implemented Tri::reviseElement()

MeshLib/Elements/Tri.cpp

@@ -11,6 +11,7 @@
  */
 
 #include "Tri.h"
+#include "Edge.h"
 #include "Node.h"
 
 #include "MathTools.h"
@@ -76,5 +77,19 @@ double Tri::computeArea()
 	return MathLib::calcTriangleArea(_nodes[0]->getCoords(), _nodes[1]->getCoords(), _nodes[2]->getCoords());
 }
 
+Element* Tri::reviseElement() const
+{
+	// try to create an edge
+	if (_nodes[0] == _nodes[1] || _nodes[1] == _nodes[2]) {
+		return new Edge(_nodes[0], _nodes[2], _value);
+	}
+
+	if (_nodes[0] == _nodes[2]) {
+		return new Edge(_nodes[0], _nodes[1], _value);
+	}
+
+	return NULL;
+}
+
 }
 

MeshLib/Elements/Tri.h

@@ -18,18 +18,19 @@
 namespace MeshLib {
 
 /**
- * A 2d Triangle Element.
+ * This class represents a 2d triangle element. The following sketch shows the node and edge numbering.
+ * @anchor TriNodeAndEdgeNumbering
  * @code
  *
- *  Tri:    2
+ *          2
  *          o
  *         / \
  *        /   \
- *       /     \
+ *      2/     \1
  *      /       \
  *     /         \
- *    o-----------o
- *    0           1
+ *    0-----------1
+ *          0
  *
  * @endcode
  */
@@ -69,6 +70,16 @@ public:
 	 */
 	virtual Element* clone() const;
 
+	/**
+	 * This method should be called after at least two nodes of the triangle
+	 * element are collapsed. As a consequence of the node collapsing an edge
+	 * of the triangle will be collapsed. If one of the edges is collapsed we
+	 * obtain an edge. In this case the method will create the appropriate
+	 * object of class Edge.
+	 * @return an Edge object or NULL
+	 */
+	virtual Element* reviseElement() const;
+
 protected:
 	/// Calculates the area of the triangle by returning half of the area of the corresponding parallelogram.
 	double computeArea();