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
Credits
About the Author
Acknowledgements
About the Reviewer
Acknowledgements
www.PacktPub.com
Customer Feedback
Preface
Index

Triangle


Triangles are one of the most important primitive shapes for 3D graphics. A triangle can be represented by three non linear points. Triangles are special because they are co-planar. This means that the three points of a triangle always lie on the same plane:

Getting ready

We are going to implement a triangle that is defined by three points. To make this structure more convenient to use, we can declare an anonymous union. This union will let us access the members of the Triangle struct in different ways.

How to do it

Follow these steps to implement a 3D triangle:

  1. Declare the Triangle structure in Geometry3D.h:

    typedef struct Triangle {
       union {
  2. The points of a triangle should be accessible as three separate points: a, b and c:

           struct {
               Point a;
               Point b;
               Point c;
           };
  3. One of the alternate methods to access the points of a triangle is as an array of points:

           Point points[3];
  4. The final way of accessing the points of a triangle is as a linear...