Re: [Caml-list] ANN: CamlPDF 1.7

[John Whitington <john@coherentgraphics.co.uk>]

Hi,

Armaël Guéneau wrote:
>> So 0o019 looks like a floating acute in that encoding, followed by a
>> kern of 486/1000 of a point to shift leftward, followed by an 'e'. So,
>> this is an accented character built by composition of glyphs.
>>
>>> For "efficient", with "ffi" being ligated, I get
>>>
>>> Pdfops_TJ (Pdf.Array [Pdf.String "e\014cient"])
>>
>> In the font in use here, character 0o014 appears to be a single glyph
>> for the ffi ligature.
> Yes, ok. How do you know that? I mean, without knowing the displayed text.
> Is there a way, knowing the glyph code (here, 0o019 or 0o014), to convert
> it to something more "readable"? Like, hum, ['] for the floating acute,
> and [ffi]
> for the ligature.

Sometimes, sometimes not. This is what the Pdftext module does. Modern 
PDFs have a /ToUnicode for each font, which is a special data structure 
mapping bytes or sequences of bytes directly to unicode codepoints or 
sequences of unicode codepoints.

In the absence of this, one can fall back to the other parts of the font 
metadata (or even the font itself) which might give the encoding in use.

> I tried to copy paste the text from the pdf using evince, and the
> floating acute
> is indeed rendered separately, but the ligature is properly converted to
> "ffi".

> I guess the interpretation of the glyph code depends on the font, but I
> don't
> find how to do that with CamlPDF - using glyphnames_of_text just returned
> only "/.notdef"...

So it looks like only the ffi part will be doable. I can't really 
comment more without seeing the PDF and your code...

Thanks,

-- 
John Whitington
Director, Coherent Graphics Ltd
http://www.coherentpdf.com/