[RFC wayland-protocols] inputfd - direct input access protocol

[Bastien Nocera]

On Wed, 2017-04-05 at 10:42 +0100, Steven Newbury wrote:
> 
<snip>
> There's a reason the mouse support from the X DGA Extension out-
> survived the "direct framebuffer access".  The latency through the
> wire
> whether X or Wayland for mouse input it just too high for mouse
> controlled high framerate 3D games.  inputfd *will* be wanted for
> mice,
> and unlike keyboard there isn't the issue of state.

SDL2 doesn't use the DGA extension, which makes me think that it's not
as much of a problem as when running Doom in X in the 90's.

That being said, I see no reason why the compositor couldn't consider
the mouse to be a "gaming device" when a number of conditions are met,
such as the application being fullscreen, and the mouse having been
grabbed.

The compositor could then yank this device out of the application's
reach when unfullscreened, or the grab broken. Again, this is the
compositor's choice. And I'm certain that we'd extend most compositors
that way if game developers requested the functionality.