Smooth map moving between two geo points

using UnityEngine;

namespace InfinityCode.OnlineMapsExamples
{
    /// <summary>
    /// Example of a smooth movement to current GPS location.
    /// </summary>
    [AddComponentMenu("Infinity Code/Online Maps/Examples (API Usage)/SmoothMoveExample")]
    public class SmoothMoveExample : MonoBehaviour
    {
        /// <summary>
        /// Move duration (sec)
        /// </summary>
        public float time = 3;

        /// <summary>
        /// Relative position (0-1) between from and to
        /// </summary>
        private float angle;

        /// <summary>
        /// Movement trigger
        /// </summary>
        private bool isMovement;

        private Vector2 fromPosition;
        private Vector2 toPosition;
        private double fromTileX, fromTileY, toTileX, toTileY;
        private int moveZoom;


        private void OnGUI()
        {
            // On click button, starts movement
            if (GUI.Button(new Rect(5, 5, 100, 30), "Goto marker"))
            {
                // from current map position
                fromPosition = OnlineMaps.instance.position;

                // to GPS position;
                toPosition = OnlineMapsLocationService.instance.position;

                // calculates tile positions
                moveZoom = OnlineMaps.instance.zoom;
                OnlineMaps.instance.projection.CoordinatesToTile(fromPosition.x, fromPosition.y, moveZoom, out fromTileX, out fromTileY);
                OnlineMaps.instance.projection.CoordinatesToTile(toPosition.x, toPosition.y, moveZoom, out toTileX, out toTileY);

                // if tile offset < 4, then start smooth movement
                if (OnlineMapsUtils.Magnitude(fromTileX, fromTileY, toTileX, toTileY) < 4)
                {
                    // set relative position 0
                    angle = 0;

                    // start movement
                    isMovement = true;
                }
                else // too far
                {
                    OnlineMaps.instance.position = toPosition;
                }
            }
        }

        private void Update()
        {
            // if not movement then return
            if (!isMovement) return;

            // update relative position
            angle += Time.deltaTime / time;

            if (angle > 1)
            {
                // stop movement
                isMovement = false;
                angle = 1;
            }

            // Set new position
            double px = (toTileX - fromTileX) * angle + fromTileX;
            double py = (toTileY - fromTileY) * angle + fromTileY;
            OnlineMaps.instance.projection.TileToCoordinates(px, py, moveZoom, out px, out py);
            OnlineMaps.instance.SetPosition(px, py);
        }
    }
}