refactor!: Transform events now send previous values of their changed fields

Engine.Core/Abstract/ITransform.cs

@@ -95,10 +95,46 @@ public interface ITransform : IAssignableGameObject, IEnumerable<ITransform>
     /// <param name="transform">The child <see cref="ITransform"/> to remove.</param>
     void RemoveChild(ITransform transform);
 
-    delegate void OnPositionChangedEventHandler(ITransform sender);
+    /// <summary>
-    delegate void OnScaleChangedEventHandler(ITransform sender);
+    /// Delegate for the event triggered when the <see cref="ITransform"/>'s rotation changes.
-    delegate void OnRotationChangedEventHandler(ITransform sender);
+    /// </summary>
+    /// <param name="sender">The <see cref="ITransform"/> that the parent has changed.</param>
+    /// <param name="previousPosition">The previous <see cref="Position"/> of the <see cref="ITransform"/>.</param>
+    delegate void OnPositionChangedEventHandler(ITransform sender, Vector2D previousPosition);
+
+    /// <summary>
+    /// Delegate for the event triggered when the <see cref="ITransform"/>'s rotation changes.
+    /// </summary>
+    /// <param name="sender">The <see cref="ITransform"/> that the parent has changed.</param>
+    /// <param name="previousScale">The previous <see cref="Scale"/> of the <see cref="ITransform"/>.</param>
+    delegate void OnScaleChangedEventHandler(ITransform sender, Vector2D previousScale);
+
+    /// <summary>
+    /// Delegate for the event triggered when the <see cref="ITransform"/>'s rotation changes.
+    /// </summary>
+    /// <param name="sender">The <see cref="ITransform"/> that the parent has changed.</param>
+    /// <param name="previousRotation">The previous <see cref="Rotation"/> of the <see cref="ITransform"/>.</param>
+    delegate void OnRotationChangedEventHandler(ITransform sender, float previousRotation);
+
+    /// <summary>
+    /// Delegate for the event triggered when the <see cref="ITransform"/>'s parent changes.
+    /// </summary>
+    /// <param name="sender">The <see cref="ITransform"/> that the parent has changed.</param>
+    /// <param name="previousParent">The previous <see cref="ITransform"/> the sender was a child of.</param>
+    /// <param name="newParent">The new and current <see cref="ITransform"/> the sender is a child of.</param>
     delegate void OnParentChangedEventHandler(ITransform sender, ITransform? previousParent, ITransform? newParent);
+
+    /// <summary>
+    /// Delegate for the event triggered when a new <see cref="ITransform"/> added as a child.
+    /// </summary>
+    /// <param name="sender">The parent <see cref="ITransform"/> this event is being called from.</param>
+    /// <param name="childrenAdded">The <see cref="ITransform"/> that got removed as a children of the sender <see cref="ITransform"/>.</param>
     delegate void OnChildrenAddedEventHandler(ITransform sender, ITransform childrenAdded);
+
+    /// <summary>
+    /// Delegate for the event triggered when a new <see cref="ITransform"/> removed from being a child.
+    /// </summary>
+    /// <param name="sender">The parent <see cref="ITransform"/> this event is being called from.</param>
+    /// <param name="childrenAdded">The <see cref="ITransform"/> that got removed as a children of the sender <see cref="ITransform"/>.</param>
     delegate void OnChildrenRemovedEventHandler(ITransform sender, ITransform childrenRemoved);
 }

Engine.Core/Transform.cs

@@ -43,9 +43,11 @@ public class Transform : ITransform
             if (value == _position)
                 return;
 
+            Vector2D previousPosition = _position;
             _position = value;
+
             UpdateLocalPosition();
-            OnPositionChanged?.Invoke(this);
+            OnPositionChanged?.Invoke(this, _position);
         }
     }
 
@@ -57,9 +59,11 @@ public class Transform : ITransform
             if (value == _scale)
                 return;
 
+            Vector2D previousScale = _scale;
             _scale = value;
+
             UpdateLocalScale();
-            OnScaleChanged?.Invoke(this);
+            OnScaleChanged?.Invoke(this, previousScale);
         }
     }
 
@@ -71,9 +75,12 @@ public class Transform : ITransform
             if (value == _rotation)
                 return;
 
+
+            float previousRotation = _rotation;
             _rotation = value;
+
             UpdateLocalPosition();
-            OnRotationChanged?.Invoke(this);
+            OnRotationChanged?.Invoke(this, previousRotation);
         }
     }
 
@@ -85,9 +92,11 @@ public class Transform : ITransform
             if (value == _localPosition)
                 return;
 
+            Vector2D previousPosition = _position;
             _localPosition = value;
+
             UpdatePosition();
-            OnPositionChanged?.Invoke(this);
+            OnPositionChanged?.Invoke(this, previousPosition);
         }
     }
 
@@ -99,9 +108,11 @@ public class Transform : ITransform
             if (value == _localScale)
                 return;
 
+            Vector2D previousScale = _scale;
             _localScale = value;
+
             UpdateScale();
-            OnScaleChanged?.Invoke(this);
+            OnScaleChanged?.Invoke(this, previousScale);
         }
     }
 
@@ -113,9 +124,11 @@ public class Transform : ITransform
             if (value == _localRotation)
                 return;
 
+            float previousRotation = _rotation;
             _localRotation = value;
+
             UpdateRotation();
-            OnRotationChanged?.Invoke(this);
+            OnRotationChanged?.Invoke(this, previousRotation);
         }
     }
 
@@ -182,33 +195,36 @@ public class Transform : ITransform
             child.SetParent(this);
     }
 
-    private void RecalculatePosition(ITransform _)
+    private void RecalculatePosition(ITransform _, Vector2D previousPosition)
     {
         if (Parent is null)
             return;
 
         UpdatePosition();
-        OnPositionChanged?.Invoke(this);
+
+        OnPositionChanged?.Invoke(this, previousPosition);
     }
 
-    private void RecalculateScale(ITransform _)
+    private void RecalculateScale(ITransform _, Vector2D previousScale)
     {
         if (Parent is null)
             return;
 
         UpdateScale();
-        OnScaleChanged?.Invoke(this);
+
+        OnScaleChanged?.Invoke(this, previousScale);
     }
 
-    private void RecalculateRotation(ITransform _)
+    private void RecalculateRotation(ITransform _, float previousRotation)
     {
         if (Parent is null)
             return;
 
-        UpdatePosition();
+        // UpdatePosition();
         UpdateRotation();
-        OnPositionChanged?.Invoke(this);
+
-        OnRotationChanged?.Invoke(this);
+        // OnPositionChanged?.Invoke(this, previousPosition);
+        OnRotationChanged?.Invoke(this, previousRotation);
     }
 
     private void UpdateLocalPosition()

Engine.Physics2D/Collider2DBehaviourBase.cs

@@ -39,9 +39,9 @@ public abstract class Collider2DBehaviourBase : Behaviour, ICollider2D
         BehaviourController.OnBehaviourAdded += OnBehaviourAddedToController;
         BehaviourController.OnBehaviourRemoved += OnBehaviourRemovedFromController;
 
-        Transform.OnPositionChanged += SetNeedsRecalculation;
+        Transform.OnPositionChanged += SetNeedsRecalculationFromPosition;
-        Transform.OnRotationChanged += SetNeedsRecalculation;
+        Transform.OnRotationChanged += SetNeedsRecalculationFromRotation;
-        Transform.OnScaleChanged += SetNeedsRecalculation;
+        Transform.OnScaleChanged += SetNeedsRecalculationFromScale;
         Transform.OnParentChanged += UpdateRigidBody2D;
     }
 
@@ -62,16 +62,18 @@ public abstract class Collider2DBehaviourBase : Behaviour, ICollider2D
             _rigidBody2D = null;
     }
 
-    private void SetNeedsRecalculation(ITransform transform) => NeedsRecalculation = true;
+    private void SetNeedsRecalculationFromScale(ITransform sender, Vector2D previousScale) => NeedsRecalculation = true;
+    private void SetNeedsRecalculationFromPosition(ITransform sender, Vector2D previousPosition) => NeedsRecalculation = true;
+    private void SetNeedsRecalculationFromRotation(ITransform sender, float previousRotation) => NeedsRecalculation = true;
 
     protected override void OnFinalize()
     {
         BehaviourController.OnBehaviourAdded -= OnBehaviourAddedToController;
         BehaviourController.OnBehaviourRemoved -= OnBehaviourRemovedFromController;
-        Transform.OnScaleChanged -= SetNeedsRecalculation;
+        Transform.OnScaleChanged -= SetNeedsRecalculationFromScale;
 
-        Transform.OnPositionChanged -= SetNeedsRecalculation;
+        Transform.OnPositionChanged -= SetNeedsRecalculationFromPosition;
-        Transform.OnRotationChanged -= SetNeedsRecalculation;
+        Transform.OnRotationChanged -= SetNeedsRecalculationFromRotation;
     }
 
     public void Detect(CollisionDetectionInformation collisionDetectionInformation) => OnCollisionDetected?.Invoke(this, collisionDetectionInformation);