dust3d/thirdparty/cgal/CGAL-4.13/include/CGAL/Parabola_segment_2.h

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// Copyright (c) 2003,2004 INRIA Sophia-Antipolis (France).
// 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
// General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// 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.
//
// $URL$
// $Id$
// SPDX-License-Identifier: GPL-3.0+
//
//
// Author(s) : Menelaos Karavelas <mkaravel@iacm.forth.gr>
#ifndef CGAL_PARABOLA_SEGMENT_2_H
#define CGAL_PARABOLA_SEGMENT_2_H
#include <CGAL/license/Apollonius_graph_2.h>
#include <CGAL/Parabola_2.h>
namespace CGAL {
namespace Qt {
template <typename K> class PainterOstream;
}
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;
using Base::t;
using Base::f;
protected:
Point_2 p1, p2;
public:
Parabola_segment_2() : Parabola_2< Gt >() {}
template<class ApolloniusSite>
Parabola_segment_2(const ApolloniusSite &p, const Line_2 &l,
const Point_2 &p1, const Point_2 &p2)
: Parabola_2< Gt >(p, l)
{
this->p1 = p1;
this->p2 = p2;
}
Parabola_segment_2(const Point_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;
}
int compute_k(const FT& tt) const {
return int(CGAL::sqrt(CGAL::to_double(tt) / 2));
}
void generate_points(std::vector<Point_2>& p) const
{
const FT STEP(2);
FT s0, s1;
s0 = t(p1);
s1 = t(p2);
if (CGAL::compare(s0, s1) == LARGER) {
std::swap(s0, s1);
}
p.clear();
if ( !(CGAL::is_positive(s0)) &&
!(CGAL::is_negative(s1)) ) {
FT tt;
int k;
p.push_back( this->o );
k = -1;
tt = - STEP;
while ( CGAL::compare(tt, s0) == LARGER ) {
p.insert( p.begin(), f(tt) );
k--;
tt = -FT(k * k) * STEP;
}
p.insert( p.begin(), f(s0) );
k = 1;
tt = STEP;
while ( CGAL::compare(tt, s1) == SMALLER ) {
p.push_back( f(tt) );
k++;
tt = FT(k * k) * STEP;
}
p.push_back( f(s1) );
} else if ( !(CGAL::is_negative(s0)) &&
!(CGAL::is_negative(s1)) ) {
FT tt;
int k;
p.push_back( f(s0) );
tt = s0;
k = compute_k(tt);
while ( CGAL::compare(tt, s1) == SMALLER ) {
if ( CGAL::compare(tt, s0) != SMALLER )
p.push_back( f(tt) );
k++;
tt = FT(k * k) * STEP;
}
p.push_back( f(s1) );
} else {
FT tt;
int k;
p.push_back( f(s1) );
tt = s1;
k = -compute_k(-tt);
while ( CGAL::compare(tt, s0) == LARGER ) {
if ( CGAL::compare(tt, s1) != LARGER )
p.push_back( f(tt) );
k--;
tt = -FT(k * k) * STEP;
}
p.push_back( f(s0) );
}
}
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 K >
void draw(CGAL::Qt::PainterOstream<K>& stream) const {
stream.draw_parabola_segment(this->center(), this->line(), p1, p2);
}
};
template< class Stream, class Gt >
inline
Stream& operator<<(Stream &s, const Parabola_segment_2<Gt> &P)
{
P.draw(s);
return s;
}
} //namespace CGAL
#endif // CGAL_PARABOLA_SEGMENT_2_H