Simplify SceneManager initial scene logic

src/main/java/org/hirw/game/Scene.java

@@ -1,15 +1,19 @@
 package org.hirw.game;
 
-public abstract class Scene {
-  public final SceneType SCENE_TYPE = SceneType.UNDEFINED;
+import lombok.Getter;
 
-  public Scene() {}
+public abstract class Scene {
+  @Getter private final SceneType sceneType;
+
+  public Scene(SceneType sceneType) {
+    this.sceneType = sceneType;
+  }
 
   public abstract void init();
 
   public abstract void update();
 
   public String toString() {
-    return SCENE_TYPE.toString();
+    return getSceneType().toString();
   }
 }

src/main/java/org/hirw/game/SceneManager.java

@@ -15,32 +15,42 @@ public final class SceneManager {
               SceneType.MENU, new SplashScene(),
               SceneType.GAME, new SplashScene()));
 
-  @Getter private static Scene scene = SCENES.get(DEFAULT_SCENE_TYPE);
+  @Getter private static Scene scene;
 
   public static void init() {
     setScene(DEFAULT_SCENE_TYPE);
   }
 
   public static void setScene(SceneType sceneType) {
-    scene = SCENES.get(sceneType);
+    Scene newScene = SCENES.get(sceneType);
+
+    if (scene == newScene) {
+      Log.warning("SceneManager", sameSceneWarningString());
+      return;
+    } else {
+      scene = newScene;
+    }
+
     scene.init();
     logSceneChange();
   }
 
   public static void update() {
-    if (scene.SCENE_TYPE == SceneType.UNDEFINED) return;
+    if (scene.getSceneType() == null) return;
 
     getScene().update();
   }
 
   private static void logSceneChange() {
-    SceneType newSceneType = getScene().SCENE_TYPE;
+    SceneType newSceneType = getScene().getSceneType();
     String loadedSceneMessage = String.format("Changed to scene '%s'", newSceneType.toString());
 
-    if (newSceneType == SceneType.UNDEFINED) {
-      Log.warning("SceneManager", loadedSceneMessage);
-    } else {
-      Log.success("SceneManager", loadedSceneMessage);
-    }
+    Log.success("SceneManager", loadedSceneMessage);
+  }
+
+  private static String sameSceneWarningString() {
+    return String.format(
+        "Tried to switch to scene '%s' but that scene is already loaded",
+        scene.getSceneType().toString());
   }
 }

src/main/java/org/hirw/game/SceneType.java

@@ -1,7 +1,6 @@
 package org.hirw.game;
 
 public enum SceneType {
-  UNDEFINED,
   SPLASH,
   MENU,
   GAME,