TTX is quite capable of inferring the lookup type from the type of the
main child element of <Lookup>. This should allow for specifying
different kinds of lookup using literal XML.
These substitutions are not generated from the glyphs table, but are
specified statically. Rather than taking a table and transforming it
into XML with C, we could just put the static XML in a string, which
is much simpler. To avoid excessive simplicity, the string is
generated by a pile of preprocessor macros.
This causes no change to the output OTFs.
These are just emitted after the standard AlternateSets, and because
of how TTX works, they end up overriding the standard ones. This
seems a bit dodgy to me, so I might try to do better later.
I just got an SAA5054 (date code 8510) and the character it has at 5/13
is different from the one in the datasheet. The real one lacks the
pixel in the bottom right corner, so it's more like a Ugrave than a
ugrave. However, it would be weird for a character set to include the
capital but not the lower case, and the corresponding character set in
ETS 300 706: May 1997 (the French option in table 36) is obviously
lower-case. So I think it's semantically lower-case, whatever it looks
like.
As for the thing I was intending to check, yes the accent does join onto
the letter.
This means that users of this stylesheet can use declarations like
"font-variant: styleset(saa5051)" to request a particular stylistic set.
The separated graphics sets, 'ss14' and 'ss16', are not covered by this
because new applications should use the proper Unicode code points for
separated graphics instead.
The old approach was that each stylistic set had a distinct glyph-name
suffix, the same way that small caps or right-to-left mirrored glyphs
did. This meant that when several chips used the same alternative
glyph, there needed to be a separate alias for each chip. This was
slightly awkward for just the SAA5051 and SAA5052, but I'd like to add
coverage for the SN74S262 and SN74S263, and those share some of the
same glyphs as well.
So now those stylistic sets have an explicit list of which variant
glyphs they include, and my plan is that each variant glyph will have
a single canonical name. They'll still have to keep the existing
names for compatibility. Indeed, for now that's what they're using
because that makes checking the output easier.
No change to the resulting font, though the lookups do end up in a
different order in the TTX file.
Every feature must have a scripts list, but "suffix" is only one way
you might select lookups to generate. Putting it at the end makes it
easier to leave it out. Indeed, our existing 'aalt' lookup omits it.
This causes no change to the generated fonts.
ISO C doesn't guarantee that the execution character set is ASCII, or
anything like it. Bedstead tries to require only ISO C, but it used
strcmp() to sort glyph names and so the output depended on the sort
order of characters. Moreover, the code for finding variants of
characters required that '.' have a lower value than any other
character that appeared in glyph names.
To avoid this dependency, we now have a table that assigns values to
each character that can appear in glyph names, and a strcmp-compatible
function that compares two strings after mapping through that table.
This means that our sort order is explicitly specified in the code,
and also provides a convenient place to catch unusual characters in
glyph names.
This change has no effect on the output TTX files (at least on an ASCII
system). All remaining uses of strcmp() are testing solely for
equality.
The corresponding members of struct vec are signed, as are most of the
arguments passed to the functions, so it's silly that the parameters
themselves are unsigned. This takes the number of warnings under
clang -Weverything down from 126 to 30.
This doesn't cause any change to the output TTX files.
[ from email ]
2. Regular unicode characters: a few additions, mostly to fill out
compatibility with Teletext character set ranges that were otherwise
almost-complete (which is basically everything except Arabic at this point)
per this reference page: https://al.zerostem.io/~al/ttcharset/[al.zerostem.io]
Some of the cyrillic additions are a bit dubious, but hopefully close enough
to pass.
Ghostscript 10.03.1 and later disable the "makeimagedevice" operator
when running under -dSAFER. Even --permit-devices='*' isn't enough to
get it back. The release notes say that makeimagedevice has been
removed entirely, but that seems not to be correct.
Instead, pass the destination filename to the bdf.ps program and have it
open the file itself. This avoids capturing Ghostscript's own
diagnostics in the output file.
A technique only slightly spoiled by the fact that nothing flags
obsolete characters yet, so it's actually marking every alias instead.
Still, it puts a nice diagonal bar across the affected characters
telling you to use a different one, which looks nice but may
obliterate the character rather _too_ effectively.
