Game Programming Using Qt: Beginner's Guide

Table of Contents

Game Programming Using Qt

Credits

About the Authors

About the Reviewers

www.PacktPub.com

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Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Sections

Time for action – heading

What just happened?

Pop quiz – heading

Have a go hero – heading

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Introduction to Qt

The cross-platform programming

What just happened?

Qt Platform Abstraction

Supported platforms

A journey through time

New in Qt 5

Restructured codebase

Qt Essentials

Qt Add-ons

Qt Quick 2.0

Meta-objects

C++11 support

Choosing the right license

An open source license

A commercial license

Summary

2. Installation

Installing the Qt SDK

Time for action – installing Qt using an online installer

What just happened?

Setting up Qt Creator

Time for action – loading an example project

What just happened?

Time for action – running the Affine Transformations project

What just happened?

Building Qt from sources

Time for action – setting up Qt sources using Git

What just happened?

Time for action – configuring and building Qt

What just happened?

Summary

3. Qt GUI Programming

Windows and dialogs

Creating a Qt project

Time for action – creating a Qt Desktop project

What just happened?

Adding child widgets to a window

Managing widget content

Time for action – implementing a tic-tac-toe game board

What just happened?

Qt meta-objects

Signals and slots

Pop quiz – making signal-slot connections

Time for action – functionality of a tic-tac-toe board

Properties

Declaring a property

Using a property

Time for action – adding properties to the board class

What just happened?

Designing GUIs

Time for action – designing the game configuration dialog

What just happened?

Time for action – polishing the dialog

Accelerators and label buddies

The tab order

Signals and slots

What just happened?

Using designer forms

Direct approach

The multiple-inheritance approach

The single inheritance approach

Time for action – the logic of the dialog

An application's main window

The Qt resource system

Time for action – the main window of the application

What just happened?

Time for action – adding a pull-down menu

What just happened?

Time for action – creating a toolbar

What just happened?

Time for action – filling in the central widget

What just happened?

Time for action – putting it all together

What just happened?

Have a go hero – extending the game

Pop quiz – using widgets

Summary

4. Qt Core Essentials

Text handling

Manipulating strings

Encoding and decoding text

Basic string operations

The string search and lookup

Dissecting strings

Converting between numbers and strings

Using arguments in strings

Regular expressions

Time for action – a simple quiz game

What just happened?

Extracting information out of a string

Finding all pattern occurrences

Data storage

Files and devices

Traversing directories

Getting access to the basic file

Devices

Time for action – implementing a device to encrypt data

What just happened?

Have a go hero – a GUI for the Caesar cipher

Text streams

Data serialization

Binary streams

Time for action – serialization of a custom structure

What just happened?

XML streams

Time for action – implementing an XML parser for player data

What just happened?

Have a go hero – an XML serializer for player data

JSON files

Time for action – the player data JSON serializer

Time for action – implementing a JSON parser

What just happened?

QSettings

Pop quiz – Qt core essentials

Summary

5. Graphics with Qt

Raster painting

Painter attributes

Widget painting

Time for action – custom-painted widgets

What just happened?

Time for action – transforming the viewport

What just happened?

Time for action – drawing an oscillogram

Input events

Time for action – making oscillograms selectable

Have a go hero – reacting only to the left mouse button

Working with images

Loading

Modifying

Painting

Painting text

Static text

Rich text

Optimized drawing

Time for action – optimizing oscillogram drawing

What just happened?

Have a go hero – implementing a double-buffered oscillogram

Time for action – developing the game architecture

What just happened?

Time for action – implementing the game board class

What just happened?

Time for action – understanding the ChessView class

What just happened?

Time for action – rendering the pieces

What just happened?

Time for action – making the chess game interactive

What just happened?

Time for action – connecting the game algorithm

What just happened?

Have a go hero – implementing the UI around the chess board

Have a go hero – connecting a UCI-compliant chess engine

OpenGL

Introduction to OpenGL with Qt

Time for action – drawing a triangle using Qt and OpenGL

Time for action – scene-based rendering

What just happened?

Time for action – drawing a textured cube

Have a go hero – animating a cube

Modern OpenGL with Qt

Shaders

Time for action – shaded objects

GL buffers

Off-screen rendering

Summary

6. Graphics View

Graphics View architecture

Items

Parent child relationship

Appearance

Time for action – creating a black, rectangular item

What just happened?

Time for action – reacting to an item's selection state

What just happened?

Time for action – making the item's size definable

What just happened?

Have a go hero – customizing the item

Standard items

Coordinate system of the items

Time for action – creating items with different origins

What just happened?

Time for action – rotating an item

What just happened?

Have a go hero – applying multiple transformations

Scenes

Adding items to the scene

Time for action – adding an item to a scene

What just happened?

Interacting with items on the scene

Rendering

Time for action – rendering the scene's content to an image

What just happened?

Have a go hero – rendering only specific parts of a scene

Coordinate system of the scene

Time for action – transforming parent items and child items

What just happened?

Have a go hero – playing with the z value

View

Time for action – putting it all together!

What just happened?

Showing specific areas of the scene

Transforming the scene

Time for action – creating an item where transformations can easily be seen

What just happened?

Time for action – implementing the ability to scale the scene

What just happened?

Time for action – implementing the ability to move the scene

What just happened?

Time for action – taking the zoom level into account

What just happened?

Questions you should keep in mind

The jumping elephant or how to animate the scene

The game play

The player item

Time for action – creating an item for Benjamin

What just happened?

The playing field

The scene

Time for action – making Benjamin move

What just happened?

Parallax scrolling

Time for action – moving the background

What just happened?

Have a go hero – adding new background layers

QObject and items

Time for action – using properties, signals, and slots with items

Property animations

Time for action – using animations to move items smoothly

What just happened?

Have a go hero – letting the scene handle Benjamin's jump

Time for action – keeping multiple animations in sync

What just happened?

Item collision detection

Time for action – making the coins explode

What just happened?

Setting up the playing field

Have a go hero – extending the game

A third way of animation

Widgets inside Graphics View

Optimization

A binary space partition tree

Caching the item's paint function

Optimizing the view

Pop quiz – mastering Graphics View

Summary

7. Networking

QNetworkAccessManager

Downloading files over HTTP

Time for action – downloading a file

Have a go hero – extending the basic file downloader

Error handling

Time for action – displaying a proper error message

Downloading files over FTP

Downloading files in parallel

The finished signal

Time for action – writing the OOP conform code using QSignalMapper

What just happened?

The error signal

The readyRead signal

The downloadProgress method

Time for action – showing the download progress

What just happened?

Using a proxy

Connecting to Google, Facebook, Twitter, and co.

Time for action – using Google's Distance Matrix API

Time for action – constructing the query

Time for action – parsing the server's reply

Have a go hero – choosing XML as the reply's format

Controlling the connectivity state

QNetworkConfigurationManager

QNetworkConfiguration

QNetworkSession

QNetworkInterface

Communicating between games

Time for action – realizing a simple chat program

The server – QTcpServer

Time for action – setting up the server

What just happened?

Time for action – reacting on a new pending connection

What just happened?

Time for action – forwarding a new message

Have a go hero – using QSignalMapper

Time for action – detecting a disconnect

What just happened?

The client

Time for action – setting up the client

What just happened?

Time for action – receiving text messages

Time for action – sending text messages

Have a go hero – extending the chat with a user list

Improvements

Using UDP

Time for action – sending a text via UDP

Have a go hero – connecting players of the Benjamin game

Pop quiz – test your knowledge

Summary

8. Scripting

Why script?

The basics of Qt Script

Evaluating JavaScript expressions

Time for action – creating a Qt Script editor

What just happened?

Time for action – sandboxed script evaluation

What just happened?

Integrating Qt and Qt Script

Exposing objects

Time for action – employing scripting for npc AI

What just happened?

Have a go hero – extending the Dungeons & Dragons game

Exposing functions

Exposing C++ functions to scripts

Exposing script functions to C++

Time for action – storing the script

What just happened?

Time for action – providing an initialization function

What just happened?

Time for action – implementing the heartbeat event

What just happened?

Have a go hero – defending against attacks

Using signals and slots in scripts

Have a go hero – triggering defense using signals and slots

Creating Qt objects in scripts

Error recovery and debugging

Extensions

The other Qt JavaScript environment

Alternatives to JavaScript

Python

Time for action – writing a Qt wrapper for embedding Python

What just happened?

Time for action – converting data between C++ and Python

What just happened?

Have a go hero – implementing the remaining conversions

Time for action – calling functions and returning values

What just happened?

Have a go hero – wrapping Qt objects into Python objects

Pop quiz – scripting

Summary

9. Qt Quick Basics

Fluid user interfaces

Declarative UI programming

Element properties

Group properties

Object hierarchies

Time for action – creating a button component

What just happened?

Time for action – adding button content

What just happened?

Time for action – sizing the button properly

What just happened?

Time for action – making the button a reusable component

What just happened?

Event handlers

Mouse input

Time for action – making the button clickable

What just happened?

Time for action – visualizing button states

What just happened?

Time for action – notifying the environment about button states

What just happened?

Touch input

Time for action – dragging an item around

What just happened?

Time for action – rotating and scaling a picture by pinching

What just happened?

Have a go hero – rotating and scaling with a mouse

Keyboard input

Have a go hero – practicing key-event propagation

Using components in Qt Quick

Time for action – a simple analog clock application

What just happened?

Time for action – adding needles to the clock

What just happened?

Time for action – making the clock functional

What just happened?

Dynamic objects

Using components in detail

Creating objects on request

Delaying item creation

Accessing your item's component functionality

Imperative painting

Time for action – preparing Canvas for heartbeat visualization

What just happened?

Time for action – drawing a heartbeat

What just happened?

Time for action – making the diagram more colorful

What just happened?

Qt Quick and C++

Creating QML objects from C++

Pulling QML objects to C++

Pushing C++ objects to QML

Time for action – self-updating car dashboard

What just happened?

Time for action – grouping engine properties

What just happened?

Extending QML

Registering classes as QML elements

Time for action – making CarInfo instantiable from QML

What just happened?

Custom Qt Quick items

OpenGL items

Time for action – creating a regular polygon item

What just happened?

Have a go hero – creating a supporting border for RegularPolygon

Painted items

Time for action – creating an item for drawing outlined text

What just happened?

Summary

10. Qt Quick

Bringing life into static user interfaces

Animating elements

Generic animations

Time for action – scene for an action game

What just happened?

Time for action – animating the sun's horizontal movement

What just happened?

Composing animations

Time for action – making the sun rise and set

What just happened?

Non-linear animations

Time for action – improving the path of the sun

What just happened?

Property value sources

Time for action – adjusting the sun's color

What just happened?

Time for action – furnishing sun animation

What just happened?

Have a go hero – animating the sun's rays

Behaviors

Time for action – animating the car dashboard

What just happened?

States and transitions

More animation types

Quick game programming

Game loops

Time for action – character navigation

What just happened?

Time for action – another approach to character navigation

What just happened?

Have a go hero – polishing the animation

Time for action – generating coins

What just happened?

Sprite animation

Time for action – implementing simple character animation

What just happened?

Time for action – animating characters using sprites

What just happened?

Time for action – adding jumping with sprite transitions

What just happened?

Have a go hero – making Benjamin wiggle his tail in anticipation

Parallax scrolling

Time for action – revisiting parallax scrolling

What just happened?

Have a go hero – vertical parallax sliding

Collision detection

Time for action – collecting coins

What just happened?

Notes on collision detection

Eye candy

Auto-scaling user interfaces

Graphical effects

Have a go hero – the blur parallax scrolled game view

Particle systems

Tuning the emitter

Rendering particles

Making particles move

Time for action – vanishing coins spawning particles

What just happened?

Summary

A. Pop Quiz Answers

Chapter 3, Qt GUI Programming

Pop quiz – making signal-slot connections

Pop quiz – using widgets

Chapter 4, Qt Core Essentials

Pop quiz – Qt core essentials

Chapter 6, Graphics View

Pop quiz – mastering Graphics View

Chapter 7, Networking

Pop quiz – testing your knowledge

Chapter 8, Scripting

Pop quiz – scripting

Chapter 11, Miscellaneous and Advanced Concepts

Pop quiz – testing your knowledge

Index

Game Programming Using Qt

Game Programming Using Qt

Copyright © 2016 Packt Publishing

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First published: January 2016

Production Reference: 1210116

Published by Packt Publishing Ltd.

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ISBN 978-1-78216-887-4

www.packtpub.com

Credits

Authors

Witold Wysota

Lorenz Haas

Reviewers

Simone Angeloni

Rahul De

Pooya Eimandar

Shaveen Kumar

M. Cihan Özer

Acquisition Editor

Vinay Argekar

Content Development Editor

Pooja Mhapsekar

Technical Editor

Mrunmayee Patil

Copy Editor

Neha Vyas

Project Coordinator