typedef int PK_knot_type_t;


This field can take any one of the following values.
    PK_knot_unset_c            : The type has not been calculated.
    PK_knot_non_uniform_c      : The knot set is general non uniform.
    PK_knot_uniform_c          : The knots are uniformly spaced.
    PK_knot_quasi_uniform_c    : The first and last knots have
                                   multiplicity degree+1, and the
                                   remainder have multiplicity 1, with
                                   equal spacing.
    PK_knot_piecewise_bezier_c : The first and last knots have
                                   multiplicity degree+1 and the
                                   remainder have multiplicity degree,
                                   with equal spacing.
    PK_knot_bezier_ends_c      : The first and last knots have
                                   multiplicity degree+1.  In other
                                   respects the knot set is non uniform.
    PK_knot_smooth_seam_c      : Applicable only to PK_BCURVE_create.
                                   Modifications will be made to the curve
                                   input data to guarantee the end and start
                                   of the curve meet sufficiently smoothly to
                                   ensure periodic parameterisation. This is
                                   done by repeating the first degree vertices
                                   at the end and by matching knot intervals.