cgal/Packages/Apollonius_graph_2/include/CGAL/Parabola_segment_2.h

165 lines
3.5 KiB
C++

// ======================================================================
//
// Copyright (c) 2003 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/Parabola_segment_2.h
// package : Apollonius_graph_2
// source : $RCSfile$
// revision : $Revision$
// revision_date : $Date$
// author(s) : Menelaos Karavelas <mkaravel@cse.nd.edu>
//
// coordinator :
//
// ======================================================================
#ifndef CGAL_PARABOLA_SEGMENT_2_H
#define CGAL_PARABOLA_SEGMENT_2_H
#include <CGAL/Parabola_2.h>
#ifdef CGAL_USE_QT
#include <CGAL/IO/Qt_widget.h>
#endif
CGAL_BEGIN_NAMESPACE
template < class Gt >
class Parabola_segment_2 : public Parabola_2< Gt >
{
typedef CGAL::Parabola_2<Gt> Base;
typedef typename Base::Site_2 Site_2;
typedef typename Base::FT FT;
typedef typename Base::Point_2 Point_2;
typedef typename Base::Segment_2 Segment_2;
typedef typename Base::Line_2 Line_2;
protected:
Point_2 p1, p2;
public:
Parabola_segment_2() : Parabola_2< Gt >() {}
Parabola_segment_2(const Site_2 &p, const Line_2 &l,
const Point_2 &p1, const Point_2 &p2) :
Parabola_2< Gt >(p, l)
{
this->p1 = p1;
this->p2 = p2;
}
void generate_points(std::vector<Point_2>& p) const
{
FT s[2];
s[0] = t(p1);
s[1] = t(p2);
if (CGAL_NTS compare(s[0], s[1]) == LARGER) {
#if defined(__GNUC__) && (__GNUC__ < 3)
swap< FT >(s[0], s[1]);
#else
std::swap< FT >(s[0], s[1]);
#endif
}
p.clear();
if ( !(CGAL_NTS is_positive(s[0])) &&
!(CGAL_NTS is_negative(s[1])) ) {
FT tt;
int k;
p.push_back( this->o );
k = 1;
tt = -this->STEP;
while ( CGAL_NTS compare(tt, s[0]) == LARGER ) {
p.insert( p.begin(), f(tt) );
k--;
tt = -FT(k * k) * this->STEP;
}
p.insert( p.begin(), f(s[0]) );
k = 1;
tt = this->STEP;
while ( CGAL_NTS compare(tt, s[1]) == SMALLER ) {
p.push_back( f(tt) );
k++;
tt = FT(k * k) * this->STEP;
}
p.push_back( f(s[1]) );
} else if ( !(CGAL_NTS is_negative(s[0])) &&
!(CGAL_NTS is_negative(s[1])) ) {
FT tt;
int k;
p.push_back( f(s[0]) );
tt = s[0];
k = int(CGAL_NTS to_double(CGAL_NTS sqrt(tt / this->STEP)));
while ( CGAL_NTS compare(tt, s[1]) == SMALLER ) {
if ( CGAL_NTS compare(tt, s[0]) != SMALLER )
p.push_back( f(tt) );
k++;
tt = FT(k * k) * this->STEP;
}
p.push_back( f(s[1]) );
} else {
FT tt;
int k;
p.push_back( f(s[1]) );
tt = s[1];
k = int(CGAL_NTS to_double(-CGAL_NTS sqrt(-tt / this->STEP)));
while ( CGAL_NTS compare(tt, s[0]) == LARGER ) {
if ( CGAL_NTS compare(tt, s[1]) != LARGER )
p.push_back( f(tt) );
k--;
tt = -FT(k * k) * this->STEP;
}
p.push_back( f(s[0]) );
}
}
template< class Stream >
void draw(Stream& W) const
{
std::vector< Point_2 > p;
generate_points(p);
for (unsigned int i = 0; i < p.size() - 1; i++) {
W << Segment_2(p[i], p[i+1]);
}
}
};
template< class Stream, class Gt >
inline
Stream& operator<<(Stream &s, const Parabola_segment_2<Gt> &P)
{
P.draw(s);
return s;
}
CGAL_END_NAMESPACE
#endif // CGAL_PARABOLA_SEGMENT_2_H