打蛇七寸：找对了地方才叫疼

fx-weakspot

local WeakSpot = {}
local KEY = { HIT_R = 14 }

local spot = { phase = 0 }

function Weak.Update(dt)
    -- 七寸在头胸之间正弦游走
    spot.phase = spot.phase + dt * 1.4
    spot.y = -95 + math.sin(spot.phase) * 38
    local target = SL:GetValue("curTarget")
    SL:SetFxPos("weak_ring",
        SL:GetValue("actorX", target),
        SL:GetValue("actorY", target) + spot.y)
end

function Weak.OnAttackHit(hitY)
    local target = SL:GetValue("curTarget")
    local spotY = SL:GetValue("actorY", target) + spot.y
    local base = 10
    local mult = SL:GetValue("weakMult") or 3
    if math.abs(hitY - spotY) <= KEY.HIT_R then
        -- 打中七寸: 三倍疼
        local dmg = base * mult
        SL:DeductHp(target, dmg)
        SL:ShowHitNum(target, dmg, "weak_crit")
        SL:FreezeFrame(0.06)
        SL:PlayActorAct(target, "stuck")
        SL:PlayBurst(SL:GetValue("actorX", target), hitY, "gold", 14)
        SL:PlaySfx("weak_hit")
    else
        -- 打错了: 白给
        SL:DeductHp(target, base)
        SL:ShowHitNum(target, base, "miss_gray")
        SL:PlaySfx("whiff")
    end
end

-- 弱点周期性换位: 每八秒迁往新的高度
function Weak.Relocate()
    SL:ScheduleOnce(function()
        spot.phase = spot.phase + 2.1      -- 相位跳变, 轨迹突变
        Weak.Update(0)
    end, 8)
end

return Weak