Mercurial > games > semicongine
changeset 1436:cf0bae787044
add: squirrel hash
| author | sam <sam@basx.dev> |
|---|---|
| date | Mon, 20 Jan 2025 23:12:30 +0700 |
| parents | 7de637b83272 |
| children | e54ef155de10 |
| files | semicongine/contrib/algorithms/noise.nim |
| diffstat | 1 files changed, 15 insertions(+), 0 deletions(-) [+] |
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--- a/semicongine/contrib/algorithms/noise.nim Sun Jan 19 23:58:44 2025 +0700 +++ b/semicongine/contrib/algorithms/noise.nim Mon Jan 20 23:12:30 2025 +0700 @@ -3,6 +3,21 @@ import ../../core +# nice hash function, from a GDC talk +proc squirrel3(position: uint32, seed: uint32 = 0'u32): uint32 = + const + NOISE1 = 0xB5297A4D'u32 + NOISE2 = 0x68E31DA4'u32 + NOISE3 = 0x1B56C4E9'u32 + result = position + result += seed + result *= NOISE1 + result = result xor (result shr 8'u32) + result += NOISE2 + result = result xor (result shl 8'u32) + result *= NOISE3 + result = result xor (result shr 8'u32) + proc randomGradient(pos: Vec2f, seed: uint64 = 0): Vec2f = let randomAngle: float32 = TAU * (float32(int(hash((pos.x, pos.y, seed)))) / float32(high(int)))