【引擎触发】attackdamage：攻击前触发的伤害修正

---attackdamage: 人物攻击前触发
function attackdamage(self, Target, Hiter, MagicId)
    local player = class(self)
    if not player then return end
    -- 吸血属性：伤害的 8% 转化为生命
    local lifesteal = tonumber(getplayvar(self, 2, "Lifesteal")) or 0
    if lifesteal > 0 and Target then
        local heal = math.floor(MagicId * 0 + lifesteal)
        humanhp(self, "+", heal)
        sendmsg(self, 1, "吸血回复 " .. heal .. " 点")
    end
end

---反伤：受击方的回弹标记
function Damage.thorns(actor, attacker, dmg)
    local player = class(actor)
    if not player then return end
    local thorns = tonumber(getplayvar(actor, 2, "Thorns")) or 0
    if thorns <= 0 or not attacker then return end
    -- 反伤为受到伤害的 15%，不超过 200 点
    local back = math.min(math.floor(dmg * 0.15), 200)
    setplayvar(attacker, 2, "PendingThorns", back, 0)
    sendmsg(actor, 1, "反伤预备 " .. back .. " 点")
end