Frame skipping with OpenGL and WinAPI?

Here is my situation. I'm creating a d开发者_JS百科rawing application using OpenGL and WinAPI. My OpenGL frame has scrollbars which renders the screen and modifies GlTranslatef when it gets a scroll message. The problem is wen I get too many shapes the scrollbar is less responsive since it cannot rerender it each and every time it gets a scroll message. How could I make it so the scrollbar has priority. I want it to skip drawing if it would compromise the smoothness of the scrolling. I thought of doing rendering on a separate thread but I was told all UI things should stay on the same thread. Thanks

You can measure the runtime of your draw routine. When it is greater than a threshold you decide, you should either throttle the updates or draw less (if you can).