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 needles to the clock


The next step is to add the hour, minute, and second needles to the clock. Let's start by creating a new component called Needle in a file called Needle.qml (remember that component names and files representing them need to start with a capital letter):

import QtQuick 2.0

Rectangle {
  id: root

  property int value: 0
  property int granularity: 60
  property alias length: root.height
  width: 2
  height: parent.height/2
  radius: width/2
  antialiasing: true
  anchors.bottom: parent.verticalCenter
  anchors.horizontalCenter: parent.horizontalCenter
  transformOrigin: Item.Bottom
  rotation: 360/granularity * (value % granularity)
}

Needle is basically a rectangle anchored to the center of its parent by its bottom edge, which is also the item's pivot. It also has value and granularity properties driving the rotation of the item, where value is the current value the needle shows and granularity is the number of different values it can display...