dust3d/thirdparty/cgal/CGAL-5.1/include/CGAL/RS/comparator_1.h

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3.1 KiB
C++

// Copyright (c) 2006-2013 INRIA Nancy-Grand Est (France). All rights reserved.
//
// This file is part of CGAL (www.cgal.org)
//
// $URL: https://github.com/CGAL/cgal/blob/v5.1/Algebraic_kernel_d/include/CGAL/RS/comparator_1.h $
// $Id: comparator_1.h 52164b1 2019-10-19T15:34:59+02:00 Sébastien Loriot
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
// Author: Luis Peñaranda <luis.penaranda@gmx.com>
#ifndef CGAL_RS_COMPARATOR_1_H
#define CGAL_RS_COMPARATOR_1_H
namespace CGAL{
namespace RS_AK1{
template <class Polynomial_,
class Bound_,
class Refiner_,
class Signat_,
class Ptraits_>
struct Simple_comparator_1{
typedef Polynomial_ Polynomial;
typedef Bound_ Bound;
typedef Refiner_ Refiner;
typedef Signat_ Signat;
typedef Ptraits_ Ptraits;
typedef typename Ptraits::Gcd_up_to_constant_factor Gcd;
typedef typename Ptraits::Degree Degree;
CGAL::Comparison_result
operator()(const Polynomial &p1,Bound &l1,Bound &r1,
const Polynomial &p2,Bound &l2,Bound &r2)const{
CGAL_precondition(l1<=r1&&l2<=r2);
if(l1<=l2){
if(r1<l2)
return SMALLER;
}else{
if(r2<l1)
return LARGER;
}
Polynomial G=Gcd()(p1,p2);
if(Degree()(G)==0)
return compare_unequal(p1,l1,r1,p2,l2,r2);
Signat sg(G);
CGAL::Sign sleft=sg(l1>l2?l1:l2);
if(sleft==ZERO)
return EQUAL;
CGAL::Sign sright=sg(r1<r2?r1:r2);
if(sleft!=sright)
return EQUAL;
else
return compare_unequal(p1,l1,r1,p2,l2,r2);
}
// This function compares two algebraic numbers, assuming that they
// are not equal.
CGAL::Comparison_result
compare_unequal(const Polynomial &p1,Bound &l1,Bound &r1,
const Polynomial &p2,Bound &l2,Bound &r2)const{
CGAL_precondition(l1<=r1&&l2<=r2);
int prec=CGAL::max(
CGAL::max(l1.get_precision(),
r1.get_precision()),
CGAL::max(l2.get_precision(),
r2.get_precision()));
do{
prec*=2;
Refiner()(p1,l1,r1,prec);
Refiner()(p2,l2,r2,prec);
CGAL_assertion(l1<=r1&&l2<=r2);
}while(l1<=l2?r1>=l2:r2>=l1);
return (r1<l2?SMALLER:LARGER);
}
}; // struct Simple_comparator_1
} // namespace RS_AK1
} // namespace CGAL
#endif // CGAL_RS_COMPARATOR_1_H