Mercurial > games > semicongine
comparison semiconginev2/contrib/algorithms/noise.nim @ 1226:c8e3037aca66 compiletime-tests
add: contrib stuff
| author | sam <sam@basx.dev> |
|---|---|
| date | Wed, 17 Jul 2024 23:41:51 +0700 |
| parents | |
| children |
comparison
equal
deleted
inserted
replaced
| 1225:27cd1c21290e | 1226:c8e3037aca66 |
|---|---|
| 1 proc randomGradient(pos: Vec2f, seed: int32 = 0): Vec2f = | |
| 2 let randomAngle: float32 = TAU * (float32(int(hash((pos.x, pos.y, seed)))) / float32(high(int))) | |
| 3 return NewVec2f(cos(randomAngle), sin(randomAngle)) | |
| 4 | |
| 5 proc interpolate(a: float32, b: float32, weight: float32): float32 = | |
| 6 # with Smootherstep | |
| 7 (b - a) * ((weight * (weight * 6.0 - 15.0) + 10.0) * weight * weight * weight) + a; | |
| 8 | |
| 9 proc Perlin*(pos: Vec2f, seed: int32 = 0): float32 = | |
| 10 let | |
| 11 # grid coordinates around target point | |
| 12 topleft = NewVec2f(trunc(pos.x), trunc(pos.y)) | |
| 13 topright = topleft + NewVec2f(1, 0) | |
| 14 bottomleft = topleft + NewVec2f(0, 1) | |
| 15 bottomright = topleft + NewVec2f(1, 1) | |
| 16 # products for weights | |
| 17 topleft_dot = topleft.randomGradient(seed).Dot((pos - topleft)) | |
| 18 topright_dot = topright.randomGradient(seed).Dot((pos - topright)) | |
| 19 bottomleft_dot = bottomleft.randomGradient(seed).Dot((pos - bottomleft)) | |
| 20 bottomright_dot = bottomright.randomGradient(seed).Dot((pos - bottomright)) | |
| 21 xinterpol = pos.x - topleft.x | |
| 22 yinterpol = pos.y - topleft.y | |
| 23 | |
| 24 return interpolate( | |
| 25 interpolate(topleft_dot, bottomleft_dot, yinterpol), | |
| 26 interpolate(topright_dot, bottomright_dot, yinterpol), | |
| 27 xinterpol | |
| 28 ) |