Objective-C Astronomy Library

Question

I need to do some moonrise azimuth and time calculations. Can anyone recommend a good astronomy library, preferably in Objective-C?

Answer 1

On top of Andrew Hammond answer, I just use Xcode to download the AA. I then remove all the Test files (AATest.cpp AATest.sin AATest.vcproj) and with a warning by Xcode of "Implicit conversion loss integer precision 'long' to 'int'" in the last line on nYear / 100

CAAEasterDetails CAAEaster::Calculate(long nYear, bool GregorianCalendar)
{
  CAAEasterDetails details;

  if (GregorianCalendar)
  {                      
    int a = nYear % 19;
    int b = nYear / 100;

The program compile ok. Only compile if the program is objective c but not if it is Swift based. Got a problem with pre-processor macro AAPLUS_EXT_CLASS.