#define NUMCTLPOINTS   7  /* number of control points */
#define ORDER          3  /* order */
#define LENKNOTVEC	   (NUMCTLPOINTS + ORDER)  /* length knotvector */
#define STRIDE         3  /* values per control point: X, Y, weight */

/* Knotvector: 5 knots, so 4 segments (of equal reach). */
GLfloat knots[LENKNOTVEC] = {0.00, 0.00, 0.00,  /* knot 1, 3-fold */
                                     0.25,              /* knot 2 */
                                     0.50, 0.50,        /* knot 3, 2-fold */
                                     0.75,              /* knot 4 */
                                     1.00, 1.00, 1.00}; /* knot 5, 3-fold */

/* Control points, per point: X, Y, weight. */
GLfloat ctlPoints[NUMCTLPOINTS*STRIDE] = { 1.0,  0.0,  1.0,
                                           1.0,  1.0,  0.5,
                                          -1.0,  1.0,  0.5,
                                          -1.0,  0.0,  1.0,
                                          -1.0, -1.0,  0.5,
                                           1.0, -1.0,  0.5,
                                           1.0,  0.0,  1.0};