Do any operating systems expose mixed buffering (for real screen rendering) to applications? I know Windows used to allow full-screen apps to implement single buffering, but I don't know if it could seamlessly transition into double buffering.
drawing-buffer (single) [user copies to] -> commit-buffer ---------------------------------- [system copies to] -> screen
alternatively
drawing-buffer (double) [user swaps to] -> commit-buffer ---------------------------------- [system copies to] -> screen
etc.