83 lines
2.5 KiB
C++
83 lines
2.5 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)
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//
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// $URL: https://github.com/CGAL/cgal/blob/v5.1/Homogeneous_kernel/include/CGAL/Homogeneous/basic_constructionsH3.h $
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// $Id: basic_constructionsH3.h 0779373 2020-03-26T13:31:46+01:00 Sébastien Loriot
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// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
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//
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//
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// Author(s) : Stefan Schirra
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#ifndef CGAL_BASIC_CONSTRUCTIONSH3_H
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#define CGAL_BASIC_CONSTRUCTIONSH3_H
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#include <CGAL/Cartesian/Point_3.h>
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#include <CGAL/Cartesian/Plane_3.h>
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namespace CGAL {
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template <class R>
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typename R::Point_3
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_projection(const typename R::Point_3& p, const PlaneH3<R>& pl)
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{
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typedef typename R::RT RT;
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if ( pl.has_on(p) ) return p;
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RT A = pl.a();
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RT B = pl.b();
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RT C = pl.c();
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RT D = pl.d();
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RT phx = p.hx();
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RT phy = p.hy();
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RT phz = p.hz();
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RT phw = p.hw();
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RT num = A * phx + B * phy + C * phz + D * phw;
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RT den = A * A + B * B + C * C;
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return typename R::Point_3( num * A - den * phx,
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num * B - den * phy,
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num * C - den * phz,
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-den );
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}
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template <class R>
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typename R::Point_3
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gp_linear_intersection(const PlaneH3<R> &f,
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const PlaneH3<R> &g,
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const PlaneH3<R> &h)
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{
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typedef typename R::RT RT;
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return typename R::Point_3(
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determinant<RT>(-f.d(), f.b(), f.c(),
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-g.d(), g.b(), g.c(),
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-h.d(), h.b(), h.c()),
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determinant<RT>( f.a(),-f.d(), f.c(),
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g.a(),-g.d(), g.c(),
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h.a(),-h.d(), h.c()),
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determinant<RT>( f.a(), f.b(),-f.d(),
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g.a(), g.b(),-g.d(),
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h.a(), h.b(),-h.d()),
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determinant<RT>( f.a(), f.b(), f.c(),
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g.a(), g.b(), g.c(),
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h.a(), h.b(), h.c()));
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}
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template <class R>
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CGAL_KERNEL_INLINE
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typename R::FT
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squared_distance( PointH3<R> const& p, PointH3<R> const& q)
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{ return (p-q)*(p-q); }
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} //namespace CGAL
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#endif // CGAL_BASIC_CONSTRUCTIONSH3_H
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