I just recently ordered and received Real-Time Collision Detection from Amazon, and it was worth every penny. Collision detection was never something I was never particularly interested in, and in that past I was always willing to just leave it all up to a physics package to handle. But as anyone else working on an XNA game for the 360 knows, a physics engine isn’t really a practical option this time around. I’ve had some basic stuff working for a long time now (thanks to Fabio Policarpo’s BoxCollider), but my level designer has made some requests that have led me to finally dig in and start making my system robust while keeping it performance. Fortunately the book I ordered cam to the rescue: it has some fantastic overviews and demonstration of just about every aspect of collision detection. The explanations are concise and get right to the important points, and derivation of the mathematical formulas are always followed by a sample implementation in C++ (If you’re like me and you hate pseudo-code, then this truly is a wonderful thing).
So kids if you don’t have it yet…go get this book.