From 6db2bff67bdada0ed2c736162811a923c7a1698c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Loriot?= <sebastien.loriot@cgal.org>
Date: Wed, 23 Nov 2016 15:47:11 +0100
Subject: [PATCH] handle call to corefinement functions with identical meshes

---
 .../Polygon_mesh_processing/corefinement.h    | 45 +++++++++++++++++++
 .../internal/Corefinement/Visitor.h           | 14 ++++++
 2 files changed, 59 insertions(+)

diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/corefinement.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/corefinement.h
index d45268c81a0..bffc206b326 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/corefinement.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/corefinement.h
@@ -24,6 +24,7 @@
 #include <CGAL/Polygon_mesh_processing/intersection.h>
 #include <CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h>
 #include <CGAL/Polygon_mesh_processing/internal/Corefinement/Face_graph_output_builder.h>
+#include <CGAL/boost/graph/copy_face_graph.h>
 #include <CGAL/iterator.h>
 
 namespace CGAL {
@@ -99,6 +100,7 @@ boolean_operation(      TriangleMesh& tm1,
                                      NamedParametersOut3>& nps_out,
                   const bool throw_on_self_intersection = false )
 {
+
 // Vertex point maps
   //for input meshes
   typedef typename GetVertexPointMap<TriangleMesh,
@@ -124,6 +126,42 @@ boolean_operation(      TriangleMesh& tm1,
   CGAL_COREF_SET_OUTPUT_VERTEX_POINT_MAP(2)
   CGAL_COREF_SET_OUTPUT_VERTEX_POINT_MAP(3)
 
+  if (&tm1==&tm2)
+  {
+    // for now edges in a coplanar patch are not constrained so there is nothing to constrained here
+    // \todo marked edges from input to output are not ported
+
+    if (desired_output[Corefinement::UNION] != boost::none)
+      if (&tm1 != *desired_output[Corefinement::UNION])
+        copy_face_graph(tm1,
+                        *(*desired_output[Corefinement::UNION]),
+                        Emptyset_iterator(),
+                        Emptyset_iterator(),
+                        Emptyset_iterator(),
+                        vpm1,
+                        vpm_out[Corefinement::UNION]);
+
+    if (desired_output[Corefinement::INTER] != boost::none)
+      if (&tm1 != *desired_output[Corefinement::INTER])
+        copy_face_graph(tm1,
+                        *(*desired_output[Corefinement::INTER]),
+                        Emptyset_iterator(),
+                        Emptyset_iterator(),
+                        Emptyset_iterator(),
+                        vpm1,
+                        vpm_out[Corefinement::INTER]);
+
+    if (desired_output[Corefinement::TM1_MINUS_TM2] != boost::none)
+      if (&tm1 == *desired_output[Corefinement::TM1_MINUS_TM2])
+        clear(tm1);
+
+    if (desired_output[Corefinement::TM2_MINUS_TM1] != boost::none)
+      if (&tm1 == *desired_output[Corefinement::TM2_MINUS_TM1])
+        clear(tm1);
+
+    return CGAL::make_array(true, true, true, true);
+  }
+
 // Edge is-constrained maps
   //for input meshes
   typedef typename boost::lookup_named_param_def <
@@ -429,6 +467,13 @@ corefine_and_compute_difference(      TriangleMesh& tm1,
 
   typedef Corefinement::Ecm_bind<TriangleMesh, Ecm1, Ecm2> Ecm;
 
+  if (&tm1==&tm2)
+  {
+    Corefinement::mark_all_edges(tm1, ecm1);
+    Corefinement::mark_all_edges(tm2, ecm2);
+    return;
+  }
+
 // surface intersection algorithm call
   typedef Corefinement::Default_node_visitor<TriangleMesh> Dnv;
   typedef Corefinement::Default_face_visitor<TriangleMesh> Dfv;
diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h
index e7ffb017871..3adfe1127f9 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h
@@ -76,6 +76,20 @@ struct No_mark
   {}
 };
 
+template<class TriangleMesh, class EdgeMarkMap>
+void mark_all_edges(TriangleMesh& tm, const EdgeMarkMap& edge_mark_map)
+{
+  BOOST_FOREACH(typename boost::graph_traits<TriangleMesh>::edge_descriptor ed,
+                edges(tm))
+  {
+    put(edge_mark_map, ed, true);
+  }
+}
+
+template<class TriangleMesh>
+void mark_all_edges(TriangleMesh& tm, const No_mark<TriangleMesh>&)
+{} //nothing to do
+
 //binds two edge constrained pmaps
 template <class G, class Ecm1, class Ecm2=Ecm1>
 struct Ecm_bind{