Reproject Spline

using System;
using System.Linq;
using UnityEngine;
using UnityEngine.Splines;

namespace sc.modeling.splines.runtime.auxiliary
{
    //Samples the source spline at regular intervals and creates a new spline from the data
    //Negatives the unwanted side effects of scaling a SplineContainer
    [ExecuteAlways]
    public class ReprojectSpline : MonoBehaviour
    {
        public SplineContainer source;
        public SplineContainer destination;

        public float knotDistance = 2f;

        private void Reset()
        {
            destination = GetComponent<SplineContainer>();
        }

        private void OnEnable()
        {
            Spline.Changed += OnSplineChanged;
            Resample();
        }

        private void OnDisable()
        {
            Spline.Changed -= OnSplineChanged;
        }

        private void OnSplineChanged(Spline spline, int index, SplineModification modificationType)
        {
            if (!source) return;

            if (spline.GetHashCode() != source.GetHashCode()) return;

            //Spline belongs to the assigned container?
            var splineIndex = Array.IndexOf(source.Splines.ToArray(), spline);
            if (splineIndex < 0)
                return;

            Resample();
        }

        public void Resample()
        {
            if (!source || !destination) return;

            for (int s = 0; s < destination.Splines.Count; s++)
            {
                destination.RemoveSplineAt(s);
            }

            for (int i = 0; i < source.Splines.Count; i++)
            {
                Spline spline = new Spline();
                float length = source.Splines[i].CalculateLength(source.transform.localToWorldMatrix);


                int sampleCount = Mathf.CeilToInt(length / knotDistance);
                for (int j = 0; j <= sampleCount; j++)
                {
                    float t = (float) j / sampleCount;

                    t = Mathf.Clamp(t, 0.001f, 0.999f);
                    source.Splines[i].Evaluate(t, out var position, out var tangent, out var up);
                    position = source.transform.TransformPoint(position);
                    position = destination.transform.InverseTransformPoint(position);

                    BezierKnot knot = new BezierKnot();
                    knot.Position = position;

                    spline.Add(knot, TangentMode.Continuous);
                }

                //Automatically recalculate tangents
                spline.SetTangentMode(new SplineRange(0, spline.Count), TangentMode.AutoSmooth);
                spline.Closed = source.Splines[i].Closed;

                destination.AddSpline(spline);
            }
        }
    }
}