module Touch:sig..end
Touch events are only reported whenever they occur
in the application surface (FIXME is that true ?).
Coordinates are in surface normalized
coordinates with (0,0) corresponding to the bottom left corner
and (1,1) to the top right corner.
type
val id : t -> intid t is a unique identifier for the touch
(FIXME across device identifiers ?)val did : t -> intdid t is a device identifier for the touch.val pos : t -> Gg.p2 React.signalpos t is the current touch position of t.val dpos : t -> Gg.v2 React.eventdpos t occurs when the touch moves with the current touch position
minus the previous one.val pressure : t -> float React.signalpressure t is the pressure normalized from 0. to 1. (if
available).val over : t -> [ `Cancel | `Up ] React.eventover t occurs once whenever the touch ends either because
the pressure stops (`Up) or because the touch is canceled (`Cancel,
for example if the touch is captured by something else).val start : t list React.eventstart occurs whenever touches do.