
    <<ImagerDevice.mesa>>
        <<Copyright © 1984, 1985, 1986 by Xerox Corporation.  All rights reserved.>>
        <<Michael Plass, June 11, 1985 2:50:25 pm PDT>>
        <<Doug Wyatt, March 6, 1986 9:27:16 pm PST>>

    DIRECTORY
        ImagerColor USING [Color],
        ImagerFont USING [CorrectionType, XChar],
        ImagerSample USING [BoxAction, BoxGenerator, SampleMap],
        ImagerTransformation USING [Transformation],
        Scaled USING [Value],
        SF USING [Box, Vec],
        Vector2 USING [VEC];

    ImagerDevice: CEDAR DEFINITIONS
    ~ BEGIN

        Transformation: TYPE ~ ImagerTransformation.Transformation;
        Vec: TYPE ~ SF.Vec;
        Box: TYPE ~ SF.Box;
        BoxAction: TYPE ~ ImagerSample.BoxAction;
        BoxGenerator: TYPE ~ ImagerSample.BoxGenerator;
        SampleMap: TYPE ~ ImagerSample.SampleMap;
        Color: TYPE ~ ImagerColor.Color;

    HalftoneParameters: TYPE ~ RECORD[
        dotsPerInch: REAL,
        angle: REAL, -- degrees anticlockwise from +x axis
        shape: REAL -- 0.5 is circular
        ];

    Device: TYPE ~ REF DeviceRep;
    DeviceRep: TYPE ~ RECORD[
        class: DeviceClass, -- class operations
        data: REF, -- instance data
        box: Box, -- bounding rectangle, in device coordinates
        surfaceToDevice: Transformation, -- transformation from surface to device coordinates
        surfaceUnitsPerInch: Vector2.VEC, -- x and y scale factors
        surfaceUnitsPerPixel: NAT -- surface resolution may be a multiple of pixel resolution
        ];

    CharMask: TYPE ~ REF CharMaskRep;
    CharMaskRep: TYPE ~ MACHINE DEPENDENT RECORD [
        font: REF, -- font and char together provide a unique identifier for this mask
        char: ImagerFont.XChar,
        sEscapement, fEscapement: Scaled.Value,
        sMinBB, fMinBB: INTEGER,
        sSizeBB, fSizeBB: CARDINAL,
        metricsValid: BOOL, -- numbers above are invalid if this is true.
        amplified: BOOL,
        correction: ImagerFont.CorrectionType,
        flag: PACKED ARRAY [0..10) OF [0..1], -- for padding and expansion
    data: SELECT rep: * FROM
        raster => [bits: SEQUENCE COMPUTED CARDINAL -- sSize*Ceiling[fSize/16.0] -- OF WORD],
        runs => [run: SEQUENCE nRuns: CARDINAL OF Run],
        uncached => [],
        ENDCASE
        ];

    Run: TYPE ~ MACHINE DEPENDENT RECORD [fMin: CARDINAL, lastRun: BOOL, fSize: NAT];
        <<Same as PDFileFormat.Run; fMin is relative to fMinBB.>>


    SetColorProc: TYPE ~ PROC [self: Device, color: Color, viewToDevice: Transformation];
    SetPriorityProc: TYPE ~ PROC [self: Device, priorityImportant: BOOL];
    SetHalftoneProc: TYPE ~ PROC [self: Device, halftone: HalftoneParameters];
    MaskBoxesProc: TYPE ~ PROC [self: Device, boxes: BoxGenerator, bounds: Box];
    MaskBitsProc: TYPE ~ PROC [self: Device, boxes: BoxGenerator, bounds: Box, 
    src: SampleMap, offset: Vec];
    MoveBoxesProc: TYPE ~ PROC [self: Device, boxes: BoxGenerator, bounds: Box, offset: Vec];
    MaskCharProc: TYPE ~ PROC [self: Device, mask: CharMask, offset: Vec];
    DoWithBufferProc: TYPE ~ PROC [self: Device, action: PROC, bounds: Box];

    DeviceClass: TYPE ~ REF DeviceClassRep;
    DeviceClassRep: TYPE ~ RECORD [
        type: ATOM,
        SetColor: SetColorProc,
        SetPriority: SetPriorityProc,
        SetHalftone: SetHalftoneProc,
        MaskBoxes: MaskBoxesProc,
        MaskBits: MaskBitsProc,
        MoveBoxes: MoveBoxesProc,
        MaskChar: MaskCharProc,
        DoWithBuffer: DoWithBufferProc
        ];


    NewClass: PROC [
        type: ATOM,
        SetColor: SetColorProc,
        SetPriority: SetPriorityProc _ NIL,
        SetHalftone: SetHalftoneProc _ NIL,
        MaskBoxes: MaskBoxesProc,
        MaskBits: MaskBitsProc _ NIL,
        MoveBoxes: MoveBoxesProc,
        MaskChar: MaskCharProc _ NIL
        ] RETURNS [DeviceClass];


    END.