/usr/include/CGAL/functions_on_signs.h is in libcgal-dev 4.11-2build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 | // Copyright (c) 2003 INRIA Sophia-Antipolis (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
// General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// 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.
//
// $URL$
// $Id$
//
//
// Author(s) : Menelaos Karavelas <mkaravel@iacm.forth.gr>
#ifndef CGAL_FUNCTIONS_ON_SIGNS_H
#define CGAL_FUNCTIONS_ON_SIGNS_H
#include <CGAL/license/Apollonius_graph_2.h>
#include <CGAL/enum.h>
#include <CGAL/number_utils.h>
namespace CGAL {
#if 0
inline
Sign
operator*(const Sign &s1, const Sign &s2)
{
if ( s1 == ZERO || s2 == ZERO ) return ZERO;
if ( s1 == s2 ) return POSITIVE;
return NEGATIVE;
}
#endif
template < class RT >
Sign
sign_a_plus_b_x_sqrt_c(const RT &a, const RT &b, const RT &c)
{
// computes the sign of quantity: a + b * sqrt(c)
CGAL_assertion( !(CGAL::is_negative(c)) );
Sign sa = CGAL::sign(a);
if ( CGAL::sign(c) == ZERO ) return sa;
Sign sb = CGAL::sign(b);
if ( sa == sb ) return sa;
if ( sa == ZERO ) return sb;
return sa * CGAL::compare( CGAL::square(a),
c * CGAL::square(b) );
}
template < class RT >
Sign
sign_a_x_sqrt_c_plus_b_x_sqrt_d(const RT &a, const RT &b,
const RT &c, const RT &d)
{
// computes the sign of quantity: a * sqrt(c) + b * sqrt(d)
CGAL_assertion( !(CGAL::is_negative(c)) );
CGAL_assertion( !(CGAL::is_negative(d)) );
Sign sb = CGAL::sign(b);
if ( CGAL::sign(d) == ZERO ) return CGAL::sign(a * c);
if ( CGAL::sign(c) == ZERO ) return sb;
Sign sa = CGAL::sign(a);
if ( sa == sb ) return sa;
if ( sa == ZERO ) return sb;
return sa * CGAL::compare( CGAL::square(a) * c,
CGAL::square(b) * d );
}
template < class RT >
Sign
sign_a_plus_b_x_sqrt_e_plus_c_x_sqrt_f(const RT &a, const RT &b,
const RT &c, const RT &e,
const RT &f)
{
// computes the sign of quantity: a + b * sqrt(e) + c * sqrt(f)
CGAL_assertion( !(CGAL::is_negative(e)) );
CGAL_assertion( !(CGAL::is_negative(f)) );
Sign s_a_plus_b_x_sqrt_e = sign_a_plus_b_x_sqrt_c(a, b, e);
if ( CGAL::sign(f) == ZERO ) return s_a_plus_b_x_sqrt_e;
Sign sc = CGAL::sign(c);
if ( s_a_plus_b_x_sqrt_e == sc ) return sc;
if ( s_a_plus_b_x_sqrt_e == ZERO ) return sc;
return s_a_plus_b_x_sqrt_e *
sign_a_plus_b_x_sqrt_c(CGAL::square(a) + CGAL::square(b) * e
- CGAL::square(c) * f,
RT(2) * a * b, e);
}
template < class RT >
Sign
sign_a_plus_b_x_sqrt_e_plus_c_x_sqrt_f_plus_d_sqrt_e_x_f(const RT &a,
const RT &b,
const RT &c,
const RT &d,
const RT &e,
const RT &f)
{
// computes the sign of quantity:
// a + b * sqrt(e) + c * sqrt(f) + d * sqrt(e * f)
CGAL_assertion( !(CGAL::is_negative(e)) );
CGAL_assertion( !(CGAL::is_negative(f)) );
Sign s_a_plus_b_sqrt_e = sign_a_plus_b_x_sqrt_c(a, b, e);
Sign s_c_plus_d_sqrt_e = sign_a_plus_b_x_sqrt_c(c, d, e);
if ( s_a_plus_b_sqrt_e == s_c_plus_d_sqrt_e )
return s_a_plus_b_sqrt_e;
if ( s_a_plus_b_sqrt_e == ZERO )
return s_a_plus_b_sqrt_e;
return s_a_plus_b_sqrt_e *
sign_a_plus_b_x_sqrt_c(CGAL::square(a) + CGAL::square(b) * e
- CGAL::square(c) * f
- CGAL::square(d) * e * f,
RT(2) * (a * b - c * d * f),
e);
}
} //namespace CGAL
#include <CGAL/more_functions_on_signs.h>
#endif // CGAL_FUNCTIONS_ON_SIGNS_H
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