The bible of graphics programming, everything with software rendering,
"Computer Graphics: Principles and Practice"
https://www.informit.com/store/computer-graphics-principles-...
Yeah, it is a steep price as many academia books, maybe you can find it on a library nearby, as its first edition was in 1982.
This book is quite old. I would argue that Realtime Rendering 4th edition is the better book. Bonus points if you pair it with some online resources to get a deeper understanding of the topics (but the textbook contains follow up material for all discussed topics).