【引擎触发】herolevelup：英雄升级的培养线

---herolevelup: 英雄升级触发 play:主人对象
function herolevelup(play)
    local player = class(play)
    if not player then return end
    local lv = Hero.levelOf(play)
    -- 英雄每级成长：攻击与防御的成长值
    setplayvar(play, 2, "HeroAtkUp", lv * 3, 1)
    -- 每 10 级的英雄技能解锁
    local skill = HERO_SKILLS[lv]
    if skill then
        local sid = getskillindex(skill.name)
        addskill(play, sid)
        sendmsg(play, 1, "英雄领悟 " .. skill.name .. "！")
    end
end

---英雄技能表：等级与职业的解锁
HERO_SKILLS = {
    [15] = { name = "白虎啸" },
    [25] = { name = "月灵护主" },
    [35] = { name = "合击·雷霆一击" },
}

---合击技能：主人与英雄的协同
function Hero.comboSkill(actor, targetId)
    local player = class(actor)
    if not player then return false end
    local heroLv = Hero.levelOf(actor)
    if heroLv < 35 then
        sendmsg(actor, 1, "英雄 35 级解锁合击")
        return false
    end
    -- 合击的冷却 30 秒，威力按双方攻击之和
    local cd = tonumber(getplayvar(actor, 2, "ComboCD")) or 0
    if os.time() - cd < 30 then
        sendmsg(actor, 1, "合击冷却中")
        return false
    end
    setplayvar(actor, "HUMAN", "ComboCD", os.time(), 0)
    local dmg = Hero.comboDamage(actor, targetId)
    sendmsg(actor, 1, "合击·雷霆一击造成 " .. dmg .. " 伤害！")
    return true
end