
<<ImagerDitheredDevicePrivate.mesa>>
    <<Copyright © 1985 by Xerox Corporation.  All rights reserved.>>
    <<Michael Plass, June 25, 1985 2:03:24 pm PDT>>
    <<>>
    <<Private interface for the benefit of ImagerOps.>>
        <<>>
    DIRECTORY
        ImagerColorDefs USING [SampledColor],
        ImagerDitheredDevice USING [MapEntries],
        ImagerDither USING [PackedColorDesc, Table],
        ImagerPixelMap USING [PixelMap],
        ImagerSample USING [Sampler, SampleBuffer],
        ImagerTransformation USING [Transformation],
        PrincOps USING [BitBltFlags],
        Terminal USING [Virtual]
        ;

    ImagerDitheredDevicePrivate: CEDAR DEFINITIONS
    ~ BEGIN

        Case: TYPE ~ {nil, constant, stipple, rgb, sampled};

        StippleArray: TYPE ~ PACKED ARRAY [0..16) OF WORD;

        Data: TYPE ~ REF DataRep;
        DataRep: TYPE ~ RECORD[
            terminal: Terminal.Virtual _ NIL,
            frame: ImagerPixelMap.PixelMap,
            mapEntries: ImagerDitheredDevice.MapEntries _ NIL,
            table: ImagerDither.Table _ NIL,
            case: Case _ nil, -- what type of color
            zerosAreClear: BOOL _ FALSE, -- special case for sampled black clear.
            flags: PrincOps.BitBltFlags _ [], -- bitblt flags
            grayWord: WORD _ 0, -- bitblt gray word
            packedRGB: WORD _ 0, -- for case = rgb
            stipple: StippleArray _ ALL[0], -- stipple pattern
            fTileOrg: NAT _ 0,
            sTileOrg: NAT _ 0,
            sampledColor: ImagerColorDefs.SampledColor _ NIL, -- sampled color
            sampledColorData: SampledColorData _ NIL, -- cached data associated with sampledColor
            paToDevice: ImagerTransformation.Transformation _ NIL, -- transformation from pa coords to display
            sampBuffer: ImagerSample.SampleBuffer _, -- scan line buffer for samples
            lineBuffer: ImagerSample.SampleBuffer _, -- for ops that cannot go directly to frame
            sampler: ImagerSample.Sampler _, -- sampler information
            extras: REF _ NIL
            ];

        SampledColorData: TYPE ~ REF SampledColorDataRep;
        SampledColorDataRep: TYPE ~ RECORD [
            packing: ImagerDither.PackedColorDesc,
            source: ImagerPixelMap.PixelMap  -- 16 bits per pixel, packed RGB, with space for tile index.
            ];


    END.