Add TomlTypeConverter for UnityEngine.Rect

Originally pull request #510

Co-authored-by: ManlyMarco <39247311+manlymarco@users.noreply.github.com>

Runtimes/Unity/BepInEx.Unity.Mono/UnityTomlTypeConverters.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Globalization;
 using System.Runtime.CompilerServices;
 using BepInEx.Configuration;
 using UnityEngine;
@@ -36,5 +37,47 @@ internal static class UnityTomlTypeConverters
         TomlTypeConverter.AddConverter(typeof(Vector3), jsonConverter);
         TomlTypeConverter.AddConverter(typeof(Vector4), jsonConverter);
         TomlTypeConverter.AddConverter(typeof(Quaternion), jsonConverter);
+        TomlTypeConverter.AddConverter(typeof(Rect), new TypeConverter
+        {
+            ConvertToObject = StringToRect,
+            ConvertToString = RectToString
+        });
+    }
+
+    private static object StringToRect(string s, Type type)
+    {
+        // JsonUtility doesn't work with Rect on all Unity versions, so parse it manually
+        Rect result = default(Rect);
+
+        if (s == null)
+            return result;
+
+        string cleaned = s.Trim('{', '}').Replace(" ", "");
+        foreach (string part in cleaned.Split(','))
+        {
+            string[] parts = part.Split(':');
+            if (parts.Length != 2 || !float.TryParse(parts[1], out float value))
+                continue;
+
+            string id = parts[0].Trim('"');
+            if (id == "x")
+                result.x = value;
+            else if (id == "y")
+                result.y = value;
+            else if (id == "width" || id == "z")
+                result.width = value;
+            else if (id == "height" || id == "w")
+                result.height = value;
+        }
+
+        return result;
+    }
+
+    private static string RectToString(object o, Type type)
+    {
+        Rect rect = (Rect)o;
+        return string.Format(CultureInfo.InvariantCulture,
+                             "{{ \"x\":{0}, \"y\":{1}, \"width\":{2}, \"height\":{3} }}",
+                             rect.x, rect.y, rect.width, rect.height);
     }
 }