Beginning Android 4 Games Development

685 Pages·2011·11.588 MB·English

by  Robert Green, Mario Zechner

Beginning Android 4
Games Development

■ ■ ■
Mario Zechner
Robert Green

i
Beginning Android 4 Games Development
Copyright © 2011 by Mario Zechner and Robert Green
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Dedicated to our idols, fans, families, and loved ones
Contents at a Glance
Contents .............................................................................................................. v
About the Authors ............................................................................................. xii
Acknowledgments ........................................................................................... xiii
Introduction ...................................................................................................... xiv
■Chapter 1: Android, the New Kid on the Block ................................................ 1(cid:2)
■Chapter 2: First Steps with the Android SDK ................................................. 25(cid:2)
■Chapter 3: Game Development 101 ............................................................... 53(cid:2)
■Chapter 4: Android for Game Developers .................................................... 107(cid:2)
■Chapter 5: An Android Game Development Framework .............................. 195(cid:2)
■Chapter 6: Mr. Nom Invades Android .......................................................... 239(cid:2)
■Chapter 7: OpenGL ES: A Gentle Introduction .............................................. 279(cid:2)
■Chapter 8: 2D Game Programming Tricks ................................................... 357(cid:2)
■Chapter 9: Super Jumper: A 2D OpenGL ES Game ....................................... 435(cid:2)
■Chapter 10: OpenGL ES: Going 3D ................................................................ 495(cid:2)
■Chapter 11: 3D Programming Tricks ........................................................... 533(cid:2)
■Chapter 12: Droid Invaders: The Grand Finale ............................................. 587(cid:2)
■Chapter 13: Publishing Your Game .............................................................. 635(cid:2)
■Chapter 14: What’s Next? ............................................................................ 647(cid:2)
Index ............................................................................................................... 653
iv
Contents
Contents at a Glance .......................................................................................... iv(cid:2)
About the Authors ............................................................................................. xii(cid:2)
Acknowledgments ........................................................................................... xiii(cid:2)
Introduction ...................................................................................................... xiv

■Chapter 1: Android, the New Kid on the Block ................................................ 1(cid:2)
(cid:2)
A Brief History of Android ....................................................................................................................................... 2
(cid:2)
Fragmentation ......................................................................................................................................................... 3
(cid:2)
The Role of Google .................................................................................................................................................. 4
(cid:2)
The Android Open Source Project ...................................................................................................................... 4
(cid:2)
The Android Market ........................................................................................................................................... 4
(cid:2)
Challenges, Device Seeding, and Google I/O ..................................................................................................... 5
(cid:2)
Android’s Features and Architecture ...................................................................................................................... 6
(cid:2)
The Kernel .......................................................................................................................................................... 7
(cid:2)
The Runtime and Dalvik ..................................................................................................................................... 7
(cid:2)
System Libraries ................................................................................................................................................ 8
(cid:2)
The Application Framework ............................................................................................................................... 9
(cid:2)
The Software Development Kit ............................................................................................................................. 10
(cid:2)
The Developer Community .................................................................................................................................... 11
(cid:2)
Devices, Devices, Devices! ................................................................................................................................... 12
(cid:2)
Hardware ......................................................................................................................................................... 12
(cid:2)
The Range of Devices ...................................................................................................................................... 14
(cid:2)
Compatibility Across All Devices ........................................................................................................................... 19
(cid:2)
Mobile Gaming Is Different ................................................................................................................................... 20
(cid:2)
A Gaming Machine in Every Pocket ................................................................................................................. 20
(cid:2)
Always Connected ........................................................................................................................................... 21
(cid:2)
Casual and Hardcore ........................................................................................................................................ 22
(cid:2)
Big Market, Small Developers .......................................................................................................................... 22
(cid:2)
Summary .............................................................................................................................................................. 23
■Chapter 2: First Steps with the Android SDK ................................................. 25(cid:2)
(cid:2)
Setting Up the Development Environment ............................................................................................................ 25
(cid:2)
Setting Up the JDK ........................................................................................................................................... 26
(cid:2)
Setting Up the Android SDK ............................................................................................................................. 26
v
■ CONTENTS

(cid:2)
Installing Eclipse .............................................................................................................................................. 28
(cid:2)
Installing the ADT Eclipse Plug-In .................................................................................................................... 28
(cid:2)
A Quick Tour of Eclipse .................................................................................................................................... 30
(cid:2)
Helpful Eclipse Shortcuts ................................................................................................................................. 32
(cid:2)
Hello World, Android Style .................................................................................................................................... 33
(cid:2)
Creating the Project ......................................................................................................................................... 33
(cid:2)
Exploring the Project ........................................................................................................................................ 34
(cid:2)
Writing the Application Code ........................................................................................................................... 36
(cid:2)
Running and Debugging Android Applications ...................................................................................................... 39
(cid:2)
Connecting a Device ........................................................................................................................................ 39
(cid:2)
Creating an Android Virtual Device .................................................................................................................. 39
(cid:2)
Running an Application .................................................................................................................................... 41
(cid:2)
Debugging an Application ................................................................................................................................ 44
(cid:2)
LogCat and DDMS ............................................................................................................................................ 48
(cid:2)
Using ADB ........................................................................................................................................................ 50
(cid:2)
Summary .............................................................................................................................................................. 51
■Chapter 3: Game Development 101 ............................................................... 53(cid:2)
(cid:2)
Genres: To Each One’s Taste ................................................................................................................................ 54
(cid:2)
Casual Games .................................................................................................................................................. 54
(cid:2)
Puzzle Games ................................................................................................................................................... 56
(cid:2)
Action and Arcade Games ................................................................................................................................ 58
(cid:2)
Tower-Defense Games .................................................................................................................................... 61
(cid:2)
Innovation ........................................................................................................................................................ 62
(cid:2)
Game Design: The Pen Is Mightier Than the Code ................................................................................................ 63
(cid:2)
Core Game Mechanics ..................................................................................................................................... 64
(cid:2)
A Story and an Art Style ................................................................................................................................... 66
(cid:2)
Screens and Transitions .................................................................................................................................. 67
(cid:2)
Code: The Nitty-Gritty Details ................................................................................................................................ 73
(cid:2)
Application and Window Management ............................................................................................................ 74
(cid:2)
Input ................................................................................................................................................................. 75
(cid:2)
File I/O .............................................................................................................................................................. 79
(cid:2)
Audio ................................................................................................................................................................ 79
(cid:2)
Graphics ........................................................................................................................................................... 84
(cid:2)
The Game Framework ...................................................................................................................................... 97
(cid:2)
Summary ............................................................................................................................................................ 105
■Chapter 4: Android for Game Developers .................................................... 107(cid:2)
(cid:2)
Defining an Android Application: The Manifest File ............................................................................................ 108
(cid:2)
The <manifest> Element ............................................................................................................................... 109
(cid:2)
The <application> Element ........................................................................................................................... 110
(cid:2)
The <activity> Element ................................................................................................................................. 111
(cid:2)
The <uses-permission> Element .................................................................................................................. 113
(cid:2)
The <uses-feature> Element ......................................................................................................................... 114
(cid:2)
The <uses-sdk> Element .............................................................................................................................. 116
(cid:2)
Android Game Project Setup in Ten Easy Steps ............................................................................................. 117
(cid:2)
Market Filters ................................................................................................................................................. 119
(cid:2)
Defining the Icon of Your Game ..................................................................................................................... 119
(cid:2)
Android API Basics .............................................................................................................................................. 121
vi
■ CONTENTS

(cid:2)
Creating a Test Project .................................................................................................................................. 121
(cid:2)
The Activity Life Cycle .................................................................................................................................... 125
(cid:2)
Input Device Handling .................................................................................................................................... 132
(cid:2)
File Handling .................................................................................................................................................. 152
(cid:2)
Audio Programming ....................................................................................................................................... 158
(cid:2)
Playing Sound Effects .................................................................................................................................... 159
(cid:2)
Streaming Music ............................................................................................................................................ 163
(cid:2)
Basic Graphics Programming ........................................................................................................................ 167
(cid:2)
Best Practices ..................................................................................................................................................... 192
(cid:2)
Summary ............................................................................................................................................................ 193
■Chapter 5: An Android Game Development Framework .............................. 195(cid:2)
(cid:2)
Plan of Attack ...................................................................................................................................................... 195
(cid:2)
The AndroidFileIO Class ...................................................................................................................................... 196
(cid:2)
AndroidAudio, AndroidSound, and AndroidMusic: Crash, Bang, Boom! ............................................................. 197
(cid:2)
AndroidInput and AccelerometerHandler ............................................................................................................ 202
(cid:2)
AccelerometerHandler: Which Side Is Up? .................................................................................................... 202
(cid:2)
CompassHandler ................................................................................................................................................. 204
(cid:2)
The Pool Class: Because Reuse Is Good for You! ........................................................................................... 205
(cid:2)
KeyboardHandler: Up, Up, Down, Down, Left, Right . . . ................................................................................ 207
(cid:2)
Touch Handlers .............................................................................................................................................. 211
(cid:2)
AndroidInput: The Great Coordinator ............................................................................................................. 219
(cid:2)
AndroidGraphics and AndroidPixmap: Double Rainbow ..................................................................................... 221
(cid:2)
Handling Different Screen Sizes and Resolutions .......................................................................................... 221
(cid:2)
AndroidPixmap: Pixels for the People ............................................................................................................ 226
(cid:2)
AndroidGraphics: Serving Our Drawing Needs .............................................................................................. 227
(cid:2)
AndroidFastRenderView: Loop, Stretch, Loop, Stretch .................................................................................. 231
(cid:2)
AndroidGame: Tying Everything Together ........................................................................................................... 234
(cid:2)
Summary ............................................................................................................................................................ 238
■Chapter 6: Mr. Nom Invades Android .......................................................... 239(cid:2)
(cid:2)
Creating the Assets ............................................................................................................................................. 239
(cid:2)
Setting Up the Project ......................................................................................................................................... 241
(cid:2)
MrNomGame: The Main Activity ......................................................................................................................... 242
(cid:2)
Assets: A Convenient Asset Store .................................................................................................................. 242
(cid:2)
Settings: Keeping Track of User Choices and High Scores ............................................................................ 243
(cid:2)
LoadingScreen: Fetching the Assets from Disk ............................................................................................. 246
(cid:2)
The Main Menu Screen ....................................................................................................................................... 247
(cid:2)
The HelpScreen Class(es) ................................................................................................................................... 251
(cid:2)
The High-Scores Screen ..................................................................................................................................... 253
(cid:2)
Rendering Numbers: An Excursion ................................................................................................................ 253
(cid:2)
Implementing the Screen ............................................................................................................................... 255
(cid:2)
Abstracting… ..................................................................................................................................................... 257
(cid:2)
Abstracting the World of Mr. Nom: Model, View, Controller .......................................................................... 258
(cid:2)
The GameScreen Class .................................................................................................................................. 270
(cid:2)
Summary ............................................................................................................................................................ 277
■Chapter 7: OpenGL ES: A Gentle Introduction .............................................. 279(cid:2)
(cid:2)
What is OpenGL ES and Why Should I Care? ...................................................................................................... 279
(cid:2)
The Programming Model: An Analogy ............................................................................................................ 280
vii
■ CONTENTS

(cid:2)
Projections ..................................................................................................................................................... 282
(cid:2)
Normalized Device Space and the Viewport .................................................................................................. 284
(cid:2)
Matrices ......................................................................................................................................................... 284
(cid:2)
The Rendering Pipeline .................................................................................................................................. 285
(cid:2)
Before We Begin ................................................................................................................................................. 286
(cid:2)
GLSurfaceView: Making Things Easy Since 2008 ............................................................................................... 287
(cid:2)
GLGame: Implementing the Game Interface ....................................................................................................... 290
(cid:2)
Look Mom, I Got a Red Triangle! ......................................................................................................................... 297
(cid:2)
Defining the Viewport .................................................................................................................................... 298
(cid:2)
Defining the Projection Matrix ....................................................................................................................... 298
(cid:2)
Specifying Triangles ...................................................................................................................................... 302
(cid:2)
Putting It Together ......................................................................................................................................... 306
(cid:2)
Specifying Per Vertex Color ................................................................................................................................ 309
(cid:2)
Texture Mapping: Wallpapering Made Easy ........................................................................................................ 313
(cid:2)
Texture Coordinates ....................................................................................................................................... 313
(cid:2)
Uploading Bitmaps ......................................................................................................................................... 315
(cid:2)
Texture Filtering ............................................................................................................................................. 316
(cid:2)
Disposing of Textures .................................................................................................................................... 317
(cid:2)
A Helpful Snippet ........................................................................................................................................... 318
(cid:2)
Enabling Texturing ......................................................................................................................................... 318
(cid:2)
Putting It Together ......................................................................................................................................... 318
(cid:2)
A Texture Class .............................................................................................................................................. 321
(cid:2)
Indexed Vertices: Because Re-use is Good for You ............................................................................................ 323
(cid:2)
Putting It Together ......................................................................................................................................... 324
(cid:2)
A Vertices Class ............................................................................................................................................. 326
(cid:2)
Alpha Blending: I Can See Through You .............................................................................................................. 329
(cid:2)
More Primitives: Points, Lines, Strips, and Fans ................................................................................................ 333
(cid:2)
2D Transformations: Fun with the Model-View Matrix ....................................................................................... 334
(cid:2)
World and Model Space ................................................................................................................................. 334
(cid:2)
Matrices Again ............................................................................................................................................... 335
(cid:2)
An Initial Example Using Translation ............................................................................................................. 336
(cid:2)
More Transformations ................................................................................................................................... 341
(cid:2)
Optimizing for Performance ................................................................................................................................ 345
(cid:2)
Measuring Frame Rate. .................................................................................................................................. 345
(cid:2)
The Curious Case of the Hero on Android 1.5 ................................................................................................ 347
(cid:2)
What’s Making My OpenGL ES Rendering So Slow? ...................................................................................... 347
(cid:2)
Removing Unnecessary State Changes ......................................................................................................... 349
(cid:2)
Reducing Texture Size Means Fewer Pixels to be Fetched ........................................................................... 351
(cid:2)
Reducing Calls to OpenGL ES/JNI Methods ................................................................................................... 352
(cid:2)
The Concept of Binding Vertices .................................................................................................................... 352
(cid:2)
In Closing ....................................................................................................................................................... 356
(cid:2)
Summary ............................................................................................................................................................ 356
■Chapter 8: 2D Game Programming Tricks ................................................... 357(cid:2)
(cid:2)
Before We Begin ................................................................................................................................................. 357
(cid:2)
In the Beginning . . . There Was the Vector ......................................................................................................... 358
(cid:2)
Working with Vectors ..................................................................................................................................... 359
(cid:2)
A Little Trigonometry ..................................................................................................................................... 361
(cid:2)
Implementing a Vector Class ......................................................................................................................... 363
viii
■ CONTENTS

(cid:2)
A Simple Usage Example ............................................................................................................................... 366
(cid:2)
A Little Physics in 2D .......................................................................................................................................... 371
(cid:2)
Newton and Euler, Best Friends Forever ....................................................................................................... 371
(cid:2)
Force and Mass ............................................................................................................................................. 372
(cid:2)
Playing Around, Theoretically ........................................................................................................................ 373
(cid:2)
Playing Around, Practically ............................................................................................................................ 374
(cid:2)
Collision Detection and Object Representation in 2D .......................................................................................... 378
(cid:2)
Bounding Shapes ........................................................................................................................................... 379
(cid:2)
Constructing Bounding Shapes ...................................................................................................................... 381
(cid:2)
Game Object Attributes .................................................................................................................................. 383
(cid:2)
Broad-Phase and Narrow-Phase Collision Detection ..................................................................................... 384
(cid:2)
An Elaborate Example .................................................................................................................................... 391
(cid:2)
A Camera in 2D ................................................................................................................................................... 404
(cid:2)
The Camera2D Class ...................................................................................................................................... 407
(cid:2)
An Example .................................................................................................................................................... 409
(cid:2)
Texture Atlas: Because Sharing Is Caring ........................................................................................................... 410
(cid:2)
An Example .................................................................................................................................................... 412
(cid:2)
Texture Regions, Sprites, and Batches: Hiding OpenGL ES ................................................................................ 416
(cid:2)
The TextureRegion Class ............................................................................................................................... 417
(cid:2)
The SpriteBatcher Class ................................................................................................................................ 418
(cid:2)
Sprite Animation ................................................................................................................................................. 427
(cid:2)
The Animation Class ...................................................................................................................................... 428
(cid:2)
An Example .................................................................................................................................................... 429
(cid:2)
Summary ............................................................................................................................................................ 433
■Chapter 9: Super Jumper: A 2D OpenGL ES Game ....................................... 435(cid:2)
(cid:2)
Core Game Mechanics ........................................................................................................................................ 435
(cid:2)
A Backstory and Art Style ................................................................................................................................... 436
(cid:2)
Screens and Transitions ..................................................................................................................................... 437
(cid:2)
Defining the Game World .................................................................................................................................... 438
(cid:2)
Creating the Assets ............................................................................................................................................. 441
(cid:2)
The UI Elements ............................................................................................................................................. 441
(cid:2)
Handling Text with Bitmap Fonts ................................................................................................................... 443
(cid:2)
The Game Elements ....................................................................................................................................... 445
(cid:2)
Texture Atlas to the Rescue ........................................................................................................................... 447
(cid:2)
Music and Sound ........................................................................................................................................... 448
(cid:2)
Implementing Super Jumper .............................................................................................................................. 449
(cid:2)
The Assets Class ............................................................................................................................................ 450
(cid:2)
The Settings Class ......................................................................................................................................... 453
(cid:2)
The Main Activity ........................................................................................................................................... 454
(cid:2)
The Font Class ............................................................................................................................................... 456
(cid:2)
GLScreen ........................................................................................................................................................ 457
(cid:2)
The Main Menu Screen .................................................................................................................................. 458
(cid:2)
The Help Screens ........................................................................................................................................... 461
(cid:2)
The High-Scores Screen ................................................................................................................................ 463
(cid:2)
The Simulation Classes .................................................................................................................................. 466
(cid:2)
The Game Screen ........................................................................................................................................... 481
(cid:2)
The WorldRenderer Class .............................................................................................................................. 489

ix