dust3d/thirdparty/cgal/CGAL-4.13/include/CGAL/Homogeneous/DirectionH2.h

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// Copyright (c) 1999
// Utrecht University (The Netherlands),
// ETH Zurich (Switzerland),
// INRIA Sophia-Antipolis (France),
// Max-Planck-Institute Saarbruecken (Germany),
// 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; either version 3 of the License,
// or (at your option) any later version.
//
// 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.
//
// $URL$
// $Id$
// SPDX-License-Identifier: LGPL-3.0+
//
//
// Author(s) : Stefan Schirra
#ifndef CGAL_HOMOGENEOUS_DIRECTION_2_H
#define CGAL_HOMOGENEOUS_DIRECTION_2_H
#include <CGAL/array.h>
#include <CGAL/Handle_for.h>
#include <CGAL/kernel_config.h>
#include <CGAL/number_type_basic.h>
namespace CGAL {
template < class R_ >
class DirectionH2
{
typedef DirectionH2<R_> Self;
typedef typename R_::FT FT;
typedef typename R_::RT RT;
typedef typename R_::Point_2 Point_2;
typedef typename R_::Vector_2 Vector_2;
typedef typename R_::Line_2 Line_2;
typedef typename R_::Ray_2 Ray_2;
typedef typename R_::Segment_2 Segment_2;
typedef cpp11::array<RT, 3> Rep;
typedef typename R_::template Handle<Rep>::type Base;
Base base;
public:
typedef R_ R;
typedef const RT& Homogeneous_coordinate_type;
const Self&
rep() const
{
return static_cast<const Self& >(*this);
}
DirectionH2() {}
DirectionH2(const RT& x, const RT& y)
: base(CGAL::make_array(x, y, RT(1))) {}
// TODO Not documented : should not exist, not used.
// we should also change array<RT, 3> -> array<RT, 2>
DirectionH2(const RT& x, const RT& y, const RT& w )
: base( w > RT(0) ? CGAL::make_array(x, y, w)
: CGAL::make_array<RT>(-x, -y, -w) ) {}
bool operator==( const DirectionH2<R>& d) const;
bool operator!=( const DirectionH2<R>& d) const;
Vector_2 to_vector() const;
const RT & x() const { return CGAL::get_pointee_or_identity(base)[0]; }
const RT & y() const { return CGAL::get_pointee_or_identity(base)[1]; }
const RT & delta(int i) const;
const RT & dx() const { return CGAL::get_pointee_or_identity(base)[0]; }
const RT & dy() const { return CGAL::get_pointee_or_identity(base)[1]; }
};
template <class R >
CGAL_KERNEL_INLINE
bool
DirectionH2<R>::operator==( const DirectionH2<R>& d) const
{
return ( ( x() * d.y() == y() * d.x() )
&&( CGAL_NTS sign( x() ) == CGAL_NTS sign( d.x() ) )
&&( CGAL_NTS sign( y() ) == CGAL_NTS sign( d.y() ) ) );
}
template <class R >
inline
bool
DirectionH2<R>::operator!=( const DirectionH2<R>& d) const
{ return !(*this == d); }
} //namespace CGAL
#include <CGAL/Homogeneous/predicates_on_directionsH2.h>
namespace CGAL {
template <class R >
CGAL_KERNEL_INLINE
typename DirectionH2<R>::Vector_2
DirectionH2<R>::to_vector() const
{ return Vector_2(dx(), dy()); }
} //namespace CGAL
#endif // CGAL_HOMOGENEOUS_DIRECTION_2_H