using UnityEngine;

public class SmoothZoomCameraFOV : MonoBehaviour
{
    private OnlineMaps map;
    private OnlineMapsTileSetControl control;

    private Camera activeCamera;

    private bool zoomStarted;
    private float lastGestureDistance;
    private float fov;
    private float minFOV;
    private float doubleFOV;

    private void Start()
    {
        map = OnlineMaps.instance;
        control = OnlineMapsTileSetControl.instance;
        activeCamera = control.activeCamera;

        control.allowZoom = false;
        fov = activeCamera.fieldOfView;
        minFOV = fov * 0.3f;
        doubleFOV = fov * 1.2f;
    }

    private void Update()
    {
        if (Input.touchCount == 2)
        {
            Vector2 p1 = Input.GetTouch(0).position;
            Vector2 p2 = Input.GetTouch(1).position;
            float distance = (p1 - p2).magnitude;

            if (!zoomStarted)
            {
                zoomStarted = true;
            }
            else
            {
                float scale = 1;

                if (Mathf.Abs(distance - lastGestureDistance) > 2) scale = distance / lastGestureDistance;

                fov /= scale;
                if (fov < minFOV)
                {
                    fov *= 2;
                    map.zoom++;
                }
                else if (fov > doubleFOV)
                {
                    fov /= 2;
                    map.zoom--;
                }

                activeCamera.fieldOfView = fov;
            }

            lastGestureDistance = distance;
        }
        else
        {
            if (zoomStarted)
            {
                zoomStarted = false;
                lastGestureDistance = 0;
            }
        }
    }
}