title: Does OpenCV offer a squared norm function for cv::Point?
body: <p>I have to check several distances between points against a distance threshold. What I can do is taking the square of my threshold and compare it with the squared norm of <code>(a-b)</code>, where <code>a</code> and <code>b</code> are the points I am checking.</p>
  
  <p>I know about <a href="http://docs.opencv.org/modules/core/doc/operations_on_arrays.html#norm" rel="noreferrer"><code>cv::norm</code></a> function, but I wonder if there exists a version that doesn't compute the square root (and therefore is faster) or if I should implement it manually. </p>