Haxe Game Development Essentials E-Book

Jeremy McCurdy

• Herausgeber: Packt Publishing
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 200

Veröffentlichungsjahr: 2015

Beschreibung

Haxe is a powerful and high-level multi-platform language that's incredibly easy to learn. Used by thousands of developers and many high-profile companies, Haxe is quickly emerging as a forerunner in the area of cross-platform programming. OpenFL builds on top of Haxe to make developing for multiple platforms quick and painless. HaxeFlixel provides you with the tools you need to build amazing 2D games easier than ever before. Cross-platform development has been supercharged using the Haxe programming language, making it increasingly easy and hassle-free to develop multi-platform games.
If you've programmed games before and want to learn out how to deliver games across multiple platforms, or develop games faster, then Haxe Game Development Essentials is the book for you.
It starts by showing you how to set up your development environment, then running you through some Haxe language fundamentals, and finally taking you through the process of programming a game from start to finish.
You will learn how to create a side scrolling shooter game using HaxeFlixel. Next you will learn to enhance the game with new gameplay features, user interfaces, animations, sound, and configuration files to make your game expandable. Once your game is built and ready, you will learn how to deploy it to web, Android, iOS, and desktop systems.
By the end of this book, you will be confident about creating multi-platform games using Haxe, OpenFL, and HaxeFlixel in a faster and easier way.

Leseprobe

Table of Contents

Haxe Game Development Essentials

Credits

About the Author

Acknowledgements

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Getting Started

What's Haxe?

OpenFL

HaxeFlixel

Installation

Installing Haxe

OpenFL

Setting up an IDE

Installing HaxeFlixel

Setting up target platforms

Flash

Android

iOS

Desktop

Hello World

Creating a project

Running the project

Copying assets

Making changes

Summary

2. Building a New Game

The Haxe syntax

Data types and structures

Operators

Access modifiers

Variables

Functions

The for loops

Classes

Setting up a new HaxeFlixel project

Creating the new project

The anatomy of our project

Changing settings

Adding assets

Adding a background and basic UI

Making enemies

Creating the enemy class

Adding variables

Setting up the display

Creating the spawn timer

Instantiating enemies and adding interaction

Adding new imports

Adding variables

Creating instances and adding mouse events

Creating the end screen

Creating the end screen class

Adding variables

Adding the background and score text

Restarting the level

Implementing the game timer

Importing the end screen

Adding variables

Creating the level timer

Creating the timer callback function

Summary

3. Dealing with Menus and Screen Flow

Adding new assets

Changing the default state

Building the splash screen

Adding imports

Creating variables

Adding sprites

Adding instructions

Starting the animation sequence

Creating the next stage of the sequence

Finishing the sequence

Navigating back to the game

Updating the level end screen

Adding imports

Adding variables

Housekeeping

Adding the group and setting up the window

Adding scores

Adding the play again button

Showing the best score sprite

Creating the animation sequence

Creating the new game HUD

Creating the GameHUD class

Adding imports

Adding variables

Laying things out

Changing the score

Adding the new game HUD

Adding imports

Adding variables

Housekeeping

Adding the HUD and enemy group

Summary

4. Delving into Animations and Gameplay

Object pooling

Project updates

Adding new assets

Updating the project settings

Creating the explosion effects

Creating the class

Adding imports

Creating variables

Setting up Texture Packer data

Adding sprites

Creating a particle emitter

Adding everything to the group

Starting the explosion sequence

Showing the explosion bulb

Showing smoke and completing the animation

Preparing for object pooling

Making muzzle flashes

Creating the class

Adding imports

Creating variables

Adding sprites

Playing the flash

Showing the rings

Updating enemies

Adding imports

Adding variables

Adding animation

Resetting the spawn position

Updating the onSpawn function

Adding death functionality

Creating projectiles

Creating the class

Adding imports

Creating variables

Displaying the sprite and setting the velocity

Making the player character

Creating the class

Adding imports

Creating variables

Adding animation

Making the projectile pool

Creating the muzzle flash

Starting the shoot timer

Shooting projectiles

Handling player input

Building movement functions

Handling player death

Setting health on the HUD

Changing hearts

Adding everything to PlayState

Adding imports

Adding variables

Cleaning things up

Adding the scrolling backdrop

Creating and adding the player

Creating an explosion object pool

Killing enemies

Updating the score

Detecting collisions

Handling collisions between projectiles and enemies

Handling collisions between the player and enemies

Summary

5. Adding Sound

Project updates

Adding new assets

Updating the project settings

Creating sound constants

Creating the class

Creating sound ID constants

Creating volume constants

Building the sound manager class

Creating the class

Adding imports

Implementing the singleton pattern

Adding music

Creating playback functions

Calling playback functions

Adding menu sounds

Creating playback functions

Calling playback functions

Adding gameplay sounds

Creating variables

Creating functions

Calling playback functions

Summary

6. Working with Configuration Files

JSON versus XML

Project updates

Adding new assets

Understanding the JSON configuration file

A simple example

Looking at the JSON format

Building the enemy spawner

Creating the enemy spawner class

Adding imports

Adding variables

Parsing JSON data

Populating the pool

Spawning enemies

Adding movement patterns to enemies

Adding imports

Adding variables

Removing old functionality

Creating the startPattern function

Updating onSpawn and resetSpawn

Updating PlayState

Removing old functionality

Using EnemySpawner

Understanding the XML file

Looking at the file's contents

Pulling string data from XML

Building the Strings class

Handling XML data

Building the StringIDs class

Replacing strings

Updating MenuState

Updating GameHUD

Updating LevelEndScreen

Summary

7. Deploying to Multiple Platforms

Building for Flash

Deploying to the Web

Building for Windows

Building for OS X

Building for Android

Building for iOS

Xcode setup

Setting up a certificate

Setting up an App ID

Registering a device

Creating a provisioning profile

Running the game on iOS

Summary

8. What's Next?

Expanding the game

Level-based gameplay

Power-ups and collectibles

More enemies and bosses

Exploring advanced features

Gamepads

Physics

Tilemaps

Continuing on with learning resources

Haxe

OpenFl

HaxeFlixel

Community resources

Summary

Index

Haxe Game Development Essentials

Haxe Game Development Essentials

Copyright © 2015 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: November 2015

Production reference: 1241115

Published by Packt Publishing Ltd.

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Credits

Author

Jeremy McCurdy

Reviewers

Romuald Halasz

Nathan McDonald

Robin Poirier

Acquisition Editors

Harsha Bharwani

Usha Iyer

Content Development Editor

Samantha Gonsalves

Technical Editor

Edwin Moses

Copy Editor

Dipti Mankame

Project Coordinator

Sanchita Mandal

Proofreader

Safis Editing

Indexer

Hemangini Bari

Production Coordinator

Shantanu N. Zagade

Cover Work

Shantanu N. Zagade

About the Author

Jeremy McCurdy is a game developer who has been making games using ActionScript, C#, and Haxe for over four years. He has developed games targeted at iOS, Android, Windows, OS X, Flash, and HTML5. He has worked on games that have had millions of gameplay sessions, and has built games for many major North American television networks.

He is the games technical lead at REDspace, an award-winning interactive studio that has worked for some of the world's largest brands. They are located in Nova Scotia, Canada, and have been building awesome experiences for 15 years.

Acknowledgements

I would like to thank my family for constantly pushing me to reach my goals. Thanks go to my parents, Gaile Jodrey and Blaine McCurdy; sisters, Darlene and Gabrielle Therrien; grandparents, Roy and Marg Jodrey; and cousin, Tammy Lucy Prall.

I would also like to thank my college instructor, Sean Morrow, from the Nova Scotia Community College's Truro Campus. He set me on the path to being a programmer twice, taught me the fundamentals of programming, and made learning incredibly fun.

I'd also like to thank my coworkers who pushed me from being a scared little intern to a proper technical lead—Shane Kerr, Thomas Gillis, Armen Abrahamyan, Mike McGraw, Robin Poirier, and Nathan McDonald.

Lastly, I'd like to thank Mike Johnston and Wes Gould, who have given me awesome career opportunities at REDspace and made a workplace that I feel proud to be a part of.

I wouldn't be here writing this now if it weren't for all of these people. They have all made my life as a developer possible, and I honestly can't thank them enough.

About the Reviewers

Romuald Halasz began his adventure in the world of programming nearly 20 years ago. His passion for writing code was sparked by computer games. He was amazed by them and wanted to learn how they are made in order to bring his own ideas to life. It's been a wonderful experience that involved learning and great amounts of fun.

Throughout his journey, he has explored different segments of the development spectrum, such as web development, enterprise software development, and more recently, mobile development.

He has worked in different companies, from start-ups to multinationals. He has also tried his hand at freelancing. In general, he sees coding as a way of life. It is a journey of learning and giving life to projects, which start with one idea. There is also the satisfaction of people using the products that you have worked on.

Nathan McDonald is a game developer who is currently working at REDspace, where he helps build games using languages and tools such as Haxe, Flambe, and Unity.

I would like to thank Jeremy McCurdy for the opportunity to help him with this book and Robin Poirier for all the help that he's given.

Robin Poirier is a game developer from Nova Scotia, Canada. He works mainly in Haxe/Flambe and Unity3D. He has developed games that deploy for iOS, Android, Flash, and HTML5. He currently works at REDspace as part of their games division.

Specials thanks to Jeremy McCurdy for this opportunity to be part of this book and Nathan McDonald for being a good rubber duck.

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Preface

Developing games that can reach a wide audience can often be a serious challenge. A big part of the problem is figuring out how to make a game that will work on a wide range of hardware and operating systems. This is where Haxe comes in.

Over the course of this book, we'll look at getting started with Haxe and the HaxeFlixel game engine, build a side-scrolling shooter game that covers the core features you need to know, and prepare the game for deployment to multiple platforms.

After completing this book, you will have the skills you need to start producing your own cross-platform Haxe-driven games!

What this book covers

Chapter 1, Getting Started, explains setting up the Haxe and HaxeFlixel development environment and doing a quick Hello World example to ensure that everything is working.

Chapter 2, Building a New Game, looks at the fundamentals of the Haxe language and building the core foundation of our game.

Chapter 3, Dealing with Menus and Screen Flow, helps to set up our game's UI, add simple UI animations, and control the flow between screens.

Chapter 4, Delving into Animations and Gameplay, explains adding sprites and scripted animations and adding the bulk of our gameplay functionality.

Chapter 5, Adding Sound, delves into the aspects of adding music and sound effects to make our animations and gameplay truly engaging.

Chapter 6, Working with Configuration Files, talks of using JSON and XML configuration files to make our game expandable and editing the text far easier.

Chapter 7, Deploying to Multiple Platforms, shows how to take our completed game and build it to work on desktop, web, and mobile platforms.

Chapter 8, What's Next?, looks at game features to expand on and at resources to continue learning.

What you need for this book

The introductory chapter of the book will walk you through getting the tools you need to develop with. However, you will need a computer to develop with. You can develop games with Haxe on Apple OS X, Microsoft Windows, or Linux operating systems.

In order to develop a game for a particular operating system, you will need to have access to a machine with it installed to create playable builds. For example, you need to be using OS X to develop a game targeted at OS X.

For mobile platforms, you can use any operating system to develop Android applications, but you will need a Mac running OS X to develop iOS applications. You will also need an iOS device in order to develop for iOS; this can be an iPhone, iPad, or iPod Touch.

Who this book is for

This book is for game developers with some experience in programming games on one or more platforms already. If you want to leverage your game development experience on one platform to develop for multiple platforms and to get up and run quickly, this book is for you.

In addition, if you want to learn how using Haxe, OpenFL, and HaxeFlixel can make multiplatform development faster and easier, this book will show you.

Having prior experience with a language similar to Haxe, such as ActionScript or JavaScript, will help, but isn't required.

Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Open MenuState.hx and navigate inside the Create function."

A block of code is set as follows:

override public function create():Void { super.create(); }

Any command-line input or output is written as follows:

lime test flash

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "If you're using FlashDevelop, you can create a class by right-clicking on the source folder and going to Add | New Class."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.

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Chapter 1. Getting Started

In this chapter, we're going to see what Haxe is, how it will enable you to create awesome multiplatform games, and then we'll install all of the tools we'll need to develop with. After setting things up, we'll work with a quick Hello World example to make sure that everything works and we're ready to start making games!

Here's a rundown of the sections in this chapter:

What's Haxe?InstallationSetting up target platformsHello WorldSummary

What's Haxe?

Haxe is an open source programming toolkit that is composed of a language, compiler, and command-line interface. It is heavily inspired by ActionScript 3, with some tweaks here and there to add functionality. It also draws some inspiration from C#. It's so similar that at a glance, Haxe code could easily be confused for ActionScript. This doesn't mean that you have to know ActionScript to learn Haxe, but it does help. Knowing an object-oriented language, such as C# or Java, will also give you a leg up.

Haxe compiles to several different platforms, allowing you to have one codebase that will work in browsers, desktop operating systems, and on mobile devices.

In case you were wondering about the pronunciation, Haxe is pronounced Hex, though many people pronounce it Hacks.

OpenFL

OpenFL is a framework built on top of Haxe; it adds additional API functionality and provides build tools to streamline your workflow. Most of the API changes it introduces are meant to help mimic the ActionScript 3 API. For example, it adds support for Flash's Stage 3D mode, text formatting, and bitmap data.

OpenFL also uses the Lime library, which is a library that helps to ensure consistent cross-platform support so that builds for different platforms don't behave radically differently. It covers things such as cross-platform audio, rendering, and asset management.

Some of our build commands will be executed using Lime, and that's pretty much all we'll be directly using it for.

HaxeFlixel

HaxeFlixel is a game engine that's built on top of OpenFL. It was originally based on the ActionScript 3 game engine named Flixel, and has since branched off on its own. It's well documented and has a solid community, making it an ideal engine for people who want to learn how to make games with Haxe.

HaxeFlixel supports the following features:

Efficient and high-performance renderingCollision detectionParticlesTilemapsBitmap fontsPathfindingObject poolingTweeningGPU acceleration

That's just a handful of the features of the engine; it's very robust. HaxeFlixel will help us start building high-quality games much faster than doing everything from scratch.

Installation

Now that you have a good understanding of what we'll be using, let's start installing what we'll need. Haxe, OpenFL, and HaxeFlixel are all designed to be easy to set up, so this is going to be pretty straightforward.

Installing Haxe

Go to http://haxe.org/download/ and download the installer for your operating system. Run the installer; be sure to install both Haxe and Neko when given the option.

This will install the Haxe framework, which includes Haxelib, a useful tool for installing Haxe frameworks and libraries. You will typically use this to install all Haxe libraries, which will make the installation of OpenFL and HaxeFlixel incredibly straightforward.

OpenFL

To install OpenFL, open a command window (or terminal on OS X and Linux). Next, run the following commands:

haxelib install openflhaxelib -notimeout run openfl setup

These two commands will download, install, and set up the OpenFL framework and all of the libraries it needs. The notimeout flag prevents the setup from timing out before it completes. This is useful because the OpenFL setup will download quite a number of files, and it can time out if your internet connection is a little slow.

When asked if you want to install OpenFL, press Y. On Mac and Linux, you may be asked to enter your password. After this, OpenFL will be installed and you'll be good to go!

Setting up an IDE

Before installing HaxeFlixel, it's important to install a code-editing tool, because you will be prompted to choose one during the HaxeFlixel setup. Your operating system will be a factor in choosing the best tool for you.

Windows users are able to use FlashDevelop, which is a fully featured IDE that will work with Haxe out of the box. The best part of using FlashDevelop is that you can debug your games by targeting Flash and using the Flash debug player. This will allow you to put in breakpoints, see console logs, and inspect variables. You can download the latest version by going to http://flashdevelop.org. If you are using Windows, I highly recommend using it.

For Mac and Linux users, the best tool available is Sublime Text 2. It's a solid code-editing tool, though it lacks support for breakpoints, console logs, and variable inspection. You can download the latest version by going to http://sublimetext.com. You can also use Sublime Text on Windows if you prefer it.

To make Sublime Text a more effective Haxe editing tool, you should install the Haxe plugin. The easiest way to install it is using package control, which you can install using the steps located at https://packagecontrol.io/installation#st2.

After installing package control, use Ctrl + Shift + P (Windows or Linux) or cmd + Shift + P (Mac) to bring up the command palette. Start typing in package and then navigate down to Install Package. You will then see a list of available packages to install. Type in Haxe to find the package named Haxe. Install that and you're good to go!

Installing HaxeFlixel

To install HaxeFlixel, run these commands:

haxelib install flixelhaxelib install flixel-toolshaxelib run flixel-tools setup

You will then be prompted several times during the setup. Here's what you should do:

When a command appears asking if you want to set up Flixel, press Y.When asked if you would like to download flixel-demos and flixel-templates, press Y.When prompted to enter an author name, either type in your name or leave the field blank. It will automatically use that name when creating project templates.When asked to choose your default IDE, enter the number corresponding to your development tool of choice.Choose either Y or N