mirror of
https://github.com/cocos/cocos-engine.git
synced 2026-09-07 08:09:13 +08:00
124 lines
3.7 KiB
C++
124 lines
3.7 KiB
C++
/****************************************************************************
|
|
Copyright (c) 2010-2012 cocos2d-x.org
|
|
Copyright (c) 2013-2016 Chukong Technologies Inc.
|
|
Copyright (c) 2017-2022 Xiamen Yaji Software Co., Ltd.
|
|
|
|
http://www.cocos.com
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
of this software and associated engine source code (the "Software"), a limited,
|
|
worldwide, royalty-free, non-assignable, revocable and non-exclusive license
|
|
to use Cocos Creator solely to develop games on your target platforms. You shall
|
|
not use Cocos Creator software for developing other software or tools that's
|
|
used for developing games. You are not granted to publish, distribute,
|
|
sublicense, and/or sell copies of Cocos Creator.
|
|
|
|
The software or tools in this License Agreement are licensed, not sold.
|
|
Xiamen Yaji Software Co., Ltd. reserves all rights not expressly granted to you.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
THE SOFTWARE.
|
|
****************************************************************************/
|
|
|
|
#pragma once
|
|
|
|
#include <cstdlib>
|
|
#include <random>
|
|
|
|
#include "base/Macros.h"
|
|
|
|
namespace cc {
|
|
|
|
/**
|
|
* @class RandomHelper
|
|
* @brief A helper class for creating random number.
|
|
*/
|
|
class CC_DLL RandomHelper {
|
|
public:
|
|
template <typename T>
|
|
static inline T randomReal(T min, T max) {
|
|
std::uniform_real_distribution<T> dist(min, max);
|
|
auto & mt = RandomHelper::getEngine();
|
|
return dist(mt);
|
|
}
|
|
|
|
template <typename T>
|
|
static inline T randomInt(T min, T max) {
|
|
std::uniform_int_distribution<T> dist(min, max);
|
|
auto & mt = RandomHelper::getEngine();
|
|
return dist(mt);
|
|
}
|
|
|
|
private:
|
|
static inline std::mt19937 &getEngine() {
|
|
static std::random_device seedGen;
|
|
static std::mt19937 engine(seedGen());
|
|
return engine;
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Returns a random value between `min` and `max`.
|
|
*/
|
|
template <typename T>
|
|
inline T random(T min, T max) {
|
|
return RandomHelper::randomInt<T>(min, max);
|
|
}
|
|
|
|
template <>
|
|
inline float random(float min, float max) {
|
|
return RandomHelper::randomReal(min, max);
|
|
}
|
|
|
|
template <>
|
|
inline long double random(long double min, long double max) {
|
|
return RandomHelper::randomReal(min, max);
|
|
}
|
|
|
|
template <>
|
|
inline double random(double min, double max) {
|
|
return RandomHelper::randomReal(min, max);
|
|
}
|
|
|
|
/**
|
|
* Returns a random int between 0 and RAND_MAX.
|
|
*/
|
|
inline int random() {
|
|
return cc::random(0, static_cast<int>(RAND_MAX));
|
|
};
|
|
|
|
/**
|
|
* Returns a random float between -1 and 1.
|
|
* It can be seeded using std::srand(seed);
|
|
*/
|
|
inline float randMinus1_1() {
|
|
// IDEA: using the new c++11 random engine generator
|
|
// without a proper way to set a seed is not useful.
|
|
// Resorting to the old random method since it can
|
|
// be seeded using std::srand()
|
|
return ((std::rand() / (float)RAND_MAX) * 2) - 1;
|
|
|
|
// return cc::random(-1.f, 1.f);
|
|
};
|
|
|
|
/**
|
|
* Returns a random float between 0 and 1.
|
|
* It can be seeded using std::srand(seed);
|
|
*/
|
|
inline float rand0_1() {
|
|
// IDEA: using the new c++11 random engine generator
|
|
// without a proper way to set a seed is not useful.
|
|
// Resorting to the old random method since it can
|
|
// be seeded using std::srand()
|
|
return std::rand() / (float)RAND_MAX;
|
|
|
|
// return cc::random(0.f, 1.f);
|
|
};
|
|
|
|
} // namespace cc
|