add output_facets_in_complex_to_off and update test and demo

Mesh_3/doc/Mesh_3/CGAL/Mesh_complex_3_in_triangulation_3.h

@@ -90,6 +90,11 @@ std::ostream& output_boundary_to_off(std::ostream& out) const;
  */
 std::ostream& output_boundary_to_off(std::ostream& out, Subdomain_index subdomain) const;
 
+/**
+ * Outputs the surface facets with a consistent orientation at the interface of two subdomains.
+ */
+std::ostream& output_facets_in_complex_to_off(std::ostream& out) const;
+
 /// @}
 
 }; /* end Mesh_complex_3_in_triangulation_3 */

Mesh_3/include/CGAL/Mesh_complex_3_in_triangulation_3.h

@@ -339,7 +339,7 @@ public:
    */
   std::ostream& output_boundary_to_off(std::ostream& out) const
   {
-    output_boundary_of_c3t3_to_off(*this, out);
+    internal::output_boundary_of_c3t3_to_off(*this, 0, out, false);
     return out;
   }
 
@@ -352,6 +352,15 @@ public:
     return out;
   }
 
+  /**
+   * Outputs the surface facets with a consistent orientation at the interface of two subdomains.
+   */
+  std::ostream& output_facets_in_complex_to_off(std::ostream& out) const
+  {
+    internal::output_facets_in_complex_to_off(*this, out);
+    return out;
+  }
+
   /**
    * Fills \c out with incident edges (1-dimensional features of \c v.
    * OutputIterator value type is std::pair<Vertex_handle,Curve_segment_index>

Mesh_3/include/CGAL/internal/Mesh_3/Boundary_of_subdomain_of_complex_3_in_triangulation_3_to_off.h

@@ -29,6 +29,8 @@
 namespace CGAL {
 
 namespace internal{
+
+namespace mesh_3_export{
 template <class Vertex_handle>
 std::size_t get_vertex_index(Vertex_handle v,std::map<Vertex_handle, std::size_t>& V,std::size_t& inum,std::stringstream& vertex_buffer){
   std::pair<typename std::map<Vertex_handle, std::size_t>::iterator,bool> res=
@@ -39,13 +41,14 @@ std::size_t get_vertex_index(Vertex_handle v,std::map<Vertex_handle, std::size_t
   }
   return res.first->second;
 }
-}//namespace internal
+} // end of namespace mesh_3_export
 
 template <typename C3T3>
 std::ostream&
 output_boundary_of_c3t3_to_off(const C3T3& c3t3, 
                                typename C3T3::Subdomain_index sd_index,
-                               std::ostream& output)
+                               std::ostream& output,
+                               bool normals_point_outside_of_the_subdomain=true)
 {
   typedef typename C3T3::Triangulation Triangulation;
   typedef typename Triangulation::Vertex_handle Vertex_handle;
@@ -72,8 +75,9 @@ output_boundary_of_c3t3_to_off(const C3T3& c3t3,
     
     for (int i = 0; i < 4; ++i)
       if (i != fit->second)
-          indices[++j]=internal::get_vertex_index((*fit).first->vertex(i), V, inum,vertex_buffer);
+          indices[++j]=mesh_3_export::get_vertex_index((*fit).first->vertex(i), V, inum,vertex_buffer);
-    if ( (cell_sd==sd_index) == (fit->second%2 == 1) ) std::swap(indices[0],indices[1]);
+    if ( ( (cell_sd==sd_index) == (fit->second%2 == 1) ) == normals_point_outside_of_the_subdomain )
+      std::swap(indices[0],indices[1]);
     facet_buffer << "3" << " " << indices[0] <<" " << indices[1] <<" " << indices[2] << "\n";
   }
   
@@ -87,8 +91,8 @@ output_boundary_of_c3t3_to_off(const C3T3& c3t3,
 
 template <typename C3T3>
 std::ostream&
-output_boundary_of_c3t3_to_off(const C3T3& c3t3,
+output_facets_in_complex_to_off(const C3T3& c3t3,
-                               std::ostream& output)
+                                std::ostream& output)
 {
   typedef typename C3T3::Triangulation Triangulation;
   typedef typename Triangulation::Vertex_handle Vertex_handle;
@@ -113,7 +117,7 @@ output_boundary_of_c3t3_to_off(const C3T3& c3t3,
 
     for (int i = 0; i < 4; ++i)
       if (i != fit->second)
-          indices[++j]=internal::get_vertex_index((*fit).first->vertex(i), V, inum,vertex_buffer);
+          indices[++j]=mesh_3_export::get_vertex_index((*fit).first->vertex(i), V, inum,vertex_buffer);
     if ( (cell_sd > opp_sd) == (fit->second%2 == 1) ) std::swap(indices[0],indices[1]);
     facet_buffer << "3" << " " << indices[0] <<" " << indices[1] <<" " << indices[2] << "\n";
   }
@@ -126,6 +130,7 @@ output_boundary_of_c3t3_to_off(const C3T3& c3t3,
   return output;
 }
 
-} // end namespace CGAL
+} } // end of namespace CGAL::internal
+
 
 #endif // CGAL_INTERNAL_MESH_3_BOUNDARY_OF_SUDDOMAIN_OF_COMPLEX_3_IN_TRIANGULATION_3_TO_OFF_H

Mesh_3/test/Mesh_3/test_c3t3_extract_subdomains_boundaries.cpp

@@ -83,6 +83,10 @@ int main()
   c3t3.output_boundary_to_off(off_file);
   assert( off_file.str().size() > 20 );
 
+  off_file.str("");
+  c3t3.output_facets_in_complex_to_off(off_file);
+  assert( off_file.str().size() > 20 );
+
   for (int i=0;i<4; ++i){
     off_file.str("");
     c3t3.output_boundary_to_off(off_file,i);

Polyhedron/demo/Polyhedron/Polyhedron_demo_mesh_3_plugin_cgal_code.cpp

@@ -278,10 +278,10 @@ private:
   }
 
 public slots:
-  void export_domain_boundary_as_polyhedron()
+  void export_facets_in_complex()
   {
     std::stringstream off_sstream;
-    c3t3().output_boundary_to_off(off_sstream);
+    c3t3().output_facets_in_complex_to_off(off_sstream);
     std::string backup = off_sstream.str();
     // Try to read .off in a polyhedron
     Scene_polyhedron_item* item = new Scene_polyhedron_item();
@@ -298,11 +298,11 @@ public slots:
         return;
       }
 
-      soup_item->setName(QString("%1_%2").arg(this->name()).arg("boundary"));
+      soup_item->setName(QString("%1_%2").arg(this->name()).arg("facets"));
       last_known_scene->addItem(soup_item);
     }
     else{
-      item->setName(QString("%1_%2").arg(this->name()).arg("boundary"));
+      item->setName(QString("%1_%2").arg(this->name()).arg("facets"));
       last_known_scene->addItem(item);
     }
   }
@@ -320,12 +320,12 @@ public:
     bool menuChanged = menu->property(prop_name).toBool();
 
     if(!menuChanged) {
-      QAction* actionDomainBoundaryAsPolyhedron =
+      QAction* actionExportFacetsInComplex =
-        menu->addAction(tr("Export domain boundary as polyhedron"));
+        menu->addAction(tr("Export facets in complex"));
-      actionDomainBoundaryAsPolyhedron->setObjectName("actionSelectNextVolume");
+      actionExportFacetsInComplex->setObjectName("actionExportFacetsInComplex");
-      connect(actionDomainBoundaryAsPolyhedron,
+      connect(actionExportFacetsInComplex,
               SIGNAL(triggered()),this,
-              SLOT(export_domain_boundary_as_polyhedron()));
+              SLOT(export_facets_in_complex()));
     }
     return menu;
   }