If you want to create 2D physics-driven games and applications, Box2D is the best choice available. Box2D is a 2D rigid body simulation library used in some of the most successful games, such as Angry Birds and Tiny Wings on iPhone or Totem Destroyer and Red Remover on Flash. Google them, and you'll see a lot of enthusiastic reviews.
Before we dive into the Box2D World, let me explain what is a rigid body . It's a piece of matter that is so strong that it can't be bent in any way. There is no way to modify its shape, no matter how hard you hit it or throw it. In the real world, you can think about something as hard as a diamond, or even more. Matter coming from outer space that can't be deformed.
Box2D only manages rigid bodies, which will be called just "bodies" from now on, but don't worry, you will also be able to simulate stuff which normally is not rigid, such as bouncing balls.
Let's see what you are about to learn in this chapter:
Downloading and installing Box2D for Flash
Including required classes in your Flash projects
Creating your first Box2D World
Understanding gravity and sleeping bodies
Running your first empty simulation, handling time steps, and constraints
By the end of the chapter, you will be able to create an empty, yet running world where you can build your awesome physics games.
