From 42af962bc2d47173efa564dbd81c82b5e20e41af Mon Sep 17 00:00:00 2001
From: Andreas Fabri <andreas.fabri@geometryfactory.com>
Date: Fri, 23 Nov 2018 13:06:55 +0100
Subject: [PATCH] Add overload for two vectors

---
 .../Concepts/FunctionObjectConcepts.h         | 14 ++++++++---
 .../include/CGAL/Kernel/function_objects.h    | 24 +++++++++++++------
 .../include/CGAL/Kernel/global_functions_3.h  |  9 +++++++
 .../CGAL/Kernel/global_functions_internal_3.h |  9 +++++++
 .../test/Kernel_23/include/CGAL/_test_angle.h |  1 +
 5 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h b/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h
index f1c7470995f..79f74ce3a0e 100644
--- a/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h
+++ b/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h
@@ -1782,10 +1782,18 @@ public:
   /// A model of this concept must provide:
   /// @{
 
+  /*!
+    returns an approximation of the angle between `u` and `v`.
+    The angle is given in degrees.
+    \pre `u`and `v` are not equal to the null vector.
+  */
+  Kernel::FT operator()(const Kernel::Vector_3& u,
+                        const Kernel::Vector_3& v) const;
+  
   /*!
     returns an approximation of the angle between `p-q` and `r-q`.
     The angle is given in degrees.
-    \pre `p`and `r` are not equal to `q`.
+    \pre `p` and `r` are not equal to `q`.
   */
   Kernel::FT operator()(const Kernel::Point_3& p,
                         const Kernel::Point_3& q,
@@ -6920,7 +6928,7 @@ public:
   Kernel::Vector_2 operator()(const Kernel::Line_2 &l); 
 
   /*!
-    introduces a null vector . 
+    introduces a null vector. 
   */ 
   Kernel::Vector_2 operator()(const Null_vector &NULL_VECTOR); 
 
@@ -6979,7 +6987,7 @@ public:
   Kernel::Vector_3 operator()(const Kernel::Line_3 &l); 
 
   /*!
-    introduces a null vector . 
+    introduces a null vector. 
   */ 
   Kernel::Vector_3 operator()(const Null_vector &NULL_VECTOR); 
 
diff --git a/Kernel_23/include/CGAL/Kernel/function_objects.h b/Kernel_23/include/CGAL/Kernel/function_objects.h
index 3d49c063a9d..d1e8959f5a7 100644
--- a/Kernel_23/include/CGAL/Kernel/function_objects.h
+++ b/Kernel_23/include/CGAL/Kernel/function_objects.h
@@ -832,21 +832,18 @@ namespace CommonKernelFunctors {
  template <typename K>
  class Compute_approximate_angle_3
  {
-    typedef typename K::Point_3 Point_3;  
+   typedef typename K::Point_3 Point_3;
+   typedef typename K::Vector_3 Vector_3;
+   
  public:
    typedef typename K::FT       result_type;
 
     result_type
-    operator()(const Point_3& p, const Point_3& q, const Point_3& r) const
+    operator()(const Vector_3& u, const Vector_3& v) const
    {
      K k;
-     typename K::Construct_vector_3 vector = k.construct_vector_3_object();
      typename K::Compute_scalar_product_3 scalar_product =
        k.compute_scalar_product_3_object();
-     typedef typename K::Vector_3                     Vector_3;
-     
-     Vector_3 u = vector(q,p);
-     Vector_3 v = vector(q,r);
 
      double product = CGAL::sqrt(to_double(scalar_product(u,u))) * CGAL::sqrt(to_double(scalar_product(v,v)));
      
@@ -866,6 +863,19 @@ namespace CommonKernelFunctors {
 
      return std::acos(cosine) * 180./CGAL_PI;
    }
+
+   
+   result_type
+   operator()(const Point_3& p, const Point_3& q, const Point_3& r) const
+   {
+     K k;
+     typename K::Construct_vector_3 vector = k.construct_vector_3_object();
+     
+     Vector_3 u = vector(q,p);
+     Vector_3 v = vector(q,r);
+
+     return this->operator()(u,v); 
+   }
  };
   
  template <typename K>
diff --git a/Kernel_23/include/CGAL/Kernel/global_functions_3.h b/Kernel_23/include/CGAL/Kernel/global_functions_3.h
index 4ca56b312a4..ab7af514c4f 100644
--- a/Kernel_23/include/CGAL/Kernel/global_functions_3.h
+++ b/Kernel_23/include/CGAL/Kernel/global_functions_3.h
@@ -69,6 +69,15 @@ angle(const Point_3<K> &p, const Point_3<K> &q,
   return internal::angle(p, q, r, v, K());
 }
 
+template < class K >
+inline
+typename K::FT
+approximate_angle(const Vector_3<K> &u,
+                  const Vector_3<K> &v)
+{
+  return internal::approximate_angle(u, v, K());
+}
+  
 template < class K >
 inline
 typename K::FT
diff --git a/Kernel_23/include/CGAL/Kernel/global_functions_internal_3.h b/Kernel_23/include/CGAL/Kernel/global_functions_internal_3.h
index 7cce51f08d4..d243e8b1974 100644
--- a/Kernel_23/include/CGAL/Kernel/global_functions_internal_3.h
+++ b/Kernel_23/include/CGAL/Kernel/global_functions_internal_3.h
@@ -83,6 +83,15 @@ angle(const typename K::Point_3 &p,
   return k.angle_3_object()(p, q, r, v);
 }
 
+template < class K >
+inline
+typename K::FT
+approximate_angle(const typename K::Vector_3 &u,
+                  const typename K::Vector_3 &v , const K& k)
+{
+  return k.compute_approximate_angle_3_object()(u, v);
+}
+  
 template < class K >
 inline
 typename K::FT
diff --git a/Kernel_23/test/Kernel_23/include/CGAL/_test_angle.h b/Kernel_23/test/Kernel_23/include/CGAL/_test_angle.h
index d12e122334c..4a4166ad8c5 100644
--- a/Kernel_23/test/Kernel_23/include/CGAL/_test_angle.h
+++ b/Kernel_23/test/Kernel_23/include/CGAL/_test_angle.h
@@ -77,6 +77,7 @@ _test_angle(const R&)
   assert( CGAL::angle( org3, sx, sy, vcoplanar) ==  CGAL::RIGHT );
   assert( CGAL::angle( org3, sx, sy, vmz) ==  CGAL::OBTUSE );
   assert( CGAL::approximate_angle( sx, org3, sy ) > RT(89.9) );
+  assert( CGAL::approximate_angle( sx-org3, sy-org3 ) > RT(89.9) );
   assert( CGAL::approximate_angle( sx, org3, sy ) < RT(90.1) );
   assert( CGAL::approximate_angle( sx, org3, sx ) == RT(0) );
   assert( CGAL::approximate_angle( sx, org3, msx ) > RT(179.9) );