Unity中用触摸控制物体旋转和放大

1. using UnityEngine;
   using System.Collections;
   using System.IO;

   public class ScaleAndRotate : MonoBehaviour
   {
   private Touch oldTouch1; //上次触摸点1(手指1)
   private Touch oldTouch2; //上次触摸点2(手指2)

   void Start()
   {

   }

   void Update () {

   //没有触摸
   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;
   transform.Rotate(Vector3.down * deltaPos.x , Space.World);
   transform.Rotate(Vector3.right * deltaPos.y , Space.World);
   }

   //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;
   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;
   Vector3 localScale = transform.localScale;
   Vector3 scale = new Vector3(localScale.x + scaleFactor,
   localScale.y + scaleFactor,
   localScale.z + scaleFactor);

   //最小缩放到 0.3 倍
   if (scale.x > 0.3f && scale.y > 0.3f && scale.z > 0.3f) {
   transform.localScale = scale;
   }

   //记住最新的触摸点，下次使用
   oldTouch1 = newTouch1;
   oldTouch2 = newTouch2;
   }

   }