Computer Games

1ComputerGamesFrederickW.B.LiE-Mail:[e-mail]ience,UniversityofDurham,UnitedKingdomI.INTRODUCTIONComputer(andvideo)gamesgainsignificantinterestsinrecentyears.Particularly,inUS,totalgamesalesfor2005wereover10.5billionUSdollars,whichmakesanimprovementof6%overthegamesalesin2004.Demographically,69%ofAmericanheadsofhouseholdsplaycomputerandvideogames.WhileinUK,whichownstheworld’sthirdlargestcomputergamemarket,82%of9-to19-year-oldyoungstersownagameconsole.Inthisarticle,wearegoingtodiscusstheexistingtechnologiesandthedesignissuesofcomputergames.Ascomputerandvideogamesarecloselyrelatedandtechnologicallycomparablewitheachother,withoutlossofgenerality,ourdiscussionwillusethetermcomputergametocoverbothofthem.Acomputergameisaninteractiveentertainmentrunningoncomputers,gameconsolesorsomeelectronicdevices,suchasmobilephonesandPDAs.Typically,acomputergameacceptsinputfromgameplayersthroughkeyboard,mouse,joystickorvarioustypesofgamecontrollerstolettheplayerscontrolandinteractwithgameobjects.Ontheotherhand,acomputergameoffersgameplayersdifferentformsoffeedbacks,includingvisual,audioandtactile,whicharerevealedthroughcomputer/TVmonitor,speakerandforce-feedbackgamecontrollers,respectively.Technically,developingacomputergameisverychallengingasitinvolvesnotonlytremendousartworkfurnishingsfromanimatorsorartists,butmorecritically,itdemandsthehardcoresupportsfromdifferentdisciplinesofcomputersciencetoaddressvarioustechnicalissues.Inthisarticle,wewilltakealookofthedevelopmentincomputergames.Inparticular,wewilldiscussthetechnicalissuesingamedevelopment.Therestofthearticlewillbeorganizedasfollows.SectionIIpresentsabriefhistoryofcomputergames.SectionIIIelaboratesthedevelopmentof2Dand3Dgames,multiplayeronlinegamesandthehandheldandmobilegames.SectionIVshowsthedetailsofthecriticalelementsinvolvinggamedevelopment.SectionVelaboratesthedetailsindevelopingagameengine.SectionVIdiscussesthemoderngamedesignissues.SectionVIIconcludesthispaperanddepictsthefuturetrendofcomputergames.II.GAMEHISTORYComputergamehasalonghistory,inwhichwecantracebackitsrootfrom1947,whenThomasTGoldsmithJrandEstleRayManndesignedthefirstgameforplayingonacathoderaytubeinUS.Here,wearenotintendedtoelaboratethefullcomputergamehistory.Instead,wefocusonthetechnologicalevolutionofcomputergameandtechnicalissuesarisenduringthechange.During1960sto1970s,gamesdevelopedweresimple,primitiveandmainlyintwo-dimension(2D).Manygames,inparticularofdifferenttypes,weredeveloped.TwoofthemostunforgettableexamplesareSpaceInvadersandPac-Man.Inaddition,handheldgamedeviceswerealsodeveloped,despitemostofthemarehardcodedtorunonlyasinglegame.Forgameplaying,gameplayersused2simplebuttoncontrollers,keyboardsorjoystickstocontroltheirgamecharacters.Themainformsoffeedbackwereofferedthroughscreendisplayswithlimitedcolorandresolutionaswellassimplesoundoutputs.In1980s,therewasamajorgrowthincomputergametechnologies.Forhardware,avarietyofpersonalcomputersandgameconsolesweredeveloped.Forsoftware,three-dimensional(3D)gamesandnetworkgameswerefirstdeveloped.Inaddition,differentformsofinputandoutputdevicesweredeveloped.Theseincludedcolormonitors,soundcardsandvarioustypesofgamepads.Theyoffergameplayersbettergamefeedbacksandgreaterflexibilityincontrollinggamecharacters.In1990s,gamesdevelopedplantedtheseedsoftoday’sgamedevelopment.Manyclassicgametypes,includingfirst-personshooters(FPS),real-timestrategy(RTS),dailylifesimulatorsandgraphicalmultiplayergames,weredevelopedduringthisperiod.Also,therewasatrendfordeveloping3Dgames.Nowadays,manynewgamesaredevelopedbasedontheseclassicgames.Themajordifferenceofthenewgamesfromtheclassiconesisthatthenewgamesaremainlyin3D.Hence,hardwaregraphicsacceleratorswereurgedtodeveloptosupportreal-timerenderingof3Dgamecontent.Totaketheadvantagethathumanvisualsensehasadominateinfluenceofagameplayertodeterminewhetheragameisgoodornot,gamecompaniesputtheirveryfirstpriorityinenhancingthegraphicsoutputfortheirgames.Theyputadvancedgraphicscontent,suchashighdetailed3Dmodels,textureimagesandvariousspecialeffects,intothegames.Besides,multimediaelements,suchasvideosandsongs,arealsousedtoenrichthegamecontent.However,sucharrangementincreasesthecomplexityofthehardwarerequirementofrunningcomputergames.Italsodemandsthedevelopmentofefficientalgorithmstomanagesuchavarietyofgamecontent.Tooptimizeboththeman-powerandtimespentingamedevelopment,gamedevelopersbegintomakeuseofready-madegameengines(PleaserefertosectionV),whichcomprisemanyusefultoolstosupportgeneralgamefunctions,tobuildtheirgames.Whenwegothroughthehistoryofcomputergames,wenotethatduringtheearlystage,gamesweremainlysimpleandsmall.Theycouldbegenerallyhandledbysimplecomputationandgraphicsprocessingpower.Hence,therewasnotreallyanystringentrequirementputtingonthedevelopmentofthesegames.Later,whengamedevelopersturnedtheirfocusto3Dgames,workingoutbothhardwareandsoftwaresolutionsinsupportingreal-timerenderingof3Dgraphicshassubsequentlybecomeacriticalpartofgamedevelopment.Besides,gamephysicsandgameartificialintelligence(AI)also