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comparison semiconginev2/old/noise.nim @ 1218:56781cc0fc7c compiletime-tests

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did: renamge main package
author sam <sam@basx.dev>
date Wed, 17 Jul 2024 21:01:37 +0700
parents semicongine/old/noise.nim@a3eb305bcac2
children
comparison
equal deleted inserted replaced
1217:f819a874058f 1218:56781cc0fc7c
1 import hashes
2 import math
3
4 import ./core/vector
5
6
7 proc randomGradient(pos: Vec2f, seed: int32 = 0): Vec2f =
8 let randomAngle: float32 = TAU * (float32(int(hash((pos.x, pos.y, seed)))) / float32(high(int)))
9 return NewVec2f(cos(randomAngle), sin(randomAngle))
10
11 proc interpolate(a: float32, b: float32, weight: float32): float32 =
12 # with Smootherstep
13 (b - a) * ((weight * (weight * 6.0 - 15.0) + 10.0) * weight * weight * weight) + a;
14
15 proc Perlin*(pos: Vec2f, seed: int32 = 0): float32 =
16 let
17 # grid coordinates around target point
18 topleft = NewVec2f(trunc(pos.x), trunc(pos.y))
19 topright = topleft + NewVec2f(1, 0)
20 bottomleft = topleft + NewVec2f(0, 1)
21 bottomright = topleft + NewVec2f(1, 1)
22 # products for weights
23 topleft_dot = topleft.randomGradient(seed).Dot((pos - topleft))
24 topright_dot = topright.randomGradient(seed).Dot((pos - topright))
25 bottomleft_dot = bottomleft.randomGradient(seed).Dot((pos - bottomleft))
26 bottomright_dot = bottomright.randomGradient(seed).Dot((pos - bottomright))
27 xinterpol = pos.x - topleft.x
28 yinterpol = pos.y - topleft.y
29
30 return interpolate(
31 interpolate(topleft_dot, bottomleft_dot, yinterpol),
32 interpolate(topright_dot, bottomright_dot, yinterpol),
33 xinterpol
34 )