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

pixels = W:1024 H:1024

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

t = 1.0

a = atan2(x, y) / PI * 5.0
m = length2(x, y) - t

u = abs(fract(a+m)-0.5)
v = abs(fract(a-m)-0.5)

r = u
g = v
b = 0.5 + 0.5*sin(m)
