com.misaki.hdrp-toon/Editor/Inspector/Helper/ConverterInitializer.cs

using System;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;

namespace Misaki.HdrpToon.Editor
{
    public class ConverterInitializer
    {
        [InitializeOnLoadMethod]
        public static void Initialize()
        {
            ConverterHelper.RegisterTwoSideConverter<Vector3, Quaternion>(
                nameof(QuaternionToVector3Converter),
                QuaternionToVector3Converter.ConvertTo,
                QuaternionToVector3Converter.ConvertBack);
        }
    }

    public static class ConverterHelper
    {
        public static void RegisterTwoSideConverter<TSource, TResult>(string groupName, Func<TSource, TResult> convertTo, Func<TResult, TSource> convertBack)
        {
            var converterGroup = new ConverterGroup(groupName);
            converterGroup.AddConverter((ref TSource v) => convertTo(v));
            converterGroup.AddConverter((ref TResult v) => convertBack(v));
            ConverterGroups.RegisterConverterGroup(converterGroup);
        }

        public static void RegisterOneSideConverter<T1, T2>(string groupName, Func<T1, T2> convertTo)
        {
            var converterGroup = new ConverterGroup(groupName);
            converterGroup.AddConverter((ref T1 v) => convertTo(v));
            ConverterGroups.RegisterConverterGroup(converterGroup);
        }
    }
}