6 return u * (c1 - c0) + c0;
10 DCELL c00, DCELL c01, DCELL c10, DCELL c11)
20 return (u * (u * (u * (c3 - 3 * c2 + 3 * c1 - c0) +
21 (-c3 + 4 * c2 - 5 * c1 + 2 * c0)) + (c2 - c0)) + 2 * c1) / 2;
25 DCELL c00, DCELL c01, DCELL c02, DCELL c03,
26 DCELL c10, DCELL c11, DCELL c12, DCELL c13,
27 DCELL c20, DCELL c21, DCELL c22, DCELL c23,
28 DCELL c30, DCELL c31, DCELL c32, DCELL c33)