Aha so that's how antialiasing in gif works..

erik

In case you ever wondered what happens with antialiasing when saving to .gif:

If you don't draw a solid background, the gif gets a 1-bit mask and that looks very pixely:

size(100, 100)
fill(0)
oval(10, 10, 80, 80)
saveImage("test_no_background.gif")

If you do draw a background, the shape is antialised as expected:

size(100, 100)
fill(1)
rect(0,0,width(),height())
fill(0)
oval(10, 10, 80, 80)
saveImage("test_white_background.gif")!