enum enemyType                        //设置好飞机的类型~

{

    ENEMY_MIN = 1,

    ENEMY_MED,

    ENEMY_MAX

};

const int ENEMY_MIN_LIFE = 1;             //设置飞机的生命值~

const int ENEMY_MED_LIFE = 7;

const int ENEMY_MAX_LIFE = 20;

const int ENEMY_MIN_COUNT = 30;               //设置飞机的同时在屏幕的最大数量~

const int ENEMY_MED_COUNT = 10;

const int ENEMY_MAX_COUNT = 5;

Vector<Enemy*> _enemyArray1;      //存飞机的~

    float _minDuration, _maxDuration;         //敌机飞过去的时间

    CC_SYNTHESIZE(float, _enemy1SpawRate, _enemy1SpawRate);      //定义下敌机飞过去的速度~

    float _timeSum1;           //到时就知道啦~

    void initEnemy1();            //初始化enemy1

    void spawEnemy1(float dt);           //发射enemy1

    void spawEnemy(float dt);          //这是总的函数，下面就是控制发射3钟不同的飞机

    Enemy* getAvailableEnemy(int tag);          //从数组中拿出空闲的飞机·

    _minDuration = 2;

    _maxDuration = 4;

    _enemy1SpawRate = 2.5;

    _enemy2SpawRate = 5;

    _enemy3SpawRate = 100;

    _timeSum1 = 0;

    _timeSum2 = 0;

    _timeSum3 = 0;

void EnemyLayer::initEnemy1()

{

    for (int i = 0; i < ENEMY_MIN_COUNT; i++)

    {

        auto enemy1 = Enemy::create();//创建一个Enemy

        enemy1->bindSprite(Sprite::createWithSpriteFrameName("enemy1.png"), ENEMY_MIN_LIFE);

        this->addChild(enemy1);

        enemy1->setVisible(false);//主要是初始化，还没有要发射，所以不能看到的说~

        enemy1->getSprite()->setTag(ENEMY_MIN);//主要是为了方便后面的函数执行

        _enemyArray1.pushBack(enemy1);//放进数组中

    }

}

Enemy* EnemyLayer::getAvailableEnemy(int tag)

{

    if (tag == ENEMY_MIN)    //就是遍历整个数组，找到一个空闲的（即不可见的）就取出来、·

    {

        for (auto&sp : _enemyArray1)

        {

            if (!sp->isVisible())

            {

                return sp;

            }

        }

        return nullptr;

    }

    else if (tag == ENEMY_MED)       //后面是一样的~

    {

        for (auto&sp : _enemyArray2)

        {

            if (!sp->isVisible())

            {

                return sp;

            }

        }

        return nullptr;

    }

    else

    {

        for (auto&sp : _enemyArray3)

        {

            if (!sp->isVisible())

            {

                return sp;

            }

        }

        return nullptr;

    }

}

void EnemyLayer::spawEnemy1(float dt)//发射灰机~~~~~~~~~~

{

    auto enemy1 = getAvailableEnemy(ENEMY_MIN);//取得一个空闲的灰机~

    if (enemy1)

    {

        enemy1->setLife(ENEMY_MIN_LIFE);          //由于以后可能没打死，但是血扣了，所以每次都要补满血~
        

       //下面这段是计算飞机从哪里出现的~大家可以理解理解~

       Size enemy1Size = enemy1->getSprite()->getContentSize();

        Size visibleSize = Director::getInstance()->getVisibleSize();

        int minX = enemy1Size.width / 2;

        int maxX = visibleSize.width - enemy1Size.width / 2;

        int rangeX = maxX - minX;

        int actualX = (rand() % rangeX) + minX;

        enemy1->setPosition(ccp(actualX, visibleSize.height + enemy1Size.height / 2));

        enemy1->setVisible(true);

       //这个其实主要是一个随机的速度，毕竟飞机不能总是一样快吧~~~~

        int rangeDuration = _maxDuration - _minDuration;

        float actualDuration = CCRANDOM_0_1()*rangeDuration + _minDuration;

        auto actionMove = MoveBy::create(actualDuration, Vec2(0, enemy1->getSprite()->getPositionY() - visibleSize.height - enemy1Size.height));

        auto actionDone = Hide::create();

        auto action = Sequence::createWithTwoActions(actionMove, actionDone);

        //这里的意思就是执行这个动作：从上往下飞过去，如果飞出屏幕就隐藏~。        

        enemy1->runAction(action);

    }

}

void EnemyLayer::spawEnemy(float dt)

{  

   //没错_enemy1SpawRate就是用来控制游戏难度的~当然上面的发射速度也是可以的~，但是我偷懒就用下面这个来了

   //就是计时，每到_enemy1SpawRate后发射出去·

    _timeSum1 += dt;

    if (_timeSum1 >= _enemy1SpawRate)

    {

        _timeSum1 = 0;

        this->spawEnemy1(dt);

    }

}

this->initEnemy1();

    this->schedule(schedule_selector(EnemyLayer::spawEnemy), 1.0/60);