using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Planeouch : MonoBehaviour
{
    //定義兩個（早的）觸控點
    Touch oldTouchOne;
    Touch oldTouchTwo;
    // Use this for initialization
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        switch (Input.touchCount)//判斷觸控點（螢幕上手指）數量
        {
            case 0:
                //沒有手指在螢幕上，return
                return;
            case 1:
                //一個手指在螢幕上，呼叫旋轉函式
                OnePoint();
                break;
            case 2:
                //兩個手指在螢幕上，呼叫放大縮小函式
                TwoPoint();
                break;
        }
    }
    /// <summary>
    /// 一個手指觸控，旋轉函式
    /// </summary>
    void OnePoint()
    {
        //獲取一個手指
        Touch touch = Input.GetTouch(0);
        //獲取這個手指的位置
        Vector2 v2 = touch.deltaPosition;
        //沿著y軸旋轉手指x的改變數
        transform.Rotate(Vector3.back* v2.x, Space.World);
    }
    /// <summary>
    /// 兩個手指觸控，放大縮小函式
    /// </summary>
    void TwoPoint()
    {
        //定義兩個新的觸控點
        Touch newTouchOne = Input.GetTouch(0);
        Touch newTouchTwo = Input.GetTouch(1);
        if (newTouchTwo.phase == TouchPhase.Began)//第二個手指放到螢幕上
        {
            //新的觸控點賦值給早先的觸控點
            oldTouchOne = newTouchOne;
            oldTouchTwo = newTouchTwo;
            return;
        }
        //早先的兩個觸控點（手指）之間的距離
        float oldDistance = Vector2.Distance(oldTouchOne.position, oldTouchTwo.position);
        //新的（兩個手指觸控位置改變後）的兩個觸控點（手指）之間的距離
        float newDistance = Vector2.Distance(newTouchOne.position, newTouchTwo.position);
        //兩個距離的差值/1000
        float offset = (newDistance - oldDistance) / 1000;//差值/1000
        //定義一個v3型別變數LocalScal，用來記錄物體的localScale
        Vector3 LocalScal = transform.localScale;
        //定義一個v3型別變數scal，它等於上一個的LocalScal變數加上兩個距離的差值
        Vector3 scal = new Vector3(LocalScal.x + offset, LocalScal.y + offset, LocalScal.z + offset);
        //如果物體的scal大於或等於0.25（也就是物體最小和縮小到0.25）
        if (scal.x >= 0.25f && scal.y >= 0.25f && scal.z >= 0.25f)
        {
            transform.localScale = scal;//把scal賦值給物體的localScale
        }
        //記錄新的觸控點為老的觸控點
        oldTouchOne = newTouchOne;
        oldTouchTwo = newTouchTwo;
    }
}