#https://www.shadertoy.com/view/Md2cDK

pixels = W:1024 H:1024

x = from -1.0 to 1.0 W
y = from -1.0 to 1.0 H

g = 0.618
s = 5

b = length2(x, y)
a = atan2(y, x)

k = log(b)/g + a

r = sin(k*s)
g = r
b = r
