Question

Graphics development for iPhone4 and old iPhones was changed in several ways:

1. The concept of point was introduced
   to replace pixel.
2. Methods of UIImage will load high
   resolution resource files with @2x
   in the file name.
3. Scale factor was added to UIScreen,
   UIView, UIImage, and CALayer
   classes.

So if we handle CGImage carefully, it’s not hard to support the high resolution Retina display of iPhone4.

I have several questions about non-native iPad app in iPad 2x mode:

1. Could all the changes from old
   iPhone to iPhone4 (@2x resources
   auto loading, point concept, scale
   factor) be applied to iPad 2x mode.

2. The scale of app on iPad can be
   changed. How can I handle it?

Answer 1

Unfortunately, all of those content scale functions were added in 4.0, so I don’t think there’s any way to use the iOS4 stuff that you’re asking for.