INTRODUCTION

This is a great book!

There, I said it again! In the introduction to the original version of this book, I went on to clarify that the book's greatness wasn't necessarily a reflection of my own greatness, but of the fact that the book covered some great topics. It answered all the questions about animation in ActionScript that I had struggled with over the years, the questions that I had seen others struggle with, and the questions that people still e-mail me with. Even the answers aren't things that I dreamt up on my own, but discovered by searching, reading, and asking people far wiser and more educated than myself. OK, I'll take a little credit for assembling it all in a logical order and explaining things in what people tell me is a pretty understandable way. At any rate, my rather conceited opening statement has proven to have some merit, if sales figures and the feedback that many of you have given me personally are any indication. So, thanks for buying it, and thanks for the nice comments.

This version of the book is essentially the same book, converted to ActionScript 3. The same basic formulas and techniques are covered that were covered in the first version, in roughly the same order. I would have liked to get into some new, additional techniques, but there was little that I could really cut out of the existing text, and in fact, even covering those same basics takes up a lot more space in ActionScript 3, as virtually every example here is contained in its own full class. But although the same basic topics are covered, it was still quite a bit of work, considering the massive changes this version of ActionScript has brought us.

Yes, if you plan to read this book, plan to learn a little object-oriented programming. I was able to largely avoid the subject in the first version of the book, but this time I decided to abandon the timeline and dive into ActionScript 3 the way it was meant to be written—with classes. Although you may find that a bit scary if you haven't used classes or OOP before, I guarantee you that by the time you finish Chapter 4, you will have gotten the hang of programming with classes, and by the time you are halfway through the book, it will be old hat to you. And if you are already familiar with ActionScript 2 classes, this book should serve as a nice transition into ActionScript 3.

Other than that, I'll briefly repeat a few of the things I said in the introduction to the first version. First, that the example and techniques I give here are not the only or even necessarily the best way of doing things. I will say that they all do what they are supposed to, and most of them are pretty darned good, but if you feel you can improve on them, go for it.

Second, there are no start-to-finish full game tutorials or anything of the sort in here. It's more of a catalog of individual techniques. It's my belief that if you understand and can apply these techniques, you'll have no problem dreaming up plenty of cool things to create with them.

And finally, a point I'll make a few more times throughout the book (and have even been criticized for making too often) is that although I cover a lot of mathematical formulas and physics in the following chapters, I take a lot of liberties with them. The resulting formulas are designed to look realistic and run at a decent speed within Flash Player. But don't be surprised if you find a lot of discrepancies between what you see in this book and your college physics text book.

But enough introduction. As I also said in the first edition, this is a fun book! So dive in and enjoy!