% operand stack configuration in order to use psDrawFilled:
%		psFillwOL
%		XPoint[0].y
%		XPoint[0].x
%		n
%		...
%		XPoint[n].y
%		XPoint[n].x
%		graphics-context dictionary
% this draws lines connecting all the points and fills the
% region with background color (default: 1, or white).

/psFillwOutline
        {	gsave
                newpath
                yVal moveto
                1 sub {
                        yVal lineto
                } repeat
		closepath
		begin installGC
			gsave fill grestore	%% fills with foreground color
		0 setgray stroke grestore end }	%% outline it with black
        def