酸雨：酸雨落下来，站在里面持续掉血

 fx-acidrain

-- @file AcidRain.lua
-- 酸雨 —— 酸雨落下来站在里面持续掉血

local AcidRain = {}

local CONST = {
    RAIN_LIFE     = 6.0,
    RAIN_TICK     = 0.5,
    RAIN_DMG      = 6,
    RAIN_RADIUS   = 80,
    RAIN_CD       = 5.0,

    COLOR_RAIN    = "#78b868",
    COLOR_DEEP    = "#1e4a28",
    COLOR_GHOST   = "#c8ecd0",

    ZORDER_RAIN   = 128,
    ZORDER_FX     = 135,
    AUTOINC_BASE  = 1066000,
}

local _rainT     = 0
local _rainX     = 0
local _tickT     = 0
local _cdLeft    = 0
local _rainFx    = nil
local _scheduler = nil
local _autoInc   = 0

local function GenID(prefix)
    _autoInc = _autoInc + 1
    return string.format("%s_%d", prefix or "ADN",
        CONST.AUTOINC_BASE + _autoInc)
end

local function GetActorPos(id)
    if not id then return nil end
    local x = SL:GetValue("ACTOR_POSITION_X", id)
    local y = SL:GetValue("ACTOR_POSITION_Y", id)
    if not x or not y then return nil end
    return { x = x, y = y }
end

local function SafeRemove(node)
    if node and not GUI:Widget_IsNull(node) then
        GUI:removeFromParent(node)
    end
end

local function ShowTip(msg)
    if msg and msg ~= "" then SL:ShowSystemTips(msg) end
end

local function RainTick(tid)
    local tp = GetActorPos(tid)
    if not tp then return end
    if math.abs(tp.x - _rainX) <= CONST.RAIN_RADIUS then
        SL:ActorHurt(tid, CONST.RAIN_DMG)
        SL:TipAbove(tid, "酸-6")
        SL:PlayAcidTickFx(tid)
    end
end

function AcidRain.Cast()
    if _cdLeft > 0 or _rainT > 0 then return end
    local tid = SL:GetValue("MARK_TARGET_ID")
    local tp = GetActorPos(tid)
    if not tid or not tp then return end
    _cdLeft = CONST.RAIN_CD
    _rainT = CONST.RAIN_LIFE
    _rainX = tp.x
    SafeRemove(_rainFx)
    _rainFx = GUI:Layout_Create(GUI:Attach_SceneF(),
        GenID("Rain"), _rainX, tp.y, 0, 0, false)
    GUI:setLocalZOrder(_rainFx, CONST.ZORDER_RAIN)
    SL:PlayRainStartFx(_rainX)
    SL:TipAbove(tid, "酸雨！")
    ShowTip("酸雨落了——六秒的雨区，站里面掉血")
end

-- 定时器：雨期倒计时与持续结算
if not _scheduler then
    _scheduler = SL:Schedule(function(dt)
        _cdLeft = math.max(0, _cdLeft - dt)
        if _rainT > 0 then
            _rainT = _rainT - dt
            _tickT = _tickT + dt
            if _rainFx then
                GUI:setPosition(_rainFx, _rainX,
                    GetActorPos(SL:GetValue("MARK_TARGET_ID"))
                    and select(2, GetActorPos(
                        SL:GetValue("MARK_TARGET_ID"))) or 0)
            end
            if _tickT >= CONST.RAIN_TICK then
                _tickT = 0
                local tid = SL:GetValue("MARK_TARGET_ID")
                if tid and not SL:GetValue("ACTOR_DEAD", tid) then
                    RainTick(tid)
                end
            end
            if _rainT <= 0 then
                SafeRemove(_rainFx)
                _rainFx = nil
                ShowTip("雨停了——酸雨区域消散")
            end
        end
    end, 0.02)
end

SL:ScheduleOnce(function()
    SL:BindDebugButton("酸雨", function()
        AcidRain.Cast()
    end)
    ShowTip("技能已加载: 酸雨 (调试按钮触发)")
end, 1.0)

function AcidRain.Unload()
    if _scheduler then SL:Unschedule(_scheduler) end
    SafeRemove(_rainFx)
    _rainT = 0
    _tickT = 0
end

return AcidRain