Developer Documentation
meshDualT.hh
1 /* ========================================================================= *
2  * *
3  * OpenMesh *
4  * Copyright (c) 2001-2015, RWTH-Aachen University *
5  * Department of Computer Graphics and Multimedia *
6  * All rights reserved. *
7  * www.openmesh.org *
8  * *
9  *---------------------------------------------------------------------------*
10  * This file is part of OpenMesh. *
11  *---------------------------------------------------------------------------*
12  * *
13  * Redistribution and use in source and binary forms, with or without *
14  * modification, are permitted provided that the following conditions *
15  * are met: *
16  * *
17  * 1. Redistributions of source code must retain the above copyright notice, *
18  * this list of conditions and the following disclaimer. *
19  * *
20  * 2. Redistributions in binary form must reproduce the above copyright *
21  * notice, this list of conditions and the following disclaimer in the *
22  * documentation and/or other materials provided with the distribution. *
23  * *
24  * 3. Neither the name of the copyright holder nor the names of its *
25  * contributors may be used to endorse or promote products derived from *
26  * this software without specific prior written permission. *
27  * *
28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS *
29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED *
30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *
31  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER *
32  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, *
33  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, *
34  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR *
35  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF *
36  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING *
37  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS *
38  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *
39  * *
40  * ========================================================================= */
41 
42 /*===========================================================================*\
43  * *
44  * $Revision$ *
45  * $Date$ *
46  * *
47 \*===========================================================================*/
48 
49 /*
50  Compute the dual of a mesh:
51  - each face of the original mesh is replaced by a vertex at the center of gravity of the vertices of the face
52  - each vertex of the original mesh is replaced by a face containing the dual vertices of its primal adjacent faces
53 
54  Changelog:
55  - 29 mar 2010: initial work
56 
57  Programmer:
58  Clement Courbet - clement.courbet@ecp.fr
59 
60  (c) Clement Courbet 2010
61 */
62 
63 #ifndef OPENMESH_MESH_DUAL_H
64 #define OPENMESH_MESH_DUAL_H
65 
66 //== INCLUDES =================================================================
67 
68 // -------------------- STL
69 #include <vector>
70 #if defined(OM_CC_MIPS)
71 # include <math.h>
72 #else
73 # include <cmath>
74 #endif
75 
76 #include <OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
77 #include <OpenMesh/Core/Utils/Property.hh>
78 
79 //== FORWARDDECLARATIONS ======================================================
80 
81 //== NAMESPACES ===============================================================
82 
83 
84 namespace OpenMesh {
85 namespace Util {
86 
87 //== Function DEFINITION =========================================================
88 
94 template <typename MeshTraits>
95 PolyMesh_ArrayKernelT<MeshTraits>* MeshDual (PolyMesh_ArrayKernelT<MeshTraits> &primal)
96 {
97  PolyMesh_ArrayKernelT<MeshTraits>* dual = new PolyMesh_ArrayKernelT<MeshTraits>();
98 
99  //we will need to reference which vertex in the dual is attached to each face in the primal
100  //and which face of the dual is attached to each vertex in the primal.
101 
102  FPropHandleT< typename PolyMesh_ArrayKernelT<MeshTraits>::VertexHandle > primalToDual;
103  primal.add_property(primalToDual);
104 
105  //for each face in the primal mesh, add a vertex at the center of gravity of the face
106  for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstFaceIter fit=primal.faces_begin(); fit!=primal.faces_end(); ++fit)
107  {
108  typename PolyMesh_ArrayKernelT<MeshTraits>::Point centerPoint(0,0,0);
109  typename PolyMesh_ArrayKernelT<MeshTraits>::Scalar degree= 0.0;
110  for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstFaceVertexIter vit=primal.cfv_iter(*fit); vit.is_valid(); ++vit, ++degree)
111  centerPoint += primal.point(*vit);
112  assert(degree!=0);
113  centerPoint /= degree;
114  primal.property(primalToDual, *fit) = dual->add_vertex(centerPoint);
115  }
116 
117  //for each vertex in the primal, add a face in the dual
118  std::vector< typename PolyMesh_ArrayKernelT<MeshTraits>::VertexHandle > face_vhandles;
119  for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstVertexIter vit=primal.vertices_begin(); vit!=primal.vertices_end(); ++vit)
120  {
121  if(!primal.is_boundary(*vit))
122  {
123  face_vhandles.clear();
124  for(typename PolyMesh_ArrayKernelT<MeshTraits>::ConstVertexFaceIter fit=primal.cvf_iter(*vit); fit.is_valid(); ++fit)
125  face_vhandles.push_back(primal.property(primalToDual, *fit));
126  dual->add_face(face_vhandles);
127  }
128  }
129 
130  primal.remove_property(primalToDual);
131 
132  return dual;
133 
134 }
135 
136 //=============================================================================
137 } // namespace Util
138 } // namespace OpenMesh
139 //=============================================================================
140 
141 //=============================================================================
142 #endif // OPENMESH_MESH_DUAL_H defined
143 //=============================================================================
144 
145 
Kernel::ConstFaceVertexIter ConstFaceVertexIter
Circulator.
Definition: PolyMeshT.hh:180
Kernel::ConstVertexFaceIter ConstVertexFaceIter
Circulator.
Definition: PolyMeshT.hh:179
Kernel::Point Point
Coordinate type.
Definition: PolyMeshT.hh:115
Kernel::Scalar Scalar
Scalar type.
Definition: PolyMeshT.hh:113