void MainHomeLayer::updateWaterFall(float dt)

{

    static float offset = 0;

    if(NULL != _waterFall)

    {

        _waterFall->removeFromParentAndCleanup(true);

    }

    CCSprite* background = (CCSprite*)this->getChildByTag(eMainHomeLayer_Background);

    CCSprite * waterFall = CCSprite::create("img/mainHome/waterfall.png");

    CCTexture2DPixelFormat pixelFormat =  waterFall->getTexture()->getPixelFormat();

    if(kTexture2DPixelFormat_RGBA8888 == pixelFormat ||

       kTexture2DPixelFormat_RGB5A1 == pixelFormat ||

       kTexture2DPixelFormat_RGBA4444 == pixelFormat)

    {

        float scaleX = background->getScaleX();

        float scaleY = background->getScaleY();

        ///Render Texture Begin

        CCSize textrueSize = CCSizeMake(waterFall->getContentSize().width  * scaleX,waterFall->getContentSize().height * scaleY);

        CCRenderTexture* renderTexture = CCRenderTexture::create(textrueSize.width, textrueSize.height, kTexture2DPixelFormat_RGBA8888);

        renderTexture->begin();

        ccBlendFunc blendFunc1 = {GL_ONE,GL_ONE_MINUS_SRC_ALPHA};

        waterFall->setBlendFunc(blendFunc1);

        waterFall->setOpacity(30);

        waterFall->setPosition(CCPointMake(textrueSize.width * 0.5, textrueSize.height * 0.5));

        waterFall->setScaleX(scaleX);

        waterFall->setScaleY(scaleY);

        waterFall->visit();

        ccBlendFunc blendFunc = {GL_DST_ALPHA,GL_ONE_MINUS_DST_ALPHA};

        ccTexParams tp = {GL_LINEAR,GL_LINEAR,GL_REPEAT,GL_REPEAT};

        float PIXRIS_PRR_SECOND_WATER  =  (CCRANDOM_0_1() * 20 + 20) * scaleY;

        CCSprite * water = CCSprite::create("img/mainHome/Water02.jpg");

        water->setBlendFunc(blendFunc);

        water->setScaleX(scaleX);

        water->setScaleY(scaleY);

        water->getTexture()->setTexParameters(&tp);

        water->setTextureRect(CCRectMake(0, -offset, water->getContentSize().width, water->getContentSize().height));

        water->setPosition(CCPointMake(textrueSize.width * 0.5, textrueSize.height * 0.5));

        water->visit();

        renderTexture->end();

        ///Render Texture End

        this->setWaterFall(renderTexture->getSprite());

        this->getWaterFall()->removeFromParentAndCleanup(true);

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

        this->getWaterFall()->setPosition(CCPointMake(winSize.width * 0.87, winSize.height * 0.8));

        this->addChild(this->getWaterFall(),100);

        offset += PIXRIS_PRR_SECOND_WATER * dt;

    }

}

原文链接：https://blog.csdn.net/zhenyu5211314/article/details/78357156