axmol/cocos/base/ccRandom.h

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Copyright (c) 2010      cocos2d-x.org
Copyright (c) 2013-2014 Chukong Technologies Inc.

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#ifndef __ccRandom_H_
#define __ccRandom_H_

#include "base/CCPlatformMacros.h"
#include <random>


NS_CC_BEGIN

class CC_DLL RandomHelper {
public:
    template<typename T>
    static inline T random_real(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 random_int(T min, T max) {
        std::uniform_int_distribution<> dist(min, max);
        auto &mt = RandomHelper::getEngine();
        return dist(mt);
    }
private:
    static std::mt19937 &getEngine();
};

/**
* returns a random value between `min` and `max`
*/
template<typename T>
inline T random(T min, T max) {
    return RandomHelper::random_int(min, max);
}

template<>
inline float random(float min, float max) {
    return RandomHelper::random_real(min, max);
}

template<>
inline long double random(long double min, long double max) {
    return RandomHelper::random_real(min, max);
}

template<>
inline double random(double min, double max) {
    return RandomHelper::random_real(min, max);
}

/**
* returns a random int between 0 and RAND_MAX
*/
inline int random() {
    return cocos2d::random(0, RAND_MAX);
};

/**
* returns a random float between -1 and 1
*/
inline float rand_minus1_1() {
    return cocos2d::random(-1.f, 1.f);
};

/**
* returns a random float between 0 and 1
*/
inline float rand_0_1() {
    return cocos2d::random(0.f, 1.f);
};

NS_CC_END
#endif //__ccRandom_H_