throw new Error("not implemented");
return Math.max(Line2D.ptSegDistSq(x1, y1, x2, y2, cx1, cy1), Line2D.ptSegDistSq(x1, y1, x2, y2, cx2, cy2));
  public static double getFlatnessSq(double x1, double y1, double cx1,                                     double cy1, double cx2, double cy2,                                     double x2, double y2)  {    // XXX Implement.    throw new Error("not implemented");  }