dust3d/thirdparty/cgal/CGAL-4.13/include/CGAL/RS/exact_signat_1.h

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// Copyright (c) 2006-2013 INRIA Nancy-Grand Est (France). All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 3 of the License,
// or (at your option) any later version.
// See the file LICENSE.LGPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
// SPDX-License-Identifier: LGPL-3.0+
//
// Author: Luis Peñaranda <luis.penaranda@gmx.com>
#ifndef CGAL_RS_EXACT_SIGNAT_1_H
#define CGAL_RS_EXACT_SIGNAT_1_H
#include <CGAL/Polynomial_traits_d.h>
#include "dyadic.h"
namespace CGAL{
namespace RS_AK1{
template <class Polynomial_,class Bound_>
struct ExactSignat_1{
typedef Polynomial_ Polynomial;
typedef Bound_ Bound;
typedef CGAL::Polynomial_traits_d<Polynomial> PT;
typedef typename PT::Degree Degree;
Polynomial pol;
ExactSignat_1(const Polynomial &p):pol(p){};
CGAL::Sign operator()(const Bound&)const;
}; // struct ExactSignat_1
template <>
inline CGAL::Sign
ExactSignat_1<Polynomial<Gmpz>,Gmpfr>::operator()(const Gmpfr &x)const{
int d=Degree()(pol);
if(d==0)
return pol[0].sign();
// Construct a Gmpfr containing exactly the leading coefficient.
Gmpfr h(pol[d],pol[d].bit_size());
CGAL_assertion(h==pol[d]);
// Horner's evaluation.
for(int i=1;i<d;++i){
CGALRS_dyadic_mul(h.fr(),h.fr(),x.fr());
CGALRS_dyadic_add_z(h.fr(),h.fr(),pol[d-i].mpz());
}
// TODO: We can avoid doing the last addition.
return h.sign();
}
} // namespace RS_AK1
} // namespace CGAL
#endif // CGAL_RS_EXACT_SIGNAT_1_H