<!--
{
  "availability" : [
    "iOS: 16.0.0 -",
    "iPadOS: 16.0.0 -",
    "macCatalyst: 16.0.0 -",
    "macOS: 13.0.0 -",
    "tvOS: 16.0.0 -",
    "visionOS: 1.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "GameController",
  "identifier" : "/documentation/GameController/GCDevicePhysicalInputStateDiff",
  "metadataVersion" : "0.1.0",
  "role" : "Protocol",
  "symbol" : {
    "kind" : "Protocol",
    "modules" : [
      "Game Controller"
    ],
    "preciseIdentifier" : "c:objc(pl)GCDevicePhysicalInputStateDiff"
  },
  "title" : "GCDevicePhysicalInputStateDiff"
}
-->

# GCDevicePhysicalInputStateDiff

The common functions for objects that contain the differences between a current and previous input state object.

```
protocol GCDevicePhysicalInputStateDiff : NSObjectProtocol
```

## Overview

Use the `GCDevicePhysicalInput` [`nextInputState()`](/documentation/GameController/GCDevicePhysicalInput/nextInputState()) method to get an input state object conforming to this protocol.

## Topics

### Getting changes

[`change(for:)`](/documentation/GameController/GCDevicePhysicalInputStateDiff/change(for:))

Returns whether the input value of an element changes.

[`GCDevicePhysicalInputElementChange`](/documentation/GameController/GCDevicePhysicalInputElementChange)

Possible values that describe whether the input value of an element changes.

[`changedElements()`](/documentation/GameController/GCDevicePhysicalInputStateDiff/changedElements()-9cdq4)

Returns the elements that changed since the previous input state.

[`changedElements()`](/documentation/GameController/GCDevicePhysicalInputStateDiff/changedElements()-2zzwm)

Returns the elements that changed since the previous input state.

[`changedElements`](/documentation/GameController/GCDevicePhysicalInputStateDiff/changedElements)

Returns the elements that changed since the previous input state.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)