using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;

public class AndroidTouch : MonoBehaviour
{
    private Vector3 DefaultPostion;
    private float addValue;
    private float scale;
    private const float maxDis = 6;
    private Touch oldTouch1;  //上次触摸点1(手指1)
    private Touch oldTouch2;  //上次触摸点2(手指2)
    private void Start()
    {
        DefaultPostion = this.transform.position;
    }
    void Update()
    {
        //没有触摸，就是触摸点为0
        if (Input.touchCount <= 0)
        {
            return;
        }
        //单点触摸， 水平上下旋转
        if (1 == Input.touchCount)
        {
            Touch touch = Input.GetTouch(0);
            Vector2 deltaPos = touch.deltaPosition/ 2;
            if (touch.position.x < Screen.width / 2)
            {
                transform.Rotate(Vector3.down * deltaPos.x, Space.Self);//绕Y轴进行旋转
            }
            else
            {
                transform.Rotate(Vector3.right * deltaPos.y, Space.Self);//绕X轴进行旋转，下面我们还可以写绕Z轴进行旋转
            }
            return;                             
        }
        //多点触摸, 放大缩小
        Touch newTouch1 = Input.GetTouch(0);
        Touch newTouch2 = Input.GetTouch(1);
        //第2点刚开始接触屏幕, 只记录，不做处理
        if (newTouch2.phase == TouchPhase.Began)
        {
            oldTouch2 = newTouch2;
            oldTouch1 = newTouch1;
            //addValue = 0;
            return;
        }
        //计算老的两点距离和新的两点间距离，变大要放大模型，变小要缩放模型
        float oldDistance = Vector2.Distance(oldTouch1.position, oldTouch2.position);
        float newDistance = Vector2.Distance(newTouch1.position, newTouch2.position);
        //两个距离之差，为正表示放大手势， 为负表示缩小手势
        float offset = newDistance - oldDistance;
        //放大因子， 一个像素按 0.01倍来算(100可调整)
        float scaleFactor = - offset / 100f;
        addValue += scaleFactor;
        Vector3 localScale = transform.localScale;
        Vector3 scale = new Vector3(localScale.x + scaleFactor,
                                    localScale.y + scaleFactor,
                                    localScale.z + scaleFactor);
        //在什么情况下进行缩放
        if (addValue < maxDis && addValue >0)
        {
            this.transform.position = DefaultPostion + Vector3.forward * addValue;
        }
        else
        {
            CDebug.Log(scale.ToString()  +  "-->" + addValue);
        }
        if (addValue > maxDis)
        {
            addValue = maxDis;
        }
        else if (addValue < 0)
        {
            addValue = 0;
        }
        //记住最新的触摸点，下次使用
        oldTouch1 = newTouch1;
        oldTouch2 = newTouch2;
    }

    public void RefreshPos()
    {
        CDebug.Log("RefreshPos");
        this.transform.position = DefaultPostion;
        //this.transform.eulerAngles = FollowTarget.eulerAngles.y * Vector3.up;
        this.transform.position +=Vector3.forward * scale;
        //this.transform.localScale = this.transform.localScale * scale;
    }
}