Line of sight

[na_th_an]

I've used it in several games and it works quite fine. A couple of pixels aren't big deal when it comes to fast-paced action. Square-rooting is quite slow for something you need to do in every frame.

I think the formula was derived from extracting the Taylor series related to sqrt X (<!-- m --><a class="postlink" href="http://en.wikipedia.org/wiki/Taylor_series">http://en.wikipedia.org/wiki/Taylor_series</a><!-- m -->). If you need more accurate results, you can keep extending it with more elements.