Thanks Simetrical, looks like a good summary of the thread. I'm afraid I didn't have time to do one myself.

One question though - where do you get the 15.88 figure? The reason I ask is that I don't think it's actually possible to be 15.88 tiles away. 15.81 would be the closest, e.g. (15,5) or (13,9). The next possible distance after that is 16, i.e. (16,0) or (0,16). Just curious.