Function noise

shaders/src/clouds.rs:28–48

(p: Vec2)

}

fn noise(p: Vec2) -> f32 {
    const K1: f32 = 0.366025404; // (sqrt(3)-1)/2;
    const K2: f32 = 0.211324865; // (3-sqrt(3))/6;
    let i: Vec2 = (p + Vec2::splat((p.x + p.y) * K1)).floor();
    let a: Vec2 = p - i + Vec2::splat((i.x + i.y) * K2);
    let o: Vec2 = if a.x > a.y {
        vec2(1.0, 0.0)
    } else {
        vec2(0.0, 1.0)
    }; //vec2 of = 0.5 + 0.5*vec2(sign(a.x-a.y), sign(a.y-a.x));
    let b: Vec2 = a - o + Vec2::splat(K2);
    let c: Vec2 = a - Vec2::splat(1.0 - 2.0 * K2);
    let h: Vec3 = (Vec3::splat(0.5) - vec3(a.dot(a), b.dot(b), c.dot(c))).max(Vec3::ZERO);
    let n: Vec3 = (h * h * h * h)
        * vec3(
            a.dot(hash(i + Vec2::ZERO)),
            b.dot(hash(i + o)),
            c.dot(hash(i + Vec2::splat(1.0))),
        );
    n.dot(Vec3::splat(70.0))
}

fn fbm(mut n: Vec2) -> f32 {
    let mut total: f32 = 0.0;