allow PropertyManagers to be used in smart ranges

src/OpenMesh/Core/Mesh/SmartRange.hh

@@ -59,7 +59,7 @@ struct SmartRangeT
   // TODO: Someone with better c++ knowledge may improve the code below.
 
   template <typename Functor>
-  auto sum(Functor f) -> decltype (f(std::declval<HandleT>())+f(std::declval<HandleT>()))
+  auto sum(Functor&& f) -> decltype (f(std::declval<HandleT>())+f(std::declval<HandleT>()))
   {
     auto range = static_cast<const RangeT*>(this);
     auto begin = range->begin();
@@ -73,6 +73,27 @@ struct SmartRangeT
     return sum;
   }
 
+  template <typename Functor>
+  auto avg(Functor&& f) -> decltype (1.0 * (f(std::declval<HandleT>())+f(std::declval<HandleT>())))
+  {
+    auto range = static_cast<const RangeT*>(this);
+    auto begin = range->begin();
+    auto end   = range->end();
+    assert(begin != end);
+    decltype (f(*begin) + f(*begin)) sum = f(*begin);
+    auto it = begin;
+    ++it;
+    int n_elements = 1;
+    for (; it != end; ++it)
+    {
+      sum += f(*it);
+      ++n_elements;
+    }
+    return (1.0 / n_elements) * sum;
+  }
+
+
+
 };
 
 

src/OpenMesh/Core/Utils/PropertyManager.hh

@@ -380,6 +380,30 @@ class PropertyManager {
             return mesh_->property(prop_, handle);
         }
 
+        /**
+         * Enables convenient access to the encapsulated property.
+         *
+         * For a usage example see this class' documentation.
+         *
+         * @param handle A handle of the appropriate handle type. (I.e. \p VertexHandle for \p VPropHandleT, etc.)
+         */
+        template<typename HandleType>
+        inline typename PROPTYPE::reference operator() (const HandleType &handle) {
+            return mesh_->property(prop_, handle);
+        }
+
+        /**
+         * Enables convenient access to the encapsulated property.
+         *
+         * For a usage example see this class' documentation.
+         *
+         * @param handle A handle of the appropriate handle type. (I.e. \p VertexHandle for \p VPropHandleT, etc.)
+         */
+        template<typename HandleType>
+        inline typename PROPTYPE::const_reference operator() (const HandleType &handle) const {
+            return mesh_->property(prop_, handle);
+        }
+
         /**
          * Conveniently set the property for an entire range of values.
          *

src/Unittests/unittests_smart_ranges.cc

@@ -2,6 +2,7 @@
 #include <Unittests/unittests_common.hh>
 
 #include <OpenMesh/Core/Mesh/SmartHandles.hh>
+#include <OpenMesh/Core/Utils/PropertyManager.hh>
 
 #include <iostream>
 #include <chrono>
@@ -192,5 +193,25 @@ TEST_F(OpenMeshSmartRanges, Sum)
 }
 
 
+/* Test if Property Manager can be used in smart ranges
+ */
+TEST_F(OpenMeshSmartRanges, PropertyManagerAsFunctor)
+{
+  auto myPos = OpenMesh::makeTemporaryProperty<OpenMesh::VertexHandle, Mesh::Point>(mesh_);
+
+  for (auto vh : mesh_.vertices())
+    myPos(vh) = mesh_.point(vh);
+
+  Mesh::Point cog(0,0,0);
+  for (auto vh : mesh_.vertices())
+    cog += mesh_.point(vh);
+  cog /= mesh_.n_vertices();
+
+  auto cog2 = mesh_.vertices().avg(myPos);
+
+  EXPECT_LT(norm(cog - cog2), 0.00001) << "Computed center of gravities are significantly different.";
+}
+
+
 
 }