How can you load a font (TTF) from a file using Core Text?

Prior to OSX 10.6, ATSFontActivateFromFileSpecification/ATSFontActivateFromFileReference were available and could be used to load a font from a file. I can't find anything similar in Core Text.

How does TTF file work?

A TrueType font is a binary file containing a number of tables. There is a directory of tables at the start of the file. The file may contain only one table of each type, and the type is indicated by a case-sensitive four letter tag. Each table and the whole font have checksums.

You can get a CTFontRef from a font file by going via a CGFontRef:

CFURLRef url = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, CFSTR("/path/to/font"), kCFURLPOSIXPathStyle, false);
CGDataProviderRef dataProvider = CGDataProviderCreateWithURL(url);
CGFontRef theCGFont = CGFontCreateWithDataProvider(dataProvider);
CTFontRef theCTFont = CTFontCreateWithGraphicsFont(theCGFont);
CFRelease(theCGFont);
CFRelease(dataProvider);
CFRelease(url);

// do something with the CTFontRef here

CFRelease(theCTFont);