Inital commit

22 files changed, 1299 insertions, 0 deletions

diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimationPreviewUtilities.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimationPreviewUtilities.cs
new file mode 100644
index 0000000..b8ab669
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimationPreviewUtilities.cs
@@ -0,0 +1,266 @@
+#if UNITY_EDITOR
+using System.Collections.Generic;
+using UnityEditor;
+
+
+namespace UnityEngine.Timeline
+{
+    static class AnimationPreviewUtilities
+    {
+        private const string k_PosX = "m_LocalPosition.x";
+        private const string k_PosY = "m_LocalPosition.y";
+        private const string k_PosZ = "m_LocalPosition.z";
+        private const string k_RotX = "m_LocalRotation.x";
+        private const string k_RotY = "m_LocalRotation.y";
+        private const string k_RotZ = "m_LocalRotation.z";
+        private const string k_RotW = "m_LocalRotation.w";
+        private const string k_ScaleX = "m_LocalScale.x";
+        private const string k_ScaleY = "m_LocalScale.y";
+        private const string k_ScaleZ = "m_LocalScale.z";
+        private const string k_EulerAnglesRaw = "localEulerAnglesRaw";
+        private const string k_EulerHint = "m_LocalEulerAnglesHint";
+        private const string k_Pos = "m_LocalPosition";
+        private const string k_Rot = "m_LocalRotation";
+        private const string k_MotionT = "MotionT";
+        private const string k_MotionQ = "MotionQ";
+        private const string k_RootT = "RootT";
+        private const string k_RootQ = "RootQ";
+
+
+        internal class EditorCurveBindingComparer : IEqualityComparer<EditorCurveBinding>
+        {
+            public bool Equals(EditorCurveBinding x, EditorCurveBinding y) { return x.path.Equals(y.path) && x.type == y.type && x.propertyName == y.propertyName; }
+            public int GetHashCode(EditorCurveBinding obj)
+            {
+                return obj.propertyName.GetHashCode() ^ obj.path.GetHashCode();
+            }
+
+            public static readonly EditorCurveBindingComparer Instance = new EditorCurveBindingComparer();
+        }
+
+        // a dictionary is faster than a hashset, because the capacity can be pre-set
+        private static readonly Dictionary<EditorCurveBinding, int> s_CurveSet = new Dictionary<EditorCurveBinding, int>(10000, EditorCurveBindingComparer.Instance);
+        private static readonly AnimatorBindingCache s_BindingCache = new AnimatorBindingCache();
+
+        public static void ClearCaches()
+        {
+            s_BindingCache.Clear();
+            s_CurveSet.Clear();
+        }
+
+        public static EditorCurveBinding[] GetBindings(GameObject animatorRoot, IEnumerable<AnimationClip> clips)
+        {
+            s_CurveSet.Clear();
+            foreach (var clip in clips)
+            {
+                AddBindings(s_BindingCache.GetCurveBindings(clip));
+            }
+
+            // if we have a transform binding, bind the entire skeleton
+            if (NeedsSkeletonBindings(s_CurveSet.Keys))
+                AddBindings(s_BindingCache.GetAnimatorBindings(animatorRoot));
+
+            var bindings = new EditorCurveBinding[s_CurveSet.Keys.Count];
+            s_CurveSet.Keys.CopyTo(bindings, 0);
+            return bindings;
+        }
+
+        public static void PreviewFromCurves(GameObject animatorRoot, IEnumerable<EditorCurveBinding> keys)
+        {
+            if (!AnimationMode.InAnimationMode())
+                return;
+
+            var avatarRoot = GetAvatarRoot(animatorRoot);
+            foreach (var binding in keys)
+            {
+                if (IsAvatarBinding(binding) || IsEuler(binding))
+                    continue;
+
+                bool isTransform = typeof(Transform).IsAssignableFrom(binding.type);
+                if (isTransform && binding.propertyName == AnimatorBindingCache.TRPlaceHolder)
+                    AddTRBinding(animatorRoot, binding);
+                else if (isTransform && binding.propertyName == AnimatorBindingCache.ScalePlaceholder)
+                    AddScaleBinding(animatorRoot, binding);
+                else
+                    AnimationMode.AddEditorCurveBinding(avatarRoot, binding);
+            }
+        }
+
+        public static AnimationClip CreateDefaultClip(GameObject animatorRoot, IEnumerable<EditorCurveBinding> keys)
+        {
+            AnimationClip animClip = new AnimationClip() { name = "DefaultPose" };
+            var keyFrames = new[] {new Keyframe(0, 0)};
+            var curve = new AnimationCurve(keyFrames);
+            bool rootMotion = false;
+            var avatarRoot = GetAvatarRoot(animatorRoot);
+
+            foreach (var binding in keys)
+            {
+                if (IsRootMotion(binding))
+                {
+                    rootMotion = true;
+                    continue;
+                }
+
+                if (typeof(Transform).IsAssignableFrom(binding.type) && binding.propertyName == AnimatorBindingCache.TRPlaceHolder)
+                {
+                    if (string.IsNullOrEmpty(binding.path))
+                        rootMotion = true;
+                    else
+                    {
+                        var transform = animatorRoot.transform.Find(binding.path);
+                        if (transform != null)
+                        {
+                            var pos = transform.localPosition;
+                            var rot = transform.localRotation;
+                            animClip.SetCurve(binding.path, typeof(Transform), k_PosX, SetZeroKey(curve, keyFrames, pos.x));
+                            animClip.SetCurve(binding.path, typeof(Transform), k_PosY, SetZeroKey(curve, keyFrames, pos.y));
+                            animClip.SetCurve(binding.path, typeof(Transform), k_PosZ, SetZeroKey(curve, keyFrames, pos.z));
+                            animClip.SetCurve(binding.path, typeof(Transform), k_RotX, SetZeroKey(curve, keyFrames, rot.x));
+                            animClip.SetCurve(binding.path, typeof(Transform), k_RotY, SetZeroKey(curve, keyFrames, rot.y));
+                            animClip.SetCurve(binding.path, typeof(Transform), k_RotZ, SetZeroKey(curve, keyFrames, rot.z));
+                            animClip.SetCurve(binding.path, typeof(Transform), k_RotW, SetZeroKey(curve, keyFrames, rot.w));
+                        }
+                    }
+
+                    continue;
+                }
+
+                if (typeof(Transform).IsAssignableFrom(binding.type) && binding.propertyName == AnimatorBindingCache.ScalePlaceholder)
+                {
+                    var transform = animatorRoot.transform.Find(binding.path);
+                    if (transform != null)
+                    {
+                        var scale = transform.localScale;
+                        animClip.SetCurve(binding.path, typeof(Transform), k_ScaleX, SetZeroKey(curve, keyFrames, scale.x));
+                        animClip.SetCurve(binding.path, typeof(Transform), k_ScaleY, SetZeroKey(curve, keyFrames, scale.y));
+                        animClip.SetCurve(binding.path, typeof(Transform), k_ScaleZ, SetZeroKey(curve, keyFrames, scale.z));
+                    }
+
+                    continue;
+                }
+
+                // Not setting curves through AnimationUtility.SetEditorCurve to avoid reentrant
+                // onCurveWasModified calls in timeline.  This means we don't get sprite curves
+                // in the default clip right now.
+                if (IsAvatarBinding(binding) || IsEulerHint(binding) || binding.isPPtrCurve)
+                    continue;
+
+                float floatValue;
+                AnimationUtility.GetFloatValue(avatarRoot, binding, out floatValue);
+                animClip.SetCurve(binding.path, binding.type, binding.propertyName, SetZeroKey(curve, keyFrames, floatValue));
+            }
+
+            // add root motion explicitly.
+            if (rootMotion)
+            {
+                var pos = Vector3.zero;           // the appropriate root motion offsets are applied by timeline
+                var rot = Quaternion.identity;
+                animClip.SetCurve(string.Empty, typeof(Transform), k_PosX, SetZeroKey(curve, keyFrames, pos.x));
+                animClip.SetCurve(string.Empty, typeof(Transform), k_PosY, SetZeroKey(curve, keyFrames, pos.y));
+                animClip.SetCurve(string.Empty, typeof(Transform), k_PosZ, SetZeroKey(curve, keyFrames, pos.z));
+                animClip.SetCurve(string.Empty, typeof(Transform), k_RotX, SetZeroKey(curve, keyFrames, rot.x));
+                animClip.SetCurve(string.Empty, typeof(Transform), k_RotY, SetZeroKey(curve, keyFrames, rot.y));
+                animClip.SetCurve(string.Empty, typeof(Transform), k_RotZ, SetZeroKey(curve, keyFrames, rot.z));
+                animClip.SetCurve(string.Empty, typeof(Transform), k_RotW, SetZeroKey(curve, keyFrames, rot.w));
+            }
+
+            return animClip;
+        }
+
+        public static bool IsRootMotion(EditorCurveBinding binding)
+        {
+            // Root Transform TR.
+            if (typeof(Transform).IsAssignableFrom(binding.type) && string.IsNullOrEmpty(binding.path))
+            {
+                return binding.propertyName.StartsWith(k_Pos) || binding.propertyName.StartsWith(k_Rot);
+            }
+
+            // MotionCurves/RootCurves.
+            if (binding.type == typeof(Animator))
+            {
+                return binding.propertyName.StartsWith(k_MotionT) || binding.propertyName.StartsWith(k_MotionQ) ||
+                    binding.propertyName.StartsWith(k_RootT) ||  binding.propertyName.StartsWith(k_RootQ);
+            }
+
+            return false;
+        }
+
+        private static bool NeedsSkeletonBindings(IEnumerable<EditorCurveBinding> bindings)
+        {
+            foreach (var b in bindings)
+            {
+                if (IsSkeletalBinding(b))
+                    return true;
+            }
+
+            return false;
+        }
+
+        private static void AddBindings(IEnumerable<EditorCurveBinding> bindings)
+        {
+            foreach (var b in bindings)
+            {
+                if (!s_CurveSet.ContainsKey(b))
+                    s_CurveSet[b] = 1;
+            }
+        }
+
+        private static void AddTRBinding(GameObject root, EditorCurveBinding binding)
+        {
+            // This is faster than AnimationMode.AddTransformTR
+            binding.propertyName = k_PosX; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_PosY; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_PosZ; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_RotX; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_RotY; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_RotZ; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_RotW; AnimationMode.AddEditorCurveBinding(root, binding);
+        }
+
+        private static void AddScaleBinding(GameObject root, EditorCurveBinding binding)
+        {
+            // AnimationMode.AddTransformTRS is slow
+            binding.propertyName = k_ScaleX; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_ScaleY; AnimationMode.AddEditorCurveBinding(root, binding);
+            binding.propertyName = k_ScaleZ; AnimationMode.AddEditorCurveBinding(root, binding);
+        }
+
+        private static bool IsEuler(EditorCurveBinding binding)
+        {
+            return typeof(Transform).IsAssignableFrom(binding.type) && binding.propertyName.StartsWith(k_EulerAnglesRaw);
+        }
+
+        private static bool IsAvatarBinding(EditorCurveBinding binding)
+        {
+            return typeof(Animator).IsAssignableFrom(binding.type) && string.IsNullOrEmpty(binding.path);
+        }
+
+        private static bool IsSkeletalBinding(EditorCurveBinding binding)
+        {
+            // skin mesh incorporates blend shapes
+            return typeof(Transform).IsAssignableFrom(binding.type) || typeof(SkinnedMeshRenderer).IsAssignableFrom(binding.type);
+        }
+
+        private static AnimationCurve SetZeroKey(AnimationCurve curve, Keyframe[] keys, float val)
+        {
+            keys[0].value = val;
+            curve.keys = keys;
+            return curve;
+        }
+
+        private static bool IsEulerHint(EditorCurveBinding binding)
+        {
+            return typeof(Transform).IsAssignableFrom(binding.type) && binding.propertyName.StartsWith(k_EulerHint);
+        }
+
+        private static GameObject GetAvatarRoot(GameObject animatorRoot)
+        {
+            var animator = animatorRoot.GetComponent<Animator>();
+            if (animator != null && animator.avatarRoot != animatorRoot.transform)
+                return animator.avatarRoot.gameObject;
+            return animatorRoot;
+        }
+    }
+}
+#endif
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimationPreviewUtilities.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimationPreviewUtilities.cs.meta
new file mode 100644
index 0000000..82e3768
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimationPreviewUtilities.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 01da6c5b7c781174d818662ce6f39b8b
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimatorBindingCache.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimatorBindingCache.cs
new file mode 100644
index 0000000..53198ea
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimatorBindingCache.cs
@@ -0,0 +1,133 @@
+#if UNITY_EDITOR
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.Playables;
+using UnityEngine.Timeline;
+using UnityEditor;
+
+namespace UnityEngine.Timeline
+{
+    /// <summary>
+    /// Animator to Editor Curve Binding cache. Used to prevent frequent calls to GetAnimatorBindings which can be costly
+    /// </summary>
+    class AnimatorBindingCache
+    {
+        public const string TRPlaceHolder = "TransformTR";
+        public const string ScalePlaceholder = "TransformScale";
+
+        struct AnimatorEntry
+        {
+            public int animatorID;
+            public bool applyRootMotion;
+            public bool humanoid;
+        }
+
+        class AnimatorEntryComparer : IEqualityComparer<AnimatorEntry>
+        {
+            public bool Equals(AnimatorEntry x, AnimatorEntry y) { return x.animatorID == y.animatorID && x.applyRootMotion == y.applyRootMotion && x.humanoid == y.humanoid; }
+            public int GetHashCode(AnimatorEntry obj) { return HashUtility.CombineHash(obj.animatorID, obj.applyRootMotion.GetHashCode(), obj.humanoid.GetHashCode()); }
+            public static readonly AnimatorEntryComparer Instance = new AnimatorEntryComparer();
+        }
+
+        readonly Dictionary<AnimatorEntry, EditorCurveBinding[]> m_AnimatorCache = new Dictionary<AnimatorEntry, EditorCurveBinding[]>(AnimatorEntryComparer.Instance);
+        readonly Dictionary<AnimationClip, EditorCurveBinding[]> m_ClipCache = new Dictionary<AnimationClip, EditorCurveBinding[]>();
+
+        private static readonly EditorCurveBinding[] kEmptyArray = new EditorCurveBinding[0];
+        private static readonly List<EditorCurveBinding> s_BindingScratchPad = new List<EditorCurveBinding>(1000);
+
+        public AnimatorBindingCache()
+        {
+            AnimationUtility.onCurveWasModified += OnCurveWasModified;
+        }
+
+        public EditorCurveBinding[] GetAnimatorBindings(GameObject gameObject)
+        {
+            if (gameObject == null)
+                return kEmptyArray;
+
+            Animator animator = gameObject.GetComponent<Animator>();
+            if (animator == null)
+                return kEmptyArray;
+
+            AnimatorEntry entry = new AnimatorEntry()
+            {
+                animatorID = animator.GetInstanceID(),
+                applyRootMotion = animator.applyRootMotion,
+                humanoid = animator.isHuman
+            };
+
+            EditorCurveBinding[] result = null;
+            if (m_AnimatorCache.TryGetValue(entry, out result))
+                return result;
+
+            s_BindingScratchPad.Clear();
+
+            // Replacement for AnimationMode.GetAnimatorBinding - this is faster and allocates kB instead of MB
+            var transforms = animator.GetComponentsInChildren<Transform>();
+            foreach (var t in transforms)
+            {
+                if (animator.IsBoneTransform(t))
+                    s_BindingScratchPad.Add(EditorCurveBinding.FloatCurve(AnimationUtility.CalculateTransformPath(t, animator.transform), typeof(Transform), TRPlaceHolder));
+            }
+
+            var streamBindings = AnimationUtility.GetAnimationStreamBindings(animator.gameObject);
+            UpdateTransformBindings(streamBindings);
+            s_BindingScratchPad.AddRange(streamBindings);
+
+            result = new EditorCurveBinding[s_BindingScratchPad.Count];
+            s_BindingScratchPad.CopyTo(result);
+            m_AnimatorCache[entry] = result;
+            return result;
+        }
+
+        public EditorCurveBinding[] GetCurveBindings(AnimationClip clip)
+        {
+            if (clip == null)
+                return kEmptyArray;
+
+            EditorCurveBinding[] result;
+            if (!m_ClipCache.TryGetValue(clip, out result))
+            {
+                result = AnimationMode.GetCurveBindings(clip);
+                UpdateTransformBindings(result);
+                m_ClipCache[clip] = result;
+            }
+
+            return result;
+        }
+
+        private static void UpdateTransformBindings(EditorCurveBinding[] bindings)
+        {
+            for (int i = 0; i < bindings.Length; i++)
+            {
+                var binding = bindings[i];
+                if (AnimationPreviewUtilities.IsRootMotion(binding))
+                {
+                    binding.type = typeof(Transform);
+                    binding.propertyName = TRPlaceHolder;
+                }
+                else if (typeof(Transform).IsAssignableFrom(binding.type) && (binding.propertyName.StartsWith("m_LocalRotation.") || binding.propertyName.StartsWith("m_LocalPosition.")))
+                {
+                    binding.propertyName = TRPlaceHolder;
+                }
+                else if (typeof(Transform).IsAssignableFrom(binding.type) && binding.propertyName.StartsWith("m_LocalScale."))
+                {
+                    binding.propertyName = ScalePlaceholder;
+                }
+                bindings[i] = binding;
+            }
+        }
+
+        public void Clear()
+        {
+            m_AnimatorCache.Clear();
+            m_ClipCache.Clear();
+        }
+
+        void OnCurveWasModified(AnimationClip clip, EditorCurveBinding binding, AnimationUtility.CurveModifiedType modification)
+        {
+            m_ClipCache.Remove(clip);
+        }
+    }
+}
+#endif
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimatorBindingCache.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimatorBindingCache.cs.meta
new file mode 100644
index 0000000..dc6dc1d
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/AnimatorBindingCache.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: d0080567f62c3f94cb75b2927a349e22
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
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diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/Extrapolation.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/Extrapolation.cs
new file mode 100644
index 0000000..34408c9
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/Extrapolation.cs
@@ -0,0 +1,92 @@
+using System;
+using UnityEngine;
+
+// Extension methods responsible for managing extrapolation time
+namespace UnityEngine.Timeline
+{
+    static class Extrapolation
+    {
+        /// <summary>
+        /// The minimum amount of extrapolation time to apply
+        /// </summary>
+        internal static readonly double kMinExtrapolationTime = TimeUtility.kTimeEpsilon * 1000;
+
+        // Calculates the extrapolation times
+        internal static void CalculateExtrapolationTimes(this TrackAsset asset)
+        {
+            TimelineClip[] clips = asset.clips;
+            if (clips == null || clips.Length == 0)
+                return;
+
+            // extrapolation not supported
+            if (!clips[0].SupportsExtrapolation())
+                return;
+
+            var orderedClips = SortClipsByStartTime(clips);
+            if (orderedClips.Length > 0)
+            {
+                // post extrapolation is the minimum time to the next clip
+                for (int i = 0; i < orderedClips.Length; i++)
+                {
+                    double minTime = double.PositiveInfinity;
+                    for (int j = 0; j < orderedClips.Length; j++)
+                    {
+                        if (i == j)
+                            continue;
+
+                        double deltaTime = orderedClips[j].start - orderedClips[i].end;
+                        if (deltaTime >= -TimeUtility.kTimeEpsilon && deltaTime < minTime)
+                            minTime = Math.Min(minTime, deltaTime);
+                        // check for overlapped clips
+                        if (orderedClips[j].start <= orderedClips[i].end && orderedClips[j].end > orderedClips[i].end)
+                            minTime = 0;
+                    }
+                    minTime = minTime <= kMinExtrapolationTime ? 0 : minTime;
+                    orderedClips[i].SetPostExtrapolationTime(minTime);
+                }
+
+                // the first clip gets pre-extrapolation, then it's only respected if there is no post extrapolation
+                orderedClips[0].SetPreExtrapolationTime(Math.Max(0, orderedClips[0].start));
+                for (int i = 1; i < orderedClips.Length; i++)
+                {
+                    double preTime = 0;
+                    int prevClip = -1;
+                    for (int j = 0; j < i; j++)
+                    {
+                        // overlap, no pre-time
+                        if (orderedClips[j].end > orderedClips[i].start)
+                        {
+                            prevClip = -1;
+                            preTime = 0;
+                            break;
+                        }
+
+                        double gap = orderedClips[i].start - orderedClips[j].end;
+                        if (prevClip == -1 || gap < preTime)
+                        {
+                            preTime = gap;
+                            prevClip = j;
+                        }
+                    }
+                    // check for a post extrapolation time
+                    if (prevClip >= 0)
+                    {
+                        if (orderedClips[prevClip].postExtrapolationMode != TimelineClip.ClipExtrapolation.None)
+                            preTime = 0;
+                    }
+
+                    preTime = preTime <= kMinExtrapolationTime ? 0 : preTime;
+                    orderedClips[i].SetPreExtrapolationTime(preTime);
+                }
+            }
+        }
+
+        static TimelineClip[] SortClipsByStartTime(TimelineClip[] clips)
+        {
+            var orderedClips = new TimelineClip[clips.Length];
+            Array.Copy(clips, orderedClips, clips.Length);
+            Array.Sort(orderedClips, (clip1, clip2) => clip1.start.CompareTo(clip2.start));
+            return orderedClips;
+        }
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/Extrapolation.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/Extrapolation.cs.meta
new file mode 100644
index 0000000..69c90cf
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/Extrapolation.cs.meta
@@ -0,0 +1,11 @@
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+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/HashUtility.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/HashUtility.cs
new file mode 100644
index 0000000..81fa940
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/HashUtility.cs
@@ -0,0 +1,51 @@
+namespace UnityEngine.Timeline
+{
+    static class HashUtility
+    {
+        // Note. We could have used "params int[] hashes" but we want to avoid allocating.
+
+        public static int CombineHash(this int h1, int h2)
+        {
+            return h1 ^ (int)(h2 + 0x9e3779b9 + (h1 << 6) + (h1 >> 2)); // Similar to c++ boost::hash_combine
+        }
+
+        public static int CombineHash(int h1, int h2, int h3)
+        {
+            return CombineHash(h1, h2).CombineHash(h3);
+        }
+
+        public static int CombineHash(int h1, int h2, int h3, int h4)
+        {
+            return CombineHash(h1, h2, h3).CombineHash(h4);
+        }
+
+        public static int CombineHash(int h1, int h2, int h3, int h4, int h5)
+        {
+            return CombineHash(h1, h2, h3, h4).CombineHash(h5);
+        }
+
+        public static int CombineHash(int h1, int h2, int h3, int h4, int h5, int h6)
+        {
+            return CombineHash(h1, h2, h3, h4, h5).CombineHash(h6);
+        }
+
+        public static int CombineHash(int h1, int h2, int h3, int h4, int h5, int h6, int h7)
+        {
+            return CombineHash(h1, h2, h3, h4, h5, h6).CombineHash(h7);
+        }
+
+        public static int CombineHash(int[] hashes)
+        {
+            if (hashes == null || hashes.Length == 0)
+                return 0;
+
+            var h = hashes[0];
+            for (int i = 1; i < hashes.Length; ++i)
+            {
+                h = CombineHash(h, hashes[i]);
+            }
+
+            return h;
+        }
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/HashUtility.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/HashUtility.cs.meta
new file mode 100644
index 0000000..fec5c19
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/HashUtility.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: d0ca7b2e84542bf4ab9987087e8d79ad
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyCollector.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyCollector.cs
new file mode 100644
index 0000000..08f991a
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyCollector.cs
@@ -0,0 +1,102 @@
+using System.Collections.Generic;
+
+namespace UnityEngine.Timeline
+{
+    /// <summary>
+    /// Interface used to inform the Timeline Editor about potential property modifications that may occur while previewing.
+    /// </summary>
+    public interface IPropertyCollector
+    {
+        /// <summary>
+        /// Sets the active game object for subsequent property modifications.
+        /// </summary>
+        /// <param name="gameObject">The GameObject to push.</param>
+        void PushActiveGameObject(GameObject gameObject);
+
+        /// <summary>
+        /// Removes the active GameObject from the modification stack, restoring the previous value.
+        /// </summary>
+        void PopActiveGameObject();
+
+        /// <summary>
+        /// Add properties modified by an animation clip.
+        /// </summary>
+        /// <param name="clip">The animation clip that contains the properties</param>
+        void AddFromClip(AnimationClip clip);
+
+        /// <summary>
+        /// Add property modifications specified by a list of animation clips.
+        /// </summary>
+        /// <param name="clips">The list of animation clips used to determine which property modifications to apply.</param>
+        void AddFromClips(IEnumerable<AnimationClip> clips);
+
+        /// <summary>
+        /// Add property modifications using the serialized property name.
+        /// </summary>
+        /// <param name="name">The name of the serialized property</param>
+        /// <typeparam name="T">The type of the component the property exists on</typeparam>
+        /// <remarks>
+        /// This method uses the most recent gameObject from PushActiveGameObject
+        /// </remarks>
+        void AddFromName<T>(string name) where T : Component;
+
+        /// <summary>
+        /// Add property modifications using the serialized property name.
+        /// </summary>
+        /// <param name="name">The name of the serialized property</param>
+        /// <remarks>
+        /// This method uses the most recent gameObject from PushActiveGameObject
+        /// </remarks>
+        void AddFromName(string name);
+
+        /// <summary>
+        /// Add property modifications modified by an animation clip.
+        /// </summary>
+        /// <param name="obj">The GameObject where the properties exist</param>
+        /// <param name="clip">The animation clip that contains the properties</param>
+        void AddFromClip(GameObject obj, AnimationClip clip);
+
+        /// <summary>
+        /// Add property modifications specified by a list of animation clips.
+        /// </summary>
+        /// <param name="obj">The gameObject that will be animated</param>
+        /// <param name="clips">The list of animation clips used to determine which property modifications to apply.</param>
+        void AddFromClips(GameObject obj, IEnumerable<AnimationClip> clips);
+
+        /// <summary>
+        /// Add property modifications using the serialized property name.
+        /// </summary>
+        /// <param name="name">The name of the serialized property</param>
+        /// <param name="obj">The gameObject where the properties exist</param>
+        /// <typeparam name="T">The type of the component the property exists on</typeparam>>
+        void AddFromName<T>(GameObject obj, string name) where T : Component;
+
+        /// <summary>
+        /// Add property modifications using the serialized property name.
+        /// </summary>
+        /// <param name="obj">The gameObject where the properties exist</param>
+        /// <param name="name">The name of the serialized property</param>
+        void AddFromName(GameObject obj, string name);
+
+        /// <summary>
+        /// Add property modifications using the serialized property name.
+        /// </summary>
+        /// <param name="name">The name of the serialized property</param>
+        /// <param name="component">The component where the properties exist</param>
+        void AddFromName(Component component, string name);
+
+        /// <summary>
+        /// Set all serializable properties on a component to be under preview control.
+        /// </summary>
+        /// <param name="obj">The gameObject where the properties exist</param>
+        /// <param name="component">The component to set in preview mode</param>
+        void AddFromComponent(GameObject obj, Component component);
+
+        /// <summary>
+        /// Add property modifications modified by an animation clip.
+        /// </summary>
+        /// <param name="obj">The Object where the properties exist</param>
+        /// <param name="clip">The animation clip that contains the properties</param>
+        void AddObjectProperties(Object obj, AnimationClip clip);
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyCollector.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyCollector.cs.meta
new file mode 100644
index 0000000..05ecf1d
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyCollector.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 66b2b8fd1d9b4bc4c96b07335ad822f3
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
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diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyPreview.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyPreview.cs
new file mode 100644
index 0000000..b779f15
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyPreview.cs
@@ -0,0 +1,17 @@
+using UnityEngine.Playables;
+
+namespace UnityEngine.Timeline
+{
+    /// <summary>
+    /// Implement this interface in a PlayableAsset to specify which properties will be modified when Timeline is in preview mode.
+    /// </summary>
+    public interface IPropertyPreview
+    {
+        /// <summary>
+        /// Called by the Timeline Editor to gather properties requiring preview.
+        /// </summary>
+        /// <param name="director">The PlayableDirector invoking the preview</param>
+        /// <param name="driver">PropertyCollector used to gather previewable properties</param>
+        void GatherProperties(PlayableDirector director, IPropertyCollector driver);
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyPreview.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyPreview.cs.meta
new file mode 100644
index 0000000..31806d8
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/IPropertyPreview.cs.meta
@@ -0,0 +1,11 @@
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+  defaultReferences: []
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diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/NotificationUtilities.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/NotificationUtilities.cs
new file mode 100644
index 0000000..41aabce
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/NotificationUtilities.cs
@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine.Playables;
+
+namespace UnityEngine.Timeline
+{
+    static class NotificationUtilities
+    {
+        public static ScriptPlayable<TimeNotificationBehaviour> CreateNotificationsPlayable(PlayableGraph graph, IEnumerable<IMarker> markers, GameObject go)
+        {
+            var notificationPlayable = ScriptPlayable<TimeNotificationBehaviour>.Null;
+            var director = go.GetComponent<PlayableDirector>();
+            foreach (var e in markers)
+            {
+                var notif = e as INotification;
+                if (notif == null)
+                    continue;
+
+                if (notificationPlayable.Equals(ScriptPlayable<TimeNotificationBehaviour>.Null))
+                {
+                    notificationPlayable = TimeNotificationBehaviour.Create(graph,
+                        director.playableAsset.duration, director.extrapolationMode);
+                }
+
+                var time = (DiscreteTime)e.time;
+                var tlDuration = (DiscreteTime)director.playableAsset.duration;
+                if (time >= tlDuration && time <= tlDuration.OneTickAfter() && tlDuration != 0)
+                {
+                    time = tlDuration.OneTickBefore();
+                }
+
+                var notificationOptionProvider = e as INotificationOptionProvider;
+                if (notificationOptionProvider != null)
+                {
+                    notificationPlayable.GetBehaviour().AddNotification((double)time, notif, notificationOptionProvider.flags);
+                }
+                else
+                {
+                    notificationPlayable.GetBehaviour().AddNotification((double)time, notif);
+                }
+            }
+
+            return notificationPlayable;
+        }
+
+        public static bool TrackTypeSupportsNotifications(Type type)
+        {
+            var binding = (TrackBindingTypeAttribute)Attribute.GetCustomAttribute(type, typeof(TrackBindingTypeAttribute));
+            return binding != null &&
+                (typeof(Component).IsAssignableFrom(binding.type) ||
+                    typeof(GameObject).IsAssignableFrom(binding.type));
+        }
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/NotificationUtilities.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/NotificationUtilities.cs.meta
new file mode 100644
index 0000000..6e5c8c3
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+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/NotificationUtilities.cs.meta
@@ -0,0 +1,11 @@
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diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimeUtility.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimeUtility.cs
new file mode 100644
index 0000000..549de4c
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimeUtility.cs
@@ -0,0 +1,212 @@
+using System;
+using System.Text.RegularExpressions;
+
+namespace UnityEngine.Timeline
+{
+    // Sequence specific utilities for time manipulation
+    static class TimeUtility
+    {
+        // chosen because it will cause no rounding errors between time/frames for frames values up to at least 10 million
+        public static readonly double kTimeEpsilon = 1e-14;
+        public static readonly double kFrameRateEpsilon = 1e-6;
+        public static readonly double k_MaxTimelineDurationInSeconds = 9e6; //104 days of running time
+
+        static void ValidateFrameRate(double frameRate)
+        {
+            if (frameRate <= kTimeEpsilon)
+                throw new ArgumentException("frame rate cannot be 0 or negative");
+        }
+
+        public static int ToFrames(double time, double frameRate)
+        {
+            ValidateFrameRate(frameRate);
+            time = Math.Min(Math.Max(time, -k_MaxTimelineDurationInSeconds), k_MaxTimelineDurationInSeconds);
+            // this matches OnFrameBoundary
+            double tolerance = GetEpsilon(time, frameRate) / 2.0;
+            if (time < 0)
+            {
+                return (int)Math.Ceiling(time * frameRate - tolerance);
+            }
+            return (int)Math.Floor(time * frameRate + tolerance);
+        }
+
+        public static double ToExactFrames(double time, double frameRate)
+        {
+            ValidateFrameRate(frameRate);
+            return time * frameRate;
+        }
+
+        public static double FromFrames(int frames, double frameRate)
+        {
+            ValidateFrameRate(frameRate);
+            return (frames / frameRate);
+        }
+
+        public static double FromFrames(double frames, double frameRate)
+        {
+            ValidateFrameRate(frameRate);
+            return frames / frameRate;
+        }
+
+        public static bool OnFrameBoundary(double time, double frameRate)
+        {
+            return OnFrameBoundary(time, frameRate, GetEpsilon(time, frameRate));
+        }
+
+        public static double GetEpsilon(double time, double frameRate)
+        {
+            return Math.Max(Math.Abs(time), 1) * frameRate * kTimeEpsilon;
+        }
+
+        public static bool OnFrameBoundary(double time, double frameRate, double epsilon)
+        {
+            ValidateFrameRate(frameRate);
+
+            double exact = ToExactFrames(time, frameRate);
+            double rounded = Math.Round(exact);
+
+            return Math.Abs(exact - rounded) < epsilon;
+        }
+
+        public static double RoundToFrame(double time, double frameRate)
+        {
+            ValidateFrameRate(frameRate);
+
+            var frameBefore = (int)Math.Floor(time * frameRate) / frameRate;
+            var frameAfter = (int)Math.Ceiling(time * frameRate) / frameRate;
+
+            return Math.Abs(time - frameBefore) < Math.Abs(time - frameAfter) ? frameBefore : frameAfter;
+        }
+
+        public static string TimeAsFrames(double timeValue, double frameRate, string format = "F2")
+        {
+            if (OnFrameBoundary(timeValue, frameRate)) // make integral values when on time borders
+                return ToFrames(timeValue, frameRate).ToString();
+            return ToExactFrames(timeValue, frameRate).ToString(format);
+        }
+
+        public static string TimeAsTimeCode(double timeValue, double frameRate, string format = "F2")
+        {
+            ValidateFrameRate(frameRate);
+
+            int intTime = (int)Math.Abs(timeValue);
+
+            int hours = intTime / 3600;
+            int minutes = (intTime % 3600) / 60;
+            int seconds = intTime % 60;
+
+            string result;
+            string sign = timeValue < 0 ? "-" : string.Empty;
+            if (hours > 0)
+                result = hours + ":" + minutes.ToString("D2") + ":" + seconds.ToString("D2");
+            else if (minutes > 0)
+                result = minutes + ":" + seconds.ToString("D2");
+            else
+                result = seconds.ToString();
+
+            int frameDigits = (int)Math.Floor(Math.Log10(frameRate) + 1);
+
+            // Add partial digits on the frame if needed.
+            // we are testing the original value (not the truncated), because the truncation can cause rounding errors leading
+            // to invalid strings for items on frame boundaries
+            string frames = (ToFrames(timeValue, frameRate) - ToFrames(intTime, frameRate)).ToString().PadLeft(frameDigits, '0');
+            if (!OnFrameBoundary(timeValue, frameRate))
+            {
+                string decimals = ToExactFrames(timeValue, frameRate).ToString(format);
+                int decPlace = decimals.IndexOf('.');
+                if (decPlace >= 0)
+                    frames += " [" + decimals.Substring(decPlace) + "]";
+            }
+
+            return sign + result + ":" + frames;
+        }
+
+        // Given a time code string, return the time in seconds
+        // 1.5 -> 1.5 seconds
+        // 1:1.5 -> 1 minute, 1.5 seconds
+        // 1:1[.5] -> 1 second, 1.5 frames
+        // 2:3:4 -> 2 minutes, 3 seconds, 4 frames
+        // 1[.6] -> 1.6 frames
+        public static double ParseTimeCode(string timeCode, double frameRate, double defaultValue)
+        {
+            timeCode = RemoveChar(timeCode, c => char.IsWhiteSpace(c));
+            string[] sections = timeCode.Split(':');
+            if (sections.Length == 0 || sections.Length > 4)
+                return defaultValue;
+
+            int hours = 0;
+            int minutes = 0;
+            double seconds = 0;
+            double frames = 0;
+
+            try
+            {
+                // depending on the format of the last numbers
+                // seconds format
+                string lastSection = sections[sections.Length - 1];
+                if (Regex.Match(lastSection, @"^\d+\.\d+$").Success)
+                {
+                    seconds = double.Parse(lastSection);
+                    if (sections.Length > 3) return defaultValue;
+                    if (sections.Length > 1) minutes = int.Parse(sections[sections.Length - 2]);
+                    if (sections.Length > 2) hours = int.Parse(sections[sections.Length - 3]);
+                }
+                // frame formats
+                else
+                {
+                    if (Regex.Match(lastSection, @"^\d+\[\.\d+\]$").Success)
+                    {
+                        string stripped = RemoveChar(lastSection, c => c == '[' || c == ']');
+                        frames = double.Parse(stripped);
+                    }
+                    else if (Regex.Match(lastSection, @"^\d*$").Success)
+                    {
+                        frames = int.Parse(lastSection);
+                    }
+                    else
+                    {
+                        return defaultValue;
+                    }
+
+                    if (sections.Length > 1) seconds = int.Parse(sections[sections.Length - 2]);
+                    if (sections.Length > 2) minutes = int.Parse(sections[sections.Length - 3]);
+                    if (sections.Length > 3) hours = int.Parse(sections[sections.Length - 4]);
+                }
+            }
+            catch (FormatException)
+            {
+                return defaultValue;
+            }
+
+            return frames / frameRate + seconds + minutes * 60 + hours * 3600;
+        }
+
+        // fixes rounding errors from using single precision for length
+        public static double GetAnimationClipLength(AnimationClip clip)
+        {
+            if (clip == null || clip.empty)
+                return 0;
+
+            double length = clip.length;
+            if (clip.frameRate > 0)
+            {
+                double frames = Mathf.Round(clip.length * clip.frameRate);
+                length = frames / clip.frameRate;
+            }
+            return length;
+        }
+
+        static string RemoveChar(string str, Func<char, bool> charToRemoveFunc)
+        {
+            var len = str.Length;
+            var src = str.ToCharArray();
+            var dstIdx = 0;
+            for (var i = 0; i < len; i++)
+            {
+                if (!charToRemoveFunc(src[i]))
+                    src[dstIdx++] = src[i];
+            }
+            return new string(src, 0, dstIdx);
+        }
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimeUtility.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimeUtility.cs.meta
new file mode 100644
index 0000000..ff1d820
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+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimeUtility.cs.meta
@@ -0,0 +1,11 @@
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diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineCreateUtilities.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineCreateUtilities.cs
new file mode 100644
index 0000000..0870e40
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineCreateUtilities.cs
@@ -0,0 +1,131 @@
+using System;
+using System.Collections.Generic;
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
+
+namespace UnityEngine.Timeline
+{
+    static class TimelineCreateUtilities
+    {
+        // based off of ObjectNames.GetUniqueName, but can exist in runtime
+        public static string GenerateUniqueActorName(List<ScriptableObject> tracks, string name)
+        {
+            if (!tracks.Exists(x => ((object)x) != null && x.name == name))
+                return name;
+
+            int numberInParentheses = 0;
+            string baseName = name;
+
+            if (!string.IsNullOrEmpty(name) && name[name.Length - 1] == ')')
+            {
+                int index = name.LastIndexOf('(');
+                if (index > 0)
+                {
+                    string numberString = name.Substring(index + 1, name.Length - index - 2);
+                    if (int.TryParse(numberString, out numberInParentheses))
+                    {
+                        numberInParentheses++;
+                        baseName = name.Substring(0, index);
+                    }
+                }
+            }
+
+            baseName = baseName.TrimEnd();
+
+            for (int i = numberInParentheses; i < numberInParentheses + 5000; i++)
+            {
+                if (i > 0)
+                {
+                    string result = string.Format("{0} ({1})", baseName, i);
+                    if (!tracks.Exists(x => ((object)x) != null && x.name == result))
+                        return result;
+                }
+            }
+
+            // Fallback
+            return name;
+        }
+
+        public static void SaveAssetIntoObject(Object childAsset, Object masterAsset)
+        {
+            if (childAsset == null || masterAsset == null)
+                return;
+
+            if ((masterAsset.hideFlags & HideFlags.DontSave) != 0)
+            {
+                childAsset.hideFlags |= HideFlags.DontSave;
+            }
+            else
+            {
+                childAsset.hideFlags |= HideFlags.HideInHierarchy;
+#if UNITY_EDITOR
+                if (!AssetDatabase.Contains(childAsset) && AssetDatabase.Contains(masterAsset))
+                    AssetDatabase.AddObjectToAsset(childAsset, masterAsset);
+#endif
+            }
+        }
+
+        public static AnimationClip CreateAnimationClipForTrack(string name, TrackAsset track, bool isLegacy)
+        {
+            var timelineAsset = track != null ? track.timelineAsset : null;
+            var trackFlags = track != null ? track.hideFlags : HideFlags.None;
+
+            var curves = new AnimationClip
+            {
+                legacy = isLegacy,
+
+                name = name,
+
+                frameRate = timelineAsset == null
+                    ? TimelineAsset.EditorSettings.kDefaultFps
+                    : timelineAsset.editorSettings.fps
+            };
+
+            SaveAssetIntoObject(curves, timelineAsset);
+            curves.hideFlags = trackFlags & ~HideFlags.HideInHierarchy; // Never hide in hierarchy
+
+            TimelineUndo.RegisterCreatedObjectUndo(curves, "Create Curves");
+
+            return curves;
+        }
+
+        public static bool ValidateParentTrack(TrackAsset parent, Type childType)
+        {
+            if (childType == null || !typeof(TrackAsset).IsAssignableFrom(childType))
+                return false;
+
+            // no parent is valid for any type
+            if (parent == null)
+                return true;
+
+            // A track supports layers if it implements ILayerable. Only supported for parents that are
+            // the same exact type as the child class, and 1 level of nesting only
+            if (parent is ILayerable && !parent.isSubTrack && parent.GetType() == childType)
+                return true;
+
+            var attr = Attribute.GetCustomAttribute(parent.GetType(), typeof(SupportsChildTracksAttribute)) as SupportsChildTracksAttribute;
+            if (attr == null)
+                return false;
+
+            // group track case, accepts all
+            if (attr.childType == null)
+                return true;
+
+            // specific case. Specifies nesting level
+            if (childType == attr.childType)
+            {
+                int nestCount = 0;
+                var p = parent;
+                while (p != null && p.isSubTrack)
+                {
+                    nestCount++;
+                    p = p.parent as TrackAsset;
+                }
+
+                return nestCount < attr.levels;
+            }
+            return false;
+        }
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineCreateUtilities.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineCreateUtilities.cs.meta
new file mode 100644
index 0000000..f81aa91
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diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs
new file mode 100644
index 0000000..b6392f0
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs
@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using UnityEngine.Playables;
+
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
+
+namespace UnityEngine.Timeline
+{
+    static class TimelineUndo
+    {
+        public static void PushDestroyUndo(TimelineAsset timeline, Object thingToDirty, Object objectToDestroy, string operation)
+        {
+#if UNITY_EDITOR
+            if (objectToDestroy == null || !DisableUndoGuard.enableUndo)
+                return;
+
+            if (thingToDirty != null)
+                EditorUtility.SetDirty(thingToDirty);
+
+            if (timeline != null)
+                EditorUtility.SetDirty(timeline);
+
+            Undo.DestroyObjectImmediate(objectToDestroy);
+#else
+            if (objectToDestroy != null)
+                Object.Destroy(objectToDestroy);
+#endif
+        }
+
+        [Conditional("UNITY_EDITOR")]
+        public static void PushUndo(Object thingToDirty, string operation)
+        {
+#if UNITY_EDITOR
+            if (thingToDirty != null && DisableUndoGuard.enableUndo)
+            {
+                var track = thingToDirty as TrackAsset;
+                if (track != null)
+                    track.MarkDirty();
+
+                EditorUtility.SetDirty(thingToDirty);
+                Undo.RegisterCompleteObjectUndo(thingToDirty, "Timeline " + operation);
+            }
+#endif
+        }
+
+        [Conditional("UNITY_EDITOR")]
+        public static void RegisterCreatedObjectUndo(Object thingCreated, string operation)
+        {
+#if UNITY_EDITOR
+            if (DisableUndoGuard.enableUndo)
+            {
+                Undo.RegisterCreatedObjectUndo(thingCreated, "Timeline " + operation);
+            }
+#endif
+        }
+
+#if UNITY_EDITOR
+        public struct DisableUndoGuard : IDisposable
+        {
+            internal static bool enableUndo = true;
+            static readonly Stack<bool> m_UndoStateStack = new Stack<bool>();
+            bool m_Disposed;
+            public DisableUndoGuard(bool disable)
+            {
+                m_Disposed = false;
+                m_UndoStateStack.Push(enableUndo);
+                enableUndo = !disable;
+            }
+
+            public void Dispose()
+            {
+                if (!m_Disposed)
+                {
+                    if (m_UndoStateStack.Count == 0)
+                    {
+                        Debug.LogError("UnMatched DisableUndoGuard calls");
+                        enableUndo = true;
+                        return;
+                    }
+                    enableUndo = m_UndoStateStack.Pop();
+                    m_Disposed = true;
+                }
+            }
+        }
+#endif
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs.meta
new file mode 100644
index 0000000..c62c751
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs.meta
@@ -0,0 +1,11 @@
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diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/WeightUtility.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/WeightUtility.cs
new file mode 100644
index 0000000..22db909
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/WeightUtility.cs
@@ -0,0 +1,30 @@
+using UnityEngine.Playables;
+
+namespace UnityEngine.Timeline
+{
+    static class WeightUtility
+    {
+        // Given a mixer, normalizes the mixer if required
+        //  returns the output weight that should be applied to the mixer as input
+        public static float NormalizeMixer(Playable mixer)
+        {
+            if (!mixer.IsValid())
+                return 0;
+            int count = mixer.GetInputCount();
+            float weight = 0.0f;
+            for (int c = 0; c < count; c++)
+            {
+                weight += mixer.GetInputWeight(c);
+            }
+
+            if (weight > Mathf.Epsilon && weight < 1)
+            {
+                for (int c = 0; c < count; c++)
+                {
+                    mixer.SetInputWeight(c, mixer.GetInputWeight(c) / weight);
+                }
+            }
+            return Mathf.Clamp01(weight);
+        }
+    }
+}
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/WeightUtility.cs.meta b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/WeightUtility.cs.meta
new file mode 100644
index 0000000..bf2c55d
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/WeightUtility.cs.meta
@@ -0,0 +1,11 @@
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