cocos2d-x学习笔记(12)--粒子系统

cocos2d-x学习笔记(12)--粒子系统

这次我们要接触的是粒子系统，其实就是游戏中常说的武器系统。在cocos2d-x中文官方网站上http://cn.cocos2d-x.org/document，我截了下图：

上图就是所有的粒子效果，我们只要掌握其使用方法即可。在讲粒子系统之前，我要补充说明一些东西。

首先是CCSprite的继承关系：

可以看到CCSprite继承了CCNode类，而CCNode中包含addChild成员函数，所以CCSprite同样有addChild成员函数。可能之前一直只用layer和scene调用addChild,给大家造成一个习惯，以为只有CCLayer和CCScene类才有addChild，其实不然。再看看下面的继承关系图就一目了然：

接下来下，补充第二个说明：

例子：sprite->runAction(CCRepeateForever::actionWithAction( (CCActionInterval *)(CCSequence::actions (action1, action2, NULL) ) ));

首先我们看看CCSequence::actions的函数原型：

函数的返回值类型是CCFiniteTimeAction，但是我们看看CCRepeateForever::actionWithaction的函数原型：

函数接受的参数类型是CCActionInterval，有于类型不匹配，要转换，转换的根据看了下图就明白了：

CCActionInterval类继承了CCFiniteTimeAction类，那么上面例子的强制转换就存在合理性了。

最后一点就是在看这一节的笔记前，最好看看上一节的笔记cocos2d-x学习笔记(11)--坐标系class ParticleDemo:public CCLayer{protected:CCParticleSystem* m_emitter;CCSprite* m_background;public:ParticleDemo();~ParticleDemo();virtual std::string title();virtual void onEnter();void backCallback(CCObject* pSender);void restartCallback(CCObject* pSender);void nextCallback(CCObject* pSender);virtual void registerWithTouchDispatcher();virtual bool ccTouchBegan(CCTouch* touch, CCEvent* event);virtual void ccTouchMoved(CCTouch* touch, CCEvent* event);virtual void ccTouchEnded(CCTouch* touch, CCEvent* event);void setEmitterPosition();};/************************************************************************//* firework *//************************************************************************/class FireWork:public ParticleDemo{public:virtual void onEnter();std::string title();};class DemoSun:public ParticleDemo{public:virtual void onEnter();std::string title();};class DemoFlower:public ParticleDemo{public:virtual void onEnter();std::string title();};class DemoExplosion:public ParticleDemo{public:virtual void onEnter();std::string title();};class DemoSnow:public ParticleDemo{public:virtual void onEnter();std::string title();};

step3:在HelloWorldScene.cpp中添加如下全局变量及函数：

static int index = 1;const int MAX_INDEX = 5;CCLayer* runThisTest(int index){switch(index){case 1:return new FireWork();case 2:return new DemoSun();case 3:return new DemoFlower();case 4:return new DemoExplosion();case 5:return new DemoSnow();}return NULL;}

在添加对应类的成员函数

/************************************************************************//* ParticleDemo                                                                     *//************************************************************************/ParticleDemo::ParticleDemo(){m_emitter = NULL;setIsTouchEnabled(true);CCSize size = CCDirector::sharedDirector()->getWinSize();//添加基本按钮CCLabelTTF* pNextLabel  = CCLabelTTF::labelWithString("Next ", "Arial", 30);CCLabelTTF*pBackLabel = CCLabelTTF::labelWithString("Back ", "Arial", 30);CCLabelTTF*pRestartLabel = CCLabelTTF::labelWithString("Restart ", "Arial", 30);CCMenuItemLabel* pNextItem  = CCMenuItemLabel::itemWithLabel(pNextLabel, this, menu_selector(ParticleDemo::nextCallback));CCMenuItemLabel* pBackItem = CCMenuItemLabel::itemWithLabel(pBackLabel, this, menu_selector(ParticleDemo::backCallback));CCMenuItemLabel* pRestartItem = CCMenuItemLabel::itemWithLabel(pRestartLabel, this, menu_selector(ParticleDemo::restartCallback));CCMenu* pNextMenu = CCMenu::menuWithItem(pNextItem);CCMenu* pBackMenu = CCMenu::menuWithItem(pBackItem);CCMenu* pRestartMenu = CCMenu::menuWithItem(pRestartItem);pNextItem->setPosition(ccp(size.width/2 +150, 50));pBackItem->setPosition(ccp(size.width/2 - 150, 50));pRestartItem->setPosition(ccp(size.width/2 , 50));pNextMenu->setPosition(CCPointZero);pBackMenu->setPosition(CCPointZero);pRestartMenu->setPosition(CCPointZero);addChild(pNextMenu,1);addChild(pBackMenu, 1);addChild(pRestartMenu,1);m_background = CCSprite::spriteWithFile("HelloWorld.png");addChild(m_background);m_background->setPosition(ccp(size.width / 2, size.height / 2));CCActionInterval* move = CCMoveBy::actionWithDuration(4, ccp(300, 0));CCActionInterval* move_back = move->reverse();m_background->runAction(CCRepeatForever::actionWithAction((CCActionInterval*)(CCSequence::actions(move, move_back, NULL))));}ParticleDemo::~ParticleDemo(){m_emitter->release();}std::string ParticleDemo::title(){return "no title";}void ParticleDemo::onEnter(){CCLayer::onEnter();CCSize size = CCDirector::sharedDirector()->getWinSize();//添加标题std::string strTitle = title();const char* ptitle = strTitle.c_str();CCLabelTTF* pLabel = CCLabelTTF::labelWithString(ptitle, "Arial", 30);pLabel->setPosition(ccp(size.width/2, size.height-40));addChild(pLabel, 1);}void ParticleDemo::backCallback(CCObject* pSender){if(index == 1)return ;index--;CCScene* scene = new CCScene();scene->addChild(runThisTest(index));CCDirector::sharedDirector()->replaceScene(scene);scene->release();}void ParticleDemo::restartCallback(CCObject* pSender){CCScene* scene = new CCScene();scene->addChild(runThisTest(index));CCDirector::sharedDirector()->replaceScene(scene);scene->release();}void ParticleDemo::nextCallback(CCObject* pSender){if(index == MAX_INDEX)return ;index++;CCScene* scene = new CCScene();scene->addChild(runThisTest(index));CCDirector::sharedDirector()->replaceScene(scene);scene->release();}void ParticleDemo::registerWithTouchDispatcher(){ CCTouchDispatcher::sharedDispatcher()->addTargetedDelegate(this, 0, false);}void ParticleDemo::ccTouchEnded(CCTouch* touch, CCEvent* event){CCPoint location = touch->locationInView(touch->view());CCPoint convertedLocation = CCDirector::sharedDirector()->convertToGL(location); CCPoint pos = CCPointZero; pos = m_background->convertToWorldSpace(CCPointZero);m_emitter->setPosition(ccpSub(convertedLocation, pos) );}void ParticleDemo::ccTouchMoved(CCTouch* touch, CCEvent* event){ccTouchEnded(touch, event);}bool ParticleDemo::ccTouchBegan(CCTouch* touch, CCEvent* event){return true;}void ParticleDemo::setEmitterPosition(){CCSize s = CCDirector::sharedDirector()->getWinSize();m_emitter->setPosition( CCPointMake(s.width / 2, s.height / 2) );}/************************************************************************//* firework                                                                     *//************************************************************************/void FireWork::onEnter(){ParticleDemo::onEnter();//添加标题CCSize size = CCDirector::sharedDirector()->getWinSize();std::string strTitle = title();const char* ptitle = strTitle.c_str();CCLabelTTF* pLabel = CCLabelTTF::labelWithString(ptitle, "Arial", 30);pLabel->setPosition(ccp(size.width/2, size.height-40));addChild(pLabel, 1);m_emitter = CCParticleFireworks::node();m_emitter->retain();m_background->addChild(m_emitter, 10);m_emitter->setTexture(CCTextureCache::sharedTextureCache()->addImage("stars.png"));setEmitterPosition();}std::string FireWork::title(){return "firework";}/************************************************************************//* DemoSun                                                                                     *//************************************************************************/void DemoSun::onEnter(){ParticleDemo::onEnter();//添加标题CCSize size = CCDirector::sharedDirector()->getWinSize();std::string strTitle = title();const char* ptitle = strTitle.c_str();CCLabelTTF* pLabel = CCLabelTTF::labelWithString(ptitle, "Arial", 30);pLabel->setPosition(ccp(size.width/2, size.height-40));addChild(pLabel, 1);m_emitter = CCParticleSun::node();m_emitter->retain();m_background->addChild(m_emitter, 10);m_emitter->setTexture(CCTextureCache::sharedTextureCache()->addImage("fire.png"));setEmitterPosition();}std::string DemoSun::title(){return "particle sun";}void DemoFlower::onEnter(){ParticleDemo::onEnter();m_emitter = CCParticleFlower::node();m_emitter->retain();m_background->addChild(m_emitter, 10);m_emitter->setTexture( CCTextureCache::sharedTextureCache()->addImage("fire.png") );setEmitterPosition();}std::string DemoFlower::title(){return "ParticleFlower";}//------------------------------//// DemoExplosion////------------------------------void DemoExplosion::onEnter(){ParticleDemo::onEnter();m_emitter = CCParticleExplosion::node();m_emitter->retain();m_background->addChild(m_emitter, 10);m_emitter->setTexture( CCTextureCache::sharedTextureCache()->addImage("fire.png") );m_emitter->setIsAutoRemoveOnFinish(true);setEmitterPosition();}std::string DemoExplosion::title(){return "ParticleExplosion";}//------------------------------//// DemoSnow////------------------------------void DemoSnow::onEnter(){ParticleDemo::onEnter();CCSize size = CCDirector::sharedDirector()->getWinSize();m_emitter = CCParticleSnow::node();m_emitter->retain();m_background->addChild(m_emitter, 10); // gravity m_emitter->setGravity(CCPointMake(0,-10)); // speed of particles m_emitter->setSpeed(60); m_emitter->setTexture(CCTextureCache::sharedTextureCache()->addImage("fire.png"));m_emitter->setPosition(ccp(size.width / 2, size.height) );}std::string DemoSnow::title(){return "particle snow";}

程序中用的粒子图片大家可以自己自作，不同的图片会显示出不同的效果

step4:编译运行程序，就可以看到粒子效果，我这里只列举了五种效果，还有很多效果没有列举，想要看更多效果，可以自己去官方文档查找；