Beginning Android 3D Game Development

482 Pages·2014·8.38 MB·English

by  Robert Chin

Companion
BOOKS FOR PROFESSIONALS BY PROFESSIONALS® eBook
Available
Beginning Android 3D Game Development is a unique, examples-driven book B
for today’s Android and game app developers who want to learn how to build e
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3D game apps that run on the latest Android 5.0 (KitKat) platform using Java and i
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OpenGL ES. After reading and using this book, you’ll be able to build your first 3D n
Android game app for smartphones and tablets. in
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This book offers an extensive 3D game app case study called Drone Grid with code
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that is modular and reusable to help you create your own games using advanced
vertex and fragment shaders. Drone Grid is somewhat similar to the best-selling
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Geometry Wars game series, utilizing a gravity grid and colorful abstract graphics and
particles. d
You’ll learn: r
• o
How to build 3D game apps using Android SDK, NDK, and OpenGL ES
• Which Android SDK and NDK APIs are most useful for 3D game i
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development
• How to get a 3D Math Review for game development
3
•
How to build 3D graphics using OpenGL ES
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How to create various motion patterns
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How to set up a game environment, including gravity grid, sounds, and
heads-up display G
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How to create the characters, including the player and its enemies or targets a
•
How to develop a rich menu system with high score table
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COMPANION eBOOK
ISBN 978-1-4302-6547-4
54999
Shelve in
Mobile Computing
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Contents at a Glance
About the Author ��������������������������������������������������������������������������������������������������������������xvii
About the Technical Reviewer �������������������������������������������������������������������������������������������xix
Acknowledgments �������������������������������������������������������������������������������������������������������������xxi
Introduction ���������������������������������������������������������������������������������������������������������������������xxiii
■ Chapter 1: Let’s Meet the Android �������������������������������������������������������������������������������������1
■ Chapter 2: Java for Android ��������������������������������������������������������������������������������������������29
■ Chapter 3: 3D Math Review ���������������������������������������������������������������������������������������������57
■ Chapter 4: 3D Graphics Using OpenGL ES 2�0 ������������������������������������������������������������������81
■ Chapter 5: Motion and Collision ������������������������������������������������������������������������������������135
■ Chapter 6: Game Environment ���������������������������������������������������������������������������������������183
■ Chapter 7: Drone Grid Case Study: Creating the Player �������������������������������������������������221
■ Chapter 8: Drone Grid Case Study: Creating the Enemies ���������������������������������������������267
■ Chapter 9: Drone Grid Case Study: The User Interface ��������������������������������������������������321
■ Chapter 10: The Final Drone Grid Game �������������������������������������������������������������������������353
■ Chapter 11: The Android Native Development Kit (NDK) �����������������������������������������������393
■ Chapter 12: Publishing and Marketing Your Final Game �����������������������������������������������419
Index ���������������������������������������������������������������������������������������������������������������������������������453
iii
Introduction
This book is meant to be a quick-start guide to developing 3D games for the Android platform using
Java and OpenGL ES 2.0. Development will utilize the Eclipse Integrated Development Environment
(IDE) with Android Development Tools (ADT) plug-ins installed. The goal is to cover key concepts and
illustrate them, using concrete hands-on examples and case studies. A single book cannot cover
every aspect of Android game development or Android software development in general. Thus, this
book is not meant as a reference guide. The following is a summary of each chapter in this book.
Chapter 1: “Let’s Meet the Android.” In this chapter, I provide an overview of
Android, an overview of the Android SDK, instructions on how to set up your
computer for Android development, and a hands-on example involving a simple
“Hello World” program for those unfamiliar with Android.
Chapter 2: “Java for Android.” In this chapter, I offer an overview of the Java
language, the basic Android Java program framework, and information on the basic
Java OpenGL ES framework.
Chapter 3: “3D Math Review.” In this chapter, 3D math, vectors, matrices, and
vector and matrix operations are discussed.
Chapter 4: “3D Graphics Using OpenGL ES 2.0.” In this chapter, I provide an
overview of OpenGL ES 2.0 on Android, 3D meshes, lighting, materials, textures,
saving persistent data, and creating a gravity grid using vertex and fragment
shaders.
Chapter 5: “Motion and Collision.” In this chapter, collision and Newtonian
mechanics are covered.
Chapter 6: “Game Environment.” In this chapter, sounds and the heads-up display
are discussed.
xxiii
xxiv Introduction

Chapter 7: “Drone Grid Case Study: Creating the Player.” In this chapter, I explain
how to create a player, including elements associated with a player within our Drone
Grid game, such as weapons, ammunition and player’s HUD.
Chapter 8: “Drone Grid Case Study: Creating the Enemies.” This chapter details
how to create the enemies in our Drone Grid game. The enemies are arena objects
and tanks. Arena objects are fairly simple in their behavior. Tanks are more complex
enemy objects that will require the use of complex artificial intelligence, which
I also cover.
Chapter 9: “Drone Grid Case Study: The User Interface.” User interfaces for our
Drone Grid game are discussed in this chapter, including the Main Menu System, the
creation of the high score table, and the high score entry menu.
Chapter 10: “The Final Drone Grid Game.” This chapter brings together everything
from previous chapters into the final Drone Grid game. A final complete working
game that integrates all the elements from previous chapters is presented. The final
game will use elements discussed previously such as menus, heads up display, and
enemy objects such as arena objects and tanks.
Chapter 11: “The Android Native Development Kit (NDK).” This chapter covers the
Android Native Development Kit and discusses the Java Native Interface (JNI)
in addition.
Chapter 12: “Publishing and Marketing Your Final Game.” This chapter discusses
how to publish and market your final Android game. It includes a list of Android
marketplaces from which you can upload your game distribution file, a list of
numerous ad networks that support Android, and a list of game sites that review
Android games.
1
Chapter
Let’s Meet the Android
Android mobile phones dominate the mobile smartphone market, surpassing even Apple’s iPhone.
There are hundreds of millions of mobile phones using the Android operating system in over
190 countries around the world. Every day, a million new users begin using their Android phones to
surf the Web, to e-mail friends, and to download apps and games. In fact, in the Google Play Store
alone, there are 1.5 billion downloads per month of Android games and applications. If you include
other web sites that offer Android games and apps for sale, such as Amazon Appstore for Android,
then the number is even higher.
In this chapter, you will learn about the Android Software Development Kit (SDK). You will learn how
to set up the Android development environment. You will also learn about the major components
of this environment, such as Eclipse. We then go through the creation and deployment of a simple
“Hello World” program for Android, to both a virtual Android emulator program and also a real
Android device.
Overview of Android
The Android operating system is a widely used operating system available on mobile phones and
tablets. It is even used on a video game console called the Ouya. Android phones range from
expensive phones that require a contract to inexpensive prepaid phones that do not require any
contract. Developing programs for the Android platform does not require any developer’s fees,
unlike Apple mobile devices, which require yearly fees in order to even be able to run your program
on their devices. A good working prepaid no-contract Android phone that can develop 3D games
using OpenGL ES 2.0 can be bought on Amazon.com for as little as $75–$100 with free shipping.
Overview of the Android SDK
This section discusses the Android SDK. Development system requirements and important individual
pieces of the SDK, such as the SDK Manager, Android Virtual Device Manager, and the actual
Android emulator will be covered.
1
2 CHAPTER 1: Let’s Meet the Android

Android Software Development Kit (SDK) Requirements
Android development can be done on a Windows PC, Mac OS machine, or a Linux machine. The exact
operating system requirements are as follows:
Operating Systems:
 Windows XP (32-bit), Vista (32- or 64-bit), or Windows 7 (32- or 64-bit)
 Mac OS X 10.5.8 or later (x86 only)
 Linux (tested on Ubuntu Linux, Lucid Lynx)
 GNU C Library (glibc) 2.7 or later is required.
 On Ubuntu Linux, version 8.04 or later is required.
 64-bit distributions must be capable of running 32-bit applications.
Developing Android programs also requires installation of the Java Development Kit. Java Development
Kit requirements are JDK 6 or later and are located at www.oracle.com/technetwork/java/javase/
downloads/index.html.
If you are using a Mac, then Java may already be installed.
The Eclipse IDE program modified with the Android Development Tools (ADT) plug-in forms the basis
for the Android development environment. The requirements for Eclipse are as follows:
 Eclipse 3.6.2 (Helios) or greater located at http://eclipse.org
 Eclipse JDT plug-in (included in most Eclipse IDE packages)
 Android Development Tools (ADT) plug-in for Eclipse located at
http://developer.android.com/tools/sdk/eclipse-adt.html
Notes Eclipse 3.5 (Galileo) is no longer supported with the latest version of ADT. For the latest information
on Android development tools, go to http://developer.android.com/tools/index.html.
Android SDK Components Overview
The different components of the Android SDK are the Eclipse program, the Android SDK Manager,
and the Android Virtual Device Manager and emulator. Let’s look at each in more detail.
Eclipse with Android Development Tools Plug-in
The actual part of the Android SDK that you will spend most of your time dealing with is a program
called Eclipse, which is customized specifically for use with Android through the ADT software
plug-in. You will enter new code, create new classes, run programs on the Android emulator and on
real devices from this program. On older, less capable computers, the emulator may run so slowly
CHAPTER 1: Let’s Meet the Android 3

that the best option would be running the program on an actual Android device. Because we are
dealing with CPU-intensive 3D games in this book, you should use an actual Android device to run
the example projects (see Figure 1-1).
Figure 1-1. Eclipse with Android Development Tools plug-ins
Android SDK Manager
The Android SDK Manager allows you to download new Android platform versions and tools through
its interface. Current tools and platform versions that are installed are also displayed. For example,
in Figure 1-2, the Android 2.2 platform has already been installed and is ready for use for development.
This means that you can compile your source code to target this platform.
4 CHAPTER 1: Let’s Meet the Android

Figure 1-2. The Android SDK Manager
Android Virtual Device
The Android SDK also supports a virtual device emulator (see Figure 1-3). In many instances, you will
be able to run your Android programs on a software emulator on your development system rather
than an actual device. However, this works best for non-graphic intensive applications. Because
this book deals with 3D games, we will not be using this software emulator but an actual Android
device. The Android Virtual Device Manager allows you to create new virtual Android devices, edit
existing Android devices, delete existing devices, and start up an existing virtual Android device.
Figure 1-3 indicates that there is a valid virtual Android device named “Android22,” which emulates
the 2.2 version of the Android operating system (API Level 8) and simulates the ARM CPU type. The
2.2 version of the Android operating system is important because it is the first version that supports
OpenGL ES 2.0, which we will be using in this book to develop our 3D graphics. OpenGL is the
graphics system that allows the programmer to create 3D graphics on the Android platform. It is
designed to be hardware-independent. That is, OpenGL graphics commands are designed to be the
same across many different hardware platforms, such as PC, Mac, Android, etc. The OpenGL 2.0
version of OpenGL is the first version of OpenGL that includes programmable vertex and fragment
shaders. OpenGL ES is a subset of regular OpenGL and contains fewer features.
CHAPTER 1: Let’s Meet the Android 5

Figure 1-3. The Android Virtual Device Manager
Figure 1-4 depicts the actual emulator after it is launched. The emulator depicted is the one for
version 2.2 of the Android operating system.