When you create a presentation space, the drawing mode is set to draw. Your application can change this mode using GpiSetDrawingMode. The two additional drawing modes provided by the PM are retain (DM_RETAIN) and draw-and-retain (DM_DRAWANDRETAIN). Your application can determine which drawing mode is set by using GpiQueryDrawingMode.
The drawing mode that you select becomes current for the presentation space, and it can be changed any number of times. Select the appropriate drawing mode before creating a segment. The drawing mode affects the segment type.