> the more red pixels you have on the screen already, the less likely is that you hit a new yet-not-red pixel, so the final pixels take forever to turn red Thi

> the more red pixels you have on the screen already, the less likely is that you hit a new yet-not-red pixel, so the final pixels take forever to turn red This would be true when using the built-in random number generator, modding the result to a pixel on the screen. However, this is not how the "maximum-length" LFSR proposed in the original article works. It visits each pixel exactly once, and turns the screen completely red in a deterministic amount of time. (Just see the screenshot here: http://fabiensanglard.net/fizzlefade/die.gif http://fabiensanglard.net/fizzlefade/die.gif) This behavior is indicated from the stopping condition in the Wolf3D asm code alone -- the seed starts at 1. It terminates when the random number returns to 1, completing the cycle through the number space.