Add CGAL::read_off() and CGAL::write_off() to OpenMesh

BGL/examples/BGL_OpenMesh/TriMesh.cpp

@@ -36,13 +36,13 @@ int main(int argc, char** argv )
   V.push_back(add_vertex(mesh));
   add_face(V.begin(), V.end(), mesh);
 
-  //  OpenMesh::IO::read_mesh(mesh, (argc>1)?argv[1]:"in.off");
+  CGAL::read_off(std::ifstream((argc>1)?argv[1]:"in.off"), mesh);
   
   BOOST_FOREACH(vertex_descriptor vd, vertices(mesh)){
     BOOST_FOREACH(halfedge_descriptor hd, CGAL::halfedges_around_target(vd,mesh)){
       if(! CGAL::is_border(edge(hd,mesh),mesh)){
         CGAL::Euler::flip_edge(hd,mesh);
-        OpenMesh::IO::write_mesh(mesh, (argc>2)?argv[2]:"out.off");
+        CGAL::write_off((argc>2)?argv[2]:"out.off", mesh);
         return 0;
       }
     }

BGL/include/CGAL/boost/graph/graph_traits_PolyMesh_ArrayKernelT.h

@@ -33,6 +33,7 @@
 #include <CGAL/boost/graph/iterator.h>
 #include <CGAL/Iterator_range.h>
 #include <CGAL/boost/graph/helpers.h>
+#include <CGAL/boost/graph/io.h>
 #include <CGAL/assertions.h>
 
 #include <OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
@@ -691,6 +692,20 @@ void clear(OpenMesh::PolyMesh_ArrayKernelT<K>& sm)
   CGAL_postcondition(num_faces(sm) == 0);
 }
 
+
+template<typename K>
+bool read_off(std::istream& is, OpenMesh::PolyMesh_ArrayKernelT<K>& sm)
+{
+  return OpenMesh::IO::read_mesh(sm, is, ".OFF");
+}
+
+
+template<typename K>
+bool write_off(std::ostream& os, OpenMesh::PolyMesh_ArrayKernelT<K>& sm)
+{
+  return OpenMesh::IO::write_mesh(sm, os, ".OFF");
+}
+
 }
 #ifndef CGAL_NO_DEPRECATED_CODE
 #include <CGAL/boost/graph/backward_compatibility_functions.h>

BGL/include/CGAL/boost/graph/graph_traits_TriMesh_ArrayKernelT.h

@@ -31,6 +31,7 @@
 #include <CGAL/boost/graph/iterator.h>
 #include <CGAL/Iterator_range.h>
 #include <CGAL/boost/graph/helpers.h>
+#include <CGAL/boost/graph/io.h>
 #include <CGAL/assertions.h>
 
 #include <OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh>
@@ -610,7 +611,40 @@ bool is_valid(OpenMesh::TriMesh_ArrayKernelT<K>& sm, bool /* verbose */ = false)
 
 } // namespace OpenMesh
 
+namespace CGAL {
 
+// Overload CGAL::clear function. TriMesh_ArrayKernel behaves
+// differently from other meshes. Calling clear does not affect the
+// number of vertices, edges, or faces in the mesh. To get actual
+// numbers it is necessary to first collect garbage. We add an
+// overlaod to get consistent behavior.
+template<typename K>
+void clear(OpenMesh::TriMesh_ArrayKernelT<K>& sm)
+{
+  sm.clear();
+  sm.garbage_collection(true, true, true);
+  CGAL_postcondition(num_edges(sm) == 0);
+  CGAL_postcondition(num_vertices(sm) == 0);
+  CGAL_postcondition(num_faces(sm) == 0);
+}
+
+
+template<typename K>
+bool read_off(std::istream& is, OpenMesh::TriMesh_ArrayKernelT<K>& sm)
+{
+  OpenMesh::IO::Options ropt;
+  return OpenMesh::IO::read_mesh(sm, is, ".OFF", ropt, false);
+}
+
+
+template<typename K>
+bool write_off(std::ostream& os, OpenMesh::TriMesh_ArrayKernelT<K>& sm)
+{
+  OpenMesh::IO::Options ropt;
+  return OpenMesh::IO::write_mesh(sm, os, ".OFF", ropt);
+}
+
+}
 #ifndef CGAL_NO_DEPRECATED_CODE
 #include <CGAL/boost/graph/backward_compatibility_functions.h>
 

BGL/include/CGAL/boost/graph/io.h

@@ -75,7 +75,7 @@ bool write_off(std::ostream& os,
 
   */ 
 template <typename FaceGraph>
-void write_off(const char* fname,
+bool write_off(const char* fname,
                const FaceGraph& g)
 {
   std::ofstream out(fname);