A Bézier curve has the
GOT_BEZIER type and can be either
GOST_BEZIER_CUBIC. Both of them have an anchor for the start point, one
for the end point. The quadratic Bézier curve has another anchor for the control
point, the cubic Bézier curve has two control points. For each point there is
a weight property defining the rational weight of the point.
Both the quadratic and cubic Bézier curves have a curve hanger, a start point hanger and an end point hanger.