typedef int PK_blend_check_su_X_t;


This data type selects which of the new surfaces will be checked for
self-intersections during the blending operation. It has three values:

    PK_blend_check_su_X_no_c          don't check any surfaces
    PK_blend_check_su_X_not_bsurf_c   check all surfaces except B-surfaces
    PK_blend_check_su_X_yes_c         check all surfaces