Start and Stop script runtime for editor scene

GlitchyEditor/src/EditorLayer.bf

@@ -864,6 +864,8 @@ namespace GlitchyEditor
 		/// Starts the play mode for the current scene
 		private void OnScenePlay()
 		{
+			// TODO: Dictionary<UUID, ScriptData> scriptData = _editorScene.SerializeScripts();
+
 			_editor.SceneViewportWindow.EditorMode = false;
 			_sceneState = .Play;
 
@@ -871,9 +873,9 @@ namespace GlitchyEditor
 			{
 				_editorScene.CopyTo(runtimeScene, true);
 
-				runtimeScene.OnRuntimeStart();
+				SetActiveScene(runtimeScene, startRuntime: true, startSimulation: true);
 
-				SetReference!(_activeScene, runtimeScene);
+				// TODO: runtimeScene.DeserializeScripts(scriptData);
 			}
 
 			_editor.CurrentScene = _activeScene;
@@ -882,6 +884,27 @@ namespace GlitchyEditor
 				SwitchToPlayWindow();
 		}
 
+		/// Activates the given scene.
+		/// @param scene The scene to be activated.
+		/// @param startRuntime If set to true, the script runtime will be initialized for the given scene.
+		/// @param startSimulation If set to true, the physics simulation will be initialized for the given scene.
+		private void SetActiveScene(Scene scene, bool startRuntime, bool startSimulation)
+		{
+			_activeScene?.StopRuntime();
+			_activeScene?.StopSimulation();
+
+			if (scene != null)
+			{
+				if (startRuntime)
+					scene.StartRuntime();
+	
+				if (startSimulation)
+					scene.StartSimulation();
+			}
+
+			SetReference!(_activeScene, scene);
+		}
+
 		/// Starts the physics simulation mode for the current scene
 		private void OnSceneSimulate()
 		{
@@ -892,9 +915,7 @@ namespace GlitchyEditor
 			{
 				_editorScene.CopyTo(simulationScene, false);
 
-				simulationScene.OnSimulationStart();
-
-				SetReference!(_activeScene, simulationScene);
+				SetActiveScene(simulationScene, startRuntime: false, startSimulation: true);
 			}
 
 			_editor.CurrentScene = _activeScene;
@@ -930,12 +951,9 @@ namespace GlitchyEditor
 		/// Stops the simulation or game and returns to edit mode.
 		private void OnSceneStop()
 		{
-			if (_sceneState == .Play)
-				_activeScene.OnRuntimeStop();
-			else if (_sceneState == .Simulate)
-				_activeScene.OnSimulationStop();
+			SetActiveScene(_editorScene, startRuntime: true, startSimulation: false);
 
-			SetReference!(_activeScene, _editorScene);
+			// TODO: _editorScene.DeserializeScripts(scriptData);
 
 			_editor.SceneViewportWindow.EditorMode = true;
 			_sceneState = .Edit;
@@ -985,9 +1003,19 @@ namespace GlitchyEditor
 		/// Sets the current editor scene
 		private void SetEditorScene(Scene scene)
 		{
+			if (_editorScene != null)
+			{
+				_editorScene.StopRuntime();
+			}
+
 			SetReference!(_editorScene, scene);
 			_editor.CurrentScene = _editorScene;
 			SetReference!(_activeScene, _editorScene);
+
+			if (_editorScene != null)
+			{
+				_editorScene.StartRuntime();
+			}
 		}
 
 		/// Creates a new default scene.

GlitchyEngine/src/Scripting/ScriptEngine.bf

@@ -83,7 +83,12 @@ static class ScriptEngine
 	public static Dictionary<StringView, ScriptClass> EntityClasses => _entityScripts;
 	public static Dictionary<StringView, ScriptClass> ComponentClasses => _componentClasses;
 
-	public static Scene Context => s_Context;
+	/// Gets or sets the current scene context for the runtime.
+	public static Scene Context
+	{
+		get => s_Context;
+		private set => SetReference!(s_Context, value);
+	}
 
 	private static Dictionary<UUID, ScriptFieldMap> _entityFields = new .() ~
 		{
@@ -246,20 +251,38 @@ static class ScriptEngine
 		InitAssemblyWatcher();
 	}
 
-	public static void SetContext(Scene scene)
+	/// Starts the script runtime and sets the context scene.
+	public static void StartRuntime(Scene context)
 	{
-		SetReference!(s_Context, scene);
+		/// At the moment only set the context.
+
+		Debug.Assert(s_Context == null, "StartRuntime was called twice without StopRuntime in between!");
+		Context = context;
 	}
 
-	public static void OnRuntimeStop()
+	/// Stopts the script runtime and disposes of all script instances.
+	public static void StopRuntime()
 	{
-		for (var entry in _entityScriptInstances)
+		if (Context == null)
 		{
-			entry.value?.ReleaseRef();
+			// There should be nothing to do, if we have no context
+			Debug.Assert(_entityScriptInstances.Count == 0, "There are script instances but no context scene.");
+			return;
+		}
+
+		for (let (id, instance) in _entityScriptInstances)
+		{
+			instance?.ReleaseRef();
+
+			Entity entity = Context.GetEntityByID(id);
+
+			// Remove Instance from script
+			ScriptComponent* script = entity.GetComponent<ScriptComponent>();
+			script.Instance = null;
 		}
 		_entityScriptInstances.Clear();
 
-		SetContext(null);
+		Context = null;
 	}
 
 	public static bool InitializeInstance(Entity entity, ScriptComponent* script)

GlitchyEngine/src/World/Scene.bf

@@ -104,8 +104,11 @@ namespace GlitchyEngine.World
 
 		/// Copies all entities with their components to the given target-scene.
 		/// @param target The scene that the entities are copied to.
-		/// @param initializeScripts If true script instances will be initialized.
-		public void CopyTo(Scene target, bool initializeScripts)
+		/// @param copyScripts If true script components will be copied. 
+		///			This is for simulation mode, where the script-components won't be executing, thus we don't copy them.
+		///			TODO: But in reality we still might want to have scripts, because the user might want to run some code, just not OnCreate/OnUpdate?
+		///			TODO: Honestly, I'm not quite sure what simulation mode is actually good for. Maybe we better just remove it?
+		public void CopyTo(Scene target, bool copyScripts)
 		{
 			// Copy entities
 			for (let sourceHandle in _ecsWorld.Enumerate())
@@ -125,43 +128,21 @@ namespace GlitchyEngine.World
 			CopyComponents<CameraComponent>(this, target);
 			CopyComponents<LightComponent>(this, target);
 		
-		
 			CopyComponents<Rigidbody2DComponent>(this, target);
 			CopyComponents<BoxCollider2DComponent>(this, target);
 			CopyComponents<CircleCollider2DComponent>(this, target);
 			CopyComponents<PolygonCollider2DComponent>(this, target);
 
-			if (initializeScripts)
+			if (copyScripts)
 			{
-				// Set context, so that constructors can correctly reference the scene
-				ScriptEngine.SetContext(target);
-
-				//CopyComponents<NativeScriptComponent>(this, target);
-
-				// Copy ScriptComponents... needs extra handling for the script instances
-				for (let (sourceHandle, sourceComponent) in _ecsWorld.Enumerate<ScriptComponent>())
+				for (let (sourceHandle, sourceScript) in _ecsWorld.Enumerate<ScriptComponent>())
 				{
-					Entity sourceEntity = .(sourceHandle, this);
+					Entity sourceEntity = .(sourceHandle, target);
 
 					Entity targetEntity = target.GetEntityByID(sourceEntity.UUID);
-					ScriptComponent* targetComponent = targetEntity.AddComponent<ScriptComponent>();
+					ScriptComponent* targetScript = targetEntity.AddComponent<ScriptComponent>();
 
-					targetComponent.ScriptClassName = sourceComponent.ScriptClassName;
-
-					// Initializes the created instance
-					// TODO: this returns false, if no script with ScriptClassName exists, we have to handle this case correctly I think.
-					ScriptEngine.InitializeInstance(targetEntity, targetComponent);
-				}
-
-				// Copy values to entities.
-				// We do this in a separate loop because we might reference other entities.
-				// If we did it in a single loop these entities might not exist yet.
-				for (let (handle, script) in target._ecsWorld.Enumerate<ScriptComponent>())
-				{
-					Entity entity = .(handle, this);
-
-					if (script.Instance != null)
-						ScriptEngine.CopyEditorFieldsToInstance(entity, script);
+					targetScript.ScriptClassName = sourceScript.ScriptClassName;
 				}
 			}
 
@@ -221,21 +202,36 @@ namespace GlitchyEngine.World
 			}
 		}
 
-		public void OnRuntimeStart()
+		public void Start(bool simulation, bool runtime)
 		{
-			OnSimulationStart();
-			SetupPhysicsCallbacks();
-			ScriptEngine.SetContext(this);
+			if (simulation)
+				StartSimulation();
+
+			
 		}
 
-		public void OnRuntimeStop()
+		public void StartRuntime()
 		{
-			OnSimulationStop();
-			ScriptEngine.OnRuntimeStop();
+			ScriptEngine.StartRuntime(this);
+
+			// Initialize ScriptComponents
+			for (let (handle, scriptComponent) in _ecsWorld.Enumerate<ScriptComponent>())
+			{
+				Entity entity = .(handle, this);
+				// TODO: this returns false, if no script with ScriptClassName exists, we have to handle this case correctly
+				ScriptEngine.InitializeInstance(entity, scriptComponent);
+			}
 		}
 
-		public void OnSimulationStart()
+		public void StopRuntime()
 		{
+			ScriptEngine.StopRuntime();
+		}
+
+		public void StartSimulation()
+		{
+			// TODO: Add Setting for the user to define whether Physics will be initialized or not?
+			
 			_physicsWorld2D = World.Create(_gravity2D);
 
 			draw.drawPolygonCallback = (vertices, vertexCount, color, userData) =>
@@ -289,6 +285,8 @@ namespace GlitchyEngine.World
 			World.SetDebugDrawFlags(_physicsWorld2D, .e_shapeBit);
 
 			InitPhysics2D();
+			
+			SetupPhysicsCallbacks();
 		}
 
 		private void SetupPhysicsCallbacks()
@@ -590,10 +588,15 @@ namespace GlitchyEngine.World
 			polygonCollider.RuntimeFixture = fixture;
 		}
 
-		public void OnSimulationStop()
+		public void StopSimulation()
 		{
+			if (_physicsWorld2D == null)
+				return;
+
 			Box2D.World.Delete(_physicsWorld2D);
 			_physicsWorld2D = null;
+
+			// TODO: Get rid of all references to colliders, etc. in physics components.
 		}
 
 		public enum UpdateMode