SPAR/AIModule/BWTA/vendors/CGAL/CGAL/Arr_walk_along_line_point_location.h

Go to the documentation of this file.

// Copyright (c) 2005  Tel-Aviv University (Israel).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/CGAL-3.5-branch/Arrangement_on_surface_2/include/CGAL/Arr_walk_along_line_point_location.h $
// $Id: Arr_walk_along_line_point_location.h 35622 2006-12-25 08:56:47Z wein $
// 
//
// Author(s)     : Ron Wein   <wein@post.tau.ac.il>
//                 (based on old version by Oren Nechushtan
//                                      and Iddo Hanniel)
#ifndef CGAL_ARR_WALK_ALONG_LINE_POINT_LOCATION_H
#define CGAL_ARR_WALK_ALONG_LINE_POINT_LOCATION_H

#include <CGAL/Arrangement_2/Arr_traits_adaptor_2.h>

CGAL_BEGIN_NAMESPACE

template <class Arrangement_>
class Arr_walk_along_line_point_location
{
public:

  typedef Arrangement_                                   Arrangement_2;
  typedef typename Arrangement_2::Geometry_traits_2      Geometry_traits_2;
  typedef typename Arrangement_2::Topology_traits        Topology_traits;

  typedef typename Arrangement_2::Vertex_const_handle    Vertex_const_handle;
  typedef typename Arrangement_2::Halfedge_const_handle  Halfedge_const_handle;
  typedef typename Arrangement_2::Face_const_handle      Face_const_handle;

  typedef typename Geometry_traits_2::Point_2            Point_2;
  typedef typename Geometry_traits_2::X_monotone_curve_2 X_monotone_curve_2;

protected:

  typedef Arr_traits_basic_adaptor_2<Geometry_traits_2>  Traits_adaptor_2;
  typedef typename Arrangement_2::Ccb_halfedge_const_circulator
                                             Ccb_halfedge_const_circulator;
  typedef typename Arrangement_2::Inner_ccb_const_iterator
                                             Inner_ccb_const_iterator;
  typedef typename Arrangement_2::Isolated_vertex_const_iterator
                                             Isolated_vertex_const_iterator;

  // Data members:
  const Arrangement_2     *p_arr;        // The associated arrangement.  
  const Traits_adaptor_2  *geom_traits;  // Its associated geometry traits.
  const Topology_traits   *top_traits;   // Its associated topology traits.

public:

  Arr_walk_along_line_point_location () : 
    p_arr (NULL),
    geom_traits (NULL),
    top_traits (NULL)
  {}
        
  Arr_walk_along_line_point_location (const Arrangement_2& arr) :
    p_arr (&arr)
  {
    geom_traits =
      static_cast<const Traits_adaptor_2*> (p_arr->geometry_traits());
    top_traits = p_arr->topology_traits();
  }

  void attach (const Arrangement_2& arr) 
  {
    p_arr = &arr;
    geom_traits =
      static_cast<const Traits_adaptor_2*> (p_arr->geometry_traits());
    top_traits = p_arr->topology_traits();
  }

  void detach ()
  {
    p_arr = NULL;
    geom_traits = NULL;
    top_traits = NULL;
  }
 
  Object locate (const Point_2& p) const;

  Object ray_shoot_up (const Point_2& p) const
  {
    return (_vertical_ray_shoot (p, true));
  }

  Object ray_shoot_down (const Point_2& p) const
  {
    return (_vertical_ray_shoot (p, false));
  }

protected:

  Object _vertical_ray_shoot (const Point_2& p, bool shoot_up) const;

  bool _is_in_connected_component (const Point_2& p,
                                   Ccb_halfedge_const_circulator circ,
                                   bool shoot_up,
                                   bool inclusive,
                                   Halfedge_const_handle& closest_he,
                                   bool& is_on_edge,
                                   bool& closest_to_target) const;

  Halfedge_const_handle _first_around_vertex (Vertex_const_handle v,
                                              bool shoot_up) const;
};

CGAL_END_NAMESPACE

// The member-function definitions can be found under:
#include <CGAL/Arr_point_location/Arr_walk_along_line_pl_impl.h>

#endif