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 – adding an item to a scene


Let's have a first try and add an item to the scene:

QGraphicsScene scene;
QGraphicsRectItem *rectItem = new QGraphicsRectItem(0,0,50,50);
scene.addItem(rectItem);

What just happened?

Nothing complicated here. You create a scene, create an item of type QGraphicsRectItem, define the geometry of the item's rectangle, and then set the item to the scene by calling addItem(). Pretty straightforward. But what you do not see here is what this implies for the scene. The scene is now responsible for the added item! First of all, the ownership of the item is transferred to the scene. For you, this means that you do not have to worry about freeing the item's memory because deleting the scene also deletes all items associated with the scene. Now remember what we said about the destructor of a custom item: it must be virtual! QGraphicsScene operates with pointers to QGraphicsItem. Thus, when it deletes the assigned items, it does that by calling delete on the...