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// Required ?!?! - but seems to not work if not set
#define x64
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ObscureWare.Randomization;
/*
A C-program for MT19937, with initialization improved 2002/1/26.
Coded by Takuji Nishimura and Makoto Matsumoto.
Before using, initialize the state by using init_genrand(seed)
or init_by_array(init_key, key_length).
Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The names of its contributors may not be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Any feedback is very welcome.
http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
C# Version by Sebastian Gruchacz
August 2008, Sharp Devs Development
*/
namespace SharpDevs.Randomization
{
public class MersenneTwister : IRandomizer
{
const int N = 624;
const ulong M = 397;
const ulong MATRIX_A = 0x9908b0dfUL; /* constant vector a */
const ulong UPPER_MASK = 0x80000000UL; /* most significant w-r bits */
const ulong LOWER_MASK = 0x7fffffffUL; /* least significant r bits */
static ulong[] mt = new ulong[N]; /* the array for the state vector */
static int mti = N + 1; /* mti==N+1 means mt[N] is not initialized */
/// <summary>
/// initializes mt[N] with a seed
/// </summary>
/// <param name="seed"></param>
public MersenneTwister(int seed)
{
this.init_genrand((ulong)seed);
}
private void init_genrand(ulong seed)
{
mt[0] = seed & 0xffffffffUL;
for (mti = 1; mti < N; mti++)
{
mt[mti] = (1812433253UL * (mt[mti - 1] ^ (mt[mti - 1] >> 30)) + (ulong)mti);
/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
/* In the previous versions, MSBs of the seed affect */
/* only MSBs of the array mt[]. */
/* 2002/01/09 modified by Makoto Matsumoto */
#if x64
mt[mti] &= 0xffffffffUL; /* for >32 bit machines */
#endif
}
}
/* initialize by an array */
/* init_key is the array for initializing keys */
/* slight change for C++, 2004/2/26 */
public void InitByArray(ulong[] init_key)
{
int i, j, k;
this.init_genrand(19650218UL);
i = 1; j = 0;
k = (N > init_key.Length ? N : init_key.Length);
for (; k > 0; k--)
{
mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1664525UL)) + init_key[j] + (ulong)j; /* non linear */
#if x64
mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
#endif
i++; j++;
if (i >= N) { mt[0] = mt[N - 1]; i = 1; }
if (j >= init_key.Length) j = 0;
}
for (k = N - 1; k > 0; k--)
{
mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1566083941UL)) - (ulong)i; /* non linear */
#if x64
mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
#endif
i++;
if (i >= N) { mt[0] = mt[N - 1]; i = 1; }
}
mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
}
static ulong[] mag01 = new ulong[] { 0x0UL, MATRIX_A };
/* generates a random number on [0,0xffffffff]-interval */
private ulong genrand_int32()
{
ulong y;
/* mag01[x] = x * MATRIX_A for x=0,1 */
if (mti >= N)
{ /* generate N words at one time */
ulong kk;
if (mti == N + 1) /* if init_genrand() has not been called, */
this.init_genrand(5489UL); /* a default initial seed is used */
for (kk = 0; kk < N - M; kk++)
{
y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
mt[kk] = mt[kk + M] ^ (y >> 1) ^ mag01[y & 0x1UL];
}
for (; kk < N - 1; kk++)
{
y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
mt[kk] = mt[kk + M - N] ^ (y >> 1) ^ mag01[y & 0x1UL];
}
y = (mt[N - 1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
mt[N - 1] = mt[M - 1] ^ (y >> 1) ^ mag01[y & 0x1UL];
mti = 0;
}
y = mt[mti++];
/* Tempering */
y ^= (y >> 11);
y ^= (y << 7) & 0x9d2c5680UL;
y ^= (y << 15) & 0xefc60000UL;
y ^= (y >> 18);
return y;
}
#region IRandomizer Members
public ulong GetNextULong()
{
return this.genrand_int32();
}
public int GetNext()
{
return (int) this.genrand_int32();
}
public int GetNext(int max)
{
return (int)(this.GetNextDouble() * (double)max);
}
public int GetNext(int min, int max)
{
return (int)(this.GetNextDouble() * ((double)max - (double)min) + (double)min);
//return (int)((long)(GetNextDouble() * ((double)max - (double)min) + (double)min) & (long)int.MaxValue);
}
public double GetNextDouble()
{
// 53 bit
ulong a = this.genrand_int32() >> 5;
ulong b = this.genrand_int32() >> 6;
return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
}
#endregion
}
}