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 – grouping engine properties


QML has a concept called grouped properties. These are properties of an object that contain a group of "sub-properties." You already know a number of them–the border property of the Rectangle element or the anchors property of the Item element, for example. Let's see how to define such properties for our exposed object.

Create a new QObject-derived class and call it CarInfoEngine. Move the property definitions of rpm and gear to that new class.Add the following property declaration to CarInfo:

Q_PROPERTY(Object* engine READ engine NOTIFY engineChanged)

Implement the getter and the private field:

    QObject* engine() const { return m_engine; }
private:
    CarInfoEngine *m_engine;

We are not going to use the signal right now; however, we had to declare it otherwise QML would complain we were binding expressions that depend on properties that are non-notifiable:

signals:
    void engineChanged();

Initialize m_engine in the constructor of CarInfo:

m_engine...