title: Other examples of magical calculations
body: <p>I have seen <a href="https://stackoverflow.com/questions/295579/fastest-way-to-determine-if-an-integers-square-root-is-an-integer">this topic here</a> about John Carmack's magical way to calculate square root, which refers to this article: <a href="http://www.codemaestro.com/reviews/9" rel="nofollow noreferrer">http://www.codemaestro.com/reviews/9</a>. This surprised me a lot, I just didn't ever realized that calculating sqrt could be so faster. </p>
  
  <p>I was just wondering what other examples of "magic" exist out there that computer games use to run faster.</p>
  
  <p><strong>UPDATE</strong>:
  John Carmack is not the author of the magic code. <a href="http://www.beyond3d.com/content/articles/8/" rel="nofollow noreferrer">This article</a> tells more. Thanks @moocha.</p>