Re: [ft-devel] [Regression] Font doesn't open with Freetype CVS but works with Freetype 2.2.1

[mpsuzuki]

Hi,

On Sat, 26 May 2007 02:16:54 +0300
> On Saturday 26 May 2007 02:13:52 Werner LEMBERG wrote:
> >
> > Hmm, this font doesn't have a `cmap' table, which is invalid according
> > to the OpenType standard, and the behaviour is defined as
> > `implementation specific' in PDF standard (see section 5.5. in the PDF
> > 1.6 specification).
> 
> I see but lots of real world PDF files have this kind of fonts :-/

I remember, ft-devel list receives several posts per year
saying "I found an embedded font in PDF that FT2 cannot
load, FT2 should load it". It's not always stated which
application or library using FT2 to load embedded TrueType
data from PDF.

In my opinion, embedded font in PDF is NOT self-standing
font file. Even if it's forcibly loaded by ignoring essential
tables, it is no more than jumping the first hurdle.
Without cmap, most character-based API are not usable.
One of the next expected hurdle might be "we want to
convert glyph index to character code, to extract or
search a text in PDF. FT2 should do..." It is impossible.
Such requirement should be supplied by slightly higher
level library which can associate the text object,
embedded font object, CMap object, ToUnicode object.
I think it's far higher than FT2. As a result,
the behaviour of current FT2 is reasonable, I think.

However, if somebody can define the reasonable subset of
FT2 API which is required by most PDF parser, it will be
quite helpful for both of FT2 and PDF-related softwares.
If you have some idea of subsetted API for embedded font,
please let me know.

Regards,
mpsuzuki