Book Image

Game Programming Using Qt: Beginner's Guide

By : Lorenz Haas, Witold Wysota, Witold Wysota, Lorenz Haas
Book Image

Game Programming Using Qt: Beginner's Guide

By: Lorenz Haas, Witold Wysota, Witold Wysota, Lorenz Haas

Overview of this book

Qt is the leading cross-platform toolkit for all significant desktop, mobile, and embedded platforms and is becoming more popular by the day, especially on mobile and embedded devices. Despite its simplicity, it's a powerful tool that perfectly fits game developers’ needs. Using Qt and Qt Quick, it is easy to build fun games or shiny user interfaces. You only need to create your game once and deploy it on all major platforms like iOS, Android, and WinRT without changing a single source file. The book begins with a brief introduction to creating an application and preparing a working environment for both desktop and mobile platforms. It then dives deeper into the basics of creating graphical interfaces and Qt core concepts of data processing and display before you try creating a game. As you progress through the chapters, you’ll learn to enrich your games by implementing network connectivity and employing scripting. We then delve into Qt Quick, OpenGL, and various other tools to add game logic, design animation, add game physics, and build astonishing UI for the games. Towards the final chapters, you’ll learn to exploit mobile device features such as accelerators and sensors to build engaging user experiences. If you are planning to learn about Qt and its associated toolsets to build apps and games, this book is a must have.
Table of Contents (18 chapters)
Game Programming Using Qt
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Time for action – implementing a device to encrypt data


Let's implement a really simple device that encrypts or decrypts the data that is streamed through it using a very simple algorithm—the Caesar cipher. What it does is that when encrypting, it shifts each character in the plaintext by a number of characters defined by the key and does the reverse when decrypting. Thus, if the key is 2 and the plaintext character is a, the ciphertext becomes c. Decrypting z with the key 4 will yield the value v.

We will start by creating a new empty project and adding a class derived from QIODevice. The basic interface of the class is going to accept an integer key and set an underlying device that serves as the source or destination of data. This is all simple coding that you should already understand, so it shouldn't need any extra explanation, as shown:

class CaesarCipherDevice : public QIODevice
{
    Q_OBJECT
    Q_PROPERTY(int key READ key WRITE setKey)
public:
    explicit CaesarCipherDevice(QObject...