It’s free and online! This is the book I wish I had when I started making games, and I want you to have it now!
I’ve only read the first few chapters, but already I can see this will be an indispensable resource for game programmers. The book is more low level, less on game design and more about the code at the heart of things, but it’s written beautifully and is chock full of examples.
It’s also all C++. So yeah, UE4 and stuff.