冰锥如雨：从天砸到地的三秒

fx-icespikes

function iceRoar:Cast(zoneX, zoneR)
    self._zone = { x = zoneX, r = zoneR }
    self._t = 0
    self._frost = CreateFrostGround(zoneX, zoneR)      -- 寒雾预警
    self._left = 3.2
end

function iceRoar:Update(dt)
    self._t = self._t + dt
    self._left = self._left - dt
    if self._left <= 0 then self:Finish(); return end

    if self._t > 0.8 then                              -- 预警后开始落锥
        if math.random() < dt * (self._density / 24) * 11 then
            local tx = self._zone.x + (math.random() * 2 - 1) * self._zone.r
            SpawnFallingSpike(tx, -30, GROUND_Y, 640)  -- 天降冰锥
        end
        if math.random() < dt * 2 then                 -- 冻结节拍
            for _, m in ipairs(GetMonstersInZone(self._zone)) do
                if not m._iced then
                    m._iced = true
                    m:ApplyFrozen(1.6)
                    SpawnIceShell(m)                   -- 冻结蓝罩
                end
            end
        end
    end
end

-- 落地残锥: 渐隐留场
function OnSpikeLand(x, y)
    local stuck = CreateStuckSpike(x, y)
    stuck:FadeOutSlowly(4.5)
    PerformWithDelayGlobal(function() stuck:removeFromParent() end, 4.5)
end