using UnityEngine;
using UnityEngine.UI;
using System.Collections;
public class PictureZoom : MonoBehaviour
{
#region Zoom
/// <summary>
/// 上一帧两指间距离
/// </summary>
private float lastDistance = 0;
/// <summary>
/// 当前两个手指之间的距离
/// </summary>
private float twoTouchDistance = 0;
/// <summary>
/// 得到图片
/// </summary>
public RectTransform image;
/// <summary>
/// 第一根手指按下的坐标
/// </summary>
Vector2 firstTouch = Vector3.zero;
/// <summary>
/// 第二根手指按下的坐标
/// </summary>
Vector2 secondTouch = Vector3.zero;
/// <summary>
/// 是否有两只手指按下
/// </summary>
private bool isTwoTouch = false;
[SerializeField, Header("缩放")]
float minExtend = 0.5f;
[SerializeField, Header("扩大")]
float maxExtend = 10.0f;
#endregion
#region Move
// 鼠标起点
private Vector2 originalLocalPointerPosition;
// 面板起点
private Vector3 originalPanelLocalPosition;
// 当前面板
[SerializeField]
private RectTransform panelRectTransform;
// 父节点,这个最好是UI父节点，因为它的矩形大小刚好是屏幕大小
[SerializeField]
private RectTransform parentRectTransform;
private static int siblingIndex = 0;
#endregion
[SerializeField,Header("UI Camera，需要将Canves Render Mode 设置为 ScreenSpace-Camera")]
Camera pressEventCamera;
[SerializeField]
Image images;
[SerializeField]
bool isScrollWheel=false;
[SerializeField]
private float mouseExtendScale = 0.0f;
[SerializeField, Header("鼠标缩放计算")]
bool scrollScaleCal = false;
[SerializeField,Range(1,10)]
int scaleFactor = 3;
void Awake()
{
panelRectTransform = transform.parent as RectTransform;
parentRectTransform = panelRectTransform.parent as RectTransform;
}
// Use this for initialization
void Start()
{
}
private void LateUpdate()
{
#if UNITY_EDITOR || UNITY_STANDALONE_WIN
MouseExtend();
#elif UNITY_IOS || UNITY_ANDROID
TouchExtend();
#endif
}
void MouseExtend()
{
if (isScrollWheel)
{
float scrollValue = Input.GetAxis("Mouse ScrollWheel");
if (scrollValue < 0)
{
if (mouseExtendScale > 0)
{
mouseExtendScale = 0;
}
mouseExtendScale += scrollValue* scaleFactor;
scrollScaleCal = true;
Debug.Log("Zoom Out:\t" + mouseExtendScale);
}
//-Zoom In-//
if (scrollValue > 0)
{
if (mouseExtendScale < 0)
{
mouseExtendScale = 0;
}
mouseExtendScale += scrollValue* scaleFactor;
scrollScaleCal = true;
Debug.Log("Zoom In:\t" + scrollValue);
}
PictureScale();
}
if (Input.GetMouseButtonDown(0))
{
Vector2 mousePostion = Input.mousePosition;
OnPointerDown(mousePostion, pressEventCamera);
}
else if (Input.GetMouseButton(0))
{
Vector2 mousePostion = Input.mousePosition;
OnDrag(mousePostion, pressEventCamera);
}
}
/// <summary>
/// 触摸屏放大缩小
/// </summary>
void TouchExtend()
{
//如果有两个及以上的手指按下
if (Input.touchCount > 1)
{
//当第二根手指按下的时候
if (Input.GetTouch(1).phase == TouchPhase.Began)
{
isTwoTouch = true;
//获取第一根手指的位置
firstTouch = Input.touches[0].position;
//获取第二根手指的位置
secondTouch = Input.touches[1].position;
lastDistance = Vector2.Distance(firstTouch, secondTouch);
}
//如果有两根手指按下
if (isTwoTouch)
{
//每一帧都得到两个手指的坐标以及距离
firstTouch = Input.touches[0].position;
secondTouch = Input.touches[1].position;
twoTouchDistance = Vector2.Distance(firstTouch, secondTouch);
//当前图片的缩放
Vector3 curImageScale = new Vector3(image.localScale.x, image.localScale.y, 1);
//两根手指上一帧和这帧之间的距离差
//因为100个像素代表单位1，把距离差除以100看缩放几倍
float changeScaleDistance = (twoTouchDistance - lastDistance) / 100;
//因为缩放 Scale 是一个Vector3，所以这个代表缩放的Vector3的值就是缩放的倍数
Vector3 changeScale = new Vector3(changeScaleDistance, changeScaleDistance, 0);
//图片的缩放等于当前的缩放加上 修改的缩放
image.localScale = curImageScale + changeScale;
//控制缩放级别
image.localScale = new Vector3(Mathf.Clamp(image.localScale.x, minExtend, maxExtend), Mathf.Clamp(image.localScale.y, minExtend, maxExtend), 1);
//这一帧结束后，当前的距离就会变成上一帧的距离了
lastDistance = twoTouchDistance;
}
//当第二根手指结束时（抬起）
if (Input.GetTouch(1).phase == TouchPhase.Ended)
{
isTwoTouch = false;
firstTouch = Vector3.zero;
secondTouch = Vector3.zero;
}
}
else if (Input.touchCount == 1)
{
Vector2 pos = Input.GetTouch(0).position;
if (Input.GetTouch(0).phase == TouchPhase.Began)
{
if (images)
{
images.color = Color.green;
}
OnPointerDown(pos, pressEventCamera);
}
else if (Input.GetTouch(0).phase == TouchPhase.Moved)
{
if (images)
{
images.color = Color.yellow;
}
OnDrag(pos, pressEventCamera);
}
}
}
/// <summary>
/// 图片缩放核心脚本 Windows 平台放大缩小
/// </summary>
/// <param name="scaleDistance">缩放距离</param>
private void PictureScale()
{
if (scrollScaleCal)
{
//当前图片的缩放
Vector3 curImageScale = new Vector3(image.localScale.x, image.localScale.y, 1);
//两根手指上一帧和这帧之间的距离差
//因为100个像素代表单位1，把距离差除以100看缩放几倍
float changeScaleDistance = mouseExtendScale / 100;
//因为缩放 Scale 是一个Vector3，所以这个代表缩放的Vector3的值就是缩放的倍数
Vector3 changeScale = new Vector3(changeScaleDistance, changeScaleDistance, 0);
//图片的缩放等于当前的缩放加上 修改的缩放
image.localScale = curImageScale + changeScale;
//控制缩放级别
image.localScale = new Vector3(Mathf.Clamp(image.localScale.x, minExtend, maxExtend), Mathf.Clamp(image.localScale.y, minExtend, maxExtend), 1);
scrollScaleCal = false;
}
}
/// <summary>
/// 鼠标、手指摁下获取的位置
/// </summary>
/// <param name="position"></param>
/// <param name="pressEventCamera"></param>
public void OnPointerDown(Vector2 position, Camera pressEventCamera)
{
siblingIndex++;
panelRectTransform.transform.SetSiblingIndex(siblingIndex);
originalPanelLocalPosition = panelRectTransform.localPosition;
RectTransformUtility.ScreenPointToLocalPointInRectangle(parentRectTransform, position, pressEventCamera, out originalLocalPointerPosition);
}
/// <summary>
/// 拖拽功能
/// </summary>
/// <param name="position"></param>
/// <param name="pressEventCamera"></param>
public void OnDrag(Vector2 position, Camera pressEventCamera)
{
if (panelRectTransform == null || parentRectTransform == null)
return;
Vector2 localPointerPosition;
if (RectTransformUtility.ScreenPointToLocalPointInRectangle(parentRectTransform, position, pressEventCamera, out localPointerPosition))
{
Vector3 offsetToOriginal = localPointerPosition - originalLocalPointerPosition;
panelRectTransform.localPosition = originalPanelLocalPosition + offsetToOriginal;
}
ClampToWindow();
}
/// <summary>
/// Clamp panel to area of parent
/// </summary>
void ClampToWindow()
{
Vector3 pos = panelRectTransform.localPosition;
Vector3 minPosition = parentRectTransform.rect.min - panelRectTransform.rect.min;
Vector3 maxPosition = parentRectTransform.rect.max - panelRectTransform.rect.max;
pos.x = Mathf.Clamp(panelRectTransform.localPosition.x, minPosition.x, maxPosition.x);
pos.y = Mathf.Clamp(panelRectTransform.localPosition.y, minPosition.y, maxPosition.y);
panelRectTransform.localPosition = pos;
}
}