FIX: canRunInBackground not set correctly for VR devices (#1233).

Author: mattdatwork

Assets/Tests/InputSystem/CoreTests_Devices.cs

@@ -1768,6 +1768,61 @@ public void Devices_QueryTheirEnabledStateFromRuntime()
         Assert.That(receivedQueryEnabledStateCommand, Is.Null);
     }
 
+    [Test]
+    [Category("Devices")]
+    public unsafe void Devices_CanMarkDeviceAsBeingAbleToRunInBackground()
+    {
+        var device1Id = runtime.ReportNewInputDevice<Gamepad>();
+        var device2Id = runtime.ReportNewInputDevice<Mouse>();
+
+        var receivedCanRunInBackgroundForDevice1 = false;
+        var receivedCanRunInBackgroundForDevice2 = false;
+
+        runtime.SetDeviceCommandCallback(device1Id,
+            (id, command) =>
+            {
+                if (command->type != QueryCanRunInBackground.Type)
+                    return InputDeviceCommand.GenericFailure;
+
+                Assert.That(id, Is.EqualTo(device1Id));
+                Assert.That(command->payloadSizeInBytes, Is.EqualTo(UnsafeUtility.SizeOf<bool>()));
+
+                receivedCanRunInBackgroundForDevice1 = true;
+                ((QueryCanRunInBackground*)command)->canRunInBackground = true;
+                return InputDeviceCommand.GenericSuccess;
+            });
+        runtime.SetDeviceCommandCallback(device2Id,
+            (id, command) =>
+            {
+                if (command->type != QueryCanRunInBackground.Type)
+                    return InputDeviceCommand.GenericFailure;
+
+                Assert.That(id, Is.EqualTo(device2Id));
+                Assert.That(command->payloadSizeInBytes, Is.EqualTo(UnsafeUtility.SizeOf<bool>()));
+
+                receivedCanRunInBackgroundForDevice2 = true;
+                ((QueryCanRunInBackground*)command)->canRunInBackground = false;
+                return InputDeviceCommand.GenericSuccess;
+            });
+
+        InputSystem.Update();
+
+        // Just adding the device should not have triggered a query for canRunInBackground.
+        Assert.That(receivedCanRunInBackgroundForDevice1, Is.False);
+        Assert.That(receivedCanRunInBackgroundForDevice2, Is.False);
+
+        var device1 = InputSystem.GetDeviceById(device1Id);
+        var device2 = InputSystem.GetDeviceById(device2Id);
+
+        var device1CanRunInBackground = device1.canRunInBackground;
+        var device2CanRunInBackground = device2.canRunInBackground;
+
+        Assert.That(receivedCanRunInBackgroundForDevice1, Is.True);
+        Assert.That(receivedCanRunInBackgroundForDevice2, Is.True);
+        Assert.That(device1CanRunInBackground, Is.True);
+        Assert.That(device2CanRunInBackground, Is.False);
+    }
+
     [Test]
     [Category("Devices")]
     public void Devices_NativeDevicesAreFlaggedAsSuch()

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -19,6 +19,7 @@ however, it has to be formatted properly to pass verification tests.
 ### Fixed
 
 - Fixed precompiled layouts such as `FastKeyboard` leading to build time regressions with il2cpp (case 1283676).
+- Fixed `InputDevice.canRunInBackground` not being correctly set for VR devices (thus not allowing them to receive input while the application is not focused).
 - Fixed `InputUser.OnEvent` and `RebindingOperation.OnEvent` exhibiting bad performance profiles and leading to multi-millisecond input update times (case 1253371).
   * In our own measurements, `InputUser.OnEvent` is >9 times faster than before and `RebindingOperation.OnEvent` is ~2.5 times faster.
 - Fixed PS4 controller not recognized on Mac when connected over Bluetooth ([case 1286449](https://issuetracker.unity3d.com/issues/input-system-dualshock-4-zct1e-dualshock-2-v1-devices-are-not-fully-recognised-over-bluetooth)).

Packages/com.unity.inputsystem/InputSystem/Devices/Commands/InputDeviceCommand.cs

@@ -52,10 +52,7 @@ public struct InputDeviceCommand : IInputDeviceCommandInfo
         [FieldOffset(0)] public FourCC type;
         [FieldOffset(4)] public int sizeInBytes;
 
-        public int payloadSizeInBytes
-        {
-            get { return sizeInBytes - kBaseCommandSize; }
-        }
+        public int payloadSizeInBytes => sizeInBytes - kBaseCommandSize;
 
         public unsafe void* payloadPtr
         {

Packages/com.unity.inputsystem/InputSystem/Devices/Commands/QueryCanRunInBackground.cs

@@ -12,7 +12,7 @@ public struct QueryCanRunInBackground : IInputDeviceCommandInfo
     {
         public static FourCC Type => new FourCC('Q', 'R', 'I', 'B');
 
-        internal const int kSize = InputDeviceCommand.kBaseCommandSize;
+        internal const int kSize = InputDeviceCommand.kBaseCommandSize + sizeof(bool);
 
         [FieldOffset(0)]
         public InputDeviceCommand baseCommand;