牵线：一根线拴俩，跑远了一起挨拽

 fx-tetheryank

-- @file TetherYank.lua
-- 牵线 —— 一根线拴俩，跑远了一起挨拽

local TetherYank = {}

local CONST = {
    TETHER_LEN    = 120,
    SNAP_DMG      = 10,
    CLASH_DMG     = 6,
    SNAP_GAP      = 0.8,
    YANK_CD       = 2.5,
    YANK_DRAG     = 140,

    COLOR_TETHER  = "#b8a030",
    COLOR_DEEP    = "#4e3e10",
    COLOR_GHOST   = "#f0e0a8",

    ZORDER_TETHER = 129,
    ZORDER_FX     = 135,
    AUTOINC_BASE  = 1051000,
}

local _pair       = {}
local _gapT       = 0
local _cdLeft     = 0
local _tetherFx   = nil
local _scheduler  = nil
local _autoInc    = 0

local function GenID(prefix)
    _autoInc = _autoInc + 1
    return string.format("%s_%d", prefix or "TYK",
        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 SnapBack()
    local a = _pair[1]
    local b = _pair[2]
    local mid = (GetActorPos(a).x + GetActorPos(b).x) / 2
    SL:SetActorPos(a, mid - 60, GetActorPos(a).y)
    SL:SetActorPos(b, mid + 60, GetActorPos(b).y)
    SL:ActorHurt(a, CONST.SNAP_DMG)
    SL:ActorHurt(b, CONST.SNAP_DMG)
    SL:TipAbove(a, "绷-10")
    SL:TipAbove(b, "绷-10")
    SL:PlaySnapFx(mid)
    SL:ScreenShake(2.8, 0.18)
    ShowTip("线绷到头——双双回弹各挨十")
end

-- 扯线入口：拖远一只
function TetherYank.Yank()
    if _cdLeft > 0 then
        ShowTip("线在收——" .. string.format("%.1f", _cdLeft) .. "秒")
        return
    end
    local tid = SL:GetValue("MARK_SMALL_ID")
    if not tid then
        ShowTip("没活口——扯不动")
        return
    end
    _cdLeft = CONST.YANK_CD
    local tp = GetActorPos(tid)
    local dir = tp and 1 or -1
    SL:DragActorAway(tid, dir * CONST.YANK_DRAG, 0.4)
    ShowTip("拽出去了——线绷到头有它好看的")
end

-- 定时器：绷直判定与回弹
if not _scheduler then
    _scheduler = SL:Schedule(function(dt)
        if #_pair < 2 then return end
        local a = _pair[1]
        local b = _pair[2]
        if SL:GetValue("ACTOR_DEAD", a)
            or SL:GetValue("ACTOR_DEAD", b) then return end
        local ap = GetActorPos(a)
        local bp = GetActorPos(b)
        if not ap or not bp then return end
        local gap = math.abs(bp.x - ap.x)
        if gap > CONST.TETHER_LEN and _gapT <= 0 then
            _gapT = CONST.SNAP_GAP
            SnapBack()
        end
    end, 0.02)
end

SL:ScheduleOnce(function()
    local a, b = SL:GetSmallPair()
    _pair = { a, b }
    SL:BindDebugButton("扯线", function()
        TetherYank.Yank()
    end)
    ShowTip("技能已加载: 牵线 (调试按钮触发)")
end, 1.0)

function TetherYank.Unload()
    if _scheduler then SL:Unschedule(_scheduler) end
    _pair = {}
end

return TetherYank