Re: [ft] CFF glyph height doubles with autohinting

[Derek B. Noonburg]

I wonder if it got damaged in email.  I didn't have any trouble opening
it with ftview.  I put a copy up on my web site - maybe that will work
better:

http://www.glyphandcog.com/tmp/t1.cff

The font was embedded in a PDF file I received from a customer.  They
reported a problem viewing the PDF in Xpdf (glyphs too large), and I was
able to track it down to the FreeType autohinter.  I unfortunately don't
have any other versions of the font, or even any info on where the font
came from.

- Derek


On 2014 Jan 23, Eben Sorkin wrote:
> I cannot open this file. 
> 
> Do you have a TTF or OTF perhaps one that has and has not not been hinted yet?
> 
> -e.
> 
> On Jan 23, 2014, at 8:08 PM, Derek B. Noonburg <address@hidden> wrote:
> 
>> I'm seeing an odd case where glyph height in a CFF font doubles with
>> autohinting (relative to using the Adobe engine).
>> 
>> I'm attaching the font in question.  It's a subset that was embedded in
>> a PDF file -- the glyphs are various math symbols.
>> 
>> If I run "ftview 16 f1.cff", and then toggle autohinting on with the 'f'
>> key, the glyphs get taller.  Actually it doesn't seem to be 2x -- closer
>> to 1.5x taller.
>> 
>> I believe the shorter height is correct.  I.e., the Adobe CFF engine is
>> getting it right, and the autohinter is getting it wrong.
>> 
>> I have no idea where this font came from -- I received the PDF file from
>> a customer, and there's no useful info on how it was generated.  So it's
>> also possible that the font is broken.  But I'm not sure how a broken
>> font could trick the autohinter into increasing the height by that much.
>> 
>> I'm using FreeType 2.5.2.
>> 
>> Thanks for taking a look at this.
>> 
>> - Derek
>> <f1.cff>_______________________________________________
>> Freetype mailing list
>> address@hidden
>> https://lists.nongnu.org/mailman/listinfo/freetype
>