cocos2d-x创建精灵(2)

p>    }  

p>}  

p> 

p>也就是init也是真正需要我们定制的：

p>[cpp]  

p>// on "init" you need to initialize your instance  

p>bool HelloWorld::init()  

p>{  

p>    if (!CCLayerColor::initWithColor( ccc4(255,255,255,255) ))  

p>    {  

p>        return false;  

p>    }  

p>  

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

p>    CCSprite *player = CCSprite::create("Player.png",  

p>        CCRectMake(0,0,27,40));  

p>  

p>    player->setPosition(ccp(player->getContentSize().width/2, winSize.height/2));  

p>  

p>    addChild(player);  

p>  

p>    schedule(schedule_selector(HelloWorld::gameLogic),1.0);  

p>  

p>    return true;  

p>}  

p> 

p>看见没，上面就调用了CCLayerColor的函数了。然后里面创建了一个精灵。当然里面还有不严谨的地方，之后我会指出来。

p>我们看重要的一句逻辑：

p>[cpp]  

p>schedule(schedule_selector(HelloWorld::gameLogic),1.0);  

p>这句的作用 API有说明：Callback interval time in seconds. 0 means tick every frame, 就是每隔一段时间回调一次。当然我们使用这个回调来产生敌人的。

p>依次调用的函数有：

p>void HelloWorld::gameLogic( float dt )

p>{

p>addTarget();

p>}

p>[cpp] 

p>void HelloWorld::addTarget()  

p>{  

p>    CCSprite* target = CCSprite::create("Target.png", CCRectMake(0,0,27,40));  

p>    if (NULL == target)  

p>    {  

p>        CCLOG("Create target failed");  

p>        return;  

p>    }  

p>      

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

p>  

p>    const int minY = target->getContentSize().height/2;  

p>    const int maxY = winSize.height-minY;  

p>    const int rangeY = maxY- minY;  

p>    const int actualY = (rand()%rangeY)+minY;  

p>  

p>    target->setPosition(ccp(winSize.width+target->getContentSize().width/2, actualY));  

p>  

p>    addChild(target);  

p>  

p>    const int minDuration = 2;  

p>    const int maxDuration = 4;  

p>    const int rangeDuration = maxDuration-minDuration;  

p>    const int actualDuration = (rand()%rangeDuration)+minDuration;  

p>  

p>    CCFiniteTimeAction* action = CCMoveTo::create((float)actualDuration, ccp(-target->getContentSize().width/2, actualY));