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
About the Author
About the Reviewers

Chapter 6. Joints and Motors

All kinds of bodies you've met until now have something in common: they are free and do not depend on each other, unless they collide. Sometimes you may want to constrain bodies to each other. If you think about Crush the Castle game, the siege machine is made by a series of bodies connected together in some way.

Box2D allows us to create constraints between bodies with joints . Joints allow us to build complex objects and give more realism to our games.

In this chapter you will learn how to create the most common types of joints, and you will discover, among other things, how to:

  • Pick, drag, and drop bodies with mouse joints

  • Keep bodies at a given distance with distance joints

  • Make bodies rotate using revolute joints

  • Give life to your games using motors

By the end of the chapter, you will be able to destroy the Angry Birds level with a siege machine.

Anyway, joints can also be used to interact with bodies, by picking and dragging them with the mouse. This is the first...