making cell phone games an overview ray ratelis guild software, inc

Making Cell Phone Making Cell Phone GamesGamesAn OverviewAn Overview

Ray RatelisRay RatelisGuild Software, Inc.Guild Software, Inc.

PlatformsPlatforms

BREWBREW

iPhoneiPhone

J2MEJ2ME

Java 2 Micro EditionJava 2 Micro Edition

ConfigurationConfiguration CLDC-1.0 (JSR30)CLDC-1.0 (JSR30) CLDC-1.1 (JSR139)CLDC-1.1 (JSR139)

ProfileProfile MIDP-1.0 (JSR37)MIDP-1.0 (JSR37) MIDP-2.0 (JSR118)MIDP-2.0 (JSR118)

JSR?JSR?

JSR is Java Specification Request. It is JSR is Java Specification Request. It is similar to RFC in the internet world.similar to RFC in the internet world.

http://jcp.org/en/jsrhttp://jcp.org/en/jsr

Connected Limited Device Connected Limited Device ConfigurationConfiguration

Defines a base set of APIs and VM Defines a base set of APIs and VM features that are required for the J2ME features that are required for the J2ME runtime.runtime.

Slightly limited subset of J2SE APIs. Some Slightly limited subset of J2SE APIs. Some Java features such as reflection are limited Java features such as reflection are limited or not present.or not present.

CLDC 1.0CLDC 1.0

No floating pointNo floating point

No weak referencesNo weak references

Minimum total memory requirement of Minimum total memory requirement of 160k160k

CLDC 1.1CLDC 1.1

Added floating point support and weak Added floating point support and weak referencesreferences

Minimum total memory requirement raised Minimum total memory requirement raised to 192kto 192k

Mobile Information Device ProfileMobile Information Device Profile

Defines an additional set of APIs that Defines an additional set of APIs that support a narrower category of devicessupport a narrower category of devices Networking APIs (http, https, sockets)Networking APIs (http, https, sockets) Lcdui API (Canvas, input events, rendering, Lcdui API (Canvas, input events, rendering,

images [png, jpg])images [png, jpg]) Game API (sprites, layers, tile grids, sprite Game API (sprites, layers, tile grids, sprite

collision detection)collision detection) Media API (wav, au, mp3, midi, tone Media API (wav, au, mp3, midi, tone

sequences)sequences)

MIDP 2.0 vs. 1.0MIDP 2.0 vs. 1.0

Game APIGame API

Media APIMedia API

Authentication APIAuthentication API

Optional PackagesOptional Packages

Bluetooth APIBluetooth API

SMS and SMM messaging APISMS and SMM messaging API

OthersOthers

No guarantee they exist. I don’t yet know No guarantee they exist. I don’t yet know what happens when a MIDlet tries to use what happens when a MIDlet tries to use an API that doesn’t exist on the device.an API that doesn’t exist on the device.

MIDletsMIDlets

Applications written using the MIDP profile Applications written using the MIDP profile are called MIDlets.are called MIDlets.

Defacto standard for downloadable cell Defacto standard for downloadable cell phone games written in Java.phone games written in Java.

SDKsSDKs

Java ME SDK 3.0Java ME SDK 3.0 Sample appsSample apps IDEIDE EmulatorEmulator

Java SE Dev Kit 1.6 or higherJava SE Dev Kit 1.6 or higher Java Runtime EnvironmentJava Runtime Environment

Java ME API DocumentationJava ME API Documentation http://java.sun.com/javame/reference/apis/jsr118/http://java.sun.com/javame/reference/apis/jsr118/

Available on Sun’s websiteAvailable on Sun’s website

InstallationInstallation

First install Java SE Dev KitFirst install Java SE Dev KitThen install Java ME SDKThen install Java ME SDKRun the SDK IDERun the SDK IDEAdd new Java PlatformAdd new Java Platform Tools -> Java Platform -> Add Platform…Tools -> Java Platform -> Add Platform… Select Java ME MIDP Platform EmulatorSelect Java ME MIDP Platform Emulator Then choose the Java ME Platform SDK that Then choose the Java ME Platform SDK that

was just installed. I think this sets up the was just installed. I think this sets up the emulator.emulator.

ProgrammingProgramming

Main application must subclass the MIDlet Main application must subclass the MIDlet class.class. public class HelloMIDlet extends MIDletpublic class HelloMIDlet extends MIDlet Implement startApp(), pauseApp(), Implement startApp(), pauseApp(),

destroyApp()destroyApp() Usually creates a canvas and game thread Usually creates a canvas and game thread

and listens for commandsand listens for commands

ProgrammingProgramming

Create a canvasCreate a canvas Subclass either Canvas or GameCanvas Subclass either Canvas or GameCanvas

classclass public class TheCanvas extends public class TheCanvas extends

GameCanvasGameCanvas Implement paint(), keyPressed(), Implement paint(), keyPressed(),

keyReleased()keyReleased() Must be set as the active canvas to the MIDlet Must be set as the active canvas to the MIDlet

displaydisplayDisplay.getDisplay(midlet).setCurrent(canvas)Display.getDisplay(midlet).setCurrent(canvas)

ProgrammingProgramming

Create a game threadCreate a game thread public class GameThread implements public class GameThread implements

RunnableRunnable Implement run()Implement run() This is where the main game loop can resideThis is where the main game loop can reside

Input()Input()

Process()Process()

Render()Render()

Sleep()Sleep()

ProgrammingProgramming

Optionally create a command listenerOptionally create a command listener public class cmdListener implements public class cmdListener implements

CommandListenerCommandListener Used to receive command eventsUsed to receive command events Commands are created and added to the Commands are created and added to the

CanvasCanvas CommandListener is added to the CanvasCommandListener is added to the Canvas

canvasobject.setCommandListener(cmdlistenerobjcanvasobject.setCommandListener(cmdlistenerobject)ect)

ProgrammingProgramming

Commands show up as the menu along Commands show up as the menu along the bottom of the displaythe bottom of the display exitCommand = new Command(“Exit”, exitCommand = new Command(“Exit”,

Command.EXIT, 0)Command.EXIT, 0) canvasobject.addCommand(exitCommand)canvasobject.addCommand(exitCommand)

RunRun

The J2ME SDK comes with an emulator The J2ME SDK comes with an emulator that emulates a series of different mobile that emulates a series of different mobile devicesdevices Touch phonesTouch phones Clamshell phonesClamshell phones

Much faster than an actual phoneMuch faster than an actual phone

DistributionDistribution

.JAR .JAR Java ARchiveJava ARchive Main app file, contains all code and resourcesMain app file, contains all code and resources

.JAD.JAD Java Application DescriptorJava Application Descriptor Describes what configuration and profile Describes what configuration and profile

needs to be supported by the device, the needs to be supported by the device, the name and icon to show in the App menu, name and icon to show in the App menu, vendor, version, path to .JAR, size of .JARvendor, version, path to .JAR, size of .JAR

DistributionDistribution

Put both files onto a web sitePut both files onto a web site .JAR.JAR

mime type: application/java-archivemime type: application/java-archive .JAD.JAD

mime type: text/vnd.sun.j2me.app-descriptormime type: text/vnd.sun.j2me.app-descriptor

Browse to the .JAD file using the cell Browse to the .JAD file using the cell phone’s browser and it will ask if you want phone’s browser and it will ask if you want to install itto install it

DistributionDistribution

If available, use cell phone maker’s App If available, use cell phone maker’s App Installer to install over USB or BluetoothInstaller to install over USB or Bluetooth Not every phone has this capability (mine Not every phone has this capability (mine

doesn’t as far as I can find)doesn’t as far as I can find)

Email or otherwise send the files to your Email or otherwise send the files to your cell phone (I have no idea if this works)cell phone (I have no idea if this works)

Questions?Questions?Comments?Comments?