EHS/include/ehs/PRNG.h

#pragma once

#include "EHS.h"

namespace ehs
{
    template<typename T>
    class PRNG
    {
    private:
        T seed;
        T last;

    public:
        PRNG()
            : seed(0), last(0)
        {
        }

        PRNG(const T seed)
            : seed(seed), last(seed)
        {
        }

        PRNG(const PRNG& prng)
            : seed(prng.seed), last(prng.last)
        {
        }

        PRNG& operator=(const PRNG& prng)
        {
            if (this == &prng)
                return *this;

            seed = prng.seed;
            last = prng.last;

            return *this;
        }

        T Generate(const T min, const T max)
        {
            return Generate() % (max - min) + min;
        }

        T Generate()
        {
            return ((last = last * (T)214013 + (T)2531011) >> 16) & (T)0x7fff;
        }
    };

	typedef PRNG<SInt_64> PRNG_s64;
    typedef PRNG<UInt_64> PRNG_u64;
	typedef PRNG<SInt_32> PRNG_s32;
    typedef PRNG<UInt_32> PRNG_u32;
	typedef PRNG<SInt_16> PRNG_s16;
	typedef PRNG<UInt_16> PRNG_u16;
	typedef PRNG<SInt_8> PRNG_s8;
	typedef PRNG<UInt_8> PRNG_u8;
}