mirror of https://github.com/CGAL/cgal
310 lines
7.0 KiB
C++
310 lines
7.0 KiB
C++
// Copyright (c) 1998 Utrecht University (The Netherlands),
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// ETH Zurich (Switzerland), Freie Universitaet Berlin (Germany),
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// INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
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// (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
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// and Tel-Aviv University (Israel). All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public License as
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// published by the Free Software Foundation; version 2.1 of the License.
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// See the file LICENSE.LGPL distributed with CGAL.
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//
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// Licensees holding a valid commercial license may use this file in
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// accordance with the commercial license agreement provided with the software.
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//
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// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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//
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// $URL$
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// $Id$
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//
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//
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// Author(s) : Geert-Jan Giezeman
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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 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 K::Vector_2 &u,
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const typename 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_tag(const typename K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 (p.x() - q.x()) * (r.x() - q.x())
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+ (p.y() - q.y()) * (r.y() - q.y());
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}
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template <class K>
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typename K::RT wdot_tag(const typename K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 (p.hx() * q.hw() - q.hx() * p.hw())
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* (r.hx() * q.hw() - q.hx() * r.hw())
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+ (p.hy() * q.hw() - q.hy() * p.hw())
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* (r.hy() * q.hw() - q.hy() * r.hw());
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}
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template <class K>
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typename K::RT wdot(const typename K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 wdot_tag(p, q, r, k, tag);
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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 K::Vector_2 &u,
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const typename 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 K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 K::Vector_2 &u,
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const typename 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 K::Vector_2 &u,
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const typename 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 K::Vector_2 &u,
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const typename 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 K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 K::Point_2 &p,
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const typename K::Point_2 &q,
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const typename 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 counterclockwise(const typename K::Vector_2 &u,
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const typename 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 K::Vector_2 &u,
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const typename 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 K::Vector_2 &u,
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const typename 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 K::Vector_2 &u,
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const typename 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 K::Vector_2 &u,
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const typename 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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template <class K>
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inline
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bool
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same_direction_tag(const typename K::Vector_2 &u,
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const typename K::Vector_2 &v,
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const K&,
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const Cartesian_tag&)
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{
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typedef typename K::FT FT;
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const FT& ux = u.x();
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const FT& uy = u.y();
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if (CGAL_NTS abs(ux) > CGAL_NTS abs(uy)) {
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return CGAL_NTS sign(ux) == CGAL_NTS sign(v.x());
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} else {
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return CGAL_NTS sign(uy) == CGAL_NTS sign(v.y());
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}
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}
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template <class K>
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inline
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bool
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same_direction_tag(const typename K::Vector_2 &u,
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const typename K::Vector_2 &v,
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const K&,
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const Homogeneous_tag&)
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{
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typedef typename K::RT RT;
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const RT& uhx = u.hx();
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const RT& uhy = u.hy();
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if (CGAL_NTS abs(uhx) > CGAL_NTS abs(uhy)) {
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return CGAL_NTS sign(uhx) == CGAL_NTS sign(v.hx());
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} else {
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return CGAL_NTS sign(uhy) == CGAL_NTS sign(v.hy());
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}
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}
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template <class K>
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inline
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bool
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same_direction(const typename K::Vector_2 &u,
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const typename K::Vector_2 &v,
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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 same_direction_tag(u,v, k, tag);
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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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