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 – revisiting parallax scrolling


We will implement parallax scrolling with a set of layers that move in the direction opposite to the one the player is moving in. Therefore, we will need a definition of the scene and a moving layer.

Create a new QML Document (Qt Quick 2). Call it ParallaxScene.qml. The scene will encompass the whole game "level" and will expose the position of the player to the moving layers. Put the following code in the file:

import QtQuick 2.2

Item {
  id: root
  property int currentPos
  x: -currentPos*(root.width-root.parent.width)/width
}

Then, create another QML Document (Qt Quick 2) and call it ParallaxLayer.qml. Make it contain the following definition:

import QtQuick 2.2

Item {
  property real factor: 0
  x: factor > 0 ? -parent.currentPos/factor - parent.x : 0
}

Now, let's use the two new element types in the main QML document. We'll take elements from the earlier scene definition and make them into different parallax layers—the sky, the trees,...