我的Unity（14）一点一滴VR触屏放大缩小

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 RotateByTouch ()
{
//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;
transform.Rotate (Vector3.down * deltaPos.x, Space.World);//绕Y轴进行旋转
transform.Rotate (Vector3.right * deltaPos.y, Space.World);//绕X轴进行旋转，下面我们还可以写绕Z轴进行旋转
}
//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);
//在什么情况下进行缩放
if (scale.x >= 0.05f && scale.y >= 0.05f && scale.z >= 0.05f) {
transform.localScale = scale;
}
//记住最新的触摸点，下次使用
oldTouch1 = newTouch1;
oldTouch2 = newTouch2;
}