Add utility to make spline curve linear or smooth

Source/Editor/Undo/Actions/EditSplineAction.cs

@@ -0,0 +1,73 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+using System;
+using FlaxEditor.Modules;
+using FlaxEngine;
+
+namespace FlaxEditor.Actions
+{
+    /// <summary>
+    /// Change <see cref="Spline"/> keyframes undo action.
+    /// </summary>
+    /// <seealso cref="FlaxEditor.IUndoAction" />
+    /// <seealso cref="FlaxEditor.ISceneEditAction" />
+    [Serializable]
+    public class EditSplineAction : IUndoAction, ISceneEditAction
+    {
+        [Serialize]
+        private Guid _splineId;
+
+        [Serialize]
+        private BezierCurve<Transform>.Keyframe[] _before;
+
+        [Serialize]
+        private BezierCurve<Transform>.Keyframe[] _after;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="EditSplineAction"/> class.
+        /// </summary>
+        /// <param name="spline">The spline.</param>
+        /// <param name="before">The spline keyframes state before editing it.</param>
+        public EditSplineAction(Spline spline, BezierCurve<Transform>.Keyframe[] before)
+        {
+            _splineId = spline.ID;
+            _before = before;
+            _after = (BezierCurve<Transform>.Keyframe[])spline.SplineKeyframes.Clone();
+        }
+
+        /// <inheritdoc />
+        public string ActionString => "Edit spline keyframes";
+
+        /// <inheritdoc />
+        public void Do()
+        {
+            var spline = FlaxEngine.Object.Find<Spline>(ref _splineId);
+            if (spline == null)
+                return;
+            spline.SplineKeyframes = _after;
+        }
+
+        /// <inheritdoc />
+        public void Undo()
+        {
+            var spline = FlaxEngine.Object.Find<Spline>(ref _splineId);
+            if (spline == null)
+                return;
+            spline.SplineKeyframes = _before;
+        }
+
+        /// <inheritdoc />
+        public void Dispose()
+        {
+            _before = _after = null;
+        }
+
+        /// <inheritdoc />
+        public void MarkSceneEdited(SceneModule sceneModule)
+        {
+            var spline = FlaxEngine.Object.Find<Spline>(ref _splineId);
+            if (spline != null)
+                sceneModule.MarkSceneEdited(spline.Scene);
+        }
+    }
+}