private void DrawDistSelector()
    {
        EditorGUILayout.BeginHorizontal();
        GUILayout.Label("Dist value");
        EditorGUI.BeginChangeCheck();
        float dist = EditorGUILayout.Slider(spline.cDistance, 0f, spline.GetLength(1f));

        if (EditorGUI.EndChangeCheck())
        {
            Undo.RecordObject(spline, "Dist change");
            EditorUtility.SetDirty(spline);
            spline.cDistance = dist;
            spline.t         = spline.GetParametricLength(dist);
        }
        EditorGUILayout.EndHorizontal();
    }