Struct InputControlExtensions.InputEventControlEnumerator

Iterates over the controls in a StateEvent or DeltaStateEvent while optionally applying certain filtering criteria.

Namespace: UnityEngine.InputSystem
Syntax
public struct InputEventControlEnumerator : IEnumerator<InputControl>
Remarks

One problem with state events (that is, StateEvent and DeltaStateEvent) is that they contain raw blocks of memory which may contain state changes for arbitrary many controls on a device at the same time. Locating individual controls and determining which have changed state and how can thus be quite inefficient.

This helper aims to provide an easy and efficient way to iterate over controls relevant to a given state event. Instead of iterating over the controls of a device looking for the ones relevant to a given event, enumeration is done the opposite by efficiently searching through the memory contained in an event and then mapping data found in the event back to controls on a given device.

// Inefficient:
foreach (var control in device.allControls)
{
    // Skip control if it is noisy, synthetic, or not a leaf control.
    if (control.synthetic || control.noisy || control.children.Count > 0)
        continue;

    // Locate the control in the event.
    var statePtr = eventPtr.GetStatePtrFromStateEvent(eventPtr);
    if (statePtr == null)
        continue; // Control not included in event.

    // See if the control is actuated beyond a minimum threshold.
    if (control.EvaluateMagnitude(statePtr) < 0.001f)
        continue;

    Debug.Log($"Found actuated control {control}");
}

// Much more efficient:
foreach (var control in eventPtr.EnumerateControls(
    InputControlExtensions.Enumerate.IgnoreControlsInDefaultState,
    device: device,
    magnitudeThreshold: 0.001f))
{
    Debug.Log($"Found actuated control {control}");
}

Properties

Current

Declaration
public InputControl Current { get; }
Property Value
Type Description
InputControl

Methods

Dispose()

Declaration
public void Dispose()

MoveNext()

Declaration
public bool MoveNext()
Returns
Type Description
Boolean

Reset()

Declaration
public void Reset()

See Also