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// Copyright (c) 1998 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/Generator/include/CGAL/random_convex_set_2.h $
// $Id: random_convex_set_2.h 28567 2006-02-16 14:30:13Z lsaboret $
//
//
// Author(s) : Michael Hoffmann <hoffmann@inf.ethz.ch>
#if ! (CGAL_RANDOM_CONVEX_SET_2_H)
#define CGAL_RANDOM_CONVEX_SET_2_H 1
#include <CGAL/basic.h>
#include <CGAL/copy_n.h>
#include <vector>
#include <algorithm>
#include <numeric>
#ifdef CGAL_REP_CLASS_DEFINED
#include <CGAL/Random_convex_set_traits_2.h>
#endif
CGAL_BEGIN_NAMESPACE
template < class OutputIterator, class Point_generator, class Traits >
OutputIterator
random_convex_set_2( int n,
OutputIterator o,
const Point_generator& pg,
Traits t)
{
CGAL_precondition( n >= 3);
using std::vector;
using std::back_inserter;
using std::accumulate;
using std::transform;
using std::bind2nd;
using std::sort;
using std::partial_sum;
using std::less;
using std::max_element;
using CGAL::copy_n;
typedef typename Traits::Point_2 Point_2;
typedef typename Traits::FT FT;
typedef vector< Point_2 > Container;
typedef typename Traits::Sum Sum;
typedef typename Traits::Scale Scale;
typedef typename Traits::Angle_less Angle_less;
typedef typename Traits::Max_coordinate Max_coordinate;
// GCC 2.8 and egcs-1.0.1 require these:
// (does not accept s.l. Scale()( p, 1))
Scale scale;
Max_coordinate max_coordinate;
Sum sum;
// build random point set:
Container points;
points.reserve( n);
CGAL::copy_n( pg, n, back_inserter( points));
// compute centroid of points:
Point_2 centroid(
scale(
accumulate( points.begin(), points.end(), t.origin(), Sum()),
FT( 1) / FT( n)));
// translate s.t. centroid == origin:
transform(
points.begin(),
points.end(),
points.begin(),
bind2nd( Sum(), scale( centroid, FT( -1))));
// sort them according to their direction's angle
// w.r.t. the positive x-axis:
sort( points.begin(), points.end(), Angle_less());
// construct polygon:
partial_sum(
points.begin(), points.end(), points.begin(), Sum());
// and compute its centroid:
Point_2 new_centroid(
scale(
accumulate( points.begin(), points.end(), t.origin(), Sum()),
FT( 1) / FT( n)));
// translate s.t. centroids match:
transform(
points.begin(),
points.end(),
points.begin(),
bind2nd( Sum(), sum( centroid,
scale( new_centroid, FT( -1)))));
// compute maximal coordinate:
FT maxcoord( max_coordinate(
*max_element( points.begin(),
points.end(),
compose2_2( less< FT >(),
Max_coordinate(),
Max_coordinate()))));
// and finally scale to fit into original grid:
return transform(
points.begin(),
points.end(),
o,
bind2nd( Scale(), FT( pg.range()) / maxcoord));
} // random_convex_set_2( n, o, pg, t)
CGAL_END_NAMESPACE
#endif // ! (CGAL_RANDOM_CONVEX_SET_2_H)
// ----------------------------------------------------------------------------
// ** EOF
// ----------------------------------------------------------------------------
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