mirror of https://github.com/CGAL/cgal
98 lines
3.2 KiB
C++
98 lines
3.2 KiB
C++
// Copyright (c) 1999 INRIA Sophia-Antipolis (France).
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// All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org).
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// You can redistribute it and/or modify it under the terms of the GNU
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// General Public License as published by the Free Software Foundation,
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// either version 3 of the License, or (at your option) any later version.
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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) : Sylvain Pion
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// Mariette Yvinec <Mariette.Yvinec@sophia.inria.fr>
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#ifndef CGAL_REGULAR_TRIANGULATION_FTC2_H
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#define CGAL_REGULAR_TRIANGULATION_FTC2_H
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#include <CGAL/number_utils.h>
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// This file contains the low level cartesian predicates
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// used by the 2D regular triangulation.
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namespace CGAL {
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template <class FT>
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Comparison_result
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compare_power_distanceC2(const FT& px, const FT& py, const FT& pwt,
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const FT& qx, const FT& qy, const FT& qwt,
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const FT& rx, const FT& ry)
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{
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// returns SMALLER if r is closer to p w.r.t. the power metric
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FT d1 = CGAL_NTS square(rx - px) + CGAL_NTS square(ry - py) - pwt;
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FT d2 = CGAL_NTS square(rx - qx) + CGAL_NTS square(ry - qy) - qwt;
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return CGAL_NTS compare(d1, d2);
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}
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template <class FT>
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Oriented_side
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power_testC2( const FT &px, const FT &py, const FT &pwt,
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const FT &qx, const FT &qy, const FT &qwt,
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const FT &rx, const FT &ry, const FT &rwt,
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const FT &tx, const FT &ty, const FT &twt)
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{
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// Note: maybe this can be further optimized like the usual in_circle() ?
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// We translate the 4 points so that T becomes the origin.
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FT dpx = px - tx;
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FT dpy = py - ty;
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FT dpz = CGAL_NTS square(dpx) + CGAL_NTS square(dpy) - pwt + twt;
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FT dqx = qx - tx;
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FT dqy = qy - ty;
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FT dqz = CGAL_NTS square(dqx) + CGAL_NTS square(dqy) - qwt + twt;
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FT drx = rx - tx;
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FT dry = ry - ty;
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FT drz = CGAL_NTS square(drx) + CGAL_NTS square(dry) - rwt + twt;
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return sign_of_determinant(dpx, dpy, dpz,
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dqx, dqy, dqz,
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drx, dry, drz);
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}
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template <class FT>
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Oriented_side
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power_testC2( const FT &px, const FT &py, const FT &pwt,
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const FT &qx, const FT &qy, const FT &qwt,
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const FT &tx, const FT &ty, const FT &twt)
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{
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// Same translation as above.
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FT dpx = px - tx;
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FT dpy = py - ty;
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FT dpz = CGAL_NTS square(dpx) + CGAL_NTS square(dpy) - pwt + twt;
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FT dqx = qx - tx;
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FT dqy = qy - ty;
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FT dqz = CGAL_NTS square(dqx) + CGAL_NTS square(dqy) - qwt + twt;
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// We do an orthogonal projection on the (x) axis, if possible.
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Comparison_result cmpx = CGAL_NTS compare(px, qx);
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if (cmpx != EQUAL)
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return cmpx * sign_of_determinant(dpx, dpz, dqx, dqz);
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// If not possible, then on the (y) axis.
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Comparison_result cmpy = CGAL_NTS compare(py, qy);
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return cmpy * sign_of_determinant(dpy, dpz, dqy, dqz);
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}
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} //namespace CGAL
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#endif // CGAL_REGULAR_TRIANGULATION_FTC2_H
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