Framerate drop on mousemove in fullscreen mode / Ubuntu 16.04 LTS

Hi fellows,
i recently installed a fresh Ubuntu 16.04 LTS x64 on a i3 / 8GB / Intel 620 machine.
My overall plan is to have 2 screens and a application expanding over both in fullscreen.
I had to compile poco myself.

My first approach was an application running in OF_FULLSCREEN, which did their job nicely unless i move the mouse. When moving the mouse once, the framerate drops, the mouse is getting laggy, i can’t even quit the application with keyboard commands.

  • my event handlers are empty
  • when stopping the mouse movement again, the problem persists for the runtime of the application
  • clicking without moving the mouse doesn’t affect performance
  • also when starting as OF_WINDOW and expanding the window over both screens works fine.

My board research pointed out some vsync problems on linux/fullscreen. But these didn’t lead to a solution.
I guess it’s something pointing towards some window-management, event-polling related stuff.

Hacky solution:
I installed compiz and bundled the 2 screens to one big screen (i’m lucky: they have the same height :cold_sweat: ). When starting my application now, everything runs as expected.

Maybe related:
https://github.com/openframeworks/openFrameworks/issues/5009

Perhaps a linux-guru could give this a look…
Happy coding! :vulcan: