Hi Mike, On 25 November 2015 at 16:06, Mike Johnson <mikeyj...@hotmail.com> wrote: > I've created 2 buffers of the same size (800x600 pixels). So I want the > input buffer to get filled off-screen, while the output buffer will show the > content on-screen. > > First of all what sort of content could be used to illustrate this > technique, and secondly, what mechanisms are available to: > > a) Notify that the input buffer is full > b) Copy the content to the output buffer so that it shows on-screen
It's quite simple. wl_surface_attach(surf, buf) + wl_surface_commit(surf) will display 'buf' for that surface. At that point, the compositor owns that buffer, so you should stop drawing on it. When the compositor has finished with a buffer, it will send you a wl_buffer.release event. You can sync your paint clock to the compositor's repaint loop with wl_surface_frame. So, the normal workflow is: - create surface S, buffer A, buffer B - draw first frame into buffer A - call wl_surface_frame(S) + wl_surface_attach(S, A) + wl_surface_commit(S) + wl_display_flush() - go to sleep - receive completion for wl_surface_frame callback - draw second frame into buffer B - call wl_surface_frame(S) + wl_surface_attach(S, B) + wl_surface_commit(S) + wl_display_flush() - compositor now owns both buffers, so don't touch any - receive wl_buffer.release event for buffer A - now unused - receive completion for wl_surface_frame callback - draw third frame into buffer A - ... Hope that helps. You can see the weston-simple-shm client for a pretty straightforward example. Cheers, Daniel _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
