Create Lightmap UV

using System;
using UnityEngine;

namespace sc.modeling.splines.runtime.auxiliary
{
    [ExecuteAlways]
    public class SplineMesherLightmapUV : MonoBehaviour
    {
        [Tooltip("Let Unity automatically create a new UV (slow but accurate)")]
        public bool autoUnwrap = true;
        public SplineMesher splineMesher;

        private void Reset()
        {
            splineMesher = GetComponent<SplineMesher>();
        }

        private void OnEnable()
        {
            //Subscribe
            SplineMesher.onPostRebuildMesh += OnPostRebuild;
        }

        private void OnPostRebuild(SplineMesher instance)
        {
            //Is the instance being rebuild the one we want to work with
            if (instance == splineMesher)
            {
                MeshFilter mf = splineMesher.GetComponent<MeshFilter>();

                if (mf)
                {
                    #if UNITY_EDITOR
                    if (autoUnwrap)
                    {
                        UnityEditor.Unwrapping.GenerateSecondaryUVSet(mf.sharedMesh);
                    }
                    else
                    {
                        mf.sharedMesh.uv2 = mf.sharedMesh.uv;
                    }
                    #endif
                }
            }
        }

        private void OnDisable()
        {
            //Unsubscribe
            SplineMesher.onPostRebuildMesh -= OnPostRebuild;
        }
    }
}