滑斩：按住拖多远，刃就送多远

 fx-slidestrike

-- @file SlideStrike.lua
-- 滑斩 —— 按住拖多远，刃就送多远

local SlideStrike = {}

local CONST = {
    MIN_DRAG      = 20,
    DMG_BASE      = 10,
    DMG_PER_STEP  = 0.07,
    DRAG_TO_PUSH  = 1.0,

    COLOR_SLIDE   = "#b87848",
    COLOR_DEEP    = "#4e3014",
    COLOR_GHOST   = "#f0d8b0",

    ZORDER_SLIDE  = 134,
    ZORDER_FX     = 135,
    AUTOINC_BASE  = 1046000,
}

local _dragOn    = false
local _startX    = 0
local _curX      = 0
local _dragFx    = nil
local _scheduler = nil
local _autoInc   = 0

local function GenID(prefix)
    _autoInc = _autoInc + 1
    return string.format("%s_%d", prefix or "SDS2",
        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 StartDrag()
    _dragOn = true
    local myID = SL:GetValue("USER_ID")
    local mp = GetActorPos(myID)
    _startX = mp and (mp.x + 40) or 0
    _curX = _startX
    SL:PlayDragStartFx(myID)
    ShowTip("拖住了——往右拖多远推多远")
end

local function SlideCut(dist)
    local myID = SL:GetValue("USER_ID")
    local tid = SL:GetValue("MARK_TARGET_ID")
    local dmg = CONST.DMG_BASE + math.floor(dist * CONST.DMG_PER_STEP)
    SL:ActorHurt(tid, dmg)
    SL:KnockActor(tid, dist * CONST.DRAG_TO_PUSH)
    SL:PlaySlideCutFx(tid, dist)
    SL:TipAbove(tid, "-" .. dmg)
    ShowTip("滑斩" .. dmg .. "——推出去" .. dist .. "步")
    if SL:GetValue("ACTOR_DEAD", tid) then
        ShowTip("它倒了——拖得远的刃最重")
    end
end

-- 松手：读拖距落刃
function SlideStrike.Release()
    if not _dragOn then return end
    _dragOn = false
    local dist = math.floor(_curX - _startX)
    SafeRemove(_dragFx)
    _dragFx = nil
    if dist < CONST.MIN_DRAG then
        ShowTip("拖太短——刃没送出去")
        return
    end
    SlideCut(dist)
end

-- 定时器：拖线跟手
if not _scheduler then
    _scheduler = SL:Schedule(function()
        if _dragOn then
            local myID = SL:GetValue("USER_ID")
            local mp = GetActorPos(myID)
            if _dragFx and mp then
                GUI:setPosition(_dragFx, mp.x + 40, mp.y - 70)
            end
        end
    end, 0.02)
end

SL:ScheduleOnce(function()
    SL:BindDebugButtonDrag("按住拖刀",
        function(x) _startX = x; _dragOn = true end,
        function(x) _curX = x; SlideStrike.Release() end)
    ShowTip("技能已加载: 滑斩 (调试按钮触发)")
end, 1.0)

function SlideStrike.Unload()
    if _scheduler then SL:Unschedule(_scheduler) end
    SafeRemove(_dragFx)
    _dragOn = false
end

return SlideStrike