Add a section of a cubic Bézier curve described by the three given control
points to the current path.
Resource identifier of the postscript file
as returned by ps_new().
x-coordinate of first control point.
y-coordinate of first control point.
x-coordinate of second control point.
y-coordinate of second control point.
x-coordinate of third control point.
y-coordinate of third control point.
Returns TRUE on success or FALSE on failure.