画地为牢：地上那圈它就是出不去

fx-cage

function shadowCage:Cast(target, duration)
    self._dur = duration                              -- 唯一时长来源
    self._cage = CreateCageVisual(target:GetX(), target:GetY())
    target:SetLocked(duration)                        -- 状态与特效共用 self._dur
    target._cageCenter = { x = target:GetX(), y = target:GetY() }
    target._cageRange = 52
    target._cageVX = 0
end

function shadowCage:Update(dt)
    if not self._cage then return end
    self._dur = self._dur - dt
    if self._dur <= 0 then                            -- 同一帧一起结束
        self._cage:Remove()
        self._cage = nil
        return
    end
    local m = self._target
    m._cageVX = m._cageVX + (math.random() - 0.5) * 900 * dt   -- 慌乱加速
    m._cageVX = m._cageVX * 0.96
    local nx = m:GetX() + m._cageVX * dt
    if math.abs(nx - m._cageCenter.x) > m._cageRange then
        m._cageVX = m._cageVX * -0.75                 -- 撞圈弹回
        m:PlayBumpStagger(0.35)
    else
        m:SetX(nx)
    end
end