diff options
Diffstat (limited to 'src/proone_rnd.c')
-rw-r--r-- | src/proone_rnd.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/src/proone_rnd.c b/src/proone_rnd.c new file mode 100644 index 0000000..e4440e0 --- /dev/null +++ b/src/proone_rnd.c @@ -0,0 +1,94 @@ +#include "proone_rnd.h" + +#include <stdlib.h> + +#define N ((size_t)624) + + +struct proone_rnd_engine { + size_t mti; + uint32_t mt[N]; +}; + + +void proone_init_alloc_rnd_engine_result (proone_rnd_engnie_alloc_result_t *r) { + r->engine = NULL; + r->result = PROONE_RND_ENGINE_ALLOC_OK; +} + +proone_rnd_engnie_alloc_result_t proone_alloc_rnd_engine (const uint32_t *s) { + proone_rnd_engnie_alloc_result_t ret; + uint32_t seed; + + proone_init_alloc_rnd_engine_result(&ret); + + if (s == NULL) { + seed = 4357; + } + else { + if (*s == 0) { + ret.result = PROONE_RND_ENGINE_ALLOC_INVALID_SEED; + return ret; + } + seed = *s; + } + + ret.engine = (proone_rnd_engine_t*)malloc(sizeof(proone_rnd_engine_t)); + if (ret.engine == NULL) { + ret.result = PROONE_RND_ENGINE_ALLOC_MEM_ERR; + return ret; + } + + ret.engine->mt[0] = seed; + for (ret.engine->mti = 1; ret.engine->mti < N; ret.engine->mti += 1) { + ret.engine->mt[ret.engine->mti] = 69069 * ret.engine->mt[ret.engine->mti - 1]; + } + + return ret; +} + +void proone_free_rnd_engine (proone_rnd_engine_t *engine) { + free(engine); +} + +uint32_t proone_rnd_gen_int (proone_rnd_engine_t *engine) { + static const size_t M = 397; + static const uint32_t + MATRIX_A = 0x9908b0df, + UPPER_MASK = 0x80000000, + LOWER_MASK = 0x7fffffff, + TEMPERING_MASK_B = 0x9d2c5680, + TEMPERING_MASK_C = 0xefc60000; + uint32_t y; + static const uint32_t mag01[2] = {0, MATRIX_A}; + + if (engine->mti >= N) { + size_t kk; + + for (kk = 0; kk < N - M; kk += 1) { + y = (engine->mt[kk] & UPPER_MASK) | (engine->mt[kk + 1] & LOWER_MASK); + engine->mt[kk] = engine->mt[kk + M] ^ (y >> 1) ^ mag01[y & 1]; + } + for (; kk < N - 1; kk += 1) { + y = (engine->mt[kk] & UPPER_MASK) | (engine->mt[kk + 1] & LOWER_MASK); + engine->mt[kk] = engine->mt[kk + (M - N)] ^ (y >> 1) ^ mag01[y & 1]; + } + y = (engine->mt[N - 1] & UPPER_MASK) | (engine->mt[0] & LOWER_MASK); + engine->mt[N - 1] = engine->mt[M - 1] ^ (y >> 1) ^ mag01[y & 1]; + + engine->mti = 0; + } + + y = engine->mt[engine->mti]; + engine->mti += 1; + y ^= y >> 11; + y ^= (y << 7) & TEMPERING_MASK_B; + y ^= (y << 15) & TEMPERING_MASK_C; + y ^= y >> 18; + + return y; +} + +double proone_rnd_gen_double (proone_rnd_engine_t *engine) { + return (double)proone_rnd_gen_int(engine) * 2.3283064370807974e-10; +} |