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August 2007

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REGULARS

EdsNote.........................................................................................P03

News...............................................................................................P04

SPOTLIGHT

NicklasNygren,creatorofKnytt.......................................................P05

OPINION

AReallyJuicyStory.........................................................................P08

REVIEW

NewgroundsFlashPortal................................................................P09

DESIGN

BlenderIntermediateTutorial:Converting2Dto3D........................P10

ABeginnersGuidetoMakingGames:Part3..................................P12

ABeginnersGuidetoMakingGames:Part2EXTRA.....................P14

PROJECTS

RoachToaster2:BigCity................................................................P15

TECH

CodingEtiquette:Doxygen..............................................................P16

GameCodingwithTrigonometry:Part3.........................................P19

Gooptimise!....................................................................................P22

HISTORY

TheHistoryofI-ImaginePart6:EnterthePublisher......................P25

TAIL PIECE

InCasualWeTrust..........................................................................P29

CONTENTS WHATS INSIDE

05

10

22

25

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EDS NOTE THE BIG CHIEF

Wowee,thesituationisgettingintense.Iwillconfess:thingshavebeenslowthismonth.

WithIssue16,thatis.Butatthesametime,stuffisgoingreally,reallyfastanditsgetting

prettytrickytokeepupwitheverything.Onthecommunityfront,thewinnersofComp15

havebeenannouncedandaniftyR5000goestoEvil_ToasterforhisgameCartesian

Chaos(luckybugger).Wevealsogotsomeprettycoolgamesfromtherunners-upandafullreportwillbe

presentinthenextDev.Mag.Inthemeantime,wevealsogotComp16startingup(text-basedgraphics

beingthetheme)andpeoplearescrabblingtogetsomeentriesinbeforethe28thofthismonth.

Ofcourse,IstillhaventexplainedwhyIssue16wassolongincomingout:asitsohappens,wevegotrAge

comingupattheendofthismonth.InhonourofthisannualSAtechnologyexpo(abiggieonourcalendar),

Dev.MagIssue17willcomeoutcompletewithafullvisualmakeover,amassiveamountofcontent,and

someotherexcitingoddsandendswhicharetakingupalotofourattention.Asofnow,whileImsitting

herefuriouslytappingoutmylittleeditorsspiel,theresanotherlittlewindowopenonmycomputershow-

ingthefirstdraftofthenew-lookmag,accompaniedbyatentativefirstarticle.Hopefully,theproblems

encounteredwiththiseditionwillbeforgivenonceourbumperissueseesthelightofday.

Untilthen,youhavethisoffering.Idontquiteknowhowtheteammanagesit,buteverymonthhasatleast

onepersontoddlinguptomeandpresentingsomethingawesomeforeitheraspotlightorafeature.This

month,wevesnaggedatalkwithNifflas,thecreatorofthepopular(andabsolutelyadorable)freeware

game,Knytt.Ifyoudontknowwhatitis,turntopage5andfollowthelink.Ifyoudoknowwhatitis,turn

topage5andhaveanawesometimereading.

ThatsitfornowifIblabanylonger,thismagsgoingtobedelayedevenfurther,andavidreadersare

goingtobebringingthetorchesandpitchforkstomyproverbialdoortomakesureIshutup.Staytunedfor

Dev.Mag17.Itsgoingtobeablast,andyouwontwanttomissthat.

Editor

Rodain Nandrew Joubert

EDITOR

Rodain Nandrew Joubert

DEPUTY EDITOR

Claudio Chippit de Sa

SUB EDITOR

Tarryn Azimuth van der Byl

DESIGNERS

Brandon Cyberninja Rajkumar

Geoff GeometriX Burrows

MARKETING

Bernard Mushi Mushi Boshoff

Andre Fengol Odendaal

WRITERS

Simon Tr00jg de la Rouviere

Ricky Insomniac Abell

William Cairnswm Cairns

Danny Dislekcia Day

Andre Fengol Odendaal

Heinrich Himmler RallMatt Flint Benic

Luke Coolhand Lamothe

Stefan ?rman van der Vyver

Gareth Gazza_N Wilcock

WEBSITE DESIGNER

Robbie Squid Fraser

WEBSITE

www.devmag.org.za

EMAIL

[email protected]

This magazine is a project of the

South African Game.Dev commu-

nity. Visit us at:

www.gamedotdev.co.za .

All images used in the mag are copy-

right and belong to their respectiveowners. If you try and claim other-

wise, think again. In fact, think ca-

sual.

... no, wait, scratch that.

Think sentient strawberries.

DID YOU KNOW?

Thinkthathavingajobasatesteriseasy?Think

again.Arecentchataboutthetestingprocessof

Crackdown,afree-roamurbangameconsisting

of495cityblocks,revealedsomestartlingfigures.

Oneofthesewastheamountofenvironmentbugs

thatwerereportedandsquashed:awhopping

10000.Notatypo.

DEV.MAG ISSUE 163

This months opinion columnists:

QuintonQ-man Bronkhorst

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XNA Gamefest videos released

http://creators.xna.com/Headlines/presentations/default.aspx

GameFest 2007 was an educational experience which also provided benefits for the

armchairenthusiasts.Yes,eventhosewhohaventattendedthefestivalcanstillwatch

severalcomprehensivepresentationsonthever-

satileXNAgamedevelopmenttool,thankstothe

XNACreatorsClubwebsite.Thereare7videos

viewableonline,mostofthematleasthalfanhour

longandrangingfromtopicslikeXNAGameStu-

dio forFun andProfit toprofilesof XNAworks

inprogress.Worthalookifyouhavethetime.

NVIDIA releases third GPU programming book

http://developer.nvidia.com/object/gpu-gems-3.html

NVIDIA has released its third GPU programming book,

entitled GPU Gems 3, which outlines some of the

more advanced uses of the graphics processing unit

in NVIDIA cards, even outlining uses such as physics

simulations, financial analysis and even virus detection.

Whoah! The book, which is roughly 1000 pages, also

has the latest algorithms for a menagerie of advanced

graphics effects. The price? $69.99 from Amazon.

NEWS HEADLINES

Casual games study

http://www.gamasutra.com/php-bin/

news_index.php?story=15145

Casualgamesseemtobethepopular

choice for Internet users, according to

arecentstudyconductedbyParksAs-

sociates. Gamasutra reports that the

companyhasfoundcasualgamestobe

evenmorepopular thanmajor players

such asYouTube and Myspace. Not

onlyiscasualgamingthemostpopular

pasttime,butitsgrowthinrecentyears

hasbeenimpressiveandthiswillprob-

ablymakeroomformoreaviddevelop-

ers.Timetoclamberontothebus.

Torque MMO kit free under BSD-style licence

http://www.gamedev.net/community/forums/topic.asp?topic_id=459909

WantagoodreasontobuytheTorqueGameEngineandArcaneFX?

Well,Gamedev.netreports thatthecrewfromGarageGameshave

givenfanspreciselythatwiththeoffertomaketheTorqueMMOkit

freeforbothcommercialandnon-commercialusetoanybodywho

alreadyownsTGEandArcaneFX.Accordingtothemarketblurb,

TheMMOkitrepresentsfouryearsofdevelopmentandthousandsof

hoursoflabour,andthefullPythonandTorquescriptsourceisnow

available.

DEV.MAG ISSUE 164

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Nifflas is an individual on the web whoseems to enjoy creating the cutest and

most intriguing little games. One of these

is Knytt (http://nifflas.ni2.se/), a freeware

jump n climb platformer thats notable

for being remarkably polished and eerily

engaging. We decided to have a little talk

with him about the whole game making

deal.

Tell us about how you got into game de-

velopment? What got you interested?

When did you start?

Istartedoutaround10yearsagowithKlik&

Play.Sinceitwasalongtimeago,Icantquite

remember what got me interested. Ive sim-

ply always had aninterest increating things,

nomatter ifit have beenbuildingthingswith

LEGO,composingmusic,drawingthings,orat-

temptingtocreatecomputergames.

IttookmequitealotofyearstofigureoutthatI

shouldkeepmygameprojectsatareasonable

size.IfittookSquarealargedevelopmentteam

tocreateagamelikeChronoTrigger,Ishould

haveknownbetterthanbelievingthatitwould

bepossibleformealonetocreateanRPGthat

youdneedtospendover60hourstobeat.

AfewyearsagoIrealisedthisthough,andgave

game development another go, and created

#modarchivestory- andsince thenIvebeen

releasingmygamesonamoreorlessregular

basis.Sincethenmygameshaveincreasedin

size andmorepeople havebeenhelpingme

out,butImofcoursestillnevercreatingany-

thingnearlyaslargeasthestuffIplannedinthe

past.Butreally,itsnotthesizeofthegamethat

expressmeanyway,itsthecontent.

What made you decide to create a game such

as Knytt?

Well,I wasworkingonWithin aDeepForest

SPOTLIGHT WELCOME TO THE WORLD OF KNYTT

DEV.MAG ISSUE 165

TALKING TO NICKLAS NYGRENCreator of Knytt

2,butwasntreallyinspired.IwantedWaDF2

tohavesomemini-games,soIplannedKnytttobe aWaDF2mini-game,but assoonas I

startedtocreatethefirstpartofKnytt,Igota

massive amount of inspiration to continue on

that,whileIspentlesstimeonWaDF2.Inthe

end,IabandonedWaDF2becauseofthelack

ofinspiration,andreleasedKnytt.Imstillreally

happyaboutthatdecision.Iknowalotofpeople

wouldhavepreferredmetofinishWaDF2,but

personallyIcaresomuchaboutcreatingthings

whichreallyexpressmyself-andKnyttreally

doesthat,perhapsmorethananyotherofmy

gameseverhas.

Tell us more about your upcoming game,

Knytt Stories.

Ive been working onKnyttStories since the

dayIreleasedKnytt(December2006ifI dont

rememberwrong).ItsbasedontheKnyttplat-

formengine,butfeaturesmorechallenge,pow-

er-ups, anda powerful level editor.Thistime

Im trying toencourage the players to create

theirownlevelswiththeirownuniquestories.

Itswithnodoubtmylargestcreation,anditsreleaseisjustaroundthecorner.

You created a niche on the net for your

games. Do you think every developer can

have this kind of niche?

Iseenovalueinbeingoriginaljustforthesake

ofbeingoriginalitself.Idohoweverthinkthat

mostgamesaretooalikethesedays,asifthe

developersjustseetheirgamesasentertainent

createdtomeetthedemandsoftheaudience,

rather than a form ofartistic expression. Of

course,thereareplentyofexceptions.

The music in Within A Deep Forest and Knytt

lends a great deal to the atmosphere of the

game. Have you ever considered making

music as a career?

IbettermentionfirstthatIdidntcreatemostof

themusicforWithinaDeepForest,Ionlycre-

atedoneofthesongsonmyown(theonein

Utopioca).Icreatedaroundhalfofthemusicin

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SPOTLIGHT WELCOME TO THE WORLD OF KNYTT

DEV.MAG ISSUE 166

Knyttthough.EarlierIwasplanningtomaking

musicas acareer, butat themoment,things

lookslikegamedevelopmentismybestchance

foracareer...

You have a whole community of fans help-

ing you on Knytt Stories. How do you find

working with such a community??

ItsgreatfunIgotaninsaneamountofhelpde-

signingtilesetsforthegame,whichiswhyKnytt

Storieswillcomewithalibraryof256tilesets

thatcanbeusedinleveldesign.Mostgames

justcomewiththegraphicsthatareusedinthe

gameitself(ofcourse,KnyttStorieslevelscan

featuretheirowncustomgraphicstoo).

Ico was a huge inspiration for Knytt. Do

you think games like these are grossly un-

derrated?

IcantsayIcoisunderrated,althoughIconever

becameahugecommercialsuccess(ifIdont

rememberwrong,thatis).Thereviewersreally

lovedthatgame,andgaveitthefeedbackitde-

served.Butyeah,Idlovetoseemoreofthose

kindofgames.

Do you want to continue working on small

games like these, or are you interested in

getting into the major game industry?

Imopenforanything,aslongasIdonthaveto

sacrificethepersonalityofmygames.Inother

words,Idratherkeepreleasingsmallproduc-

tionsthanjoiningabigcompanyandhelpout

designinggamesthatIdontreallylikeorhave

any control of. A smallcompanywith people

whosharemyideaswouldbetheidealthing.

What recent game that you have played

made you sit up and say Wow, this is ge-

nius?

Shellblast by Vertigo Games is fantastic, al-

thoughIneverlikedthewaronterrorphrase

usedinit(negativeassociations).Itsportable

too!

language? Do you think there is a place

for games not made in English?

YourenotlikelytofindKnyttintheaveragedic-

tionary,butitsstillawordsometimesusedto

describesmall harmlesscreatures.Originally,

thewordwasinventedbyToveJansson(the

childrensbookauthor)knownfortheMoomin

trolls. Theparticular bookthat usesthe word

is titled Vem ska trsta knyttet? (which is

translatedtoWhowillComfortToffle?inthe

Englishversion).Icanhighlyrecommendthis

childrensbook.

Abouttheotherquestion:yeah,Ithinktheres

aplaceforgamesinanylanguage,butaswith

allotherthings,youcangetawideraudienceif

thegameisavailableinalanguagethatmore

peoplespeak.

TROOJG

Quick Questions ... 3 ... 2 ... 1 ... Go!

Pizza or Pasta?

Pasta

PS3, Wii or Xbox-360?

XBoxhavealwayshadmoregoodgames,

butPlaystationhavealwayshadthemostin-

terestinganduniqueproductions(although

thereareonlyaveryfewofthem).Imgonna

havetogowithPS3.

The Simpsons or Family Guy?

Simpsons

Guitar or Piano?

Piano

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When Iwas approached towriteanice little opinion piece for Dev.

Mag,Ifoundmyselfsittinginfront

ofmywordprocessingapplication,staringrath-

erblanklyatthescreen.Onlyhavingdonelow-

levelprogramminginhighschool(intheformof

TurboPascal7.0)IcametorealizethatIdont

really know much about game development

- and thatwhichI doknow, isnowherenear

enoughtofillawholeopinionarticle.Afterall,

themostIvedoneintermsofgamedevelop-

ment,isalittletext-basedRPGofepicfailure.

SowhileIstartedtypingoutspacefillerabout

howlittleIactuallyknowaboutgamedevelop-

ment,andhowwhatI did knowwouldnot be

sufficientenoughtofillacolumnithitmelike

aproverbialbricktothehead;insteadofwast-

ingallthisspace,wafflingonlikeapretentious

git,IshouldwriteaboutsomethingIdoknowa

lotabout:

Boyohboy,doIlovetotellagoodstory..

Itshouldbeobvioustomostpeople,thathav-

inggoodprogramminginagame,althoughex-

tremely important, isntalwaysgoing tomake

your game the winner. Every game needs a

story; from a plumpplumber in red savinga

pinkprincessfromadragon-thingwithaspiked

turtle shellon his back, toa journey into the

horrorsofonesownmindtofacepsychological

demonsbroughtouttoattackyou,bysubcon-

sciousguilt.Iwouldevenhazardaguessthat

OPINION WHAT YOURE THINKING

them.Therecouldbeminorormajorobstruc-

tions hemust overcome, or even strawberry

generalsto destroy thereareno limits from

thispointon.

Itmaysoundlikearidiculousstory,butifyouve

readupuntilthispoint,itmusthaveintrigued

youinsomeway.Withoutastoryforyourgame

to work on, your game isnt going to make

muchsensetotheplayer.WhyamIshooting

thesepeople?Wherearethesechickenscom-

ingfrom?Whatisthepointofcollectingallthis

ham? These are the kinds of questions you

needtoanswer.

Ifyoucansellsomeoneacompellingstoryofa

braveyoungorangesavinghispeoplefroman

evilstrawberrysiege,andhaveitmakesense

inthecontextofyourgame;youjustmighthave

somethingsolidtostartworkingon.

Q-MAN

If you fancy saying something about game development and have enough

faith in your writing ability to do so, feel free to submit content to our

monthly opinions section.

Send your work, 400-500 words in length, with the subject title Opinion

Submission to [email protected], and you may just wind up in our pag-

es. Please note that we reserve the right to decide what material is suitable

to publish in the magazine.

DEV.MAG ISSUE 168

The Dev.Mag staff does not expressly support or agree with the views of guest columnists in this section. In fact, the Dev.Mag

staff does not expressly support or agree with the views of Dev.Mag staff writers in this section.

Its a crazy world, isnt it?

A really juicy

story

evengamessuchasTetriswerecreatedwithsomeformofworldinmind.

Soweremakingagameright?Ok,soletsget

started then.Beforewecaneven think about

programming anything,weneedsomesort of

concept.Oranges.Orangesthatarealive.Lets

workwiththat.Wherearetheselivingoranges

found?Letsjustsaytheyrelivinginthemagi-

cal city ofCitrus, where the buildings are all

fruityandbright.Weregoingtonowintroduce

ourmaincharacter,Oscar,whoisjustanevery

daykindoforange,goingabouthiseveryday

orangeystuff.

Ohdear,butthatwouldbeaboringconcept(un-

lessitwereafruitcitysimulatorcoveredinan-

otherarticlesometimeperhaps)soweneedto

bringsomesortofconflictinhere.Strawberries!

TheevilstrawberrieshavedeclaredwaronCit-

rusCityandhavebesiegedthetown,takingall

oftheorangescaptivetobesqueezedfortheir

juicestomakesugar-filled,impurecold-drinkin

specialConcentrationcamps.Theonlyorange

whocanstopthemisOscar!

Nowthatwehaveourlocation,charactersand

conflict,wecanstartgettingourheadsaround

howOscarwillgoaboutsavinghispeople.Ido

believe this is the pointwhere programmers

ears should prick up. AsOscar rolls through

thecity,heencountersevilstrawberrieswhich

hemusteitherpower-chargethrough,bomb-

drop on, ormerely avoid, by bouncing over

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9

NewgroundsNewgroundsNewgroundsNewgrounds

REVIEW ON THE WEB

imple,quickandeasygamesareking

intheworldofcasualgaming.Inthis

vein,itisnosurprisethatflashgames

are immensely popular online, with

numerous flash-gameportalsappearingallover the web.Nothing isquicker oreasier

than navigating your browser to your

favouriteportalandselectingagame.

Newgroundsislikelythelargestflashportal

around, boasting over a million registered

users and 300 000 submissions, including

flashvideosandgames.Sinceitsfoundation

12 years ago, Newgrounds has done for

flash gaming whatYouTube did foronline

video.

Part of its success can be attributed to a

largeandactivecommunity,spurredonbya

ranking system that rewards users for

participatinginthesite.Ratinggamesscores

users Grounds Gold which places more

weight behind future

votes, as well as

increasing the users

rank,earningtheusermorerespectinthecommunity.

To keep the site fresh,

submissionsthathave

alowaggregatescore

are automatically

removed from the

website,orblammed.To

encourage fair voting, the

websiteawardsblam/protectpointstousers

whosevotesaccuratelydepicttheeventual

fate of the game. These points alsocontributetowardsausersrank.

Newgrounds has been home to many

popular flash video and game series,

S

DEV.MAG ISSUE 16

including Salad Fingers and Super Mario

BrothersZ.ItisalsotheoriginalhomeofThe

BehemothssurprisehitAlien

Hominid, whose prototype

was first displayed atNewgrounds.AlienHominid

wentontobeapopularPS2

andGamecubetitle,with a

HD Xbox Live Arcade

version recently released. The

Behemoth is also currently

working on another XBLA title,

Castle Crashers, which also

lookssettobeasuccess.

Foraquickfixofgamingfun,orforalittlebit

a humour, Newgrounds is always a greatplacetolookforaqualitydiversion.

CHIPPIT

WebsiteWebsiteWebsiteWebsite

http://www.newgrounds.com/

UpdatedUpdatedUpdatedUpdated

Continuously

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10

BLENDER INTERMEDIATE TUTORIAL:BLENDER INTERMEDIATE TUTORIAL:BLENDER INTERMEDIATE TUTORIAL:BLENDER INTERMEDIATE TUTORIAL:

Converting 2D to 3DConverting 2D to 3DConverting 2D to 3DConverting 2D to 3D

DESIGN ENTER THE 3D WORLD

onverting2Ddrawingsinto3D.Yep,

thatsoundsprettycool,right?Inthis

articleIwillshowyouhowtotakea

2D design and transform it into 3D. Yes,

there are limitations, but what we can do

heremightjustcomeinveryhandy.

WewillusetheGIMP,consideredthebest

Open Source alternative to Adobe

Photoshop. In the GIMP we wi ll draw

something,selectthatdrawingandusethe

GIMPtocreateanoutline.Theoutlinewillbe

exportedoutoftheGIMP,andimportedinto

Blender. Blender will then add the 3D

element.TheGIMPcanbedownloadedfrom

www.GIMP.org.

Forthistutorialwewillcreateasimplegame

interfacescreenusingthefollowingsteps:

DrawinGIMP

Selectthedrawnbits

ConverttheselectiontoapathExportthepath

ImportthepathintoBlender

Adddepthtotheobject

Let'sgetgoing.FireuptheGIMP.Assuming

thatmygamescreensizewillbe800X600

pixels,Iwillcreateanimageofthatsizein

theGIMP.Whatactuallyhappensisthatyou

can scale the object toany size once you

haveitinBlender,butitiseasiertoworkwith

theactualdimensionsintheGIMP.Thebest

suggestionIhaveforcreatingadesignthat

will work well

for conversion

into3Dis:

Todo the

design in one

colour only.

Thismakesiteasyfortheselectiontoolto

selectonlythatcolour.

Yourdesignpiecescannothaveholesin

them.Iftheydo,you'llneedtothinkcarefully.

Now,usetheSelectregionsbycolourtool

toselectacolourontheimage.Youshould

see the single colour surrounded by a

flashingdottedoutline.Nowthatwehavea

selection,weconvertthattoapath.Apath

isalsocalledavector,orcurve.Itisawayof

C

DEV.MAG ISSUE 16

describing an

outline in

mathematically

precise terms.

You can then

scale or move

thatlinewithout

losing any

quality. Use

Select --> To

Path to convert

our selection

into a path/

curve/vector.

Now,openthePathsdialog.Selectthepath

oujustcreated,rightclickonit,andchoose

ExportPath.Typeaname,andbesureto

include the extension. Call the file

interface.svg. The .svg extension is for

scalablevectorgraphics.

Now,finally,wegettoBlender.Herewecan

nowimportthefileasaGIMP2.0file,giving

us the outline of what we created in 2D.

Pleasedelete everything you have inyour

scene. Easiest way isto AKEY (select all)

andDELETEKEY.NowgotoFile-->Import

-->Paths(svg,.ps).ChooseGIMP2.0in

thenextmenu.Browsetothelocationofyour

exportedpath.svgfile,andselectthatfile.

Next, just click onImport Path,and click

OKintheimportoptionsmenu.

(IfyourenewtoBlender,checkoutDev.MagIssue5forthebeginningofourBlendertutorialseries!)(IfyourenewtoBlender,checkoutDev.MagIssue5forthebeginningofourBlendertutorialseries!)(IfyourenewtoBlender,checkoutDev.MagIssue5forthebeginningofourBlendertutorialseries!)(IfyourenewtoBlender,checkoutDev.MagIssue5forthebeginningofourBlendertutorialseries!)

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11

DESIGN ENTER THE 3D WORLD

Welldoneifyougotthisfarwithouthassles!

Mostpeopledon'teventhinkofthisoptionof

combining2Dand3Ddesign.

You now have a curveobjectin Blender.

Youoptionsare:

Usethecurveoptionsmenutoextrudethe

outlineinto3D

Converttheoutlinetoa meshandwork

fromthere.

I'mgoingtousethecurvemenuoptionsto

extrudethe outlineintoa 3Dshape.Go to

theEditbutton.Thisiswhereyou'llfindthe

curveoptions:

Extrude:Makestheobject3D

BevelDepth:Addsbevellededge

BevReso:Smoothesthebevellededge

Idecidedtobringtheoutsideorangeborderinasacurve

aswell.Inthiscase,Blender

founditeasytounderstand

the curve. It consists of a

rectangle (4 points) on the

insideandarectangleonthe

outside(4points).Youmay

find that if your shape is

more complex, GIMP will

use different numbers of

points to define thecurves,

whichwillleadtounreliable

results in Blender. There

are,however,waystosolve

theseproblems,buttheygo

beyondthescopeofthisspecifictutorial.

Afterimportingtheorangeoutlineaswell,my

Blendercurveobjectslookliketheimageto

theright.

Ihadaside-scrollingspaceshooterinmind,

soIwillchangethecoloursandpresentation

oftheinterfacetoreflectthat.Ialsoedited

thecurveontheoutsidesothatIcouldhave

space on the left to add some interface

buttonslateron.

DEV.MAG ISSUE 16

Iwon'tbeenteringthisdesignforanygaming

competitionsascandidateforbestinterface

design, but I trust that your creative spirit

maytakesomethingfromthis,andapplyitto

yourownwork.

HappyBlendin',folks!

?RMAN

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12

Beginners Guide to MakingBeginners Guide to MakingBeginners Guide to MakingBeginners Guide to Making

Games - BackgroundsGames - BackgroundsGames - BackgroundsGames - Backgrounds

DESIGN HELPING YOU ALONG

his is the third article in the Beginners Guide to Making

Games.Sofar,wehavelookedatmakingobjectsmoveand

checkingwhethertheycollidewitheachother.Thismonthwe

willlookatvariousoptionswehaveforsettingbackgrounds

inourrooms.

ThemaingoaloftheBeginner'sGuideseriesistotryandensurea

detailedunderstandingofthevariousconceptssothattheycanbe

applied to other new and exciting games. While most traditional

tutorialswillshowyouwhatcodeisneeded,theseguideswillensure

thatyouwalkawayactuallyunderstandingeachoftheseconcepts.

This article isaimed atsomeonewhohas juststarted learningto

makegames.Whileitisexpectedthatthereaderofthearticlehas

completedthefirstGameMakertutorialandcanthuscreatesprites

andobjects,it isquite possibleto follow thearticlewithout having

doneso.Thearticleisstructuredtointroduceanewprogrammerto

theconcept,andperhapsbeofsomevaluetotheintermediate-level

programmeraswell.

Thismonthsarticlewillcontainthefollowingsections:

1. AGameMakertutoriallookingatsettingabackground

2. AGameMakertutoriallookingatatiledbackground

3. Fiddlingwi thbackgroundsinGML

BackgroundsGMTutorialBackgroundsGMTutorialBackgroundsGMTutorialBackgroundsGMTutorial

Backgroundsarecriticalinsettingthethemeandfeelofagame.In

GameMaker,it'seasytosetupabackgroundanduseitinaroom.

Step1CreatetheBackgroundStep1CreatetheBackgroundStep1CreatetheBackgroundStep1CreatetheBackground

Addanewbackground(eitherunderthebackgroundslinkontheleft)

orbyselectingAdd|Addabackgroundfromthemenu.Choosethe

imagethatyouwant.Fornow,selectanimagethatisbigenoughto

coverthewholescreen.

In most cases, backgrounds don't need to be transparent or

smoothedastheyshouldbedesignedtolookrightjustastheyare.

Ifyourbackgroundimageisnotlargeenoughtofillthewholescreen

itwillneedtobetiled.Inthiscase,youneedtomakesurethatthe

imagecantileseamlesslyfromlefttorightandtoptobottom.

Step2CreateaRoomStep2CreateaRoomStep2CreateaRoomStep2CreateaRoom

Addanewroomandnameit.Selectthebackgroundtabandselect

the newly created image as the foreground image. Uncheck the

Drawbackgroundcolourcheckbox.Itwastesprocessingpowerto

paintthebackgroundandthentodrawtheselectedbackgroundover

thepaintedbackground.

IftheimageusedforthebackgroundneedstobetiledsettheVertical

andhorizontalcheckboxesandsetthenumberofimagestotileover

thehorizontalandverticalspace.

Anotheroptionforbackgroundsistostretchasmallerimageacross

the full screen. Very small images will become very pixelated if

stretchedsoonlyimagesthatareclosetothescreensizeshouldbe

usedasstretchedbackgrounds.

TilesGMTutorialTilesGMTutorialTilesGMTutorialTilesGMTutorial

Tilesareverysimilartobackgrounds,butinsteadofusingasingle

imagetocoverthewholeroomtheimageusedto tileis splitinto

smallpiecesandaddedtothescreenbitbybittoformanimage.

T

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13


Step1CreatethebackgroundtilesStep1CreatethebackgroundtilesStep1CreatethebackgroundtilesStep1CreatethebackgroundtilesCreateabackgroundimageinthesamewayastheprevioustutorial.

ChecktheUseastilesetoption.ATilePropertiespanelwillopen

upwherethesizeofthetilescanbeset.Notehowtheindividualtiles

aremarkedasthesizeoftheeditboxes.

Whencreatinganimagetouseasatilesetmakesurethatallthe

tiles are the same size and are evenly spaced across the whole

image.

Step2CreatearoomStep2CreatearoomStep2CreatearoomStep2Createaroom

Create a new room.

Select the tiles tab.Selectthebackground

that was created as

thetileset.Ontheleft

side panelthe tile set

will be displayed. On

theright,agridwillbe

displayed (defaulting

to the whole tile set).

Onebyoneselectthe

tileintheleftwindowandclickonthegridontherighttosetthetile.

Bychoosingatileontheleftandplacingitontherightafulltiledbackgroundcanbecreated.Thisallowscomplexandcustomisable

roomstobecreatedtolooklikeaworldmaporamazeetc.

GameMakerallowsmultipledifferenttilelayers.Eachlayercanthen

bemanagedseparately.This allowsthe useof differentlayersfor

differenttypesofobjects.Thiswouldforexampleallowthecreation

ofamapinthebackgroundwithbuildingsetcontheforeground.

FiddlingwithbackgroundsinGMLFiddlingwithbackgroundsinGMLFiddlingwithbackgroundsinGMLFiddlingwithbackgroundsinGML

Backgroundsarenotthemostamazingthingstofiddlearoundwith.

However,therearesomefunthingstodowithbackgrounds.Notall

backgroundsneedtobecreatedup front.In fact,backgroundscan

becreatedwhilethegameisrunningandGameMakerhasanumber

ofmethodsavailabletomakethishappen.

AddthefollowingcodetotheRoom'sCreationcodetocreate(at

runtime)aredtobluegradientbackground.

bg =background_create_gradient(room_width, room_height,

c_navy, c_red, 0, true);

background_index[0] = bg;

room_set_background(room1, 0, true, false, bg, 0, 0,

false, true, 0, 0, 1);

background_create_gradient(w, h, col1, col2, kind,

preload)

Createsagradientfilledbackgroundofthegivensize.col1andcol2

indicatethetwocolors.kindisanumberbetween0and5indicating

thekindofgradient:0=horizontal1=vertical,2=rectangle,3=ellipse,

4=doublehorizontal,5=doublevertical.

background_create_from_screen(x, y, w, h, transparent,

smooth, preload)

Createsabackgroundbycopyingthegivenareafromthescreen.

Thismakesitpossibletocreateanybackgroundyouwant.Drawthe

imageonthescreenusingthedrawingfunctionsandnextcreatea

backgroundfromit.

CAIRNSWM

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14

Beginners Guide to MakingBeginners Guide to MakingBeginners Guide to MakingBeginners Guide to Making

Games - Part 2Games - Part 2Games - Part 2Games - Part 2


astmonth,wehadalookatdifferentwaysGameMakermanagescollisions.Thismonth'sExtrawilllookatvariousmethods of doing collision detection in 2D in otherprogramminglanguages.ThebenefitofusingGameMakerisofcoursethatyoudontactuallyneedtounderstandallthe

intricaciesoftheprocess.

Whenlookingforcollisionsbetween2Dobjectstherearetwobasicmethodsofdoingso:1. BoundingBoxcollisiondetection2. PixelperfectcollisiondetectionAthirdalternatemethodisalsopossiblethrough3. Map-basedcol lisiondetection

ManydevelopersfeelthatBoundingBoxesdonotgiveanaccurateenoughlevelofcollisiondetectionandinsistondoingmorefine-grainedcollisiondetection.Howeverinmostcasesthereisnorealvisibledifferencebetweenboundingboxandpixelperfectcollisiondetection.

BoundingBoxCollisionDetectionBoundingBoxCollisionDetectionBoundingBoxCollisionDetectionBoundingBoxCollisionDetectionBounding box collisiondetection is done by defining simple

geometricshapes around thespritesusedfor theobjectsandcheckingifthegeometricshapesoverlap.Typically,theeasiestshapestocheckforoverlaparerectangles.

The overlap of two rectangles can also be defined as theintersectionbetweentherectangleorevenmoresimplyasbeingtrue if any corner of the second rectangle is inside the firstrectangle.Forexampleifeachrectangleisdefinedbyx1,y1asthetopleftcornerandx2,y2asthebottomrightcornerwecandefineacollisionanytimerectangletwosx1orx2isbetweenrectangleone'sx1andx2andthesamefortheycoordinates.

Function BoundingBoxCollision(rect1, rect2 : rectangle)

{

If ((rect1.x1 < rect2.x1 and rect1.x2 > rect2.x1) or

(rect1.x1 < rect2.x2 and rect1.x2 > rect2.x2)) and

((rect1.y1 < rect2.y1 and rect1.y2 > rect2.y1) or

(rect1.y1 < rect2.y2 and rect1.y2 > rect2.y2)) then

Result := true

Else

Result := false

End if

}

Boundingboxesareusuallysmallerthanthefullsizeofthespritebeingusedasthepictureofthespritewilloftenbesurroundedbyatransparentborder.Inaddition,theboundingboxcouldalsobedefinedasacirclewithacertainradius.Ifthedistancebetweentwocirclesislessthantheircombinedradius,thereisacollision.

Iftheshapeofaspriteisnotgenerallyrectangularorcircularitis

alsopossibletodefinethecollisionareaofaspriteasacollectionofshapes and check for collision with anyof the bounding boxshapes.

PixelPerfectCollisionDetectionPixelPerfectCollisionDetectionPixelPerfectCollisionDetectionPixelPerfectCollisionDetectionPixelperfectcollisiondetectioniswhereeachpixelofthetwospritesischeckedtoseeiftheyareinthesameplaceaseachother.Duetothenumberoftestsneededtoimplementpixelperfectcollisiondetection, it should onlybe usedwhenboundingboxcollisiondetectionisclearlynotaccurateenough.(suchaswhen

checkingifastarfishandanoctopuscollide).

Ofcourse,itisnotnecessarytocheckeverysinglepixelofthetwosprites,infactinmostcasesitwouldbesufficienttouseonlytheoutlineofthespritesoreveninmanycasesjustafewoftheoutlinepixels.

Typically, pixel perfect collision detection is used alongwithboundingboxes.Ifaboundingboxcollisionisdetected,thenmoredetailedtestsaredonetocheckthatthereareinfactpixelsthatcollidewith eachother.Bywrappingthe pixelperfectcollisiondetectionwithinalesscomplextesttheperformanceimpactofthepixeltestingisminimized.

Map-basedCollisionDetectionMap-basedCollisionDetectionMap-basedCollisionDetectionMap-basedCollisionDetectionMapbasedcollisiondetectionworksonthepresumptionthatfirstly

youknowwhereinthegameworldeachitemisandsecondlythatonlyoneitemcanexistineachspaceoftheworld.Byusinganarraytorepresenttheworldandstoringalinktotheitemthatexistsineachspaceitsasimplechecktofindwhichobjectisinwhichspaceatanytime.Theuseofanarraytostorewhereeachandeveryitemofthegameis,makesitalotquickertocheckforacollision.

Wheneveranobjectmoves,itisfirstremovedfromtheworldarray,itsnewlocationiscalculatedandthearrayischeckedtoseeifanotheritemisalreadyintherequiredlocation.Ifnoitemisfoundinthedestinationlocation,theitemisagainaddedtotheworldarray.Ifanitemisalreadyinthelocationtheitemwantstomovetoacollisionbetweentheobjectsiscreated.

Map-basedcollisiondetectionoftenrequiresobjectstocheckforcollisionsinmorethanonelocationintheworldarrayduetothingssuchasitemsizeor just tomakethecollision checkingmorerealistic.Buildingsaretypicalexamplesofwhereanitemneedstoexistinmorethanonemaplocationsimultaneously.

Map-basedcollisiondetectionisoftenverysuitedtoisometric-stylegames.

ChoiceChoiceChoiceChoiceThechoiceofcollisiondetectionmethodisoftenbasedonthegamebeingdeveloped.Eachmethodofcollisiondetectionhasitsplace.Mostgameswillfindthatboundingboxesaresufficientfortheirneeds.

CAIRNSWM

L

DEV.MAG ISSUE 16

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WellwellThisserieshascomea

longwaynow.Itsalmostayear

sinceitstarted.Aftertheprevious

article,IhavenothadtimetoworkonRoach

Toaster2duetoholidays,workandschool.

AsIwritethisarticle,Ihaveoneweekofschool

left.Afterthat,itsalljustexamsuntiltheendof

theyear.Thisisalsomysenioryearinschool,

somyworkwilltakepriority.

Inpreviousexams, I haveworked ongames

throughout,butasIsithere,Iamnotquitesure

ifIwillhaveenoughtimetoreallypayattention

toRoachToaster2duringtheexams.

RT2hasbeenthroughthickandthin.Itstaking

memuchlongerthanexpected.AsIhavemen-

tionedpreviously,IthoughtIwouldbefinished

withbetabyDecember2006.

So,consideringthatIdontreallyknowwhatwill

happenandRT2stumultuousdevving,Ihave

decidedtoendthisseriesfornow.Youwillmost

likelyseeapost-mortemonceitisdone,ora

beta-feedbackarticle.

So,IthoughtIdusethisarticletoonceagain

explainwhatRoachToaster2anditsdevelop-ment.

What the bug is Roach Toaster 2?

RoachToaster 2 isthe sequel tothe award-

winningRoachToaster1.Byaward-winning,I

meanitwonaninternationalandlocalcompeti-

tion.RoachToaster2alsowonaplaceinalo-

calcompetitionasaWIP(WorkInProgress).

RT2 places you inthecommandof teamsof

roachtoastersasyoudefendBigCityfrombe-

ingdestroyedbyaroachinfestation.

Itcontainsmulti-levelgameplay.Youmustman-

ageyourteamsonacity-widescaletoobliterate

theroaches.Theoriginalandaddictivegame-

playfromRT1isstillhereinanewguise.With

updated gameplay and new enhancements,

eachlevelwillbeauniquechallengethatcan

betackledthewayyouseefit.

What is the story behind RT2?

Afteryoudefeatedyourneighbourhoodsroach-

esinRT1,yourteamsetofftoCancunetoen-

joyawell-deservedholiday.Wheredidtheyget

themoney?Dontknow,butwhocares?

Unbeknownst to them, theBroodmotherincu-

batedinsidetheHoover.Shethencameback

withavengeance.Sheislivid,andwantstode-

stroyBigCityonceandforall.

Youmustdefeather.

ROACH TOASTER 2: PICKING OUT THE BUGS

PART 7

PROJECTS LEARNING HOW ITS DONE

Wheredidyougetallthemoney?Istheresome-

thinggreateratstake?World-domination?Find

outwhenRT2getsreleased.

RoachToaster2hasbeenanimmenselearn-

ingcurveforme.Itsbeenmypuppyformore

thanayearnow.Despiteeverythingelsethat

occupiedme,Ialwayshadtimetofitinabout

ofRT2devving.

Icantwaittofinallycompletethefinished,pol-

ishedproduct.

Let me finish by saying that I already have

RoachToaster3plannedout.Howitwillplay,

orwhatitwillbe,willhavetowait.

Keeptoasting!

For more info onRoach Toaster 2:Big City,

head on to http://www.shotbeakgames.za.net

orthenewsitehttp://www.roachtoaster.com

TROOJG

DEV.MAG ISSUE 1615

( Wondering what were talking about over here? check out Dev.Mag Issue 10 for the beginning of this Project series! )

8/14/2019 Dev.Mag - 16

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minimalamountofeffort.Italsoprovidesmuch

morecomplexdocumentationfeaturessuchas

call graphs, dependency graphs, inheritance

diagrams,andcollaborationdiagramsforthose

developerswhowantto integratethesemore

complexfeaturesintotheirprojectdocumenta-

tion.AnothergreatthingaboutDoxygenisthatit

hasnativesupportformostofthemorepopular

languagessuchasC,C++,C#,Java,Python,

andevenPHP(sorry,nonativeDelphisupport!).

The documentation that is generated by

Doxygencan beoutputintoHTML,PDF,and

(my personal favourite) compressed HTML

(CHM), amongst other formats. The ben-

efits of having this documentation generated

for you automatically should be fairly obvi-

ousasitprovidestheabilitytohaveyouren-tire code base documented inwhatever form

suits you (ie. PDF for reading or printing, or

HTML/CHM for PC-based hyperlink naviga-

tion and searching), with very little overhead

onthepartofthepersonwritingthecomments.

This documentation can then become a very

important tool for your team as it will allow

programmers toeasily search forand seein-

formation (in an easily accessible and read-

ableformat)onany codethattheymayneed

todealwith.Thisfunctionalitybecomesextra

Itisafactofprogramminglifethatprogram-

merswillmakemistakesintheircode.These

mistakesorerrorsarenotusuallydownto

bad programming or any lack of talent, but

merelyduetothesheerscopethatmostpro-

gramsarecomprisedof.Whenanyoneprogram-

merischurningouthundredsuponhundredsof

linesofcodeaday,itsonlyamatteroftime

beforesomeofthoselineswillcontainerrors.

Asdiscussedinthesecondarticleinthisseries,

propercommentingofcodeisaveryimportant

partofgamedevelopment.Buildinguponthis

idea,peoplehavegoneaboutdevelopingsys-

temsthatallowfordeveloperstoeasilycreate

fully featured documentationof theircodeby

merelyalteringtheircommentstoincludemark-

erswhichthenallowthecommentsthemselvestobeconvertedintodocumentation.Onesuch

systemthatallowsthis,andthatIfullyadvocate

the use of, is Doxygen (www.doxygen.org).

Doxygenisincrediblyusefulbecauseitisvery

simple and straightforward touse inits most

basicform,andtheresultsthatyoucanobtain

fromitareterrificforanyonemanagingthecode

baseofa project.It allows very robust docu-

mentation tobe generated for all ofthemost

important areas of your code such as files,

functions,variables,anddatastructureswitha

helpfuliftheyaredealingwithsectionsofcode

written byotherprogrammers, andespecially

soiftheoriginalwriterofthecodeisnolonger

onthe teamorisnt available toask for help

in understanding the code that they wrote.

ThebasicideabehindDoxygenisthatitlooks

forandparsesvarioustokenkeywordsthatare

placedinsideof speciallyformattedcomment-

ingblocksthatworkinsideofthelanguageyou

arewritingyourcodein.Therearefourkinds

ofcommentingblockssupportedbyDoxygen,

and any Doxygen keyword that is found in-

side ofthese comment blockswillbe parsed

andusedfordocumentationgeneration,while

any keywords found inside of the standard

languagecommenting blocks willbe ignored.

Supported Commenting Block Formats:

/** addcommentshere... */

/*! addcommentshere... */

/// addcommentshere...

//! addcommentshere...

Onethingthatyoumustnoteisthatbydefault,

Doxygen assumes that the code being com-

mentedonislocatedafterthecommentblock.

InordertotellDoxygenthatthecodeisactually

located before the comment block, you must

CODING ETIQUETTE:

DOXYGEN

TECH ELECTRONIC PLAYGROUND

DEV.MAG ISSUE 1616

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\param--Usedtomarkeachparameterofa

function

\return--Usedtomarkthereturnvalueofa

function

Doxygenalsoprovidesvariousmiscellaneous

keywordsthatcanbeusedatanytimeinorder

tomarkvariouspointsofinterestinthecode.

These keywords are very helpful in creating

morerobust documenation,especiallyfor the

purpose of adding specific types of notes to

complement themoretechnicalnatureof the

documentationrelatedtothecodeitself.

Misc Doxygen Keywords:

\ref--Createsahyperlinkreferencetoaspe-

cifickeyword

add a extra

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TECH ELECTRONIC PLAYGROUND

DEV.MAG ISSUE 1618

Simple Example of Doxygen Commenting

/**

\file vector.cpp

\author Luke Lamothe

\date Saturday, 18 August, 2007

\version 1.0\brief File containing vector math utilities

*/

/**

\struct tVec2D

\brief Structure that defines a 2-dimensional vector

\note There is a \ref tVec3D structure for use if you need to use 3-dimensional

vectors

*/

typedef struct

{

float x; ///< The x component of the 2D vector

float y; ///< The y component of the 2D vector

}tVec2D;

/**

\struct tVec3D

\brief Structure that defines a 3-dimensional vector

\note There is a \ref tVec2D structure for use if you need to use 2-dimensional

vectors

*/

typedef struct

{

float x; ///< The x component of the 3D vector

float y; ///< The y component of the 3D vector

float z; ///< The z component of the 3D vector

}tVec3D;

/**

\param psVecA The first vector to use in the dot product calculation

\param psVecB The second vector to use in the dot product calculation

\return float The result of the dot product between the two vectors

\brief Utility function to calculate the dot product between two 2-dimensional

vectors

*/

float Vec2DDot(tVec2D *psVecA, tVec2D *psVecB)

{

float fResult;

//calculate the dot product of the two vectors and return it

fResult = (psVecA->x * psVecB->x) + (psVecA->y * psVecB->y);

return fResult;

}

/**

\param psVecA The first vector to use in the dot product calculation

\param psVecB The second vector to use in the dot product calculation

\return float The result of the dot product between the two vectors

\brief Utility function to calculate the dot product between two 3-dimensional

vectors

*/

float Vec3DDot(tVec3D *psVecA, tVec3D *psVecB)

{

float fResult;

//calculate the dot product of the two vectors and return it

fResult = (psVecA->x * psVecB->x) + (psVecA->y * psVecB->y) + (psVecA->z * ps-VecB->z);

return fResult;

}

8/14/2019 Dev.Mag - 16

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Welcome back, fellow coders! Pre-

pare yourselves for the final,

bumper episode of the Trig Tril-

ogy, where I cover a whole lot of awesome

trig techniques for your game-making plea-

sure.Wevegot a lot to cover, so lets jump

right in. Its time for my first trick! Now, as

youcansee,thereisnothingupmysleeve...

Relative Angling 101

Nomatter what kind ofgameyoure working

on, moreoftenthannot youll need tocalcu-

late the anglebetween two objects for some

reason.Itstimetolookatachunkofcodethat

canmake your life very easy in this regard:

Whatthis codedoes is firstcalculate thedif-

ference in x and y coordinates between

the two objects, then divide as per the arc-

tan ratio. X1 and Y1 represent the coordi-

natesof the object you want tocalculate the

angle from. X2 and Y2 are, obviously, the

coordinates of the object whose angle youwant to measure relative to the first object.

Weperformthesubtractionbecausealltrigcal-

culationsassumethatouroriginisatpoint(0,0)

ontheCartesianplane.As aresult,weneed

to use relativemeasures, essentially making

point(X1,Y1) our origin .If thisall seemsre-

allyconfusing toyou,worrynot.Ive summed

itupforyouinthesetwodiagrams.Asyoucan

see,theresamassivedifferencebetweenthe

twodependingonwhetheryousubtractornot!

Onefinalthingtonoteisthatthisalgorithmwill

giveyoutheangleinradians,aswasdiscussed

lastmonth.Remember toconvert theanswer

todegrees if thatswhatyour game requires!

Andthere you haveit: all you needto know

about calculating the relative angle between

twoobjects!Thatwasntsocomplicated,wasit?

Goin Round in Circles

Oneof themostprevalentproblemsthatfirst-

time coders have is making objects follow

a circular path. There could be any number

ofusesforthishavingatargetingreticleor-

bit around your game character, or perhaps

GAME CODING WITH TRIGONOMETRY

PART 3

TECH WHEN MATHS GETS USEFUL

DEV.MAG ISSUE 1619

Figure 1a: Angle calculated without subtraction

Figure 1b: Angle calculated with subtraction

GAME MAKER TIP:

There are several functions you can use

in GM to calculate your angles. You can

use the same algorithm as above or use

the slightly altered arctan2(y,x) function,

meaning you dont have to divide first. By

far the easiest, however, is to use the point_

direction(x1,y1,x2,y2) function, which

also converts the angle to degrees for you

as a little added extra! The choice is yours.

( What manner of trickery is this? To delve into the mysteries of trigonometry properly, maybe Dev.Mag Issue 14 would be a better starting point! )

8/14/2019 Dev.Mag - 16

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within a set distance of that centre.We cando that using the following two algorithms:

centreX and centreY refer to the coordi-

nates of theposition/objectwewantto rotate

around.Itsimportantthatwehavethese,oth-

erwise(aswithouranglecalculations)theob-

jectis going torotatearoundthe screen/level

origin (0,0) instead of the centre we want.

Radiusis obviously the radius ofour circle,

andAngleis therelativeanglebetween the

centre and the orbiting object. Changing the

Anglewillrotatetheobjectaroundthecentre.

IncreasingordecreasingtheRadiuswillmove

theobjectfurtherfromorclosertothecentre.

Changing the centreX and centreY coordi-

nateswill,ofcourse,movethecentreandthe

spinningobjectwithit.Thatsallthereistoit!

Afinalnote. Ifyoureimplementingaspinning

object where you keep increasing the angle

tocreate rotation,itswiseto resettheAngle

to0onceit exceedsthemeasureforonefull

rotation (either 360 degrees or 2 radians).

Although it shouldnt make much difference

to your calculations, it certainly keeps things

cleaner, and ensures that you know exactly

what rangeof numbers your code isworking

with. This can make debugging a lot easier.

a spinning-blade-on-a-chain trap for haplessplayers to wander into. Either way, if youve

ever wanted to have one thing spinning

aroundanother,thisisexactlywhatyouneed!

Fortunately,circularpositioningisnotatall diffi-

culttodoforusmightytrig-wielders.Asalways,

lets look at exactly what were trying to ac-

complishhereintheformofahandydiagram.

Figure2depictswhatiscommonlyreferredto

asacircle.Thisshapeisnotablebecauseit

hasaconstantradius.Thatmeansthatregard-

less ofwhere you are on the circumference,

youllbeexactlythesamedistanceawayfrom

the centre. This gives us an important clue.

Figure 3 depicts our situation more clearly.

What we really want to do in code terms is

to calculate the x and y coordinates of an

object while ensuring that, regardless of

its angle to the centre, it always remains

Whats this? Theres more?

Yes! Sometimes you may want an object

to move in an elliptical fashion, especially if

youre creatinganisometric gamewhere the

perspective means that you need ellipses

to represent circles and circular movement.

Fearnot, goodpeople!By alteringthe radius

values in the circular positioning algorithms,

wecanmakeobjects followanellipticalpath.

The trickistorealizethat theradiusinanel-

lipseisnotconstanttheradiusforitsvertical

proportions isdifferent from the radius for its

horizontal proportions. For instance, the first

ellipse inFigure 4 has a verticalradius of2,

whichis halfof its horizontalradiusof4.We

needtoaltertheradiusvaluesinouralgorithms

toreflectthisdistortedrelationship.For thefirst

ellipse, our expressions would look like this:

For the second ellipse, our ex-

pressions would look like this:

Im sure that the relationships between the

radii that you specify and the ellipses pro-

portions are becoming crystal clear to you.

Other than that, the code works in exact-

ly the same way as with a regular circle.


DEV.MAG ISSUE 1620

Figure 2: The humble circle

Figure 3: Shazam! Trigd!

GAME MAKER TIP:

Game Maker makes things easy for you

again by providing the lengthdir_x(len,dir)

and lengthdir_y(len,dir) functions. These

take your circle/ellipse radius (len) and di-

rection (dir) and calculate the correct x and

y values for you just like we did above. No

mess, no fuss, and you can use them any

time you need to resolve an angled line to

x and y coordinates, not just with circles.

Just remember to add the centreX andcentreY coordinates to the final answers!

Figure 4: Ellipses gone wild

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Here are the algorithms you would use:

Thesealgorithmsareactuallyverysimilartothe

onesweuseforcircularpositioning.Asbefore,

Radius will determine themaximum distance

fromthecentreourobjectcanmove,andAngle

willdetermineatwhatpointinthewaveourobject

is.However,anessentialthingtonoteisthatwe

nolongerhavetouseSinforverticaldisplace-

mentandCosforhorizontaldisplacement,be-

causewereonlydisplacingalongoneaxisnow.

Lets back up abit. If we dont have to care

about using Sin or Cos, whats with the big

OR in there? Well, it depends on how you

wantyourwavetobehave.OscillationusingSin

orCosresultsinslightlydifferentwavepatterns:

TheSingraphbeginsitsmotionatadisplace-

mentof0.ThismeansthatusingSinasyour

trigfunctionwillresultin yourobjectsmotion

startingat the centre pointyou specify.Like-

wise,theCos graphbegins its motion atthe

maximum point, so usingCos as your func-

tion for oscillation will result in your object

starting at the maximum radius youve set.

Wave Motion - Cowabunga!

Forourfinal trick,weregoingto coveravery

useful functionof trig creatingwavemotion

(oroscillation),for gameobjects.Everplayed

a scrolling shooter where the enemy ships

move in a wavy pattern across the screen,

or stood amazed at the helical particle trail

leftby aweapon?Well,hereshowitsdone!

All the time thatwevebeendoing trig,youll

havenoticedthatwevebeenusing twoalgo-

rithmsonetocalculatetheX(horizontal)co-

ordinate,and another tocalculatethe Y (ver-

tical).Asyoulearnedwhilewewerecovering

circlesandellipses,wecanusethetwotocre-

aterotationaroundan object.Alteringthe ra-

diusvaluesforeitherequationletsuswarpthe

circles proportions, creating ellipticalmotion.

Have you asked yourself what would hap-

pen if we left one of the calculations out?

WhatifweneglectedtocalculatetheXvalue?

What if we left the Y value out in the cold?

Well, wed still get movement, but it would

be exclusively on the axis for whichwe cal-

culated it.Thats themagicbehindwavemo-

tion. To demonstrate, yet another diagram:

Thearrows in figure 5 illustratethe rotational

motion.You should notice thataswe reduce

the horizontal components radius to zero,

therotationbecomeslesscircularandmore

wavy,wobblingbetweentheradiuspointsand

thecentre.ThepointthatImtryingtoconveyis

that,usedalone,atrigfunctioncanbeusedto

introduceoscillationto anobjectsmovement.

Sohowdoesthistranslatetoourcode?Well,forexample,willresultinoscillationalongthexaxis

startingatthecentre,whilewillresultinoscilla-

tionalongtheyaxisstartingattheradius.Clear?

Onefinal thing. Youmayalready havegath-

ered this,butit ispossible toalterthespeed

of oscillation by multiplying or dividing your

Angle variable. You can use this to easily

change how quickly the object moves along

the wave. Multiplication will make your ob-

ject oscillate faster, whiledivisionwill slow it

down.Thiscan resultin quitea few interest-

ingspecialeffectsorchallengesinyourgame.

Its Over!

This marks the end of this little introduction

to game programming with trigonometry. As

youve seenover thepast three installments,

trig has anincredibly wide rangeofeffective

uses when programming games. Hopefully

youve not only grasped the techniques cov-

ered here, but youve also gained the abil-

ity to apply trig to whatever problems you

may come across when coding inthe future.

Properly applied, trig is a highly flexible, in-

credibly powerful tool in your programming

arsenal,especially ifyou plan oncreating3D

gameslateron.Goodluck,andhappycoding!

GAZZA_N


DEV.MAG ISSUE 1621

Figure 5: Thinner and thinner

Figure 6: Sin and Cos graphs

8/14/2019 Dev.Mag - 16

22/32

Optimisingdata,optimisingcode ...it

allsoundslikesuchawaste.Thisar-

ticleoutlinessomesimpleandeffec-

tivestrategiesonspottingandfixingbadcode

concepts,whichslowaprogramdowninmore

waysthanone.Wewilllookatthesestrategies

andcoversomenewideaswhichareallrelativeto creating games, especially when stepping

out into coding your own engine orevenjust

coding.Regardless ofthe applicationorcode

usage,optimisationisimportantyetoverlooked.

Writingcutting-edgegamesisonallofourto-

dolist,butarewereallyTRYINGtogetthere,

orareweinafrenzytolearnasmuchaswe

can as soon aswe can, skipping vital steps

which get us to a better rounded end prod-

uct? Im making this statement as it is one

which resides in my mind whenever i step

into any project. Rather take the time and

makeamasterpiecethanskipafewstepsand

end upwith anotherproject toreviseand fix.

Lets see what we have here...

Optimisation: Modifying a system to improve

its efficiency whether its a single loop, a

single program, or even the entire Internet.

Profiling:Settinguppointsincodethatcountthe

numberofclockcyclesand/ortimeittakesto

executecertainblocksofcode.Thiseffectively

singlesouttheslowcodeinyourprogram/sys-

temandallowsyoutoreviseandimprovethe

system.

Code optimisation may be something out of

yourreach,orsoyouthought.Wespendtime

makinggamesandihaverunintocaseswhere

iendupwithanon-viablesolutionwhichends

upinthebin orintherevisefolder,whena

simplelookatoptimisingDURINGaprojecthas

savedmemorethanadozenwastedprojects.

Optimisation must be approached with cau-

tion.TonyHoarefirst said,andDonaldKnuth

famously repeated, Premature optimizationis the root ofall evil. Itis important tohave

soundalgorithmsandaworkingprototypefirst.

Systemdesignandtheinternalarchitectureof

thecodeisthelargestweightonperformanceof

asystem.Thechoicesinthisstageaffecteffi-

ciencymorethananyotherareaduringdesign.

This was something i read recently which

has quite the obvious pointed out to

you to look carefully at optimisation:

Premature optimization is a phrase used

to describe a situation where a programmer

lets performance considerations affect the

design ofa pieceof code.This can result in

adesignthat isnotascleanasitcouldhave

been or code that is incorrect, because the

code is complicated by the optimization and

the programmer is distracted by optimizing.

Sometimes, early optimisation over-

throws benefits and can destroy the proj-

ect core with sloppy or dangerous code.

Optimisation is a subject many developers

overlook,whichisafatalmistakeintheindus-

try,especiallyonthegamedevelopmentside.

Peoplethinkduetothefactthattechnologyis

dailybecomingmoreandmorepowerful,code

andotheroptimisationisnotreallysomething

thatisnecessaryinprojects,buttheyforgetthe

mainpointwhich theythemselveswould look

atwhenevaluatingaproductorsolution:which

one isfaster?If the nextcreatorof the same

solution was marketing it as faster, whose

solution would you pick up off the shelf?

Optimisationdoesnotcomewithoutcosts,as

it isusuallymoredifficulttomaintainan opti-mised program than an unoptimised one, as

manyoptimisationssacrificemaintainabilityfor

speed,orresources.Whenyouoptimiseeach

pieceofcode,youneedtobeawareofafew

things of importance.After I haveoptimised

a piece of code, I must go back and check

the correctness, where sometimes the code

will cause incorrect output. Also, you should

measuretheperformanceandcompareitwith

thatbefore theoptimisation.Often enough, it

will be slower due to compiler optimisations

which you cancelled out, or other less obvi-

ouschangesinthecompilationandexecution

stages.OnceIhavesorteditoutandthereis

anincrease,Imaychecktheperformanceac-

cording to thegoal setout, andstop optimis-

ingso I dont changeanythingunnecessarily.

Theres a few simple tactics tooptimise your

codeand not have torun throughahundred

thousandlinesofcodesearchingforbottlenecks.

Takethesestepspracticallyinyourcurrent/next

projectandnoticehowlittletimeisspentonop-

timisingsmall areas of codepost-completion.

Optimisationhappensduringcodingaswellas

design. Ifyou are inclinedtowardsspeed, it

becomesamajorpartofthecodingstage.Be-

low,youwillreadthestrategiesIemploywhen

workingwitharelativelyslowactingprogram,

andtheseapplytoallcodestrategiesandmeth-

odsaswellasmostapplicationsofoptimisation

not only games. For example, I use these

commontechniqueswhenIworkonmobileap-

FOR A SPEED SURPRISE, GO

OPTIMISE!

TECH OPTIMUS PRIME?

DEV.MAG ISSUE 1622

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improve your code speed when employedaccurately and in context with the project.

Loop hoisting

Ifoundmyselfdoingthisalotinmycode,and

afterlearningabouttheinefficiency,itbecame

a habit toautomatically change it if I saw it,

or straight-up code it as I go. The idea be-

hind these loops is illustratedeasier through

code,andwithtimeandfocusyoucouldeas-

ilyusethefollowingtopreventuselessredun-

dancy. Below is anexample in pseudo-code.

for counter = 1 to 10

if (thisIsTrue) then

doThis(counter)

plicationsdue tothe limitedprocessorpower,whichgreatlyspeeduptimeonthedevice,and

onwebdevelopmentprojectswhereeffectively

managing code and resources means less

server-side overhead...less cost, less hassle.

Code efficiency

Creatingcodethat is fastAND portableAND

functional is a considerable task and takes

practice to be able to catch the dodgy code

in its tracks and fix the bottlenecks. Code

profilers are your friend run them and fil-

tertheresultsforanythingthatisslowerthan

itseemsit should be, thengo toyour source

andoptimise it.Thisis where the techniques

and ideas behind optimisation can greatly

else doThat

end if

Lets analyse this code ourselves. The loop

runstentimescheckingacertainvalue.You

maynoticethatthecodeisinefficientbecause

EVERYloopithastobreakoffintoconditional

statements,whichisusingupCPUpower,as

wellastheCPUtryingtoguesslogicaloutput

whichifiswrong(+-50%ofthetime)itneeds

tobacktracktocarryonwiththerightinstruc-

tionandreloadit.Thissimpleproblemlooksnot

sointense,untilitisbeingusedtopollortest

everyframeofagame,andaimingforhigher

framerateswillresultinevenmorework.Lets

lookatthenewcode,whichusesloophoisting

asaneffectivemeansto releasebottlenecks.

TECH OPTIMUS PRIME?

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timespenton thearray.Thesesituationsarecommonbutoftenunnoticedanddiscardedbe-

causemorearrayspacemaybeneeded,which

againthesedaysseemsmoreorlessirrelevant.

Profiling and disassembling

Runningprofilingprogramson yourcode can

give you a large amount of feedback. This

will help you pinpointvariousissues incode,

and effectively eliminate the problem areas.

Findingtheareaof problemis one thing, op-

timising it is another. Another strategy I use

is to disassemble the compiled code, which

gives you the assembler representation of

yourcode.Ifyouknoworlearnassembler,it

helps youeasily seewasted instructions and

findbetterways of removingredundant code.

Data management

Please, believe me when I say this: data is

themostoftenoverlookedbottleneck.Itslows

down almost every part of an application if

implementedbadly.Lookingatrevisingadata

moduleofsortscouldbeaheftytask,butweigh

uphowmuchitwouldbeworthitifyourdata

waswell-placed,alwaysreadytobeused,and

alwaysefficientlynothoggingupmemory.The

projectsstylesalwayshavesomerestrictionof

sorts, andsomeconceptofsorts, andalmost

alwaysusesadatasetupthatisbadlyimple-

mented due to the itsdata, it just needs to

betherewheni needit attitude.This,above

all else, can speed an application up by a

MASSIVEamount. Loadwhats needed, and

removeitwhenitsnot.Theresnopointinkeep-

ing thedatainmemory iftheuserdecidesto

choose Quit tomenu. Theyreprobablynot

goingbackintothatsectionofdataandmemory

rightaway,sounloaditandloadwhatsneeded

next,insteadofhavingtounloaditagainwhilehe

isexpectingtoloadanewlevelordifferentsave

game.Datamanagementandeffectivelyusing

thedatawillbenefityouinanytypeofprogram.

if (thisIsTrue) then

for counter = 1 to 10

doThis(counter)

else doThat

end if

ThisisQUITEalargeimprovementitnowhan-

dlestheifstatementonceandonceonly,not

tentimeseveryframe.Whenitcomestocon-

trolling larger structures,nested loops canbe

hoistedtoavoidexcessiveuseoftheprocessor.

Data types and sizes

Backintheday,usingsmallerdatatypeswas

betterbecauseofcertainimpactson thesys-

tem and its processor. These days, we see

thatusingsmallervariablesisoftennotanis-

sueforthesizeofthematter,butmoreforthe

speed. If youre using smaller sizedintegers,

useONLYthatsizeinthatpieceofcodeorap-

plication. For example, using a small integer

value and a long or larger integer value re-

quires a conversionto differentsizes EVERY

time that code is used or accessed,wasting

timeawayinthecyclesoftheprocessor.This

has a largeimpact ontheprocessor inmore

intenseapplications,suchasthosewithimage

processing,videoencoding,largearrayusage

and many areas in gamemap management.

Thesetechniquesareespeciallyusefulwhenit

mightbethatextraun-lagstrategyyouneed.

Array sizes

Remember that working inside your proces-

sor is many instructions and commands all

usuallywhichworka lotmoreeffectivelywith

powersoftwo.Abasicunderstandingofwhat

happensinsidetheprocessorwillshowthatit

hastomakeextracalculationsfora3x4grid,

becauseitneedstousemultiplicationandother

meanstofindtheindexinthearray,whereas

asimple4x4gridwouldusebinaryshiftswhich

arealotfasterandmoreeffective,reducingthe

Function sizes

Ifyourfunctioncodeiscrossingboundariesas

innotdoingitsSPECIFICfunctionitisbeing

wastefullyimplemented.Ifyoucodeyourfunc-

tionseffectively,theprofilingwillbeahundred

timeseasier.Thisisbecauseithastofindthe

bottlenecksinthecode,andifyouhavetwenty

functions in one,the profiler (usuallyworking

onaper-functionprofile)willtellyouitsslower.

Parallel execution

AmdahlsLawstates,Parallelexecutionisthe

mostcommontechniqueforspeedinguplarge

applications,butitaloneisnotsufficientforall

cases.Inparticular,AmdahlsLawclaimsthat

theinherentlysequentialportionofaprogramis

thelimitingfactorofspeedimprovements.

Theseareverybasicandnotin-depth,butwill

get you started before you hit your favourite

search engine and find more information on

taking control of code and effectively speed-

ing up a system. Game development is an

important optimisation concern as the faster

aframecanbeprocessed,themorethatcan

bedoneinoneframe.Forexample,thishelps

when speeding up the code for drawing the

scenewill allowenough ofa speedincrease

tointroduceanotherinterestingeffectorphys-

icschangeinagameengine.Thisarticleisfar

fromcomplete,butissufficientinmyviewsto

takeyoutothelevelofunderstandingthatone

needstowatchoutforsomecommonpitfallsin

codepractices.Takethiswithapinchofsalt,

andignorewhatyoudontneedorlike!Enjoy!

FUZZYSPOON

TECH OPTIMUS PRIME?

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Astheendof2000approachedus,we

werealreadywellunderwaywithour

Xbox development of Chase. From

whatIremember,ittookuslessthanaweek

togetalmostallofthegameasitwasported

fromPCtoXbox,whichisaterrifictestament

to not only how comparable the basics of

Xboxdevelopment were to PC development,

butalsohowrobustandeasytousetheXbox

SDKwas,aswellas how good theirsupport

system was through not only their develop-

mentNewsgroups, butalso through theirpri-

vatetechniciansupport.Oncewehadfinished

getting the game up and running for Xbox,

webegan toperformvariousmajoroverhauls

onit inorder totakeadvantage ofthesupe-

riorhardwarethatwenowhadatourdisposal.

We startedby completely throwingoutallart

assetsthatwehadpreviouslycreatedandwent

aboutmakingallnewworlds,props,andvehi-

cleswithpolycountsthatapproachedbetween

5and10timeswhatwehadpreviouslybeenus-

ingforthePCversion.Wealsonowhadaccess

toguaranteedshadertechnology(nomorewor-

ryingaboutend-userspecs!),sowewereable

tostartincorporatingsomespecialeffectssuch

asbumpmapping,lightmapping,realtimecube-mapreflections,realtimeshadowsforobjects,

andobjectself-shadowing.Whilethisgraphical

overhaulwasbeingdone,additionalchangesto

thegameitselfwerebeingincorporated.Dave

added motorcyclephysics, completewith the

abilitytodowheelies,tothegamewhichnow

gaveusfourtypesofvehiclesthatwecoulduse

(standard fourwheel vehicles, three wheeled

vehicles, multi-body articulated vehicles, and

motorcycles). Pedestrian and traffic AI were

alsooverhauledinordertomakethembehave

smarter as well as more realistically, and a

dynamic replay systemwas addedwhich al-

lowedlevelstoberecordedandplayedback.

Unfortunately,allofthisexcitingstuffwasoffset

bymoreunsettlingeventswithinourteam,the

firstofwhichbeingMattswifemovingbackto

theUSinearly2001.Shewastiredofnotbeing

abletowork,duetothelackofaworkpermit,

and she alsowas startingto miss her family

backhome.Thisobviouslyputalotofstrainon

Mattashereallywantedtostayandfinishthe

developmentofChase,butintheend,hedid

theonlythingthathecoulddoandalsoreturned

totheUSsometimearoundAugustofthesame

year.DaveandStacihadababyboyearlyin

theyear,whichIthinkmadeStacimissherfam-

ilyevenmore,andasaresult,shealsomoved

backtotheUSwhenwewentoverseasforE3

THE HISTORY OF I-IMAGINE

Part 7: Enter the publisher

HISTORY WHERE IT ALL BEGAN

inMay.Asexpected,Davealsoleftusinorder

tobewithhiswifeandchildatthestartofJuly,

oncehehadcomebacktoSouthAfricanafter

E3inordertotieupsomelooseends.Luckily,

wewereabletofindtwoveryablereplacement

programmers forthem inChris andMattwho

alongwithathirdprogrammer,Andrew,helped

us to complete the development of Chase.

However,beforeDaveandMattwouldleaveus

tobereplacedbyChris,Matt,andAndrew,we

hadthesmallmatterofE32001topreparefor.

The lead up to E3 was was pretty exciting

forus aswewereaskedbyMicrosofttosub-

mit somevideo footageof Chaseforthemto

incorporate into their E3 promo video which

would be running on the big screen in the

middleoftheirstand.FromwhatIcanremem-

DEV.MAG ISSUE 1625

( Who? What? Where? If youre lost concerning I-Imagine, check out Dev.Mag Issue 10 for the start of this article series! )

8/14/2019 Dev.Mag - 16

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ber,I thinkthat theyendedupusingthreeor

fourclipsof thevideo footage,eachonerun-

ningforbetweenthreeandfivesecondsorso.

Itwas definitely quitean awesome feeling to

bestandingintheMicrosoftboothatE3whilewatching footageofyour gameuponthe big

screen!ButbeforeweevengottoLosAngeles

forE3,Ihadtoendurethecraziestcrunchof

mylife.Forthemostpart,thedeadlineleading

uptoE3wasrelativelynormal.Wehadsome

pretty goodstuff tobringwithus alreadydue

tothepre-E3deadlinethatwehadimposedon

ourselvesin ordertogetthevideofootage to

Microsoft,buttherewasoneimportantfeature

thatweneededtohaveworkingperfectlybefore

goingtoE3,andthatwasourreplaysystem.

Thesystemitselfwasbasicallyalistofinputs

from the player, whichwhen played back at

theirappropriatetime,wouldrecreateaprevi-

ousgameplayexperienceperfectly.However,

this means that the entire engine needs to

behave ina deterministicmanner, and ifany

codeis added thatgoes against thisphiloso-

phy,itwillcausethereplaysystemtocometoa

grindinghalt.Unfortunately,thisiswhatbegan

tohappentousthedaybeforewewere due

tofly toE3. Idont rememberthespecificsof

whatcausedthesystemtobreak,butIthinkit

wasanadditiontotheAIcodewhichwasus-

ingtherandomfunctioninwaysthatitwasnt

supposedto. I dohoweverrememberstaying

awake at my desk for 21 hours while Dave

worked his butt off trying to fix the problem.

Whatmade this crunchevenmore important

(andthereforestressful...)isthatDanhadleft

forE3adayearlierthanuswithoutsomuchas

asingleworkingcopyofthegame,soitwasup

tousinordertogeteverythinginorderbefore

welefttojoinhiminLA.Luckily,Davemanaged

tosortouttheissueataround7amthenextday

andweboardedtheplanetoLAwithawellput

togetherdemoofourgame.Lookingback,Ican

alwaysmanagetolaughaboutthesituation,but

atthetime,itwasinsanelystressfulandscary

forallofus.Unfortunately,yetagainallofthe

hard work that we put into the game before

headingtoE3didntpayoffforusaswewere

still unable to attract a publisher for Chase,

With yet another trade show gone past us

wherewewereunabletosignadealforChase,

wedecidedthatanotheroverhaulwasneeded

forthegameinordertogeteverythingtothe

level where we would be able to have pub-

lishers interestedin signingus.We yetagainthrewoutallofourworlds(Ibelievethatthere

were only threeat this time)andwent about

redesigning them to be even better look-

ing thanwe had indone uptonow.Wealso

decided that we needed to make the game

more than just A-to-B driving, and ended up

coming up with a challenging yet rewarding

systemforthegameplaytobebasedaround.

Attheendoftheday,ourdesirewastomake

thegamefuntoplaywhilelimitingthefrustration

factorasmuchaspossible.Wetooktohearta

lotofwhatwelearnedfromNoahFalsteinstime

withusanddecidedtofocusonrewardingthe

playerwhileatthesametimeremovingasmany

formsofpunishmentaspossible.Weachieved

thisbymakingeachlevelinthegamehavea

certainnumberofobjectivestocomplete,where

eachobjectivewasworthacertainnumberof

pointsintheplayerscareer.Onceanobjective

wascompleted ina particularmovie scene, it

wouldstaycompletedandtheplayerwouldre-


ceivethepointsforit.Aplayercouldthenreplay

the level, doing another take for the movie

sceneandfocusoncompletingobjectivesthat

hewasntabletoduringthepreviousattempt.

Thissystemallowedustomakeitthatmostlev-

elsactuallyrequiredthe player todomultiple

takesiftheywishedtocompletealloftheobjec-

tives,asitjustwasntpossibleforthemtocom-

pleteeachandeveryobjectiveinasingletake.

Thepointsthattheplayerreceivedwerenec-

essaryinordertounlockthenextscenesin

each movie, and ultimately the next movie

in the players career. This meant that the

player couldplaya levelandcomplete what-

ever objectives hewas able to, then as long

as they had earned enough points basedon

thecompleted objectives,theywould beable

to progress to the next scene in the movie.

This enabled us tolower the frustrationlevel

forplayerswhowerentnecessarilyhardcore

gamersandpossiblywouldntbeskillfulenough

tocompleteall objectivesfor eachand every

level.However,aplayermayonlycompletethe

bareminimumnumberobjectivesnecessaryto

progressforawhileandthenreachasceneor

movie that theywouldnthaveenough pointsto unlock. In these cases, the player could

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backtrackto aprevioussceneandattemptto

completeanyobjectivesthat still remained in

ordertoearnenoughpointstounlockthenext

sceneormovie.Inmostcases,playerswould

haveincreased theirskill level withthegame

comparedtowhattheyhadwhenattemptingtocompleteearlierscenes,soobjectivesinthese

scenesthatmayhavebeentoodifficultearlier

on,wouldnowbewithintheirabilitytocomplete.

Asmentioned,notonlydidthissystemreduce

theamountoffrustrationinourgamefornov-

ice to intermediate players, it provided play-

ers with a longer gaming experience without

feeling punished for failure, as in each take

theycouldfocusonachievinganobjectiveor

objectivesthat theyfeltwerewithintheirabil-

ity.Thisalsohad the beneficial sideeffectof

allowingour small development teamto only

havetobuildarelativelysmallnumberoflev-

els for the game, and then reusing some of

themtostagemorethanasinglemoviescene.

Ontopofcreatingbetterlookinggraphicsand

designing a more fun and interactive game-

playsystem,wealsofeltthatinordertomake

players feel as though they were involved in

aHollywood actionmoviethatwe needed to

havealotmoreactionhappeningaroundthem.

Inorder toachievethis,wewent aboutmak-

ing the game environments as interactive as

wepossibly could. The firstpartof doingthis

involved creating a more advanced vehicle

damage system thathadper-vertexdamage,

whichallowedustoblendbothvertexandtex-

turesbetweennormalanddamagedversions

of each vehicle in the game. We expanded

this system to allow us to have parts of the

vehicle detach and become interactive parts

oftheworld oncetheyhadsustained enough

damage.Thismeantthatbonnets,doors,and

evenroofswouldeventuallybreakoffoftheve-

hiclesoncetheyhadbeensufficientlybattered.

The second part of creating a more interac-

tiveworldwas forustomakeasmuchofthe

environment as possible tobedestroyable in

someway oranother.Wewereableto have

prettymucheveryobjectinthegamethatcould

be hit except for buildings (ie. fire hydrants,

lampposts, telephonebooths, etc.) damage-

able or destroyable in when interacted with.

This meant that all of these items either

swapped to damaged versions of them-

selves, or broke up into multiple pieces,

each one with their own physics (ie. a tele-

phone boothwould break into its four sides

plus the roof, a wooden fence sectionwould

breakupintoindividualplanksofwood,etc.),

Andon top ofthat,someobjectswouldeven

have their own added effects (ie. a fire hy-

drant would leave behind a shooting jet of

water thatwouldapplya forceto anyobjects

that hit it, including the players vehicle).


Whilewewerebusyimplementingallofthese

changes,wewerecontactedprettymuchoutof

thebluebyaproducerfromacompanycalled

BAM!.Theywererelativelynewtotheworldof

gamepublishingandtheywerelookingatadd-

ingtitles to theirXbox lineup.Theproducers

namewasJoeBoothandhelikedwhathesaw

inChase from our website, so hewanted to

comedowntoSouthAfricanandvisitusinor-

dertoseehowourstudiowassetup.Sosome

time inAugust 2001 I believe,Joemade his

waytotheI-Imagineofficeswherehewasmore

thanimpressedatwhathesaw.Notonlywas

hehappywiththedirectionthatthegamewas

takingandhowitlookedinperson,hewaseven

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moreimpressedwiththeteamthatwehadput

togetherandthetoolsandtechnologythatwe

haddevelopedasthebackboneofthecompany.

InthenextweekorsoafterJoehadreturnedto

theUK,wewerealreadyincontactwiththem

inregardstotheirinterestinpublishingChase.

We began to negotiate with them via phone

andemail,and thenheaded toECTS inLon-

donatthestartofSeptemberinordertowork

onthefinerdetails ofthepublishing deal.As

thedealwasnt100%guaranteedyet,wealso

metwithsomeotherpublisherswhilewewere

inLondon,butallofourfocusandenergywas

reallyspentongettingthedealwithBAM!done.

Bythetime thatwe leftECTS,whichwas to-

wardstheend ofthe firstweekofSeptember

2001, we were quite confident that the deal

wouldbefinalisedinthenextfewweeksorso.

However,onlyafewdaysafterwegotbackto

SouthAfrica,theunthinkablehappened.9/11.

Aseveryoneknows,thefinancialclimateimme-

diateaftertheeventsonSeptember11,2001

wasnotverystable.Therewerebigdropsinthe

stocksof virtuallyall companiesdue toworry

aboutthestateofworldaffairs,andBAM!wasnotanexception.DuetothestockpriceofBAM!

sufferingasitdid,theyunfortunatelyhadtopull

out ofnegotiationswithusforthe timebeing

astheyjustdidnthavethecapitalinorderto

publishChaseavailabletothemanymore.As

you can imagine,we were quiteupset about

thisturnofevents,butluckilytowardstheend

of the year, the stockmarkets stabilised and

BAM!wasonceagaininapositiontopublish

Chase,soJoeflewbackdowntoSouthAfrica

afterChristmasinordertomeetwithusandour

boardofdirectorsinordertofinalisethedeal.

Once the deal was completed, we were as-

signedaProducerbythenameofBarry.Atfirst,

Barryworkedwithusremotelyinordertoget

theproductionschedulefinalisedand towork

onthefinaldirectionthatthegamewouldtake.

Afewmonthsintotheschedule,hecamedown

toourofficesandstayedwithusforacouple

of weeks while he tested the game and we

allworked togetheron ideas forfinalisingthe

restofthegamelevels.Oncethiswasfinished

however,werealisedthatwewerebehindon

ourinitialtimeprojections,and thatwewould

not beable tomakeBAM!sdeadlineforhav-

ing the game to market. Unfortunately, this

datecouldnotchangeastheyhadalreadyan-

nouncedtheirfinancialprojectionsforthequar-

terinwhichthegamewasduetobereleased,

andtheydidnotwanttocauseunrestwiththeir

shareholders. So, Barry came back down to

SouthAfrica a shorttimelater and spentthe

nextfewmonthscrunchingwithusinorderto

notonlyhavetherestofthegamebuilt,butalso

gameplaybalancedandbugtestedsothatwe

wouldbebackontrackagain.Thisunfortunate-

lymeantthatwehadtodrop1scenefromeach

ofour4movies,soweendedupwith16differ-

entmoviescenes insteadof ourintended 20.

Evenwiththechangeofschedule,wemanaged

tocompletethegamearound thestartof Au-

gust2002,atwhichpointitwentintotheTRC

(TechnicalRequirementCertification) process

at Microsoft. It failed at least once, possibly

twice,butitwasfinallyapprovedforgoldstatus

aroundthemiddleofSeptember,andwasavail-

ableinstoresinNorthAmericanandEuropein

thelastweekofSeptember2002.Oncereviews

for Chase: Hollywood StuntDriver (asit was

nowknown)startedtocomein,weweresur-


prisedathowmixedtheywere.Thereseemed

tobejustaboutasmanypeoplescoringusat

80% and higher as therewere scoring usat

50%andlower.Ultimately,Ithinkthatthiswas

probably due to the pick-up-and-play design

thatwehadforthegame.Alotofpeoplefound

thegameveryfun,compelling,andaddictiveto

play,whileawholerangeofotherpeoplefound

thegametobetooeasy,bland,andrepetitive.

Afterallofthereviewswerefinallydone,weend-

edupaveragingaround65%orsoifyoulookat

Metacritic (http://www.metacritic.com/games/

platforms/xbx/chasehollywoodstuntdriver?q=c

hase) andGameRankings (http://www.gamer-

ankings.com/htmlpages2/518048.asp). While

wewerentvery happywith thelower scores,

wewerequiteproudofbeingable tomakea

gamethatalotofpeoplefoundtobefuntoplay,

whichafterallisprimarilywhatplayinggames

shouldbeabout.Asforhowwellthegamesold,

thelastsalesfiguresthatIwasmadeawareof

indicated that about175 000 units had been

soldworldwide.Thisisntatremendousamount

atall,butwewereprettyhappywithitconsid-

eringthatitwasourfirsttitle,thatBAM!didnt

spendverymuchmoneyonmarketing it,and

thatitwasavailableononlyasingleplatform.

Overall,wewereprettyhappywithhowthings

turnedoutwithChase:HollywoodStuntDriver.

Wemade alot ofmistakesand learneda lot

ofgood lessons.Welostalotof good,expe-

rienced employees, but wewere able tofind

manytalentedSouthAfricanswhowereready

tojumpinandtaketheirplace.Inadditiontothe

previousSouthAfricanswhowerehired,during

thefinalyearorsoofourdevelopmentofChase

wemangedtohireawholeslewofadditional

3DartistswithSteven,Louis,Corlen,Gary,and

Lee.Aroundthestartof 2001we alsobegan

toputtogetherateamtofocusondeveloping

titlesfortheGameboyAdvance.Toachievethis

wehiredanadditionalprogrammernamedDio-

rgotoworkwithDerek,andalsohiredMichael

andDominiqueas2Dartiststoworkalongside

Jeanine in developing the art for the game,

whosstorywillhavetowaituntilanothertime.

COOLHAND

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One day, you stumble into your

friendsroomandfindhimsittingin

thecornerwithaGameboyAdvance,

hunchedover itlikea guilty teenagercaught

reading Playboy except the hunch isnt in-

spiredbyguilt.Infact,yourfriendhasnteven

noticedyouenteringtheroom.Hescompletely

absorbed with the little machines electronic

antics.Youbegintowonderwhattheheckis

goingon.Afterall,thisfriendisnotagamer.

Not by a long shot. He doesnt even know

howtoplayQuake.Infact,youdbesurprised

if heeven knew that the game existed. Yet

there hes sitting, enthralled by a Gameboy.

Surprising,butcute.Thepoorbuggerstrying

todabbleinaworldhehasnoideaabout!At

thispoint, a strangepaternal instinctkicks in

(eitherthat,orasubconsciousurgetogolaughathim),soyougotoseehowhesdoingwith

his forayintogaming. Then comesthenext

surprise.

Oh,thisoldthing?Ivehaditforages,playit

everyday.

TurnsouthelovesGameboy.Healsoshows

youhiscollectionofbookmarkedwebgames,

puzzle titles andmiscellaneous gaming doo-

hickeys.Allthistime,hesbeengamingeven

morethanyouhad,andyouneverhadaclue.

YouvesatwithyourAAAtitlesandlarge-scale

LAN events for all that timewithout ahintof

whatlaybeyondyourownsmallgamingworl

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