认踪矢纹：箭认准了影，拐着弯也要追上

flowchart TD
A[点认踪] --> B[矢出鞘 朝正前]
B --> C[每拍箭头挪一点]
C --> D{追上怪了吗}
D -- 追上 --> E[咬中二十四]
D -- 没追上 --> F{飞满三秒了吗}
F -- 没有 --> C
F -- 飞累了 --> G[坠地收矢]
E --> H[六秒后再射]
G --> H

-- @file CrestHoming.lua
-- 认踪矢纹 —— 箭认准了影 拐着弯也要追上

local CrestHoming = {}

local CONST = {
    ARROW_SPEED   = 300,
    TURN_RATE     = 4,
    HOMING_DMG    = 24,
    TIRED_TIME    = 3,
    ARROW_CD      = 6,

    AUTOINC_BASE  = 1206300,
}

local _flying   = false
local _x        = 0
local _y        = 0
local _ang      = 0
local _t        = 0
local _cd       = 0
local _autoInc  = 0

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

local function GenID()
    _autoInc = _autoInc + 1
    return CONST.AUTOINC_BASE + _autoInc
end

function CrestHoming.Flying() return _flying end

-- 射矢: 出鞘朝正前
function CrestHoming.Shoot()
    if _cd > 0 then
        ShowTip("箭庐还在制矢——再等" .. math.ceil(_cd) .. "秒")
        return
    end
    _cd = CONST.ARROW_CD
    _flying = true
    _x = 226
    _y = 180
    _ang = 0
    _t = 0
    ShowTip("认踪矢出——拐着弯也要追上")
end

-- 每拍推进: 逐拍微转向 追上收矢
if not _ticker then
    _ticker = SL:Schedule(function(dt)
        if _cd > 0 then _cd = _cd - dt end
        if not _flying then return end
        _t = _t + dt
        if _t >= CONST.TIRED_TIME then
            _flying = false
            ShowTip("矢飞累了——坠地没咬着")
            return
        end
        local dx = (SL:GetValue("mobX") or 0) - 8 - _x
        local dy = (SL:GetValue("mobHeadY") or 0) - _y
        local want = math.atan(dy, dx)
        local diff = want - _ang
        while diff > 3.14 do diff = diff - 6.28 end
        while diff < -3.14 do diff = diff + 6.28 end
        local step = math.max(-4 * dt, math.min(4 * dt, diff))
        _ang = _ang + step
        _x = _x + math.cos(_ang) * CONST.ARROW_SPEED * dt
        _y = _y + math.sin(_ang) * CONST.ARROW_SPEED * dt
        if math.sqrt(dx * dx + dy * dy) < 20 then
            _flying = false
            ShowTip("咬中" .. CONST.HOMING_DMG .. "!")
        end
    end, 0.02)
end

SL:ScheduleOnce(function()
    SL:BindDebugButton("认踪!", function()
        CrestHoming.Shoot()
    end)
    ShowTip("技能已加载: 认踪矢纹")
end, 1.0)

function CrestHoming.Unload()
    if _ticker then SL:Unschedule(_ticker) end
    _flying = false
end

return CrestHoming