改变背景颜色+碰撞检测

1.让类继承CCLayerColor比如

class HelloWorld:public cocos2d::CCLayerColor{

public :

在.cpp文件中

bool HelloWorld::init(){

if(!CCLayerColor::initWithColor(ccc4(255,255,255,255))){

return false;

}

使背景颜色变为白色。

2.ccTouchesEnded(CCSet*pTouches,CCEvent*pEvent){

先取得一个点。

CCTouch*onePoint=(CCTouch*)pTouches->anyObject();             //取得一个点，。强制转换一下

CCPoint location=onePoint->getLocationInview();                //取得UI坐标系下的坐标

CCPoint loc=CCDirector::sharedDirector()->convertToNodeSpace(location);            //OPENGL

3.array删除添加难，遍历容易，

list删除添加容易，遍历难，

但是遍历fps时间就一次，但是增加删除2.0s才一次，所以存放在array中，

4.释放两个数组

HelloWorld::~HelloWorld(){

if(_projs!=NULL){

  _projs->release();           //数组释放

}    

5.关于tag

int  tag=who->getByTag();

if(tag==1){

_projs->removeObject(who);

if(tag==2){

_taget->removeObject(who);

.

6.关于update，如果是碰撞检测的话是调用update方法， 即每一帧都检测

 CCARRAY_FOREACH(_targets, itarget){
         CCSprite* target = (CCSprite*)itarget;
 itarget是CCObject类型，这样转换一下才能得到相应的区域。
 得到怪物的的矩形区域
 CCRect targetZone=CCRectMake( 
     target->getPositionX(),
             target->getPositionY(),
             target->getContentSize().width,
             target->getContentSize().height);
 
     CCARRAY_FOREACH(_projs, iproj){
             CCSprite* proj = (CCSprite*)iproj;
             CCRect projZone = CCRectMake(proj->getPositionX(),
                 proj->getPositionY(),
                 proj->getContentSize().width,
                 proj->getContentSize().height); 进行碰撞检测  if(projZone.intersectsRect(targetZone)){       //不能再遍历的时候删除
 
     CCArray* targetToDelete = new CCArray;
     CCArray* projToDelete = new CCArray; 创建两个删除的array。然后把要消除的对象放入todelect集合中

  projToDelete->addObject(iproj);
                 targetToDelete->addObject(itarget);

然后遍历两个删除数组，当然这一次可以直接从删除数组中removeObject( iproj);然后强制转换，然后removeFromParentAndCleanUp();

 CCARRAY_FOREACH(projToDelete, iproj){
         _projs->removeObject(iproj);
         CCSprite* proj = (CCSprite*)iproj;
         proj->removeFromParentAndCleanup(true);
     }

     CCARRAY_FOREACH(targetToDelete, itarget){
         _targets->removeObject(itarget);
         CCSprite* target = (CCSprite*)itarget;
         target->removeFromParentAndCleanup(true);
     }

最后把两个删除数组释放掉

targetToDelete->release();

projToDelete->release();

7.

 void HelloWorld::update(float delta) // delta = 1.0 / fps
 {
     CCArray* targetToDelete = new CCArray;
     CCArray* projToDelete = new CCArray;
     CCObject* itarget;
     CCObject* iproj;
     CCARRAY_FOREACH(_targets, itarget){
         CCSprite* target = (CCSprite*)itarget;

         CCRect targetZone = CCRectMake(target->getPositionX(),
             target->getPositionY(),
             target->getContentSize().width,
             target->getContentSize().height);

         CCARRAY_FOREACH(_projs, iproj){
             CCSprite* proj = (CCSprite*)iproj;
             CCRect projZone = CCRectMake(proj->getPositionX(),
                 proj->getPositionY(),
                 proj->getContentSize().width,
                 proj->getContentSize().height);

             if (projZone.intersectsRect(targetZone)){
                 projToDelete->addObject(iproj);
                 targetToDelete->addObject(itarget);
             }
         } // end of iterate projectile


     } // end of iterate target

     CCARRAY_FOREACH(projToDelete, iproj){
         _projs->removeObject(iproj);
         CCSprite* proj = (CCSprite*)iproj;
         proj->removeFromParentAndCleanup(true);
     }

     CCARRAY_FOREACH(targetToDelete, itarget){
         _targets->removeObject(itarget);
         CCSprite* target = (CCSprite*)itarget;
         target->removeFromParentAndCleanup(true);
     }

     targetToDelete->release();
     projToDelete->release();}