From 57b42d8daace146bacd125ff9d06bdf34fdfd568 Mon Sep 17 00:00:00 2001
From: max <max+github@vertexcolor.xyz>
Date: Tue, 22 Oct 2024 23:54:36 +0200
Subject: [PATCH] Really basic component inspection

---
 Nerfed.Editor/Program.cs                      |  5 +-
 .../Systems/EditorHierarchyWindow.cs          |  1 +
 .../Systems/EditorInspectorWindow.cs          | 56 +++++++++++++++++++
 Nerfed.Runtime/Components/LocalTransform.cs   | 15 ++---
 4 files changed, 65 insertions(+), 12 deletions(-)
 create mode 100644 Nerfed.Editor/Systems/EditorInspectorWindow.cs

diff --git a/Nerfed.Editor/Program.cs b/Nerfed.Editor/Program.cs
index accbefc..dcf929b 100644
--- a/Nerfed.Editor/Program.cs
+++ b/Nerfed.Editor/Program.cs
@@ -30,6 +30,9 @@ private static void HandleOnInitialize()
         systems.Add(new LocalToWorldSystem(world));
         editorSystems.Add(new EditorProfilerWindow(world));
         editorSystems.Add(new EditorHierarchyWindow(world));
+#if DEBUG
+        editorSystems.Add(new EditorInspectorWindow(world));
+#endif
 
         Entity ent1 = world.CreateEntity("parent");
         world.Set(ent1, new Root());
@@ -56,7 +59,7 @@ private static void HandleOnInitialize()
             Entity parent = newEnt;
             for (int j = 0; j < 2; j++) {
                 Entity newChildEnt = world.CreateEntity();
-                world.Set(newChildEnt, new LocalTransform(new Vector3(j, j, j), Quaternion.Identity, Vector3.One));
+                world.Set(newChildEnt, new LocalTransform(new Vector3(i + j * i, i - j * i, j - i * i), Quaternion.Identity, Vector3.One));
                 Transform.SetParent(world, newChildEnt, parent);
                 parent = newChildEnt;
             }
diff --git a/Nerfed.Editor/Systems/EditorHierarchyWindow.cs b/Nerfed.Editor/Systems/EditorHierarchyWindow.cs
index 4cbda6d..b19b8c5 100644
--- a/Nerfed.Editor/Systems/EditorHierarchyWindow.cs
+++ b/Nerfed.Editor/Systems/EditorHierarchyWindow.cs
@@ -96,6 +96,7 @@ private void DrawEntityAndChildren(in Entity entity)
 
             if (ImGui.TreeNodeEx($"{entity.ID} | {GetTag(entity)}", flags))
             {
+                // TODO: fix selection, look at ImGui 1.91, https://github.com/ocornut/imgui/wiki/Multi-Select
                 // Selection.
                 if (ImGui.IsItemClicked() && !ImGui.IsItemToggledOpen())
                 {
diff --git a/Nerfed.Editor/Systems/EditorInspectorWindow.cs b/Nerfed.Editor/Systems/EditorInspectorWindow.cs
new file mode 100644
index 0000000..de899a6
--- /dev/null
+++ b/Nerfed.Editor/Systems/EditorInspectorWindow.cs
@@ -0,0 +1,56 @@
+using ImGuiNET;
+using MoonTools.ECS;
+using Nerfed.Editor.Components;
+
+#if DEBUG
+namespace Nerfed.Editor.Systems
+{
+    // Window that draws entities.
+    internal class EditorInspectorWindow : MoonTools.ECS.DebugSystem
+    {
+        private readonly Filter selectedEntityFilter;
+
+        public EditorInspectorWindow(World world) : base(world)
+        {
+            selectedEntityFilter = FilterBuilder.Include<SelectedInHierachy>().Build();
+        }
+
+        public override void Update(TimeSpan delta)
+        {
+            ImGui.Begin("Inspector");
+
+            foreach (Entity entity in selectedEntityFilter.Entities)
+            {
+                DrawEntityComponents(entity);
+            }
+
+            ImGui.End();
+        }
+
+        private void DrawEntityComponents(Entity entity)
+        {
+            World.ComponentTypeEnumerator components = World.Debug_GetAllComponentTypes(entity);
+
+            foreach (Type type in components)
+            {
+                ImGui.Text(type.Name);
+            }
+
+            ImGui.Separator();
+
+            // TODO: explore something without reflection.
+            // Maybe generate some look up dictionary<type, Action<world, entity>> for 'custom editors'.
+            // Look into serializing of entities and components.
+            foreach (Type component in components)
+            {
+                System.Reflection.MethodInfo getMethodInfo = typeof(World).GetMethod("Get");
+                System.Reflection.MethodInfo getComponentMethod = getMethodInfo.MakeGenericMethod(component);
+                object result = getComponentMethod.Invoke(World, [entity]);
+
+                // process here
+                ImGui.Text(result.ToString());
+            }
+        }
+    }
+}
+#endif
\ No newline at end of file
diff --git a/Nerfed.Runtime/Components/LocalTransform.cs b/Nerfed.Runtime/Components/LocalTransform.cs
index 29207c0..bb0b810 100644
--- a/Nerfed.Runtime/Components/LocalTransform.cs
+++ b/Nerfed.Runtime/Components/LocalTransform.cs
@@ -2,18 +2,11 @@
 
 namespace Nerfed.Runtime.Components
 {
-    public struct LocalTransform
+    public readonly record struct LocalTransform(Vector3 position, Quaternion rotation, Vector3 scale)
     {
-        public Vector3 position;
-        public Quaternion rotation;
-        public Vector3 scale;
-
-        public LocalTransform(Vector3 position, Quaternion rotation, Vector3 scale)
-        {
-            this.position = position;
-            this.rotation = rotation;
-            this.scale = scale;
-        }
+        public readonly Vector3 position = position;
+        public readonly Quaternion rotation = rotation;
+        public readonly Vector3 scale = scale;
 
         public static readonly LocalTransform Identity = new(Vector3.Zero, Quaternion.Identity, Vector3.One);
     }