iPhone 3 v 4 v iPad ui. Raster vs vector

I'm the design guy on a new iPhone project and am curious on the eat practices for the up elements in the iPhone 3-4 dev. I know the dpi is different between the two and am curious how best to handle this with the dev guys. Do I need to make 2 of everything or do we need to figure how to make vectors of things like buttons , backgrounds and other images?

Any help , e开发者_如何学编程xamples and links would be awesome. My goal is to do the best for the app with asking for dumb things from the developer

Thanks

Your only option right now is to generate PDF images, then draw them manually with core graphics if you absolutely need vector graphics. Otherwise, you can wait for someone (including myself) to get something written third-party like, or you can just make two of everything.

You need to make 2 files.

Lets say you have an image that is 48x48 called Hello.png

the hires version will be 96x96 called Hello@2x.png

The iPhone will automatically determine which image to use.

Thank you, come again.