SupSuper, I was thinking about real, 3d projected circle drawing (I already have pixe-by-pixel floating point line drawing algorithm, so this is not an issue). And for the moment I have no IDEA how to do it:). There seems to be alot of trigonometry stuff like arccos if I try to do it that way. Though there is another way - by simple ellipse drawing, without actual projecting, just simulating circles of the sphere (but need of tweaking to hide parts of circles).