SPAR/AIModule/BWTA/vendors/CGAL/CGAL/Arr_batched_point_location.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/Arr_batched_point_location.h $
// $Id: Arr_batched_point_location.h 50366 2009-07-05 12:56:48Z efif $
//
// Author(s)     : Baruch Zukerman <baruchzu@post.tau.ac.il>
//                 Ron Wein <wein@post.tau.ac.il>
//                 Efi Fogel <efif@post.tau.ac.il>

#ifndef CGAL_ARR_BATCHED_POINT_LOCATION_H
#define CGAL_ARR_BATCHED_POINT_LOCATION_H

#include <CGAL/Arrangement_on_surface_2.h>
#include <CGAL/Basic_sweep_line_2.h>

#include <vector>
#include <boost/mpl/if.hpp>
#include <boost/type_traits.hpp>

CGAL_BEGIN_NAMESPACE

template<class GeomTraits, class TopTraits,
         class PointsIterator, class OutputIterator> 
OutputIterator locate
    (const Arrangement_on_surface_2<GeomTraits, TopTraits>& arr,
     PointsIterator points_begin, PointsIterator points_end,
     OutputIterator oi)
{
  // Arrangement types:
  typedef Arrangement_on_surface_2<GeomTraits, TopTraits>  Arr;
  typedef typename TopTraits::template
          Sweep_line_bacthed_point_location_visitor<OutputIterator>
                                                           Bpl_visitor;

  typedef typename Arr::Halfedge_const_handle          Halfedge_const_handle;
  typedef typename Arr::Vertex_const_iterator          Vertex_const_iterator;
  typedef typename Arr::Edge_const_iterator            Edge_const_iterator;
  typedef typename Arr::Vertex_const_handle            Vertex_const_handle;
  typedef typename Arr::Halfedge_const_handle          Halfedge_const_handle;

  typedef typename Bpl_visitor::Traits_2               Bpl_traits_2;
  typedef typename Bpl_traits_2::X_monotone_curve_2    Bpl_x_monotone_curve_2;
  typedef typename Bpl_traits_2::Point_2               Bpl_point_2;

  // Go over all arrangement edges and collect their associated x-monotone
  // curves. To each curve we attach a halfedge handle going from right to
  // left.
  std::vector<Bpl_x_monotone_curve_2>  xcurves_vec (arr.number_of_edges());
  Edge_const_iterator                  eit;
  Halfedge_const_handle                he;
  unsigned int                         i = 0;

  for (eit = arr.edges_begin(); eit != arr.edges_end(); ++eit, ++i) 
  {
    // Associate each x-monotone curve with the halfedge that represent it
    // that is directed from right to left.
    if (eit->direction() == ARR_RIGHT_TO_LEFT)
      he = eit;
    else
      he = eit->twin();

    xcurves_vec[i] = Bpl_x_monotone_curve_2 (eit->curve(), he);
  }

  // Go over all isolated vertices and collect their points. To each point
  // we attach its vertex handle.
  std::vector<Bpl_point_2>    iso_pts_vec (arr.number_of_isolated_vertices());
  Vertex_const_iterator       vit;
  Vertex_const_handle         iso_v;

  i = 0;
  for (vit = arr.vertices_begin(); vit != arr.vertices_end(); ++vit, ++i)
  {
    if (vit->is_isolated())
    {
      iso_v = vit;
      iso_pts_vec[i] = Bpl_point_2 (vit->point(), iso_v);
    }
  }
    
  // Obtain a extended traits-class object.
  GeomTraits    *geom_traits = const_cast<GeomTraits*> (arr.geometry_traits());

  /* We would like to avoid copy construction of the geometry traits class.
   * Copy construction is undesired, because it may results with data
   * duplication or even data loss.
   *
   * If the type Bpl_traits_2 is the same as the type
   * GeomTraits, use a reference to GeomTraits to avoid constructing a new one.
   * Otherwise, instantiate a local variable of the former and provide
   * the later as a single parameter to the constructor.
   * 
   * Use the form 'A a(*b);' and not ''A a = b;' to handle the case where A has
   * only an implicit constructor, (which takes *b as a parameter).
   */
  typename boost::mpl::if_<boost::is_same<GeomTraits, Bpl_traits_2>,
                           const Bpl_traits_2&, Bpl_traits_2>::type
    ex_traits(*geom_traits);

  // Define the sweep-line visitor and perform the sweep.
  Bpl_visitor   visitor (&arr, &oi);
  Basic_sweep_line_2<typename Bpl_visitor::Traits_2,
                     Bpl_visitor,
                     typename Bpl_visitor::Subcurve,
                     typename Bpl_visitor::Event>
    sweep_line (&ex_traits, &visitor);

  sweep_line.sweep (xcurves_vec.begin(), xcurves_vec.end(), // Curves.
                    iso_pts_vec.begin(), iso_pts_vec.end(), // Action points.
                    points_begin, points_end);              // Query points.

  return (oi);
}

CGAL_END_NAMESPACE

#endif