Random64d.cs

64 Bit Version of Random

using System;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
[Serializable]
public class Random64d : RandomNumberGenerator
{
    private const                    double                   DBi  = 1.0 / 9223372036854775807;
    private const                    double                   DBui = 1.0 / ulong.MaxValue;
    private readonly                 Random                   _r1;
    private readonly                 Random                   _r2;
    [NonSerialized] private readonly RNGCryptoServiceProvider _rng = new RNGCryptoServiceProvider();
    private                          RNumber                  _rNumber;
    public Random64d() : this(((long) (uint) Environment.TickCount << 32) | (uint) Environment.TickCount)
    {
    }
    public Random64d(long Seed)
    {
        var Seed0 = (int) (((Seed ^ 0x86B28CAB) << 16) & 0x7fffffff);
        var Seed1 = (int) (Seed                        & 0x7fffffff);
        _r1 = new Random(Seed0);
        _r2 = new Random(Seed1);
    }
    public long InternalSample()
    {
        _rNumber.n1 = _r1.Next();
        _rNumber.n2 = _r2.Next();
        return _rNumber.total;
    }
    private double GetSampleForLargeRange()
    {
        var value = InternalSample();
        if (InternalSample() % 2 == 0)
            value = -value;
        return (value + 4611686018427387903.0) / 9223372036854775807.0;
    }
    private double Sample()
    {
        return InternalSample() * DBi;
    }
    public long Next()
    {
        return InternalSample();
    }
    public long Next(long minValue, long maxValue)
    {
        if (minValue > maxValue)
            throw new ArgumentException("maxValue must be greater than or equal to minValue");
        var num = (ulong) maxValue - (ulong) minValue;
        if (num <= long.MaxValue)
            return (long) (Sample() * num) + minValue;
        return (long) ((ulong) (GetSampleForLargeRange() * num) + (ulong) minValue);
    }
    public ulong Next(ulong minValue, ulong maxValue)
    {
        if (minValue > maxValue)
            throw new ArgumentException("maxValue must be greater than or equal to minValue");
        var num = maxValue - minValue;
        return (ulong) (InternalSample() * DBui * num) + minValue;
    }
    public long Next(long maxValue)
    {
        if (maxValue < 0)
            throw new ArgumentException("maxValue must be greater than zero.");
        return (long) (Sample() * maxValue);
    }
    public ulong Next(ulong maxValue)
    {
        return (ulong) (InternalSample() * DBui * maxValue);
    }
    public double NextDouble()
    {
        return Sample();
    }
    public byte[] GetNextByteArray(int size)
    {
        var ba = new byte[size];
        _rng.GetBytes(ba);
        return ba;
    }
    public byte[] GetNextByteArrayFn(int size)
    {
        var ba = new byte[size];
        for (var i = 0; i < size; ++i)
            ba[i] = (byte) Next(0, 256);
        return ba;
    }
    public char[] GetNextCharArray(int size)
    {
        var ca = new char[size];
        for (var i = 0; i < size; ++i)
            ca[i] = (char)Next(32, 128);
        return ca;
    }
    public string GetRandomString(int minLen, int maxLen)
    {
        if (minLen == maxLen)
            return new string(GetNextCharArray(minLen));
        return new string(GetNextCharArray((int) Next(minLen, maxLen)));
    }
    public override void GetBytes(byte[] data)
    {
        if (data == null)
            throw new ArgumentException("The buffer cannot be null.");
        _rng.GetBytes(data);
    }
    [StructLayout(LayoutKind.Explicit, Size = 8, Pack = 1)]
    [Serializable]
    public struct RNumber
    {
        [FieldOffset(0)] public long n1;
        [FieldOffset(4)] public long n2;
        [FieldOffset(0)] public long total;
    }
}