diff options
Diffstat (limited to 'src/noise.cpp')
| -rw-r--r-- | src/noise.cpp | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/src/noise.cpp b/src/noise.cpp index 2948fb765..2ddc3926f 100644 --- a/src/noise.cpp +++ b/src/noise.cpp @@ -99,17 +99,17 @@ u32 PcgRandom::range(u32 bound) Using rand() % 3, the number 0 would be twice as likely to appear. With a very large RNG range, the effect becomes less prevalent but still present. This can be solved by modifying the range of the RNG - to become a multiple of bound by dropping values above the a threshhold. - In our example, threshhold == 4 - 3 = 1 % 3 == 1, so reject 0, thus + to become a multiple of bound by dropping values above the a threshold. + In our example, threshold == 4 - 3 = 1 % 3 == 1, so reject 0, thus making the range 3 with no bias. This loop looks dangerous, but will always terminate due to the RNG's property of uniformity. */ - u32 threshhold = -bound % bound; + u32 threshold = -bound % bound; u32 r; - while ((r = next()) < threshhold) + while ((r = next()) < threshold) ; return r % bound; @@ -158,21 +158,21 @@ s32 PcgRandom::randNormalDist(s32 min, s32 max, int num_trials) float noise2d(int x, int y, int seed) { - int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + unsigned int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + NOISE_MAGIC_SEED * seed) & 0x7fffffff; n = (n >> 13) ^ n; n = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff; - return 1.f - (float)n / 0x40000000; + return 1.f - (float)(int)n / 0x40000000; } float noise3d(int x, int y, int z, int seed) { - int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + NOISE_MAGIC_Z * z + unsigned int n = (NOISE_MAGIC_X * x + NOISE_MAGIC_Y * y + NOISE_MAGIC_Z * z + NOISE_MAGIC_SEED * seed) & 0x7fffffff; n = (n >> 13) ^ n; n = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff; - return 1.f - (float)n / 0x40000000; + return 1.f - (float)(int)n / 0x40000000; } |