技能开槽：等级解锁的技能栏扩展

-- 错误：开局全开，新手乱放高阶技能
for i = 1, SLOTS do
    slot[i]:setTouchEnabled(true)
end

local SLOTS = 10
local function refreshBar()
    local lv = myLevel or 1
    for i = 1, SLOTS do
        local need = math.floor((i - 1) / 2) * 5 + 1
        local slot = bar:getChildByName("slot" .. i)
        slot:getChildByName("lock"):setVisible(lv < need)
        slot:setTouchEnabled(lv >= need)
    end
end