These are the coordinates produced by Michael's algorithm for radius = 10: ( 0, 10) ( 1, 10) ( 2, 10) ( 3, 10) ( 4, 9) ( 5, 9) ( 6, 8) ( 7, 7) ( 8, 6) ( 9, 4) (10, 0) Now, if you plot these points you'll notice that the the resulting curve is not continuous. There are gaps between (8, 6) & (9, 4) and (9, 4) & (10, 0). How did you handle that? Thanks for the article, it was an interesting read :) Mahmoud