MRSnowWhite/Assets/_SnowWhite/Scripts/ForestEvent/Bow.cs

using System;
using System.Collections;
using System.Collections.Generic;
using DarkTonic.MasterAudio;
using UnityEngine;

public class Bow : MonoBehaviour
{
    public Transform bowString;
    public Transform bulletPoint;
    public Arrow nowArrow;
    [SoundGroup] public string arrowShoot;

    [Header("箭矢类型管理")]
    private float specialArrowTimeRemaining = 0f;

    [Header("箭矢预制体")]
    public GameObject normalArrowPrefab;

    [Header("弓弦力度参数")]
    public float minForce = 20f;//最小力度
    public float maxForce = 45f;//最大力度
    public float forceMultiplier = 1.2f;//力度倍增系数
    public float maxPullDistance = 0.5f;//弓弦可拉最大距离
    public float forceCurveExponent = 1.5f;//力度曲线指数
    public float currentDrawStrength = 0f;//当前力度（0-1）

    [Header("弓弦视觉反馈")]
    public LineRenderer bowStringRenderer;//弓弦的LineRenderer
    public Transform stringTopPoint;//弓弦顶端点
    public Transform stringBottomPoint;//弓弦末端点
    public Transform stringMiddlePoint;//弓弦中间点（手拉动弓弦的位置）

    private Vector3 middlePointPos;//初始弓弦初始点

    public virtual void Start()
    {
        //初始化弓弦位置
        if (bowStringRenderer != null && stringTopPoint != null && stringBottomPoint != null)
        {
            //设置LineRenderer位置
            bowStringRenderer.positionCount = 3;
            bowStringRenderer.SetPosition(0, stringTopPoint.position);
            bowStringRenderer.SetPosition(1, stringMiddlePoint.position);
            bowStringRenderer.SetPosition(2, stringBottomPoint.position);

            //保存中间点初始位置
            middlePointPos = stringMiddlePoint.localPosition;
        }
    }

    public  void Update()
    {
        UpdateArrowStatus();
        UpdateBowStringVisual();
    }

    //更新弓弦视觉效果
    private void UpdateBowStringVisual()
    {
        if (bowStringRenderer != null && stringTopPoint != null && stringBottomPoint != null && stringMiddlePoint != null)
        {
            //更新LineRenderer
            bowStringRenderer.SetPosition(0, stringTopPoint.position);
            bowStringRenderer.SetPosition(1, stringMiddlePoint.position);
            bowStringRenderer.SetPosition(2, stringBottomPoint.position);
        }
    }

    //更新箭矢状态
    public virtual void UpdateArrowStatus()
    {
        if (nowArrow != null)
        {
            // 箭尾固定点（通常是弓上挂箭点）
            Transform tailPoint = bulletPoint; // 保证箭尾贴在弓上

            // 箭头方向：从箭尾指向左手
            Vector3 direction = (transform.position - tailPoint.position).normalized;

            // 更新箭的位置与旋转
            nowArrow.transform.position = tailPoint.position;
            nowArrow.transform.rotation = Quaternion.LookRotation(direction, transform.up);
        }
    }
    
    Vector3 ProjectPointOnPlane(Vector3 point, Vector3 planeOrigin, Vector3 planeNormal)
    {
        // 单位化法向量
        planeNormal.Normalize();

        // 计算点到平面上任意一点的向量
        Vector3 vectorToPlane = point - planeOrigin;

        // 计算投影距离
        float distance = Vector3.Dot(vectorToPlane, planeNormal);

        // 得到垂足（即点在平面上的投影）
        Vector3 projection = point - distance * planeNormal;

        return projection;
    }

    /// <summary>
    /// 拉弓弦（由左手位置驱动）
    /// </summary>
    public void Pull(Transform point)
    {
        Vector3 planeOrigin = bowString.position;
        Vector3 planeNormal = bowString.right;

        // 投影手的拉动位置到弓弦平面
        Vector3 projectedPoint = ProjectPointOnPlane(point.position, planeOrigin, planeNormal);

        // 转换到弓的局部坐标系
        Vector3 localPos = transform.InverseTransformPoint(projectedPoint);

        // 限制拉弓距离，防止超过最大拉伸范围
        float pullDistance = Mathf.Clamp(localPos.z, -maxPullDistance, 0);

        // 更新弓弦视觉
        if (stringMiddlePoint != null)
        {
            Vector3 midPos = middlePointPos;
            midPos.z = pullDistance;
            stringMiddlePoint.localPosition = midPos;
        }

        // 更新箭尾点位置
        if (bulletPoint != null)
        {
            bulletPoint.localPosition = new Vector3(0, 0, pullDistance);
        }

        // 力度计算
        currentDrawStrength = Mathf.Clamp01(Mathf.Abs(pullDistance) / maxPullDistance);

        // -------------------------
        // ✅ 新增保护逻辑：超过最大拉距时自动复位
        // -------------------------
        // if (Mathf.Approximately(pullDistance, -maxPullDistance))
        // {
        //     Reset();
        // }
    }



    /// <summary>
    /// 弓弦复位
    /// </summary>
    public void Reset()
    {
        // // 拉弓点归零
        // if (bulletPoint != null)
        //     bulletPoint.localPosition = Vector3.zero;
        // 弓弦归位
        if (stringMiddlePoint != null)
            stringMiddlePoint.localPosition = middlePointPos;
        // 当前力度清零
        currentDrawStrength = 0f;
    }


    /// <summary>
    /// 创建箭矢 
    /// </summary>
    public void CreateArrowInHand()
    {
        //如果已有箭矢，先销毁
        if (nowArrow != null)
        {
            Destroy(nowArrow.gameObject);
        }

        //根据当前箭矢类型选择预制体
        GameObject arrowPrefab = normalArrowPrefab;
        GameObject arrowObj = Instantiate(arrowPrefab, bulletPoint);
        nowArrow = arrowObj.GetComponent<Arrow>();

        //初始禁用物理，知道射出
        if (nowArrow.TryGetComponent<Rigidbody>(out var rb))
        {
            rb.isKinematic = true;
        }
    }
    
    /// <summary>
    /// 射出箭矢 
    /// </summary>
    public void ShootArrow()
    {
        if (nowArrow != null)
        {
            MasterAudio.PlaySound(arrowShoot);

            // 根据拉弓力度计算实际力度（应用非线性曲线）
            float curvedStrength = Mathf.Pow(currentDrawStrength, 1.8f);
            float actualForce = Mathf.Lerp(minForce, maxForce, curvedStrength) * forceMultiplier;

            //发射手上已有的箭矢
            nowArrow.transform.SetParent(null);

            //应用物理效果
            if (nowArrow.TryGetComponent<Rigidbody>(out var rb))
            {
                rb.isKinematic = false;//确保物理启用
                rb.velocity = Vector3.zero;//重置速度
                rb.angularVelocity= Vector3.zero;//重置角速度

                //设置初始速度
                rb.AddForce(bulletPoint.forward * actualForce, ForceMode.VelocityChange);
            }

            //调用箭矢初始化（传递力度值）
            nowArrow.OnSpawn(bulletPoint.forward, actualForce);

            //清楚引用
            nowArrow = null;

            Reset();
        }
    }
}