GF. best viewed at zoom = 100% See an animated demo of the rotation-via-shearing algorithm at http://g6auc.me.uk/ellipses/index.html Full ellipse library at http://scratch.mit.edu/projects/50039326/
This is the same code as http://scratch.mit.edu/projects/49800724/ except that it applies a shear to the Y coordinate that is proportional to the X coordinate. This results in an ellipse that has axes that are no longer axis-aligned. It's possible (see http://g6auc.me.uk/shear.htm) to define an ellipse-drawing procedure that takes the traditional 2 loci plus distance (or equivalently, two axes plus rotation) and maps that definition to the center and radius of a circle plus the needed shear parameters that distort it to match the desired ellipse. A more efficient implementation would combine Bresenham's line algorithm to do the shear with Bresenham's circle algorithm.
