From 39c27cb9db1a181f25716f1d795db87d9e5ea8bf Mon Sep 17 00:00:00 2001
From: Andreas Fabri <andreas.fabri@geometryfactory.com>
Date: Mon, 17 Oct 2016 14:59:06 +0200
Subject: [PATCH] Call approximate_dihedral_angle() from the Kernel

---
 .../demo/Polyhedron/Scene_c3t3_item.cpp       | 13 ++++++-------
 .../edge_collapse_constrain_sharp_edges.cpp   | 19 ++++++++-----------
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp b/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp
index 511d178de0c..584d6650df9 100644
--- a/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_c3t3_item.cpp
@@ -13,7 +13,6 @@
 #include <map>
 #include <vector>
 #include <CGAL/gl.h>
-#include <CGAL/Mesh_3/dihedral_angle_3.h>
 #include <CGAL/Three/Scene_interface.h>
 #include <CGAL/Real_timer.h>
 
@@ -562,32 +561,32 @@ create_histogram(const C3t3& c3t3, double& min_value, double& max_value)
     const Point_3& p2 = cit->vertex(2)->point();
     const Point_3& p3 = cit->vertex(3)->point();
 
-    double a = CGAL::to_double(CGAL::abs(CGAL::Mesh_3::dihedral_angle(p0, p1, p2, p3)));
+    double a = CGAL::to_double(CGAL::abs(CGAL::approximate_dihedral_angle(p0, p1, p2, p3)));
     histo[static_cast<int>(std::floor(a))] += 1;
     min_value = (std::min)(min_value, a);
     max_value = (std::max)(max_value, a);
 
-    a = CGAL::to_double(CGAL::abs(CGAL::Mesh_3::dihedral_angle(p0, p2, p1, p3)));
+    a = CGAL::to_double(CGAL::abs(CGAL::approximate_dihedral_angle(p0, p2, p1, p3)));
     histo[static_cast<int>(std::floor(a))] += 1;
     min_value = (std::min)(min_value, a);
     max_value = (std::max)(max_value, a);
 
-    a = CGAL::to_double(CGAL::abs(CGAL::Mesh_3::dihedral_angle(p0, p3, p1, p2)));
+    a = CGAL::to_double(CGAL::abs(CGAL::approximate_dihedral_angle(p0, p3, p1, p2)));
     histo[static_cast<int>(std::floor(a))] += 1;
     min_value = (std::min)(min_value, a);
     max_value = (std::max)(max_value, a);
 
-    a = CGAL::to_double(CGAL::abs(CGAL::Mesh_3::dihedral_angle(p1, p2, p0, p3)));
+    a = CGAL::to_double(CGAL::abs(CGAL::approximate_dihedral_angle(p1, p2, p0, p3)));
     histo[static_cast<int>(std::floor(a))] += 1;
     min_value = (std::min)(min_value, a);
     max_value = (std::max)(max_value, a);
 
-    a = CGAL::to_double(CGAL::abs(CGAL::Mesh_3::dihedral_angle(p1, p3, p0, p2)));
+    a = CGAL::to_double(CGAL::abs(CGAL::approximate_dihedral_angle(p1, p3, p0, p2)));
     histo[static_cast<int>(std::floor(a))] += 1;
     min_value = (std::min)(min_value, a);
     max_value = (std::max)(max_value, a);
 
-    a = CGAL::to_double(CGAL::abs(CGAL::Mesh_3::dihedral_angle(p2, p3, p0, p1)));
+    a = CGAL::to_double(CGAL::abs(CGAL::approximate_dihedral_angle(p2, p3, p0, p1)));
     histo[static_cast<int>(std::floor(a))] += 1;
     min_value = (std::min)(min_value, a);
     max_value = (std::max)(max_value, a);
diff --git a/Surface_mesh_simplification/examples/Surface_mesh_simplification/edge_collapse_constrain_sharp_edges.cpp b/Surface_mesh_simplification/examples/Surface_mesh_simplification/edge_collapse_constrain_sharp_edges.cpp
index 042458af7c0..39d8a1214db 100644
--- a/Surface_mesh_simplification/examples/Surface_mesh_simplification/edge_collapse_constrain_sharp_edges.cpp
+++ b/Surface_mesh_simplification/examples/Surface_mesh_simplification/edge_collapse_constrain_sharp_edges.cpp
@@ -1,8 +1,6 @@
 #include <iostream>
 #include <fstream>
 
-
-
 #include <CGAL/Simple_cartesian.h>
 #include <CGAL/Polyhedron_3.h>
 #include <CGAL/IO/Polyhedron_iostream.h>
@@ -13,7 +11,6 @@
 #include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Midpoint_placement.h>
 #include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Count_stop_predicate.h>
 #include <CGAL/Unique_hash_map.h>
-#include <CGAL/Mesh_3/dihedral_angle_3.h>
 #include <CGAL/property_map.h>
 #include <cmath>
 
@@ -106,10 +103,10 @@ int main( int argc, char** argv )
                                             point(target(hd,surface_mesh),surface_mesh));
     }
     else{
-      double angle = CGAL::Mesh_3::dihedral_angle(point(target(opposite(hd,surface_mesh),surface_mesh),surface_mesh),
-                                                  point(target(hd,surface_mesh),surface_mesh),
-                                                  point(target(next(hd,surface_mesh),surface_mesh),surface_mesh),
-                                                  point(target(next(opposite(hd,surface_mesh),surface_mesh),surface_mesh),surface_mesh));
+      double angle = CGAL::approximate_dihedral_angle(point(target(opposite(hd,surface_mesh),surface_mesh),surface_mesh),
+                                                      point(target(hd,surface_mesh),surface_mesh),
+                                                      point(target(next(hd,surface_mesh),surface_mesh),surface_mesh),
+                                                      point(target(next(opposite(hd,surface_mesh),surface_mesh),surface_mesh),surface_mesh));
       if ( CGAL::abs(angle)<100 ){
         ++nb_sharp_edges;
         constraint_hmap[*eb]=true;
@@ -152,10 +149,10 @@ int main( int argc, char** argv )
                                                      point(target(hd,surface_mesh),surface_mesh)));
     }
     else{
-      double angle = CGAL::Mesh_3::dihedral_angle(point(target(opposite(hd,surface_mesh),surface_mesh),surface_mesh),
-                                                  point(target(hd,surface_mesh),surface_mesh),
-                                                  point(target(next(hd,surface_mesh),surface_mesh),surface_mesh),
-                                                  point(target(next(opposite(hd,surface_mesh),surface_mesh),surface_mesh),surface_mesh));
+      double angle = approximate_dihedral_angle(point(target(opposite(hd,surface_mesh),surface_mesh),surface_mesh),
+                                                point(target(hd,surface_mesh),surface_mesh),
+                                                point(target(next(hd,surface_mesh),surface_mesh),surface_mesh),
+                                                point(target(next(opposite(hd,surface_mesh),surface_mesh),surface_mesh),surface_mesh));
       if ( CGAL::abs(angle)<100 ){
         --nb_sharp_edges;
       assert(