Book Image

Box2D for Flash Games

Book Image

Box2D for Flash Games

Overview of this book

Physics games are getting more and more popular, and Box2D is the best choice if you are looking for a free, stable and robust library to handle physics. With Box2D you can create every kind of 2D physics game, only coding is not the fun part, but the game itself. "Box2D for Flash Games" will guide you through the process of making a Flash physics game starting from the bare bones and taking you by hand through complex features such as forces, joints and motors. As you are learning, your game will have more and more features, like the physics games you are used to playing. The book analyzes two of the most played physics games, and breaks them down to allow readers to build them from scratch in a step-by-step approach. By the end of the book, you will learn how to create basic primitive bodies as well as complex, compound bodies. Motors will give life to cars, catapults and siege machines firing bullets, while a complete collision management will make your game look even more realistic. If you want to make full Flash games with physics, then Box2D for Flash Games will guide you through the entire process of making a Flash physics game.
Table of Contents (15 chapters)
Box2D for Flash Games
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Creating compound bodies


The idol is the main character in Totem Destroyer, we can't represent it with just a box, or the curse of the totem will persecute us forever.

I was thinking about something like the following figure:

This is what I call an idol, and this is what we are going to build with Box2D.

On the left-hand side, the outline of the bodies forming the idol, and on the right-hand side the finished idol silhouette.

The first thing you can see is that the idol is made by more than one body joined together to create a single, complex body. Remember Box2D only works with convex polygons. Unlike totem bricks, which are just single boxes stacked, we need to merge all the idol objects in some way.

Easy things first. We'll start with the vertical box that we already know how to build, and we are going to build it in the Main function just after building the last totem brick.

public function Main() {
  world=new b2World(new b2Vec2(0,5),true);
  debugDraw();
  brick(275,435,30,30);
  brick(365...