MT Wrapper

// Mersenne Twister Engine wrapper
// Author(s):       iFarbod <[email protected]>
//
// Copyright (c) 2014-2016 San Andreas Online
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.

#pragma once
#include "types.hpp"
#include "MT.hpp"

#ifdef _WIN32
#include <Windows.h>
#else // TODO: move this to a utility function
#include <sys/time.h>

inline unsigned GetTickCount__mtrand()
{
    struct timeval tv;
    if (gettimeofday(&tv, NULL) != 0)
        return 0;

    return (tv.tv_sec * 1000) + (tv.tv_usec / 1000);
}

#endif // _WIN32

class MTRand
{
private:
    class _11213b
    {
    private:
        MT11213b rnd;
    public:
        _11213b()
        {
#ifdef _WIN32
            rnd.seed(GetTickCount());
#else
            rnd.seed(GetTickCount__subrand());
#endif // _WIN32
        }

        u32 Next()
        {
            return rnd();
        }

        u32 Next(u32 max)
        {
            return Next() % max;
        }

        // [min, max)
        u32 Next(u32 min, u32 max)
        {
            return Next((max - min)) + min;
        }

        // inclusive
        // [min, max]
        u32 Next_(u32 min, u32 max)
        {
            return Next((max - min) + 1) + min;
        }

        bool NextBool()
        {
            return Next(2) != 0;
        }
    } _MT11213b;

    class _19937
    {
    private:
        MT19937 rnd;
    public:
        _19937()
        {
#ifdef _WIN32
            rnd.seed(GetTickCount());
#else
            rnd.seed(GetTickCount__subrand());
#endif // _WIN32
        }

        u32 Next()
        {
            return rnd();
        }

        u32 Next(u32 max)
        {
            return Next() % max;
        }

        u32 Next(u32 min, u32 max)
        {
            return Next((max - min)) + min;
        }

        // inclusive
        // [min, max]
        u32 Next_(u32 min, u32 max)
        {
            return Next((max - min) + 1) + min;
        }

        bool NextBool()
        {
            return Next(2) != 0;
        }
    } _MT19937;

    class _19937_64
    {
    private:
        MT19937_64 rnd;
    public:
        _19937_64()
        {
#ifdef _WIN32
            rnd.seed(GetTickCount64());
#else
            rnd.seed(GetTickCount__subrand());
#endif // _WIN32
        }

        u64 Next()
        {
            return rnd();
        }

        u64 Next(u64 max)
        {
            return Next() % max;
        }

        u64 Next(u64 min, u64 max)
        {
            return Next((max - min)) + min;
        }

        // inclusive
        // [min, max]
        u64 Next_(u64 min, u64 max)
        {
            return Next((max - min) + 1) + min;
        }

        bool NextBool()
        {
            return Next(2) != 0;
        }
    } _MT19937_64;

    //
    // Instance getter functions
    //
public:
    inline decltype(_MT11213b)& GetMT11213b()
    {
        return _MT11213b;
    }

    inline decltype(_MT19937)& GetMT19937()
    {
        return _MT19937;
    }

    inline decltype(_MT19937_64)& GetMT19937_64()
    {
        return _MT19937_64;
    }

    // -----------------------------------------
    // --------------- Singleton ---------------
    // -----------------------------------------
public:
    static MTRand& GetInstance()
    {
        static MTRand instance;
        return instance;
    }
private:
    MTRand()
    {}

public:
    MTRand(MTRand const&) = delete;
    void operator=(MTRand const&) = delete;

};
static MTRand& mtrand = MTRand::GetInstance(); // for easy use