>This code contains a lot of knowledge VS use of pre-build APIs.

It contains a lot of general knowledge about 3D graphics, and absolutely 0 specific knowledge about the environment in which it's running. All he's accomplished by doing it this way is show off that he knows trig and prevent any of it from being hardware accelerated.

>If a programmer reads this code and understands how every part works

But he never will, because the code is illegible.

I hope this simplified version helps. I removed texture mapping and camera rotation, plus simplified a few unusual constructs.

https://gist.github.com/4195130

JsFiddled version: http://jsfiddle.net/ter7G/