Add color writing for OFF format. Fixes Vertex_color display.

Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp

@@ -556,13 +556,15 @@ void Scene_surface_mesh_item_priv::initializeBuffers(CGAL::Three::Viewer_interfa
   item->buffers[Scene_surface_mesh_item_priv::Smooth_normals].release();
   if(has_vcolors)
   {
-    item->buffers[VColors].bind();
-    item->buffers[VColors].allocate(v_colors.data(),
+    item->buffers[Scene_surface_mesh_item_priv::VColors].bind();
+    item->buffers[Scene_surface_mesh_item_priv::VColors].allocate(v_colors.data(),
                              static_cast<int>(v_colors.size()*sizeof(cgal_gl_data)));
-    //program->enableAttributeArray("colors");
+    program->enableAttributeArray("colors");
     program->setAttributeBuffer("colors",CGAL_GL_DATA,0,3);
-    item->buffers[VColors].release();
+    item->buffers[Scene_surface_mesh_item_priv::VColors].release();
   }
+  else
+    program->disableAttributeArray("colors");
   item->vaos[Scene_surface_mesh_item_priv::Smooth_facets]->release();
   program->release();
 

Surface_mesh/include/CGAL/Surface_mesh/IO.h

@@ -39,6 +39,7 @@
 #include <CGAL/Surface_mesh/Surface_mesh.h>
 #include <CGAL/Surface_mesh/Properties.h>
 #include <CGAL/Kernel_traits.h>
+#include <CGAL/boost/graph/graph_traits_Surface_mesh.h>
 
 //=============================================================================
 
@@ -446,7 +447,50 @@ bool write_mesh(const Surface_mesh<K>& mesh, const std::string& filename)
 
 /// group io
 /// @}
+template <class P, class Writer>
+void
+generic_print_surface_mesh( std::ostream&   out,
+                          const Surface_mesh<P>&       M,
+                          Writer&           writer) {
+  // writes M to `out' in the format provided by `writer'.
+  typedef typename boost::graph_traits<Surface_mesh<P> >::vertex_iterator VCI;
+  typedef typename boost::graph_traits<Surface_mesh<P> >::face_iterator   FCI;
+  typedef typename Surface_mesh<P>::Halfedge_around_face_circulator            HFCC;
+  typedef typename boost::property_map<Surface_mesh<P>,CGAL::vertex_point_t>::type VPmap;
+  VPmap map = get(CGAL::vertex_point, M);
+  // Print header.
+  writer.write_header( out,
+                       num_vertices(M),
+                       num_halfedges(M),
+                       num_faces(M));
 
+  std::map<typename Surface_mesh<P>::vertex_index, std::size_t> index_map;
+  typename std::map<typename Surface_mesh<P>::vertex_index, std::size_t>::iterator hint = index_map.begin();
+  std::size_t id = 0;
+
+  for( VCI vi = vertices(M).begin(); vi != vertices(M).end(); ++vi) {
+    writer.write_vertex( ::CGAL::to_double( get(map, *vi).x()),
+                         ::CGAL::to_double( get(map, *vi).y()),
+                         ::CGAL::to_double( get(map, *vi).z()));
+
+    hint = index_map.insert(hint, std::make_pair(*vi, id++));
+  }
+
+  writer.write_facet_header();
+  for( FCI fi = faces(M).begin(); fi != faces(M).end(); ++fi) {
+    HFCC hc(halfedge(*fi, M), M);
+    HFCC hc_end = hc;
+    std::size_t n = circulator_size( hc);
+    CGAL_assertion( n >= 3);
+    writer.write_facet_begin( n);
+    do {
+      writer.write_facet_vertex_index(index_map[target(*hc, M)]);
+      ++hc;
+    } while( hc != hc_end);
+    writer.write_facet_end();
+  }
+  writer.write_footer();
+}
 } // CGAL
 
 

Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h

@@ -1969,12 +1969,28 @@ private: //------------------------------------------------------- private data
     typedef typename Mesh::Vertex_index Vertex_index;
     typedef typename Mesh::Face_index Face_index;
 
-    os << "OFF\n" << sm.number_of_vertices() << " " << sm.number_of_faces() << " 0\n";
+    typename Mesh::template Property_map<typename Mesh::Vertex_index, CGAL::Color> vcolors;
+    bool has_vcolors;
+    boost::tie(vcolors, has_vcolors) = sm.template property_map<typename Mesh::Vertex_index, CGAL::Color >("v:color");
+    typename Mesh::template Property_map<typename Mesh::Face_index, CGAL::Color> fcolors;
+    bool has_fcolors;
+    boost::tie(fcolors, has_fcolors) = sm.template property_map<typename Mesh::Face_index, CGAL::Color >("f:color");
+
+    if(!has_fcolors && !has_vcolors)
+      os << "OFF\n" << sm.number_of_vertices() << " " << sm.number_of_faces() << " 0\n";
+    else
+      os << "COFF\n" << sm.number_of_vertices() << " " << sm.number_of_faces() << " 0\n";
     std::vector<int> reindex;
     reindex.resize(sm.num_vertices());
     int n = 0;
     BOOST_FOREACH(Vertex_index v, sm.vertices()){
-      os << sm.point(v) << '\n';
+      os << sm.point(v);
+      if(has_vcolors)
+      {
+        CGAL::Color color = vcolors[v];
+        os <<" "<< static_cast<int>(color.r())<<" "<< static_cast<int>(color.g())<<" "<< static_cast<int>(color.b());
+      }
+      os << '\n';
       reindex[v]=n++;
     }
 
@@ -1983,6 +1999,11 @@ private: //------------------------------------------------------- private data
       BOOST_FOREACH(Vertex_index v, CGAL::vertices_around_face(sm.halfedge(f),sm)){
         os << " " << reindex[v];
       }
+      if(has_fcolors)
+      {
+        CGAL::Color color = fcolors[f];
+        os <<" "<< static_cast<int>(color.r())<<" "<< static_cast<int>(color.g())<<" "<< static_cast<int>(color.b());
+      }
       os << '\n';
     }
     return os;