UI Tweaks, ChildEnumerator, ComponentAdded-Handlers

GlitchyEngine/src/Settings.bf

@@ -107,7 +107,7 @@ namespace GlitchyEngine
 	class ImGuiSettings
 	{
 		[Setting("UI", "Font Size"), BonInclude]
-		public int32 FontSize = 16;
+		public int32 FontSize = 14;
 
 		[Setting("UI", "Font name"), BonInclude]
 		public readonly String FontName = new .("Fonts/CascadiaCode.ttf") ~ delete _;

GlitchyEngine/src/World/Entity.bf

@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 
 using internal GlitchyEngine.World;
 
@@ -24,13 +25,53 @@ namespace GlitchyEngine.World
 			_scene = scene;
 		}
 
+		public ChildEnumerator EnumerateChildren => .(this);
+
 		public bool IsValid => _entity.IsValid;
 
+		public Entity? Parent
+		{
+			get
+			{
+				var cmp = GetComponent<TransformComponent>();
+
+				if (cmp.Parent == .InvalidEntity)
+					return null;
+
+				return .(cmp.Parent, _scene);
+			}
+			set
+			{
+				if (value == null)
+				{
+					var cmp = GetComponent<TransformComponent>();
+					cmp.Parent = .InvalidEntity;
+				}
+				else
+				{
+					Entity parent = value.Value;
+
+					if (parent.Scene != _scene)
+					{
+						Log.EngineLogger.AssertDebug(false);
+						return;
+					}
+
+					var cmp = GetComponent<TransformComponent>();
+					cmp.Parent = parent._entity;
+				}
+			}
+		}
+
 		public T* AddComponent<T>(T value = T()) where T: struct, new
 		{
 			Log.EngineLogger.AssertDebug(!HasComponent<T>(), scope $"Entity already has component.");
 
-			return _scene._ecsWorld.AssignComponent<T>(_entity, value);
+			T* component = _scene._ecsWorld.AssignComponent<T>(_entity, value);
+
+			_scene.[Friend]OnComponentAdded(this, typeof(T), component);
+
+			return component;
 		}
 
 		public T* GetComponent<T>() where T: struct, new
@@ -51,5 +92,41 @@ namespace GlitchyEngine.World
 
 			_scene._ecsWorld.RemoveComponent<T>(_entity);
 		}
+
+		public struct ChildEnumerator : IEnumerator<Entity>, IDisposable
+		{
+			private WorldEnumerator<TransformComponent> _transformEnum;
+
+			private EcsEntity _entity;
+			private Entity _currentChild;
+
+			public this(Entity entity)
+			{
+				_entity = entity.Handle;
+				_transformEnum = entity.Scene._ecsWorld.Enumerate<TransformComponent>();
+				_currentChild = .(.InvalidEntity, entity.Scene);
+			}
+
+			public Entity Current => _currentChild;
+
+			public Result<Entity> GetNext() mut
+			{
+				while (true)
+				{
+					(EcsEntity entity, TransformComponent* transform) = Try!(_transformEnum.GetNext());
+
+					if (transform.Parent == _entity)
+					{
+						_currentChild.[Friend]_entity = entity;
+						return .Ok(_currentChild);
+					}
+				}
+			}
+
+			public void Dispose()
+			{
+				_transformEnum.Dispose();
+			}
+		}
 	}
 }

GlitchyEngine/src/World/Scene.bf

@@ -1,6 +1,7 @@
 using GlitchyEngine.Math;
 using GlitchyEngine.Renderer;
 using System;
+using System.Collections;
 
 namespace GlitchyEngine.World
 {
@@ -9,6 +10,8 @@ namespace GlitchyEngine.World
 	class Scene
 	{
 		internal EcsWorld _ecsWorld = new .() ~ delete _;
+		
+		private Dictionary<Type, function void(Entity entity, Type componentType, void* component)> _onComponentAddedHandlers = new .() ~ delete _;
 
 		public this()
 		{
@@ -20,6 +23,11 @@ namespace GlitchyEngine.World
 			v.Sprite = new Texture2D("Textures/rocket.png");
 			v.Sprite.SamplerState = SamplerStateManager.PointClamp;
 
+			_onComponentAddedHandlers.Add(typeof(CameraComponent), (e, t, c) => {
+				CameraComponent* cameraComponent = (.)c;
+
+				cameraComponent.Camera.SetViewportSize(e.Scene.ViewportWidth, e.Scene.ViewportHeight);
+			});
 		}
 
 		public ~this()
@@ -68,6 +76,7 @@ namespace GlitchyEngine.World
 			}
 		}
 
+		/// Creates a new Entity with the given name.
 		public Entity CreateEntity(String name = "")
 		{
 			Entity entity = Entity(_ecsWorld.NewEntity(), this);
@@ -79,8 +88,20 @@ namespace GlitchyEngine.World
 			return entity;
 		}
 
-		public void DestroyEntity(Entity entity)
+		/** Deletes the given entity.
+		 * @param entity The entity to delete.
+		 * @param destroyChildren If set to true all children of entity will be destroyed.
+		*/
+		public void DestroyEntity(Entity entity, bool destroyChildren = false)
 		{
+			if (destroyChildren)
+			{
+				for (Entity child in entity.EnumerateChildren)
+				{
+					DestroyEntity(child, true);
+				}
+			}
+			
 			_ecsWorld.RemoveEntity(entity.Handle);
 		}
 
@@ -100,5 +121,13 @@ namespace GlitchyEngine.World
 				}
 			}
 		}
+
+		private void OnComponentAdded(Entity entity, Type componentType, void* component)
+		{
+			if (_onComponentAddedHandlers.TryGetValue(componentType, let handler))
+			{
+				handler(entity, componentType, component);
+			}
+		}
 	}
 }