using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class sceneContorl : MonoBehaviour
{
    public Camera m_cam;
    public GameObject mainScene;
    private bool m_fingerDown = false;

    // 手指的起始位置
    private Vector2 m_oneFingerDragStartPos;

    // UI元素的 RectTransform
    private RectTransform mainSceneRectTransform;

    // 灵敏度系数
    private float sensitivity = 0.5f; // 可以根据需要调整此值

    // 滑动限制的最小值和最大值
    public float minX = -500f; // 最小x值
    public float maxX = 500f;  // 最大x值

    // Start is called before the first frame update
    void Start()
    {
        mainSceneRectTransform = mainScene.GetComponent<RectTransform>();
    }

    // Update is called once per frame
    void Update()
    {
#if UNITY_EDITOR || UNITY_STANDALONE
        // 桌面端：鼠标按下时
        if (Input.GetMouseButtonDown(0))
        {
            m_fingerDown = true;
            m_oneFingerDragStartPos = Input.mousePosition; // 获取鼠标按下的起始位置
        }

        // 桌面端：鼠标松开时
        if (Input.GetMouseButtonUp(0))
        {
            m_fingerDown = false;
        }

        // 处理鼠标拖动
        if (m_fingerDown)
        {
            HandleFingerDragMove(Input.mousePosition);
        }

#else
        // 移动端：单指滑动
        if (Input.touchCount == 1)
        {
            Touch touch = Input.touches[0];

            // 手指刚触碰屏幕时
            if (touch.phase == TouchPhase.Began)
            {
                m_fingerDown = true;
                m_oneFingerDragStartPos = touch.position; // 获取手指按下的起始位置
            }
            // 手指在屏幕上滑动时
            else if (touch.phase == TouchPhase.Moved)
            {
                HandleFingerDragMove(touch.position); // 处理手指拖动
            }
        }
        else
        {
            m_fingerDown = false;
        }
#endif
    }

    /// <summary>
    /// 单指滑动
    /// </summary>
    private void HandleFingerDragMove(Vector2 fingerPos)
    {
        // 计算当前帧的滑动增量（交换顺序，保证滑动方向一致）
        Vector3 moveDelta = fingerPos - m_oneFingerDragStartPos; // 当前触摸位置 - 起始位置
        Vector3 newPos = mainSceneRectTransform.anchoredPosition;

        // 根据滑动增量计算新的x轴位置，并限制在指定范围内
        newPos.x = newPos.x + (moveDelta.x * sensitivity);

        // 限制x轴位置在 minX 和 maxX 之间
        newPos.x = Mathf.Clamp(newPos.x, minX, maxX);

        mainSceneRectTransform.anchoredPosition = newPos; // 设置新的锚点位置

        // 更新起始位置，用于计算下一帧的增量
        m_oneFingerDragStartPos = fingerPos;
    }
    /// <summary>
    /// 屏幕坐标换算成3D坐标
    /// </summary>
    /// <param name="screenPos">屏幕坐标</param>
    /// <returns></returns>
    Vector3 GetWorldPos(Vector2 screenPos)
    {
        return m_cam.ScreenToWorldPoint(new Vector3(screenPos.x, screenPos.y, Mathf.Abs(m_cam.transform.position.z)));
    }


}