OpenShot Library | libopenshot 0.2.7
Fraction.h
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1/**
2 * @file
3 * @brief Header file for Fraction class
4 * @author Jonathan Thomas <jonathan@openshot.org>
5 *
6 * @ref License
7 */
8
9/* LICENSE
10 *
11 * Copyright (c) 2008-2019 OpenShot Studios, LLC
12 * <http://www.openshotstudios.com/>. This file is part of
13 * OpenShot Library (libopenshot), an open-source project dedicated to
14 * delivering high quality video editing and animation solutions to the
15 * world. For more information visit <http://www.openshot.org/>.
16 *
17 * OpenShot Library (libopenshot) is free software: you can redistribute it
18 * and/or modify it under the terms of the GNU Lesser General Public License
19 * as published by the Free Software Foundation, either version 3 of the
20 * License, or (at your option) any later version.
21 *
22 * OpenShot Library (libopenshot) is distributed in the hope that it will be
23 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU Lesser General Public License for more details.
26 *
27 * You should have received a copy of the GNU Lesser General Public License
28 * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
29 */
30
31#ifndef OPENSHOT_FRACTION_H
32#define OPENSHOT_FRACTION_H
33
34#include <string> // for std::string
35#include <utility> // for std::pair
36#include <map> // for std::map
37#include <vector> // for std::vector
38
39namespace openshot {
40
41 /**
42 * @brief This class represents a fraction
43 *
44 * Fractions are often used in video editing to represent ratios and rates, for example:
45 * pixel ratios, frames per second, timebase, and other common ratios. Fractions are preferred
46 * over decimals due to their increased precision.
47 */
48 class Fraction {
49 public:
50 int num; ///<Numerator for the fraction
51 int den; ///<Denominator for the fraction
52
53 /// Default Constructor
54 Fraction();
55
56 /// Constructor with numerator and denominator
57 Fraction(int num, int den);
58
59 /// Constructor that accepts a (num, den) pair
60 Fraction(std::pair<int, int> pair);
61
62 /// Constructor that takes a vector of length 2 (containing {num, den})
63 Fraction(std::vector<int> vector);
64
65 /// Constructor that takes a key-value mapping (keys: 'num'. 'den')
66 Fraction(std::map<std::string, int> mapping);
67
68 /// Calculate the greatest common denominator
70
71 /// Reduce this fraction (i.e. 640/480 = 4/3)
72 void Reduce();
73
74 /// Return this fraction as a float (i.e. 1/2 = 0.5)
75 float ToFloat();
76
77 /// Return this fraction as a double (i.e. 1/2 = 0.5)
78 double ToDouble() const;
79
80 /// Return a rounded integer of the fraction (for example 30000/1001 returns 30)
81 int ToInt();
82
83 /// Return the reciprocal as a Fraction
84 Fraction Reciprocal() const;
85 };
86
87
88}
89
90#endif
This class represents a fraction.
Definition: Fraction.h:48
int num
Numerator for the fraction.
Definition: Fraction.h:50
Fraction()
Default Constructor.
Definition: Fraction.cpp:37
float ToFloat()
Return this fraction as a float (i.e. 1/2 = 0.5)
Definition: Fraction.cpp:54
double ToDouble() const
Return this fraction as a double (i.e. 1/2 = 0.5)
Definition: Fraction.cpp:59
void Reduce()
Reduce this fraction (i.e. 640/480 = 4/3)
Definition: Fraction.cpp:84
int ToInt()
Return a rounded integer of the fraction (for example 30000/1001 returns 30)
Definition: Fraction.cpp:64
Fraction Reciprocal() const
Return the reciprocal as a Fraction.
Definition: Fraction.cpp:94
int GreatestCommonDenominator()
Calculate the greatest common denominator.
Definition: Fraction.cpp:69
int den
Denominator for the fraction.
Definition: Fraction.h:51
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:47