凛冬已至：开一片下不完的冰雪领域

fx-frostwinter

flowchart LR
    A["SL:Require 加载模块"] --> B["SL:Schedule(0.02s)<br/>领域主循环"]
    A --> C["SL:RegisterLUAEvent<br/>出视口清理"]
    B --> D["落晶粒子生成"]
    B --> E["冻结节拍判定"]
    B --> F["减速标记"]
    D --> G["领域到期<br/>注销调度器"]
    E --> G
    F --> G
    C --> G

local FrostWinter = {}
local CONST = { DURATION = 4, RADIUS = 150, TICK = 1.0 }

function FrostWinter.Cast(myID)
    -- 领域本体: 以施法者为中心
    FrostWinter._x = SL:GetValue("ACTOR_POSITION_X", myID)
    FrostWinter._y = SL:GetValue("ACTOR_POSITION_Y", myID)
    FrostWinter._left = CONST.DURATION
    FrostWinter._tick = 0

    -- 幂尔主循环: 每帧滴答, 领域的心跳
    if not FrostWinter._schedID then
        FrostWinter._schedID = SL:Schedule(function(dt)
            FrostWinter:Update(dt)
        end, 0.02)
    end
    SL:ShowSystemTips("凛冬已至")
end

function FrostWinter:Update(dt)
    self._left = self._left - dt
    if self._left <= 0 then
        self:Finish()
        return
    end
    -- 冻结节拍: 圈内怪物每秒判一次
    self._tick = self._tick + dt
    if self._tick >= CONST.TICK then
        self._tick = self._tick - CONST.TICK
        local list = SL:GetValue("FIND_IN_VIEW_MONSTER_LIST") or {}
        for _, id in ipairs(list) do
            local mx = SL:GetValue("ACTOR_POSITION_X", id)
            local my = SL:GetValue("ACTOR_POSITION_Y", id)
            if math.sqrt((mx - self._x) ^ 2 + (my - self._y) ^ 2) <= CONST.RADIUS then
                SL:SendLuaNetMsg(0, id, 0, 0, "")   -- 冻结结算走框架消息
            end
        end
    end
end

function FrostWinter:Finish()
    if self._schedID then
        SL:UnSchedule(self._schedID)                 -- 对称注销: 领域亡心跳停
        self._schedID = nil
    end
end

-- 出视口清理: 目标没了领域也别空转
SL:RegisterLUAEvent(LUA_EVENT_ACTOR_OUT_OF_VIEW, "FrostWinter", function(data)
    FrostWinter:Finish()
end)

return FrostWinter