Assign a player number to each UniQuake instance in split-screen as opposed to providing a library override. The UniQuake class can decide for itself how this maps to an alternate library filename. This player number is also provided to FMOD which allows its localized audio for split-screen feature to work properly.

Assets/Scenes/SplitScreenTest.unity

@@ -158,22 +158,22 @@ MonoBehaviour:
     baseGame: 0
     modPath: 
     arguments: 
-    libraryName: 
+    playerNumber: 1
   - mainCamera: {fileID: 821010101}
     baseGame: 1
     modPath: 
     arguments: 
-    libraryName: uniquake2
+    playerNumber: 2
   - mainCamera: {fileID: 1512894441}
     baseGame: 2
     modPath: 
     arguments: 
-    libraryName: uniquake3
+    playerNumber: 3
   - mainCamera: {fileID: 506815091}
     baseGame: 0
     modPath: dopa
     arguments: 
-    libraryName: uniquake4
+    playerNumber: 4
   visualStyles:
   - {fileID: 11400000, guid: d187fe54fb9a3e047bf4cec083877e72, type: 2}
 --- !u!4 &157597865

Assets/Scripts/SplitScreenTest.cs

@@ -31,7 +31,7 @@ public class SplitScreenTest : MonoBehaviour
             uq.Camera = gameInstance.mainCamera;
             uq.GameLayer = gameLayer;
             uq.ViewModelLayer = viewLayer;
-            uq.LibraryOverride = gameInstance.libraryName;
+            uq.PlayerNumber = gameInstance.playerNumber;
             uq.SetVisualStyle(visualStyles[0]);
 
             gameLayer += layerStride;
@@ -58,6 +58,6 @@ public class SplitScreenTest : MonoBehaviour
 
         public string arguments;
 
-        public string libraryName;
+        public int playerNumber;
     }
 }

Assets/Scripts/UniQuake.Interop.cs

@@ -44,11 +44,12 @@ public partial class UniQuake
         string dllFile = Path.Combine(Application.dataPath, DllPath);
 
         // Experimental code to allow running multiple instances of Quake next to each other
-        if (!string.IsNullOrEmpty(LibraryOverride))
+        if (PlayerNumber > 1)
         {
             string directory = Path.GetDirectoryName(dllFile);
+            string filename = Path.GetFileNameWithoutExtension(dllFile);
             string extension = Path.GetExtension(dllFile);
-            dllFile = Path.Combine(directory, LibraryOverride + extension);
+            dllFile = Path.Combine(directory, filename + PlayerNumber + extension);
         }
         
         libraryHandle = SystemLibrary.LoadLibrary(dllFile);

Assets/Scripts/UniQuake.cs

@@ -28,7 +28,7 @@ public partial class UniQuake: MonoBehaviour
     public string ModDirectory { get; set; }
     public string[] AdditionalArguments { get; set; }
     
-    public string LibraryOverride { get; set; }
+    public int PlayerNumber { get; set; }
     
     /// <summary>
     /// Time since startup for this particular instance of Quake
@@ -101,7 +101,7 @@ public partial class UniQuake: MonoBehaviour
 
         try
         {
-            UniQuake_SetFmodSystem(AudioManager.Instance.FmodSystem.handle);
+            UniQuake_SetFmodSystem(AudioManager.Instance.FmodSystem.handle, PlayerNumber);
             UniQuake_SetSysCallbacks(systemModule.ContextPtr, systemModule.CallbacksPtr);
             UniQuake_SetRenderCallbacks(renderModule.ContextPtr, renderModule.CallbacksPtr);
             UniQuake_SetGameCallbacks(gameModule.ContextPtr, gameModule.CallbacksPtr);