COM Exception when building with IL2CPP

[hybridherbst]

When switching to the new Unity default compiler (IL2CPP) instead of Mono, SpaceNavigator stops working in a Windows build.

There's a COMException thrown:

System.Runtime.InteropServices.COMException (0x80020006): Error HRESULT E_FAIL has been returned from a call to a COM component.
  at TDx.TDxInput.DeviceClass.get_Sensor () [0x00000] in <00000000000000000000000000000000>:0 
  at SpaceNavigatorDriver.SpaceNavigatorWindows..ctor () [0x00000] in <00000000000000000000000000000000>:0 
  at SpaceNavigatorDriver.SpaceNavigatorWindows.get_SubInstance () [0x00000] in <00000000000000000000000000000000>:0 
  at SpaceNavigatorDriver.SpaceNavigator.get_Translation () [0x00000] in <00000000000000000000000000000000>:0 
  at FlyAround.Update () [0x00000] in <00000000000000000000000000000000>:0 
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:LogError(Object)
SpaceNavigatorDriver.SpaceNavigatorWindows:.ctor()
SpaceNavigatorDriver.SpaceNavigatorWindows:get_SubInstance()
SpaceNavigatorDriver.SpaceNavigator:get_Translation()

Switching back to Mono Scripting Backend makes it work again. Any ideas? What I noted is happening is that Il2CPP packs all .NET DLLs into a "GameAssembly.dll" and calls that. Maybe something checks that the calls are coming from the "right" DLL and prevents access otherwise? Not sure how to make it work in that case...

[PatHightree]

The TDx.TDxInput part comes from a dll by 3DConnexion that I use to interface with the device. Looks like this kind of interfacing is going the way of the dodo. I haven't got any quick fix for this. In the research/3dconnexion-connection branch I've got some research that investigates a new method for interfacing but it's windows-only afaik. It is functional, as in it reads data from the device without the requiring the dll. However, I haven't tested it with IL2CPP! So if anyone's up for it, you can try and integrate it into the master branch. I'm currently tied up in work, other projects and have a vacation coming up, so I won't be working on this project for the foreseeable future.

[hybridherbst]

I see, thank you. Not sure if integrating into the master branch is a good idea if it's not working on Mac yet - do you have numbers how many people are using this on Mac?

I'll try whether that works with IL2CPP though!

[PatHightree]

Yeah, I meant merge the master and research branches, preferably into another branch ;) I've got the package on the unity asset store, but they don't provide any platform-specific data. Only a total downloads number per month, which is always somewhere between 100 and 150. I hear mac-related feedback on a regular basis, so it's safe to assume a sizable portion of the downloads is mac.

[tufeixp]

I tested the research branch, still unable to run on windows 10 il2cpp standalone build!

NotSupportedException: IL2CPP does not support marshaling delegates that point to instance methods to native code. The method we're attempting to marshal is: SpaceNavigatorDriver.SpaceNavigatorWindows::wndProc at SpaceNavigatorDriver.SpaceNavigator.get_Instance () [0x00000] in <00000000000000000000000000000000>:0 at FlyAround.Update () [0x00000] in <00000000000000000000000000000000>:0

[PatHightree]

Closing this issue as with version 2.0.0, the driver has moved away from dll based communication to Unity's new Input System. I succesfully tested a IL2CPP build on Windows.