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


Translation is stored as a three-dimensional vector inside a 4 X 4 matrix. The translation component of the matrix describes how much to move an object on each axis. Because we decided to use Row Major matrices, translation is stored in elements 41, 42, and 43 of the matrix:

Getting Ready

We're going to implement three functions: one to retrieve the translation already stored inside a 4 X 4 matrix, one to return a translation matrix given x, y, and z components, and one to return a translation matrix given the same x, y, and z components packed inside a vec3. When building any type of matrix, we start with the identity matrix and modify elements. We do this because the identity matrix has no effect on multiplication. The unused elements of a translation matrix should not affect rotation or scale; therefore we leave the first three rows the same as the identity matrix.

How to do it…

Follow these steps to set and retrieve the translation of a matrix:

  1. Add the declaration for all of...