Book Image

Game Physics Cookbook

By : Gabor Szauer
Book Image

Game Physics Cookbook

By: Gabor Szauer

Overview of this book

Physics is really important for game programmers who want to add realism and functionality to their games. Collision detection in particular is a problem that affects all game developers, regardless of the platform, engine, or toolkit they use. This book will teach you the concepts and formulas behind collision detection. You will also be taught how to build a simple physics engine, where Rigid Body physics is the main focus, and learn about intersection algorithms for primitive shapes. You’ll begin by building a strong foundation in mathematics that will be used throughout the book. We’ll guide you through implementing 2D and 3D primitives and show you how to perform effective collision tests for them. We then pivot to one of the harder areas of game development—collision detection and resolution. Further on, you will learn what a Physics engine is, how to set up a game window, and how to implement rendering. We’ll explore advanced physics topics such as constraint solving. You’ll also find out how to implement a rudimentary physics engine, which you can use to build an Angry Birds type of game or a more advanced game. By the end of the book, you will have implemented all primitive and some advanced collision tests, and you will be able to read on geometry and linear Algebra formulas to take forward to your own games!
Table of Contents (27 chapters)
Game Physics Cookbook
About the Author
About the Reviewer
Customer Feedback

Rigidbody Modifications

We will create a new Rigidbody subclass that has volume. This class will either be a sphere or a box. Before we make this subclass, we need to slightly modify the Rigidbody class so that we can identify the type of rigidbody we are dealing with.

As we will create a new subclass of Rigidbody, we need a way to differentiate this new class from a particle. We will introduce the HasVolume helper function that will let us know if a rigid body has volume or not.

Getting ready

This class will be a rigidbody that has a shape and some volume. We will also add a type identifier to the Rigidbody class. With this identifier, we will be able to tell if a rigidbody is a particle or if it has some volume.

How to do it…

Follow the mentioned steps to add type information to the Rigidbody class:

  1. Add the following type definitions to Rigidbody.h. These constants will let us know what type of rigidbody each rigidbody subclass is: