It depends on what you want to do. Here's a simple example: if you want to write games with Unity then basic maths will see you just fine, but if you wanted to write your own competitor to Unity, then you'd need a higher level of maths. Same applies to OGRE, and Bullet, and... the list goes on.

FlexyCore tried the same thing a few years ago with iSpectrum: http://www.flexycore.com/ispectrum-overview.html .They even made the source available:http://www.in-the-box.org/ .

Also sounds like the stuff from eyeSight. I used this a few years ago (on Symbian): http://www.eyesight-tech.com/technology/

My not-so-old house has toilets with a "continental shell" and a tap to do the flushing, So after the Kenyans get their newfangled MicroToilets, I'd like one of their old ones to replace my shitty (pun intended) Western-style pot.