开天斩：从天而降的那把大剑

fx-giantsword

function skySword:Cast(x, y)
    self._x, self._y = x, y
    self._phase, self._t = 'warn', 0
    self._shadow = CreateShadowWarning(x, y, 0.9)      -- 影子预警 0.9s
    self._shadow:GrowTo(SWORD_W * 3)                   -- 长到剑的横截面
end

function skySword:Update(dt)
    self._t = self._t + dt
    if self._phase == 'warn' and self._t >= 0.9 then
        self._phase, self._t = 'fall', 0
    elseif self._phase == 'fall' then
        local p = math.min(1, self._t / 0.24)
        self._swordY = -320 + p * (320 - SWORD_LEN * 0.5)
        if p >= 1 then
            self._phase, self._t = 'stuck', 0
            SpawnShockwave(self._x, self._y)           -- 扩散冲击波
            ScreenShake(0.5)
            for _, m in ipairs(GetMonstersNearX(self._x, 90)) do
                m:OnHit(self._dmg)
            end
        end
    elseif self._phase == 'stuck' and self._t >= 2.2 then
        self:Remove()                                  -- 渐隐拔走
    end
end