GF. best viewed at zoom = 100% I don't think this expression of the algorithm will be transparency-friendly. It could be rewritten that way. The problem is that we're taking advantage of X/Y symmetry and drawing 1/8 of a circle at a time.
This is a minor hack to http://scratch.mit.edu/projects/49800724/ to make Bresenham's Circle algorithm draw filled circles instead of just outlines. It's not that much more expensive in Scratch. (Mind you, pen down/pen up with a large pen size is generally more efficient!)
