OneHitKillModule.cs

using System;
using BepInEx.Configuration;
using HarmonyLib;
using UnityEngine;
using UnityEngine.InputSystem;

namespace HTFToolkit
{
    /// <summary>
    /// 一击必杀（秒杀生物）。
    /// 主机/单人：Harmony 前缀改写 Creature.ServerChangeHp 的 damage → 任意攻击命中都致命
    ///            （游戏内所有伤害最终都走这个扣血入口：_hp.Value -= damage）。
    /// 客户端：伤害在主机结算，本机 patch 无效 → 走官方零校验 ServerRpc
    ///         Server.HitCreature(creature, player, damage, hitPoint, dir)，左键攻击时对
    ///         准星目标补发一次致命伤害。
    /// ⚠️ Boss 无敌阶段（BossManager.IsImmortal）游戏本身禁止扣血，此时秒杀无效（属游戏机制）。
    /// </summary>
    internal static class OneHitKillModule
    {
        public static bool Enabled;

        /// <summary>致命伤害值（游戏血量远小于此）。</summary>
        private const int LethalDamage = 99999;

        /// <summary>客户端：准星判定最大角度（度）。</summary>
        private static ConfigEntry<float> _aimAngle;
        private static ConfigEntry<float> _maxDistance;

        public static void BindConfig(ConfigFile cfg)
        {
            _aimAngle = cfg.Bind("一击必杀", "准星判定角度", 25f, "客户端模式：准星与生物的最大夹角（度）");
            _maxDistance = cfg.Bind("一击必杀", "最大距离", 120f, "客户端模式：超过该距离不生效");
        }

        public static void ApplyPatches(Harmony harmony)
        {
            try
            {
                var m = AccessTools.Method(typeof(Creature), "ServerChangeHp");
                if (m != null)
                {
                    harmony.Patch(m,
                        prefix: new HarmonyMethod(AccessTools.Method(typeof(OneHitKillModule), nameof(PrefixLethal))));
                }
            }
            catch (Exception e)
            {
                Plugin.Log?.LogWarning($"OneHitKill patch failed: {e.Message}");
            }
        }

        /// <summary>主机/单人：把扣血量放大为致命值（只对正伤害生效，避免把治疗也放大）。</summary>
        private static void PrefixLethal(ref int damage)
        {
            if (Enabled && damage > 0)
                damage = LethalDamage;
        }

        /// <summary>
        /// 客户端：左键攻击时对准星目标补发一次致命伤害。
        /// 由 Plugin.Update 调用（内部自行分流，主机/单人直接短路返回）。
        /// </summary>
        public static void Update()
        {
            if (!Enabled)
                return;
            try
            {
                if (Compat.IsHost || !Compat.ClientRpcReady)
                    return;
                // 游戏用新 Input System（旧 UnityEngine.Input 在本项目不可用）
                Mouse mouse = Mouse.current;
                if (mouse == null || !mouse.leftButton.wasPressedThisFrame)
                    return;

                Creature target = FindAimedCreature();
                if (target == null)
                    return;

                Player p = Player.LocalPlayer;
                if (p == null)
                    return;

                Vector3 hitPoint = target.transform.position;
                Vector3 dir = (hitPoint - p.transform.position).normalized;
                Server.Instance.HitCreature(target, p, LethalDamage, hitPoint, dir);
            }
            catch (Exception e)
            {
                Plugin.Log?.LogWarning($"OneHitKill client: {e.Message}");
            }
        }

        /// <summary>找准星指向的最近活体生物（客户端模式用）。</summary>
        private static Creature FindAimedCreature()
        {
            Camera cam = null;
            try
            {
                cam = GameInfo.CurCamera;
            }
            catch
            {
                cam = null;
            }
            if (cam == null)
                cam = Camera.main;
            if (cam == null)
                return null;

            Player p = Player.LocalPlayer;
            if (p == null)
                return null;

            Vector3 camPos = cam.transform.position;
            Vector3 camFwd = cam.transform.forward;
            float minAlign = Mathf.Cos((_aimAngle?.Value ?? 25f) * Mathf.Deg2Rad);
            float maxSqr = (_maxDistance?.Value ?? 120f);
            maxSqr *= maxSqr;

            Creature best = null;
            float bestScore = float.MaxValue;
            foreach (System.Collections.Generic.KeyValuePair<Transform, Item> kv in ItemManager.Items)
            {
                Item item = kv.Value;
                Creature c = item as Creature;
                if (c == null && item != null)
                    c = item.Creature;
                if (!Compat.CreatureAlive(c))
                    continue;

                Vector3 pos = c.Rig ? c.Rig.worldCenterOfMass : c.transform.position;
                Vector3 to = pos - camPos;
                float sqr = to.sqrMagnitude;
                if (sqr < Mathf.Epsilon || sqr > maxSqr)
                    continue;
                float align = Vector3.Dot(camFwd, to) / Mathf.Sqrt(sqr);
                if (align < minAlign)
                    continue;
                if (sqr < bestScore)
                {
                    bestScore = sqr;
                    best = c;
                }
            }
            return best;
        }
    }
}