Book Image

iOS Game Programming Cookbook

Book Image

iOS Game Programming Cookbook

Overview of this book

Table of Contents (19 chapters)
iOS Game Programming Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Using vectors


We will be using vector math frequently when designing the AI for our games. Vectors are used everywhere, from calculating which direction a game agent should shoot its gun in, to expressing the inputs and outputs of an artificial neural network. You should know them well.

Let's take a point P as follows:

P = (x, y)

A two-dimensional vector looks almost the same when written, as follows:

V = (x, y)

However, although similar, a vector represents two components: direction and magnitude. The right-hand side of the following diagram shows the vector (9, 6) situated at the origin:

The bearing of the arrow shows the direction of the vector, and the length of the line represents the magnitude of the vector. A vector can represent the velocity of a vehicle. The magnitude of the vector represents the speed of the vehicle, and the direction represents the heading of the vehicle.

That's quite a lot of information from just two numbers (x, y). Vectors aren't restricted to two dimensions either...