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

pixels = W:1024 H:1024

x = from -2 to 2 W
y = from -2 to 2 H

px = 2*fract(x) - 1
py = 2*fract(y) - 1

a = smoothstep(0.05, 0.0, abs(length2(px+1,py)-0.85) -0.08)
b = smoothstep(0.05, 0.0, abs(length2(px-1,py)-0.85) -0.08) 
c = smoothstep(0.05, 0.0, abs(length2(px,py+1)-0.85) -0.08)
d = smoothstep(0.05, 0.0, abs(length2(px,py-1)-0.85) -0.08)

k = 1 - min4(a, b, c, d)

r = k
g = k
b = k
