Distributed Gaming using J2ME

By Rekha Vaddepalli

Agenda

IntroductionRequirementsTechnologies UsedDesign and ImplementationExperiments and ResultsConclusion

Introduction

Mobile devices usage is increasingrapidlyIn tandem, mobile games developmentis increasingDevelopment platforms

J2ME, C++ etc

RequirementsPurpose

To develop a distributed, multi-player gamewith a central server to simulate certaineconomic scenarios.Sample scenarios tested

Making a certain product tougher to produce and alsomaking it costlier than the other productsChoosing to produce a certain product benefits theplayerSimulation of real world issues

It can also be viewed as a regular strategygame by the people more interested instrategy games

Requirements (contd..)Scope

To implement Acquire game for J2ME-enabledPDAs using J2ME, Servlets, JDBC and MySQL

Acquire game borrows ideas from oldcomputer game “Mule”Game world consists of number of plot areascomprising of nine sub plots

Each plot has 3 propertiesMine ValueFarm ValueEnergy Value

Requirements (contd..)

Game consists of 4 stagesSelection of plot areasConfiguration of plot areasProductionAuction

RulesIf the player satisfies critical resources limits of all typeof products, can go for another round of selectionThe player must finish the auction that he started in theprevious round to start the auction in the next round

J2ME (Java 2 Micro Edition)

Two key componentsConfiguration

JVM for each kind of deviceDefines the Java Runtime Environment and coreclasses that operate on each deviceEx: CLDC & CDC

ProfileConsists of Java classes that enable implementationof features for a particular device or group of devicesEx: MIDP, Foundation Profile etc.

J2ME Concepts (contd..)

User Interface ClassesUsed Form class for all the screensUsed CustomItem class for game worldrepresentation

Persistent StorageUsed for storing intermediate values inConfiguration stage

Generic Connection FrameworkUsed for communicating with the server

MIDP Applications (MIDlets)Introduction of Verification step afterCompilation

Divided into two stepsPre-verification is done off the deviceSimple second verification step on the device

DeploymentUsing MIDlet suites

JAR fileManifest File (included in JAR)Application Descriptor (outside JAR)

Other technologies used

Java ServletsJava Database Connectivity (JDBC)MySQL Database

Operating Environment

Application OperatingEnvironment

Game Client J2ME Wireless Toolkit,Windows CE/ME

Game Server Java 1.4.1 or higherinstalled on Windows

Database Oracle 9i / MySQL

Design and ImplementationSystem Architecture

Server

J2ME devices

Server

Database

HTTP

JDBC

Server Design

Register & LoginCreate New Game WorldUpdate

On SelectionOn ConfigurationOn Role DeclarationOn TradeOn Transfer Of UnitsOn Log off

Get Score

Selection

Configuration& Production

Declare Roles

Rule 1

Rule 1: Produce >= critical limit (for each type of the product)Rule 2: Finished auction started in the previous round

Auction

Trade

Rule 2

Game Design

Logging in

Selection Phase

Configuration/Production

Auction Stage

Local Auctions

Game 1, 2 & 3 canbe seen as 3different localauctionsA is involved in bothGame 1 & 2So, A can transferunits between thetwo local auctions

Game OneGame Two

Game Three

A BA

C

D E

F

ExperimentsRealization of local auctions

Game One

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Before & After Transfer Of Units

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M F E R S M F E R S

Game Two

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Before & After Transfer of units

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Configuration file on theServer

Helps to create different scenariosThis file contains

Several initial parametersInitial mine units, food units etc.Time slots for Selection, Configuration etc.

Expenditure FormulaeProduction FormulaeScore formula

Test Case OneDescription

Making one product tougher to producecompared to other products and that particularproduct is sold at a higher priceFor this test case, I chose mines to be thetougher to produce product.Machinery Expenditure formula is modified sothat less mines are produced.

Production = (Type_Of_Product * Appropriate_Property_Value)

MachineryExpenditure = 10 * (Sum of Property Values)

Test Case One: With 2 playersResults

Test Case One: 2 Players

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Average Mine Value

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Test Case One: With 4 playersResults

Test Case One: 4 Players

AC

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Rokda Units

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Size ofbubble :Score

Test Case TwoDescription

Just deciding to produce a particularproduct will increase the scoreFor this test case, I chose that if the playerchooses to mine, he would have a betterscore

Score = (Mine_Count * 10) + (Farm_Count *2) + (Energy_Count * 2)

Test Case Two:With 2 playersResults

Mining Count Chart

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Scores

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Test Case Two:With 4 PlayersResults

Test Case Two: 4 players

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Mining Count

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Round2

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Round4AB&C

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Test Case Three

DescriptionThe worker and land expenses are higher forproducing mines than for farming or energyproduction.

WorkerExpensesForMining=(10*(Sum Of Property Values))LandExpensesForMining=(10*(Sum Of Property Values))

WorkerExpensesForFarming=(2*(Sum Of Property Values))LandExpensesForFarming=(2*(Sum Of Property Values))

WorkerExpensesForEnergy=(3*(Sum Of Property Values))LandExpensesForEnergy=(3*(Sum Of Property Values))

Test Case Three: With 2 PlayersResults

Score Comparisons in the two rounds

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Comparison Chart

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Rounds 1 & 2

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M F E R M F E R

Test Case Three: 4 PlayersResults

Comparison Chart

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Round 1 & 2

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Comparison of Score values

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ConclusionPossible applications of this project

Economic simulationsStrategy game

Similar ApplicationsThe Economics classes are generally passive andapplications like these will help in the betterunderstanding of the Economics concepts

http://www.people.virginia.edu/~cah2k/programs.htmlhttp://www.irean.vt.edu/research_workshop_april2003/03_Goad.pdf (Wireless Interactive Training Solutions)

They claim that they had good success using PDAsin the classrooms for their experiments

Future EnhancementsBetter security features.More types of products can beintroduced to make it more realistic.Implementation of more types ofauctions that are possible in the realworld.

Questions?