NAME
        AreaEllipse -- add a ellipse to areainfo list for areafill.


    SYNOPSIS
        error = AreaEllipse( rp, cx,   cy,   a,    b    )
        d0                   a1  d0:16 d1:16 d2:16 d3:16

        long areaellipse( struct rastport *, short, short, short, short)

    FUNCTION
        Add an ellipse to the vector buffer. It will be draw when areaend() is
        called.

    INPUTS
        rp - pointer to a rastport structure
        cx - x coordinate of the centerpoint relative to the rastport.
        cy - y coordinate of the centerpoint relative to the rastport.
        a  - the horizontal radius of the ellipse (note: a must be > 0)
        b  - the vertical radius of the ellipse (note: b must be > 0)

    RESULT
        error - zero for success, or -1 if there is no space left in the
                vector list

    SEE ALSO
        areamove() areadraw() areacircle() initarea() areaend()
        graphics/rastport.h