Command line progress UI

Congrats on the fun work. The bonus chapters Jamis has posted over the last year or two have been super-fun, and very frustrating at moments, lol! It's a good book, checking the errata is important, as there are typically errors in any given imprint of the book, both ebook and print-copy (which I have). I recommend an abundant use of tools, such as a code-flow analyzer, especially. Definitely I recommend independent reading and study of, ooh, a bunch of stuff, but if you don't really understand Linear Algebra thre are many frustrating hours of chasing down inscrutable design flaws on one's own part. Properly understanding matrix and vector maths (and what cross and dot *really* are - which the book is wafer-thin on. Learning this stuff is a rabbit-hole down fundamental maths and physics, which one needs to be inspired to really learn to write a really competent ray engine). You're nearly at completion of Jamis's guide, sans the bonus chapters, but continue to have fun...