orbit zoom

public Transform player; //main camera
public Transform targetObject; //the object that camera to orbit
public float distance = 10.0f;
public float xSpeed = 250.0f;
public float ySpeed = 120.0f;
public float yMinLimit = -20.0f;
public float yMaxLimit = 80.0f;

private float x = 0.0f;
private float y = 0.0f;
private int xsign = 1;

//[Zoom]
public Vector3 lastZoomPosition;
public float zoomSpeed = 5.0f;

//buckets for caching our touch positions
private Vector2 currTouch1 = Vector2.zero, lastTouch1 = Vector2.zero, currTouch2 = Vector2.zero, lastTouch2 = Vector2.zero;

private float currDist = 0.0f, lastDist = 0.0f, zoomFactor = 0.0f;
//[Zoom]

public void OnTouchMoved()
{
    if (Input.touches.Length == 2) {
        Zoom();
    }else if (Input.touches.Length == 1){
        x += xsign * Input.GetTouch(touch2Watch).deltaPosition.x * xSpeed *0.02f;

            y -= Input.GetTouch(touch2Watch).deltaPosition.y * ySpeed *0.02f;

        y = Mathf.Clamp(y, 0, 90);

        Quaternion rotation = Quaternion.Euler(y, x, 0);
            Vector3 tempDistance = new Vector3(0.0f, 0.0f, -distance);
        Vector3 position = rotation * tempDistance + targetObject.position;

            player.rotation = rotation;
            player.position = position;


    }

}

void Zoom()
{
    //Caches touch positions for each finger
    switch(TouchLogic.currTouch)
    {
        case 0://first touch
                currTouch1 = Input.GetTouch(0).position;
                lastTouch1 = currTouch1 - Input.GetTouch(0).deltaPosition;
                break;
        case 1://second touch
                currTouch2 = Input.GetTouch(1).position;
                lastTouch2 = currTouch2 - Input.GetTouch(1).deltaPosition;
                break;
        }

        if(TouchLogic.currTouch >= 1)
        {
            currDist = Vector2.Distance(currTouch1, currTouch2);
            lastDist = Vector2.Distance(lastTouch1, lastTouch2);
        }
        else
        {
            currDist = 0.0f;
            lastDist = 0.0f;
        }

        //Calculate the zoom magnitude
        zoomFactor = Mathf.Clamp(lastDist - currDist, -30.0f, 30.0f);

        //apply zoom to camera
        player.Translate(Vector3.forward * zoomFactor * zoomSpeed * Time.deltaTime);

    }
}