A challenging review
Reviewing code in a book is a strange concept; after all, you can just flip back to the earlier chapters to review what you've learned, so why bother to reiterate that now? At the same time, I've taught a lot of classes, and if there's one thing that's consistent, it's that sometimes smart students sit quietly, listen, nod, and then leave the classroom without understanding anything that you've just said. The only way to get an understanding is to take the knowledge we've practiced so far and build something upon it. Fortunately, we have just the thing.
What happened to the dog?
In Chapter 2, Drawing Sprites, we did a quick game design session where we described how our little Red Hat Boy (RHB) would be chasing his dog, who was startled by a cat. Yet, in the proceeding nine chapters, there has been no sign of the dog. Simply put, adding the dog, and a cat, requires very little that you don't already know how to do and...