static double bicubic(kernel *k, double x) { return (1.0/6.0) * ( bc_pow3(x + 2) - 4 * bc_pow3(x + 1) + 6 * bc_pow3(x) - 4 * bc_pow3(x - 1)); }
static double bicubic(params *p, double x) { return (1.0/6.0) * ( bc_pow3(x + 2) - 4 * bc_pow3(x + 1) + 6 * bc_pow3(x) - 4 * bc_pow3(x - 1)); }