
    <<PaintPMImpl.Mesa>>
<<Copyright © 1984 by Xerox Corporation.  All rights reserved.>>
    <<Last Edited by: Spreitzer, December 20, 1985 2:05:23 pm PST>>

    DIRECTORY Imager, ImagerColorOperator, ImagerOps, ImagerPixelMap, ImagerSample, ImagerTransformation, PaintPM, Rope;

    PaintPMImpl: CEDAR PROGRAM
        IMPORTS Imager, ImagerColorOperator, ImagerOps, ImagerPixelMap, ImagerTransformation
        EXPORTS PaintPM
        =
        {OPEN PaintPM;

        rasterToXY: ImagerTransformation.Transformation _ ImagerTransformation.Rotate[-90];

        PaintPixelMap: PUBLIC PROC [context: Context, pm: PixelMap, cm: ColorMap, clearValue: CARDINAL] = {
            mask: PixelMap = MakeMask[pm, clearValue];
            MapValueToColor: PROC [value: ImagerSample.Sample] RETURNS [cc: ConstantColor] = {
                cc _ cm[value];
                };
            Imager.SetSampledColor[
                context: context,
                pa: ImagerOps.PixelArrayFromPixelMaps[
                    pms: LIST[pm],
                    um: rasterToXY
                    ],
                colorOperator:  ImagerColorOperator.MapColorModel[
                    maxSampleValue: cm.length-1,
                    map: MapValueToColor]
                ];
            Imager.MaskBits[
                context: context,
                base: mask.refRep.pointer,
                wordsPerLine: mask.refRep.rast,
                sMin: mask.sMin,
                fMin: mask.fMin,
                sSize: mask.sSize,
                fSize: mask.fSize,
                tx: 0,
                ty: mask.sSize
                ];
            };

        opaque: CARDINAL _ 1;
        clear: CARDINAL _ 0;

        MakeMask: PROC [pm: PixelMap, clearValue: CARDINAL] RETURNS [mask: PixelMap] = {
            mask _ ImagerPixelMap.Create[
                lgBitsPerPixel: 0,
                bounds: [sMin: pm.sOrigin, fMin: pm.fOrigin, sSize: pm.sMin+pm.sSize, fSize: pm.fMin+pm.fSize]
                ];
            mask _ mask.SetWindow[pm.Window[]];
            FOR s: INTEGER IN [pm.sOrigin+pm.sMin .. pm.sOrigin+pm.sMin+pm.sSize) DO
                FOR f: INTEGER IN [pm.fOrigin+pm.fMin .. pm.fOrigin+pm.fMin+pm.fSize) DO
                    mask.PutPixel[s, f, IF pm.GetPixel[s, f]=clearValue THEN clear ELSE opaque];
                    ENDLOOP;
                ENDLOOP;
            pm _ pm;
            };

        }.