a non-predictive scheme") ;
-		m_detail[index][d] = val ;
-	}
-
-	void setDetail(Dart d, std::vector<T>& val)
-	{
-		assert(m_predictor || !"Trying to set detail on a non-predictive scheme") ;
-
-		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-			m_detail[index][d] = val[i] ;
-	}
-
-
-//	// TODO works only for vector types !!
-//	REAL detailMagnitude(Dart d)
-//	{
-//		assert(m_predictor || !"Trying to get detail magnitude on a non-predictive scheme") ;
-//		return m_detail[d].norm2() ;
-//	}
-
-	void addDetail(Dart d, double amount, bool sign, typename PFP::MATRIX33* detailTransform)
-	{
-		assert(m_predictor || !"Trying to add detail on a non-predictive scheme") ;
-
-		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
-		{
-			T det = m_detail[i][d] ;
-			if(detailTransform)
-				det = (*detailTransform) * det ;
-			det *= amount ;
-			if(!sign)
-				det *= REAL(-1) ;
-			m_attrV[i]->operator[](d) += det ;
-		}
-	}
+	Approximator(MAP& m, std::vector<VertexAttribute<T>* > va, Predictor<PFP, T> * predictor) ;
+	virtual ~Approximator() ;
+	const std::string& getApproximatedAttributeName(unsigned int index = 0) const ;
+	unsigned int getNbApproximated() const ;
+	void saveApprox(Dart d) ;
+	void affectApprox(Dart d) ;
+	const T& getApprox(Dart d, unsigned int index = 0) const ;
+	const VertexAttribute<T>& getAttr(unsigned int index = 0) const ;
+	VertexAttribute<T>& getAttr(unsigned int index = 0) ;
+	std::vector<T> getAllApprox(Dart d) const ;
+	const Predictor<PFP, T>* getPredictor() const ;
+	const T& getDetail(Dart d, unsigned int index = 0) const ;
+	std::vector<T> getAllDetail(Dart d) const ;
+	void setDetail(Dart d, unsigned int index, T& val) ;
+	void setDetail(Dart d, std::vector<T>& val) ;
+	// REAL detailMagnitude(Dart d) ; // TODO works only for vector types !!
+	void addDetail(Dart d, double amount, bool sign, typename PFP::MATRIX33* detailTransform) ;
 } ;
 
-} //namespace Decimation
+} // namespace Decimation
+
+} // namespace surface
 
-} // surface
+} // namespace Algo
 
-} //namespace Algo
+} // namespace CGoGN
 
-} //namespace CGoGN
+#include "Algo/Decimation/approximator.hpp"
 
 #endif

include/Algo/Decimation/approximator.hpp

+/*******************************************************************************
+* CGoGN: Combinatorial and Geometric modeling with Generic N-dimensional Maps  *
+* version 0.1                                                                  *
+* Copyright (C) 2009-2013, IGG Team, ICube, University of Strasbourg           *
+*                                                                              *
+* This library is free software; you can redistribute it and/or modify it      *
+* under the terms of the GNU Lesser General Public License as published by the *
+* Free Software Foundation; either version 2.1 of the License, or (at your     *
+* option) any later version.                                                   *
+*                                                                              *
+* This library 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 Lesser General Public License  *
+* for more details.                                                            *
+*                                                                              *
+* You should have received a copy of the GNU Lesser General Public License     *
+* along with this library; if not, write to the Free Software Foundation,      *
+* Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA.           *
+*                                                                              *
+* Web site: http://cgogn.unistra.fr/                                           *
+* Contact information: cgogn@unistra.fr                                        *
+*                                                                              *
+*******************************************************************************/
+
+namespace CGoGN
+{
+
+namespace Algo
+{
+
+namespace Surface
+{
+
+namespace Decimation
+{
+
+template <typename PFP, typename T, unsigned int ORBIT>
+Approximator<PFP,T,ORBIT>::Approximator(MAP& m, std::vector<VertexAttribute<T>* > va, Predictor<PFP, T> * predictor) :
+	ApproximatorGen<PFP>(m), m_predictor(predictor), m_attrV(va)
+{
+	const unsigned int& size = m_attrV.size() ;
+	assert(size > 0 || !"Approximator: no attributes provided") ;
+
+	m_approx.resize(size) ;
+	m_detail.resize(size) ;
+	m_app.resize(size) ;
+
+	for (unsigned int i = 0 ; i < size ; ++i)
+	{
+		if (!m_attrV[i]->isValid())
+			std::cerr << "Approximator Warning: attribute number " << i << " is not valid" << std::endl ;
+
+		std::stringstream aname ;
+		aname << "approx_" << m_attrV[i]->name() ;
+		m_approx[i] = this->m_map.template addAttribute<T, ORBIT>(aname.str()) ;
+
+		if(m_predictor)	// if predictors are associated to the approximator
+		{				// create attributes to store the details needed for reconstruction
+			std::stringstream dname ;
+			dname << "detail_" << m_attrV[i]->name() ;
+			m_detail[i] = this->m_map.template addAttribute<T, ORBIT>(dname.str()) ;
+		}
+	}
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+Approximator<PFP,T,ORBIT>::~Approximator()
+{
+	std::cout << "Approximator<PFP,T,ORBIT>::~Approximator()" << std::endl ;
+	for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+	{
+		this->m_map.template removeAttribute(m_approx[i]) ;
+		if(m_predictor)
+			this->m_map.template removeAttribute(m_detail[i]) ;
+	}
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+const std::string&
+Approximator<PFP,T,ORBIT>::getApproximatedAttributeName(unsigned int index) const
+{
+	return m_attrV[index]->name() ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+unsigned int
+Approximator<PFP,T,ORBIT>::getNbApproximated() const
+{
+	return m_attrV.size() ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+void
+Approximator<PFP,T,ORBIT>::saveApprox(Dart d)
+{
+	for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+	{
+		m_app[i] = m_approx[i][d] ;
+	}
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+void
+Approximator<PFP,T,ORBIT>::affectApprox(Dart d)
+{
+	for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+	{
+		m_attrV[i]->operator[](d) = m_app[i] ;
+	}
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+const T&
+Approximator<PFP,T,ORBIT>::getApprox(Dart d, unsigned int index) const
+{
+	return m_approx[index][d] ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+const VertexAttribute<T>&
+Approximator<PFP,T,ORBIT>::getAttr(unsigned int index) const
+{
+	return *(m_attrV[index]) ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+VertexAttribute<T>&
+Approximator<PFP,T,ORBIT>::getAttr(unsigned int index)
+{
+	return *(m_attrV[index]) ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+std::vector<T>
+Approximator<PFP,T,ORBIT>::getAllApprox(Dart d) const
+{
+	std::vector<T> res ;
+	res.resize(m_attrV.size()) ;
+	for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+		res[i] = m_approx[i][d] ;
+
+	return res ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+const Predictor<PFP, T>*
+Approximator<PFP,T,ORBIT>::getPredictor() const
+{
+	return m_predictor ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+const T&
+Approximator<PFP,T,ORBIT>::getDetail(Dart d, unsigned int index) const
+{
+	assert(m_predictor || !"Trying to get detail on a non-predictive scheme") ;
+	return m_detail[index][d] ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+std::vector<T>
+Approximator<PFP,T,ORBIT>::getAllDetail(Dart d) const
+{
+	assert(m_predictor || !"Trying to get detail on a non-predictive scheme") ;
+
+	std::vector<T> res ;
+	res.resize(m_attrV.size()) ;
+	for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+		res[i] = m_detail[i][d] ;
+	return res ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+void
+Approximator<PFP,T,ORBIT>::setDetail(Dart d, unsigned int index, T& val)
+{
+	assert(m_predictor || !"Trying to set detail on a non-predictive scheme") ;
+	m_detail[index][d] = val ;
+}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+void
+Approximator<PFP,T,ORBIT>::setDetail(Dart d, std::vector<T>& val)
+{
+	assert(m_predictor || !"Trying to set detail on a non-predictive scheme") ;
+
+	for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+		m_detail[index][d] = val[i] ;
+}
+
+
+//	// TODO works only for vector types !!
+//	REAL detailMagnitude(Dart d)
+//	{
+//		assert(m_predictor || !"Trying to get detail magnitude on a non-predictive scheme") ;
+//		return m_detail[d].norm2() ;
+//	}
+
+template <typename PFP, typename T, unsigned int ORBIT>
+void
+Approximator<PFP,T,ORBIT>::addDetail(Dart d, double amount, bool sign, typename PFP::MATRIX33* detailTransform)
+{
+	assert(m_predictor || !"Trying to add detail on a non-predictive scheme") ;
+
+	for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+	{
+		T det = m_detail[i][d] ;
+		if(detailTransform)
+			det = (*detailTransform) * det ;
+		det *= amount ;
+		if(!sign)
+			det *= REAL(-1) ;
+		m_attrV[i]->operator[](d) += det ;
+	}
+}
+
+} //namespace Decimation
+
+} // namespace surface
+
+} //namespace Algo
+
+} //namespace CGoGN

include/Algo/Decimation/colorPerVertexApproximator.h

 /*******************************************************************************
 * CGoGN: Combinatorial and Geometric modeling with Generic N-dimensional Maps  *
 * version 0.1                                                                  *
-* Copyright (C) 2009-2012, IGG Team, LSIIT, University of Strasbourg           *
+* Copyright (C) 2009-2013, IGG Team, ICube, University of Strasbourg           *
 *                                                                              *
 * This library is free software; you can redistribute it and/or modify it      *
 * under the terms of the GNU Lesser General Public License as published by the *
@@ -121,48 +121,46 @@ public:
 	void approximate(Dart d) ;
 } ;
 
-/*
 template <typename PFP>
-class Approximator_ColorQEMextHalfCollapse : public Approximator<PFP, typename PFP::VEC3>
+class Approximator_GeomColOpt : public Approximator<PFP, typename PFP::VEC3, EDGE>
 {
 public:
 	typedef typename PFP::MAP MAP ;
 	typedef typename PFP::REAL REAL ;
 	typedef typename PFP::VEC3 VEC3 ;
-	typedef Geom::Vector<6,REAL> VEC6 ;
 
 protected:
-	VertexAttribute<Utils::QuadricNd<REAL,6> > m_quadric ;
+	VertexAttribute<Utils::Quadric<REAL> > m_quadric ;
 	VertexAttribute<VEC3> *m_position ;
 	VertexAttribute<VEC3> *m_color ;
 
 public:
-	Approximator_ColorQEMextHalfCollapse(MAP& m, std::vector<VertexAttribute<VEC3>* >& attr, Predictor<PFP, VEC3>* pred = NULL) :
-		Approximator<PFP, VEC3>(m, attr, pred)
+	Approximator_GeomColOpt(MAP& m, std::vector<VertexAttribute<VEC3>* >& attr, Predictor<PFP, VEC3>* pred = NULL) :
+		Approximator<PFP, VEC3, EDGE>(m, attr, pred)
 	{
-		assert(attr.size() > 1 || !"Approximator_ColorQEMext_HalfCollapse: there are not sufficient attributes provided") ;
+		assert(attr.size() > 1 || !"Approximator_GeomColOpt: there are not sufficient attributes provided") ;
 
 		m_position = this->m_attrV[0] ;
 		m_color = this->m_attrV[1] ;
 	}
 
-	~Approximator_ColorQEMextHalfCollapse()
+	~Approximator_GeomColOpt()
 	{}
 
 	ApproximatorType getType() const
 	{
-		return A_ColorQEMextHalfCollapse ;
+		return A_GeomColorOpt ;
 	}
 
 	bool init() ;
 
 	void approximate(Dart d) ;
 } ;
-*/
+
 
 } //namespace Decimation
 
-}
+} // namespace Surface
 
 } //namespace Algo
 

include/Algo/Decimation/colorPerVertexApproximator.hpp

 /*******************************************************************************
 * CGoGN: Combinatorial and Geometric modeling with Generic N-dimensional Maps  *
 * version 0.1                                                                  *
-* Copyright (C) 2009-2012, IGG Team, LSIIT, University of Strasbourg           *
+* Copyright (C) 2009-2013, IGG Team, ICube, University of Strasbourg           *
 *                                                                              *
 * This library is free software; you can redistribute it and/or modify it      *
 * under the terms of the GNU Lesser General Public License as published by the *
@@ -165,6 +165,102 @@ void Approximator_ColorQEMext<PFP>::approximate(Dart d)
 	}
 }
 
+/************************************************************************************
+ *                    GEOM + COLOR OPTIMIZED ERROR METRIC                           *
+ ************************************************************************************/
+template <typename PFP>
+bool Approximator_GeomColOpt<PFP>::init()
+{
+	m_quadric = this->m_map.template getAttribute<Utils::Quadric<REAL>, VERTEX>("QEMquadric") ;
+	// Does not require to be valid (if it is not, altenatives will be used).
+
+	if(this->m_predictor)
+	{
+		return false ;
+	}
+
+	return m_position->isValid() && m_color->isValid() ;
+}
+
+template <typename PFP>
+void Approximator_GeomColOpt<PFP>::approximate(Dart d)
+{
+	MAP& m = this->m_map ;
+
+	// get some darts
+	Dart dd = m.phi2(d) ;
+
+	// POSITION
+	Utils::Quadric<REAL> q1, q2 ;
+	if(!m_quadric.isValid()) // if the selector is not QEM, compute local error quadrics
+	{
+		// compute the error quadric associated to v1
+		Dart it = d ;
+		do
+		{
+			Utils::Quadric<REAL> q(this->m_attrV[0]->operator[](it), this->m_attrV[0]->operator[](m.phi1(it)), this->m_attrV[0]->operator[](m.phi_1(it))) ;
+			q1 += q ;
+			it = m.phi2_1(it) ;
+		} while(it != d) ;
+
+		// compute the error quadric associated to v2
+		it = dd ;
+		do
+		{
+			Utils::Quadric<REAL> q(this->m_attrV[0]->operator[](it), this->m_attrV[0]->operator[](m.phi1(it)), this->m_attrV[0]->operator[](m.phi_1(it))) ;
+			q2 += q ;
+			it = m.phi2_1(it) ;
+		} while(it != dd) ;
+	}
+	else // if the selector is QEM, use the error quadrics computed by the selector
+	{
+		q1 = m_quadric[d] ;
+		q2 = m_quadric[dd] ;
+	}
+
+	Utils::Quadric<REAL> quad ;
+	quad += q1 ;	// compute the sum of the
+	quad += q2 ;	// two vertices quadrics
+
+	VEC3 res ;
+	bool opt = quad.findOptimizedPos(res) ;	// try to compute an optimized position for the contraction of this edge
+
+	const VEC3& p0 = this->m_attrV[0]->operator[](d) ;    // let the new vertex lie
+	const VEC3& p1 = this->m_attrV[0]->operator[](dd) ;   // on either one of the two endpoints
+
+	if(false && !opt)
+	{
+		VEC3 p12 = (p0 + p1) / 2.0f ;   // or the middle of the edge
+		REAL e1 = quad(p0) ;
+		REAL e2 = quad(p1) ;
+		REAL e12 = quad(p12) ;
+		REAL minerr = std::min(std::min(e1, e2), e12) ; // consider only the one for
+		if(minerr == e12)		this->m_approx[0][d] = p12 ;             // which the error is minimal
+		else if(minerr == e1)	this->m_approx[0][d] = p0 ;
+		else					this->m_approx[0][d] = p1 ;
+	}
+	// copy res into m_approx
+	else
+	{
+		this->m_approx[0][d] = res ;
+	}
+	const VEC3& p = this->m_approx[0][d] ;
+
+	// COLOR
+	const VEC3& c1 = this->m_attrV[1]->operator[](d) ;    // let the new vertex lie
+	const VEC3& c2 = this->m_attrV[1]->operator[](dd) ;   // on either one of the two endpoints
+
+	VEC3 e = p1 - p0 ;
+	VEC3 e1 = p - p0 ;
+	const REAL normE1 = e1.normalize() ;
+	const REAL normE = e.normalize() ;
+	REAL ratio = (e * e1)*normE1/normE ;
+	ratio = std::max(REAL(0),std::min(REAL(1),ratio)) ;
+
+	this->m_approx[1][d] = ratio*c1 + (1-ratio)*c2 ;
+}
+
+
 } //namespace Decimation
 
 }

include/Algo/Decimation/decimation.h

 /*******************************************************************************
 * CGoGN: Combinatorial and Geometric modeling with Generic N-dimensional Maps  *
 * version 0.1                                                                  *
-* Copyright (C) 2009-2012, IGG Team, LSIIT, University of Strasbourg           *
+* Copyright (C) 2009-2013, IGG Team, ICube, University of Strasbourg           *
 *                                                                              *
 * This library is free software; you can redistribute it and/or modify it      *
 * under the terms of the GNU Lesser General Public License as published by the *
@@ -29,7 +29,6 @@
 #include "Algo/Decimation/halfEdgeSelector.h"
 #include "Algo/Decimation/geometryApproximator.h"
 #include "Algo/Decimation/colorPerVertexApproximator.h"