NAME
        ReadPixelArray8 -- read the pen number value of a rectangular array
        of pixels starting at a specified x,y location and continuing
        through to another x,y location within a certain rastport. (v36)

   SYNOPSIS
        count = ReadPixelArray8(rp,xstart,ystart,xstop,ystop,array,temprp)
        D0                      A0 D0:16  D1:16  D2:16 D3:16 A2    A1

     long readpixelarray8(struct  rastport *, uword, 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
        (xstart,ystart) - starting point in the rastport
        (xstop,ystop)   - stopping point in the rastport
        array - pointer to an array of UBYTEs from which to fetch the pixel data
                allocate at least ((((width+15)>>4)<<4)*(ystop-ystart+1)) 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
        xstop must be >= xstart
        ystop must be >= ystart

   BUGS

   SEE ALSO
        readpixel()  readpixelline8()  graphics/rastport.h