Added Mesh dualizer tool (Thanks to Clement Courbet for providing the code)

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@316 fdac6126-5c0c-442c-9429-916003d36597

src/OpenMesh/Tools/Dualizer/meshDualT.hh

@@ -0,0 +1,138 @@
+/*===========================================================================*\
+ *                                                                           *
+ *                               OpenMesh                                    *
+ *      Copyright (C) 2001-2009 by Computer Graphics Group, RWTH Aachen      *
+ *                           www.openmesh.org                                *
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+ *  This file is part of OpenMesh.                                           *
+ *                                                                           *
+ *  OpenMesh is free software: you can redistribute it and/or modify         *
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+ *  If other files instantiate templates or use macros                       *
+ *  or inline functions from this file, or you compile this file and         *
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+ *  not by itself cause the resulting executable to be covered by the        *
+ *  GNU Lesser General Public License. This exception does not however       *
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+\*===========================================================================*/
+
+/*===========================================================================*\
+ *                                                                           *
+ *   $Revision$                                                         *
+ *   $Date$                   *
+ *                                                                           *
+\*===========================================================================*/
+
+/*
+  Compute the dual of a mesh:
+  - each face of the original mesh is replaced by a vertex at the center of gravity of the vertices of the face
+  - each vertex of the original mesh is replaced by a face containing the dual vertices of its primal adjacent faces
+
+  Changelog:
+    - 29 mar 2010: initial work
+
+  Programmer: 
+    Clement Courbet - clement.courbet@ecp.fr
+
+  (c) Clement Courbet 2010
+*/
+
+#ifndef OPENMESH_MESH_DUAL_H
+#define OPENMESH_MESH_DUAL_H
+
+//== INCLUDES =================================================================
+
+// -------------------- STL
+#include <vector>
+#if defined(OM_CC_MIPS)
+#  include <math.h>
+#else
+#  include <cmath>
+#endif
+
+#include <OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
+#include <OpenMesh/Core/Utils/Property.hh>
+
+//== FORWARDDECLARATIONS ======================================================
+
+//== NAMESPACES ===============================================================
+
+
+namespace OpenMesh   { 
+namespace Util { 
+
+//== Function DEFINITION =========================================================
+
+/** \brief create a dual mesh
+*
+* This function takes a mesh and computes the dual mesh of it. Each face of the original mesh is replaced by a vertex at the center of gravity of the vertices of the face.
+* Each vertex of the original mesh is replaced by a face containing the dual vertices of its primal adjacent faces.
+*/
+template <typename MeshTraits>
+PolyMesh_ArrayKernelT<MeshTraits>* MeshDual (PolyMesh_ArrayKernelT<MeshTraits> &primal)
+{
+  PolyMesh_ArrayKernelT<MeshTraits>* dual = new PolyMesh_ArrayKernelT<MeshTraits>();
+
+  //we will need to reference which vertex in the dual is attached to each face in the primal
+  //and which face of the dual is attached to each vertex in the primal.
+
+  FPropHandleT< typename PolyMesh_ArrayKernelT<MeshTraits>::VertexHandle > primalToDual;
+  primal.add_property(primalToDual);
+
+  //for each face in the primal mesh, add a vertex at the center of gravity of the face
+  for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstFaceIter fit=primal.faces_begin(); fit!=primal.faces_end(); ++fit)
+  {
+      typename PolyMesh_ArrayKernelT<MeshTraits>::Point centerPoint(0,0,0);
+      unsigned int degree= 0;
+      for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstFaceVertexIter vit=primal.cfv_iter(fit); vit; ++vit, ++degree)
+	  centerPoint += primal.point(vit.handle());
+      assert(degree!=0);
+      centerPoint /= degree;
+      primal.property(primalToDual, fit) = dual->add_vertex(centerPoint);
+  }
+
+  //for each vertex in the primal, add a face in the dual
+  std::vector< typename PolyMesh_ArrayKernelT<MeshTraits>::VertexHandle >  face_vhandles;
+  for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstVertexIter vit=primal.vertices_begin(); vit!=primal.vertices_end(); ++vit)
+  {
+      if(!primal.is_boundary(vit.handle()))
+      {
+	  face_vhandles.clear();
+	  for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstVertexFaceIter fit=primal.cvf_iter(vit); fit; ++fit)
+	      face_vhandles.push_back(primal.property(primalToDual, fit));
+	  dual->add_face(face_vhandles);
+      }
+  }
+
+  primal.remove_property(primalToDual);
+
+  return dual;
+
+};
+
+//=============================================================================
+} // namespace Util
+} // namespace OpenMesh
+//=============================================================================
+
+//=============================================================================
+#endif // OPENMESH_MESH_DUAL_H defined
+//=============================================================================
+
+