The Gamepad Button Up Event.
This event is dispatched by a Gamepad instance when a button has been released on it.
Listen to this event from a Gamepad instance. Once way to get this is from the
pad2, etc properties on the Gamepad Plugin:
Note that you will not receive any Gamepad button events until the browser considers the Gamepad as being 'connected'.
You can also listen for an UP event from the Gamepad Plugin. See the
BUTTON_UP event for details.
The index of the button that was released.
The value of the button at the time it was released. Between 0 and 1. Some Gamepads have pressure-sensitive buttons.
A reference to the Button which was released.