Mathf.Approximately failing on SteamOS

Hi,

My Linux build runs fine under Ubuntu, but is failing in odd ways when running on Steam Deck. After some digging, I've narrowed down one issue to Mathf.Approximately seemingly always returning false when running on Steam Deck.

As an example, this code produces debug output when run on Steam Deck:

Code (CSharp):

1. float testFloat = 0f;
2. if (!Mathf.Approximately(testFloat, 0f))
3. {
4.     Debug.LogFormat(LogType.Error, LogOption.NoStacktrace, null, "0 is not approximately 0!");
5. }

Running the exact same build on Ubuntu, I get no output (and, similarly, I don't see this problem on Windows or console platform).

I'm at a bit of a loss what to do about this. Has anybody seen anything similar or have any suggestions?

Probably worth noting that the game also hangs on exit on Steam Deck (again, fine on other platforms, and the same build exits cleanly on Ubuntu).

I see the same problem with both Mono and il2cpp Linux builds. This is with Unity 2020.3, but I've tried the newer LTS version with the same results.

 

Did you try replacing Approximately by

Code (CSharp):

1. if (Mathf.Abs(testFloat - 0f) > Mathf.Epsilon)

or

Code (CSharp):

1. if (Mathf.Abs(testFloat -0f) > 0.000001f)

?

The implementation of Approximately is a bit weird. I'm sure there is a good reason for it but I don't know what that is. Maybe SteamOS libs are compiled with different floating point options and this is what's causing the issue, just a guess.

 

Thanks, yeah, I did that to fix one specific case but unfortunately Mathf.Approximately is used pretty heavily in an asset I'm relying on.

I might have to write a replacement function and do a big search and replace. Though I'm concerned that if this is broken, other things might be too. The hang on exit is also a bit worrying.

Going to try to make a minimal repro case to see if it happens in a blank project.