iphone page curl option

I need page curl option for my ebook reader just like iBooks by Apple. For tha开发者_如何学Pythont i got leaves project.I studied that project but its quite difficult for me learn since am a new bee :-). Can anyone of you please explain that page flipping code.Any help is highly appreciated.

I've spent about 9 days and lots of math for implementing that, however it was more sophisticated then in iBooks. Here is very nice solution, but less interactive then in iBooks. You can play with it link