在游戏适配的过程中，存在ipad中Retina适配问题，需要添加如下代码

if (getDeviceID()==IPAD_RETINA or getDeviceID()==IPHONE_RETINA) {

pDirector->enableRetinaDisplay(true);

}

int getDeviceID(){

int iphone = 1;

int retina = 1;

// Determine device kind

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {

// iPad

iphone = 0;

} else {

// iPhone

iphone=1;

}

// Determine retina display

if ([UIScreen instancesRespondToSelector:@selector(scale)] && UIScreen.mainScreen.scale > 1.0) {

// Retina

retina = 1;

} else {

// Non-retina

retina = 0;

}

if(iphone){

if(retina) return IPHONE_RETINA;

return IPHONE_LOW;

}else {

if(retina) return IPAD_RETINA;

return IPAD_LOW;

}

}