基于Cocos2d-x-1.0.1的飞机大战游戏开发实例（中）

接《基于Cocos2d-x-1.0.1的飞机大战游戏开发实例（上）》

三、代码分析

1.界面初始化

 1 bool PlaneWarGame::init()
 2 {
 3     bool bRet = false;
 4     do
 5     {
 6         CC_BREAK_IF(! CCLayer::init());
 7
 8         _size = CCDirector::sharedDirector()->getWinSize();
 9
10         // 设置触摸可用
11         this->setIsTouchEnabled(true);
12         // 从窗口中取消息
13         CCDirector::sharedDirector()->getOpenGLView()->SetWin32KeyLayer( this );
14
15         // 初始化游戏背景
16         CC_BREAK_IF(!initBackground());
17         // 菜单1（暂停/声音/炸弹）
18         CC_BREAK_IF(!initMenu1());
19         // 菜单2（继续/重新开始/返回）
20         CC_BREAK_IF(!initMenu2());
21         // 菜单3（重新开始/返回）
22         CC_BREAK_IF(!initMenu3());
23
24         // 创建玩家飞机
25         _player = new PlaySprite;
26         _player->setPosition(CCPointZero);
27         addChild(_player);
28
29         // 调度器:定时调用自定义的回扫函数
30         this->schedule( schedule_selector(PlaneWarGame::gameLoop));
31         this->schedule( schedule_selector(PlaneWarGame::shoot), 0.1 );
32         this->schedule( schedule_selector(PlaneWarGame::addEnemy), 0.3 );
33         this->schedule( schedule_selector(PlaneWarGame::addProp), 5 );
34
35         // 初始化两个数组
36         _enemys = CCArray::array();
37         _enemys->retain();
38         _bullets = CCArray::array();
39         _bullets->retain();
40
41         // 背景音乐
42         CocosDenshion::SimpleAudioEngine::sharedEngine()->playBackgroundMusic(
43             "planewar/game_music.wav", true);
44
45         bRet = true;
46     } while (0);
47
48     return bRet;
49 }

初始化的工作包括：

设置触摸可用
　　设置可自定义处理消息
初始化游戏背景
　　初始化三个菜单（界面菜单/游戏暂停时的菜单/游戏结束时的菜单）
　　初始化两个CCArray类型的数组，分别用来存储有效的敌机精灵对象和子弹对象
设置需要定时调用函数的调度器
设置背景音乐
添加玩家角色

2.初始化游戏背景

 1 bool PlaneWarGame::initBackground()
 2 {
 3     // 显示分数
 4     _label = CCLabelBMFont::labelWithString("0123456789","planewar/font.fnt");
 5     _label->setPosition(ccp(220,_size.height-20));
 6     _label->setColor(ccc3(0,0,0));
 7     this->addChild(_label, 1);
 8
 9     // 显示炸弹数量
10     CCLabelBMFont* bombcount = CCLabelBMFont::labelWithString("X09","planewar/font.fnt");
11     bombcount->setAnchorPoint(ccp(0,0));
12     bombcount->setPosition(ccp(73,10));
13     bombcount->setColor(ccc3(0,0,0));
14     addChild(bombcount, 10,111);
15
16     // 添加背景
17     CCSprite* bg1 = CCSprite::spriteWithFile("planewar/bg1.png");
18     if (!bg1)return false;
19     bg1->setAnchorPoint(ccp(0,1));
20     bg1->setPosition( ccp(0, _size.height) );
21     this->addChild(bg1, 0, 11);
22
23     bg1->runAction(
24         CCSequence::actions(
25         CCMoveBy::actionWithDuration(10,ccp(0,-720)),
26         CCCallFunc::actionWithTarget(this, callfunc_selector(PlaneWarGame::bg1roll)),NULL));
27
28     CCSprite* bg2 = CCSprite::spriteWithFile("planewar/bg2.png");
29     if (!bg1)return false;
30     bg2->setAnchorPoint(ccp(0,1));
31     bg2->setPosition( ccp(0, _size.height*2) );
32     this->addChild(bg2, 0, 12);
33
34     bg2->runAction(
35         CCSequence::actions(
36         CCMoveBy::actionWithDuration(20,ccp(0,-1440)),
37         CCCallFunc::actionWithTarget(this, callfunc_selector(PlaneWarGame::bg2roll)),NULL));
38     return true;
39 }
40
41 void PlaneWarGame::bg1roll(){
42     //运动出屏幕重设位置，运动
43     CCSprite * bg = (CCSprite *)getChildByTag(11);
44     bg->setPosition(ccp(0,1440));
45     CCAction* seq = CCSequence::actions(
46         CCMoveBy::actionWithDuration(20,ccp(0,-1440)),
47         CCCallFunc::actionWithTarget(this, callfunc_selector(PlaneWarGame::bg1roll)),NULL);
48     bg->runAction(seq);
49 }
50
51 void PlaneWarGame::bg2roll(){
52     //运动出屏幕重设位置，运动
53     CCSprite * bg = (CCSprite *)getChildByTag(12);
54     bg->setPosition(ccp(0,1440));
55     CCAction* seq = CCSequence::actions(
56         CCMoveBy::actionWithDuration(20,ccp(0,-1440)),
57         CCCallFunc::actionWithTarget(this, callfunc_selector(PlaneWarGame::bg2roll)),NULL);
58     bg->runAction(seq);
59 }

初始化游戏背景时，需要注意的是：要做出飞机向上走的视觉效果，就要把背景向下滚动，这里使用两个背景bg1和bg2，大小分别为屏幕大小。初始bg1在屏幕内，bg2在屏幕上方，两个同事向下运动；当bg1刚刚运动到屏幕外，bg2刚好盖住屏幕，bg1挪到屏幕上方向下运动...循环操作，就能做出循环滚动的背景效果了。

3.子弹的处理

 1 // 确定子弹类型
 2 void PlaneWarGame::shoot(float dt)
 3 {
 4     if (_isOver)return;
 5     if(_player==NULL) return;
 6
 7     if(_player->_bulletKind == BK_SINGLE)
 8     {
 9         CCSprite *bullet = CCSprite::spriteWithFile(
10             "planewar/plane.png", CCRectMake(112,2,9,17));
11         addBullet(bullet,_player->getPlayerPt());
12     }else if (_player->_bulletKind == BK_DOUBLE)
13     {
14         CCSprite *bullet = CCSprite::spriteWithFile(
15             "planewar/plane.png", CCRectMake(66,238,8,15));
16         addBullet(bullet,ccp(_player->getPlayerPt().x-20,_player->getPlayerPt().y));
17         CCSprite *bullet1 = CCSprite::spriteWithFile(
18             "planewar/plane.png", CCRectMake(66,238,8,15));
19         addBullet(bullet1,ccp(_player->getPlayerPt().x+20,_player->getPlayerPt().y));
20     }
21 }
22 // 添加子弹
23 void PlaneWarGame::addBullet(CCSprite* bullet, CCPoint pt)
24 {
25     bullet->setPosition(pt);
26     this->addChild(bullet);
27
28     bullet->runAction( CCSequence::actions(
29         CCMoveTo::actionWithDuration(0.5, ccp(pt.x,_size.height+bullet->getContentSize().height/2)),
30         CCCallFuncN::actionWithTarget(this,callfuncN_selector(PlaneWarGame::spriteMoveFinished)),
31         NULL) );
32
33     bullet->setTag(1);
34     _bullets->addObject(bullet);
35 }
36 // 回收
37 void PlaneWarGame::spriteMoveFinished(CCNode* sender)
38 {
39     CCSprite *sprite = (CCSprite *)sender;
40     this->removeChild(sprite, true);
41     if (sprite->getTag()==1)//子弹
42         _bullets->removeObject(sprite);
43 }

吃道具可改变子弹类型。子弹的回收方式：从飞机坐标处出发，运动到屏幕外被回收。道具的处理类似。

4.设置触摸/鼠标点击控制玩家角色的移动

 1 bool PlaneWarGame::ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent)
 2 {
 3     if(_player==NULL) return false;
 4
 5     CCPoint pt = CCDirector::sharedDirector()->convertToGL(
 6         pTouch->locationInView(pTouch->view()));
 7
 8     CCRect rt = _player->getRect();
 9     if (CCRect::CCRectContainsPoint(rt,pt))
10         _player->_isDragEnabled = true;
11     return true;
12 }
13
14 void PlaneWarGame::ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent)
15 {
16     if(_player==NULL) return;
17
18     CCSize size = CCDirector::sharedDirector()->getWinSize();
19     CCPoint pt = CCDirector::sharedDirector()->convertToGL(
20         pTouch->locationInView(pTouch->view()));
21
22     CCRect rt = CCRect(0,0,size.width,size.height);
23
24     if (_player->_isDragEnabled && CCRect::CCRectContainsPoint(rt,pt))
25         _player->setPlayerPt(pt);
26 }
27
28 void PlaneWarGame::ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent)
29 {
30     _player->_isDragEnabled = false;
31 }

这里重写3个虚函数。移动角色的方式：触摸/鼠标按下时，如果点击位置在角色上，将角色可被拖拽状态置为true;触摸/鼠标移动时，根据角色的可被拖拽状态和屏幕范围确定是否移动；触摸/鼠标弹起时，将角色的可被拖拽状态恢复为false。

5.碰撞检测

  1 void PlaneWarGame::updateGame(float dt)
  2 {
  3     CCArray *bulletsToDelete = CCArray::array();
  4     CCObject* it = NULL;
  5     CCObject* jt = NULL;
  6
  7     if(_player==NULL) return;
  8
  9     CCRect playerRect = _player->getRect();
 10     // 己方飞机和敌方飞机的碰撞
 11     CCARRAY_FOREACH(_enemys, jt)
 12     {
 13         EnemySprite *enemy = dynamic_cast<EnemySprite*>(jt);
 14         if (!enemy->isNull() && CCRect::CCRectIntersectsRect(playerRect, enemy->getRect()))
 15         {
 16             _player->die();
 17             gameover(false);
 18             return;
 19         }
 20     }
 21
 22     //////////////////////////////////////////////////////////////////////////
 23         // 道具和角色的碰撞检测
 24     CCSprite* prop = (CCSprite*)getChildByTag(8);//子弹
 25     if (NULL != prop)
 26     {
 27         CCRect propRect = CCRectMake(
 28             prop->getPosition().x - (prop->getContentSize().width/2),
 29             prop->getPosition().y - (prop->getContentSize().height/2),
 30             prop->getContentSize().width,
 31             prop->getContentSize().height);
 32         if (CCRect::CCRectIntersectsRect(playerRect, propRect))
 33         {
 34             _player->_bulletKind = BK_DOUBLE;
 35             removeChild(prop,true);
 36             CocosDenshion::SimpleAudioEngine::sharedEngine()->
 37                 playEffect("planewar/get_double_laser.wav",false);
 38         }
 39     }
 40     CCSprite* prop1 = (CCSprite*)getChildByTag(9);//炸弹
 41     if (NULL != prop1)
 42     {
 43         CCRect prop1Rect = CCRectMake(
 44             prop1->getPosition().x - (prop1->getContentSize().width/2),
 45             prop1->getPosition().y - (prop1->getContentSize().height/2),
 46             prop1->getContentSize().width,
 47             prop1->getContentSize().height);
 48         if (CCRect::CCRectIntersectsRect(playerRect, prop1Rect))
 49         {
 50             _player->_bombCount++;
 51             removeChild(prop1,true);
 52             CocosDenshion::SimpleAudioEngine::sharedEngine()->
 53                 playEffect("planewar/get_bomb.wav",false);
 54         }
 55     }
 56
 57     //////////////////////////////////////////////////////////////////////////
 58         // 子弹和敌机的碰撞检测
 59     CCARRAY_FOREACH(_bullets, it)
 60     for (int i=0; i<_bullets->count(); i++)
 61     {
 62         CCSprite *bullet = dynamic_cast<CCSprite*>(_bullets->objectAtIndex(i));
 63         CCRect bulletRect = CCRectMake(
 64             bullet->getPosition().x - (bullet->getContentSize().width/2),
 65             bullet->getPosition().y - (bullet->getContentSize().height/2),
 66             bullet->getContentSize().width,
 67             bullet->getContentSize().height);
 68
 69         CCArray* enemysToDelete =CCArray::array();
 70
 71         CCARRAY_FOREACH(_enemys, jt)
 72         {
 73             EnemySprite *enemy = dynamic_cast<EnemySprite*>(jt);
 74             if (!enemy->_die && CCRect::CCRectIntersectsRect(bulletRect, enemy->getRect()))
 75             {
 76                 if (enemy->_hp>0)
 77                 {
 78                     enemy->_hp--;
 79                     //bulletsToDelete->addObject(bullet);
 80                     _bullets->removeObject(bullet);
 81                     removeChild(bullet,true);
 82                 }
 83                 else if (enemy->_hp<=0)
 84                 {
 85                     //bulletsToDelete->addObject(bullet);
 86                     _bullets->removeObject(bullet);
 87                     removeChild(bullet,true);
 88                     enemysToDelete->addObject(enemy);
 89                 }
 90             }
 91         }
 92
 93         CCARRAY_FOREACH(enemysToDelete, jt)
 94         {
 95             EnemySprite *enemy = dynamic_cast<EnemySprite*>(jt);
 96             enemy->_die = true;
 97             enemy->die();
 98             _bulletsDestroyed++;
 99         }
100
101         enemysToDelete->release();
102     }
103
104     // 释放已死亡的子弹
105     CCARRAY_FOREACH(bulletsToDelete, it)
106     {
107         CCSprite* projectile = dynamic_cast<CCSprite*>(it);
108         _bullets->removeObject(projectile);
109         this->removeChild(projectile, true);
110     }
111     bulletsToDelete->release();
112 }

碰撞检测使用最简单的矩形检测。

6.玩家角色的添加和操作

  1 void PlaySprite::onEnter()
  2 {
  3     CCNode::onEnter();
  4
  5     CCSize size = CCDirector::sharedDirector()->getWinSize();
  6     _sprite = CCSprite::spriteWithFile("planewar/hero1.png");
  7     _sprite->setContentSize(CCSize(62,68));
  8     _sprite->setPosition( ccp(size.width/2,_sprite->getContentSize().height/2) );
  9     addChild(_sprite,10);
 10
 11     CCAnimation * animation = CCAnimation::animation();
 12     animation->addFrameWithFileName("planewar/hero1.png");
 13     animation->addFrameWithFileName("planewar/hero2.png");
 14     CCAction* action = CCRepeatForever::actionWithAction(
 15         CCAnimate::actionWithDuration(0.1f, animation, false));
 16     action->setTag(11);
 17     _sprite->runAction(action);
 18
 19     // 调度器
 20     schedule( schedule_selector(PlaySprite::move), 0.002 );
 21 }
 22
 23 CCRect PlaySprite::getRect()
 24 {
 25     if (_sprite!=NULL)
 26         return CCRect(
 27         _sprite->getPosition().x - (_sprite->getContentSize().width/2),
 28         _sprite->getPosition().y - (_sprite->getContentSize().height/2),
 29         _sprite->getContentSize().width,
 30         _sprite->getContentSize().height);
 31 }
 32
 33 CCPoint PlaySprite::getPlayerPt()
 34 {
 35     if (_sprite!=NULL)
 36         return _sprite->getPosition();
 37 }
 38
 39 void PlaySprite::setPlayerPt(CCPoint pt)
 40 {
 41     if (_sprite!=NULL)
 42         return _sprite->setPosition(pt);
 43 }
 44
 45 void  PlaySprite::setMoveMode( UINT  message, WPARAM  wParam)
 46 {
 47     if (message == WM_KEYDOWN)
 48     {// 控制飞机移动
 49         if (wParam == VK_UP)
 50             _mode = MM_UP;
 51         else if (wParam == VK_DOWN)
 52             _mode = MM_DOWN;
 53         else if (wParam == VK_LEFT)
 54             _mode = MM_LEFT;
 55         else if (wParam == VK_RIGHT)
 56             _mode = MM_RIGHT;
 57     }else if (message == WM_KEYUP)
 58     {
 59         if (wParam == VK_UP || wParam == VK_DOWN ||wParam == VK_LEFT||wParam == VK_RIGHT)
 60             _mode = MM_NONE;
 61     }
 62 }
 63
 64 void PlaySprite::move(float dt)
 65 {
 66     CCSize winSize = CCDirector::sharedDirector()->getWinSize();
 67
 68     switch(_mode)
 69     {
 70     case MM_NONE:
 71         break;
 72     case MM_UP:
 73         if (getPlayerPt().y<winSize.height)
 74             setPlayerPt(ccp(getPlayerPt().x,getPlayerPt().y+1));
 75         break;
 76     case MM_DOWN:
 77         if (getPlayerPt().y>0)
 78             setPlayerPt(ccp(getPlayerPt().x,getPlayerPt().y-1));
 79         break;
 80     case MM_LEFT:
 81         if (getPlayerPt().x>0)
 82             setPlayerPt(ccp(getPlayerPt().x-1,getPlayerPt().y));
 83         break;
 84     case  MM_RIGHT:
 85         if (getPlayerPt().x<winSize.width)
 86             setPlayerPt(ccp(getPlayerPt().x+1,getPlayerPt().y));
 87         break;
 88     }
 89 }
 90
 91 void PlaySprite::die()
 92 {
 93     if (_sprite==NULL)return;
 94
 95     _sprite->stopActionByTag(11);
 96     CCAnimation * animation = CCAnimation::animation();
 97     animation->addFrameWithFileName("planewar/hero_blowup_n1.png");
 98     animation->addFrameWithFileName("planewar/hero_blowup_n2.png");
 99     animation->addFrameWithFileName("planewar/hero_blowup_n3.png");
100     animation->addFrameWithFileName("planewar/hero_blowup_n4.png");
101     _sprite->runAction(CCSequence::actions(
102         CCAnimate::actionWithDuration(0.1f, animation, false),
103         CCCallFunc::actionWithTarget(this, callfunc_selector(PlaySprite::destroy)),NULL));
104 }
105
106 void PlaySprite::destroy()
107 {
108     if (_sprite==NULL)return;
109
110     removeChild(_sprite,true);
111     _sprite = NULL;
112 }