cgal/Packages/Cartesian_kernel/include/CGAL/Cartesian/Line_2.h

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C++

// Copyright (c) 2000 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.
//
// $Source$
// $Revision$ $Date$
// $Name$
//
// Author(s) : Andreas Fabri, Herve Bronnimann
#ifndef CGAL_CARTESIAN_LINE_2_H
#define CGAL_CARTESIAN_LINE_2_H
#include <CGAL/Threetuple.h>
#include <CGAL/predicates/kernel_ftC2.h>
CGAL_BEGIN_NAMESPACE
template < class R_ >
class LineC2
{
typedef typename R_::FT FT;
typedef typename R_::Point_2 Point_2;
typedef typename R_::Direction_2 Direction_2;
typedef typename R_::Vector_2 Vector_2;
typedef typename R_::Ray_2 Ray_2;
typedef typename R_::Segment_2 Segment_2;
typedef typename R_::Line_2 Line_2;
typedef typename R_::Aff_transformation_2 Aff_transformation_2;
typedef Threetuple<FT> Rep;
typedef typename R_::template Handle<Rep>::type Base;
Base base;
public:
typedef R_ R;
LineC2() {}
LineC2(const Point_2 &p, const Point_2 &q)
{ *this = R().construct_line_2_object()(p, q); }
LineC2(const FT &a, const FT &b, const FT &c)
: base(a, b, c) {}
LineC2(const Segment_2 &s)
{ *this = R().construct_line_2_object()(s); }
LineC2(const Ray_2 &r)
{ *this = R().construct_line_2_object()(r); }
LineC2(const Point_2 &p, const Direction_2 &d)
{ *this = R().construct_line_2_object()(p, d); }
LineC2(const Point_2 &p, const Vector_2 &v)
{ *this = R().construct_line_2_object()(p, v); }
bool operator==(const LineC2 &l) const;
bool operator!=(const LineC2 &l) const;
const FT & a() const
{
return get(base).e0;
}
const FT & b() const
{
return get(base).e1;
}
const FT & c() const
{
return get(base).e2;
}
FT x_at_y(const FT &y) const;
FT y_at_x(const FT &x) const;
Line_2 perpendicular(const Point_2 &p) const;
Line_2 opposite() const;
Point_2 point(int i) const;
Point_2 point() const;
Point_2 projection(const Point_2 &p) const;
Direction_2 direction() const;
Vector_2 to_vector() const;
Oriented_side oriented_side(const Point_2 &p) const;
bool has_on_boundary(const Point_2 &p) const;
bool has_on_positive_side(const Point_2 &p) const;
bool has_on_negative_side(const Point_2 &p) const;
bool has_on(const Point_2 &p) const { return has_on_boundary(p); }
bool is_horizontal() const;
bool is_vertical() const;
bool is_degenerate() const;
Line_2 transform(const Aff_transformation_2 &t) const
{
return LineC2<R>(t.transform(point(0)),
t.transform(direction()));
}
};
template < class R >
CGAL_KERNEL_INLINE
bool
LineC2<R>::operator==(const LineC2<R> &l) const
{
if (CGAL::identical(base, l.base))
return true;
return equal_lineC2(a(), b(), c(), l.a(), l.b(), l.c());
}
template < class R >
inline
bool
LineC2<R>::operator!=(const LineC2<R> &l) const
{
return ! (*this == l);
}
template < class R >
inline
bool
LineC2<R>::is_horizontal() const
{ // FIXME : predicate
return CGAL_NTS is_zero(a());
}
template < class R >
inline
bool
LineC2<R>::is_vertical() const
{ // FIXME : predicate
return CGAL_NTS is_zero(b());
}
template < class R >
CGAL_KERNEL_INLINE
typename LineC2<R>::FT
LineC2<R>::x_at_y(const typename LineC2<R>::FT &y) const
{
CGAL_kernel_precondition_msg( ! is_horizontal(),
"Line::x_at_y(FT y) is undefined for horizontal line");
return line_x_at_y(*this, y);
}
template < class R >
CGAL_KERNEL_INLINE
typename LineC2<R>::FT
LineC2<R>::y_at_x(const typename LineC2<R>::FT &x) const
{
CGAL_kernel_precondition_msg( ! is_vertical(),
"Line::y_at_x(FT x) is undefined for vertical line");
return line_y_at_x(*this, x);
}
template < class R >
inline
typename LineC2<R>::Line_2
LineC2<R>::
perpendicular(const typename LineC2<R>::Point_2 &p) const
{
typename R::FT fta, ftb, ftc;
perpendicular_through_pointC2(a(), b(), p.x(), p.y(), fta, ftb, ftc);
return Line_2(fta, ftb, ftc);
}
template < class R >
inline
typename LineC2<R>::Line_2
LineC2<R>::opposite() const
{
return LineC2<R>( -a(), -b(), -c() );
}
template < class R >
CGAL_KERNEL_INLINE
typename LineC2<R>::Point_2
LineC2<R>::point(int i) const
{
typename R::FT x, y;
typename R::Construct_point_2 construct_point_2;
line_get_pointC2(a(), b(), c(), i, x, y);
return construct_point_2(x,y);
}
template < class R >
CGAL_KERNEL_INLINE
typename LineC2<R>::Point_2
LineC2<R>::point() const
{
typename R::FT x, y;
typename R::Construct_point_2 construct_point_2;
line_get_pointC2(a(), b(), c(), 0, x, y);
return construct_point_2(x,y);
}
template < class R >
CGAL_KERNEL_MEDIUM_INLINE
typename LineC2<R>::Point_2
LineC2<R>::
projection(const typename LineC2<R>::Point_2 &p) const
{
typename R::FT x, y;
typename R::Construct_point_2 construct_point_2;
line_project_pointC2(a(), b(), c(), p.x(), p.y(), x, y);
return construct_point_2(x, y);
}
template < class R >
inline
typename LineC2<R>::Direction_2
LineC2<R>::direction() const
{
return Direction_2( b(), -a() );
}
template < class R >
inline
typename LineC2<R>::Vector_2
LineC2<R>::to_vector() const
{
return Vector_2( b(), -a() );
}
template < class R >
CGAL_KERNEL_INLINE
Oriented_side
LineC2<R>::
oriented_side(const typename LineC2<R>::Point_2 &p) const
{
return side_of_oriented_lineC2(a(), b(), c(), p.x(), p.y());
}
template < class R >
inline
bool
LineC2<R>::
has_on_boundary(const typename LineC2<R>::Point_2 &p) const
{
return oriented_side(p) == ON_ORIENTED_BOUNDARY;
}
template < class R >
inline
bool
LineC2<R>::
has_on_positive_side(const typename LineC2<R>::Point_2 &p) const
{
return oriented_side(p) == ON_POSITIVE_SIDE;
}
template < class R >
CGAL_KERNEL_INLINE
bool
LineC2<R>::
has_on_negative_side(const typename LineC2<R>::Point_2 &p) const
{
return oriented_side(p) == ON_NEGATIVE_SIDE;
}
template < class R >
inline
bool
LineC2<R>::is_degenerate() const
{
return is_horizontal() && is_vertical();
}
#ifndef CGAL_NO_OSTREAM_INSERT_LINEC2
template < class R >
std::ostream &
operator<<(std::ostream &os, const LineC2<R> &l)
{
switch(os.iword(IO::mode)) {
case IO::ASCII :
return os << l.a() << ' ' << l.b() << ' ' << l.c();
case IO::BINARY :
write(os, l.a());
write(os, l.b());
write(os, l.c());
return os;
default:
return os << "LineC2(" << l.a()
<< ", " << l.b() << ", " << l.c() <<')';
}
}
#endif // CGAL_NO_OSTREAM_INSERT_LINEC2
#ifndef CGAL_NO_ISTREAM_EXTRACT_LINEC2
template < class R >
std::istream &
operator>>(std::istream &is, LineC2<R> &l)
{
typename R::FT a, b, c;
switch(is.iword(IO::mode)) {
case IO::ASCII :
is >> a >> b >> c;
break;
case IO::BINARY :
read(is, a);
read(is, b);
read(is, c);
break;
default:
std::cerr << "" << std::endl;
std::cerr << "Stream must be in ascii or binary mode" << std::endl;
break;
}
if (is)
l = LineC2<R>(a, b, c);
return is;
}
#endif // CGAL_NO_ISTREAM_EXTRACT_LINEC2
CGAL_END_NAMESPACE
#endif // CGAL_CARTESIAN_LINE_2_H