read-state-events.md

uid	input-system-read-state-events

Read state events

State events contain raw memory snapshots for Devices. As such, interpreting the data in the event requires knowledge about where and how individual state is stored for a given Device.

The easiest way to access state contained in a state event is to rely on the Device that the state is meant for. You can ask any Control to read its value from a given event rather than from its own internally stored state.

For example, the following code demonstrates how to read a value for Gamepad.leftStick from a state event targeted at a Gamepad.

InputSystem.onEvent +=
    (eventPtr, device) =>
    {
        // Ignore anything that isn't a state event.
        if (!eventPtr.IsA<StateEvent>() && !eventPtr.IsA<DeltaStateEvent>())
            return;

        var gamepad = device as Gamepad;
        if (gamepad == null)
        {
            // Event isn't for a gamepad or device ID is no longer valid.
            return;
        }

        var leftStickValue = gamepad.leftStick.ReadValueFromEvent(eventPtr);
    };