IHM -> test arete simplifiable

include/Algo/ImplicitHierarchicalMesh/ihm.h

@@ -174,6 +174,14 @@ public:
 	 */
 	bool edgeIsSubdivided(Dart d) ;
 
+	/**
+	 * Return true if the edge of d in the current level map
+	 * is subdivided to the next level,
+	 * none of its resulting edges is in turn subdivided to the next level
+	 * and the middle vertex is of degree 2
+	 */
+	bool edgeCanBeCoarsened(Dart d) ;
+
 	/**
 	 * Return true if the face of d in the current level map
 	 * has already been subdivided to the next level
@@ -183,7 +191,7 @@ public:
 	/**
 	 * Return true if the face of d in the current level map
 	 * is subdivided to the next level
-	 * and none of these resulting faces is in turn subdivided to the next level
+	 * and none of its resulting faces is in turn subdivided to the next level
 	 */
 	bool faceIsSubdividedOnce(Dart d) ;
 } ;

include/Algo/ImplicitHierarchicalMesh/subdivision.hpp

@@ -144,6 +144,8 @@ template <typename PFP>
 void coarsenEdge(typename PFP::MAP& map, Dart d, typename PFP::TVEC3& position)
 {
 	assert(map.getDartLevel(d) <= map.getCurrentLevel() || !"Access to a dart introduced after current level") ;
+	assert(map.edgeCanBeCoarsened(d) || !"Trying to coarsen an edge that can not be coarsened") ;
+
 }
 
 template <typename PFP>

src/Algo/ImplicitHierarchicalMesh/ihm.cpp

@@ -131,18 +131,10 @@ Dart ImplicitHierarchicalMap::faceOldestDart(Dart d)
 bool ImplicitHierarchicalMap::edgeIsSubdivided(Dart d)
 {
 	assert(m_dartLevel[d] <= m_curLevel || !"Access to a dart introduced after current level") ;
-
 //	Dart d2 = phi2(d) ;
-//	++m_curLevel ;
-//	Dart d2_l = phi2(d) ;
-//	--m_curLevel ;
-//	if(d2 != d2_l)
-//		return true ;
-//	else
-//		return false ;
-
 	Dart d1 = phi1(d) ;
 	++m_curLevel ;
+//	Dart d2_l = phi2(d) ;
 	Dart d1_l = phi1(d) ;
 	--m_curLevel ;
 	if(d1 != d1_l)
@@ -151,6 +143,28 @@ bool ImplicitHierarchicalMap::edgeIsSubdivided(Dart d)
 		return false ;
 }
 
+bool ImplicitHierarchicalMap::edgeCanBeCoarsened(Dart d)
+{
+	assert(m_dartLevel[d] <= m_curLevel || !"Access to a dart introduced after current level") ;
+	bool subd = false ;
+	bool subdOnce = true ;
+	bool degree2 = false ;
+	if(edgeIsSubdivided(d))
+	{
+		subd = true ;
+		Dart d2 = phi2(d) ;
+		++m_curLevel ;
+		if(vertexDegree(phi1(d)) == 2)
+		{
+			degree2 = true ;
+			if(edgeIsSubdivided(d) || edgeIsSubdivided(d2))
+				subdOnce = false ;
+		}
+		--m_curLevel ;
+	}
+	return subd && degree2 && subdOnce ;
+}
+
 bool ImplicitHierarchicalMap::faceIsSubdivided(Dart d)
 {
 	assert(m_dartLevel[d] <= m_curLevel || !"Access to a dart introduced after current level") ;