Question InputSystem.QueueDeltaStateEvent for bitfield

I have a custom device/layout. My button states are stored in a ushort bitfield.
InputSystem.QueueDeltaStateEvent throws an error.
Is there a workaround? Thanks much!

[InputControl(name = "buttonA", layout = "Button", bit = 0)]

[InputControl(name = "buttonB", layout = "Button", bit = 1)]

public ushort buttons;

InvalidOperationException: Cannot send delta state events against bitfield controls: Button:/AxisOrangeInputDevice/buttonB

 

Got same issue and this the only place on Internet where the subject is raised so I will try to answer the question for other people who encounter the same issue.

This error messages is triggered from this condition:

Code (CSharp):

1. if (control.stateBlock.bitOffset != 0)
2.     throw new InvalidOperationException($"Cannot send delta state events against bitfield controls: {control}");

So, you just cannot use

InputSystem.QueueDeltaStateEvent

on a

InputControl

that use bitfields (that was the case in your example with bit = 0 and bit = 1.


In my own case, it was due to

UnityEngine.InputSystem.TrackedDevice

.

Code (CSharp):

1. [InputControl(synthetic = true)]
2. public ButtonControl isTracked { get; private set; }

The message appeared when trying to set the delta state event on this

InputControl

. However there is no bit field manipulation so I do not understand why. When debugging, its

stateBlock.bitOffset

is 5.

My own code is based on

Unity.XR.Hands.XRHandDevice

and they use

InputSystem.InputSystem.QueueDeltaStateEvent(isTracked, false);

with no problem, but I cannot.

Well, a workaround is to get ride of

InputSystem.QueueDeltaStateEvent

and use

StateEvent.From

and

InputControl.WriteValueIntoEvent

.
Here is an example:

Code (CSharp):

1. using (StateEvent.From(this, out InputEventPtr eventPtr))
2. {
3. ...
4. devicePosition.WriteValueIntoEvent(position, eventPtr);
5. deviceRotation.WriteValueIntoEvent(rotation, eventPtr);
6. isTracked.WriteValueIntoEvent(isDeviceTracked ? 1.0f : 0.0f, eventPtr);
7. ...
8. }

Be really careful on the type you use when using

WriteValueIntoEvent

. For example, the

ButtonControl

use a float internally so you may want to set:

buttonControl.WriteValueIntoEvent(isPressed ? 1.0f : 0.0f);

instead of

buttonControl.WriteValueIntoEvent(isPressed);

 

I had the same issue and accidentally solved it.
Here's my code that gives

InvalidOperationException: Cannot send delta state events against bitfield controls

for

InputSystem.QueueDeltaStateEvent(poking, isPoking);

. However,

InputSystem.QueueDeltaStateEvent(grabbableGrabbed, isGrabbableGrabbed);

was working fine. This is weird because poking and grabbableGrabbed have the same types.

My solution is adding the

offset = 0

to the

[InputControl]

tag:

Code (CSharp):

1.     [InputControl(offset = 0)]
2.     public ButtonControl grabbableGrabbed { get; private set; }
3.    
4.     [InputControl(offset = 1)]
5.     public ButtonControl poking { get; private set; }

and updating works fine...

Code (CSharp):

1. InputSystem.QueueDeltaStateEvent(grabbableGrabbed, isGrabbableGrabbed);
2. InputSystem.QueueDeltaStateEvent(poking, isPoking);