#https://www.shadertoy.com/view/XtlXzN

pixels = W:1024 H:1024

x = from -2.0 to 2.0 W
y = from -2.0 to 2.0 H

t = 1.0

a = atan2(y, x)
b = 2*PI/4
k = ceil(a/b-0.5)*b-a
r = length2(x, y)

gx = a/PI*2*pow(r, 5)
gy = cos(k)/abs(tan(k))*pow(r, 5)

r = tex_noise2(gx, gy - t*0.5)*sqrt(gy)
g = r
b = r
