PrimarySurface is a pointer to the primary surface.
__property TIvorySurface* PrimarySurface;
Description
The primary surface is a very special surface, because it represents the screen itself. It is strongly recommended not to draw on the primary surface. The best thing in DirectDraw is double buffering. This means you draw everything on the backbuffer surface, and then use the Flip method to copy the backbuffer to the screen. This technique prevents flickering, and makes your animations much smoother. So don't draw on the primary surface, unless you are absolutely sure what you're doing.