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 – keeping multiple animations in sync


If you have a look at how the coins (their class being called Coin) are created, you see similar structures. They inherit from QObject and QGraphicsEllipseItem and define two properties: opacity of type qreal and rect of type QRect. This is done only by the following code:

Q_PROPERTY(qreal opacity READ opacity WRITE setOpacity)
Q_PROPERTY(QRectF rect READ rect WRITE setRect)

No function or slot was added because we simply used built-in functions of QGraphicsItem and "redeclared" them as properties. Then, these two properties are animated by two QPropertyAnimation objects. One fades the coin out, while the other scales the coin in. To ensure that both animations get started at the same time, we use QParallelAnimationGroup as follows:

QPropertyAnimation *fadeAnimation = /* set up */
QPropertyAnimation *scaleAnimation = /* set up */
QParallelAnimationGroup *group = new QParallelAnimationGroup(this);
group->addAnimation(fadeAnimation);
group...