NAME
        ReadPixelLine8 -- read the pen number value of a horizontal line
        of pixels starting at a specified x,y location and continuing
        right for count pixels. (V36)

   SYNOPSIS
        count = ReadPixelLine8(rp,xstart,ystart,width,array,temprp)
        D0                     A0 D0:16  D1:16  D2    A2    A1

        long readpixelline8(struct rastport *, uword, uword, uword,
             ubyte *, struct rastport * );

   FUNCTION
        For each pixel in a rectangular region, combine the bits from each
        of the bit-planes used to describe a particular rastport into the pen
        number selector which that bit combination normally forms for the
        system hardware selection of pixel color.

   INPUTS
        rp    - pointer to a rastport structure
        (x,y) - a point in the rastport
        width - count of horizontal pixels to read
        array - pointer to an array of UBYTEs from which to fetch the pixel data
                allocate at least (((width+15)>>4)<<4) bytes.
        temprp - temporary rastport (copy of rp with layer set == null,
                 temporary memory allocated for
                 temprp->BitMap with Rows set == 1,
                 temprp->BytesPerRow == (((width+15)>>4)<<1),
                 and temporary memory allocated for
                 temprp->BitMap->Planes[])

   RESULT
        For each pixel in the array:
            Pen - (0..255) number at that position is returned
        count   - the number of pixels read.

   NOTE
        width must be non negative

   BUGS

   SEE ALSO
        readpixel()  graphics/rastport.h