mmc_rand_xorshift128p.h

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#ifndef _MCEXTREME_SFMT_RAND_H
#define _MCEXTREME_SFMT_RAND_H

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#ifndef inlinefun
    #define inlinefun static inline
#endif

typedef unsigned long long RandType;
typedef unsigned int uint;

#if defined(_WIN32) || defined(__APPLE__)
    typedef unsigned long long ulong;
#endif

#define MCX_RNG_NAME       "xorshift128+ RNG"
#define RAND_BUF_LEN       2        //register arrays
#define RAND_SEED_WORD_LEN      4        //48 bit packed with 64bit length

inlinefun void rng_init(RandType t[RAND_BUF_LEN], RandType tnew[RAND_BUF_LEN], uint* n_seed, int idx);

inlinefun void rand_need_more(RandType t[RAND_BUF_LEN], RandType tbuf[RAND_BUF_LEN]);
// generate [0,1] random number for the next scattering length
inlinefun float rand_next_scatlen(RandType t[RAND_BUF_LEN]);
// generate [0,1] random number for the next arimuthal angle
inlinefun float rand_next_aangle(RandType t[RAND_BUF_LEN]);
// generate random number for the next zenith angle
inlinefun float rand_next_zangle(RandType t[RAND_BUF_LEN]);
inlinefun float rand_next_reflect(RandType t[RAND_BUF_LEN]);
inlinefun float rand_do_roulette(RandType t[RAND_BUF_LEN]);

#ifdef MMC_USE_SSE_MATH
    inlinefun void rand_next_aangle_sincos(RandType t[RAND_BUF_LEN], float* si, float* co);
    inlinefun float rand_next_scatlen_ps(RandType t[RAND_BUF_LEN]);
#endif

#endif