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

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// 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/Sweep_line_empty_visitor.h $
// $Id: Sweep_line_empty_visitor.h 50366 2009-07-05 12:56:48Z efif $
// 
//
// Author(s)     : Baruch Zukerman <baruchzu@post.tau.ac.il>

#ifndef CGAL_SWEEP_LINE_EMPTY_VISITOR_H
#define CGAL_SWEEP_LINE_EMPTY_VISITOR_H

#include <CGAL/Basic_sweep_line_2.h>
#include <CGAL/Sweep_line_2/Sweep_line_event.h>
#include <CGAL/Sweep_line_2/Sweep_line_subcurve.h>

CGAL_BEGIN_NAMESPACE

template <class Traits_,
          class Subcurve_  =  Sweep_line_subcurve<Traits_>,
          typename Event_  =  Sweep_line_event<Traits_, Subcurve_>,
          class Allocator_ =  CGAL_ALLOCATOR(int)>
class Sweep_line_empty_visitor
{
public:

  typedef Traits_                                    Traits_2;
  typedef Subcurve_                                  Subcurve;
  typedef Event_                                     Event;
  typedef Allocator_                                 Allocator;

  typedef typename Traits_2::X_monotone_curve_2      X_monotone_curve_2;
  typedef typename Traits_2::Point_2                 Point_2; 

  typedef Sweep_line_empty_visitor<Traits_2,
                                   Subcurve,
                                   Event,
                                   Allocator>        Self;

private:

  // we want to hide the Sweep_line type
  typedef Basic_sweep_line_2<Traits_2,
                             Self,
                             Subcurve,
                             Event,
                             Allocator>              Sweep_line;
  
  typedef typename Sweep_line::Status_line_iterator  Base_status_line_iter;

public:
  
  class Status_line_iterator : public Base_status_line_iter
  {
  public:

    typedef Subcurve*                                        value_type;
    typedef value_type&                                      reference;
    typedef value_type*                                      pointer;
    typedef typename Base_status_line_iter::difference_type  difference_type;
    typedef typename Base_status_line_iter::iterator_category
                                                             iterator_category;
    Status_line_iterator()
    {}

    Status_line_iterator (Base_status_line_iter iter) :
      Base_status_line_iter (iter)
    {}
    
    // Overriden operator*
    reference operator* ()
    {
      return (reinterpret_cast<reference>
              (((Base_status_line_iter*)this)->operator*()));
    }

    // Overriden operator->
    pointer operator-> ()
    {
      return (reinterpret_cast<pointer>
              (Base_status_line_iter::operator->()));
    }
  };


  typedef typename Event::Subcurve_iterator          Event_subcurve_iterator;
  typedef typename Event::Subcurve_reverse_iterator
    Event_subcurve_reverse_iterator;

protected:

  // Data members:
  void*    m_sweep_line;           // The sweep-line object.

public:

  Sweep_line_empty_visitor () :
    m_sweep_line (NULL)
  {}

  void attach (void* sl)
  {
    m_sweep_line = sl;
  }

  virtual ~Sweep_line_empty_visitor()
  {}

  void before_handle_event (Event* /* event */)
  {}

  bool after_handle_event (Event* /* event */,
                           Status_line_iterator /* iter */,
                           bool /* flag */)
  {
    return (true);
  }

  void add_subcurve (X_monotone_curve_2 /* cv */,
                     Subcurve* /* sc */)
  {}

  void before_sweep()
  {}

  void after_sweep()
  {}

  void update_event (Event* /* e */,
                     const Point_2& /* end_point */,
                     const X_monotone_curve_2& /* cv */,
                     Arr_curve_end /* cv_end */,
                     bool /* is_new */)
  {}

  void update_event (Event* /* e */,
                     const X_monotone_curve_2& /* cv */,
                     Arr_curve_end /* cv_end */,
                     bool /* is_new */)
  {}

  void update_event (Event* /* e */,
                     Subcurve* /* sc1 */,
                     Subcurve* /* sc2 */,
                     bool /* is_new */)
  {}

  void update_event (Event* /* e */,
                     Subcurve* /* sc1 */)
  {}

  void update_event (Event* /* e */,
                     const Point_2& /* pt */,
                     bool /* is_new */)
  {}

  /* Found overlap */
  void found_overlap (Subcurve* /* sc1 */,
                      Subcurve* /* sc2 */,
                      Subcurve* /* ov_sc */)
  {}

  Status_line_iterator status_line_begin()
  {
    return (_sweep_line()->status_line_begin());
  }

  Status_line_iterator status_line_end()
  {
    return (_sweep_line()->status_line_end());
  }

  Status_line_iterator status_line_position (Subcurve *sc)
  {
    return (sc->hint());
  }

  unsigned status_line_size() const
  {
    return (_sweep_line()->status_line_size());
  }

  bool is_status_line_empty() const
  {
    return (_sweep_line()->is_status_line_empty());
  }

  void deallocate_event (Event* e)
  {
    _sweep_line()->deallocate_event(e);
  }

  void stop_sweep()
  {
    _sweep_line()->stop_sweep();
  }

  void* sweep_line ()
  {
    return (m_sweep_line);
  }

  Event* current_event()
  {
    return (_sweep_line()->current_event());
  }

  const Traits_2 * traits ()
  {
    return (_sweep_line()->traits());
  }

private:

  Sweep_line* _sweep_line ()
  {
    return (reinterpret_cast<Sweep_line*>(m_sweep_line));
  }
};

CGAL_END_NAMESPACE

#endif