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

Containing rectangle

A containing rectangle is very similar to a containing circle. We will find the minimum non-oriented rectangle that contains a set of points. Depending on the shape being contained, a rectangle might be a tighter fit than a circle:

Getting ready

The ContainingRectangle function is going to be very similar to the ContainingCircle function. Just like ContainingCircle, this function will take an array of points, and a count of the number of points in the array. Given this set of input points, ContainingRectangle will return the minimum non-oriented rectangle that encompasses every point.

How to do it…

Follow these steps to create a function that will create a bounding rectangle from a set of points:

  1. Declare the ContainingRectangle function in Geometry2D.h:

    Rectangle2D ContainingRectangle(Point2D* pointArray, 
       int arrayCount);
  2. Implement the ContainingRectangle function in Geometry2D.cpp:

    Rectangle2D ContainingRectangle(Point2D* pointArray, 
       int arrayCount) {
       vec2 min =...