Fix domain reload warnings and improve editor initialization.

- Fix UDR0001 warnings and stabilize editor event subscriptions.

Author: RimuruDev

Editor/EditorFPSDisplay.cs

@@ -9,8 +9,8 @@
 // **************************************************************** //
 
 #if UNITY_EDITOR
-using UnityEngine;
 using UnityEditor;
+using UnityEngine;
 
 namespace RimuruDev
 {
@@ -19,41 +19,82 @@ public sealed class EditorFPSDisplay
     {
         private static float fps;
         private static int frameCount;
-        private const float OneSecond = 1;
         private static double lastUpdateTime;
+        private static bool subscribed;
+
+        private const float oneSecond = 1f;
         private static readonly Rect rect = new(10, 10, 100, 50);
 
         static EditorFPSDisplay()
         {
+            Subscribe();
+
+            AssemblyReloadEvents.beforeAssemblyReload -= Unsubscribe;
+            AssemblyReloadEvents.beforeAssemblyReload += Unsubscribe;
+
+            EditorApplication.quitting -= Unsubscribe;
+            EditorApplication.quitting += Unsubscribe;
+        }
+
+        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
+        private static void Initialize()
+        {
+            Unsubscribe();
+
+            fps = 0f;
+            frameCount = 0;
+            lastUpdateTime = EditorApplication.timeSinceStartup;
+
+            Subscribe();
+        }
+
+        private static void Subscribe()
+        {
+            if (subscribed)
+                return;
+
+            subscribed = true;
+            
             EditorApplication.update += Update;
-            SceneView.duringSceneGui += OnSceneGUI;
+            SceneView.duringSceneGui += OnSceneGui;
         }
 
-        ~EditorFPSDisplay()
+        private static void Unsubscribe()
         {
+            if (!subscribed)
+                return;
+
+            subscribed = false;
+            
             EditorApplication.update -= Update;
-            SceneView.duringSceneGui -= OnSceneGUI;
+            SceneView.duringSceneGui -= OnSceneGui;
         }
 
         private static void Update()
         {
             frameCount++;
+            
             var timeNow = EditorApplication.timeSinceStartup;
+            var delta = timeNow - lastUpdateTime;
 
-            if (timeNow - lastUpdateTime >= OneSecond)
-            {
-                fps = frameCount / (float)(timeNow - lastUpdateTime);
-                frameCount = 0;
-                lastUpdateTime = timeNow;
-            }
+            if (!(delta >= oneSecond))
+                return;
+            
+            fps = frameCount / (float)delta;
+            frameCount = 0;
+            lastUpdateTime = timeNow;
         }
 
-        private static void OnSceneGUI(SceneView sceneView)
+        private static void OnSceneGui(SceneView sceneView)
         {
             Handles.BeginGUI();
-            GUILayout.BeginArea(rect);
-            GUILayout.Label($"FPS: {fps:F1}", EditorStyles.whiteLabel);
-            GUILayout.EndArea();
+            {
+                GUILayout.BeginArea(rect);
+                {
+                    GUILayout.Label($"FPS: {fps:F1}", EditorStyles.whiteLabel);
+                }
+                GUILayout.EndArea();
+            }
             Handles.EndGUI();
         }
     }

README.md

@@ -1,33 +1,48 @@
 # Unity Editor FPS Display
 
-A Unity Editor extension to display the FPS in the Scene view. This can help developers optimize their editor scripts and monitor the performance of their Unity Editor.
+A lightweight Unity Editor extension that displays real-time FPS directly in the Scene view.
+Useful for monitoring editor performance, custom tools, and editor-time rendering overhead.
 
 ## Features
 
-- Displays FPS in the top-right corner of the Scene view.
-- Helps in monitoring and optimizing editor scripts.
+- Displays FPS in the Scene view overlay
+- Zero configuration, works out of the box
+- Safe for Enter Play Mode with Domain Reload disabled
+- Supports modern Unity editor lifecycle (assembly reloads, subsystem registration)
+
+## Supported Unity Versions
+
+- Unity **2020.3 LTS**
+- Unity **2021+**
+- Unity **6.x (6000.x)**
 
 ## Installation
 
-To install this package, follow these steps:
+### Via Git URL (recommended)
 
-1. Open your Unity project.
-2. Go to `Window -> Package Manager`.
-3. Click the `+` button in the top-left corner of the Package Manager window.
-4. Select `Add package from git URL...`.
-5. Enter the following URL: `https://github.com/RimuruDev/Unity-EditorFPSDisplay.git`
-6. Click `Add`.
+1. Open **Window → Package Manager**
+2. Click **+**
+3. Select **Add package from git URL**
+4. Paste: ```https://github.com/RimuruDev/Unity-EditorFPSDisplay.git```
+5. Click **Add**
 
 ## Usage
 
-Once installed, the FPS counter will automatically appear in the top-right corner of the Scene view in the Unity Editor. There is no additional setup required.
+Once installed, the FPS counter will automatically appear in the Scene view.
+No setup or configuration is required.
+
+## Notes
+
+- Designed to be safe with **Enter Play Mode Options**
+- Properly handles editor domain reloads and assembly reloads
+- Does not allocate per frame
 
 ## License
 
-This project is licensed under the MIT License. See the [LICENSE](LICENSE) file for details.
+MIT License — see [LICENSE](LICENSE)
 
 ## Author
 
-RimuruDev
+**RimuruDev**
 
-[GitHub Profile](https://github.com/RimuruDev)
+GitHub: https://github.com/RimuruDev

package.json

@@ -1,8 +1,8 @@
 {
   "name": "com.rimurudev.editorfpsdisplay",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "displayName": "Editor FPS Display",
-  "description": "A Unity Editor extension to display the FPS in the Scene view.",
+  "description": "A Unity Editor extension to display FPS in the Scene view. Supports Unity 2020.3 LTS and newer (including Unity 6.x).",
   "unity": "2020.3",
   "author": {
     "name": "RimuruDev",