How to support (iphone, ipod, ipad) all screen size by cocos2dx

Hi,

We want to support all iphone and ipad size 480*320 960*640 1024*768 2048*1536

Now we prepared two types of png files, the one is 960*640 size, the other one is 2048*1536 size

How can we set our project to support all screens?
Thanks

If you are not considering to port your games to android, you should prepare two kinds of coordinates, one for iphone, another for ipad. And enable retina mode.
Or you should get all your relative coordinates from .ccb files which are exported from CocosBuilder.