毒雾弥漫：站在里面就一直掉血

fx-poison

local poisonZone = {}

function poisonZone:Init(x, y, radius)
    self._x, self._y, self._r = x, y, radius
    self._flat = 0.5                                -- 椭圆压扁比: 判定绘制同源
    self._node = CreatePoisonGround(x, y, radius)   -- 地面层
    self._node:AddToLayer(GROUND_LAYER)
end

function poisonZone:Contains(actor)
    local dx = actor:GetX() - self._x
    local dy = (actor:GetY() - self._y) / self._flat
    return math.sqrt(dx * dx + dy * dy) <= self._r
end

function poisonZone:Update(dt)
    for _, actor in ipairs(scene:GetActors()) do
        if self:Contains(actor) then
            actor.poisonAcc = (actor.poisonAcc or 0) + dt
            if actor.poisonAcc >= 1 then            -- 每秒一跳
                actor.poisonAcc = actor.poisonAcc - 1
                actor:ApplyPoison(8)
                actor:ShowPoisonAura()              -- 中毒状态罩
            end
        else
            actor.poisonAcc = 0                     -- 出去立刻清零
        end
    end
end