冷却环：转完一圈才能再出手

fx-cooldown

local CooldownRing = {}
local CONST = { KEY = 'CooldownRing' }

function CooldownRing.Start(myID, duration)
    CooldownRing._total = duration
    CooldownRing._left = duration
    CooldownRing._sched = SL:Schedule(function(dt)
        CooldownRing:Update(dt)
    end, 0.02)
end

function CooldownRing:Update(dt)
    self._left = self._left - dt
    if self._left <= 0 then
        SL:UnSchedule(self._sched)
        self._sched = nil
        self._node:FlashReady()
    end
    local ratio = self._left / self._total
    self._ring:SetFillRatio(1 - ratio)
end

return CooldownRing