Changed implementation of IDisposable to proper way.

RecrownedAthenaeum/ScreenSystem/ScreenManager.cs

@@ -1,10 +1,12 @@
-using Microsoft.Xna.Framework;
+using Microsoft.Win32.SafeHandles;
+using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
 using RecrownedAthenaeum.Camera;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading.Tasks;
 
@@ -14,6 +16,8 @@ namespace RecrownedAthenaeum.ScreenSystem
 
     public class ScreenManager : IDisposable
     {
+        bool disposed = false;
+
         public event FirstScreenChange RequireNextScreenEvent;
         private GraphicsDeviceManager graphics;
         private Screen previousScreen;
@@ -131,7 +135,18 @@ namespace RecrownedAthenaeum.ScreenSystem
 
         public void Dispose()
         {
-            previousScreenRenderTarget?.Dispose();
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        public virtual void Dispose(bool disposing)
+        {
+            if (disposed) return;
+            if (disposing)
+            {
+                previousScreenRenderTarget?.Dispose();
+            }
+            disposing = true;
         }
     }
 }