From 2160da4ceb5a29e736816202f526722b5fae334b Mon Sep 17 00:00:00 2001
From: Jane Tournois <jane.tournois@geometryfactory.com>
Date: Fri, 4 Sep 2015 17:37:36 +0200
Subject: [PATCH] add area function for the complete triangulated Surface

use CGAL_PMP_NP_TEMPLATE_PARAMETERS and CGAL_PMP_NP_CLASS
to avoid ambiguities
---
 .../CGAL/Polygon_mesh_processing/measure.h    | 54 +++++++++++++++----
 .../Polygon_mesh_processing/measures_test.cpp |  5 ++
 2 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/measure.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/measure.h
index cb4c4fdc5a6..aaf7544afdb 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/measure.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/measure.h
@@ -29,6 +29,11 @@
 #include <CGAL/Polygon_mesh_processing/internal/named_function_params.h>
 #include <CGAL/Polygon_mesh_processing/internal/named_params_helper.h>
 
+#ifdef DOXYGEN_RUNNING
+#define CGAL_PMP_NP_TEMPLATE_PARAMETERS NamedParameters
+#define CGAL_PMP_NP_CLASS NamedParameters
+#endif
+
 namespace CGAL {
 
 namespace Polygon_mesh_processing {
@@ -127,7 +132,8 @@ namespace Polygon_mesh_processing {
 
   /**
   * \ingroup measure_grp
-  * computes the area of a face of a given polygon mesh.
+  * computes the area of a face of a given
+  * triangulated surface mesh.
   *
   * @tparam TriangleMesh a model of `HalfedgeGraph` that has an internal property map
   *         for `boost::vertex_point_t`
@@ -142,15 +148,15 @@ namespace Polygon_mesh_processing {
   * \cgalNamedParamsEnd
   */
   template<typename TriangleMesh,
-           typename NamedParameters>
+           typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
   double area(typename boost::graph_traits<TriangleMesh>::face_descriptor f
             , const TriangleMesh& tmesh
-            , const NamedParameters& np)
+            , const CGAL_PMP_NP_CLASS& np)
   {
     using boost::choose_const_pmap;
     using boost::get_param;
 
-    typename GetVertexPointMap<TriangleMesh, NamedParameters>::const_type
+    typename GetVertexPointMap<TriangleMesh, CGAL_PMP_NP_CLASS>::const_type
     vpm = choose_const_pmap(get_param(np, CGAL::vertex_point),
                             tmesh,
                             CGAL::vertex_point);
@@ -166,15 +172,16 @@ namespace Polygon_mesh_processing {
 
   template<typename TriangleMesh>
   double area(typename boost::graph_traits<TriangleMesh>::face_descriptor f
-    , const TriangleMesh& pmesh)
+    , const TriangleMesh& tmesh)
   {
-    return area(f, pmesh,
+    return area(f, tmesh,
       CGAL::Polygon_mesh_processing::parameters::all_default());
   }
 
   /**
   * \ingroup measure_grp
-  * computes the area of a range of faces of a given polygon mesh.
+  * computes the area of a range of faces of a given
+  * triangulated surface mesh.
   *
   * @tparam FaceRange range of `boost::graph_traits<PolygonMesh>::%face_descriptor`,
           model of `Range`.
@@ -193,10 +200,10 @@ namespace Polygon_mesh_processing {
   */
   template<typename FaceRange,
            typename TriangleMesh,
-           typename NamedParameters>
+           typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
   double area(FaceRange face_range
             , const TriangleMesh& tmesh
-            , const NamedParameters& np)
+            , const CGAL_PMP_NP_CLASS& np)
   {
     typedef typename boost::graph_traits<TriangleMesh>::face_descriptor face_descriptor;
     double result = 0.;
@@ -214,6 +221,35 @@ namespace Polygon_mesh_processing {
       CGAL::Polygon_mesh_processing::parameters::all_default());
   }
 
+  /**
+  * \ingroup measure_grp
+  * computes the surface area of a triangulated surface mesh.
+  *
+  * @tparam TriangleMesh a model of `HalfedgeGraph` that has an internal property map
+  *         for `boost::vertex_point_t`
+  * @tparam NamedParameters a sequence of \ref namedparameters
+  *
+  * @param tmesh the triangulated surface mesh to which the faces of `face_range` belong
+  * @param np optional sequence of \ref namedparameters among the ones listed below
+  *
+  * \cgalNamedParamsBegin
+  *    \cgalParamBegin{vertex_point_map} the property map with the points associated to the vertices of `pmesh` \cgalParamEnd
+  * \cgalNamedParamsEnd
+  */
+  template<typename TriangleMesh
+         , typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
+  double area(const TriangleMesh& tmesh
+            , const CGAL_PMP_NP_CLASS& np)
+  {
+    return area(faces(tmesh), tmesh, np);
+  }
+
+  template<typename TriangleMesh>
+  double area(const TriangleMesh& tmesh)
+  {
+    return area(faces(tmesh), tmesh);
+  }
+
 }
 }
 
diff --git a/Polygon_mesh_processing/test/Polygon_mesh_processing/measures_test.cpp b/Polygon_mesh_processing/test/Polygon_mesh_processing/measures_test.cpp
index d5c76d1e49d..ba611a8d905 100644
--- a/Polygon_mesh_processing/test/Polygon_mesh_processing/measures_test.cpp
+++ b/Polygon_mesh_processing/test/Polygon_mesh_processing/measures_test.cpp
@@ -49,6 +49,9 @@ void test(const Mesh& pmesh)
       continue;
     else
     {
+      double face_area = PMP::area(face(h, pmesh), pmesh);
+      std::cout << "face area = " << face_area << std::endl;
+ 
       patch.push_back(face(h, pmesh));
       patch.push_back(face(opposite(h, pmesh), pmesh));
       patch.push_back(face(opposite(next(h, pmesh), pmesh), pmesh));
@@ -59,6 +62,8 @@ void test(const Mesh& pmesh)
   double patch_area = PMP::area(patch, pmesh);
   std::cout << "patch area = " << patch_area << std::endl;
 
+  double mesh_area = PMP::area(pmesh);
+  std::cout << "mesh area = " << mesh_area << std::endl;
 }
 
 void test_polyhedron(const char* filename)