mirror of https://github.com/axmolengine/axmol.git
48 lines
1.1 KiB
C
48 lines
1.1 KiB
C
|
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
||
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
||
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
||
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
||
|
|
|
||
|
|
/* mfbt maths algorithms. */
|
||
|
|
|
||
|
|
#ifndef mozilla_MathAlgorithms_h_
|
||
|
|
#define mozilla_MathAlgorithms_h_
|
||
|
|
|
||
|
|
#include "mozilla/Assertions.h"
|
||
|
|
|
||
|
|
namespace mozilla {
|
||
|
|
|
||
|
|
// Greatest Common Divisor
|
||
|
|
template<typename IntegerType>
|
||
|
|
MOZ_ALWAYS_INLINE IntegerType
|
||
|
|
EuclidGCD(IntegerType a, IntegerType b)
|
||
|
|
{
|
||
|
|
// Euclid's algorithm; O(N) in the worst case. (There are better
|
||
|
|
// ways, but we don't need them for the current use of this algo.)
|
||
|
|
MOZ_ASSERT(a > 0);
|
||
|
|
MOZ_ASSERT(b > 0);
|
||
|
|
|
||
|
|
while (a != b) {
|
||
|
|
if (a > b) {
|
||
|
|
a = a - b;
|
||
|
|
} else {
|
||
|
|
b = b - a;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return a;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Least Common Multiple
|
||
|
|
template<typename IntegerType>
|
||
|
|
MOZ_ALWAYS_INLINE IntegerType
|
||
|
|
EuclidLCM(IntegerType a, IntegerType b)
|
||
|
|
{
|
||
|
|
// Divide first to reduce overflow risk.
|
||
|
|
return (a / EuclidGCD(a, b)) * b;
|
||
|
|
}
|
||
|
|
|
||
|
|
} /* namespace mozilla */
|
||
|
|
|
||
|
|
#endif /* mozilla_MathAlgorithms_h_ */
|