From 8277f73a2c524c41f336828eddd1d1cbf04b5897 Mon Sep 17 00:00:00 2001
From: Andreas Fabri <andreas.fabri@geometryfactory.com>
Date: Fri, 13 Feb 2015 18:08:52 +0100
Subject: [PATCH] Add connected_components without EdgeConstraintMap

---
 .../PackageDescription.txt                    |  3 +-
 .../connected_component.cpp                   |  2 +-
 .../Connected_components.h                    | 30 +++++++++++++++++--
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/Polygon_mesh_processing/doc/Polygon_mesh_processing/PackageDescription.txt b/Polygon_mesh_processing/doc/Polygon_mesh_processing/PackageDescription.txt
index f0802ee646c..b5f68d43179 100644
--- a/Polygon_mesh_processing/doc/Polygon_mesh_processing/PackageDescription.txt
+++ b/Polygon_mesh_processing/doc/Polygon_mesh_processing/PackageDescription.txt
@@ -61,7 +61,8 @@
 ## Other Classes and Functions ##
 - `CGAL::Polygon_mesh_slicer`
 - `CGAL::Polygon_Mesh_processing::keep_largest_connected_components()`
-- `CGAL::Polygon_Mesh_processing::discover_connected_component()`
+- `CGAL::Polygon_Mesh_processing::connected_component()`
+- `CGAL::Polygon_Mesh_processing::connected_components()`
 
 \todo remove FairWeightCalculator and replace it by a property map. Note that the default property map should be documented
 \todo make template parameter names uniform in other packages using BGL. Here we chose PolygonMesh as template parameter.
diff --git a/Polygon_mesh_processing/examples/Polygon_mesh_processing/connected_component.cpp b/Polygon_mesh_processing/examples/Polygon_mesh_processing/connected_component.cpp
index 47b80ac16f5..627a81e093f 100644
--- a/Polygon_mesh_processing/examples/Polygon_mesh_processing/connected_component.cpp
+++ b/Polygon_mesh_processing/examples/Polygon_mesh_processing/connected_component.cpp
@@ -49,7 +49,7 @@ int main(int, char* argv[])
   Mesh::Property_map<face_descriptor,int> fccmap;
   fccmap = sm.add_property_map<face_descriptor,int>("f:CC").first; 
   int num = CGAL::Polygon_mesh_processing::connected_components(sm,
-                                                                Constraint<Mesh>(sm),
+                                                                //Constraint<Mesh>(sm),
                                                                 fccmap);
   
  std::cerr << "The graph has " << num << " connected components (face connectivity)" << std::endl;
diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/Connected_components.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/Connected_components.h
index 8531c71800c..f115078ce19 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/Connected_components.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/Connected_components.h
@@ -398,7 +398,8 @@ template <typename G>
 struct No_constraint {
   No_constraint() { }
 
-  No_constraint(G & g) : g(&g) { }
+  No_constraint(G & g)
+    : g(&g) { }
 
   template <typename T>
   bool operator[](const T & ) const {
@@ -408,12 +409,13 @@ struct No_constraint {
   G* g;
 };
 
-template <typename G, typename EdgeConstraintMap>
+  template <typename G, typename EdgeConstraintMap = No_constraint<G> >
 struct No_border {
   No_border() 
   {}
   
-  No_border(G & g, EdgeConstraintMap ecm) : g(&g), ecm(ecm)
+    No_border(G & g, EdgeConstraintMap ecm = EdgeConstraintMap())
+      : g(&g), ecm(ecm)
   { }
   
   bool operator()(typename boost::graph_traits<G>::edge_descriptor e) const {
@@ -427,6 +429,8 @@ struct No_border {
   EdgeConstraintMap ecm;
 };
 
+
+
 }// namespace internal
  
 
@@ -474,6 +478,26 @@ struct No_border {
     return boost::connected_components(finite_dual, fim);
   }
 
+ /*!
+   * \ingroup PkgPolygonMeshProcessing
+   *  computes for each face the index of the connected components to which it belongs.
+   *  Two faces are considered to be in the same connected component if they share an edge.
+   *  \tparam PolygonMesh a model of `FaceGraph`
+   *  \tparam FaceIndexMap the property map with the face index as value type, and the index of its connected component
+   *  \returns the number of connected components.
+  */
+  template <class PolygonMesh, class FaceIndexMap>
+  typename boost::graph_traits<PolygonMesh>::faces_size_type
+  connected_components(PolygonMesh& pmesh,
+                       FaceIndexMap& fim)
+  {
+    typedef Dual<PolygonMesh> Dual;
+    typedef boost::filtered_graph<Dual, internal::No_border<PolygonMesh> > FiniteDual;
+
+    Dual dual(pmesh);
+    FiniteDual finite_dual(dual,internal::No_border<PolygonMesh>(pmesh));
+    return boost::connected_components(finite_dual, fim);
+  }
 } // namespace Polygon_mesh_processing
 
 } // namespace CGAL