The blue polygon is the Minkowski difference between the red and green polygons. Note that it intersects with 0,0 when the green and red polygons intersect, even if they're concave.. A whole lot of useful things can be done with the Minkowski difference of two shapes, particularly in the context of physics engines... Also the visualization of the Minkowski difference could be better but I don't care- No, Sanic won't get this. I think.
