xsegs : draws a set of unconnected segments
xrect : draws a single rectangle
xfrect : fills a single rectangle
xrects : fills or draws a set of rectangles
xpoly : draws a polyline
xpolys : draws a set of polylines
xfpoly : fills a polygon
xfpolys : fills a set of polygons
xarrows : draws a set of unconnected arrows
xfrect : fills a single rectangle
xclea : erases a rectangle on a graphic window