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<div class="moz-cite-prefix">On 08102020 11:50 am, Behdad Esfahbod
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAF63+7UMK2KNCx5F0WVbTv1OMoag6XUJp+AzWP5OKpVknt4KEg@mail.gmail.com">
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0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<p>Accepting that rasterisation and layout implementation
specs should exist, whether they should exist as <i>part</i>
of OFF is less obvious to me.</p>
</div>
</blockquote>
<div><br>
</div>
<div>How so? OFF files include bytes (CFF/CFF2 hinting data as
well as GSUB/GPOS lookups) without specification of how to be
used to display text using that font. This is akin to an image
format specification without a decoding algorithm specified.</div>
<div><br>
</div>
<div>What is the use of such a file format standard then?</div>
</blockquote>
<p>I've been publicly lamenting the absence of an implementation
specification for OTL for a very long time, as you know. And can
make the case that this should be a standard, not simply a
recommendation, and that as a standard it <i>might</i> belong as
part of OFF. In that case, the issue for me is whether I want to
subject the work of creating that standard to the ISO process with
its annoyances and limitations. So in that case, I can also make
the argument for the OTL implementation spec being independent of
the font file format spec — so we can have a public, editable
draft, for exampe —, and have the two standards reference each
other rather than being rolled into one. But that is just an
argument from process.<br>
</p>
<p>In the case of rasterisation, I think there is actually a
stronger argument to be made for keeping the implementation spec
independent of the font file format spec because, for the reasons
I suggested in my previous message, we don't need to standardise a
single implementation, and might actually benefit from multiple
implementation specs, rather than shoe-horning one of them into
the OFF standard.</p>
<p>My understanding is that Adobe themselves have multiple hint
interpreter implementations—the whole philosophy of the PS/CFF
hinting model is that there <i>can</i> be multiple rasterisers
and these can change over time independently of the font data—, so
even if ‘acceptable to Adobe’ were the criterion for including one
rasterisation spec in OFF, <i>which one?</i><br>
</p>
<p>JH</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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