Tài liệu Game Programming for Teens, Seconnd Edition P1 docx

Game Programming for Teens, Second Edition Maneesh Sethi Publisher and General Manager, Thomson Course Technology PTR: Stacy L. Hiquet Associate Director of Marketing: Sarah O’Donnell Manager of Editorial Services: Heather Talbot Marketing Manager: Heather Hurley Senior Acquisitions Editor: Emi Smith Senior Editor: Mark Garvey Marketing Coordinator: Jordan Casey Project Editor: Jenny Davidson Technical Reviewer: Jonathan Harbour Thomson Course Technology PTR Editorial Services Coordinator: Elizabeth Furbish Copyeditor: Kezia Endsley Interior Layout Tech: Jill Flores Cover Designer: Mike Tanamachi CD-ROM Producer: Brandon Penticuff Indexer: Sharon Shock Proofreader: Sara Gullion © 2005 by Thomson Course Technology PTR. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system without written permis- sion from Thomson Course Technology PTR, except for the inclusion of brief quotations in a review. The Premier Press and Thomson Course Technology PTR logo and related trade dress are trademarks of Thomson Course Technology and may not be used without written permission. BlitzPlus, Blitz3D, BlitzBasic2D, and BlitzMax are trademarks of Blitz Research, Ltd. Paint Shop Pro is a registered trademark of Corel Corpora- tion. MilkShape 3D is a registered trademark of ChumbaLum sOft. CoolEdit Pro is a registered trademark of Syntrillium Software Corporation. All other trademarks are the property of their respective owners. Important: Thomson Course Technology PTR cannot provide software support. Please contact the appropriate software manufacturer’s techni- cal support line or Web site for assistance. Thomson Course Technology PTR and the author have attempted through- out this book to distinguish proprietary trademarks from descriptive terms by following the capitalization style used by the manufacturer. Information contained in this book has been obtained by Thomson Course Technology PTR from sources believed to be reliable. However, because of the possibility of human or mechanical error by our sources, Thomson Course Technology PTR, or others, the Publisher does not guarantee the accuracy, adequacy, or completeness of any information and is not responsible for any errors or omissions or the results obtained from use of such information. Readers should be particularly aware of the fact that the Internet is an ever-changing entity. Some facts may have changed since this book went to press. Educational facilities, companies, and organizations interested in multi- ple copies or licensing of this book should contact the publisher for quantity discount information. Training manuals, CD-ROMs, and por- tions of this book are also available individually or can be tailored for specific needs. ISBN: 1-59200-834-8 Library of Congress Catalog Card Number: 2005923913 Printed in Canada 05 06 07 08 09 WC 10 9 8 7 6 5 4 3 2 1 Thomson Course Technology PTR, a division of Thomson Course Technology 25 Thomson Place Boston, MA 02210 http://www.courseptr.com For my parents, Neelam and Prabhjot J eez, there are so many people to thank. This feels like I’m accepting an Oscar™: I’m afraid the band will start playing and usher me off the stage. Anyway, first of all thank you André LaMothe for giving me a chance and taking me out to lunch. I will get you back for that one day. Thank you everyone at Premier Press: my production editor Jenny Davidson, my copy editor, Kezia Endsley, my acquisitions editor, Emi Smith, and my CD editor, Brandon Penticuff. Thanks go out to Adam Hepworth, who spent a lot of his “busy” day helping read my text and correcting a lot of errors. To all of my brothers and sisters, Rachi, who offered her help even though she was across an ocean, Nagina, whose love and support (and numerous phone calls) helped carry me through, and Ramit, who gave me a person to look up to and who helped me through the thick and thin (as well as giving me the chance to use “abeyance” in a sentence). Thanks for being here and giving me support when I needed it. To my mom and dad: I couldn’t have done this without you. I love you so much. Finally, thanks to Edgar L. Ibarra (Feo) for his artwork and Thomas Stenbäck for his work on the CD’s music. Also, to Ari Feldman, for allowing me to use his sprite library on the CD. Also, for contributing a demo program to the book, thanks to Jason Brasier and Edgar Ibarra for Rockfall and Marcus “Eikon” Smith for Galaxiga. And to everyone whose name I forgot, you know who you are. Thanks! IV Acknowledgments M ANEESH S ETHI is a high school student in California who will be enrolled at Stanford University in 2006. Maneesh has worked with Web design and development since he was in fifth grade and was the founder and head designer of Standard Design, a Web site design company. Maneesh has taught game programming on TechTV’s Call for Help and at game programming conferences such as the XGDX. He is the author of Game Programming for Teens (First Edition) and Web Design for Teens, both published by Course PTR, and How to Succeed as a Lazy Student. Besides game programming, Maneesh enjoys playing games (of course), sports such as tennis and basketball, and of course, sleep. Learn more about Maneesh, as well as his award-winning T-shirts and iPod sock case at www.maneeshsethi.com. V About the Author VI Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xi Part I: The Basics of BASIC . . . . . . . . . . . . . . . . . . .1 Chapter 1 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 A Brief History of BASIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Installing BlitzPlus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Windows and Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Toolbars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 The First Game: KONG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Compiling the Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Chapter 2 Getting to Know BASIC . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Hello, World! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Declaring Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Using Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Conditionals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Truth and Falsehood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 If .Then . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Contents VII If .Then…Else . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Select…Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Logical Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 The NOT Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 The Goto Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 A Text-Based Guessing Game . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Chapter 3 Loops, Functions, Arrays, and Types . . . . . . . . . . . . . . . . . .41 Understanding Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 For…Next . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 While…Wend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 Repeat…Until . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 Understanding Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 Scope Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 When to Use Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57 Understanding Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 Multi-Dimensional Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64 Using Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67 Coordinate Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75 For…Each…Next . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77 Putting It All Together: Textanoid! . . . . . . . . . . . . . . . . . . . . . . . . . .79 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93 Chapter 4 The Style Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 Developing Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 White Space and Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . .96 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97 Pre-Program Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99 Main Program Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 Function Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 Function and Variable Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101 Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101 Naming Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103 ContentsVIII Part II: Getting Graphical . . . . . . . . . . . . . . . . . .105 Chapter 5 Beginning Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107 Creating the Graphics Window . . . . . . . . . . . . . . . . . . . . . . . . . . . .107 Width and Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108 Color Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109 [Mode] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110 Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114 LoadImage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114 DrawImage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116 CreateImage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118 MaskImage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122 Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125 RGB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126 Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128 Cls and ClsColor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131 Chapter 6 Page Flipping and Pixel Plotting . . . . . . . . . . . . . . . . . . . .133 Page Flipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133 Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136 SetBuffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137 CreateImage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143 Locking and Unlocking Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . .156 Lock/Unlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156 ReadPixel()/ReadPixelFast() . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 WritePixel/WritePixelFast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161 Using Buffers: A Paint Program . . . . . . . . . . . . . . . . . . . . . . . . . . . .166 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .168 Main Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .170 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .172 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180 Contents IX Chapter 7 Basic Image Programming . . . . . . . . . . . . . . . . . . . . . . . . .181 Transformations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181 Translating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181 Scaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186 Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209 Parallaxing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217 TileBlock and TileImage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .218 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .225 Chapter 8 Animation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227 Using Bitmaps in Animation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227 Making Bitmaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .234 Displaying Movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .247 Chapter 9 Collision Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .249 Basic Collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .249 Bounding Circles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .253 Distance between Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .253 Radii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .255 Bounding Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .260 Pixel-Imperfect Collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .268 Pixel-Perfect Collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .272 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .274 Part III: Completing the Puzzle . . . . . . . . . . . . . .275 Chapter 10 Handling Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .277 Handling the Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .277 KeyDown() . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .278 KeyHit() . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .285 Mapping the Mouse to the Screen . . . . . . . . . . . . . . . . . . . . . . . . .294 Displaying the Mouse Cursor . . . . . . . . . . . . . . . . . . . . . . . . . . .295 What Was That? Handling Mouse Key Presses . . . . . . . . . . . . .298 The Middle Mouse Wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . .306 Handling Joystick Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .310 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .312 [...]... flavors of programming This book teaches game programming Game programming is very different from the other types of programming When you turn on your computer, you often see static programs—programs that sit there and wait for you to do something Not with games Games are running constantly, and they don’t need the player to do anything to keep it running Of course, does this mean that game programming. .. for help whenever necessary I use some rudimentary algebra, but those instances are few and far between, and should be easy to comprehend You don’t need to have any knowledge of other programming languages Not that it won’t help if you do, of course If you do know any other languages, you can learn from this book as well But, Game Programming for Teens, Second Edition teaches the language of game programming. .. amazing world of game programming! This book will show you the ins and outs of video games and teach you to develop your own Game programming is a huge topic, however, and we are going to hurry through the boring material in order to get to the fun stuff In other words, let's start right away! The easiest language for learning programming (at least in my opinion) is BASIC BASIC stands for Beginner's... along with the ability to actually implement games If you are the parent of a child who wants to learn programming, this book is the way to go General programming is a long and boring subject, but game programming allows your child to create things that are fun Help your child with programming while he or she reads this book, as well Not only will you both learn programming, but who knows, it may strengthen... 384 Introduction H ey, reader Thanks for buying my book I am really thankful for it What is programming? Programming, according to Dictionary.com, is “a set of coded instructions that enables a machine, especially a computer, to perform a desired sequence of operations.” In other words, programming allows you to make your computer do whatever you want it to do Programming is used in everything related... learn about programming I began programming in 1999 in C and Introduction C++ Two years ago I discovered BlitzPlus and I have studied it ever since BlitzPlus seems to be the easiest way for any novice to begin writing games, and I want to help the reader progress as fast as possible The Web site for this book is located on www.maneeshsethi.com, and you can e-mail me with any questions (before or after... reader all about graphics within games There is such information as varying colors, loading and displaying images, making scrolling backgrounds, and things like that Part III examines other related parts to game programming The reader can learn how to use keyboard input, sounds, and music, and take into account artificial intelligence This part also creates the final game that the book has been leading... contains all the appendixes for the book You will find all of the scan codes (for handling input), a list of Web sites to further your knowledge in the field, and what is on the CD Who Are You? I suppose you can answer this question better than I, but let me tell you what I am looking for in a reader First of all, I am guessing that you are either a teenager who is interested in game programming or a parent... bit tougher than other styles of programming? Yes and no Although game programming can be difficult at times, this book strives to turn the difficult into second nature We use a language of programming called BASIC, which, as you can probably guess, is pretty darn basic What’s in the Book? This book is meant to be a guide to teach any beginner how to design and develop games Inside the book you will... the game If KeyHit(PAUSEKEY) ;make screen blank Cls Text 400,300,"Press 'P' to Unpause Game" Flip ;wait for player to unpause While Not KeyHit(PAUSEKEY) Wend EndIf End Function This function determines what keys the user pressed, if any If it doesn’t make sense to you, try reading the following pseudocode: The First Game: KONG What Is Pseudocode? Big word, huh? Pseudocode is a very helpful device in game . has taught game programming on TechTV’s Call for Help and at game programming conferences such as the XGDX. He is the author of Game Programming for Teens. well. But, Game Programming for Teens, Second Edition teaches the language of game programming along with the ability to actually implement games. If you