public OpenVRInputObservable(CVRSystem hmd)
{
this.hmd = hmd;
var eventLauncher = new OpenVREventLauncher(hmd);
InputEvents =
from evt in Observable.FromEventPattern<OpenVREventArgs>(eventLauncher, nameof(eventLauncher.OpenVREvent))
let evtType = evt.EventArgs.EventType
let data = evt.EventArgs.EventData
where ControllerEvents.Contains(evtType)
where evtType == EVREventType.VREvent_ButtonPress || evtType == EVREventType.VREvent_ButtonUnpress
select new OpenVRControllerInput(hmd, evt.EventArgs.DeviceIndex, evtType, data.controller);
}