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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.
Apparently I didn't know about chained comparisons when I wrote this
code, so I didn't take the opportunity to write '0 <= x < limit'.
Also, removed the wildcard import from tkinter, replacing it with
explicit references to the things needed. There weren't that many of
them, so I think the 'import *' didn't gain much.
Apparently I was incredibly lazy at some point in the past and forgot
to say what the problem was when the paste data couldn't be matched
against the regex.
Previously the editor just expected to find it in your cwd. Now by
default it looks in the same directory as its own script, which means
you can run it from some other directory.
Also, I've provided a command-line option to override the default, in
case you keep the executable somewhere else again.
The previous code organisation had a tiny 'Container' classlet that
held all the mutable variables, just so that all the event handler
functions could reach into it and modify it without having to faff
with 'global'.
But if you're going to make that much of a class, it makes more sense
to go further, and make all those functions _methods_ of the class. So
here's a reorganisation that wraps up the Tk code into a more or less
conventional class structure.
The patch for this commit looks like a total rewrite, but it's not
really: everything is indented further to the right (with a couple of
reflowings of long lines), and a lot of variables have a new 'self.'
on the front, but in other respects the code is substantially
unchanged.
At the time I wrote this editor, it was sensible to try to be Python
2/3 agnostic. P2 is now thoroughly obsolete, so I've removed the P2
affordances. That lets me fix the shebang line to say 'python3', and
chmod the file +x, so that you can run it by its name.
Also, it can be renamed to just 'editor', because now that it's
executable, the fact that it's in Python is nothing but an internal
implementation detail.
Ben is trying to make Bedstead into a Debian package, which involves
clarifying copyright and licences anywhere it's unclear. When I
contributed this editing tool I did it on a very informal basis ('look
at this fun hack!') and didn't make that clear. Time to fix that.
For the most part they're not useful, and they're arguably under the GNU
GPL. I've replaced them with an original prose description of some of
the interesting facts. For everything else, you can go to ZVBI itself.
ZVBI is under LGPL v2, but the NOTES file isn't a library so I need to
licence the excerpt under GPL v2 instead. But actually I think I want
to remove that text, so this is just to legitimise the distribution of
the Git history.
Safari badly misdisplays Bedstead in proportional mode. This is
caused by a bug in WebKit, and I haven't found an acceptable
workaround. Thus, I think the best thing to do is to turn off
proportional spacing on the Web page entirely. I think it looks nice,
but even I'll admit that it's a little too tight, and I know others
prefer the monospaced version.
Also, I can't think of a way that a real chip anything like the
SAA5050 could produce proportionally-spaced text. It's fundamentally
based on getting fed character data at a constant 1 MHz. There's no
way it can ask for a character early because the previous one was
narrow.
It's more compact and works just as well. In fact, I think it might
work better on browsers that support background-image but not
background-size. On such browsers the entire rule will be ignored,
which is what I want. If the background image can't appear at
precisely the correct size, it shouldn't appear at all.
Of course, ideally on a browser that fails to display the background,
the title also wouldn't fade out to the left. I wonder if there's a
sensible way to achieve that.
The "sizes" attribute on the icon <links> wasn't allowed by XHTML 1.0
Strict, so I've removed the DOCTYPE for that. Meanwhile HTML 5
doesn't want you declaring a <meta http-equiv="content-type">
specifying XHTML, so I've removed that as well. So now it's
XML-syntax HTML 5, which seems sensible to me even if other people
don't like XML.
HTML doesn't allow <div> inside <h1>. I found before that using a
<span> caused the background not to work. That seems to be down to CSS2
section 10.6.1, describing inline, non-replaced elements: "The height of
the content area should be based on the font, but this specification
does not specify how."
Happily, we can just define this particular <span> to be a block
element, so that it behaves like a <div> even though it's a <span>.
That works fine, and because we're only using it to get a well-defined
content area it doesn't matter if it's ineffective when the stylesheet
is missing.
The W3C HTML 5 checker objects to my use of "–" and I can't see
any reason why I should use it. The page is unashamedly in UTF-8, so
there's not much benefit to singling out this one character for special
treatment.
The page is still officially in XHTML 1.0 Strict at the moment, but I
might want to change that, which is why I'm paying attention to an
HTML 5 checker.
The code predated the introduction of bold variants, so it was
significantly incorrect. Also it appears that some software uses the
PANOSE classification to distinguish monospaced fonts. After careful
study of the specification, I think all the variants of Bedstead can
be classified as text fonts, so I've removed the code that described
some variants as decorative. Then I did some calculations and a lot
of playing around with GeoGebra to work out which parts of the design
space give which values of Stroke Variation, Letterform, and Midline.
At least Noto Sans and Noto Sans Symbols2 think that EM SPACE should
be the same width as mosaic graphics characters, and I think we could
do with a space that doesn't get changed by 'palt'.
I'm a bit uncertain about this because I currently think these glyphs
shouldn't be in Bedstead at all. They're not based on any real system
or standard, so they don't really have any good reason to be here.
But here they are nonetheless, at least until Bedstead 003.000. So
while I don't really want to encourage their use, I think gratuitously
leaving them difficult to use will just annoy anyone who actually has
a use for them and they thus deserve encodings.
That is, not generating aliases at all, becuase that's simpler and
actually makes the OTF file smaller. Which makes me wonder if all
aliases should be done the same way, leaving FontForge to
automatically factor out common bits.
All the *.sep6 glyphs are now aliases for their proper Unicode 16
names. And the 6-cell mosaic graphics are now in the section for
glyphs from real character generators, because that's what they are.
A character can't both be an alias and have its own bitmap data, so we
may as well overlap them. Wrapping them in a union doesn't require any
changes to the syntax of the glyphs array because C allows for
incomplete bracketing of initialisers. Because the union doesn't have a
name, its members can be accessed as though they're members of the
containing struct, which means that accesses to them don't need to
change.
There is a new flag to mark a glyph as an alias since "alias_of == NULL"
no longer works, and a corresponding change to the ALIAS() macro.
This saves about 20K of bedstead's data segment on a 64-bit system,
which is kind of silly but it's satisfying nonetheless.
FontForge has opinions about what order glyphs in an OpenType font
should appear in, at least some of them being mandated by the OpenType
spec (for instance that .notdef must by glyph 0). When outputting an
OpenType font, FontForge re-orders it in accordance with these opinions.
I expect that this will be a problem if I want to emit a table that
FontForge doesn't understand, since it won't be able to correct the
glyph indexes in that table. Thus I've added code to re-order the
glyphs in Bedstead such that FontForge won't re-order them. This should
mean that bedstead.c can safely use the glyph indexes that it generates
without worrying that FontForge might change them.
I don't think FontForge minds what order unencoded glyphs appear in, but
I've defined them to be in strcmp() order of glyph name so that they're
at least somewhat stable. Before this, they were in the same order as
in the source file.
