cocos2dx打飞机项目笔记四：Enemy类和EnemyLayer类

Enemy类没什么内容，就create和init方法，根据参数来创建不同的敌机，头文件代码如下：

 1 //飞机的类型

 2 enum planeType {smallPlane, midPlane, bigPlane};

 3 

 4 class Enemy : public CCSprite

 5 {

 6 

 7 public:

 8 

 9     void loseLife();

10     

11     CC_SYNTHESIZE(float, m_speed, Speed);

12     CC_SYNTHESIZE(int, m_life, Life);

13     CC_SYNTHESIZE(int, m_score, Score);

14     CC_SYNTHESIZE(planeType, m_type, Type);

15 

16     ~Enemy();

17     virtual bool init(planeType type, CCTexture2D* texture);

18     static Enemy* create(planeType type, CCTexture2D* texture);

19 

20 };

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create和init方法实现如下：

Enemy* Enemy::create(planeType type, CCTexture2D* texture)

{

    Enemy *pRet = new Enemy(); 

    if (pRet && pRet->init(type, texture)) 

    { 

        pRet->autorelease(); 

        return pRet; 

    } 

    else 

    { 

        delete pRet; 

        pRet = NULL; 

        return NULL; 

    }

}



bool Enemy::init(planeType type, CCTexture2D* texture)

{

    bool bRet = false;

    do 

    {

        const char* fileName;

        float score = 0;

        int life = 0;

        float speed = 0;



        int random_speed = rand() % 6 + 2;





        switch (type)

        {

        case bigPlane:

            fileName = "enemy3_n1.png";

            life = 15;

            score = 100;

            break;



        case midPlane:

            fileName = "enemy2.png";

            life = 8;

            score = 50;

            break;



        case smallPlane:

            fileName = "enemy1.png";

            life = 1;

            score = 10;

            break;



        default:

            break;

        }

;

        CC_BREAK_IF(!CCSprite::initWithSpriteFrameName(fileName));



        this->m_score = score;

        this->m_life = life;

        this->m_speed = 50*random_speed;

        this->m_type = type;

        bRet = true;



    } while (0);



    return bRet;

}

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EnemyLayer类则负责敌机除了创建之外的所有工作，包括开始启动创建方法、停止创建、移除敌机、敌机爆炸等。头文件：

 1 class EnemyLayer : public cocos2d::CCLayer

 2 {

 3 

 4 protected:

 5 

 6     CCSize designResolutionSize;

 7     CCSpriteBatchNode* batchNode;

 8 

 9 public:

10 

11     CCArray *m_enemys;

12 

13     EnemyLayer(void);

14     ~EnemyLayer(void);

15     virtual bool init();

16     

17     void startTakeEnemys(float dt);

18     void stopTakeEnemy(void);

19 

20     void EnemyMoveToFinish(CCNode* pSender);

21     void removeEnemy(CCNode* pTarget, void* enemy);

22     void removeAllEnmeys();

23 

24     void addEnemy(float dt);

25 

26     void bomb(CCNode* pSender);

27     

28     CREATE_FUNC(EnemyLayer);

29 };

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敌机的创建和子弹不同，还记得子弹的创建我是保证屏幕上只有一粒子弹的吧，敌机则不然，固定每隔多少时间就会创建

1 void EnemyLayer::startTakeEnemys(float dt)

2 {

3     

4     float delay = 1.0f;//多少秒后调用

5     float interval = 0.3f;//调用时间间隔

6     this->schedule(schedule_selector(EnemyLayer::addEnemy), interval, kCCRepeatForever, delay);

7 }

 

addEnemy和bomb方法实现：

 1 void EnemyLayer::addEnemy(float dt)

 2 {

 3     if (true)

 4     {

 5         int seed = 19;

 6         int random_planeType = rand() % seed + 1;//1~19

 7         planeType type;

 8 

 9         Enemy* enemy = NULL;

10 

11         //按概率随机生成大中小三种敌机，或者不产生

12         //big

13         if (random_planeType % 19 == 0)

14         {

15             type = bigPlane;

16             SimpleAudioEngine::sharedEngine()->playEffect("music/big_spaceship_flying.wav",false);

17         } 

18         //mid

19         else if(random_planeType % 5 == 0)

20         {

21             type = midPlane;

22         }

23         //small

24         else if(random_planeType % 2 == 0)

25         {

26             type = smallPlane;

27         }

28         // no

29         else

30         {

31             return;

32         }

33             

34         enemy = Enemy::create(type, this->batchNode->getTexture());

35 

36         

37         //初始位置(随机)

38         CCSize winSize = CCDirector::sharedDirector()->getWinSize();

39         float x = rand() % (int)(winSize.width - (int)enemy->boundingBox().size.width * 2) + enemy->boundingBox().size.width;

40         float y = winSize.height - enemy->boundingBox().size.height/2;

41 

42         CCPoint position = ccp(x,y);

43 

44         enemy->setPosition(position);

45         this->m_enemys->addObject(enemy);

46         batchNode->addChild(enemy);

47 

48         //敌机的运动轨迹CCDirector::sharedDirector()->getWinSize()

49         float length = enemy->getContentSize().height + designResolutionSize.height;//飞行距离，超出屏幕即结束

50         float velocity = 10/1;//飞行速度：420pixel/sec

51         float realMoveDuration = length/enemy->getSpeed();//飞行时间

52 

53         CCFiniteTimeAction* actionMove = CCMoveTo::create(realMoveDuration,ccp(x, -enemy->getContentSize().height));

54         CCFiniteTimeAction* actionDone = CCCallFuncN::create(this,callfuncN_selector(EnemyLayer::EnemyMoveToFinish));//回调一个敌机结束处理函数

55 

56         CCSequence* sequence = CCSequence::create(actionMove,actionDone,NULL);

57 

58         enemy->runAction(sequence);

59 

60     }

61     

62 }

63 

64 

65 void EnemyLayer::bomb(CCNode* pSender)

66 {

67 

68     CCAnimation *animationBomb = NULL;

69     Enemy *enemy = (Enemy*) pSender;

70     char bombMusciName[64];

71 

72     if (enemy->getType() == bigPlane)

73     {

74         sprintf(bombMusciName, "music/enemy3_down.wav");

75         animationBomb = CCAnimationCache::sharedAnimationCache()->animationByName("animation_Enemy3Bomb");

76     } 

77     else if(enemy->getType() == midPlane)

78     {

79         sprintf(bombMusciName, "music/enemy2_down.wav");

80         animationBomb = CCAnimationCache::sharedAnimationCache()->animationByName("animation_Enemy2Bomb");

81     }

82     else if(enemy->getType() == smallPlane)

83     {

84         sprintf(bombMusciName, "music/enemy1_down.wav");

85         animationBomb = CCAnimationCache::sharedAnimationCache()->animationByName("animation_Enemy1Bomb");

86     }

87 

88     SimpleAudioEngine::sharedEngine()->playEffect(bombMusciName, false);//开始播放背景音效，false表示不循环 

89 

90     CCActionInterval *action = CCScaleTo::create(0.5f, pSender->getScale() + 0.05f);

91     CCCallFuncND *funcND = CCCallFuncND::create(this,callfuncND_selector(EnemyLayer::removeEnemy),(void*)pSender);

92     CCFiniteTimeAction* seq = CCSequence::create(CCAnimate::create(animationBomb), funcND, NULL);

93 

94     pSender->stopAllActions();

95     pSender->runAction(seq);

96 

97 }

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可以看得出，这两个方法其实放到Enemy类里也很正常完全没问题的，这个要看coder想怎么写了。另外，敌机飞出屏幕外时的删除和被子弹打中时爆炸的回收是不同，差一个爆炸效果，而子弹在这两种情况的处理是一样的。