cocos2d-x中屏幕移动

{

winSize = Director::getInstance()->getWinSize();

Vec2 origin = Director::getInstance()->getVisibleOrigin();

sp1=Sprite::create("HelloWorld.png");

sp1->setPosition(Vec2(winSize.width/2, winSize.height/2));

this->addChild(sp1);

sp2=Sprite::create("HelloWorld.png");

sp2->setPosition(Vec2( winSize.width/2+sp1->getContentSize().width-4, winSize.height/2));

this->addChild(sp2);

this->scheduleUpdate();

}

void HelloWorld:: update(float f)

{

sp1->setPositionX(sp1->getPositionX()-20);

sp2->setPositionX(sp2->getPositionX()-20);

if (sp1->getPositionX()+sp1->getContentSize().width/2<=0) {

sp1->setPositionX(winSize.width+sp1->getContentSize().width/2-4);

}

if (sp2->getPositionX()+sp2->getContentSize().width/2<=0) {

sp2->setPositionX(winSize.width+sp2->getContentSize().width/2-4);

}

}