Merge branch 'featureMeshConversion' into 'master'

Feature mesh conversion

implements a cast from polyMesh to Mesh and vice versa using  static_cast<Mesh>(polymeshInstance) or static_cast<PolyMesh>(trimeshInstance)
as mentioned in #23 .

Copy constructors for respective mesh types were added as well as a function to copy all properties from one mesh to another.
Unittest for mesh conversions were added checking the number of vertices / faces as well as custom double vertex properties and edge properties.

Note: The used triangulation only works for convex polygons, it should be replaced by the earclipping triangulation mentioned in #33

See merge request !110

Doc/changelog.docu

@@ -10,6 +10,7 @@
 
 <b>Core</b>
 <ul>
+<li>Implemented a cast from polyMesh to Mesh and vice versa using static_cast(polymeshInstance) or static_cast(trimeshInstance)</li>
 <li>make all negative handles invalid, not just -1</li>
 <li>Several warnings fixed (Including the checked iterators)</li>
 </ul>

src/OpenMesh/Core/Mesh/BaseKernel.hh

@@ -583,6 +583,18 @@ public:
 
   }
 
+  /**
+   * @brief copy_all_kernel_properties uses the = operator to copy all properties from a given other BaseKernel.
+   * @param _other Another BaseKernel, to copy the properties from.
+   */
+  void copy_all_kernel_properties(const BaseKernel & _other)
+  {
+    this->vprops_ = _other.vprops_;
+    this->eprops_ = _other.eprops_;
+    this->hprops_ = _other.hprops_;
+    this->fprops_ = _other.fprops_;
+  }
+
 protected: //------------------------------------------------- low-level access
 
 public: // used by non-native kernel and MeshIO, should be protected

src/OpenMesh/Core/Mesh/PolyMeshT.hh

@@ -186,6 +186,8 @@ public:
 
   // --- constructor/destructor
   PolyMeshT() {}
+  template<typename T>
+  explicit PolyMeshT(const T& t) : Kernel(t) {}
   virtual ~PolyMeshT() {}
 
   /** Uses default copy and assignment operator.

src/OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh

@@ -74,7 +74,8 @@
 
 namespace OpenMesh {
 
-
+template<class Traits>
+class TriMesh_ArrayKernelT;
 //== CLASS DEFINITION =========================================================
 
 /// Helper class to build a PolyMesh-type
@@ -97,7 +98,18 @@ struct PolyMesh_ArrayKernel_GeneratorT
 template <class Traits = DefaultTraits>
 class PolyMesh_ArrayKernelT
   : public PolyMesh_ArrayKernel_GeneratorT<Traits>::Mesh
-{};
+{
+public:
+  PolyMesh_ArrayKernelT() {}
+  template<class OtherTraits>
+   PolyMesh_ArrayKernelT( const TriMesh_ArrayKernelT<OtherTraits> & t)
+  {
+     //assign the connectivity (add vertices)
+     this->assign(t);
+     //copy properties from triMesh
+     this->copy_all_kernel_properties(t);
+  }
+};
 
 
 //=============================================================================

src/OpenMesh/Core/Mesh/TriMeshT.hh

@@ -169,6 +169,10 @@ public:
 
   /// Default constructor
   TriMeshT() : PolyMesh() {}
+  explicit TriMeshT(PolyMesh rhs) : PolyMesh((rhs.triangulate(), rhs))
+  {
+  }
+
   /// Destructor
   virtual ~TriMeshT() {}
 

src/OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh

@@ -74,7 +74,8 @@
 
 namespace OpenMesh {
 
-
+template<class Traits>
+class PolyMesh_ArrayKernelT;
 //== CLASS DEFINITION =========================================================
 
 
@@ -97,7 +98,18 @@ struct TriMesh_ArrayKernel_GeneratorT
 template <class Traits = DefaultTraits>
 class TriMesh_ArrayKernelT
   : public TriMesh_ArrayKernel_GeneratorT<Traits>::Mesh
-{};
+{
+public:
+  TriMesh_ArrayKernelT() {}
+  template<class OtherTraits>
+   TriMesh_ArrayKernelT( const PolyMesh_ArrayKernelT<OtherTraits> & t)
+  {
+     //assign the connectivity (add vertices)
+     this->assign(t);
+     //copy properties from polyMesh
+     this->copy_all_kernel_properties(t);
+  }
+};
 
 
 //=============================================================================