冰冻术：把怪钉在原地的定身节奏

freeze

local BuffEntityFreezed = class("BuffEntityFreezed", BuffEntity)

function BuffEntityFreezed:onAdd(actor)
    self.super.onAdd(self, actor)
    self.remain = 3.0                  -- 定身 3 秒
    self.hits   = 0
    actor:SetMoveLocked(true)          -- 没收移动权限
    actor:PlayFreezeEffect(true)       -- 冰层表现
end

function BuffEntityFreezed:onHit(dmg)
    self.hits = self.hits + 1
    if self.hits >= 3 then             -- 受击三次提前破冰
        self.remain = 0
    end
end

function BuffEntityFreezed:onTick(dt)
    self.remain = self.remain - dt     -- 帧率无关的倒计时
    if self.remain <= 0 then
        self:remove()                  -- 到点自毁, 走 onRemove
    end
end

function BuffEntityFreezed:onRemove(actor)
    actor:SetMoveLocked(false)         -- 归还移动权限
    actor:PlayFreezeEffect(false)
    actor:PlayThawAnimation()          -- 碎冰动画收尾
    self.super.onRemove(self, actor)
end