Book Image

OpenGL Game Development By Example

By : Stephen Madsen, Robert Madsen
Book Image

OpenGL Game Development By Example

By: Stephen Madsen, Robert Madsen

Overview of this book

OpenGL is one of the most popular rendering SDKs used to develop games. OpenGL has been used to create everything from 3D masterpieces running on desktop computers to 2D puzzles running on mobile devices. You will learn to apply both 2D and 3D technologies to bring your game idea to life. There is a lot more to making a game than just drawing pictures and that is where this book is unique! It provides a complete tutorial on designing and coding games from the setup of the development environment to final credits screen, through the creation of a 2D and 3D game. The book starts off by showing you how to set up a development environment using Visual Studio, and create a code framework for your game. It then walks you through creation of two games–a 2D platform game called Roboracer 2D and a 3D first-person space shooter game–using OpenGL to render both 2D and 3D graphics using a 2D coordinate system. You'll create sprite classes, render sprites and animation, and navigate and control the characters. You will also learn how to implement input, use audio, and code basic collision and physics systems. From setting up the development environment to creating the final credits screen, the book will take you through the complete journey of creating a game engine that you can extend to create your own games.
Table of Contents (19 chapters)
OpenGL Game Development By Example
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Mixing things up


Now that we are rendering in 3D, it isn't immediately obvious how we will render things in 2D. This is especially true of our user interface, which must be rendered on top of the 3D-scene and does not move or rotate with the rest of the world.

The trick to creating a 2D interface in a 3D world is to first render the 3D world, then switch modes in OpenGL, and then render the 2D content. The following image represents the 3D content that we need to render:

The next image represents the 2D text that we want to render:

We want the final result to be the combination of the 3D and 2D content, as shown in the following figure:

The saving state

State is a term that is used in many different ways in game programming. For example, we will create a state manager later in the chapter that will manage different states, or modes, in the game. Another way to define state is a set of conditions. For example, when we set things up to render in 3D, this is one set of conditions or state. When...