Fast, precise flattening of cubic Bezier segment offset curves

A fast algorithm for generating a polyline approximation (flattening) for the offset curves of a cubic Bezier curve segment is described. It is shown to be more efficient than the standard recursive subdivision method by generating only 70% as many segments, but, just as importantly, 94% of all segments fall within 20% of the flatness criterion. The code runs as fast as recursive subdivision.