PK_ERROR_code_t      PK_CURVE_embed_in_surf
(
--- received arguments ---
PK_CURVE_t           curve,        --- curve
PK_SURF_t            surf,         --- surface

--- returned arguments ---
int           *const n_spcurves,   --- no. spcurves returned
PK_SPCURVE_t **const spcurves      --- spcurves
)


This function creates one or more spcurves by embedding a given curve in the
parameter space of a given surface.


Specific Errors:
    PK_ERROR_unsuitable_entity      curve is not a BCURVE
    PK_ERROR_bad_dimension          curve is not 2D
    PK_ERROR_unsuitable_entity      curve already underlies an SPCURVE
    PK_ERROR_invalid_geometry       curve does not make valid spcurves when
                                     embedded in surf (SERIOUS)


The curve must be a 2D BCURVE; that is it must either be a rational bcurve
with a vertex dimensionality of 3, or a non-rational bcurve with a vertex
dimensionality of 2. It must be an orphan.

Each of the resulting curves will satisfy the degeneracy and continuity
conditions for an spcurve.  See documentation of PK_SPCURVE_sf_t.