mirror of https://github.com/CGAL/cgal
108 lines
2.9 KiB
C++
108 lines
2.9 KiB
C++
// Copyright (c) 1999 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) : Stefan Schirra
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#ifndef CGAL_PREDICATES_ON_POINTSH2_H
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#define CGAL_PREDICATES_ON_POINTSH2_H
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#include <CGAL/Homogeneous/PointH2.h>
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CGAL_BEGIN_NAMESPACE
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template < class R>
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CGAL_KERNEL_INLINE
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bool
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equal_xy(const PointH2<R>& p,
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const PointH2<R>& q)
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{
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typedef typename R::RT RT;
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// Using these references allows to spare calls to [pq].hw().
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const RT& phw = p.hw();
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const RT& qhw = q.hw();
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return (p.hx()*qhw == q.hx()*phw) && (p.hy()*qhw == q.hy()*phw);
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}
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template < class R>
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CGAL_KERNEL_INLINE
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Comparison_result
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compare_yx(const PointH2<R>& p, const PointH2<R>& q)
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{
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typedef typename R::RT RT;
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const RT& phx = p.hx();
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const RT& phy = p.hy();
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const RT& phw = p.hw();
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const RT& qhx = q.hx();
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const RT& qhy = q.hy();
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const RT& qhw = q.hw();
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RT pV = phy*qhw;
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RT qV = qhy*phw;
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if ( pV == qV )
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{
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pV = phx*qhw;
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qV = qhx*phw;
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}
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if ( pV < qV )
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return SMALLER;
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else
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return ( qV < pV ) ? LARGER : EQUAL;
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}
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template <class R>
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CGAL_KERNEL_MEDIUM_INLINE
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Oriented_side
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_where_wrt_L_wedge( const PointH2<R>& p, const PointH2<R>& q )
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{
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Sign xs = CGAL_NTS sign( q.hx()*p.hw() - p.hx()*q.hw() ); // sign( qx - px )
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Sign ys = CGAL_NTS sign( q.hy()*p.hw() - p.hy()*q.hw() ); // sign( qy - py )
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if (( xs == NEGATIVE ) || ( ys == NEGATIVE ))
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return ON_NEGATIVE_SIDE;
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if (( xs == POSITIVE ) && ( ys == POSITIVE ))
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return ON_POSITIVE_SIDE;
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return ON_ORIENTED_BOUNDARY;
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}
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#if 0
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// Unused, undocumented, un-functorized.
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template < class R >
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CGAL_KERNEL_MEDIUM_INLINE
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Comparison_result
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compare_deltax_deltay(const PointH2<R>& p,
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const PointH2<R>& q,
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const PointH2<R>& r,
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const PointH2<R>& s)
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{
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return CGAL_NTS compare(
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CGAL_NTS abs(p.hx()*q.hw() - q.hx()*p.hw()) * r.hw()*s.hw(),
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CGAL_NTS abs(r.hy()*s.hw() - s.hy()*r.hw()) * p.hw()*q.hw());
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}
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#endif
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CGAL_END_NAMESPACE
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#endif // CGAL_PREDICATES_ON_POINTSH2_H
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