// ======================================================================
//
// Copyright (c) 2000 The CGAL Consortium
//
// This software and related documentation is part of an INTERNAL release
// of the Computational Geometry Algorithms Library (CGAL). It is not
// intended for general use.
//
// ----------------------------------------------------------------------
//
// release       :
// release_date  :
//
// file          : include/CGAL/Cartesian/Vector_2.C
// revision      : $Revision$
// revision_date : $Date$
// author(s)     : Andreas Fabri, Herve Bronnimann
// coordinator   : INRIA Sophia-Antipolis (Mariette.Yvinec@sophia.inria.fr)
//
// ======================================================================

#ifndef CGAL_CARTESIAN_VECTOR_2_C
#define CGAL_CARTESIAN_VECTOR_2_C

#include <CGAL/Cartesian/Direction_2.h>

#ifndef CGAL_CARTESIAN_REDEFINE_NAMES_2_H
#define CGAL_CTAG
#endif

#ifdef CGAL_CFG_TYPENAME_BUG
#define typename
#endif

CGAL_BEGIN_NAMESPACE

template < class R >
VectorC2<R CGAL_CTAG>::VectorC2()
{
  new ( static_cast< void*>(ptr)) Twotuple<FT>(); 
}

template < class R >
CGAL_KERNEL_CTOR_INLINE
VectorC2<R CGAL_CTAG>::VectorC2(const VectorC2<R CGAL_CTAG>  &v) :
  Handle_for<Twotuple<typename R::FT> >(v)
{}

template < class R >
CGAL_KERNEL_CTOR_INLINE
VectorC2<R CGAL_CTAG>::VectorC2(const Null_vector &)
{
  new ( static_cast< void*>(ptr)) Twotuple<FT>(FT(0), FT(0));
}

template < class R >
CGAL_KERNEL_CTOR_MEDIUM_INLINE
VectorC2<R CGAL_CTAG>::VectorC2(const typename VectorC2<R CGAL_CTAG>::FT &hx,
                                const typename VectorC2<R CGAL_CTAG>::FT &hy,
				const typename VectorC2<R CGAL_CTAG>::FT &hw)
{
  if( hw != FT(1))
    new ( static_cast< void*>(ptr)) Twotuple<FT>(hx/hw, hy/hw);
  else
    new ( static_cast< void*>(ptr)) Twotuple<FT>(hx, hy);
}

template < class R >
CGAL_KERNEL_CTOR_INLINE
VectorC2<R CGAL_CTAG>::VectorC2(const typename VectorC2<R CGAL_CTAG>::FT &x,
                                const typename VectorC2<R CGAL_CTAG>::FT &y)
{
  new ( static_cast< void*>(ptr)) Twotuple<FT>(x, y);
}

template < class R >
inline
VectorC2<R CGAL_CTAG>::~VectorC2()
{}

template < class R >
CGAL_KERNEL_CTOR_INLINE
VectorC2<R CGAL_CTAG>::
VectorC2(const typename VectorC2<R CGAL_CTAG>::Point_2 &p)
  : Handle_for<Twotuple<typename R::FT> > (p)
{}

template < class R >
CGAL_KERNEL_CTOR_INLINE
VectorC2<R CGAL_CTAG>::
VectorC2(const typename VectorC2<R CGAL_CTAG>::Direction_2 &d)
  : Handle_for<Twotuple<typename R::FT> > (d)
{}

template < class R >
inline
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::x() const
{
  return ptr->e0;
}

template < class R >
inline
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::y() const
{
  return ptr->e1;
}

template < class R >
CGAL_KERNEL_INLINE
bool
VectorC2<R CGAL_CTAG>::operator==(const VectorC2<R CGAL_CTAG> &v) const
{
  return x() == v.x() && y() == v.y();
}

template < class R >
inline
bool
VectorC2<R CGAL_CTAG>::operator!=(const VectorC2<R CGAL_CTAG> &v) const
{
  return !(*this == v);
}

template < class R >
inline
bool
VectorC2<R CGAL_CTAG>::operator==(const Null_vector &) const
{
  return x() == FT(0) && y() == FT(0);
}

template < class R >
inline
bool
VectorC2<R CGAL_CTAG>::operator!=(const Null_vector &v) const
{
  return !(*this == v);
}

template < class R >
CGAL_KERNEL_INLINE
typename VectorC2<R CGAL_CTAG>::FT 
VectorC2<R CGAL_CTAG>::cartesian(int i) const
{
  CGAL_kernel_precondition( (i == 0) || (i == 1) );
  return (i == 0) ? x() : y();
}

template < class R >
inline
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::operator[](int i) const
{
  return cartesian(i);
}

template < class R >
inline
int
VectorC2<R CGAL_CTAG>::dimension() const
{
  return 2;
}

template < class R >
inline
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::hx() const
{
  return x();
}

template < class R >
inline
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::hy()  const
{
  return y();
}

template < class R >
inline
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::hw()  const
{
  return FT(1);
}

template < class R >
CGAL_KERNEL_INLINE
typename VectorC2<R CGAL_CTAG>::FT 
VectorC2<R CGAL_CTAG>::homogeneous(int i) const
{
  return (i == 2) ? FT(1) : cartesian(i);
}

template < class R >
CGAL_KERNEL_INLINE
VectorC2<R CGAL_CTAG>
VectorC2<R CGAL_CTAG>::operator+(const VectorC2<R CGAL_CTAG> &w) const
{
  return VectorC2<R CGAL_CTAG>(x() + w.x(), y() + w.y());
}

template < class R >
CGAL_KERNEL_INLINE
VectorC2<R CGAL_CTAG>
VectorC2<R CGAL_CTAG>::operator-(const VectorC2<R CGAL_CTAG> &w) const
{
  return VectorC2<R CGAL_CTAG>(x() - w.x(), y() - w.y());
}

template < class R >
CGAL_KERNEL_INLINE
VectorC2<R CGAL_CTAG>
VectorC2<R CGAL_CTAG>::operator-() const
{
  return VectorC2<R CGAL_CTAG>(-x(), -y());
}

template < class R >
CGAL_KERNEL_INLINE
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::operator*(const VectorC2<R CGAL_CTAG> &w) const
{
  return x() * w.x() + y() * w.y();
}

template < class R >
CGAL_KERNEL_INLINE
typename VectorC2<R CGAL_CTAG>::FT
VectorC2<R CGAL_CTAG>::squared_length() const
{
  return CGAL_NTS square(x()) + CGAL_NTS square(y());
}

template < class R >
CGAL_KERNEL_INLINE
VectorC2<R CGAL_CTAG>
VectorC2<R CGAL_CTAG>::
operator/(const typename VectorC2<R CGAL_CTAG>::FT &c) const
{
  return VectorC2<R CGAL_CTAG>( x()/c, y()/c);
}

template < class R >
inline
typename VectorC2<R CGAL_CTAG>::Direction_2
VectorC2<R CGAL_CTAG>::direction() const
{
  return Direction_2(*this);
}

template < class R >
CGAL_KERNEL_MEDIUM_INLINE
VectorC2<R CGAL_CTAG>
VectorC2<R CGAL_CTAG>::perpendicular(const Orientation &o) const
{
  CGAL_kernel_precondition( o != COLLINEAR );
  if (o == COUNTERCLOCKWISE)
    return VectorC2<R CGAL_CTAG>(-y(), x());
  else
    return VectorC2<R CGAL_CTAG>(y(), -x());
}

template < class R >
inline
VectorC2<R CGAL_CTAG>
VectorC2<R CGAL_CTAG>::
transform(const typename VectorC2<R CGAL_CTAG>::Aff_transformation_2 &t) const
{
  return t.transform(*this);
}

#ifndef CGAL_NO_OSTREAM_INSERT_VECTORC2
template < class R >
std::ostream &
operator<<(std::ostream &os, const VectorC2<R CGAL_CTAG> &v)
{
    switch(os.iword(IO::mode)) {
    case IO::ASCII :
        return os << v.x() << ' ' << v.y();
    case IO::BINARY :
        write(os, v.x());
        write(os, v.y());
        return os;
    default:
        return os << "VectorC2(" << v.x() << ", " << v.y() << ')';
    }
}
#endif // CGAL_NO_OSTREAM_INSERT_VECTORC2

#ifndef CGAL_NO_ISTREAM_EXTRACT_VECTORC2
template < class R >
std::istream &
operator>>(std::istream &is, VectorC2<R CGAL_CTAG> &p)
{
    typename VectorC2<R CGAL_CTAG>::FT x, y;
    switch(is.iword(IO::mode)) {
    case IO::ASCII :
        is >> x >> y;
        break;
    case IO::BINARY :
        read(is, x);
        read(is, y);
        break;
    default:
        std::cerr << "" << std::endl;
        std::cerr << "Stream must be in ascii or binary mode" << std::endl;
        break;
    }
    p = VectorC2<R CGAL_CTAG>(x, y);
    return is;
}
#endif // CGAL_NO_ISTREAM_EXTRACT_VECTORC2

CGAL_END_NAMESPACE

#ifdef CGAL_CFG_TYPENAME_BUG
#undef typename
#endif

#endif // CGAL_CARTESIAN_VECTOR_2_C