[NTG-pdftex] [PATCH v3] pdftex - Add support for encfile and \pdfgentounicode for PK fonts

[Hans Hagen]

On 3/27/2017 11:53 PM, Reinhard Kotucha wrote:
> On 2017-03-27 at 09:59:34 +0200, Pali Rohár wrote:
>
>  > Anyway, is there some script or program which can generate any PGC
>  > files? Quick look at google does not find anything, even not any
>  > specification for that file. I could probably decode it from pdftex
>  > source code...
>
> AFAIK the "PDF Font Containers" are not officially maintained.  They
> were introduced in order to support development of pdfTeX itself but
> never supposed to be used by mortal users.

We added that as an experiment as part of Thanh's thesis work. It 
permitted injection of shapes generated by metapost.

> Instead of using Type3 fonts, you get better results if you create
> Type1 fonts from the Metafont sources.
>
>   http://www.tex.ac.uk/FAQ-textrace.html
>
> textrace first used autotrace, later potrace, in order to create Type1
> outlines from high-resolution bitmaps created by Metafont.  The
> disadvantage is that the final outlines are not always perferct.  I do
> not know how much time Vladimir Volovich spent on manual tweaking when
> he created the CM-Super Type1 fonts.  On the other hand, Tigran
> Aivazian converted Yannis Haralambous' Hebrew fonts using textrace for
> his Bible project in 2006 and the result was excellent.  AFAIK he
> didn't tweak anything manually.
>
> The main problem with textrace is that I don't know whether this
> program is available anymore.  It's not on CTAN, but if it had ever
> been there, I could check my old TeX Collection CDs/DVDs.
>
> Maybe the better choice nowadays is MetaType1.  The Metafont source
> files are processed by MetaPost and converted to PostScript.  The
> PostScript files are then converted to high-quality Type1 fonts by a
> bunch of scripts.  I assume that MetaType1 is quite reliable because
> the Latin Modern fonts were created with MetaType1, presumably without
> manual interaction.  After all, MetaType1 is still maintained.
>
> Type3 fonts can contain arbitrary PostScript code.  They are just
> collections of pictures.  However, the Type3 font format allows to
> assign pictures to characters.  Even if glyphs are made up of lines
> and curves, the quality is quite poor.  Type1 fonts contain so-called
> "hints" which provide additional information used when glyphs are
> fitted to a grid.  The hints make sure that all vertical stems of an
> "m" have the same width, for example.

fwiw: this matters less on modern displays ... i'm not even sure if the 
lm / gyre have much hinting in them

> dvips (and later pdftex) used the Type3 font format in order to allow
> bitmaps created with Metafont to be inserted into PostScript or PDF
> files.  This was fine at a time when very few Type1 fonts were
> available.
>
> But nowadays I don't see any reason to care about Type3 fonts or "PDF
> Glyph Containers" at all.  The best solution is to create Type1 fonts
> from Metafont sources.

it's still interesting to be able to inject arbitrary shapes (with a bit 
of packaging in actualtext one can even get cut/paste right)

> If you are successful, please upload the Type1 fonts to CTAN.

Hans

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