Cocos2d-xで画像のダウンロードと保存。保存した画像をCCSpriteで表示する

gistfile1.cpp

// HTTP通信
void ResourceDownloader::startDownload(char const *url) {
    CCHttpRequest *request = new CCHttpRequest();

    request->setUrl(url);
    request->setRequestType(cocos2d::extension::CCHttpRequest::kHttpGet);
    request->setResponseCallback(this, httpresponse_selector(ResourceDownloader::onHttpRequestCompleted));

    CCHttpClient::getInstance()->send(request);
    request->release();
}

// コールバックメソッドの中で受信したファイルを保存する
void ResourceDownloader::onHttpRequestCompleted(CCHttpClient *client, CCHttpResponse *response) {
    if (!response->isSucceed()) {return;}

    std::string filePath = CCFileUtils::sharedFileUtils()->getWritablePath() + "image.png";

    std::vector<char> *buffer = response->getResponseData();
    std::ofstream ofs;
    ofs.open(filePath.c_str(), std::ios::out | std::ios::trunc);
    ofs.write(&(buffer->front()), buffer->size());
    ofs.flush();
    ofs.close();
}

// 保存した画像を使う
void ResourceDownloader::createSprite() {
    std::string filePath = CCFileUtils::sharedFileUtils()->getWritablePath() + "image.png";

    CCSprite sprite = CCSprite::create(filePath);
    sprite->setPosition(ccp(320, 240));

    CCNode *pObject = dynamic_cast<CCNode *>(CCDirector::sharedDirector()->getRunningScene()->getChildren()->objectAtIndex(0));
    pObject->addChild(sprite);
}