UnityのAnimationCurveを自前でシリアライズするためのクラス

AnimationCurveWrapper.cs

using System;
using UnityEngine;
using System.Linq;


[Serializable]
public struct AnimCurveKey
{
#pragma warning disable 0414
	[SerializeField] byte serializedVersion;	// これは3固定
	public float time, value;
	public float inSlope, outSlope;
	[SerializeField] int tangentMode;
	public WeightedMode weightedMode;
	public float inWeight, outWeight;
#pragma warning restore 0414


	public enum TangentMode
	{
		Free = 0,
		Auto = 1,
		Linear = 2,
		Constant = 3,
		ClampedAuto = 4
	}

	public TangentMode LeftTangentMode {
		get => new TangentModeDetail(tangentMode).LeftTangentMode;
		set {
			var tmd = new TangentModeDetail(tangentMode);
			tmd.LeftTangentMode = value;
			tangentMode = tmd.value;
		}
	}
	public TangentMode RightTangentMode {
		get => new TangentModeDetail(tangentMode).RightTangentMode;
		set {
			var tmd = new TangentModeDetail(tangentMode);
			tmd.RightTangentMode = value;
			tangentMode = tmd.value;
		}
	}
	public bool TangentIsBroken {
		get => new TangentModeDetail(tangentMode).IsBroken;
		set {
			var tmd = new TangentModeDetail(tangentMode);
			tmd.IsBroken = value;
			tangentMode = tmd.value;
		}
	}


	// UnityのKeyframeにコンバートする
	public Keyframe Convert()
	{
		return new Keyframe(
			time, value,
			inSlope, outSlope,
			inWeight, outWeight
		) {
		#pragma warning disable 0618
			tangentMode = tangentMode,
		#pragma warning restore 0618
			weightedMode = weightedMode,
		};
	}


	// シリアライズバージョンを決める必要があるので、必ずこれ経由で作成すること
	public AnimCurveKey(
		float time, float value,
		float slope, TangentMode tangentMode
	) {
		serializedVersion = 3;
		this.time = time;
		this.value = value;
		inSlope = outSlope = slope;
		this.tangentMode = new TangentModeDetail{
			LeftTangentMode = tangentMode,
			RightTangentMode = tangentMode,
			IsBroken = false,
		}.value;
		weightedMode = WeightedMode.None;
		inWeight = outWeight = 0;
	}
	public AnimCurveKey(
		float time, float value,
		float inSlope, float outSlope,
		TangentMode leftTangentMode, TangentMode rightTangentMode
	) {
		serializedVersion = 3;
		this.time = time;
		this.value = value;
		this.inSlope = inSlope;
		this.outSlope = outSlope;
		tangentMode = new TangentModeDetail{
			LeftTangentMode = leftTangentMode,
			RightTangentMode = rightTangentMode,
			IsBroken = true,
		}.value;
		weightedMode = WeightedMode.None;
		inWeight = outWeight = 0;
	}


	/** TangentModeのint型から、中身の細かいデータを得るためのもの */
	struct TangentModeDetail
	{
		public int value;

		public TangentMode LeftTangentMode {
			get => (TangentMode)( (value>>1) & 0b111 );
			set => this.value =
				(this.value & 0b1111_0001) |
				((int)value << 1);
		}
		public TangentMode RightTangentMode {
			get => (TangentMode)( (value>>5) & 0b111 );
			set => this.value =
				(this.value & 0b0001_1111) |
				((int)value << 5);
		}
		public bool IsBroken {
			get => (value & 1) != 0;
			set => this.value =
				(this.value & 0b1111_1110) |
				(value ? 1 : 0);
		}

		public TangentModeDetail(int value) => this.value = value;
	}

}



[Serializable]
public struct AnimationCurveWrapper
{
#pragma warning disable 0414
	[SerializeField] byte serializedVersion;	// これは2固定
	[SerializeField] AnimCurveKey[] m_Curve;

	// TODO : これらの使い道を調査する
	[SerializeField] byte m_PreInfinity;
	[SerializeField] byte m_PostInfinity;
	[SerializeField] byte m_RotationOrder;
#pragma warning restore 0414


	static public AnimationCurveWrapper InitValue =>
		new AnimationCurveWrapper(
			new[] {
				new AnimCurveKey(0, 0, 1, AnimCurveKey.TangentMode.Auto),
				new AnimCurveKey(1, 1, 1, AnimCurveKey.TangentMode.Auto),
			}
		);

	public AnimCurveKey[] Keys {
		get => m_Curve;
		set {
			m_Curve = value;
			_nativeAC = null;
		}
	}

	public float Evaluate(float time) => _nativeAC.Evaluate(time);

	// デフォルト値。シリアライズバージョンを決める必要があるので、必ずこれ経由で作成すること
	public AnimationCurveWrapper( AnimCurveKey[] keys ) {
		serializedVersion = 2;
		m_Curve = keys;
		m_PreInfinity = 2;
		m_PostInfinity = 2;
		m_RotationOrder = 4;

		_nativeAC = null;
	}


	AnimationCurve _nativeAC;
	AnimationCurve NativeAC { get { 
		if (_nativeAC == null)
			_nativeAC = new AnimationCurve(
				m_Curve.Select(i => i.Convert()).ToArray()
			) {
			};
		return _nativeAC;
	} }

}