random.h

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#ifndef BJ_RANDOM_H
#define BJ_RANDOM_H
 
#include <banjo/api.h>
#include <banjo/math.h>

#define BJ_RAND_MAX 0x7FFF

void bj_srand(unsigned int seed);

int bj_rand(void);

struct bj_pcg32 {
    uint64_t state; 
    uint64_t inc;   
};

struct bj_pcg32;

void bj_seed_pcg32(
    struct bj_pcg32* generator,
    uint64_t  seed,
    uint64_t  seq
);

uint32_t bj_next_pcg32(
    struct bj_pcg32* generator
);

void bj_discard_pcg32(
    struct bj_pcg32* generator,
    uint64_t  z
);

uint32_t bj_min_pcg32(void);

uint32_t bj_max_pcg32(void);

static BJ_INLINE uint32_t bj_pcg32_generator(void* state) {
    return bj_next_pcg32((struct bj_pcg32*)state);
}

typedef uint32_t (*bj_random_u32_fn)(void* state);

BANJO_EXPORT int32_t bj_uniform_int32_distribution(
    bj_random_u32_fn next,
    void*              state,
    int32_t            low,
    int32_t            high
);

BANJO_EXPORT float bj_uniform_float_distribution(
    bj_random_u32_fn next,
    void*              state,
    float              low,
    float              high
);

BANJO_EXPORT double bj_uniform_double_distribution(
    bj_random_u32_fn next,
    void*              state,
    double             low,
    double             high
);

BANJO_EXPORT long double bj_uniform_long_double_distribution(
    bj_random_u32_fn next,
    void*              state,
    long double        low,
    long double        high
);

#if defined(BJ_API_LONG_DOUBLE)
    #define bj_uniform_real_distribution  bj_uniform_long_double_distribution
#elif defined(BJ_API_FLOAT64)
    #define bj_uniform_real_distribution  bj_uniform_double_distribution
#else
    #define bj_uniform_real_distribution  bj_uniform_float_distribution
#endif

BANJO_EXPORT int bj_bernoulli_distribution(
    bj_random_u32_fn next,
    void*              state,
    bj_real            probability
);

BANJO_EXPORT float bj_normal_float_distribution(
    bj_random_u32_fn next,
    void*              state,
    float              mean,
    float              standard_deviation
);

BANJO_EXPORT double bj_normal_double_distribution(
    bj_random_u32_fn next,
    void*              state,
    double             mean,
    double             standard_deviation
);

BANJO_EXPORT long double bj_normal_long_double_distribution(
    bj_random_u32_fn next,
    void*              state,
    long double        mean,
    long double        standard_deviation
);

#if defined(BJ_API_LONG_DOUBLE)
    #define bj_normal_real_distribution  bj_normal_long_double_distribution
#elif defined(BJ_API_FLOAT64)
    #define bj_normal_real_distribution  bj_normal_double_distribution
#else
    #define bj_normal_real_distribution  bj_normal_float_distribution
#endif
 
#endif /* BJ_RANDOM_H */

BANJO_EXPORT float bj_normal_float_minmax_distribution(
    bj_random_u32_fn next,
    void*              state,
    float              min,
    float              max
);

BANJO_EXPORT double bj_normal_double_minmax_distribution(
    bj_random_u32_fn next,
    void*              state,
    double             min,
    double             max
);

BANJO_EXPORT long double bj_normal_long_double_minmax_distribution(
    bj_random_u32_fn next,
    void*              state,
    long double        min,
    long double        max
);

#if defined(BJ_API_LONG_DOUBLE)
    #define bj_normal_real_minmax_distribution  bj_normal_long_double_minmax_distribution
#elif defined(BJ_API_FLOAT64)
    #define bj_normal_real_minmax_distribution  bj_normal_double_minmax_distribution
#else
    #define bj_normal_real_minmax_distribution  bj_normal_float_minmax_distribution
#endif