functions.hpp

#ifndef H_EXTENSIONS_CUTEHMI_2_INCLUDE_CUTEHMI_FUNCTIONS_HPP
#define H_EXTENSIONS_CUTEHMI_2_INCLUDE_CUTEHMI_FUNCTIONS_HPP
 
#include "constants.hpp"
 
#include <cmath>
 
namespace cutehmi {
 
inline
bool ape(qreal r1, qreal r2, qreal eps = EPS)
{
    int exp1, exp2;
    std::frexp(r1, & exp1);
    std::frexp(r2, & exp2);
 
    // For some reason <= is used in the book to compare both sides. There may be a reason for this, so I'll leave it for now, but
    // the consequence is that image of a function is a bit weird, e.g.:
    // ape(1.0, 1.99, 0.25) -> false, ape(1.0, 2.0, 0.25) -> true, ape(1.0, 2.01, 0.25) -> false
    return std::abs(r2 - r1) <= std::ldexp(eps, std::max(exp1, exp2));
}
 
inline
bool ale(qreal r1, qreal r2, qreal eps = EPS)
{
    int exp1, exp2;
    std::frexp(r1, & exp1);
    std::frexp(r2, & exp2);
 
    return std::abs(r2 - r1) <= std::ldexp(eps, std::min(exp1, exp2));
}
 
inline
bool clt(qreal r1, qreal r2, qreal eps = EPS)
{
    int exp1, exp2;
    std::frexp(r1, & exp1);
    std::frexp(r2, & exp2);
 
    return r2 - r1 > std::ldexp(eps, std::max(exp1, exp2));
}
 
inline
bool cgt(qreal r1, qreal r2, qreal eps = EPS)
{
    int exp1, exp2;
    std::frexp(r1, & exp1);
    std::frexp(r2, & exp2);
 
    return r1 - r2 > std::ldexp(eps, std::max(exp1, exp2));
}
 
}
 
#endif
 
//(c)C: Copyright © 2019, Michał Policht <michal@policht.pl>. All rights reserved.
//(c)C: This file is a part of CuteHMI.
//(c)C: CuteHMI is free software: 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.
//(c)C: CuteHMI is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
//(c)C: You should have received a copy of the GNU Lesser General Public License along with CuteHMI.  If not, see <https://www.gnu.org/licenses/>.