Hi all! I'm developing software for medical devices. I want to make perfect signal scrolling (like on oscillograph) using Open GL. Now our program has two threads: one for preparing bitmaps and other for rendering (program is very very old:-)). So question is how to render prepared bitmap more faster. Firstly I have used glDrawPixels/glCopyPixels functions (shift previous bitmap and draw new pixels columns). This method gave excellent result on most computers. But on some computers (especially with weak graphics) glCopyPixels doesn't work if my window is obscured by another. Can anyone tell me the best way to solve my problem using Open GL? Thanks.