mirror of https://github.com/CGAL/cgal
247 lines
6.0 KiB
C++
247 lines
6.0 KiB
C++
// ============================================================================
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//
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// Copyright (c) 1998 The CGAL Consortium
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//
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// This software and related documentation is part of an INTERNAL release
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// of the Computational Geometry Algorithms Library (CGAL). It is not
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// intended for general use.
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//
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// ----------------------------------------------------------------------------
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//
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// release : $CGAL_Revision: $
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// release_date : $CGAL_Date: $
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//
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// file : include/CGAL/squared_distance_utils.h
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// source : sqdistance_2.fw
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// author(s) : Geert-Jan Giezeman
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//
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// coordinator : Saarbruecken
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//
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// ============================================================================
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#ifndef CGAL_SQUARED_DISTANCE_UTILS_H
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#define CGAL_SQUARED_DISTANCE_UTILS_H
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#include <CGAL/determinant.h>
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#include <CGAL/wmult.h>
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CGAL_BEGIN_NAMESPACE
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namespace CGALi {
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template <class K>
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bool is_null(const typename CGAL_WRAP(K)::Vector_2 &v, const K&)
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{
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typedef typename K::RT RT;
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return v.hx()==RT(0) && v.hy()==RT(0);
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}
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template <class K>
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typename K::RT
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wdot(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K&)
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{
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return (u.hx()*v.hx() + u.hy()*v.hy());
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}
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template <class K>
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typename K::RT wdot(const typename CGAL_WRAP(K)::Point_2 &p,
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const typename CGAL_WRAP(K)::Point_2 &q,
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const typename CGAL_WRAP(K)::Point_2 &r,
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const K&)
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{
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K* pR = 0;
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return (wmult(pR, p.hx(),q.hw()) - wmult(pR, q.hx(),p.hw()))
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* (wmult(pR, r.hx(),q.hw()) - wmult(pR, q.hx(),r.hw()))
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+ (wmult(pR, p.hy(),q.hw()) - wmult(pR, q.hy(),p.hw()))
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* (wmult(pR, r.hy(),q.hw()) - wmult(pR, q.hy(),r.hw()));
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}
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template <class K>
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typename K::RT
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wcross(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K&)
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{
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return (typename K::RT)(u.hx()*v.hy() - u.hy()*v.hx());
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}
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template <class K>
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inline
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typename K::RT
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wcross_tag(const typename CGAL_WRAP(K)::Point_2 &p,
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const typename CGAL_WRAP(K)::Point_2 &q,
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const typename CGAL_WRAP(K)::Point_2 &r,
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const K&,
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const Homogeneous_tag&)
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{
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return det3x3_by_formula(
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p.hx(), q.hx(), r.hx(),
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p.hy(), q.hy(), r.hy(),
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p.hw(), q.hw(), r.hw());
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}
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template <class K>
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inline
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typename K::FT
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wcross_tag(const typename CGAL_WRAP(K)::Point_2 &p,
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const typename CGAL_WRAP(K)::Point_2 &q,
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const typename CGAL_WRAP(K)::Point_2 &r,
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const K&,
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const Cartesian_tag&)
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{
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return (q.x()-p.x())*(r.y()-q.y()) - (q.y()-p.y())*(r.x()-q.x());
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}
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template <class K>
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typename K::RT wcross(const typename CGAL_WRAP(K)::Point_2 &p,
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const typename CGAL_WRAP(K)::Point_2 &q,
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const typename CGAL_WRAP(K)::Point_2 &r,
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const K& k)
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{
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typedef typename K::Kernel_tag Tag;
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Tag tag;
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return wcross_tag(p, q, r, k, tag);
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}
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template <class K>
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inline bool is_acute_angle(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wdot(u, v, k)) > RT(0) ;
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}
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template <class K>
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inline bool is_straight_angle(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wdot(u, v, k)) == RT(0) ;
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}
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template <class K>
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inline bool is_obtuse_angle(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wdot(u, v, k)) < RT(0) ;
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}
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template <class K>
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inline bool is_acute_angle(const typename CGAL_WRAP(K)::Point_2 &p,
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const typename CGAL_WRAP(K)::Point_2 &q,
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const typename CGAL_WRAP(K)::Point_2 &r,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wdot(p, q, r, k)) > RT(0) ;
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}
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template <class K>
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inline bool is_straight_angle(const typename CGAL_WRAP(K)::Point_2 &p,
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const typename CGAL_WRAP(K)::Point_2 &q,
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const typename CGAL_WRAP(K)::Point_2 &r,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wdot(p, q, r, k)) == RT(0) ;
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}
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template <class K>
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inline bool is_obtuse_angle(const typename CGAL_WRAP(K)::Point_2 &p,
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const typename CGAL_WRAP(K)::Point_2 &q,
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const typename CGAL_WRAP(K)::Point_2 &r,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wdot(p, q, r, k)) < RT(0) ;
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}
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template <class K>
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Orientation orientation(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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RT wcr = wcross(u,v, k);
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return (wcr > RT(0)) ? COUNTERCLOCKWISE :
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(wcr < RT(0)) ? CLOCKWISE
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: COLLINEAR;
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}
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template <class K>
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inline bool counterclockwise(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wcross(u,v, k)) > RT(0);
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}
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template <class K>
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inline bool left_turn(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wcross(u,v, k)) > RT(0);
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}
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template <class K>
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inline bool clockwise(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wcross(u,v, k)) < RT(0);
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}
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template <class K>
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inline bool right_turn(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wcross(u,v, k)) < RT(0);
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}
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template <class K>
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inline bool collinear(const typename CGAL_WRAP(K)::Vector_2 &u,
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const typename CGAL_WRAP(K)::Vector_2 &v,
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const K& k)
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{
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typedef typename K::RT RT;
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return RT(wcross(u,v, k)) == RT(0);
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}
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/*
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the ordertype, right_turn, left_turn and collinear routines for points are
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defined elsewhere.
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*/
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} // namespace CGALi
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CGAL_END_NAMESPACE
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#endif // CGAL_SQUARED_DISTANCE_UTILS_H
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