cgal/Old_Packages/S2/include/CGAL/SimpleCartesian/DirectionS2.h

251 lines
6.0 KiB
C++

// ======================================================================
//
// Copyright (c) 1999 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 : 2000, August 16
//
// source : webS2/S2.lw
// file : include/CGAL/SimpleCartesian/DirectionS2.h
// package : S2 (1.7)
// maintainer : Stefan Schirra <stschirr@mpi-sb.mpg.de>
// revision : 1.6
// revision_date : 27 Jun 2000
// author(s) : Stefan Schirra
// based on code by
// Andreas Fabri and
// Herve Brönnimann
//
// coordinator : MPI, Saarbrücken
// ======================================================================
#ifndef CGAL_DIRECTIONS2_H
#define CGAL_DIRECTIONS2_H
#include <CGAL/SimpleCartesian/VectorS2.h>
CGAL_BEGIN_NAMESPACE
template < class FT >
class DirectionS2
{
public:
DirectionS2();
DirectionS2(const VectorS2<FT>& v);
DirectionS2(const FT& x, const FT &y);
bool operator==(const DirectionS2<FT>& d) const;
bool operator!=(const DirectionS2<FT>& d) const;
bool operator>=(const DirectionS2<FT>& d) const;
bool operator<=(const DirectionS2<FT>& d) const;
bool operator>(const DirectionS2<FT>& d) const;
bool operator<(const DirectionS2<FT>& d) const;
bool counterclockwise_in_between( const DirectionS2<FT>& d1,
const DirectionS2<FT>& d2) const;
VectorS2<FT> vector() const;
DirectionS2<FT> perpendicular(const Orientation& o) const;
DirectionS2<FT> transform(const Aff_transformationS2<FT>& t) const;
DirectionS2<FT> operator-() const;
FT delta(int i) const;
FT dx() const;
FT dy() const;
// private:
FT e0;
FT e1;
};
template < class FT >
CGAL_KERNEL_CTOR_INLINE
DirectionS2<FT>::DirectionS2() {}
template < class FT >
CGAL_KERNEL_CTOR_INLINE
DirectionS2<FT>::DirectionS2(const VectorS2<FT>& v)
{ e0 = v.e0; e1 = v.e1; }
template < class FT >
CGAL_KERNEL_CTOR_INLINE
DirectionS2<FT>::DirectionS2(const FT& x, const FT &y)
{ e0 = x; e1 = y; }
template < class FT >
bool
DirectionS2<FT>::operator==(const DirectionS2<FT>& d) const
{
// Use a S2 predicate for that ?
return (CGAL_NTS sign(dx()) == CGAL_NTS sign(d.dx()))
&& (CGAL_NTS sign(dy()) == CGAL_NTS sign(d.dy()))
&& (dy()*d.dx() == d.dy()*dx());
}
template < class FT >
inline
bool
DirectionS2<FT>::operator!=(const DirectionS2<FT>& d) const
{ return !( *this == d ); }
template < class FT >
CGAL_KERNEL_MEDIUM_INLINE
bool
DirectionS2<FT>::operator<(const DirectionS2<FT>& d) const
{
int quadrant_this = (dx() >= FT(0)) ? ((dy() >= FT(0))?1:4)
: ((dy() >= FT(0))?2:3);
int quadrant_d = (d.dx() >= FT(0)) ? ((d.dy() >= FT(0))?1:4)
: ((d.dy() >= FT(0))?2:3);
if(quadrant_this < quadrant_d)
return true;
else if (quadrant_this > quadrant_d)
return false;
else
return dy() * d.dx() < d.dy() * dx();
}
template < class FT >
CGAL_KERNEL_INLINE
bool
DirectionS2<FT>::operator>(const DirectionS2<FT>& d) const
{ return d < *this ; }
template < class FT >
CGAL_KERNEL_INLINE
bool
DirectionS2<FT>::operator>=(const DirectionS2<FT>& d) const
{ return (d < *this) || (d == *this) ; }
template < class FT >
CGAL_KERNEL_INLINE
bool
DirectionS2<FT>::operator<=(const DirectionS2<FT>& d) const
{ return (*this < d) || (d == *this) ; }
template < class FT >
CGAL_KERNEL_INLINE
bool
DirectionS2<FT>::counterclockwise_in_between(const DirectionS2<FT>& d1,
const DirectionS2<FT>& d2) const
{
if ( d1 < *this)
{
return ( *this < d2 )||( d2 <= d1 );
}
else
{
return ( *this < d2 )&&( d2 <= d1 );
}
}
template < class FT >
inline
VectorS2<FT>
DirectionS2<FT>::vector() const
{ return VectorS2<FT>(*this); }
template < class FT >
CGAL_KERNEL_MEDIUM_INLINE
DirectionS2<FT>
DirectionS2<FT>::perpendicular(const Orientation& o) const
{
CGAL_kernel_precondition(o != COLLINEAR);
if (o == COUNTERCLOCKWISE)
return DirectionS2<FT>(-dy(), dx());
else
return DirectionS2<FT>(dy(), -dx());
}
template < class FT >
CGAL_KERNEL_INLINE
DirectionS2<FT> DirectionS2<FT>::transform( const Aff_transformationS2<FT>& t) const
{ return t.transform(*this); }
template < class FT >
inline
DirectionS2<FT> DirectionS2<FT>::operator-() const
{ return DirectionS2<FT>(-dx(), -dy()); }
template < class FT >
CGAL_KERNEL_INLINE
FT
DirectionS2<FT>::delta(int i) const
{
CGAL_kernel_precondition( ( i == 0 ) || ( i == 1 ) );
return (i==0) ? dx() : dy();
}
template < class FT >
inline
FT
DirectionS2<FT>::dx() const
{ return e0; }
template < class FT >
inline
FT
DirectionS2<FT>::dy() const
{ return e1; }
#ifndef CGAL_NO_OSTREAM_INSERT_DIRECTIONS2
template < class FT >
std::ostream
&operator<<(std::ostream& os, const DirectionS2<FT> &d)
{
VectorS2<FT> v = d.vector();
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 << "DirectionS2(" << v.x() << ", " << v.y() << ')';
}
}
#endif // CGAL_NO_OSTREAM_INSERT_DIRECTIONS2
#ifndef CGAL_NO_ISTREAM_EXTRACT_DIRECTIONS2
template < class FT >
std::istream
&operator>>(std::istream& is, DirectionS2<FT> &p)
{
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 << "Stream must be in ascii or binary mode" << std::endl;
break;
}
p = DirectionS2<FT>(x, y);
return is;
}
#endif // CGAL_NO_ISTREAM_EXTRACT_DIRECTIONS2
CGAL_END_NAMESPACE
#endif