pixels = W:1024 H:1024

x = from 0 to 256 W
y = from 0 to 256 H

a = 0
b = 256
c =128

w = smoothstep(a, a + c, y) * (1.0 - smoothstep(b - c, b, y))

k = (tex_hash2(x, y) > 0.8) * (w > xor_hash2(x, y))

r = k
g = r
b = r
