任意宽度直线的绘制与反走样

©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.()EngineeringJournalofWuhanUniversityVol.39No.4Aug.2006:2006203205:(19812),,,,.:(60573146).:167128844(2006)042130204,(,200030):,DDAWu,:x(y),y(x),,.,()..,.,.:;;DDA:TP391.72:AArbitrarywidthlinegenerationandanti2aliasingLIZhenxiao,HEYuanjun(DepartmentofComputerScienceandEngineering,ShanghaiJiaotongUniversity,Shanghai200030,China)Abstract:Itsusuallyadifficulttasktodrawaspecified2widthandanti2aliasinglineonarasterdispla2yer,duetoitsdiscretecharacterization.Thoughatriangle2paircansimulatealine,theanti2aliasingal2gorithmoftriangledoesnotensurethesmoothnessandstabilityofamovingline.Anovelmethodforspecified2widthanti2aliasinglineisproposed.Basedonlow2passfiltertheory,combinedwithdigitaldif2ferentialanalyzer(DDA)rasterizationalgorithmandWuanti2aliasinglinealgorithm,thenewmethodgetsagoodresultunderfairlycost.Keywords:linegeneration;anti2aliasing;DDA,(()),.,,.,.[15],Wu[6].DDA[7]Wu,,.11.1,,.,.y=f(x),:xy.x,x1,y©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.:(1).,,.,.(2).,,.,,,.(3).,.().Wu.22.1s(x,y),xy.D[m,n],mn(),(x,y)D.,S(,¢).D,,m,n.DDA,:0()1().,PH(,)=1,(,)P0,(,)|P,,.(m,n),,,.3,,.2.2,,.,.,(18)..,01,.H(,)=d,d[0,ColorDepth],(,)P0,(,)|P,ColorDepth.4,x,,.,,.Wu.131©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.()2006343,DDAWu,.3.15,,(1,1xy).:(1)yWy(5),Wyx,y.(2)DDA,x,,(6)..(1),,y,.(2)(3).3.2.7,x4,y,d1d2d3d44.di(4)Ii.Ii=max(0,min(1.0,0.53Wy-di+0.5)),,.,.3.3,(),di(8),3.2,di:Ii=max(0,min(1.0,0.5-di)),(),.,.,.[0,1],,.44.19,10.,.,,.,.Wu[6],Wu,,.[224],,,.4.21.xN,yM.x,M,O(M).x..O(MN).,x,,231©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.(N).5.DDAWu,,.,,,.:[1],,,.[J].,1997,43(1):1132118.[2],.[J].,2002,34(4):3912393.[3],,.[J].,2003,15(1):71275.[4],,.[J].,2003,35(2):1482151.[5]GrowF.Thealiasingproblemincomputer2generatedshadedimages[J].CommunicationoftheACM,1997,20(11):7992805.[6]WuX.Anefficientanti2aliasingtechnique[J].Com2puterGraphics,1991,25(4):1432152.[7],.[M].:,1995.331