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<p>Thanks, Behdad. Peter also explained this in the MS typography
issue.</p>
<p>Will investigate possible tooling limitations.<br>
</p>
<p>JH<br>
</p>
<p><br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 2023-10-16 12:00 pm, Behdad Esfahbod
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAF63+7VdAQeDwRaw8k1darW4mK8VqxD9JtYj2q8BZ5JP_iV_Bw@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">Hi John,
<div><br>
</div>
<div>What you want is fully doable already. I wrote about it in
the older OpenType list one.</div>
<div><br>
</div>
<div>The point is that the different language systems can point
to different Feature table for the same tag. And it's the
Feature table that carries the extra metadata (name-table
entry etc).</div>
<div><br>
</div>
<div>Hope that helps,</div>
<div><br>
</div>
<div>behdad<br clear="all">
<div>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">behdad<br>
<a href="http://behdad.org/" target="_blank"
moz-do-not-send="true" class="moz-txt-link-freetext">http://behdad.org/</a></div>
</div>
<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sun, Oct 15, 2023 at
10:07 AM John Hudson <<a href="mailto:john@tiro.ca"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">john@tiro.ca</a>> wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">I
posted this query on the MS typography-issues board back in
March, but <br>
received no replies.<br>
<a
href="https://github.com/MicrosoftDocs/typography-issues/issues/1015"
rel="noreferrer" target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://github.com/MicrosoftDocs/typography-issues/issues/1015</a><br>
<br>
My understanding from reading the specification for GSUB
feature <br>
parameters for Stylistic Sets and Character Variant features
is that a <br>
single feature parameter can be applied to a feature tag,
regardless of <br>
how that tag is used in terms of lookup contents for different
script or <br>
language system tags. Is that understanding correct?<br>
<br>
This seems to me to be contrary to the overall OTL model of
script and <br>
langsys structures that are specifically designed to enable
different <br>
writing systems to have different layout behaviours. So, for
example, <br>
when making a font supporting Latin, Cyrillic and Greek
script, it is <br>
perfectly feasible for a stylistic set feature such as ss01 to
have <br>
entirely different behaviour appropriate to each script, and
given the <br>
limited number of 20 registered stylistic set features this is
a more <br>
efficient use of the features; also, it is more intuitive for
the user <br>
of a particular script for accessible stylistic sets in the UI
to begin <br>
as ss01, ss02, etc. rather than these be reserved to some
other, unused <br>
writing system.<br>
<br>
There are also cases where behaviour of stylistic set features
might <br>
differ within a script, at the langsys level. I am currently
looking at <br>
implementing a stylistic set within the Latin script that is
specific to <br>
traditional Irish orthography (langsys IRT). Since it is the
only <br>
stylistic set that would be meaningful within that langsys, my
<br>
inclination would be to use ss01, but that feature has
different <br>
behaviour for other Latin script languages, and different
behaviour <br>
again for other scripts.<br>
<br>
Can anyone see a route out of this, in terms of being able to
link <br>
feature parameters to specific script/langsys combinations?<br>
<br>
JH<br>
<br>
<br>
-- <br>
<br>
John Hudson<br>
Tiro Typeworks Ltd <a href="http://www.tiro.com"
rel="noreferrer" target="_blank" moz-do-not-send="true">www.tiro.com</a><br>
<br>
Tiro Typeworks is physically located on islands<br>
in the Salish Sea, on the traditional territory<br>
of the Snuneymuxw and Penelakut First Nations.<br>
<br>
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</blockquote>
</div>
</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>
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