PK_ERROR_code_t   PK_BCURVE_sweep
(
--- received arguments ---
PK_BCURVE_t       bcurve,      --- bcurve
PK_VECTOR_t       path,        --- translation vector

--- returned arguments ---
PK_BSURF_t *const bsurf        --- resulting bsurf
)


This function sweeps a bcurve into a bsurf.


Specific Errors:
    PK_ERROR_null_direction        zero length path vector given


The bcurve is moved along the path vector sweeping out a bsurf.



Returned surface bsurf:
. The given bcurve lies along the v = 0 parameter line of the surface.
. The surface has the same dimension as the curve.
. The u order of the surface is the order of the curve.
. The v order of the surface is 2.
. The surface normal is in the direction of the cross product of the bcurve
  tangent and the path vector.

In general this procedure may construct a self-intersecting surface.