Re: [Libexif-devel] listing headers

[Torsten C. <tc...@va...>]

>> (I would have expected a simple double printed though)
>
> Well, this is what libexif does: it simply prints 3 doubles because
> there are 3 values.

True ... I meant as a single double.

http://www.flickr.com/geoformats.gne

But anyway

> Hmm, did you read my second mail?

Sorry, thought you meant use - not change or copy.

> Check what exif_entry_initialize does
> for e.g. EXIF_TAG_EXIF_VERSION. You should either
> 1) adapt exif_entry_initialize so that it suports also GPS tags
>  (currently it does not)
> 2) copy-past-adapt the code from exif_entry_initialize to your code:

For now I just want to get the POC working. But I will provide a patch
once it's there.
So for now I went with 2)

    static void set_value(ExifEntry *entry, ExifTag tag, ExifByteOrder
order, double value)
    {
        entry->tag = tag;
        entry->components = 3;
        entry->format = EXIF_FORMAT_RATIONAL;
        entry->size = exif_format_get_size(entry->format) * entry->components;

        entry->data = exif_entry_alloc(entry, entry->size);
        if (!entry->data) return;

        // dd/1,mm/1,ss/1 dd/1,mmmm/100,0/1
        ExifRational value1;
        value1.numerator = 1;
        value1.denominator = 1;
        ExifRational value2;
        value2.numerator = 1;
        value2.denominator = 1;
        ExifRational value3;
        value3.numerator = 1;
        value3.denominator = 1;

        exif_set_rational(entry->data, order, value1);
        exif_set_rational(entry->data+sizeof(ExifRational), order, value2);
        exif_set_rational(entry->data+2*sizeof(ExifRational), order, value3);
    }

Still needs the double -> rationals conversion though. Would be nice
if libexif would support some of that a little better. Especially with
exif_entry_alloc not being available outside.

cheers
--
Torsten