Kenyth Zeng thinks this is interesting: One of the most interesting applications of contentsRect is that it enables the use of so-called image sprites. From 2. The Backing Image from iOS Core Animation: Advanced Techniques by Nick Lockwood Publisher: Addison-Wesley Professional Released: August 2013 Note css sprite Share this highlight http://www.safaribooksonline.com/a/ios-core-animation/820316/ Twitter Facebook Google Plus Email Get Instant Access Now Start a Free Trial Learn about Safari for Business Have an account? Sign in. Minimise Unlock the rest of iOS Core Animation: Advanced Techniques and 30,000 other books and videos By clicking this box, you confirm that you have read and agree to the terms and conditions of our Membership Agreement, and you understand that when your trial period ends, you will be required to provide billing information if you wish to continue using the service. Unlock the rest of this book Start a Free 10-Day Trial loading Learn about Safari for Business Have an account? Sign in.