*/
  public void frustum (double left, double right, double bottom, double top,
                       double near, double far) {

    RequestOutputStream o = display.out;
    synchronized (o) {
      begin_render_request (o, 175, 52);
      o.write_double (left);
      o.write_double (right);
      o.write_double (bottom);
      o.write_double (top);
      o.write_double (near);
      o.write_double (far);
    }
  }