犁地线纹：一道地犁来回耥，耥着它往前挪

 fx-plowline

-- @file PlowLine.lua
-- 犁地线纹 —— 一道地犁来回耥，耥着它往前挪

local PlowLine = {}

local CONST = {
    CREST_LIFE    = 12.0,
    CREST_CD      = 4.0,
    PLOW_SPEED    = 260,
    SWEEP_GAP     = 3.0,
    PLOW_DMG      = 8,
    DRAG_DIST     = 25,

    COLOR_PLOW    = "#789878",
    COLOR_DEEP    = "#2e4828",
    COLOR_GHOST   = "#c8e0c8",

    ZORDER_PLOW   = 90,
    ZORDER_FX     = 135,
    AUTOINC_BASE  = 1119000,
}

local _crestT    = 0
local _cdLeft    = 0
local _plowX     = 0
local _plowOn    = false
local _plowCd    = 0
local _tid       = 0
local _crestFx   = nil
local _scheduler = nil
local _autoInc   = 0

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

function PlowLine.OnField()
    return _plowOn
end

-- 推进与过脚判定：犁线一步一步往前耥
local function StepPlow(dt)
    if not _plowOn then return end
    local tp = GetActorPos(_tid)
    if not tp then
        _plowOn = false
        return
    end
    _plowX = _plowX + CONST.PLOW_SPEED * dt
    if not _hitMark and math.abs(_plowX - tp.x) < 22 then
        _hitMark = true
        SL:ActorHurt(_tid, CONST.PLOW_DMG)
        SL:TipAbove(_tid, "犁-" .. CONST.PLOW_DMG)
        SL:SetPosition(_tid,
            math.max(_homeX + 60, tp.x - CONST.DRAG_DIST))
        SL:PlayPlowFx(_tid)
        ShowTip("犁过它的脚了——拖着它往前挪")
    end
    if _plowX > tp.x + 40 then
        _plowOn = false
        _hitMark = false
    end
end

function PlowLine.Cast()
    if _cdLeft > 0 or _crestT > 0 then return end
    local myID = SL:GetValue("USER_ID")
    local mp = GetActorPos(myID)
    local tid = SL:GetValue("MARK_TARGET_ID")
    if not mp or not tid then return end
    _cdLeft = CONST.CREST_CD
    _crestT = CONST.CREST_LIFE
    _plowX = mp.x + 40
    _plowOn = true
    _plowCd = 0
    _hitMark = false
    _tid = tid
    SafeRemove(_crestFx)
    _crestFx = GUI:Layout_Create(GUI:Attach_Scene(),
        GenID("Plow"), 0, 0, 0, 0, false)
    GUI:setLocalZOrder(_crestFx, CONST.ZORDER_PLOW)
    SL:PlayPlowUpFx(mp.x)
    ShowTip("犁放下了——三秒一耥，耥中拖它上前")
end

-- 定时器：地犁的班次与纹成倒计时
if not _scheduler then
    _scheduler = SL:Schedule(function(dt)
        _cdLeft = math.max(0, _cdLeft - dt)
        if _crestT > 0 then
            _crestT = _crestT - dt
            StepPlow(dt)
            if not _plowOn then
                _plowCd = _plowCd + dt
                if _plowCd >= CONST.SWEEP_GAP then
                    _plowCd = 0
                    _plowOn = true
                    _hitMark = false
                    _plowX = select(1, GetActorPos(
                        SL:GetValue("USER_ID"))).x + 40
                end
            end
            if _crestT <= 0 then
                _plowOn = false
                SafeRemove(_crestFx)
                ShowTip("犁收了——地平了")
            end
        end
    end, 0.02)
end

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

function PlowLine.Unload()
    if _scheduler then SL:Unschedule(_scheduler) end
    SafeRemove(_crestFx)
    _crestT = 0
    _plowOn = false
end

return PlowLine