Unity中用触摸控制物体旋转和放大

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;      }    }