Files
libopenshot/src/Fraction.cpp
2021-08-10 23:47:18 -04:00

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2.7 KiB
C++

/**
* @file
* @brief Source file for Fraction class
* @author Jonathan Thomas <jonathan@openshot.org>
*
* @ref License
*/
/* LICENSE
*
* Copyright (c) 2008-2019 OpenShot Studios, LLC
* <http://www.openshotstudios.com/>. This file is part of
* OpenShot Library (libopenshot), an open-source project dedicated to
* delivering high quality video editing and animation solutions to the
* world. For more information visit <http://www.openshot.org/>.
*
* OpenShot Library (libopenshot) 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.
*
* OpenShot Library (libopenshot) 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.
*
* You should have received a copy of the GNU Lesser General Public License
* along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "Fraction.h"
#include <cmath>
using namespace openshot;
// Delegating constructors
Fraction::Fraction() : Fraction::Fraction(1, 1) {}
Fraction::Fraction(std::pair<int, int> pair)
: Fraction::Fraction(pair.first, pair.second) {}
Fraction::Fraction(std::map<std::string, int> mapping)
: Fraction::Fraction(mapping["num"], mapping["den"]) {}
Fraction::Fraction(std::vector<int> vector)
: Fraction::Fraction(vector[0], vector[1]) {}
// Full constructor
Fraction::Fraction(int num, int den) :
num(num), den(den) {}
// Return this fraction as a float (i.e. 1/2 = 0.5)
float Fraction::ToFloat() {
return float(num) / float(den);
}
// Return this fraction as a double (i.e. 1/2 = 0.5)
double Fraction::ToDouble() const {
return double(num) / double(den);
}
// Return a rounded integer of the frame rate (for example 30000/1001 returns 30 fps)
int Fraction::ToInt() {
return round((double) num / den);
}
// Calculate the greatest common denominator
int Fraction::GreatestCommonDenominator() {
int first = num;
int second = den;
// Find the biggest whole number that will divide into both the numerator
// and denominator
int t;
while (second != 0) {
t = second;
second = first % second;
first = t;
}
return first;
}
void Fraction::Reduce() {
// Get the greatest common denominator
int GCD = GreatestCommonDenominator();
// Reduce this fraction to the smallest possible whole numbers
num = num / GCD;
den = den / GCD;
}
// Return the reciprocal as a new Fraction
Fraction Fraction::Reciprocal() const
{
// flip the fraction
return Fraction(den, num);
}