diff options
Diffstat (limited to 'source/blender/blenlib')
| -rw-r--r-- | source/blender/blenlib/BLI_rand.h | 2 | ||||
| -rw-r--r-- | source/blender/blenlib/intern/rand.c | 21 |
2 files changed, 23 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_rand.h b/source/blender/blenlib/BLI_rand.h index 378beff3aa0..20d5f8d8abf 100644 --- a/source/blender/blenlib/BLI_rand.h +++ b/source/blender/blenlib/BLI_rand.h @@ -49,6 +49,7 @@ void BLI_rng_srandom(struct RNG *rng, unsigned int seed); int BLI_rng_get_int(struct RNG *rng); double BLI_rng_get_double(struct RNG *rng); float BLI_rng_get_float(struct RNG *rng); +void BLI_rng_get_float_unit_v3(struct RNG *rng, float v[3]); void BLI_rng_shuffle_array(struct RNG *rng, void *data, int elemSize, int numElems); /** Note that skipping is as slow as generating n numbers! */ @@ -62,6 +63,7 @@ int BLI_rand(void); /** Return a pseudo-random number N where 0.0f<=N<1.0f */ float BLI_frand(void); +void BLI_frand_unit_v3(float v[3]); /** Return a pseudo-random (hash) float from an integer value */ float BLI_hash_frand(unsigned int seed); diff --git a/source/blender/blenlib/intern/rand.c b/source/blender/blenlib/intern/rand.c index c5b58e5a61b..f6f7c6e2486 100644 --- a/source/blender/blenlib/intern/rand.c +++ b/source/blender/blenlib/intern/rand.c @@ -32,6 +32,7 @@ #include <stdlib.h> #include <string.h> +#include <math.h> #include "MEM_guardedalloc.h" @@ -117,6 +118,21 @@ float BLI_rng_get_float(RNG *rng) return (float) BLI_rng_get_int(rng) / 0x80000000; } +void BLI_rng_get_float_unit_v3(RNG *rng, float v[3]) +{ + float r; + v[2] = (2.0f * BLI_rng_get_float(rng)) - 1.0f; + if ((r = 1.0f - (v[2] * v[2])) > 0.0f) { + float a = (float)(M_PI * 2.0) * BLI_rng_get_float(rng); + r = sqrtf(r); + v[0] = r * cosf(a); + v[1] = r * sinf(a); + } + else { + v[2] = 1.0f; + } +} + void BLI_rng_shuffle_array(RNG *rng, void *data, int elemSize, int numElems) { int i = numElems; @@ -173,6 +189,11 @@ float BLI_frand(void) return BLI_rng_get_float(&theBLI_rng); } +void BLI_frand_unit_v3(float v[3]) +{ + return BLI_rng_get_float_unit_v3(&theBLI_rng, v); +} + float BLI_hash_frand(unsigned int seed) { RNG rng; |