add event for GameLoader.LoadThread (#985)

Author: microlith57

Celeste.Mod.mm/Mod/Everest/Everest.Events.cs

@@ -94,6 +94,17 @@ internal static void CreateButtons(_OuiMainMenu menu, List<MenuButton> buttons)
                     => OnCreateButtons?.Invoke(menu, buttons);
             }
 
+            public static class GameLoader {
+                /// <summary>
+                /// Called at the end of the game loading thread, <see cref="GameLoader.LoadThread()"/>.<br/>
+                /// In particular, it is called just before stopping the load timer and setting <c>loaded = true</c>.
+                /// This event is invoked <b>only once</b>, when starting the game.
+                /// </summary>
+                public static event Action OnLoadThread;
+                internal static void LoadThread()
+                    => OnLoadThread?.Invoke();
+            }
+
             public static class LevelLoader {
                 public delegate void LoadingThreadHandler(_Level level);
                 /// <summary>

Celeste.Mod.mm/Patches/GameLoader.cs

@@ -121,9 +121,12 @@ private void LoadThread() {
             Console.WriteLine(" - FASTTEXTURELOADING LOAD: " + timer.ElapsedMilliseconds + "ms");
             timer.Stop();
 
+            Everest.Events.GameLoader.LoadThread();
+
             Console.WriteLine("DONE LOADING (in " + Celeste.LoadTimer.ElapsedMilliseconds + "ms)");
             Celeste.LoadTimer.Stop();
             Celeste.LoadTimer = null;
+
             loaded = true;
         }