FLAG_KNOT

FLAG_KNOT_T_BREAK	Break knot tangents.
FLAG_KNOT_LOCK_X	Lock knot’s X movement.
FLAG_KNOT_LOCK_Y	Lock knot’s Y movement.
FLAG_KNOT_T_LOCK_A	Lock knot’s tangent angle.
FLAG_KNOT_T_LOCK_L	Lock knot’s tangent length.
FLAG_KNOT_T_KEEPVISUALANGLE	Keep visual angle between knot’s tangents.
ADD_KNOT_ADAPT_TANGENTS	Tangents of new knots are set in such a way that the resulting spline will match the curvature of the original spline.