<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>The font wouldn’t need to do anything special in this scenario.
The behaviour you describe is the sort of thing that is usually
found at the application level, which is where text
highlighting/colouring takes place, in concert with the shaping
engine. It seems easy enough to do: check for presence of
variation selector sequences, check for format 14 cmap mappings
for those sequences in the current font, highlight any sequences
without mappings.</p>
<p>[In the context of the runology queries, I don’t think variation
selectors are the best solution. There are similar issues in the
study of historical texts in many writing systems, and the set of
variants is usually too large and too open-ended to be suitable
for Unicode’s strict definition of variation selector forms. The
current version of the Brill Epichoric font, for instance,
includes 31 forms of Alpha—not including RTL boustrophedon
variants and stoichidon spacing forms—and it only takes discovery
and publication of one more inscription to introduce one or more
additional variants.]<br>
</p>
<p>JH<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 2024-06-07 4:11 am, William_J_G
Overington via mpeg-otspec wrote:<br>
</div>
<blockquote type="cite"
cite="mid:5bb4279a.ce63.18ff26522e7.Webtop.126@btinternet.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<p><span style="font-size:18px;">There is a document</span></p>
<p> </p>
<p><span style="font-size:18px;">(R)Unicode: Encoding and
Sustainability Issues in Runology</span></p>
<p> </p>
<p><span style="font-size:18px;"><a class="moz-txt-link-freetext" href="https://www.unicode.org/L2/L2024/24129-runology.pdf">https://www.unicode.org/L2/L2024/24129-runology.pdf</a></span></p>
<p> </p>
<p><span style="font-size:18px;">I have no expertise at all in
Runology but I did notice one thing in the document that has
prompted me to make an observation.</span></p>
<p> </p>
<p><span style="font-size:18px;">On page 14 the document has the
following.</span></p>
<p> </p>
<p><span style="font-size:18px;">> Fonts supporting that form
would display the appropriate glyph, recognising the string of
base-character + variation selector, but fonts without such
support would ignore the variation selector and fall back to a
generic form for the base character.</span></p>
<p> </p>
<p><span style="font-size:18px;">I suggest that it would be
possible to have a version of the program that displays the
glyphs to be such that if the fall back glyph is displayed due
to the requested glyph not being available in the font, then
that fall back glyph could be displayed in, say, red, or some
other way, so that it would be clear that that was the
situation rather than it being just an unreported fallback
situation. Is that possible with fonts and rendering systems
as they are now?</span></p>
<p> </p>
<p><span style="font-size:18px;">So it would not be a situation of
the variation selector request being ignored, but a situation
of the variation selector request not being acted upon yet a
notification that the request had not been acted upon notified
to the researcher.</span></p>
<p> </p>
<p><span style="font-size:18px;">I appreciate that this would not
be a feature requiring encoding in Unicode, but would involve
the font and the rendering system. So how could this be
implemented please, indeed are there any programs that already
implement such a feature? If the font returns the default
glyph when asked for the variation sequence requested glyph,
does the rendering system know that this is the case? If so,
how? If not, can a feature be added to the font specification
so that the rendering system will know please?</span></p>
<p> </p>
<p><span style="font-size:18px;">I am thinking that such a feature
could b useful in various situations, not only runology.</span></p>
<p> </p>
<p><span style="font-size:18px;">William Overington</span></p>
<p><br>
<span style="font-size:18px;">Friday 7 June 2024</span><br>
</p>
<p> </p>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
mpeg-otspec mailing list
<a class="moz-txt-link-abbreviated" href="mailto:mpeg-otspec@lists.aau.at">mpeg-otspec@lists.aau.at</a>
<a class="moz-txt-link-freetext" href="https://lists.aau.at/mailman/listinfo/mpeg-otspec">https://lists.aau.at/mailman/listinfo/mpeg-otspec</a>
</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
John Hudson
Tiro Typeworks Ltd <a class="moz-txt-link-abbreviated" href="http://www.tiro.com">www.tiro.com</a>
Tiro Typeworks is physically located on islands
in the Salish Sea, on the traditional territory
of the Snuneymuxw and Penelakut First Nations.
__________
EMAIL HOUR
In the interests of productivity, I am only dealing
with email towards the end of the day, typically
between 4PM and 5PM. If you need to contact me more
urgently, please use other means.</pre>
</body>
</html>