(SOLVED) odd bug with exotic IComparer function...

Hi guys, thought I would ask if any of you know of this issue:

Essentially, I am making a racing game, and my ranking system uses a generic list with all the players in it. On other platforms (read: this includes Windows Standalone!) this works correctly.

However, upon testing a WSA build (Universal 10), this build of my game has the ranking jumping all over the place! Basically, if I sit idle on the track, regardless if I am in first or at the very back, the ranking constantly jumps positions rather than actually stating the correct position. This only occurs on WSA, aka. if I make a build for android and run that, ranking shows up properly.

So I ask; is this a known windows-specific bug with generic lists, a bug in List<>.indexOf, or am I doing something completely screwed up?

Code for reference:

Code (csharp):

1.  
2. //In my update function, I do this:
3. racers.Sort(Compare);
4. //then I do this to get the racer position:
5. racers.IndexOf(playerData.GetComponent<RacerInfo>())+1;
6. //the +1 is so being in 1st doesn't appear as 0
7.  
8. //the actual sorting code is here. (this could be the issue, this code exists outside of update)
9. public int Compare(System.Object x, System.Object y) {
10.         RacerInfo c1 = (RacerInfo)x;
11.         RacerInfo c2 = (RacerInfo)y;
12.  
13.         if (c1.currLap > c2.currLap) return c2.currLap.CompareTo(c1.currLap);
14.         else if (c1.currPnt > c2.currPnt) return c2.currPnt.CompareTo(c1.currPnt);
15.         else return c1.dist2Next.CompareTo(c2.dist2Next);
16. }
17.  

I apologize for some formatting issues, this was due to a bug in Microsoft edge, meaning I had to copy/paste a line of code at a time...

I can also post a video clip of the bug for those wanting video footage

 

How would I go about doing that? I do see it fire up when I build with the green arrow, but where would I look? (I would assume in the Assembly.CSharp.dll)

EDIT: Huh, it won't run; it tells me "unable to debug .NET compilation code: catastrophic failure" any idea?

EDIT2: Oh wait, oops... I might have to turn on dev build first.

 

Oh wow, I will have to try that, thank you.

Ok, I dragged and dropped, do I just start the game? Sorry for asking too many questions, I haven't used VS much.

 

Ok, I tried this, and it didn't break at the point I specified. Do I need VS tools for this?

 

Ok, I think I have found the problem, it appears that IComparer is behaving differently in WSA. Any idea of this?

I need this fixed as, I will admit, the game affected by this bug is my Unity Dev Contest 2016 entry...

 

I will...
essentially, in every other platform I have tested (the editor included) the code (my IComparer) works properly.

However, THE EXACT SAME CODE behaves a completely different way on the Windows Store Platform! And I know it's the IComparer; I was actually able to reproduce the same odd behavior that only normally occurs on WSA by changing my code slightly. (the rank jumps around rather than actually sampling the positions properly) It's like using WSA as the build platform optimizes something out!

 

Here:

Code that works properly everywhere except WSA

Code (csharp):

1.  
2. public int Compare(System.Object x, System.Object y) {
3.         RacerInfo c1 = (RacerInfo)x;
4.         RacerInfo c2 = (RacerInfo)y;
5.  
6.         if (c1.currLap > c2.currLap) return c2.currLap.CompareTo(c1.currLap);
7.         else if (c1.currPnt > c2.currPnt) return c2.currPnt.CompareTo(c1.currPnt);
8.         else return c1.dist2Next.CompareTo(c2.dist2Next);
9. }
10.  

This code specifically reproduces the WSA bug everywhere else... I was able to do several other pieces that do it wrong as well.

Code (csharp):

1.  
2. public int Compare(System.Object x, System.Object y) {
3.         RacerInfo c1 = (RacerInfo)x;
4.         RacerInfo c2 = (RacerInfo)y;
5.  
6.         if (c1.currLap > c2.currLap) return 1;
7.         else if (c1.currPnt > c2.currPnt) return 1;
8.         else if (c1.dist2Next < c2.dist2Next) return 1;
9.         else return -1;
10. }
11.  

In fact, this doesn't only affect lists; it affects anything using IComparer I found (I switched to a static array to see if that would fix it, but to no avail... )

EDIT: Side-note; the player's car starts in 16th. In normal gameplay, it works as intended. in WSA however, it seems to almost always jump to "9" before going completely nuts!

 

One of them was (I changed it to an integer to avoid floating point precision errors)

Will try later. Have to go now. Thank you for the help.

 

Hi. I am back to say that you sir are an absolute genius!

I did have to tweak your IComparer function a little bit for it to work for ranking, as it was potentially returning the distance difference as well as the other two. By using the else statements instead, it made sure that if the other numbers are the same, return the distance for sorting. that way, at least one thing is returned.

Code (CSharp):

1.  
2. public int Compare(RacerInfo x, RacerInfo y)
3. {
4.         if (x.currLap != y.currLap)
5.                 return x.currLap < y.currLap ? 1 : -1;
6.         else if (x.currPnt != y.currPnt)
7.                 return x.currPnt < y.currPnt ? 1 : -1;
8.         else
9.                 return x.dist2Next < y.dist2Next ? -1 : 1;
10. }
11.  

(For those who want to use this code, substitute RacerInfo with either System.Object or your own car-tracking class!)

Now it works on all platforms, including WSA! And it works perfectly. Thank you for your help!