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<div class="moz-cite-prefix">On 25032020 12:56 pm, Levantovsky,
Vladimir via mpeg-otspec wrote:<br>
</div>
<blockquote type="cite"
cite="mid:MN2PR06MB54389793C9D17BC6C22E44B3FCCE0@MN2PR06MB5438.namprd06.prod.outlook.com">
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0
level1 lfo2"><span style="color:#1F497D"><span
style="mso-list:Ignore">1.<span style="font:7.0pt
"Times New Roman"">
</span></span></span><!--[endif]--><span
style="color:#1F497D">Lack of font metrics for writing systems
other than Western and CJK<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Additional
discussions are needed, we may need to consult with outside
experts who are familiar with typographic environments of
different languages and writing systems to consider the
additional complexities associated with languages like Thai
[where glyphs are often composed with multiple marks
positioned above and below the base].</span></p>
</blockquote>
<p>There are a couple of components to this:</p>
<p>1) Script- or language-specific versions of common metrics used
for linespacing.</p>
<p>2) Script-specific data points that define internal relationships
(in the way, e.g. cap height, x-height, ascender, and descender
data points define height relationships in European scripts).</p>
<p>There has been a lot of prior discussion in the OTWG on (1), and
the consensus seems to be that this should be done with a new
version of the BASE table, using existing OTL script and language
system tags with sets of vertical metrics for linespacing
corresponding to the OS/2 table Typo metrics.</p>
<p>(2) has been discussed in various places, but as you say
consultation is needed to identify the data points that are useful
for each script (which might not always be obvious: much depends
on how the data points might be used, e.g. in calculating size and
alignment of 'dropcap' initials in CSS).</p>
<p>JH<br>
</p>
<p><br>
</p>
<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>
Salish Sea, BC <a class="moz-txt-link-abbreviated" href="mailto:tiro@tiro.com">tiro@tiro.com</a>
NOTE: In the interests of productivity, I am currently
dealing with email on only two days per week, usually
Monday and Thursday unless this schedule is disrupted
by travel. If you need to contact me urgently, please
use some other method of communication. Thank you.</pre>
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