meshkernel.hh

penMesh is a generic and efficient data structure for representing and manipulating polygonal meshes

//=============================================================================
//                                                                            
//                               OpenMesh                                     
//      Copyright (C) 2001-2005 by Computer Graphics Group, RWTH Aachen       
//                           www.openmesh.org                                 
//                                                                            
//-----------------------------------------------------------------------------
//                                                                            
//                                License                                     
//                                                                            
//   This library is free software; you can redistribute it and/or modify it 
//   under the terms of the GNU Library General Public License as published  
//   by the Free Software Foundation, version 2.                             
//                                                                             
//   This library is distributed in the hope that it will be useful, but       
//   WITHOUT ANY WARRANTY; without even the implied warranty of                
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         
//   Library General Public License for more details.                          
//                                                                            
//   You should have received a copy of the GNU Library General Public         
//   License along with this library; if not, write to the Free Software       
//   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                 
//                                                                            
//-----------------------------------------------------------------------------
//                                                                            
//   $Revision: 1.2 $
//   $Date: 2005-12-21 14:05:27 $
//                                                                            
//=============================================================================


//=============================================================================
//
//  Kernel Concept
//
//=============================================================================


#error this file is for documentation purposes only


//== NAMESPACES ===============================================================


namespace OpenMesh {
namespace Concepts {


//== CLASS DEFINITION =========================================================


/** \ingroup mesh_concepts_group
    This class describes the minimum interface a mesh kernel 
    has to implement (because the resulting mesh will rely on
    this interface).

    This is the template class the actually holds the mesh kernel
    implementation. All functions marked as internal should only be used
    by the mesh class (that inherits the kernel). The mesh may then
    provide wrapper functions that provide the same functionality.

    \todo Check, if the member list is complete.
*/
template <class FinalMeshItems> class KernelT
{
public:
  
  /// \name Mesh Items
  //@{

  /// Derive this type from the FinalMeshItems
  typedef typename FinalMeshItems::Vertex             Vertex;
  typedef typename FinalMeshItems::Halfedge           Halfedge;
  typedef typename FinalMeshItems::Edge               Edge;
  typedef typename FinalMeshItems::Face               Face;
  typedef typename FinalMeshItems::Point              Point;
  typedef typename FinalMeshItems::Scalar             Scalar;
  typedef typename FinalMeshItems::Normal             Normal;
  typedef typename FinalMeshItems::Color              Color;
  typedef typename FinalMeshItems::TexCoord           TexCoord;
  typedef typename FinalMeshItems::VertexHandle       VertexHandle;    
  typedef typename FinalMeshItems::HalfedgeHandle     HalfedgeHandle;  
  typedef typename FinalMeshItems::EdgeHandle         EdgeHandle;      
  typedef typename FinalMeshItems::FaceHandle         FaceHandle;      

  //@}


  /// \name Kernel Iterators
  //@{
  /// This type depends on the container type in use.
  typedef SomeIterator KernelVertexIter;
  typedef SomeIterator KernelConstVertexIter;
  typedef SomeIterator KernelEdgeIter;
  typedef SomeIterator KernelConstEdgeIter;
  typedef SomeIterator KernelFaceIter;
  typedef SomeIterator KernelConstFaceIter;
  //@}

  /// \name Constructor/Destructor
  //@{
  /// Default constructor
  KernelT() {}

  /// Destructor
  ~KernelT();
  //@}

  /// Assignment operator
  KernelT& operator=(const KernelT& _rhs);


  /** Reserve memory for vertices, edges, faces.  
   *
   *  Reserve memory for the mesh items vertices, edges, faces.  Use
   *  this method if you can estimate the memory consumption, for
   *  instance in algorithm expanding the mesh. Depending on the
   *  underlying array type you might be better of using this method,
   *  then letting the array type decide when to increase the
   *  capacity. For instance the STL vector class \c std::vector (used
   *  in the supplied ArrayKernelT) doubles the capacity if it is
   *  exhausted. This might lead to an memory allocation exception,
   *  though an smaller increment would be enough.
   */
  void reserve( unsigned int _n_vertices,
		unsigned int _n_edges,
		unsigned int _n_faces );
  

  /// \name Handle -> Item. 
  //@{
  /// Translate handle to item (see also OpenMesh::PolyMeshT::deref())
  const Vertex& vertex(VertexHandle _h) const { return deref(_h); }
  Vertex& vertex(VertexHandle _h) { return deref(_h); }
  const Halfedge& halfedge(HalfedgeHandle _h) const { return deref(_h); }
  Halfedge& halfedge(HalfedgeHandle _h) { return deref(_h); }
  const Edge& edge(EdgeHandle _h) const { return deref(_h); }
  Edge& edge(EdgeHandle _h) { return deref(_h); }
  const Face& face(FaceHandle _h) const { return deref(_h); }
  Face& face(FaceHandle _h) { return deref(_h); }
  //@}


  /// \name Item -> Handle
  //@{
  /// Translate item to handle
  VertexHandle handle(const Vertex& _v) const;
  HalfedgeHandle handle(const Halfedge& _he) const;
  EdgeHandle handle(const Edge& _e) const;
  FaceHandle handle(const Face& _f) const;
  //@}


  /// \name Get the i'th item
  //@{
  /// Get the i'th item
  VertexHandle   vertex_handle(unsigned int _i) const;
  HalfedgeHandle halfedge_handle(unsigned int _i) const;
  EdgeHandle     edge_handle(unsigned int _i) const;
  FaceHandle     face_handle(unsigned int _i) const;
  //@}


  /// \name Delete items
  //@{
  /// Delete all items, i.e. clear all item containers.
  void clear();
  /** Remove all items that are marked as deleted from the
      corresponding containers.
      \note Needs the Attributes::Status attribute
      \note This function may not be implemented for all kernels.
  */
  void garbage_collection();

  /** Remove the last vertex imidiately, i.e. call pop_back() for the
      VertexContainer. 
  */
  void remove_last_vertex() { vertices_.pop_back(); }
  /** Remove the last edge imidiately, i.e. call pop_back() for the
      EdgeContainer. Used e.g. by the add_face() method of PolyMeshT
  */
  void remove_last_edge()   { edges_.pop_back();    }
  /** Remove the last face imidiately, i.e. call pop_back() for the
      FaceContainer. Used e.g. by the add_face() method of PolyMeshT
  */
  void remove_last_face()   { faces_.pop_back();    }

  //@}




  /// \name Number of elements
  //@{
  /// Returns number of vertices
  unsigned int n_vertices() const;
  /// Returns number of halfedges (should be 2*n_edges())
  unsigned int n_halfedges() const;
  /// Returns number of edges
  unsigned int n_edges() const;
  /// Returns number of faces
  unsigned int n_faces() const;
  /// Is the vertex container empty?
  bool vertices_empty() const;
  /// Is the halfedge container empty (should be the same as edges_empty()).
  bool halfedges_empty() const;
  /// Is the edge container empty?
  bool edges_empty() const;
  /// Is the face container empty?
  bool faces_empty() const;
  //@}



  /// \name Vertex connectivity
  //@{
  /// Get an outgoing halfedge of a given vertex
  HalfedgeHandle halfedge_handle(VertexHandle _vh) const;
  /// Set the outgoing halfedge handle of a given vertex
  void set_halfedge_handle(VertexHandle _vh, HalfedgeHandle _heh);
  /// Get the coordinate of a vertex
  const Point& point(VertexHandle _vh) const;
  /// Get the coordinate of a vertex
  const Point& point(const Vertex& _v) const;
  /// Set the coordinate of a vertex
  void set_point(VertexHandle _vh, const Point& _p);
  /// Set the coordinate of a vertex
  void set_point(Vertex& _v, const Point& _p);
  //@}
 



  /// \name Halfedge connectivity
  //@{
  /// Get the vertex the halfedge points to
  VertexHandle to_vertex_handle(HalfedgeHandle _heh) const;
  /** Get the vertex the halfedge starts from (implemented as to-handle
      of the opposite halfedge, provided for convenience) */
  VertexHandle from_vertex_handle(HalfedgeHandle _heh) const;
  /// Set the to-vertex-handle of the halfedge
  void set_vertex_handle(HalfedgeHandle _heh, VertexHandle _vh);
  /** Get the face the halfedge belongs to.
      \note The handle is invalid if the halfedge is a boundary halfedge */
  FaceHandle face_handle(HalfedgeHandle _heh) const;
  /// Set the face the halfedge belongs to
  void set_face_handle(HalfedgeHandle _heh, FaceHandle _fh);
  /// Get the next halfedge handle
  HalfedgeHandle next_halfedge_handle(HalfedgeHandle _heh) const;
  /** Set the next halfedge handle.  \note If the previous halfedge is
      also stored (see OpenMesh::Attributes::PrevHalfedge) then this
      method also has to set this link) */
  void set_next_halfedge_handle(HalfedgeHandle _heh, HalfedgeHandle _nheh);
  /** Get the previous halfedge of the given halfedge. The
      implementation should take care of an existing
      OpenMesh::Attributes::PrevHalfedge attribute. */