Add SMS::Envelope_filter

Surface_mesh_simplification/doc/Surface_mesh_simplification/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Envelope_filter.h

@@ -0,0 +1,59 @@
+
+namespace CGAL {
+namespace Surface_mesh_simplification {
+
+/*!
+\ingroup PkgSurfaceMeshSimplificationRef
+
+The class `Envelope_filter` is a model for the `GetFilter` concept.
+It rejects the placement if the nested filter rejects it, or
+if any triangle in the profile is not inside the polyhedral envelope, in this order.
+
+
+\tparam Get_filter_ must be a model of the concept `GetFilter`.  It defaults to a class that does
+not filter any placement.
+
+\cgalModels `GetFilter`
+
+\sa `Envelope`
+
+*/
+template <typename GeomTraits,typename GetFilter_>
+class Envelope_filter {
+public:
+
+  /// The number type
+  typedef typename Geom_traits::FT    FT;
+
+  /// \name Creation
+  /// @{
+
+  /*!
+  %Default constructor
+  */
+  Envelope_filter();
+
+  /*!
+  Constructor
+
+  \param get_filter is the filter that will be filtered.
+  */
+  Envelope_filter(const FT& dist, const GetFilter_& get_filter);
+
+  /// @}
+
+  /// \name Operations
+  /// @{
+
+  /*!
+  Returns the placement, if it does not get filtered by the wrapped filter,
+  and if all triangles in the profile are inside the polyhedral envelope.
+  */
+  boost::optional<typename Edge_profile::Point> operator()(const Edge_profile& profile,
+                                                           boost::optional<typename Profile::Point> op) const;
+
+  /// @}
+
+}; /* end Surface_mesh_simplification::Envelope_filter */
+} // namespace Surface_Mesh_Simplification
+} // namespace CGAL