More code organization; putting QuakeParms in its own file and encapsulating the nitty gritty unmanaged code details, to make things overall more readable.

Assets/Scripts/QuakeParms.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Runtime.InteropServices;
+
+[StructLayout(LayoutKind.Sequential, Pack = 0)]
+public class QuakeParms
+{
+    private const int MaxArgs = 50;     // Corresponds with MAX_NUM_ARGVS in engine
+        
+    [MarshalAs(UnmanagedType.LPStr)]
+    public string baseDir;
+        
+    [MarshalAs(UnmanagedType.LPStr)]
+    public string cacheDir;
+        
+    public int argc;
+        
+    [MarshalAs(UnmanagedType.LPArray, SizeConst = MaxArgs)] 
+    public IntPtr[] argv;
+        
+    public IntPtr memBase;
+        
+    public int memSize;
+
+    public void SetArguments(string[] arguments)
+    {
+        argc = arguments.Length;
+        argv = new IntPtr[MaxArgs];
+        for (int i = 0; i < arguments.Length && i < MaxArgs; ++i)
+        {
+            argv[i] = Marshal.StringToHGlobalAnsi(arguments[i]);
+        }
+    }
+
+    public void AllocateMemory(int memorySize)
+    {
+        memSize = memorySize;
+        memBase = Marshal.AllocHGlobal(memorySize);
+    }
+        
+    public void Destroy()
+    {
+        if (memBase != IntPtr.Zero)
+        {
+            Marshal.FreeHGlobal(memBase);
+            memBase = IntPtr.Zero;
+        }
+
+        if (argv != null)
+        {
+            for (int i = 0; i < argv.Length; ++i)
+            {
+                if (argv[i] != IntPtr.Zero)
+                {
+                    Marshal.FreeHGlobal(argv[i]);
+                    argv[i] = IntPtr.Zero;
+                }
+            }
+        }
+    }
+}

Assets/Scripts/QuakeParms.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 88fe123889034941854842da9720545b
+timeCreated: 1617028874

Assets/Scripts/UniQuake.cs

@@ -1,6 +1,4 @@
 using System;
-using System.Collections;
-using System.Collections.Generic;
 using System.Runtime.InteropServices;
 using UnityEngine;
 
@@ -8,7 +6,6 @@ public class UniQuake: MonoBehaviour
 {
     private const string DllName = "uniquake.dll";
     private const int MemSize = 0x4000000;  // 64 MB of heap space
-    private const int MaxArgs = 50;     // Corresponds with MAX_NUM_ARGVS in engine
 
     private QuakeParms quakeParms;
     private SysCalls sysCalls;
@@ -23,21 +20,13 @@ public class UniQuake: MonoBehaviour
             "-height", "1080",
         };
 
-        IntPtr[] argv = new IntPtr[MaxArgs];
-        for (int i = 0; i < arguments.Length && i < MaxArgs; ++i)
-        {
-            argv[i] = Marshal.StringToHGlobalAnsi(arguments[i]);
-        }
-        
         quakeParms = new QuakeParms
         {
             baseDir = Application.persistentDataPath,
             cacheDir = null,
-            argc = arguments.Length,
-            argv = argv,
-            memBase = Marshal.AllocHGlobal(MemSize),
-            memSize = MemSize,
         };
+        quakeParms.SetArguments(arguments);
+        quakeParms.AllocateMemory(MemSize);
 
         sysCalls = new SysCalls(this);
 
@@ -55,23 +44,8 @@ public class UniQuake: MonoBehaviour
 
         if (quakeParms != null)
         {
-            if (quakeParms.memBase != IntPtr.Zero)
-            {
-                Marshal.FreeHGlobal(quakeParms.memBase);
-                quakeParms.memBase = IntPtr.Zero;
-            }
-
-            if (quakeParms.argv != null)
-            {
-                for (int i = 0; i < quakeParms.argv.Length; ++i)
-                {
-                    if (quakeParms.argv[i] != IntPtr.Zero)
-                    {
-                        Marshal.FreeHGlobal(quakeParms.argv[i]);
-                        quakeParms.argv[i] = IntPtr.Zero;
-                    }
-                }
-            }
+            quakeParms.Destroy();
+            quakeParms = null;
         }
     }
 
@@ -80,23 +54,4 @@ public class UniQuake: MonoBehaviour
 
     [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
     private static extern void UniQuake_Update(float deltaTime);
-
-    [StructLayout(LayoutKind.Sequential, Pack = 0)]
-    private class QuakeParms
-    {
-        [MarshalAs(UnmanagedType.LPStr)]
-        public string baseDir;
-        
-        [MarshalAs(UnmanagedType.LPStr)]
-        public string cacheDir;
-        
-        public int argc;
-        
-        [MarshalAs(UnmanagedType.LPArray, SizeConst = MaxArgs)] 
-        public IntPtr[] argv;
-        
-        public IntPtr memBase;
-        
-        public int memSize;
-    }
 }