From 79d815d8bad1568455f4f651871b30b982c8f0c5 Mon Sep 17 00:00:00 2001
From: Laurent Rineau <Laurent.Rineau__CGAL@normalesup.org>
Date: Thu, 27 Aug 2009 16:05:28 +0000
Subject: [PATCH] Add an export function from c3t3 to vtk unstructured grid

---
 .../IO/Complex_3_in_triangulation_3_to_vtk.h  | 107 ++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 Mesh_3/include/CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h

diff --git a/Mesh_3/include/CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h b/Mesh_3/include/CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h
new file mode 100644
index 00000000000..bd7257dc4aa
--- /dev/null
+++ b/Mesh_3/include/CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h
@@ -0,0 +1,107 @@
+// Copyright (c) 2008-2009  GeometryFactory (France).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org); you may redistribute it under
+// the terms of the Q Public License version 1.0.
+// See the file LICENSE.QPL distributed with CGAL.
+//
+// Licensees holding a valid commercial license may use this file in
+// accordance with the commercial license agreement provided with the software.
+//
+// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// $URL$
+// $Id$
+//
+//
+// Author(s)     : Laurent Rineau
+
+#ifndef CGAL_COMPLEX_3_IN_TRIANGULATION_3_TO_VTK
+#define CGAL_COMPLEX_3_IN_TRIANGULATION_3_TO_VTK
+
+#include <map>
+
+#include <vtkPoints.h>
+#include <vtkUnstructuredGrid.h>
+#include <vtkCellArray.h>
+#include <vtkType.h>
+
+namespace CGAL {
+
+template <typename C3T3>
+vtkUnstructuredGrid* 
+output_c3t3_to_vtk_unstructured_grid(const C3T3& c3t3, 
+                                     vtkUnstructuredGrid* grid = 0)
+{
+  typedef typename C3T3::Triangulation Triangulation;
+  typedef typename Triangulation::Vertex_handle Vertex_handle;
+
+  const Triangulation& tr = c3t3.triangulation();
+
+  vtkPoints* const vtk_points = vtkPoints::New();
+  vtkCellArray* const vtk_facets = vtkCellArray::New();
+  vtkCellArray* const vtk_cells = vtkCellArray::New();
+
+  vtk_points->Allocate(c3t3.triangulation().number_of_vertices());
+  vtk_facets->Allocate(c3t3.number_of_facets());
+  vtk_cells->Allocate(c3t3.number_of_cells());
+
+  std::map<Vertex_handle, vtkIdType> V;
+  vtkIdType inum = 0;
+
+  for(typename Triangulation::Finite_vertices_iterator 
+        vit = tr.finite_vertices_begin(),
+        end = tr.finite_vertices_end();
+      vit != end;
+      ++vit)
+  {
+    typedef typename Triangulation::Point Point;
+    const Point& p = vit->point();
+    vtk_points->InsertNextPoint(CGAL::to_double(p.x()),
+                                CGAL::to_double(p.y()),
+                                CGAL::to_double(p.z()));
+    V[vit] = inum++;
+  }
+  for(typename C3T3::Facet_iterator 
+        fit = c3t3.facets_begin(),
+        end = c3t3.facets_end();
+      fit != end; ++fit) 
+  {
+    vtkIdType cell[3];
+    int j=0;
+    for (int i = 0; i < 4; ++i)
+      if (i != fit->second)
+        cell[j++] =  V[(*fit).first->vertex(i)];
+    CGAL_assertion(j==3);
+    vtk_facets->InsertNextCell(3, cell);
+  }
+
+  for(typename C3T3::Cell_iterator 
+        cit = c3t3.cells_begin(),
+        end = c3t3.cells_end();
+      cit != end; ++cit) 
+  {
+    vtkIdType cell[4];
+    for (int i = 0; i < 4; ++i)
+      cell[i] =  V[cit->vertex(i)];
+    vtk_facets->InsertNextCell(4, cell);
+  }
+
+  if(!grid) {
+    grid = vtkUnstructuredGrid::New();
+  }
+
+  grid->SetPoints(vtk_points);
+  vtk_points->Delete();
+
+  grid->SetCells(VTK_TRIANGLE, vtk_facets);
+  grid->SetCells(VTK_TETRA, vtk_cells);
+  vtk_facets->Delete();
+  vtk_cells->Delete();
+  return grid;
+}
+
+} // end namespace CGAL
+
+#endif // CGAL_COMPLEX_3_IN_TRIANGULATION_3_TO_VTK