I'm not the author of the original comment, but when I was in high school I found the Graphics Programming Black Book to be useful for understanding graphics primitives and how they can be implemented in software. It's available for free online: http://www.gamedev.net/page/resources/_/technical/graphics-p...
Thanks, this is a great read (even though parts seem dated, for example, the TOC has chapters on the 386 and 486), I'm surprised that I haven't stumbled upon it before.
The latest Core i7 still has all the same instructions as a 386 or 486, so while these days you'd probably use SIMD instructions, the code will still run and run very, very fast.