www.it-ebooks.info ffirs.indd iiffirs.indd ii 10/28/2011 4:23:12 PM10/28/2011 4:23:12 PM www.it-ebooks.info BEGINNING iOS GAME DEVELOPMENT INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi PART I THE TOOLS TO GET STARTED CHAPTER 1 Games on iOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 CHAPTER 2 The Xcode Programming Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 CHAPTER 3 The C Programming Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 CHAPTER 4 The Objective-C Programming Language . . . . . . . . . . . . . . . . . . . . . . . . . 95 CHAPTER 5 The Cocoa Foundation Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137 PART II GAME BUILDING BLOCKS CHAPTER 6 Drawing with UIKit and Core Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . 173 CHAPTER 7 Responding to User Interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 CHAPTER 8 Animating Your Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 CHAPTER 9 Making Noise with iOS Audio APIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 CHAPTER 10 Building a Networked Game with GameKit . . . . . . . . . . . . . . . . . . . . . . . 333 APPENDIX Answers to Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 ffirs.indd iffirs.indd i 10/28/2011 4:23:12 PM10/28/2011 4:23:12 PM www.it-ebooks.info ffirs.indd iiffirs.indd ii 10/28/2011 4:23:12 PM10/28/2011 4:23:12 PM www.it-ebooks.info BEGINNING iOS Game Development ffirs.indd iiiffirs.indd iii 10/28/2011 4:23:13 PM10/28/2011 4:23:13 PM www.it-ebooks.info ffirs.indd ivffirs.indd iv 10/28/2011 4:23:13 PM10/28/2011 4:23:13 PM www.it-ebooks.info BEGINNING iOS Game Development Patrick Alessi ffirs.indd vffirs.indd v 10/28/2011 4:23:13 PM10/28/2011 4:23:13 PM www.it-ebooks.info Beginning iOS Game Development Published by John Wiley & Sons, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2012 by Patrick Alessi Published by John Wiley & Sons, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-1-118-10732-4 ISBN: 978-1-118-22408-3 (ebk) ISBN: 978-1-118-23161-6 (ebk) ISBN: 978-1-118-26231-3 (ebk) Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions. Limit of Liability/Disclaimer of Warranty: The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifi cally disclaim all warranties, including without limitation warranties of fi tness for a particular purpose. No warranty may be created or extended by sales or pro- motional materials. The advice and strategies contained herein may not be suitable for every situation. This work is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional services. If professional assistance is required, the services of a competent professional person should be sought. Neither the pub- lisher nor the author shall be liable for damages arising herefrom. The fact that an organization or Web site is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or website may provide or recommendations it may make. Further, readers should be aware that Internet websites listed in this work may have changed or disappeared between when this work was written and when it is read. For general information on our other products and services please contact our Customer Care Department within the United States at (877) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002. Wiley publishes in a variety of print and electronic formats and by print-on-demand. Some material included with stan- dard print versions of this book may not be included in e-books or in print-on-demand. If this book refers to media such as a CD or DVD that is not included in the version you purchased, you may download this material at http://booksupport.wiley.com. For more information about Wiley products, visit www.wiley.com. Library of Congress Control Number: 2011940541 Trademarks: Wiley, the Wiley logo, Wrox, the Wrox logo, and Wrox Programmer to Programmer are trademarks or reg- istered trademarks of John Wiley & Sons, Inc. and/or its affi liates, in the United States and other countries, and may not be used without written permission. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book. ffirs.indd viffirs.indd vi 10/28/2011 4:23:18 PM10/28/2011 4:23:18 PM www.it-ebooks.info For Morgan — I hope that watching me take on and conquer a diffi cult task inspires you to do the same. ffirs.indd viiffirs.indd vii 10/28/2011 4:23:18 PM10/28/2011 4:23:18 PM www.it-ebooks.info ffirs.indd viiiffirs.indd viii 10/28/2011 4:23:18 PM10/28/2011 4:23:18 PM www.it-ebooks.info [...]... blog/2011_05_distimo-and-newzoo%C2%A0partner-on-games-data-over-5-million-iosgames-downloaded-per-day-by-63-million -ios- gamers-in-us-eu/), games are the largest cat- egory of applications on the app store A full half of all downloads of free and paid apps are games According to the National Gamers Survey in March 2011, there were more than 60 million iOS gamers in the US and Europe As you can see, there is a huge fi nancial incentive to write games... features of games on iOS ‰ Documenting and developing your idea ‰ Prototyping and preparing your game for coding ‰ Getting an overview of the game- related frameworks in iOS Since you have picked up this book and are reading this, you must be interested in writing a game for iOS Why do you want to write a game? There are some great reasons to write a game for iOS, fi rst and foremost is that writing a game. .. good game WHAT MAKES A GOOD IOS GAME? As an aspiring iOS game developer, the fi rst question that you need to ask yourself is, “What makes a good iOS game? ” In this section, I’ll try to give you some ideas that you can think about while you are designing your game Device Usage As you start to formulate your ideas on your iOS game, you need to keep several things in mind The fi rst is how people use iOS. .. reality in a game In your game, you make the rules Writing games for iOS can be particularly fun because of the amazing capabilities of the device You can include using a GPS, camera, accelerometer, and even a gyroscope in your game Writing games for iOS can also be fi nancially rewarding With the ubiquity of iOS devices, millions of people can play your game Moreover, since you will distribute your game in... STARTED CHAPTER 1: GAMES ON IOS 3 What Makes a Good iOS Game? Device Usage Use Unique Features of iOS Make Your Game Fun Graphics and Design 4 4 4 5 6 Developing Your Idea 6 Documenting Your Game Prototyping Your Game Preparing to Code 6 7 8 Game- Related Frameworks 9 Cocoa Drawing: UIKit and Core Graphics User Interaction: Cocoa Touch Animation: Core Animation Sound: Core Audio Game Kit Summary 9 11... design of a successful game Use Unique Features of iOS Some other factors that you should consider when designing your iOS game is how a player will control the game and how you can take advantage of the advanced features of iOS devices The most successful games on iOS have very simple control schemes There are no physical buttons available on an iOS device Therefore, designing a game that needs a controller... writing for the Mac or iOS That was a major factor in my decision to write this book Every other book that I have seen on iOS game development assumes a foundation in basic iOS programming I have not done that I start from the beginning and guide you through the whole process of writing games for iOS from start to finish By the end of this book, you will have written several games and you will have... consideration while you are designing your game should be to make the game fun If the game is not fun, no one will want to play it Keep in mind that you will be playing the game very often as you are developing it If the game is not fun, you will not enjoy the development process and this will show through in the game Think about what makes games fun and apply those things to your game Different people have different... CHAPTER 1 GAMES ON IOS ‰ Traffic Rush ‰ Tap Tap Revenge Classic ‰ AppBox Pro Alarm ‰ Flight Control Notice that nine of the ten best-selling applications of all time for the iOS platform are games Therefore, your choice to start investing your valuable time as an iOS game developer is a good one But, before worrying about making millions in the App Store, you need to think about not just making any iOS game, ... to the way that they play games Take another look at the top iOS applications You could categorize each of the games as a casual game There are no 100-hour RPGs or fi rst person shooters on the list All of the games on the list are easy to pick up for fi rst-time gamers Additionally, all of these games let you get in and out quickly in short bursts Think about how people use games or other applications . PM www.it-ebooks.info BEGINNING iOS Game Development Patrick Alessi ffirs.indd vffirs.indd v 10/28/2011 4:23:13 PM10/28/2011 4:23:13 PM www.it-ebooks.info Beginning iOS Game. TO GET STARTED CHAPTER 1: GAMES ON IOS 3 What Makes a Good iOS Game? 4 Device Usage 4 Use Unique Features of iOS 4 Make Your Game Fun 5 Graphics and Design