cocos2dx Windows Phone 10 game graphic quality - visual-studio

Question

I am trying to clone a game for Windows phone. This is not for commerical.
I've created new cocos2dx win10 project with cocos creator. And tried to build and executed on Windows Phone 10 Lumia 935. But when I execute on real device, the graphic quality is lower than the original one. The 2 screenshots were attached.
I've setted screen resoulution to 800 x 480. And all images are not scaled.
This is the image on original game.
And this is the image on my new game.
Why these 2 image quality is different?
The original image is this.
What's the reason? I've read this article, but still not found correct answer.
https://github.com/cocos2d/cocos2d-x/issues/15901
The codes that I've implemented was added.
auto director = Director::getInstance();
auto glview = director->getOpenGLView();
if(!glview) {
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WIN32) || (CC_TARGET_PLATFORM == CC_PLATFORM_MAC) || (CC_TARGET_PLATFORM == CC_PLATFORM_LINUX)
glview = GLViewImpl::createWithRect("RealHillClimb", cocos2d::Rect(0, 0, designResolutionSize.width, designResolutionSize.height));
#else
glview = GLViewImpl::create("RealHillClimb");
#endif
director->setOpenGLView(glview);
}
director->setAnimationInterval(1.0f / 180);
glview->setDesignResolutionSize(1280, 720, ResolutionPolicy::NO_BORDER);
auto frameSize = glview->getFrameSize();
int a = Device::getDPI();
if (frameSize.height > mediumResolutionSize.height)
{
director->setContentScaleFactor(MIN(largeResolutionSize.height/designResolutionSize.height, largeResolutionSize.width/designResolutionSize.width));
}
else if (frameSize.height > smallResolutionSize.height)
{
director->setContentScaleFactor(MIN(mediumResolutionSize.height/designResolutionSize.height, mediumResolutionSize.width/designResolutionSize.width));
}
else
{
director->setContentScaleFactor(MIN(smallResolutionSize.height/designResolutionSize.height, smallResolutionSize.width/designResolutionSize.width));
}
director->setContentScaleFactor(1);
cocos2d::Size dsize = glview->getDesignResolutionSize();
float d = director->getContentScaleFactor();
register_all_packages();
auto scene = SCNSplash::createScene();
director->runWithScene(scene);
return true;