cgal/Packages/Arrangement/include/CGAL/Pm_with_intersections_misc.h

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// Copyright (c) 2000 Tel-Aviv University (Israel).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL 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) : Eyal flato <flato@math.tau.ac.il>
#ifndef CGAL_PM_WITH_INTERSECTIONS_MISC_H
#define CGAL_PM_WITH_INTERSECTIONS_MISC_H
#include <CGAL/Planar_map_2/Pm_traits_wrap_2.h>
#include <CGAL/tags.h>
CGAL_BEGIN_NAMESPACE
template <class I>
class Planar_map_with_intersections_traits_wrap :
public Pm_traits_wrap_2<I>
{
public:
typedef Pm_traits_wrap_2<I> Base;
typedef typename Base::X_monotone_curve_2 X_monotone_curve_2;
typedef typename Base::Point_2 Point_2;
typedef typename I::Has_left_category Has_left_category;
Planar_map_with_intersections_traits_wrap() : Base() {}
Planar_map_with_intersections_traits_wrap(const Base & tw) : Base(tw) {}
void directed_curve_split(const X_monotone_curve_2 & cv,
const Point_2 & first_pnt,
const Point_2 & split_pnt,
X_monotone_curve_2 & split1,
X_monotone_curve_2 & split2)
{
CGAL_assertion(point_equal(curve_source(cv), first_pnt) ||
point_equal(curve_target(cv), first_pnt));
CGAL_assertion(!point_equal(curve_source(cv), split_pnt));
CGAL_assertion(!point_equal(curve_target(cv), split_pnt));
curve_split(cv, split1, split2, split_pnt);
// if (!point_equal(curve_source(split1), first_pnt)) //start flip
// {
// X_monotone_curve_2 c = split2;
// split2 = curve_opposite(split1);
// split1 = curve_opposite(c);
// }// end flip
}
// expand (split) the segment[p1, p2] from the curve cv
// X_monotone_curve_2 curve_portion(const X_monotone_curve_2 & cv,
// const Point_2 & p1, const Point_2 & p2)
// {
// CGAL_assertion(!point_equal(p1, p2));
// // direct cv as p1-->p2
// X_monotone_curve_2 acv = cv;
// bool p1_p2_right;//start flip
// bool curve_right;
// Point_2 ap1=p1, ap2=p2;
// p1_p2_right = point_is_left_low(p1, p2);
// curve_right = point_is_left_low(curve_source(cv), curve_target(cv));
// if (curve_right != p1_p2_right) {
// acv = curve_opposite(cv);//end flip
// // ap1 = p2;
// // ap2 = p1;
// }
// // split twice to find the portion [ap1, ap2]
// X_monotone_curve_2 split1, split2, split3, part_cv;
// CGAL_assertion(!point_equal(curve_target(acv), ap1));
// if (point_equal(curve_source(acv), ap1))
// split2 = acv;
// else
// directed_curve_split(acv, curve_source(acv), ap1, split1, split2);
// CGAL_assertion(!point_equal(curve_source(split2), ap2));
// if (point_equal(curve_target(split2), ap2))
// part_cv = split2;
// else
// directed_curve_split(split2, curve_source(split2), ap2, part_cv,
//split3);
// return part_cv;
// }
void points_swap(Point_2 & p1, Point_2 & p2)
{
Point_2 p = p1;
p1 = p2;
p2 = p;
}
// maps the curves to their mirror images over the y coordinate
// and calls nearest_intersect_to_right (see there).
bool nearest_intersection_to_left(const X_monotone_curve_2 & cv1,
const X_monotone_curve_2 & cv2,
const Point_2 & pt,
Point_2 & p1, Point_2 & p2) const
{
return nearest_intersection_to_left_imp(cv1, cv2, pt, p1, p2,
Has_left_category());
}
bool nearest_intersection_to_left_imp(const X_monotone_curve_2 & cv1,
const X_monotone_curve_2 & cv2,
const Point_2 & pt,
Point_2 & p1, Point_2 & p2,
Tag_true) const
{ return Base::nearest_intersection_to_left(cv1, cv2, pt, p1, p2); }
bool nearest_intersection_to_left_imp(const X_monotone_curve_2 & cv1,
const X_monotone_curve_2 & cv2,
const Point_2 & pt,
Point_2 & p1, Point_2 & p2,
Tag_false) const
{
Point_2 rpt = point_reflect_in_x_and_y( pt);
X_monotone_curve_2 rcv1 = curve_reflect_in_x_and_y( cv1);
X_monotone_curve_2 rcv2 = curve_reflect_in_x_and_y( cv2);
Point_2 rp1, rp2;
bool result = nearest_intersection_to_right(rcv1, rcv2, rpt, rp1, rp2);
p1 = point_reflect_in_x_and_y( rp1);
p2 = point_reflect_in_x_and_y( rp2);
return result;
}
};
CGAL_END_NAMESPACE
#endif