parts 2 and 3 to this article:

http://fgiesen.wordpress.com/2011/07/02/a-trip-through-the-g...

http://fgiesen.wordpress.com/2011/07/03/a-trip-through-the-g...

For those who don't know, the title is reference to a famous series of articles by Jim Blinn called "A Trip Down the Graphics Pipeline".

  http://penguin.ewu.edu/cscd470/2009/JimBlinnsCorner/

Way too much useful information, I could spend hours reading this blog :)