feat: Transform Hierarchy System

Engine.Core/Abstract/ITransform.cs

@@ -1,11 +1,12 @@
 using System;
+using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core.Abstract;
 
 /// <summary>
 /// Represents the transformation properties of an object such as position, scale, and rotation.
 /// </summary>
-public interface ITransform
+public interface ITransform : IEnumerable<ITransform>
 {
     /// <summary>
     /// Event triggered when the <see cref="Position"/> of the <see cref="ITransform"/> changes.
@@ -23,17 +24,61 @@ public interface ITransform
     Action<ITransform>? OnRotationChanged { get; set; }
 
     /// <summary>
-    /// The position of the <see cref="ITransform"/> in 2D space.
+    /// Event triggered when the <see cref="Parent"/> of the <see cref="ITransform"/> changes. The second parameter is the old <see cref="ITransform"/>.
+    /// </summary>
+    Action<ITransform, ITransform?>? OnParentChanged { get; set; }
+
+    /// <summary>
+    /// Event triggered when a new <see cref="ITransform"/> is added to the <see cref="Children"/>.
+    /// </summary>
+    Action<ITransform, ITransform>? OnChildrenAdded { get; set; }
+
+    /// <summary>
+    /// Event triggered when an <see cref="ITransform"/> is removed from the <see cref="Children"/>.
+    /// </summary>
+    Action<ITransform, ITransform>? OnChildrenRemoved { get; set; }
+
+    /// <summary>
+    /// The world position of the <see cref="ITransform"/> in 2D space.
     /// </summary>
     Vector2D Position { get; set; }
 
     /// <summary>
-    /// The scale of the <see cref="ITransform"/>.
+    /// The world scale of the <see cref="ITransform"/>.
     /// </summary>
     Vector2D Scale { get; set; }
 
     /// <summary>
-    /// The rotation of the <see cref="ITransform"/> in degrees.
+    /// The world rotation of the <see cref="ITransform"/> in degrees.
     /// </summary>
     float Rotation { get; set; }
+
+    /// <summary>
+    /// The local position of the <see cref="ITransform"/> in 2D space.
+    /// </summary>
+    Vector2D LocalPosition { get; set; }
+
+    /// <summary>
+    /// The local scale of the <see cref="ITransform"/>.
+    /// </summary>
+    Vector2D LocalScale { get; set; }
+
+    /// <summary>
+    /// The local rotation of the <see cref="ITransform"/> in degrees.
+    /// </summary>
+    float LocalRotation { get; set; }
+
+    /// <summary>
+    /// The parent <see cref="ITransform"/> of the <see cref="ITransform"/>.
+    /// </summary>
+    ITransform? Parent { get; }
+
+    /// <summary>
+    /// The <see cref="ITransform"/>s that have this <see cref="ITransform"/> as their <see cref="Parent"/>.
+    /// </summary>
+    IReadOnlyList<ITransform> Children { get; }
+
+    void SetParent(ITransform? transform);
+    void AddChild(ITransform transform);
+    void RemoveChild(ITransform transform);
 }