Class InputDevice

Represents an input device which is always the root of a hierarchy of InputControl instances.

Inheritance
System.Object
InputControl
InputDevice
Gamepad
HID
Joystick
Keyboard
Pointer
Sensor
OculusRemote
OculusTrackingReference
ViveLighthouse
ViveTracker
XRController
XRHMD
Inherited Members
Namespace: UnityEngine.InputSystem
Syntax
public class InputDevice : InputControl
Remarks

Input devices act as the container for control hierarchies. Every hierarchy has to have a device at the root. Devices cannot occur as children of other controls.

Devices are usually created automatically in response to hardware being discovered by the Unity runtime. However, it is possible to manually add devices using methods such as AddDevice<TDevice>(String).

Add a "synthetic" gamepad that isn't actually backed by hardware: 
var gamepad = InputSystem.AddDevice<Gamepad>();

There are subclasses representing the most common types of devices, like Mouse, Keyboard, Gamepad, and Touchscreen.

To create your own types of devices, you can derive from InputDevice and register your device as a new "layout".

Creating a custom type of input device. 
// InputControlLayoutAttribute attribute is only necessary if you want
// to override default behavior that occurs when registering your device
// as a layout.
// The most common use of InputControlLayoutAttribute is to direct the system
// to a custom "state struct" through the `stateType` property. See below for details.
[InputControlLayout(displayName = "My Device", stateType = typeof(MyDeviceState))]
#if UNITY_EDITOR
[InitializeOnLoad]
#endif
public class MyDevice : InputDevice
{
    public ButtonControl button { get; private set; }
    public AxisControl axis { get; private set; }

    // Register the device.
    static MyDevice()
    {
        // In case you want instance of your device to automatically be created
        // when specific hardware is detected by the Unity runtime, you have to
        // add one or more "device matchers" (InputDeviceMatcher) for the layout.
        // These matchers are compared to an InputDeviceDescription received from
        // the Unity runtime when a device is connected. You can add them either
        // using InputSystem.RegisterLayoutMatcher() or by directly specifying a
        // matcher when registering the layout.
        InputSystem.RegisterLayout<MyDevice>(
            // For the sake of demonstration, let's assume your device is a HID
            // and you want to match by PID and VID.
            matches: new InputDeviceMatcher()
                .WithInterface("HID")
                .WithCapability("PID", 1234)
                .WithCapability("VID", 5678));
    }

    // This is only to trigger the static class constructor to automatically run
    // in the player.
    [RuntimeInitializeOnLoadMethod]
    private static void InitializeInPlayer() {}

    protected override void FinishSetup()
    {
        base.FinishSetup();
        button = GetChildControl<ButtonControl>("button");
        axis = GetChildControl<AxisControl>("axis");
    }
}

// A "state struct" describes the memory format used a device. Each device can
// receive and store memory in its custom format. InputControls are then connected
// the individual pieces of memory and read out values from them.
[StructLayout(LayoutKind.Explicit, Size = 32)]
public struct MyDeviceState : IInputStateTypeInfo
{
    // In the case of a HID (which we assume for the sake of this demonstration),
    // the format will be "HID". In practice, the format will depend on how your
    // particular device is connected and fed into the input system.
    // The format is a simple FourCC code that "tags" state memory blocks for the
    // device to give a base level of safety checks on memory operations.
    public FourCC format => return new FourCC('H', 'I', 'D');

    // InputControlAttributes on fields tell the input system to create controls
    // for the public fields found in the struct.

    // Assume a 16bit field of buttons. Create one button that is tied to
    // bit #3 (zero-based). Note that buttons do not need to be stored as bits.
    // They can also be stored as floats or shorts, for example.
    [InputControl(name = "button", layout = "Button", bit = 3)]
    public ushort buttons;

    // Create a floating-point axis. The name, if not supplied, is taken from
    // the field.
    [InputControl(layout = "Axis")]
    public short axis;
}

Devices can have usages like any other control (usages). Unlike other controls, however, usages of InputDevices are allowed to be changed on the fly without requiring a change to the device layout (see SetDeviceUsage(InputDevice, String)).

Constructors

InputDevice()

This constructor is public for the sake of Activator.CreateInstance only. To construct devices, use methods such as AddDevice<TDevice>(String). Manually using new on InputDevice will not result in a usable device.

Declaration
public InputDevice()

Fields

InvalidDeviceId

Value of an invalid id.

Declaration
public const int InvalidDeviceId = 0
Field Value
Type Description
System.Int32
Remarks

The input system will not assigned this ID to any device.

Properties

added

Whether the device has been added to the system.

Declaration
public bool added { get; }
Property Value
Type Description
System.Boolean
Remarks

Input devices can be constructed manually through UnityEngine.InputSystem.Layouts.InputDeviceBuilder. Also, they can be removed through RemoveDevice(InputDevice). This property reflects whether the device is currently added to the system.

Note that devices in disconnectedDevices will all have this property return false.

See Also

all

Return all input devices currently added to the system.

Declaration
public static ReadOnlyArray<InputDevice> all { get; }
Property Value
Type Description
ReadOnlyArray<InputDevice>
Remarks

This is equivalent to devices.

allControls

A flattened list of controls that make up the device.

Declaration
public ReadOnlyArray<InputControl> allControls { get; }
Property Value
Type Description
ReadOnlyArray<InputControl>
Remarks

Does not allocate.

canRunInBackground

If true, the device is capable of delivering input while the application is running in the background.

Declaration
public bool canRunInBackground { get; }
Property Value
Type Description
System.Boolean
Remarks

Note that by default, even if capable of doing so, devices will not generate input while the application is not focused. To enable the behavior, use .

description

Metadata describing the device (product name etc.).

Declaration
public InputDeviceDescription description { get; }
Property Value
Type Description
InputDeviceDescription
Remarks

The description of a device is unchanging over its lifetime and does not comprise data about a device's configuration (which is considered mutable).

enabled

Whether the device is currently enabled (i.e. sends and receives events).

Declaration
public bool enabled { get; }
Property Value
Type Description
System.Boolean
Remarks

A device that is disabled will not receive events. I.e. events that are being sent to the device will be ignored.

When disabling a native device, a DisableDeviceCommand will also be sent to the IInputRuntime. It depends on the specific runtime whether the device command is supported but if it is, the device will be disabled in the runtime and no longer send events. This is especially important for devices such as Sensor that incur both computation and battery consumption overhead while enabled.

Specific types of devices can choose to start out in disabled state by default. This is generally the case for Sensor to ensure that their overhead is only incurred when actually being used by the application.

See Also

id

Unique numeric ID for the device.

Declaration
public int id { get; }
Property Value
Type Description
System.Int32
Remarks

This is only assigned once a device has been added to the system. No two devices will receive the same ID and no device will receive an ID that another device used before even if the device was removed. The only exception to this is if a device gets re-created as part of a layout change. For example, if a new layout is registered that replaces the Mouse layout, all Mouse devices will get recreated but will keep their existing device IDs.

IDs are assigned by the input runtime.

See Also

lastUpdateTime

Timestamp of last state event used to update the device.

Declaration
public double lastUpdateTime { get; }
Property Value
Type Description
System.Double
Remarks

Events other than StateEvent and DeltaStateEvent will not cause lastUpdateTime to be changed.

native

Whether the device comes from the IInputRuntime

Declaration
public bool native { get; }
Property Value
Type Description
System.Boolean
Remarks

Devices can be discovered when onDeviceDiscovered by the runtime or they can be added manually through the various AddDevice(InputDevice) APIs. Devices reported by the runtime will return true for this property whereas devices added manually will return false.

Devices reported by the runtime will usually come from the Unity engine itself.

See Also

remote

Whether the device is mirrored from a remote input system and not actually present as a "real" device in the local system.

Declaration
public bool remote { get; }
Property Value
Type Description
System.Boolean
See Also

updateBeforeRender

Whether the device requires an extra update before rendering.

Declaration
public bool updateBeforeRender { get; }
Property Value
Type Description
System.Boolean
Remarks

The value of this property is determined by updateBeforeRender in the device's InputControlLayout.

The extra update is necessary for tracking devices that are used in rendering code. For example, the eye transforms of an HMD should be refreshed right before rendering as refreshing only in the beginning of the frame will lead to a noticeable lag.

See Also

valueSizeInBytes

Declaration
public override int valueSizeInBytes { get; }
Property Value
Type Description
System.Int32
Overrides

valueType

Declaration
public override Type valueType { get; }
Property Value
Type Description
System.Type
Overrides

wasUpdatedThisFrame

Declaration
public bool wasUpdatedThisFrame { get; }
Property Value
Type Description
System.Boolean

Methods

CompareValue(Void*, Void*)

Declaration
public override bool CompareValue(void *firstStatePtr, void *secondStatePtr)
Parameters
Type Name Description
System.Void* firstStatePtr
System.Void* secondStatePtr
Returns
Type Description
System.Boolean
Overrides

ExecuteCommand<TCommand>(ref TCommand)

Declaration
public long ExecuteCommand<TCommand>(ref TCommand command)
    where TCommand : struct, IInputDeviceCommandInfo
Parameters
Type Name Description
TCommand command
Returns
Type Description
System.Int64
Type Parameters
Name Description
TCommand

MakeCurrent()

Make this the current device of its type.

Declaration
public virtual void MakeCurrent()
Remarks

Use this to set static properties that give fast access to the latest device used of a given type (current or leftHand and rightHand).

This functionality is somewhat like a 'pwd' for the semantic paths but one where there can be multiple current working directories, one for each type.

A device will be made current by the system initially when it is created and subsequently whenever it receives an event.

OnAdded()

Declaration
protected virtual void OnAdded()

OnRemoved()

Declaration
protected virtual void OnRemoved()

ReadValueFromBufferAsObject(Void*, Int32)

Declaration
public override object ReadValueFromBufferAsObject(void *buffer, int bufferSize)
Parameters
Type Name Description
System.Void* buffer
System.Int32 bufferSize
Returns
Type Description
System.Object
Overrides

ReadValueFromStateAsObject(Void*)

Declaration
public override object ReadValueFromStateAsObject(void *statePtr)
Parameters
Type Name Description
System.Void* statePtr
Returns
Type Description
System.Object
Overrides

ReadValueFromStateIntoBuffer(Void*, Void*, Int32)

Declaration
public override void ReadValueFromStateIntoBuffer(void *statePtr, void *bufferPtr, int bufferSize)
Parameters
Type Name Description
System.Void* statePtr
System.Void* bufferPtr
System.Int32 bufferSize
Overrides

Extension Methods

See Also