Is there any existing research on dealing with simultaneous gestures on a touchscreen device? More specifically, the challenges and issues with allowing more than one person to interact with a touchscreen device at the same time. Consider a scenario where a touchscreen is mounted between two people, and both try to use it at the same time, e.g. a vehicle's console.
It already seems that I'll have to implement my own gesture-detection library, since the existing libraries I've seen only deal with multi-touch, not simultaneous gestures that each involve multi-touch. (Although I would be happy to be wrong about that.)
At this point, my exploration of the topic is only at the preliminary stage, i.e. pondering the human-factors implications, and wondering if I'll really have to implement my own gesture-detection library just to be able to test the idea.