/*
 * rng.h
 *
 *  Created on: Mar 4, 2010
 *      Author: muecklgr_local
 */

/*
   Parts of this code were taken from the original Mersenne Twister
   code:

   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)
*/
#ifndef GLTB_RNG_H_
#define GLTB_RNG_H_

#include "GLTB/referencedobject.h"

/* Period parameters */
#define RANDOM_N 624
#define RANDOM_M 397
#define MATRIX_A 0x9908b0dfUL   /* constant vector a */
#define RANDOM_UPPER_MASK 0x80000000UL /* most significant w-r bits */
#define RANDOM_LOWER_MASK 0x7fffffffUL /* least significant r bits */

namespace gltb {
	class Random : public ReferencedObject {
	public:
		Random() { mti=RANDOM_N+1; }; /* mti==N+1 means mt[N] is not initialized */

		/* initializes mt[N] with a seed */
		void init(unsigned long s);
		/* initialize by an array with array-length */
		/* init_key is the array for initializing keys */
		/* key_length is its length */
		/* slight change for C++, 2004/2/26 */
		void init(unsigned long init_key[], int key_length);

		/* generates a random number on [0,0xffffffff]-interval */
		unsigned long genrandInt32(void);
		/* generates a random number on [0,0x7fffffff]-interval */
		long genrandInt31(void)
		{
			return (long)(genrandInt32()>>1);
		};

		/** generates a random number on [0,1]-real-interval */
		double genrandReal1(void)
		{
			return genrandInt32()*(1.0/4294967295.0);
			/* divided by 2^32-1 */
		};
		/** generates a random number on [0,1)-real-interval */
		double genrandReal2(void)
		{
			return genrandInt32()*(1.0/4294967296.0);
			/* divided by 2^32 */
		};
		/** generates a random number on (0,1)-real-interval */
		double genrandReal3(void)
		{
			return (((double)genrandInt32()) + 0.5)*(1.0/4294967296.0);
			/* divided by 2^32 */
		};
		/** generates a random number on [0,1) with 53-bit resolution*/
		double genrandRes53(void)
		{
			unsigned long a=genrandInt32()>>5, b=genrandInt32()>>6;
			return(a*67108864.0+b)*(1.0/9007199254740992.0);
		};
		/** These real versions are due to Isaku Wada, 2002/01/09 added */

	private:
		unsigned long mt[RANDOM_N]; /* the array for the state vector  */
		int mti; /* mti==N+1 means mt[N] is not initialized */

	};
}

#endif /* GLTB_RNG_H_ */