converting TrueType Macintosh Language Codes to BCP 47 language tags

Question

Truetype fonts use "Macintosh Language Codes" to describe the language of localised strings in the "name" table. A list of language codes can be found in in the TrueType spec. I need to convert these language codes to BCP 47 language tags. Is there a table somewhere which shows the corresponding language tags for each code? Or some pre-existing code which does this translation somewhere? Or maybe a MacOS API which can translate codes to tags for me?

Answer 1

You can use the CFLocaleCreateCanonicalLocaleIdentifierFromScriptManagerCodes to map from legacy IDs to BCP 47 tags.

Edit by the OP: the following code works for me.

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    CFAllocatorRef alloc = CFAllocatorGetDefault();
    for (int i = 0; i <= 150; i++) {
        CFLocaleIdentifier bcp47 = CFLocaleCreateCanonicalLocaleIdentifierFromScriptManagerCodes(alloc, i, -1);
        const char *s = CFStringGetCStringPtr(bcp47, kCFStringEncodingUTF8);
        if (s) {
            printf("%d: \"%s\",\n", i, s);
        }
    }
    return 0;
}