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/*
This file is part of Warzone 2100.
Copyright (C) 1999-2004 Eidos Interactive
Copyright (C) 2005-2020 Warzone 2100 Project
Warzone 2100 is free software; 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 2 of the License, or
(at your option) any later version.
Warzone 2100 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Warzone 2100; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*!
* \file
* \brief Rational number classes.
*/
#ifndef RATIONAL_H
#define RATIONAL_H
#include <algorithm>
#include <cmath>
static inline int gcd(int a, int b)
{
while (b != 0)
{
a %= b;
std::swap(a, b);
}
return abs(a);
}
/// Simple rational numbers, not bignum.
struct Rational
{
Rational() {}
Rational(int numerator, int denominator = 1)
{
int g = gcd(numerator, denominator);
g *= denominator > 0 ? 1 : -1;
n = numerator / g;
d = denominator / g;
}
bool operator ==(Rational const &b) const
{
return n * b.d == b.n * d;
}
bool operator !=(Rational const &b) const
{
return n * b.d != b.n * d;
}
bool operator < (Rational const &b) const
{
return n * b.d < b.n * d;
}
bool operator <=(Rational const &b) const
{
return n * b.d <= b.n * d;
}
bool operator > (Rational const &b) const
{
return n * b.d > b.n * d;
}
bool operator >=(Rational const &b) const
{
return n * b.d >= b.n * d;
}
Rational operator +(Rational const &b) const
{
return Rational(n * b.d + b.n * d, d * b.d);
}
Rational operator -(Rational const &b) const
{
return Rational(n * b.d - b.n * d, d * b.d);
}
Rational operator *(Rational const &b) const
{
return Rational(n * b.n, d * b.d);
}
Rational operator /(Rational const &b) const
{
return Rational(n * b.d, d * b.n);
}
Rational operator -() const
{
return Rational(-n, d);
}
Rational &operator +=(Rational const &b)
{
return *this = *this + b;
}
Rational &operator -=(Rational const &b)
{
return *this = *this - b;
}
Rational &operator *=(Rational const &b)
{
return *this = *this * b;
}
Rational &operator /=(Rational const &b)
{
return *this = *this / b;
}
int floor() const
{
return n >= 0 ? n / d : (n - (d - 1)) / d;
}
int ceil() const
{
return n >= 0 ? (n + (d - 1)) / d : n / d;
}
// We can't do this with a operator as it ambiguates the comparison operators
double asDouble() const
{
if (0 == d)
{
return nan("");
}
return (double)n / (double)d;
}
// If int16_t isn't big enough, the comparison operations might overflow.
int16_t n;
int16_t d;
private:
Rational(float); // Disable.
Rational(double); // Disable.
};
#endif //RATIONAL_H
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