Recipe: Transforming Views

Affine transforms enable you to change an object’s geometry by mapping that object from one view coordinate system into another. The iOS SDK fully supports standard affine 2D transforms. With them, you can scale, translate, rotate, and skew your views however your heart desires and your application demands.

Transforms are defined in Core Graphics and consist of calls such as CGAffineTransformMakeRotation and CGAffineTransformScale. These build and modify the 3-by-3 transform matrices. Once these are built, use UIView’s setTransform call to apply 2D affine transformations to UIView objects.