Allow dragging and dropping of Entities in editor

+ New Dictionary Helpers
+ Made ImGui Payloads safer
+ Start of Component drag'n'drop

GlitchyEditor/SandboxProject/Assets/Scripts/MyTestEntity.cs

@@ -25,36 +25,36 @@ namespace Sandbox
 
     class MyTestEntity : Entity
     {
-        //[ShowInEditor]
+        [ShowInEditor]
         RigidBody2D _rigidBody;
 
-        public bool Bo;
+        //public bool Bo;
 
-        public byte By;
+        //public byte By;
-        public ushort Us;
+        //public ushort Us;
-        public uint Ui;
+        //public uint Ui;
-        public ulong Ul;
+        //public ulong Ul;
 
-        public sbyte Sb;
+        //public sbyte Sb;
-        public short Sh;
+        //public short Sh;
-        public int In;
+        //public int In;
-        public long Lo;
+        //public long Lo;
 
-        public float Fl;
+        //public float Fl;
-        public double Do;
+        //public double Do;
-        public float2 V2;
+        //public float2 V2;
-        public float3 V3;
+        //public float3 V3;
-        public float4 V4;
+        //public float4 V4;
 
         public Entity TheEntity;
 
         public float JumpForce = 2000;
         [ShowInEditor] float MoveForce = 1000;
         [ShowInEditor] private int MyNumber = 1337;
-        [ShowInEditor] public double MyDouble = 1000.0f;
+        //[ShowInEditor] public double MyDouble = 1000.0f;
-
-        public MyStruct AStruct;
 
+        //public MyStruct AStruct;
+        
         public Camera Camera;
 
         /// <summary>
@@ -67,12 +67,16 @@ namespace Sandbox
             Log.Info($"Jump Force: {JumpForce}");
 
             _rigidBody ??= GetComponent<RigidBody2D>() ?? AddComponent<RigidBody2D>();
-
+            
-            Camera = FindEntityWithName("Camera").As<Camera>();
-
             if (Camera == null)
             {
-                Log.Error("Camera not found.");
+                Log.Warning("Camera wasn't set in editor. Searching...");
+                Camera = FindEntityWithName("Camera").As<Camera>();
+                
+                if (Camera == null)
+                {
+                    Log.Error("Camera not found.");
+                }
             }
         }
 
@@ -99,7 +103,7 @@ namespace Sandbox
 
             if (Input.IsKeyPressed(Key.E))
                 Camera.DistanceFromPlayer += deltaTime;
-
+            
             if (Input.IsKeyPressing(Key.Space))
             {
                 force.Y += JumpForce;

GlitchyEditor/content/Scenes/physics2D.scene

@@ -71,8 +71,8 @@
 			SpriteRendererComponent = {
 				Color = {
 					R = 1,
-					G = 0.941886961,
+					G = 0.941887021,
-					B = 0.401484549,
+					B = 0.401484519,
 					A = 1
 				},
 				Sprite = "",
@@ -162,7 +162,7 @@
 				OrthographicHeight = 10,
 				OrthographicNearPlane = 0,
 				OrthographicFarPlane = 10,
-				AspectRatio = 0.884925187,
+				AspectRatio = 1.17151165,
 				FixedAspectRatio = false
 			},
 			ScriptComponent = {
@@ -195,8 +195,8 @@
 			},
 			TransformComponent = {
 				Position = {
-					X = -0.121203184,
+					X = -0.121203199,
-					Y = 0.660160959,
+					Y = 0.660161018,
 					Z = 0
 				},
 				Rotation = {
@@ -234,37 +234,12 @@
 			ScriptComponent = {
 				ScriptClass = "Sandbox.MyTestEntity",
 				Fields = [
-					Bo = (Bool)false,
+					_rigidBody = (Component)0,
-					By = (Byte)0,
-					Us = (UShort)57,
-					Ui = (UInt)54,
-					Ul = (ULong)53,
-					Sb = (SByte)-128,
-					Sh = (Short)95,
-					In = (Int)-149,
-					Lo = (Long)82,
-					Fl = (Float)-98.122963,
-					Do = (Double)118,
-					V2 = (float2){
-						X = 11,
-						Y = 12
-					},
-					V3 = (float3){
-						X = 13,
-						Y = 14,
-						Z = 15
-					},
-					V4 = (float4){
-						X = 14,
-						Y = 17,
-						Z = 18,
-						W = 19
-					},
 					TheEntity = (Entity)0,
 					JumpForce = (Float)200,
 					MoveForce = (Float)148,
 					MyNumber = (Int)22,
-					MyDouble = (Double)23
+					Camera = (Entity)1491484622542812645
 				]			}
 		},
 		{
@@ -301,7 +276,7 @@
 				Color = {
 					R = 0.985467017,
 					G = 1,
-					B = 0.569978058
+					B = 0.569977999
 				}
 			}
 		},
@@ -348,8 +323,8 @@
 			SpriteRendererComponent = {
 				Color = {
 					R = 0.425658971,
-					G = 0.855207562,
+					G = 0.855207503,
-					B = 0.0558161102,
+					B = 0.0558161139,
 					A = 1
 				},
 				Sprite = "",
@@ -363,14 +338,14 @@
 			TransformComponent = {
 				Position = {
 					X = 6.74610233,
-					Y = -2.03225899,
+					Y = -2.03225923,
 					Z = 0
 				},
 				Rotation = {
 					X = 0,
 					Y = 0,
 					Z = -0.331792623,
-					W = 0.943352342
+					W = 0.943352461
 				},
 				Scale = {
 					X = 5.29557419,
@@ -409,7 +384,7 @@
 			},
 			SpriteRendererComponent = {
 				Color = {
-					R = 0.666116953,
+					R = 0.666117013,
 					G = 0.0600316115,
 					B = 1,
 					A = 1
@@ -424,8 +399,8 @@
 			},
 			TransformComponent = {
 				Position = {
-					X = 15.2321301,
+					X = 15.2321291,
-					Y = -1.98709249,
+					Y = -1.98709261,
 					Z = 0
 				},
 				Rotation = {
@@ -435,7 +410,7 @@
 					W = 0.990847468
 				},
 				Scale = {
-					X = 13.9764566,
+					X = 13.9764547,
 					Y = 1,
 					Z = 1
 				},
@@ -471,7 +446,7 @@
 			},
 			SpriteRendererComponent = {
 				Color = {
-					R = 0.176544324,
+					R = 0.176544309,
 					G = 0.666713238,
 					B = 0.687030852,
 					A = 1
@@ -487,24 +462,24 @@
 			TransformComponent = {
 				Position = {
 					X = -6.27842855,
-					Y = 2.62550211,
+					Y = 2.62550187,
 					Z = 0
 				},
 				Rotation = {
 					X = 0,
 					Y = 0,
-					Z = 0.187087834,
+					Z = 0.187087849,
 					W = 0.982343197
 				},
 				Scale = {
-					X = 0.999999523,
+					X = 0.999999464,
 					Y = 6.49634314,
 					Z = 1
 				},
 				EditorEulerRotation = {
 					X = 0,
 					Y = 0,
-					Z = 0.376393586
+					Z = 0.376393616
 				}
 			},
 			Rigidbody2D = {
@@ -522,7 +497,7 @@
 				},
 				Density = 1,
 				Friction = 0.5,
-				Restitution = 0.899999976,
+				Restitution = 0.899999917,
 				RestitutionThreshold = 0.5
 			}
 		}

GlitchyEditor/resources/scripts/ScriptCore.deps.json

@@ -9,12 +9,21 @@
     ".NETStandard,Version=v2.0/": {
       "ScriptCore/1.0.0": {
         "dependencies": {
+          "Half": "1.0.0",
           "NETStandard.Library": "2.0.3"
         },
         "runtime": {
           "ScriptCore.dll": {}
         }
       },
+      "Half/1.0.0": {
+        "runtime": {
+          "lib/netstandard2.0/System.Half.dll": {
+            "assemblyVersion": "1.0.0.0",
+            "fileVersion": "1.0.0.0"
+          }
+        }
+      },
       "Microsoft.NETCore.Platforms/1.1.0": {},
       "NETStandard.Library/2.0.3": {
         "dependencies": {
@@ -29,6 +38,13 @@
       "serviceable": false,
       "sha512": ""
     },
+    "Half/1.0.0": {
+      "type": "package",
+      "serviceable": true,
+      "sha512": "sha512-EPLLPQA1UjF9QM3ymNhWLhgcnBNc8e1po4qWRWTD3Hd9xiohYlkCob0QjDIbJs6Nvfd4eAbsjxIwRyh7httyXA==",
+      "path": "half/1.0.0",
+      "hashPath": "half.1.0.0.nupkg.sha512"
+    },
     "Microsoft.NETCore.Platforms/1.1.0": {
       "type": "package",
       "serviceable": true,

GlitchyEditor/src/Assets/MaterialAssetLoader.bf

@@ -33,7 +33,7 @@ class MaterialAssetPropertiesEditor : AssetPropertiesEditor
 
 		if (ImGui.BeginDragDropTarget())
 		{
-			ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+			ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 			
 			if (payload != null)
 			{
@@ -78,7 +78,7 @@ class MaterialAssetPropertiesEditor : AssetPropertiesEditor
 
 			if (ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 
 				if (payload != null)
 				{

GlitchyEditor/src/EditWindows/ComponentEditWindow.bf

@@ -7,6 +7,8 @@ using GlitchyEngine.Renderer;
 using GlitchyEngine;
 using GlitchyEngine.Content;
 using GlitchyEngine.Scripting;
+using GlitchyEngine.Core;
+using Mono;
 
 namespace GlitchyEditor.EditWindows
 {
@@ -278,7 +280,7 @@ namespace GlitchyEditor.EditWindows
 
 			if (ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 
 				if (payload != null)
 				{
@@ -306,7 +308,7 @@ namespace GlitchyEditor.EditWindows
 
 			if (ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 
 				if (payload != null)
 				{
@@ -338,7 +340,7 @@ namespace GlitchyEditor.EditWindows
 
 			if (ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 
 				if (payload != null)
 				{
@@ -601,94 +603,94 @@ namespace GlitchyEditor.EditWindows
 			{
 				let scriptFields = ScriptEngine.GetScriptFieldMap(entity);
 
-				for (var (name, field) in ref scriptFields)
+				for (var (fieldName, field) in ref scriptFields)
 				{
 					switch (field.Type)
 					{
 					case .Bool:
 						var value = field.GetData<bool>();
-						if (ImGui.Checkbox(name.CStr(), &value))
+						if (ImGui.Checkbox(fieldName.CStr(), &value))
 							field.SetData(value);
 
 					case .SByte:
 						var value = field.GetData<int8>();
-						if (ImGui.DragScalar(name.CStr(), .S8, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .S8, &value))
+							field.SetData(value);
+					case .Short:
+						var value = field.GetData<int16>();
+						if (ImGui.DragScalar(fieldName.CStr(), .S16, &value))
 							field.SetData(value);
-						case .Short:
-							var value = field.GetData<int16>();
-							if (ImGui.DragScalar(name.CStr(), .S16, &value))
-								field.SetData(value);
 					case .Int:
-							var value = field.GetData<int32>();
+						var value = field.GetData<int32>();
-							if (ImGui.DragScalar(name.CStr(), .S32, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .S32, &value))
-								field.SetData(value);
+							field.SetData(value);
 					case .Int2:
-							var value = field.GetData<int2>();
+						var value = field.GetData<int2>();
-							if (ImGui.DragScalarN(name.CStr(), .S32, &value, 2))
+						if (ImGui.DragScalarN(fieldName.CStr(), .S32, &value, 2))
-								field.SetData(value);
+							field.SetData(value);
 					case .Int3:
-							var value = field.GetData<int3>();
+						var value = field.GetData<int3>();
-							if (ImGui.DragScalarN(name.CStr(), .S32, &value, 3))
+						if (ImGui.DragScalarN(fieldName.CStr(), .S32, &value, 3))
-								field.SetData(value);
+							field.SetData(value);
 					case .Int4:
-							var value = field.GetData<int4>();
+						var value = field.GetData<int4>();
-							if (ImGui.DragScalarN(name.CStr(), .S32, &value, 4))
+						if (ImGui.DragScalarN(fieldName.CStr(), .S32, &value, 4))
-								field.SetData(value);
+							field.SetData(value);
 					case .Long:
-							var value = field.GetData<int64>();
+						var value = field.GetData<int64>();
-							if (ImGui.DragScalar(name.CStr(), .S64, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .S64, &value))
-								field.SetData(value);
+							field.SetData(value);
 
 					case .Byte:
-							var value = field.GetData<uint8>();
+						var value = field.GetData<uint8>();
-							if (ImGui.DragScalar(name.CStr(), .U8, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .U8, &value))
-								field.SetData(value);
+							field.SetData(value);
 					case .UShort:
-							var value = field.GetData<uint16>();
+						var value = field.GetData<uint16>();
-							if (ImGui.DragScalar(name.CStr(), .U16, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .U16, &value))
-								field.SetData(value);
+							field.SetData(value);
 					case .UInt:
-							var value = field.GetData<uint32>();
+						var value = field.GetData<uint32>();
-							if (ImGui.DragScalar(name.CStr(), .U32, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .U32, &value))
-								field.SetData(value);
+							field.SetData(value);
 					case .ULong:
-							var value = field.GetData<uint64>();
+						var value = field.GetData<uint64>();
-							if (ImGui.DragScalar(name.CStr(), .U64, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .U64, &value))
-								field.SetData(value);
+							field.SetData(value);
 
 					case .Float:
-							var value = field.GetData<float>();
+						var value = field.GetData<float>();
-							if (ImGui.DragScalar(name.CStr(), .Float, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .Float, &value))
-								field.SetData(value);
+							field.SetData(value);
 					case .float2:
-							var value = field.GetData<float2>();
+						var value = field.GetData<float2>();
-							if (ImGui.Editfloat2(name, ref value))
+						if (ImGui.Editfloat2(fieldName, ref value))
-								field.SetData(value);
+							field.SetData(value);
 					case .float3:
-							var value = field.GetData<float3>();
+						var value = field.GetData<float3>();
-							if (ImGui.Editfloat3(name, ref value))
+						if (ImGui.Editfloat3(fieldName, ref value))
-								field.SetData(value);
+							field.SetData(value);
 					case .float4:
-							var value = field.GetData<float4>();
+						var value = field.GetData<float4>();
-							if (ImGui.Editfloat4(name, ref value))
+						if (ImGui.Editfloat4(fieldName, ref value))
-								field.SetData(value);
+							field.SetData(value);
 
 					case .Double:
-							var value = field.GetData<double>();
+						var value = field.GetData<double>();
-							if (ImGui.DragScalar(name.CStr(), .Double, &value))
+						if (ImGui.DragScalar(fieldName.CStr(), .Double, &value))
-								field.SetData(value);
+							field.SetData(value);
 					case .Double2:
-							var value = field.GetData<double2>();
+						var value = field.GetData<double2>();
-							if (ImGui.DragScalarN(name.CStr(), .Double, &value, 2))
+						if (ImGui.DragScalarN(fieldName.CStr(), .Double, &value, 2))
-								field.SetData(value);
+							field.SetData(value);
 					case .Double3:
-							var value = field.GetData<double3>();
+						var value = field.GetData<double3>();
-							if (ImGui.DragScalarN(name.CStr(), .Double, &value, 3))
+						if (ImGui.DragScalarN(fieldName.CStr(), .Double, &value, 3))
-								field.SetData(value);
+							field.SetData(value);
 					case .Double4:
-							var value = field.GetData<double4>();
+						var value = field.GetData<double4>();
-							if (ImGui.DragScalarN(name.CStr(), .Double, &value, 4))
+						if (ImGui.DragScalarN(fieldName.CStr(), .Double, &value, 4))
-								field.SetData(value);
+							field.SetData(value);
 
 					case .Enum:
 						// TODO!
@@ -697,11 +699,16 @@ namespace GlitchyEditor.EditWindows
 						// TODO!
 
 					case .Entity:
-						// TODO!
+						ShowEntityReceiver(field, fieldName, scriptClass);
+					case .Component:
+						ShowComponentReceiver(field, fieldName, scriptClass);
 
 					case .Struct:
 						// TODO!
 
+					case .Class:
+						// We don't support editing classes
+
 					default:
 						Log.EngineLogger.Error($"Unhandled field type {field.Type}");
 					}
@@ -709,6 +716,133 @@ namespace GlitchyEditor.EditWindows
 			}
 		}
 
+		private static void ShowEntityReceiver(ScriptFieldInstance* field, StringView fieldName, ScriptClass scriptClass)
+		{
+			var entityId = field.GetData<UUID>();
+
+			Result<Entity> fieldEntity = Editor.Instance.CurrentScene.GetEntityByID(entityId);
+
+			String entityName = scope .(32);
+
+			if (fieldEntity case .Ok(Entity e))
+				entityName.Set(e.Name);
+			else
+				entityName..Clear().AppendF($"Missing entity ({entityId})");
+
+			ImGui.Text($"{fieldName}: ");
+			ImGui.SameLine();
+
+			if (ImGui.Button(entityName))
+			{
+				// TODO: Show a selector or something
+			}
+
+			if (ImGui.BeginDragDropTarget())
+			{
+				ImGui.Payload* peekPayload = ImGui.AcceptDragDropPayload(.Entity, .AcceptPeekOnly);
+
+				bool allowDrop = false;
+
+				if (peekPayload != null)
+				{
+					Entity draggedEntity = *(Entity*)peekPayload.Data;
+
+					ScriptClass draggedScriptClass = ScriptEngine.[Friend]s_EntityRoot;
+
+					if (draggedEntity.TryGetComponent<ScriptComponent>(let draggedScript))
+					{
+						var draggedClassName = draggedScript.ScriptClassName;
+						draggedScriptClass = ScriptEngine.GetScriptClass(draggedClassName);
+
+					}
+
+					// TODO: I don't like the fact, that we are using mono directly
+
+					ScriptField scriptField = scriptClass.Fields[fieldName];
+					var fieldMonoClass = Mono.mono_type_get_class(scriptField.GetMonoType());
+
+					allowDrop = draggedScriptClass.[Friend]IsSubclass(fieldMonoClass);
+				}
+
+				if (allowDrop)
+				{
+					ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.Entity);
+
+					if (payload != null)
+					{
+						Log.EngineLogger.AssertDebug(payload.DataSize == sizeof(Entity));
+
+						Entity droppedEntity = *(Entity*)payload.Data;
+
+						if (droppedEntity.IsValid)
+							field.SetData<UUID>(droppedEntity.UUID);
+					}
+				}
+
+				ImGui.EndDragDropTarget();
+			}
+		}
+
+		private static void ShowComponentReceiver(ScriptFieldInstance* field, StringView fieldName, ScriptClass scriptClass)
+		{
+			var entityId = field.GetData<UUID>();
+
+			Result<Entity> fieldEntity = Editor.Instance.CurrentScene.GetEntityByID(entityId);
+
+			String entityName = scope .(32);
+
+			if (fieldEntity case .Ok(Entity e))
+				entityName.Set(e.Name);
+			else
+				entityName..Clear().AppendF($"Missing reference ({entityId})");
+
+			ImGui.Text($"{fieldName}: ");
+			ImGui.SameLine();
+
+			if (ImGui.Button(entityName))
+			{
+				// TODO: Show a selector or something
+			}
+
+			if (ImGui.BeginDragDropTarget())
+			{
+				ImGui.Payload* peekPayload = ImGui.AcceptDragDropPayload(.Entity, .AcceptPeekOnly);
+
+				bool allowDrop = false;
+
+				if (peekPayload != null)
+				{
+					Entity draggedEntity = *(Entity*)peekPayload.Data;
+
+					// TODO: I don't like the fact, that we are using mono directly
+
+					ScriptField scriptField = scriptClass.Fields[fieldName];
+					MonoReflectionType* reflectionType = Mono.mono_type_get_object(ScriptEngine.[Friend]s_AppDomain, scriptField.GetMonoType());
+
+					// TODO: We shouldn't abuse the script glue like that...
+					// ScriptGlue should only be called by C#, not by Beef...
+					allowDrop = ScriptGlue.[Friend]Entity_HasComponent(draggedEntity.UUID, reflectionType);
+				}
+
+				if (allowDrop)
+				{
+					ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.Entity);
+
+					if (payload != null)
+					{
+						Log.EngineLogger.AssertDebug(payload.DataSize == sizeof(Entity));
+
+						Entity droppedEntity = *(Entity*)payload.Data;
+
+						if (droppedEntity.IsValid)
+							field.SetData<UUID>(droppedEntity.UUID);
+					}
+				}
+
+				ImGui.EndDragDropTarget();
+			}
+		}
+
 		private static void LabelColumn(StringView label)
 		{
 			ImGui.TextUnformatted(label);
@@ -773,7 +907,7 @@ namespace GlitchyEditor.EditWindows
 
 			if (ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 
 				if (payload != null)
 				{

GlitchyEditor/src/EditWindows/ContentBrowserWindow.bf

@@ -324,7 +324,7 @@ namespace GlitchyEditor.EditWindows
 
 				Path.Fixup(fullpath);
 
-				ImGui.SetDragDropPayload("CONTENT_BROWSER_ITEM", fullpath.CStr(), (.)fullpath.Length, .Once);
+				ImGui.SetDragDropPayload(.ContentBrowserItem, fullpath.CStr(), (.)fullpath.Length, .Once);
 
 				ImGui.EndDragDropSource();
 			}
@@ -370,7 +370,7 @@ namespace GlitchyEditor.EditWindows
 						String fullpath = scope String(entry->Path);
 						fullpath.AppendF($"#{subAsset.Name}");
 
-						ImGui.SetDragDropPayload("CONTENT_BROWSER_ITEM", fullpath.CStr(), (.)fullpath.Length, .Once);
+						ImGui.SetDragDropPayload(.ContentBrowserItem, fullpath.CStr(), (.)fullpath.Length, .Once);
 		
 						ImGui.EndDragDropSource();
 					}

GlitchyEditor/src/EditWindows/EditorViewportWindow.bf

@@ -137,7 +137,7 @@ namespace GlitchyEditor.EditWindows
 		{
 			if (ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 
 				if (payload != null)
 				{

GlitchyEditor/src/EditWindows/EntityHierarchyWindow.bf

@@ -341,9 +341,13 @@ namespace GlitchyEditor.EditWindows
 			if (deleted)
 				return;
 
+			bool isDragged = false;
+
 			if(ImGui.BeginDragDropSource())
 			{
-				ImGui.SetDragDropPayload("DND_Entity", &tree.Value, sizeof(Entity));
+				isDragged = true;
+
+				ImGui.SetDragDropPayload(.Entity, &tree.Value, sizeof(Entity));
 
 				ImGui.Text(name);
 
@@ -352,7 +356,7 @@ namespace GlitchyEditor.EditWindows
 
 			if(ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("DND_Entity");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.Entity);
 
 				if(payload != null)
 				{
@@ -395,7 +399,7 @@ namespace GlitchyEditor.EditWindows
 
 			bool clicked = ImGui.IsItemClicked(.Left);
 			bool clickedRight = ImGui.IsItemClicked(.Right);
-
+			
 			if(isOpen)
 			{
 				for(var child in tree.Children)
@@ -407,6 +411,12 @@ namespace GlitchyEditor.EditWindows
 			}
 
 			if (clicked || clickedRight)
+			{
+				lastClickedEntity = tree.Value;
+			}
+
+			//if (!isDragged && (clicked || clickedRight))
+			if (!isDragged && (!ImGui.IsMouseDown(.Left) && !ImGui.IsMouseDown(.Right) && ImGui.IsItemHovered()) && tree.Value == lastClickedEntity)
 			{
 				if (inSelectedList && !clickedRight)
 				{
@@ -418,9 +428,13 @@ namespace GlitchyEditor.EditWindows
 					SelectEntity(tree.Value, !ImGui.GetIO().KeyCtrl && !clickedRight);
 					inSelectedList = true;
 				}
+
+				lastClickedEntity = .();
 			}
 		}
 
+		private static Entity lastClickedEntity;
+
 		private void ShowEntityHierarchy()
 		{
 			StringView searchString = StringView(&_entitySearchChars);
@@ -464,7 +478,7 @@ namespace GlitchyEditor.EditWindows
 				{
 					if(ImGui.BeginDragDropTarget())
 					{
-						ImGui.Payload* payload = ImGui.AcceptDragDropPayload("DND_Entity");
+						ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.Entity);
 
 						if(payload != null)
 						{
@@ -527,6 +541,10 @@ namespace GlitchyEditor.EditWindows
 					ImGuiPrintEntityTree(scope .(entity));
 				}
 			}
+
+			// If the mouse was released and no entity took the chance to become selected we probably hovered the background while releasing -> select no entity
+			if (!ImGui.IsMouseDown(.Left) && !ImGui.IsMouseDown(.Right))
+				lastClickedEntity = .();
 		}
 	}
 }

GlitchyEditor/src/EditWindows/GameViewportWindow.bf

@@ -91,7 +91,7 @@ namespace GlitchyEditor.EditWindows
 		{
 			if (ImGui.BeginDragDropTarget())
 			{
-				ImGui.Payload* payload = ImGui.AcceptDragDropPayload("CONTENT_BROWSER_ITEM");
+				ImGui.Payload* payload = ImGui.AcceptDragDropPayload(.ContentBrowserItem);
 
 				if (payload != null)
 				{

GlitchyEditor/src/Editor.bf

@@ -53,9 +53,16 @@ namespace GlitchyEditor
 		public SceneRenderer GameSceneRenderer {get; set;}
 		public SceneRenderer EditorSceneRenderer {get; set;}
 
+		private static Editor s_Instance;
+
+		public static Editor Instance => s_Instance;
+
 		/// Creates a new editor for the given world
 		public this(Scene scene, EditorContentManager contentManager)
 		{
+			Log.EngineLogger.AssertDebug(s_Instance == null, "Cannot create a second instance of a singleton.");
+			s_Instance = this;
+
 			_scene = scene;
 			_contentManager = contentManager;
 

GlitchyEditor/src/ImGuiExtension.bf

@@ -0,0 +1,33 @@
+using System;
+
+namespace ImGui;
+
+enum DragDropPayloadType
+{
+	case ContentBrowserItem;
+	case Entity;
+
+	public String GetName()
+	{
+		switch (this)
+		{
+		case .ContentBrowserItem:
+			return "CONTENT_BROWSER_ITEM";
+		case .Entity:
+			return "ENTITY";
+		}
+	}
+}
+
+extension ImGui
+{
+	public static Payload* AcceptDragDropPayload(DragDropPayloadType type, DragDropFlags flags = .None)
+	{
+		return AcceptDragDropPayload(type.GetName(), flags);
+	}
+
+	public static bool SetDragDropPayload(DragDropPayloadType type, void* data, size sz, Cond cond = .None)
+	{
+		return SetDragDropPayload(type.GetName(), data, sz, cond);
+	}
+}

GlitchyEngine/src/Helper.bf

@@ -70,5 +70,25 @@ namespace GlitchyEngine
 				delete dictionary;
 			}
 		}
+
+		public static mixin ClearDictionaryAndReleaseKeys(var dictionary)
+		{
+			if (dictionary != null)
+			{
+				for (var value in dictionary)
+					value.key?.ReleaseRef();
+				dictionary.Clear();
+			}
+		}
+
+		public static mixin ClearDictionaryAndReleaseValues(var dictionary)
+		{
+			if (dictionary != null)
+			{
+				for (var value in dictionary)
+					value.value?.ReleaseRef();
+				dictionary.Clear();
+			}
+		}
 	}
 }

GlitchyEngine/src/Scripting/ScriptClass.bf

@@ -21,6 +21,33 @@ public struct ScriptField
 		IsStatic = isStatic;
 		FieldType = fieldType;
 	}
+
+	public bool IsType(SharpClass otherClass, bool checkIfSubtype)
+	{
+		return IsType(otherClass.GetMonoType(), checkIfSubtype);
+	}
+
+	public bool IsType(MonoType* otherType, bool checkIfSubtype)
+	{
+		MonoType* myType = GetMonoType();
+
+		if (checkIfSubtype)
+		{
+			MonoClass* myClass = Mono.mono_type_get_class(myType);
+			MonoClass* otherClass = Mono.mono_type_get_class(otherType);
+
+			return Mono.mono_class_is_subclass_of(myClass, otherClass, false);
+		}
+		else
+		{
+			return myType == otherType;
+		}
+	}
+
+	public MonoType* GetMonoType()
+	{
+		return Mono.mono_field_get_type(_monoField);
+	}
 }
 
 public struct ScriptFieldInstance
@@ -90,9 +117,19 @@ class SharpClass : SharpType
 		ExtractFields();
 	}
 
+	internal MonoType* GetMonoType()
+	{
+		return Mono.mono_class_get_type(_monoClass);
+	}
+
 	internal bool IsType(MonoType* type)
 	{
-		return Mono.mono_class_get_type(_monoClass) == type;
+		return GetMonoType() == type;
+	}
+
+	internal bool IsSubclass(MonoClass* @class)
+	{
+		return Mono.mono_class_is_subclass_of(_monoClass, @class, false);
 	}
 
 	private void ExtractFields()
@@ -180,8 +217,8 @@ class ScriptClass : SharpClass
 	public Dictionary<StringView, ScriptField> Fields => _monoFields;*/
 
 	[AllowAppend]
-	public this(StringView classNamespace, StringView className, MonoImage* image) :
+	public this(StringView classNamespace, StringView className, MonoImage* image, ScriptFieldType scriptFieldType = .Class) :
-		base(classNamespace, className, image)
+		base(classNamespace, className, image, scriptFieldType)
 	{
 		//_constructor = (ConstructorMethod)GetMethodThunk(".ctor", 1); // GetMethod(".ctor", 1);//
 		_constructor = GetMethod(".ctor", 1);
@@ -288,6 +325,19 @@ class ScriptClass : SharpClass
 
 	public void SetFieldValue<T>(MonoObject* instance, MonoClassField* field, in T value)
 	{
-		Mono.Mono.mono_field_set_value(instance, field, &value);
+		/*if (typeof(T) == typeof(MonoObject*))
+		{
+			// TODO: MonoObject* is a pointer already, so we don't take the pointer
+			Mono.Mono.mono_field_set_value(instance, field, (void*)value);
+		}
+		else
+		{*/
+			Mono.Mono.mono_field_set_value(instance, field, &value);
+		//}
+	}
+
+	public void SetFieldValue<T>(MonoObject* instance, MonoClassField* field, in T value) where T : struct*
+	{
+		Mono.Mono.mono_field_set_value(instance, field, value);
 	}
 }

GlitchyEngine/src/Scripting/ScriptEngine.bf

@@ -58,12 +58,14 @@ static class ScriptEngine
 
 	private static Scene s_Context ~ _?.ReleaseRef();
 
+	private static ScriptClass s_ComponentRoot ~ _?.ReleaseRef();
 	private static ScriptClass s_EntityRoot ~ _?.ReleaseRef();
 	private static ScriptClass s_EngineObject ~ _?.ReleaseRef();
 
 	private static Dictionary<StringView, SharpType> _sharpClasses = new .() ~ DeleteDictionaryAndReleaseValues!(_);
 	
 	private static Dictionary<StringView, ScriptClass> _entityScripts = new .() ~ DeleteDictionaryAndReleaseValues!(_);
+	private static Dictionary<StringView, ScriptClass> _componentClasses = new .() ~ DeleteDictionaryAndReleaseValues!(_);
 	
 	private static Dictionary<UUID, ScriptInstance> _entityScriptInstances = new .() ~ {
 		for (var entry in _)
@@ -74,6 +76,7 @@ static class ScriptEngine
 	}
 
 	public static Dictionary<StringView, ScriptClass> EntityClasses => _entityScripts;
+	public static Dictionary<StringView, ScriptClass> ComponentClasses => _componentClasses;
 
 	public static Scene Context => s_Context;
 
@@ -170,7 +173,12 @@ static class ScriptEngine
 		CreateAppDomain("GlitchyEngineScriptRuntime");
 		(s_CoreAssembly, s_CoreAssemblyImage) = LoadAssembly("resources/scripts/ScriptCore.dll", _debuggingEnabled);
 		(s_AppAssembly, s_AppAssemblyImage) = LoadAssembly("SandboxProject/Assets/Scripts/bin/Sandbox.dll", _debuggingEnabled);
-
+		
+		ClearDictionaryAndReleaseValues!(_sharpClasses);
+		
+		GetCoreAttributes();
+		GetCoreClasses();
+		
 		GetEntitiesFromAssemblies();
 
 		ScriptGlue.RegisterManagedComponents();
@@ -206,12 +214,12 @@ static class ScriptEngine
 
 		script.Instance.Instantiate(entity.UUID);
 
-		CopyEditorFieldsToInstance(entity, script);
+		//CopyEditorFieldsToInstance(entity, script);
 
 		return true;
 	}
 
-	private static void CopyEditorFieldsToInstance(Entity entity, ScriptComponent* script)
+	public static void CopyEditorFieldsToInstance(Entity entity, ScriptComponent* script)
 	{
 		// Technically the map is for a different entity (namely the editor-entity),
 		// however the UUID is the same, so we get the correct field map
@@ -220,10 +228,24 @@ static class ScriptEngine
 		for (var (fieldName, field) in fields)
 		{
 			// TODO: a litte assertion maybe?
-
+			
 			ScriptField scriptField = script.Instance.ScriptClass.Fields[fieldName];
 
-			script.Instance.SetFieldValue(scriptField, field._data);
+			switch (scriptField.FieldType)
+			{
+			case .Entity:
+				// On the C# side we actually differentiate between an Entity and the Script
+				// in the sense that getting an entity and a script yields two different results (one creates a new Entity-Class instance, the other returns the actual instance).
+				// But here its just easier to always use the script instance.
+				// Obviously breaks once we support multiple scripts per entity.
+				UUID referencedId = field.GetData<UUID>();
+				MonoObject* referencedEntity = GetManagedInstance(referencedId);
+				script.Instance.SetFieldValue(scriptField, referencedEntity);
+			case .Component:
+
+			default:
+				script.Instance.SetFieldValue(scriptField, field._data);
+			}
 		}
 	}
 
@@ -297,32 +319,27 @@ static class ScriptEngine
 		return (assembly, image);
 	}
 
+	/// Retrieves the base classes from which every Component or Entity inherits
+	static void GetCoreClasses()
+	{
+		s_EngineObject?.ReleaseRef();
+		s_EntityRoot?.ReleaseRef();
+		s_ComponentRoot?.ReleaseRef();
+
+		s_EngineObject = new ScriptClass("GlitchyEngine.Core", "EngineObject", s_CoreAssemblyImage, .Class);
+		s_EntityRoot = new ScriptClass("GlitchyEngine", "Entity", s_CoreAssemblyImage, .Entity);
+		s_ComponentRoot = new ScriptClass("GlitchyEngine", "Component", s_CoreAssemblyImage, .Component);
+	}
+	
+	/// Retrieves the classes for Attributes that are defined in the Core library
+	static void GetCoreAttributes()
+	{
+		Attributes.s_ShowInEditorAttribute = Mono.mono_class_from_name(s_CoreAssemblyImage, "GlitchyEngine.Editor", "ShowInEditorAttribute");
+	}
+
 	private static void GetEntitiesFromAssemblies()
 	{
-		for (var entry in _entityScripts)
+		ClearDictionaryAndReleaseValues!(_entityScripts);
-		{
-			entry.value.ReleaseRef();
-		}
-		_entityScripts.Clear();
-
-		for (var sharpClass in _sharpClasses)
-		{
-			sharpClass.value.ReleaseRef();
-		}
-		_sharpClasses.Clear();
-		
-		if (s_EngineObject != null)
-		{
-			s_EngineObject.ReleaseRef();
-			s_EntityRoot.ReleaseRef();
-		}
-
-		s_EngineObject = new ScriptClass("GlitchyEngine.Core", "EngineObject", s_CoreAssemblyImage);
-		s_EntityRoot = new ScriptClass("GlitchyEngine", "Entity", s_CoreAssemblyImage);
-
-		Log.EngineLogger.Assert(s_EntityRoot != null);
-
-		Attributes.s_ShowInEditorAttribute = Mono.mono_class_from_name(s_CoreAssemblyImage, "GlitchyEngine.Editor", "ShowInEditorAttribute");
 
 	    MonoTableInfo* typeDefinitionsTable = Mono.mono_image_get_table_info(s_AppAssemblyImage, .MONO_TABLE_TYPEDEF);
 	    int32 numTypes = Mono.mono_table_info_get_rows(typeDefinitionsTable);
@@ -336,10 +353,19 @@ static class ScriptEngine
 			char8* name = Mono.mono_metadata_string_heap(s_AppAssemblyImage, (.)cols[(.)SOME_RANDOM_ENUM.MONO_TYPEDEF_NAME]);
 			
 			MonoClass* monoClass = Mono.mono_class_from_name(s_AppAssemblyImage, nameSpace, name);
-
+			
+			// Check if it is an entity
 			if (monoClass != null && Mono.mono_class_is_subclass_of(monoClass, s_EntityRoot.[Friend]_monoClass, false))
 			{
-				ScriptClass entityScript = new ScriptClass(StringView(nameSpace), StringView(name), s_AppAssemblyImage);
+				ScriptClass entityScript = new ScriptClass(StringView(nameSpace), StringView(name), s_AppAssemblyImage, .Entity);
+				_entityScripts.Add(entityScript.FullName, entityScript);
+
+				Log.EngineLogger.Info($"Added entity \"{entityScript.FullName}\"");
+			}
+			// Check if it is a component
+			else if (monoClass != null && Mono.mono_class_is_subclass_of(monoClass, s_ComponentRoot.[Friend]_monoClass, false))
+			{
+				ScriptClass entityScript = new ScriptClass(StringView(nameSpace), StringView(name), s_AppAssemblyImage, .Entity);
 				_entityScripts.Add(entityScript.FullName, entityScript);
 
 				Log.EngineLogger.Info($"Added entity \"{entityScript.FullName}\"");
@@ -399,8 +425,8 @@ static class ScriptEngine
 		StringView classNamespace = StringView(Mono.mono_class_get_namespace(monoClass));
 
 		// TODO: at the moment only allow user-structs
-		if (classNamespace.StartsWith("GlitchyEngine"))
+		//if (classNamespace.StartsWith("GlitchyEngine"))
-			return null;
+		//	return null;
 
 		switch (fieldType)
 		{
@@ -408,7 +434,20 @@ static class ScriptEngine
 			ScriptFieldType scriptType = .None;
 
 			if (fieldType == .Class)
-				scriptType = .Class;
+			{
+				if (Mono.mono_class_is_subclass_of(monoClass, s_EntityRoot._monoClass, false))
+				{
+					scriptType = .Entity;
+				}
+				else if (Mono.mono_class_is_subclass_of(monoClass, s_ComponentRoot._monoClass, false))
+				{
+					scriptType = .Component;
+				}
+				else
+				{
+					scriptType = .Class;
+				}
+			}
 			else if (fieldType == .Enum)
 				scriptType = .Enum;
 			else if (fieldType == .Valuetype)

GlitchyEngine/src/Scripting/ScriptFieldType.bf

@@ -27,6 +27,7 @@ enum ScriptFieldType
 	case Double, Double2, Double3, Double4;
 	
 	case Entity;
+	case Component;
 
 	public Type GetBeefType()
 	{
@@ -79,6 +80,8 @@ enum ScriptFieldType
 
 		case .Entity:
 			return typeof(UUID);
+		case .Component:
+			return typeof(UUID);
 
 		default:
 			return null;

GlitchyEngine/src/Scripting/ScriptInstance.bf

@@ -21,6 +21,8 @@ class ScriptInstance : RefCounter
 	
 	private bool _isCreated = false;
 
+	internal MonoObject* MonoInstance => _instance;
+
 	public this(ScriptClass scriptClass)
 	{
 		Log.EngineLogger.AssertDebug(scriptClass != null);
@@ -37,8 +39,6 @@ class ScriptInstance : RefCounter
 		_scriptClass?.ReleaseRef();
 	}
 
-	internal MonoObject* MonoInstance => _instance;
-
 	public void Instantiate(UUID uuid)
 	{
 		_instance = _scriptClass.CreateInstance(uuid);

GlitchyEngine/src/World/Scene.bf

@@ -100,6 +100,15 @@ namespace GlitchyEngine.World
 				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);
+				ScriptEngine.CopyEditorFieldsToInstance(entity, script);
+			}
+
 			// Copy transforms... needs special handling for the Parent<->Child relations
 			for (let (sourceHandle, sourceTransform) in _ecsWorld.Enumerate<TransformComponent>())
 			{

GlitchyEngineHelper/src/Mono/Mono.bf

@@ -158,6 +158,9 @@ static class Mono
 	[LinkName(.C)]
 	public static extern MonoType* mono_reflection_type_get_type(MonoReflectionType* reflectionType);
 
+	[LinkName(.C)]
+	public static extern MonoReflectionType* mono_type_get_object(MonoDomain *domain, MonoType *type);
+
 	[LinkName(.C)]
 	public static extern MonoClassField* mono_class_get_fields(MonoClass* klass, gpointer* iter);
 	

ScriptCore/Editor/ShowInEditorAttribute.cs

@@ -2,6 +2,12 @@ using System;
 
 namespace GlitchyEngine.Editor;
 
+// TODO: Maybe rename, definitely move into different namespace
+/* Why?
+ * - this attribute also means that the Field is being serialized
+ * - Editor-Namespace wont be available for distribution builds of the game
+ */
+[AttributeUsage(AttributeTargets.Field)]
 public sealed class ShowInEditorAttribute : Attribute
 {
     public string DisplayName { get; set; } = null;