Replace external ImGui entt entity editor with in-engine editor panels

.gitmodules

@@ -37,6 +37,3 @@
 	path = external/SPIRV-Cross
 	url = https://github.com/flingengine/SPIRV-Cross.git
 
-[submodule "external/imgui_entt_entity_editor"]
-	path = external/imgui_entt_entity_editor
-	url = https://github.com/flingengine/imgui_entt_entity_editor.git

CMakeLists.txt

@@ -134,7 +134,6 @@ if( WITH_IMGUI_FLAG )
     target_include_directories( ImGui PUBLIC external/imgui )
 
     include_directories( external/imgui )
-    include_directories( external/imgui_entt_entity_editor )
 endif()
 
 include_directories( external/glm )

FlingEngine/Editor/inc/BaseEditor.h

@@ -2,7 +2,8 @@
 
 #include <imgui.h>
 #include <entt/entity/registry.hpp>
-#include "imgui_entt_entity_editor.hpp"
+#include "WorldOutlinePanel.h"
+#include "EntityEditorPanel.h"
 
 namespace Fling
 {
@@ -25,9 +26,9 @@ namespace Fling
          */
         virtual void Draw(entt::registry& t_Reg, float DeltaTime);
 
-        // #TODO: Init and shutdown functions 
+        // #TODO: Init and shutdown functions
 
-    protected: 
+    protected:
 
         virtual void OnLoadLevel(std::string t_FileName);
 
@@ -43,9 +44,11 @@ namespace Fling
 		bool m_DisplayWindowOptions = false;
         bool m_DisplayCameraOptions = false;
 
-		/** Component editor so that we can draw our component window */
-		entt::entity m_CompEditorEntityType = entt::null;
-		MM::ImGuiEntityEditor<entt::registry> m_ComponentEditor;
+		/** Lists entities in the world and tracks which one is selected */
+		WorldOutlinePanel m_WorldOutline;
+
+		/** Inspects the entity currently selected in m_WorldOutline */
+		EntityEditorPanel m_EntityEditor;
 
 		virtual void DrawFileMenu();
 
@@ -56,7 +59,7 @@ namespace Fling
         void DrawWorldOutline(entt::registry& t_Reg);
 
         /** assumes that m_DisplayComponentEditor is true */
-		void DrawComponentEditor(entt::registry& t_Reg);
+		void DrawEntityEditor(entt::registry& t_Reg);
 
 		void DrawWindowOptions();
 
@@ -70,4 +73,4 @@ namespace Fling
         // Draw Gizmos, etc
         // Draw component editor
     };
-}   // namespace Fling
+}   // namespace Fling

FlingEngine/Editor/inc/EntityEditorPanel.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "FlingEditorPanel.h"
+
+#include <entt/entity/registry.hpp>
+
+namespace Fling
+{
+	/**
+	 * Re-usable ImGui panel that inspects a single entity: lists the components
+	 * it has (via ComponentTypeRegistry), lets the user remove them, and offers
+	 * an "Add Component" popup for any registered type the entity doesn't have.
+	 */
+	class EntityEditorPanel final : public FlingEditorPanel
+	{
+	public:
+		/** Draws the "Entity Editor" window for the current target entity. Call once per frame. */
+		virtual void Draw(entt::registry& t_Reg) override;
+
+		/** Sets which entity this panel inspects. Pass entt::null to show none. */
+		void SetTargetEntity(entt::entity t_Entity) { m_TargetEntity = t_Entity; }
+
+	private:
+		entt::entity m_TargetEntity = entt::null;
+	};
+}	// namespace Fling

FlingEngine/Editor/inc/FlingEditorPanel.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <entt/entity/registry.hpp>
+
+namespace Fling
+{
+	/**
+	 * Base class for the engine's ImGui editor windows. 
+	 */
+	class FlingEditorPanel
+	{
+	public:
+		virtual ~FlingEditorPanel() = default;
+
+		/** Draws this panel's ImGui window. Call once per frame. */
+		virtual void Draw(entt::registry& t_Reg) = 0;
+
+		void Show() { m_ShowWindow = true; }
+		void Hide() { m_ShowWindow = false; }
+		bool IsShown() const { return m_ShowWindow; }
+
+	protected:
+		bool m_ShowWindow = true;
+	};
+}	// namespace Fling

FlingEngine/Editor/inc/WorldOutlinePanel.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "FlingEditorPanel.h"
+
+#include <entt/entity/registry.hpp>
+
+namespace Fling
+{
+	/**
+	 * Re-usable ImGui panel that lists every entity in a registry. Supports
+	 * creating and deleting entities, and tracks which entity is currently
+	 * selected so other editor windows (e.g. EntityEditorPanel) can follow it.
+	 */
+	class WorldOutlinePanel final : public FlingEditorPanel
+	{
+	public:
+		/** Draws the "World Outline" window. Call this once per frame. */
+		virtual void Draw(entt::registry& t_Reg) override;
+
+		entt::entity GetSelectedEntity() const { return m_SelectedEntity; }
+
+		void SetSelectedEntity(entt::entity t_Entity) { m_SelectedEntity = t_Entity; }
+
+	private:
+		entt::entity m_SelectedEntity = entt::null;
+	};
+}	// namespace Fling