-void wx_quadratic_spline(double a1, double b1, double a2, double b2, double a3, double b3, double a4,
- double b4)
-{
- register double xmid, ymid;
- double x1, y1, x2, y2, x3, y3, x4, y4;
-
- wx_clear_stack();
- wx_spline_push(a1, b1, a2, b2, a3, b3, a4, b4);
-
- while (wx_spline_pop(&x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)) {
- xmid = (double)half(x2, x3);
- ymid = (double)half(y2, y3);
- if (fabs(x1 - xmid) < THRESHOLD && fabs(y1 - ymid) < THRESHOLD &&
- fabs(xmid - x4) < THRESHOLD && fabs(ymid - y4) < THRESHOLD) {
- wx_spline_add_point( x1, y1 );
- wx_spline_add_point( xmid, ymid );
- } else {
- wx_spline_push(xmid, ymid, (double)half(xmid, x3), (double)half(ymid, y3),
- (double)half(x3, x4), (double)half(y3, y4), x4, y4);
- wx_spline_push(x1, y1, (double)half(x1, x2), (double)half(y1, y2),
- (double)half(x2, xmid), (double)half(y2, ymid), xmid, ymid);
- }