cgal/Convex_hull_2/include/CGAL/ch_function_objects_2.h

72 lines
1.7 KiB
C++

// Copyright (c) 2002 Max-Planck-Institute Saarbruecken (Germany).
// 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.
//
// $URL$
// $Id$
//
//
// Author(s) : Susan Hert
#ifndef CGAL_CH_FUNCTION_OBJECTS_2_H
#define CGAL_CH_FUNCTION_OBJECTS_2_H
CGAL_BEGIN_NAMESPACE
namespace internal {
template <class R>
class r_Less_dist_to_line
{
public:
typedef bool result_type;
typedef typename R::Point_2 Point;
typedef typename R::Line_2 Line;
r_Less_dist_to_line() : line_constructed( false )
{ }
bool operator()(const Point& a, const Point& b,
const Point& c, const Point& d) const
{
if (!line_constructed)
{
line_constructed = true;
l_ab = Line(a,b);
}
Comparison_result res = compare_signed_distance_to_line(l_ab, c, d);
if ( res == SMALLER )
{
return true;
}
else if ( res == EQUAL )
{
return lexicographically_xy_smaller( c, d );
}
else
{
return false;
}
}
private:
mutable bool line_constructed;
mutable Line l_ab;
};
} // namespace internal
CGAL_END_NAMESPACE
#endif // CGAL_CH_FUNCTION_OBJECTS_2_H