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// Copyright (c) 1997 Utrecht University (The Netherlands),
// ETH Zurich (Switzerland), Freie Universitaet Berlin (Germany),
// INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
// (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
// and Tel-Aviv University (Israel). All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; version 2.1 of the License.
// See the file LICENSE.LGPL 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-3.2-branch/Polygon/include/CGAL/Polygon_2_algorithms.h $
// $Id: Polygon_2_algorithms.h 28567 2006-02-16 14:30:13Z lsaboret $
//
//
// Author(s) : Wieger Wesselink <wieger@cs.ruu.nl>
#ifndef CGAL_POLYGON_2_ALGORITHMS_H
#define CGAL_POLYGON_2_ALGORITHMS_H
#include <CGAL/basic.h>
#include <CGAL/enum.h>
#include <CGAL/Bbox_2.h>
#include <CGAL/polygon_assertions.h>
CGAL_BEGIN_NAMESPACE
//-----------------------------------------------------------------------//
// algorithms for sequences of 2D points
//-----------------------------------------------------------------------//
template <class ForwardIterator, class Traits>
ForwardIterator left_vertex_2(ForwardIterator first,
ForwardIterator last,
const Traits& traits);
template <class ForwardIterator, class Traits>
ForwardIterator right_vertex_2(ForwardIterator first,
ForwardIterator last,
const Traits& traits);
template <class ForwardIterator, class Traits>
ForwardIterator top_vertex_2(ForwardIterator first,
ForwardIterator last,
const Traits& traits);
template <class ForwardIterator, class Traits>
ForwardIterator bottom_vertex_2(ForwardIterator first,
ForwardIterator last,
const Traits& traits);
template <class InputIterator, class Traits>
Bbox_2 bbox_2(InputIterator first,
InputIterator last,
const Traits& traits);
template <class ForwardIterator, class Traits>
void
area_2( ForwardIterator first, ForwardIterator last,
typename Traits::FT &result,
const Traits& traits)
{
typedef typename Traits::FT FT;
result = FT(0);
// check if the polygon is empty
if (first == last) return;
ForwardIterator second = first; ++second;
// check if the polygon has only one point
if (second == last) return;
typename Traits::Compute_area_2 compute_area_2 =
traits.compute_area_2_object();
ForwardIterator third = second;
while (++third != last) {
result = result + compute_area_2(*first, *second, *third);
second = third;
}
}
template <class ForwardIterator, class Traits>
typename Traits::FT
polygon_area_2( ForwardIterator first, ForwardIterator last,
const Traits& traits)
{
typedef typename Traits::FT FT;
FT result = FT(0);
// check if the polygon is empty
if (first == last) return result;
ForwardIterator second = first; ++second;
// check if the polygon has only one point
if (second == last) return result;
typename Traits::Compute_area_2 compute_area_2 =
traits.compute_area_2_object();
ForwardIterator third = second;
while (++third != last) {
result = result + compute_area_2(*first, *second, *third);
second = third;
}
return result;
}
template <class ForwardIterator, class Traits>
bool is_convex_2(ForwardIterator first,
ForwardIterator last,
const Traits& traits);
template <class ForwardIterator, class Traits>
bool is_simple_2(ForwardIterator first,
ForwardIterator last,
const Traits& traits);
// In the following two functions we would like to use Traits::Point_2 instead
// of Point, but this is not allowed by g++ 2.7.2.
template <class ForwardIterator, class Point, class Traits>
Oriented_side oriented_side_2(ForwardIterator first,
ForwardIterator last,
const Point& point,
const Traits& traits);
template <class ForwardIterator, class Point, class Traits>
Bounded_side bounded_side_2(ForwardIterator first,
ForwardIterator last,
const Point& point,
const Traits& traits);
template <class ForwardIterator, class Traits>
Orientation orientation_2(ForwardIterator first,
ForwardIterator last,
const Traits& traits);
//-----------------------------------------------------------------------//
// implementation
//-----------------------------------------------------------------------//
#ifdef CGAL_REP_CLASS_DEFINED
template <class ForwardIterator>
inline
ForwardIterator left_vertex_2(ForwardIterator first,
ForwardIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return left_vertex_2(first, last, K());
}
template <class ForwardIterator>
inline
ForwardIterator right_vertex_2(ForwardIterator first,
ForwardIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return right_vertex_2(first, last, K());
}
template <class ForwardIterator>
inline
ForwardIterator top_vertex_2(ForwardIterator first,
ForwardIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return top_vertex_2(first, last, K());
}
template <class ForwardIterator>
inline
ForwardIterator bottom_vertex_2(ForwardIterator first,
ForwardIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return bottom_vertex_2(first, last, K());
}
template <class InputIterator>
inline
Bbox_2 bbox_2(InputIterator first,
InputIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<InputIterator>::value_type>::Kernel K;
return bbox_2(first, last, K());
}
template <class ForwardIterator, class Numbertype>
inline
void area_2(ForwardIterator first,
ForwardIterator last,
Numbertype& result)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
area_2(first, last, result, K());
}
template <class ForwardIterator>
inline
bool is_convex_2(ForwardIterator first,
ForwardIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return is_convex_2(first, last, K());
}
template <class ForwardIterator>
inline
bool is_simple_2(ForwardIterator first,
ForwardIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return is_simple_2(first, last, K());
}
template <class ForwardIterator>
inline
Oriented_side oriented_side_2(
ForwardIterator first,
ForwardIterator last,
const typename std::iterator_traits<ForwardIterator>::value_type& point)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return oriented_side_2(first, last, point, K());
}
template <class ForwardIterator>
inline
Bounded_side bounded_side_2(
ForwardIterator first,
ForwardIterator last,
const typename std::iterator_traits<ForwardIterator>::value_type& point)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return bounded_side_2(first, last, point, K());
}
template <class ForwardIterator>
inline
Orientation orientation_2(ForwardIterator first,
ForwardIterator last)
{
typedef typename Kernel_traits<
typename std::iterator_traits<ForwardIterator>::value_type>::Kernel K;
return orientation_2(first, last, K());
}
#endif // CGAL_REP_CLASS_DEFINED
CGAL_END_NAMESPACE
#ifdef CGAL_CFG_NO_AUTOMATIC_TEMPLATE_INCLUSION
#include <CGAL/Polygon_2_algorithms.C>
#endif // CGAL_CFG_NO_AUTOMATIC_TEMPLATE_INCLUSION
#endif // CGAL_POLYGON_2_ALGORITHMS_H
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