[XeTeX] Problem with ocrb10.otf ligature 'fi'

[Pander]

On 2011-06-13 14:56, Pander wrote:
> TeX Live list members: see full thread here:
> http://tug.org/pipermail/xetex/2011-June/020681.html for now keep the
> discussion at XeTeX's list.
> 
> On 2011-06-13 14:22, mskala at ansuz.sooke.bc.ca wrote:
>> On Mon, 13 Jun 2011, Pander wrote:
>>> TeX Live 2010
>>>
>>> /usr/local/texlive/2010/texmf-dist/fonts/opentype/public/ocr-b-outline/ocrb10.otf
>>
>> That is Zdeněk Wagner's auto-conversion of Norbert Schwarz's Metafont
>> source.  It doesn't contain f-ligatures no matter what the GSUB table may
>> say.  I took a look at it with Fontforge and I see that it contains a GSUB
>> table pointing the ligatures at "alternate" and added non-ASCII characters
>> from the Schwarz version, some of which happen to be ligature-like but not
>> the correct ones.  For instance, "fl" points at the Æ glyph.
>>
>> I recogize that pattern because it happened in an earlier version of my
>> own version of the font, as a result of auto-conversion.  The thing is,
>> Schwarz's Metafont files used a nonstandard custom encoding.  If you
>> simply convert the font code point for code point to whatever the default
>> 8-bit Adobe encoding might be, you end up with Schwarz's extra glyphs at
>> the "f-ligature" code points (as well as some distortions at quotation
>> mark, dotless i and j, and similar code points).  The existence of a GSUB
>> table pointing at those points can probably be explained by defaults from
>> the auto-conversion.  So in summary, yes, it's a bug in the font.
> 
> Could the conversion software generate a warning when it recognises such
> a situation?
> 
>> The current version of my own OCR B fonts, available on ansuz.sooke.bc.ca,
> 
> http://ansuz.sooke.bc.ca/page/fonts
> 
>> is also based on Schwarz's, but via a more manual conversion process
>> (rewriting the Metafont sources to work with MetaType1), and I've
>> attempted to put all glyphs at their correct Unicode code points.  It
>> contains a GSUB table for alternate forms of glyphs, but none for
>> ligatures.
>>
>>>> I just downloaded the demo from here:
>>>>       http://www.barcodesoft.com/ocr_font.aspx
>>
>>> Maybe TeX Live should use these OTF files?
>>
>> Barcodesoft's "free" version is a watermarked demo of an expensive
>> commercial product, basically just an advertisement, and for that reason I
>> wouldn't recommend its distribution in TeXLive; I'm not even sure that the
>> license agreement would allow such distribution.
> 
> In effect it is freeware and is owned by Barcodesoft. But according to
> your README, one is allowed to redistribute this and your enhanced
> version. So in the same way would TeX Live be able to so. The metadata
> in the font files provides proper credits.
> 
> I think, first CTAN needs to be properly updated, see:
>   http://ctan.org/search/?search=ocr&search_type=description
> Probably many of these CTAN package can merge.
> 
> Subsequently TeX Live can do their update. For now, I'll forward this
> also to them.
> 
> Would it also be possible to generate Bold, Italic, Light and Condensed
> versions for OCR-A and OCR-B? In that way it is also backwards
> compatible with the current OCRA fonts.

And Ubuntu should also switch to these OCRA fonts for ttf-ocr-a? What is
in there is from 2009 and is credited to
"Created by Sauter,U-TOWN_HALL\Sauter,S-1-5-21-2526881554-1349 with
FontForge 1.0 (http://fontforge.sf.net)"

These are the fonts:

OCRALight:style=Light
OCRACondensed:style=Condensed
OCRAItalic:style=Italic
OCRA:style=Medium
OCRABold:style=Bold

With this changelog:

tf-ocr-a (1.0-2) unstable; urgency=low

  * Update my email address.
  * Change section to fonts.
  * Bump debhelper version.
  * Bump standards version.
  * Add Debian Fonts Task Force to Uploaders.
  * debian/copyright: Updated.

 -- Gürkan Sengün <gurkan at phys.ethz.ch>  Wed, 05 Aug 2009 08:53:55 +0200

ttf-ocr-a (1.0-1) unstable; urgency=low

  * Initial release. (Closes: #452980)

 -- Gürkan Sengün <gurkan at linuks.mine.nu>  Wed,  2 May 2007 16:17:15 +0200

It also has an interesting ReadMe.txt file

So perhaps time to consolidate OCR-A and OCR-B in the different
dictributions (TeX Live and Ubuntu) to those new ones?

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