mirror of https://github.com/CGAL/cgal
77 lines
2.1 KiB
C++
77 lines
2.1 KiB
C++
// Copyright (c) 1999
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// Utrecht University (The Netherlands),
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// ETH Zurich (Switzerland),
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// INRIA Sophia-Antipolis (France),
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// Max-Planck-Institute Saarbruecken (Germany),
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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) : Sven Schoenherr
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// Stefan Schirra
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#ifndef CGAL_BASIC_CONSTRUCTIONSH2_H
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#define CGAL_BASIC_CONSTRUCTIONSH2_H
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#include <CGAL/Homogeneous/PointH2.h>
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#include <CGAL/Homogeneous/LineH2.h>
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namespace CGAL {
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template <class R>
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CGAL_KERNEL_MEDIUM_INLINE
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typename R::Point_2
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gp_linear_intersection(const LineH2<R>& l1, const LineH2<R>& l2)
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{
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return typename R::Point_2( l1.b()*l2.c() - l2.b()*l1.c(),
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l2.a()*l1.c() - l1.a()*l2.c(),
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l1.a()*l2.b() - l2.a()*l1.b() );
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}
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template <class R>
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CGAL_KERNEL_MEDIUM_INLINE
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typename R::FT
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squared_distance( 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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typedef typename R::FT FT;
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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 sq_dist_numerator =
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phx * phx * qhw * qhw
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- RT(2) * phx * qhx * phw * qhw
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+ qhx * qhx * phw * phw
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+ phy * phy * qhw * qhw
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- RT(2) * phy * qhy * phw * qhw
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+ qhy * qhy * phw * phw ;
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RT sq_dist_denominator = qhw * qhw * phw * phw ;
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return FT( sq_dist_numerator ) / FT( sq_dist_denominator );
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}
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} //namespace CGAL
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#endif // CGAL_BASIC_CONSTRUCTIONSH2_H
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