cocos2d-x学习笔记(12)--粒子系统

cocos2d-x学习笔记(12)--粒子系统

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     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，有助于理解这一节的代码；

以上的补充主要想说的事，大家在遇到什么不懂得地方的时候，可以多去官方网站去查查资料，那里才是最佳的学习地点。

 

step1:创建cocos2d-win32 application，并命名为particle;

step2:在HelloWorldScene.h中添加下面几个类：

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；

 

 

 

 

 

 

源代码下载地址： http://download.csdn.net/download/wen294299195/4525823