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

pixels = W:1024 H:1024

x = from (-4*PI) to (4*PI) W
y = from (-4*PI) to (4*PI) H

ax = x
ay = y

[loop start:18
d = ax*ax + ay*ay
ax = abs(ax)/d - 0.8
ay = abs(ay)/d - 0.8
loop end]

k = sqrt(ax*ax + ay*ay)

r = pow(k, 1.5)*0.04
g = r
b = r