DIRECTORYImagerMasks, ImagerBasic, ImagerBrick;ImagerHalftone: CEDAR DEFINITIONS ~ BEGINTransformation: TYPE ~ ImagerBasic.Transformation;PixelArray: TYPE ~ ImagerBasic.PixelArray;PixelBuffer: TYPE ~ ImagerBasic.PixelBuffer;Brick: TYPE ~ ImagerBrick.Brick;Mask: TYPE ~ ImagerMasks.Mask;DeviceBrick: TYPE ~ REF DeviceBrickRep;DeviceBrickRep: TYPE ~ RECORD [fMin, sMin: INTEGER,fPeriod: NAT,phase: NAT,seq: SEQUENCE sPeriod: NAT OF PixelBuffer];MakeDeviceBrick: PROC [brick: Brick, maxPixelValue: CARDINAL] RETURNS [d: DeviceBrick];Halftone: PROC [dest: Mask, mask: Mask, source: PixelArray, transformation: Transformation, deviceBrick: DeviceBrick];DotScreen: PROC [x, y: REAL] RETURNS [fvalue: REAL];LineScreen: PROC [x, y:REAL] RETURNS [fvalue: REAL];END.   ¤  ImagerHalftone.mesaMichael Plass, July 11, 1983 3:56 pmData typesOperationsThe tranformation takes PixelArray space to device space: [x y 1] T = [s f 1].ÊL  ˜ J™J™$J˜ šÏk	˜	Jšœ%˜%J˜—J˜ Jšœ˜)head2™
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