diff options
Diffstat (limited to 'src/libmowgli/base/random.c')
| -rw-r--r-- | src/libmowgli/base/random.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/src/libmowgli/base/random.c b/src/libmowgli/base/random.c index b316033..a183057 100644 --- a/src/libmowgli/base/random.c +++ b/src/libmowgli/base/random.c @@ -27,9 +27,9 @@ /* period parameters */ #define N 624 #define M 397 -#define MATRIX_A 0x9908b0dfUL /* constant vector a */ -#define UPPER_MASK 0x80000000UL /* most significant w-r bits */ -#define LOWER_MASK 0x7fffffffUL /* least significant r bits */ +#define MATRIX_A 0x9908b0dfUL /* constant vector a */ +#define UPPER_MASK 0x80000000UL /* most significant w-r bits */ +#define LOWER_MASK 0x7fffffffUL /* least significant r bits */ /* mowgli_random_t contains state data which is private */ struct mowgli_random_ @@ -42,20 +42,24 @@ struct mowgli_random_ static mowgli_object_class_t klass; /* initialization */ -void mowgli_random_bootstrap(void) +void +mowgli_random_bootstrap(void) { mowgli_object_class_init(&klass, "mowgli_random_t", NULL, FALSE); } /* construction and destruction. */ -mowgli_random_t *mowgli_random_create(void) +mowgli_random_t * +mowgli_random_create(void) { return mowgli_random_create_with_seed(time(NULL)); } -mowgli_random_t *mowgli_random_create_with_seed(unsigned int seed) +mowgli_random_t * +mowgli_random_create_with_seed(unsigned int seed) { mowgli_random_t *out = mowgli_alloc(sizeof(mowgli_random_t)); + mowgli_object_init(mowgli_object(out), NULL, &klass, NULL); mowgli_random_reseed(out, seed); @@ -64,11 +68,13 @@ mowgli_random_t *mowgli_random_create_with_seed(unsigned int seed) } /* reset seed */ -void mowgli_random_reseed(mowgli_random_t *self, unsigned int seed) +void +mowgli_random_reseed(mowgli_random_t *self, unsigned int seed) { return_if_fail(self != NULL); self->mt[0] = seed & 0xffffffffUL; + for (self->mti = 1; self->mti < N; self->mti++) { self->mt[self->mti] = (1812433253UL * (self->mt[self->mti - 1] ^ (self->mt[self->mti - 1] >> 30)) + self->mti); @@ -77,7 +83,8 @@ void mowgli_random_reseed(mowgli_random_t *self, unsigned int seed) } /* number retrieval */ -unsigned int mowgli_random_int(mowgli_random_t *self) +unsigned int +mowgli_random_int(mowgli_random_t *self) { unsigned int y; static unsigned int mag01[2] = { 0x0UL, MATRIX_A }; @@ -97,7 +104,7 @@ unsigned int mowgli_random_int(mowgli_random_t *self) for (; t < N - 1; t++) { y = (self->mt[t] & UPPER_MASK) | (self->mt[t + 1] & LOWER_MASK); - self->mt[t] = self->mt[t + (M - N)] ^ (y >> 1) ^ mag01[y & 0x1U]; + self->mt[t] = self->mt[t + (M - N)] ^ (y >> 1) ^ mag01[y & 0x1U]; } y = (self->mt[N - 1] & UPPER_MASK) | (self->mt[0] & LOWER_MASK); @@ -116,7 +123,8 @@ unsigned int mowgli_random_int(mowgli_random_t *self) return y; } -int mowgli_random_int_ranged(mowgli_random_t *self, int begin, int end) +int +mowgli_random_int_ranged(mowgli_random_t *self, int begin, int end) { unsigned int dist = end - begin; unsigned int max, ret; @@ -129,13 +137,16 @@ int mowgli_random_int_ranged(mowgli_random_t *self, int begin, int end) remain -= dist; max = 0xFFFFFFFFU - remain; - } else + } + else + { max = dist - 1; + } do - { ret = mowgli_random_int(self); - } while (ret > max); + + while (ret > max); ret %= dist; |