Re: [ft-devel] CFF divide operator

[Derek B. Noonburg]

On 2016 Feb 05, Werner LEMBERG wrote:
> 
>>> Can you find out which CFF generator created the fonts?  Or are the
>>> fonts even `native' CFF?
>>
>> I'll send you a font file.
> 
> Thanks.
> 
>> The fonts are from a PDF file, which claims:
>>
>> Creator:        Adobe InDesign CS6 (Macintosh)
>> Producer:       DALiM Software Applications
> 
> OK.
> 
>> I'm not quite sure what you mean by 'native CFF'.
> 
> Sorry for being imprecise.  I've meant a CFF not within a SFNT
> wrapper.

Ah, ok.  The fonts in that PDF file are naked CFF fonts, which PDF
refers to as "Type 1C".

>> I don't know if HelveticaNeueLTCom-Md is distributed as Type 1 or
>> OpenType/CFF, so it's hard to say where the subset came from.
> 
> Well, the thing is that it is normally possible to avoid the `div'
> operator completely since non-integer numbers can be directly
> represented in Type 2.  And looking into the font, all charstrings
> look indeed like the following.
> 
>  512 222 3390 29 div  
>  rmoveto
>  1950 29 div
>  vlineto
>  56 hlineto
>  -1950 29 div
>  vlineto
>  -1535 29 div
>  3390 29 div
>  rmoveto
> 
> So I'm really suprised that Adobe's converter didn't catch this.

It's probably not Adobe's fault.  The "Creator" and "Producer" metadata
aren't terribly reliable, but Creator is probably the software that
created the original document, and Producer is probably the software
that produced the PDF file.

I'm not familiar with DALiM, but my guess is that they did some kind of
font conversion (or substitution, or whatever), and that's where the div
operators came from.

It does seem weird to be dividing by 29, though.

- Derek