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

When Angry Birds meets Crush the Castle

What if birds had a siege machine? Let's explore this gameplay, but first let me explain which kind of siege machine I want to build using only distance and revolute joints.

The siege machine consists of two carts mounted on wheels. The first cart can be controlled by the player and acts as a truck tractor. The second cart is just a trailer but has something between a trebuchet and a morning star mounted on it.

A bit confused? Let me show you the prototype:

There is a lot to do, so let's start running. What do we need to include in our package?

  1. First, the same old classes, Joints included:

    import flash.display.Sprite;
    import Box2D.Dynamics.*;
    import Box2D.Collision.*;
    import Box2D.Collision.Shapes.*;
    import Box2D.Common.Math.*;
    import Box2D.Dynamics.Joints.*;
  2. And obviously the class-level variables you are already used to now:

    private var world:b2World;
    private var worldScale:Number=30;
  3. The beginning of this step is not that different...