A cool experiment. Select an operator (% is modulo), then drag the points around. This gets the distance from a pixel to both the circles, then puts the selected operator between them, (eg. d1 * d2). If the result is below a certain threshold, the pixel turns black, otherwise, it turns white.
My mind has been blown. This just got featured. Also please do not advertise. Or spam. Also check out the remixes! There are some pretty cool ones!