Double Buffering: Difference between revisions

For example, a method that will work is: each window could consist of a double buffer (or a single buffer that is updated on a redraw/paint event), as well as a double buffer for the entire screen. That way each program can draw on its back buffer and send it its own front buffer when it has finished drawing (either swapping pointers or <code>memcpy</code>) as often as it wants (wrapping a lock around the back buffer), then when the GUI has detected the back buffer has changed, it copies the window's front buffer (locking it temporarily) into the screen's back buffer, then when the VBLANK fires the screen's back buffer is copied to the front buffer if the screen's back buffer has changed.

 

 

Each window manager usually has its own method. But like mentioned above, tearing is a relatively minor issue in most general GUI programs that can often be overlooked, since you will be dealing with text and images that won't be updating. Therefore, if the front buffer is in the middle of outputting to the monitor while copying the next frame to it, you might notice a slight flicker that lasts for all but 1 monitor refresh (which is no less than 1/60th of a second on most monitors).