Optimizing a drawing (with finger touches) application for iPhone SDK

Question

I\'m writing an application that uses your finger to draw simple diagrams. I have it working for the most part but now I\'m trying to optimize its performance. When the user swi

Answer 1

drawRect gets called on the main thread. But you don't have to do this. You can use the main thread to collect UI events and do the drawing on a background thread. The background thread gets notified whenever there are new touches and starts a drawing operation in its own CGBitmapContext. Then you create a CGImage and hand it over to the View: view.layer.contents = drawingImage.

If you need even more performance, consider drawing using OpenGL.