O Box 2390 Marrakesh Morocco Phone 212 24 43 46 49 Fax 212 24 43 74 09 lazrekatucamdotacdotma httpwwwucamacmafssmrydarab Abstract Justi64257cation of Latin script based texts is carried out by handling of hyphenation and insertion of interword glue w ID: 49303
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Arabictextjustication Figure3:PresenceofNoon-Meemligature(Source:HolyQuranwrit-tenbythecalligrapherAlhajHafezMohamedAminAlrochdi,scrutinizedandrevisedbyGeneralDirectorateofEndowments,Baghdad,p.649.) Figure4:AbsenceofNoon-Meemligature Š ,) ++&Figure5:Contextualandaesthetictransformations Beyondthesesizes,thesystemwillchoosecurvilin-earprimitiveandlinearfragments.Ofcourse,thiswillviolatethecurvilinearshapeoflettersandsym-bolscomposedatlargesizes[ 3 , 9 , 10 ].Abetterapproachconsistsofbuildingady-namicfont[ 4 , 7 ],throughparameterizationsofthecompositionprocedureofeachletter.Theintro-ducedparametersindicatetheextensibilitysizeordegree.Tohandletheelongations,aletterisdecom-posedintotwoparts:thestaticbodyoftheletterandthedynamicpart,capableofstretching.2.3LigaturesThecursivenatureofArabicwritingimplies,amongotherthings,awideuseofligatures[ 5 ].Indeed,Arabicwritingisrichinligatures.Someligaturesaremandatoryandobeygrammaticalandcontex-tualrules[ 5 ].Othersareoptionalandexistonlyforaestheticreasons,legibilityand/orjustication.Moreover,theconnectionofletters,inthecourseofwritingcursively,canleadtotheintroductionofimplicitcontextualligatures.Anexplicitligatureisthefusionoftwo,three,orevenmore,graphemes.Someaestheticligaturesresultinsomeread-ingambiguity.So,precisetextssuchastheHolyQuranaresometimeswrittenwithoutsuchligatures.Figure 3 showsanexampleofsuchambiguity:theNoon-Meemligaturecanbeconfusedwiththeini-tialformoftheletterGhain.Figure 4 showsthetextwithouttheligature.Generally,theligaturewidthisshorterthanthewidthofthefusedgraphemegroup.Forexample,theaestheticligatureŠinFigure 5 is9.65031ptwide,whereastheligaturegivenbysimplecontex-tualsubstitutions,)isratherwide(14.754pt).Thecontrolofligaturebehavior,bytheconver- dmh2 - dm$ �++c+#+c d# . Figure6:Variouslevelsofligatures sionofimplicitligaturesintoaestheticones,bringssome exibilitytotheword.So,itcanbeadaptedtotheavailablespaceontheline.TheexampleinFig-ure 6 showsthreeligaturelevels:mandatorysimplesubstitutions,aestheticligaturesofseconddegree,andnally,aestheticligaturesofthirddegree.Thetwolastligaturelevelsprovideshrinkingpossibilitiesofthesameword.Theuseofaestheticligaturesofsecondandthirddegreehastotakeintoconsiderationthecon-straintsoflegibility.Atypesettingsystemshouldtakeintoaccountthreelevelsofrecoursetoligatures.Intherstlevel,thereareonlyimplicitcontextualligaturesandmandatorygrammaticalligaturesofseconddegree.Thislevelisrecommendedfortextbookcomposi-tion,whereitisnecessarytoavoidanycollisionbe-tweencharactersand/oranyreadingambiguity.Inasecondlevel,someaestheticligaturesofseconddegreecanbeused.Thislevelisrecommendedforcompositionofbooksforthegeneralpublic.Thethirdlevel,wheretheuseofaestheticligaturesofhigherdegreesisallowedandlibertiesingraphicex-pressionscanbetaken,ispossibleinspecialcircum-stances.Theuse(ornot)oftheexplicitligaturestoim-provethejusticationshouldtakeintoaccountthegraphicenvironmentandtheblockregularityoftheconcernedtext.Incalligraphy,whenanaestheticligatureisused,thereisnoobligationtousethisligatureinalltextoccurrences.Thejusticationproblemcanberesolvedbytheuseofkashidasinatextcontainingonlyimplicitligatures.TheuseofligaturestojustifylinesisnotsolelyanArabicwritingcharacteristic.AdolfWild[ 12 ],theGutenbergmuseumconservatorinMainz,exam-inedtheGutenbergBiblefromatypographicalpointofview.Attheleveloflines,justicationwasmadevialigatures,insteadoftoday'svariablespaces.2.4OtherpracticesThebaseline(satralkitabah)isthelineonwhichlet-tersstandtoformwordsandthereforephrases.InArabicwriting,thebaselineisavirtualline.Thecharactersaswellasthewordsdonotstaydirectly TUGboat,Volume27(2006),No.2|Proceedingsofthe2006AnnualMeeting139 MohamedJamalEddineBenatia,MohamedElyaakoubiandAzzeddineLazrek Figure7:Kursyinta`lyqstyle(Source:Badai`AlkhatAl`arabi,p.372,NajiZineEddineAlmasref) onastaticlinewithaxedreference.Theletters owinaninteractivewaywiththesurroundinglet-ters.Theychangenotonlytheirshape,butalsotheirpositionwithrespecttoanimaginarybaseline.Lettersaswellaswordsarefreefromanyabsolutereference.Thereby,thelettersaswellasthewordsmaybetangled.AccordingtoIbnMuqlah[ 1 ],goodcompositionimpliesthreetypesofinteractingforcesamonglettersandwords: tarsif,thejunctionoftheconjointletters,whereeachletterseeksthepointofjoinwiththepre-cedingletter; ta'lif,theadditionoflettersinisolatedform,wheretheisolatedletterseekstolltheblankleftbythetypefaceoftheirneighboringletters; tastir,thewords'ruling,sothattheyareheldhorizontally.Fromanotherstandpoint,positioningvariationsoflettersandwordsareattheoriginofthechairskursy-s[ 2 ]theory,thatintroducesanumberofbear-inglines.Accordingtodi erentversionsofthisthe-ory,thenumberoftheselinescanvaryfromtwotove,orevensevenlines.Theheightsbetweenlinesvaryaccordingtoauthorsofthistheoryandcannotberespectedinpractice.Apparently,thistheoryisusedmoreinstyleta`lyq,asinFigure 7 .Thereby,wecanwondertowhatextentwecanformalizethisconceptforapossibleautomationthereof.Nevertheless,wecansaythatforjustication,calligraphersdousethetanglingpossibilitiesoflet-tersandwords,asinFigure 8 ,andinter-wordspaceshorteningasadditionaloralternativemethodsin-steadofkashidas.ThesametextwaswrittenbytwocalligraphersandwonaprizeintheIRCICA 1 2004competition.ThecompositioninFigure 9 byM.T.Alubaidyusedmorespacingandentangle- 1 http://www.ircica.org/ Figure8:Wordstangle Figure9:Justicationfavoringtheuseofincreasingspaces Figure10:Justicationfavoringtheuseofkashida ment,whileA.AlabdoinFigure 10 favoredmorekashida.Calligraphersalsobuildonotherpracticesforjustication,suchas: wordheaping;thisconsistsofputtingcertainwordsaboveothers|especially,thewordAllahabovetheprecedingword(seetheendoftheseventhlineofFigure 11 ); 140TUGboat,Volume27(2006),No.2|Proceedingsofthe2006AnnualMeeting Arabictextjustication Figure11:Heapingwordsandhyphenatingfragments Figure12:Wordhyphenation movingthebrokenfragmentabovethehyphen-atedword,asinthelastwordofthefourthlineinFigure 11 ; wordhyphenation,asinFigure 12 ; wordhyphenationinmargin;thisisanexpul-sionofhyphenatedfragmentstotheline'smar-gin,insteadofthefollowingline,asinFig-ure 13 ; decreasingofsomewordsattheendofaline,asinFigures 14 and 15 ; curvingofthebaseline,asinFigure 16 .Sincethe10thcentury,hyphenationsatendsoflineshavebeenstrictlyprohibited.Thiswasprob-ablyduetothecursivestructureoftheArabiclan-guage,andtothepossibleabsenceofvocalizationsigns.Thereareevensentenceswhichitisadvisednottohyphenate(ex.sallaALLAHelyhwsallam).IfwordhyphenationwasacceptedinArabic,legibil-itywouldbeconsiderablya ected.Nowadays,onlythefamouscaesuraathem-stitchboundaryisallowed.Regardedasapause, Figure13:Expulsioninmarginofhyphenatedfrag-ment(Source:HolyQuranwrittenbyYakoutAlmusta`simywithstyleRyhanyandKufyinIranmuseum) Figure14:Decreasingofwordsatendofline Figure15:Decreasingofwordsatendofline(Source:Badai`AlkhatAl`arabi,p.372,NajiZineEddineAlmasref) Figure16:Curvingofthebaseline TUGboat,Volume27(2006),No.2|Proceedingsofthe2006AnnualMeeting141 MohamedJamalEddineBenatia,MohamedElyaakoubiandAzzeddineLazrek Figure17:Caesuraathemstitchboundary Figure18:StretchingLam Figure19:SimpleLam thisdoesnota ectlegibilitysincethehyphenatedwordisstillheldonthesameline,asshowninFig-ure 17 .Thereisalsoastretchingletter,showninFigure 18 ,whichisnotallowedanymore,Figure 19 .2.5Diacritic/metricdotTheqalamusedtoproducethecalligraphicstyleNaskhisapieceofreedlikea utemouthpiece,showninFigure 20 .Thereed'sheadshapecorre-spondstothegraphicstylethattheqalamorfeatherwillo er.Forexample,intheNaskhstyletheshapeisbeveled,andintheMaghrebystyleitispointed.Thefeather'sheadinNaskhstyleisa atrectangle.Duringtheoperationofwriting,ithastobemain-tainedwithaninclinationangleofapproximately70withavirtualbaseline.Thediacriticdotwhichappearsasatiltedsquareisthetypographicalunitmarkedbythe Figure20:QalamofArabiccalligraphy Figure21:Diacriticdotspositioning(Source:HolyQuranwrittenbythecalligrapherAlhajHafezMohamedAminAlrochdi,ScrutinizedandrevisedbyGeneralDirectorateofEndowments,Baghdad,p.43.) fg=[]f'# g=[ ]f-+g=[+]f1/g=[/]f73g=[3]f?;g=[;]fGCg=[C]fOKg=[K]frhg=[] Figure22:Letterclusters featherinuse.Thesystemofdiacriticdotsplaysaleadingse-manticrole.Indeed,certainlettersarecharacterizedbythepresence,numberandpositionsofdots.Thebasicglyphxgivesrisetoseverallettersaccord-ingtothenumberofdiacriticdotswhichappearaboveorbelow:,,and.Similarly,theglyph#provokesseverallettersaccordingtopres-enceandpositionofthedotwithrespecttothebasicglyph:#,'and (notedas[ ]inFigure 22 ).Inthecaseofasuccessionofletterscarryingtwodi-acriticdots,thedotsmayinterferewitheachother.Theycanthusbeplacedhorizontallyonenexttotheother,orverticallyoneabovetheother,accordingtotheavailablespaceaboveorbelowthebasicglyph,asinFigure 21 ,or|evenbetter|tostretchlettersforbetterspacing.Moreover,accordingtothestyle,thesizeofthediacriticsignalsochangesaccordingtothestretchingsize,alsoseeninFigure 21 .Theimportanceofthediacriticdotgoesbe-yonditsphoneticrole.Thisdotisalsothemea-sureunitusedforregularizingthedimensionsandthemetricsofglyphs.IbnMuqlah 2 speciedlet-termeasurementsinmetricdots.Inordertogive 2AbouAliBenMohamedBenAlibnouMuqlat[272{328A.H./886{940A.D.],anativeofShirazandaministeroftheAbbasidcaliphinBaghdad,wasoneofthersttheoristsofArabiccalligraphy.Hiscontributiontothisartwasnottheinventionofanewscriptbuttheapplicationofsystematicrulesthatdeterminethesurfaceareaandproportionsoftheindividualletter-shapeswithrespecttooneanother. 142TUGboat,Volume27(2006),No.2|Proceedingsofthe2006AnnualMeeting Arabictextjustication Figure23:ArabicletterAlefmetrics homogeneitytoletters,heincludesalltheArabiclettersinacircleofsixdotsdiameter,theAleflet-terheight.Figure 23 showsthemetricoftheArabicletterAlefinmetricdot.Ofcourse,thisnotionre-mainsrelativeandapproximate;thedotpositioninthelineandthepositionofdotsamongthemleadtodi erencesamongcalligraphers.2.6AllographsTheallographsarethevariousshapesthatalettercantakewhilekeepingitsplaceintheword:iso-lated,initial,medianornal.Letterscanhaveaddi-tionalshapeseventhough,grammatically,thereareonlyfourshapes.Allometryisthenthestudyofallo-graphs:shape,position,context,etc.Generally,theelectionofanallographrespondstoaestheticneeds.So,thischoiceislefttothewriter.However,theuseofanallographissometimesdesiredandevenrecommended.Theletter'sshapeshouldchangeac-cordingtothelettersintheneighborhoodand,insomecases,accordingtothepresenceofkashida.Someexamples: themedianformoftheletterBehshouldtakeamoreacuteshapeifitinterposestwospineletters: theinitialformofBehcantakethreeallographshapes,accordingtoitsfollowingletter: theinitialformoftheletterHahmaytaketheshapeoflawziHahwheneveritprecedesanas-cendingletter: theinitialformoftheletterAinshouldtaketheshapeofnjaniAinwhenitisfollowedbyanascendingletter: theinitialformoftheletterHahaswellasthenalformoftheletterMeemchangetheirmor-phologicalformsinthepresenceofkashida: theletterKafchangesitsmorphologicalshapeinthecaseofstretchingandshouldbechangedintozinadiKaf: 3PropositionforArabicjusticationAswehaveseen,toperformtextjustication,Ara-bicwritingprovidesvarioustechniquescomingfromitshandwritingtraditions.Thesetechniquesarenotbasedontheinsertionofvariablespacesbetweenwords.So,unpleasantspacesareavoidedandabal-ancedaspectcanresult.Thepresentstudywillberestrictedtoafor-malismoftheproblemoftextjusticationinthecalligraphicstyleNaskh.Forreasonsoflegibility,theNaskhstylehasbeenadoptedintypesettingsincetherstattemptsofcomputerizationandstan-dardizationofArabictypography.TheNaskhstylestandsbetweenthedicultThuluthstyleandeasyRuq`astyle.OurchoicefortheNaskhstyleisalsomotivatedbythefactthatsomecalligraphicstyles,suchastheRuq`astyle,donotallowtheuseofkashida.Otherstyles,suchasthekustyle,haveageometricalstructurewhichgoesbeyondtherulesoffeatherandmetricdot,whilestillotherstylesuselettersstretchingonlyforaestheticpurposes.Ontheotherhand,theNasta`liqandDiwanistylesaremoregenerouswithnumberofkashidas:awordofthreeletterscanindeedreceivetwoelongations.3.1BreakingaparagraphintolinesBeforeusingligaturesorkashidatojustifylines,asystemhastorstbreakparagraphsintolines.Alegitimateplacetobreakasequenceofwordsintolinesisapositioninaplacethatgivesagoodlength.Therefore,itmaybetheborderofthelastwordofahorizontallistwhichgeneratesawidthequaltoorlessthanthevalueofthelinewidth.Ortheborderofthelastwordofahorizontallistwhichgenerates TUGboat,Volume27(2006),No.2|Proceedingsofthe2006AnnualMeeting143