# Unity中用觸控控制物體旋轉和放大

``````using UnityEngine;
using System.Collections;
using System.IO;
public class ScaleAndRotate : MonoBehaviour
{
private Touch oldTouch1;  //上次觸控點1(手指1)
private Touch oldTouch2;  //上次觸控點2(手指2)
void Start()
{
}
void Update () {
//沒有觸控
if ( Input.touchCount <= 0 ){
return;
}
//單點觸控， 水平上下旋轉
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);
}
//多點觸控, 放大縮小
Touch newTouch1 = Input.GetTouch (0);
Touch newTouch2 = Input.GetTouch (1);
//第2點剛開始接觸螢幕, 只記錄，不做處理
if( newTouch2.phase == TouchPhase.Began ){
oldTouch2 = newTouch2;
oldTouch1 = newTouch1;
return;
}
//計算老的兩點距離和新的兩點間距離，變大要放大模型，變小要縮放模型
float oldDistance = Vector2.Distance(oldTouch1.position, oldTouch2.position);
float newDistance = Vector2.Distance(newTouch1.position, newTouch2.position);
//兩個距離之差，為正表示放大手勢， 為負表示縮小手勢
float offset = newDistance - oldDistance;
//放大因子， 一個畫素按 0.01倍來算(100可調整)
float scaleFactor = offset / 100f;
Vector3 localScale = transform.localScale;
Vector3 scale = new Vector3(localScale.x   scaleFactor,
localScale.y   scaleFactor,
localScale.z   scaleFactor);
//最小縮放到 0.3 倍
if (scale.x > 0.3f && scale.y > 0.3f && scale.z > 0.3f) {
transform.localScale = scale;
}
//記住最新的觸控點，下次使用
oldTouch1 = newTouch1;
oldTouch2 = newTouch2;
}
}``````