[Fontinst] Encoding inconsistency?
Lars.Hellstrom at math.umu.se
Wed Dec 3 18:07:56 CET 2003
At 10.30 +0100 2003-12-03, Ulrich Dirr wrote:
>while experimenting with OpenType fonts I came across some
>inconsistencies in encoding files.
I'm not entirely surprised by this. The fontinst ETX and MTX files have a
long history, and during that time some things have changed.
>I have used cm-super-t1.enc as I did not find a t1.enc (what is the
>canonic t1 encoding file? Cork.enc?).
Good question (implies: I don't know the answer). There is a fair chance
there may not be a canonical ENC file for T1.
>When compared with t1.etx
A better object of comparison would be t1draft.etx in
fontinst/doc/encspecs/. t1.etx just aims to produce useful fonts.
t1draft.etx at least aims to specify the encoding. See also encspecs.tex in
that directory for more info on the matter.
>I have found the following differences
These are explained in ltpunct.mtx.
(I assume these are the wrong way round.)
Cool---a (near) non-TeX-occurrence of this thingie! Usually fonts doesn't
have anything like it and therefore relies on MTX files to construct it.
>/uni2423 /visiblespace % and in cork.enc it's /visualspace
Perhaps mostly a matter of the new vs. the old.
>/Ng /Eng % Adobe Eng;014A
>/Tcedilla /Tcommaaccent % Adobe both Tcedilla;0162
This is an old headache, which also involves Scedilla. When T1 was designed
(and for many years afterwards) it was believed that the comma accent (as
used in e.g. Romanian and Latvian) was the same thing as the cedilla
accent, and thus glyphs was named accordingly. Then it was "discovered"
that they were different, and ever since then things have been confused.
Generally, you can't trust the glyph name to accurately describe the glyph
in this case.
As a side note, I see in the Unicode character charts that U+0163 (latin
small letter t with cedilla) is used for "Semitic transliteration", so
maybe it isn't as completely useless as it has been thought to be.
>/dcroat /dbar % dcroat;0111 in Adobe's glyphlist.txt
New and old. See comments in lsbuild.mtx.
>/ng /eng % Adobe eng;014B
>/tcedilla /tcommaaccent % Adobe both tcedilla;0163
>/Germandbls /SS % not in Adobe's glyph list
Making SS a character in T1 was probably mostly due to a desire to support
\uppercase, but it's a rather pointless character. Last time I looked, it
wasn't even in Unicode.
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