cgal/Homogeneous_kernel/include/CGAL/Homogeneous/VectorH3.h

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// Copyright (c) 1999 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.
//
// $URL$
// $Id$
//
//
// Author(s) : Stefan Schirra
#ifndef CGAL_HOMOGENEOUS_VECTOR_3_H
#define CGAL_HOMOGENEOUS_VECTOR_3_H
#include <CGAL/Origin.h>
#include <CGAL/Fourtuple.h>
CGAL_BEGIN_NAMESPACE
template < class R_ >
class VectorH3
{
typedef typename R_::RT RT;
typedef typename R_::FT FT;
typedef typename R_::Point_3 Point_3;
typedef typename R_::Vector_3 Vector_3;
typedef typename R_::Segment_3 Segment_3;
typedef typename R_::Ray_3 Ray_3;
typedef typename R_::Line_3 Line_3;
typedef typename R_::Direction_3 Direction_3;
typedef Fourtuple<RT> Rep;
typedef typename R_::template Handle<Rep>::type Base;
Base base;
public:
typedef R_ R;
VectorH3() {}
VectorH3(const Point_3& a, const Point_3& b)
{ *this = R().construct_vector_3_object()(a, b); }
VectorH3(const Segment_3& s)
{ *this = R().construct_vector_3_object()(s); }
VectorH3(const Ray_3& r)
{ *this = R().construct_vector_3_object()(r); }
VectorH3(const Line_3& l)
{ *this = R().construct_vector_3_object()(l); }
VectorH3(const Null_vector&)
: base(RT(0), RT(0), RT(0), RT(1)) {}
VectorH3(const RT& x, const RT& y, const RT& z)
: base(x, y, z, RT(1)) {}
VectorH3(const RT& w, const RT& x, const RT& y, const RT& z);
const RT & hx() const { return get(base).e0 ; }
const RT & hy() const { return get(base).e1 ; }
const RT & hz() const { return get(base).e2 ; }
const RT & hw() const { return get(base).e3 ; }
FT x() const { return FT(hx())/FT(hw()) ; }
FT y() const { return FT(hy())/FT(hw()) ; }
FT z() const { return FT(hz())/FT(hw()) ; }
const RT & homogeneous(int i) const;
FT cartesian(int i) const;
FT operator[](int i) const;
int dimension() const { return 3; };
Direction_3 direction() const;
Vector_3 operator-() const;
bool operator==( const VectorH3<R>& v) const;
bool operator!=( const VectorH3<R>& v) const;
Vector_3 operator+( const VectorH3 &v) const;
Vector_3 operator-( const VectorH3 &v) const;
FT squared_length() const;
Vector_3 operator/( const RT &f) const;
Vector_3 operator/( const FT &f) const;
};
template < class R >
CGAL_KERNEL_INLINE
VectorH3<R>::VectorH3(const RT& x, const RT& y, const RT& z, const RT& w)
{
if ( w >= RT(0) )
base = Rep(x, y, z, w);
else
base = Rep(-x,-y,-z,-w);
}
template < class R >
CGAL_KERNEL_INLINE
typename VectorH3<R>::FT
VectorH3<R>::cartesian(int i) const
{
CGAL_kernel_precondition(i == 0 || i == 1 || i == 2);
switch (i)
{
case 0: return x();
case 1: return y();
}
return z();
}
template < class R >
CGAL_KERNEL_INLINE
const typename VectorH3<R>::RT &
VectorH3<R>::homogeneous(int i) const
{
CGAL_kernel_precondition(i == 0 || i == 1 || i == 2 || i == 3);
switch (i)
{
case 0: return hx();
case 1: return hy();
case 2: return hz();
}
return hw() ;
}
template < class R >
inline
typename VectorH3<R>::Direction_3
VectorH3<R>::direction() const
{ return Direction_3(hx(), hy(), hz()); }
template < class R >
CGAL_KERNEL_INLINE
bool
VectorH3<R>::operator==( const VectorH3<R>& v) const
{
return ( (hx() * v.hw() == v.hx() * hw() )
&&(hy() * v.hw() == v.hy() * hw() )
&&(hz() * v.hw() == v.hz() * hw() ) );
}
template < class R >
inline
bool
VectorH3<R>::operator!=( const VectorH3<R>& v) const
{ return !(*this == v); }
template < class R >
inline
typename VectorH3<R>::FT
VectorH3<R>::operator[](int i) const
{ return cartesian(i); }
template < class R >
CGAL_KERNEL_INLINE
typename VectorH3<R>::Vector_3
VectorH3<R>::operator-() const
{ return Vector_3( - hx(), - hy(), -hz(), hw() ); }
template <class R>
CGAL_KERNEL_INLINE
typename R::Vector_3
VectorH3<R>::operator+(const VectorH3<R>& v) const
{
return typename R::Vector_3(hx()*v.hw() + v.hx()*hw(),
hy()*v.hw() + v.hy()*hw(),
hz()*v.hw() + v.hz()*hw(),
hw()*v.hw() );
}
template <class R>
CGAL_KERNEL_INLINE
typename R::Vector_3
VectorH3<R>::operator-(const VectorH3<R>& v) const
{
return typename R::Vector_3(hx()*v.hw() - v.hx()*hw(),
hy()*v.hw() - v.hy()*hw(),
hz()*v.hw() - v.hz()*hw(),
hw()*v.hw() );
}
template <class R>
CGAL_KERNEL_INLINE
typename VectorH3<R>::FT
VectorH3<R>::squared_length() const
{
typedef typename R::FT FT;
return
FT( CGAL_NTS square(hx()) +
CGAL_NTS square(hy()) +
CGAL_NTS square(hz()) ) /
FT( CGAL_NTS square(hw()) );
}
template <class R>
CGAL_KERNEL_INLINE
typename R::Vector_3
VectorH3<R>::operator/(const typename VectorH3<R>::RT& f) const
{ return typename R::Vector_3( hx(), hy(), hz(), hw()*f ); }
template <class R>
CGAL_KERNEL_INLINE
typename R::Vector_3
VectorH3<R>::operator/(const typename VectorH3<R>::FT& f) const
{ return typename R::Vector_3(hx()*f.denominator(), hy()*f.denominator(),
hz()*f.denominator(), hw()*f.numerator() ); }
CGAL_END_NAMESPACE
#endif // CGAL_HOMOGENEOUS_VECTOR_3_H