Touch sensor methods, devices and systems are disclosed. One embodiment of the present invention pertains to a method for reporting a sub-gesture on a touch sensing surface, e.g., laid over a display of a user interface device. The method comprises determining a number of fingers simultaneously placed on the touch sensing surface. The method also comprises periodically sampling respective position data of the fingers moving along the touch sensing surface and calculating event data based on the position data, wherein each of the event data includes a geometric shape associated with the number of fingers and a centroid of the geometric shape. The method further comprises forwarding the event data to a presentation layer of application of the user interface device, where the application is configured to identify a gesture based on a subset of the event data.