One problem we'll have when scaling up our UI is that the images' quality will be decreased. A 256 x 256 pixels sprite scaled up to 512 x 512 will look blurry.

In order to avoid having blurry sprites, we could simply have all our assets in high-definition sizes. On the one hand, they will always look good, even on high-resolution displays. On the other hand, displaying a 1024 x 1024 sprite on a small screen with an effective final size of 128 x 128 will result in a waste of the device's memory.

Hence, it is useful to create, for example, three atlases for different resolution ranges: