#include <stdio.h>
#include <stdint.h>
#include <string.h>

/* Period parameters */  
#define N 624
#define M 397
#define MATRIX_A 0x9908b0df   /* constant vector a */
#define UPPER_MASK 0x80000000 /* most significant w-r bits */
#define LOWER_MASK 0x7fffffff /* least significant r bits */

/* Tempering parameters */   
#define TEMPERING_MASK_B 0x9d2c5680
#define TEMPERING_MASK_C 0xefc60000
#define TEMPERING_SHIFT_U(y)  (y >> 11)
#define TEMPERING_SHIFT_S(y)  (y << 7)
#define TEMPERING_SHIFT_T(y)  (y << 15)
#define TEMPERING_SHIFT_L(y)  (y >> 18)

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

/* initializing the array with a NONZERO seed */
void sgenrand (unsigned long seed)
{
	/* setting initial seeds to mt[N] using         */
	/* the generator Line 25 of Table 1 in          */
	/* [KNUTH 1981, The Art of Computer Programming */
	/*    Vol. 2 (2nd Ed.), pp102]                  */
	mt[0]= seed & 0xffffffff;
	for (mti=1; mti<N; mti++)
		mt[mti] = (69069 * mt[mti-1]) & 0xffffffff;
}

unsigned long genrand()
{
	unsigned long y;
	static unsigned long mag01[2]={0x0, MATRIX_A};
	/* mag01[x] = x * MATRIX_A  for x=0,1 */

	if (mti >= N) { /* generate N words at one time */
		int kk;

		if (mti == N+1)   /* if sgenrand() has not been called, */
			sgenrand(4357); /* 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 & 0x1];
		}
		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 & 0x1];
		}
		y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
		mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1];

		mti = 0;
	}

	y = mt[mti++];
	y ^= TEMPERING_SHIFT_U(y);
	y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B;
	y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C;
	y ^= TEMPERING_SHIFT_L(y);

	return y; 
}

int main()
{
        sgenrand(1);

        for (int i=0; i<0xffff; i++)
        {
                uint32_t t=genrand();
                float a;
                memcpy (&a, &t, 4);
                //printf ("0x%x %f %e\n", t, a, a);
                printf ("%u, %e\n", t, a);
        };

        return 0;
}