PK_ERROR_code_t   PK_SURF_ask_uvbox
(
--- received arguments ---
PK_SURF_t         surf,     --- a surface

--- returned arguments ---
PK_UVBOX_t *const uvbox     --- parametric bounds of the surf
)


This function returns a uvbox indicating the parametric bounds of the
given surface.  If the surface has an infinite parameter range,  then for that
parameter, a finite range will be returned which is sufficient to contain
that part of the surface inside the size box.