pub unsafe extern "C" fn sfcgal_geometry_visibility_point(
polygon: *const sfcgal_geometry_t,
point: *const sfcgal_geometry_t,
) -> *mut sfcgal_geometry_t
pub unsafe extern "C" fn sfcgal_geometry_visibility_point(
polygon: *const sfcgal_geometry_t,
point: *const sfcgal_geometry_t,
) -> *mut sfcgal_geometry_t