cocos2d 粒子系统

    CCSize size=CCDirector::sharedDirector()->getWinSize(); 
    CCParticleSystem* particle=CCParticleSnow::create();
    particle->setPosition(size.width/2,size.height);
    addChild(particle);
    //如果没有最后一句话，那么将会设置
    particle->setTexture(CCTextureCache::sharedTextureCache()->addImage("snow.png"));
    particle->setSpeed(50);