Table Of ContentHTML5 Game Development
with ImpactJS
A step-by-step guide to developing your own 2D games
Davy Cielen
Arno Meysman
BIRMINGHAM - MUMBAI
HTML5 Game Development with ImpactJS
Copyright © 2013 Packt Publishing
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First published: March 2013
Production Reference: 1140313
Published by Packt Publishing Ltd.
Livery Place
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Birmingham B3 2PB, UK.
ISBN 978-1-84969-456-8
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Cover Image by Shutterstock
Credits
Authors Project Coordinator
Davy Cielen Anugya Khurana
Arno Meysman
Proofreader
Bernadette Watkins
Reviewers
Makzan
Kevin Roast Indexer
Hemangini Bari
Acquisition Editor
Robin de Jongh Production Coordinator
Arvindkumar Gupta
Lead Technical Editor
Arun Nadar Graphics
Valentina Dsilva
Technical Editors
Soumya Kanti Cover Work
Arvindkumar Gupta
Veena Pagare
Copy Editors
Alfida Paiva
Laxmi Subramanian
Ruta Waghmare
Aditya Nair
Foreword
If you are new to programming, let me congratulate you for choosing one of the best
ways to learn it.
Writing games can be way more fun and more rewarding than playing them. It will
keep you on the edge of your seat when you first make something that you can move
on the screen, when you first make something that resembles a game, when you first
make something that is fun to play, and when you first put something out on the
Internet for others to enjoy.
You will soon discover that programming is no black magic, but just a bunch of
simple concepts glued together.
If you are new to JavaScript, the syntax can be quite confusing and some of its
concepts may seem alien at first. But hidden under all that "wait, what?" moments is
a language that is actually quite powerful, elegant, and concise. Stick to the simple
stuff at the beginning, but don't be too afraid to get your feet wet. If you come
back to something you wrote a month ago, you will have discovered more explicit
and easier ways to do it. This is true for every language, but the learning curve of
JavaScript is an especially rewarding one.
If you are new to game development, you will see that it's no more difficult than
any other kind of development. Once you get the idea of a game loop in your head
and understand how objects are moved over time, everything else will suddenly
make sense.
One of the biggest revelations when I started to make games was how almost
comically fast computers are. The amount of things you can do in 16 milliseconds,
60 times per second, is truly astonishing.
At the same time, it's astonishing how easily you can end up doing huge amounts of
operations. Compare 100 objects with each other? That's 10,000 comparisons! Still, you
can do such things and much more. So don't be afraid to try things that you think may
be too slow. Your game will most likely not be bound by computation performance.
If you are new to Impact and I would think you are, since you bought this book, you
will find that it is just the aforementioned bunch of simple concepts, neatly arranged
for you.
One of Impact's most important aspects is its simplicity. I took great care to make the
API, the functionality of Impact that is exposed to you as logical, consistent, and easy
to grasp as possible. There are no callbacks anywhere; everything that's happening
is happening in the game loop and it's happening in sequence. This makes it easy to
reason about the state of your game at all times.
But this API shouldn't discourage you to dig deeper. In fact, I would like to invite
you to take a closer look at Impact's source code.
Let's be clear here. Almost every time I had a look at the source code of a large
software library or application, I felt quite lost. If I finally found the function I was
interested in, it turned out to be just a stub with three lines of code that calls the
actual implementation elsewhere, which in turn just calls five different functions
with nondescript names in some other files.
Impact is not that large a software library. It's a very concise framework, you don't
have to read through thousands of pages of code scattered over hundreds of files.
Most things are self contained and you don't have to jump around a lot to get an
understanding of what a certain function does.
No black magic involved.
Dominic Szablewski
Creator of ImpactJS
About the Authors
Davy Cielen is the co-owner of An Ostrich On Mars, a graphic design and
marketing agency with a special branch of game design, graphics, and game
development. He has a background in analytics, marketing, and mathematics.
Davy is seriously in love with game design and web technologies.
I want to thank my wife Filipa for the support she has given me.
This book has cost Arno and me a lot of time. Filipa, you have
always been there to support us and always push me to grow
as a husband and as a person.
A special thanks to my father, Nico Cielen, who passed away
recently. He has always guided me in the journey of life. He is
a great man. Jeanine, I will never forget how you have taken
care of him.
I also want to credit my family, friends, and colleagues for
their support and understanding while we developed this book.
It has consumed a lot of my time, but I could always count on
your support.
Last but not the least, I want to thank Arno for the hard work he
has put into this book and the people at Packt Publishing for the
opportunity they have given us to write this.
Arno Meysman is the co-owner of An Ostrich On Mars, a graphic design and
marketing agency with a special branch of game design, graphics, and game
development.
Arno Meysman is a specialist at customer and web analytics using statistics and
has always been very interested in game development, including graphical design.
He started using the ImpactJS engine for hobby projects when it was first released
in 2010.
I would like to give thanks to my family and friends who have
supported me all the way through the process of writing this book.
It has not always been easy to stay at home writing, while I could
be out partying and discovering new things. I want to give special
thanks to my parents, brother, and girlfriend for always being there
for me, regardless of what crazy plans I come up with and execute.
A big thank you to all the people of PacktPub involved in the process
of making this book for guiding us all the way through. Last but not
least I would like to thank my co-author Davy. Without his technical
support, writing this book would have been near impossible.
About the Reviewers
Thomas Mak, also known as Makzan, is a developer who specializes in web
development and game design. He has over 10 years of experience in building digital
products, including real-time multiplayer interaction games and iOS applications.
He is currently a founder of a game development company, 42games
(http://42games.net), where he makes game-development tutorials and online
learning resources.
He wrote two books and one screencast series for building a Flash virtual world and
making games with HTML5 and related web standards.
I would like to thank my family and my wife, Candy Wong, for
supporting all my writings.
