<div dir="auto">I'm feeling like this is a bit like hinting about 10 years ago...<div dir="auto"><br></div><div dir="auto">For the most important fonts - well established names, premium retail tier work, system fonts - then investment into making them work absolutely everywhere should be possible. Back then this meant hand hinting for several different windows APIs. </div><div dir="auto"><br></div><div dir="auto">But for new fonts with zero million users, ttfautohint or similar was fine, because they worked well enough on the newer APIs used by a majority of users, and the minority of users on older APIs was in terminal decline. </div><div dir="auto"><br></div><div dir="auto">So, existing fonts with indic1/2 tags, that wouldn't work in a hypothetical system that only supports USE and indic 3 tags, seems like it will be small too - and can be resolved by the system shipping harfbuzz for such cases, or the fonts being remastered with all indic 1, 2 and 3 tagged lookups? </div><div dir="auto"><br></div><div dir="auto">The number of indic fonts created in the next 25 years is... Not in terminal decline :) I don't want to say how many multiples than the last 25 years... But anything we do to make it easier for the next generation of type designers around the world is, I think, impactful work. </div><br><div class="gmail_quote" dir="auto"><div dir="ltr" class="gmail_attr">On Fri, Aug 21, 2020, 11:35 PM Peter Constable <<a href="mailto:pgcon6@msn.com">pgcon6@msn.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal">The risk to existing working Indic fonts would be if software supported USE using Indic 3 tags but NOT using legacy Indic engines using Indic 2 tags. When we first created Indic 2 in Windows Vista, we continued to support the original Indic
tags with the original behaviour intact. Back then, there weren’t that many Indic fonts to worry about.<u></u><u></u></p>
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<p class="MsoNormal">Peter<u></u><u></u></p>
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<p class="MsoNormal"><b>From:</b> Dave Crossland <<a href="mailto:dcrossland@google.com" target="_blank" rel="noreferrer">dcrossland@google.com</a>> <br>
<b>Sent:</b> Friday, August 21, 2020 8:21 PM<br>
<b>To:</b> Renzhi Li <<a href="mailto:Renzhi.Li@microsoft.com" target="_blank" rel="noreferrer">Renzhi.Li@microsoft.com</a>><br>
<b>Cc:</b> Andrew Glass <<a href="mailto:Andrew.Glass@microsoft.com" target="_blank" rel="noreferrer">Andrew.Glass@microsoft.com</a>>; Peter Constable <<a href="mailto:pgcon6@msn.com" target="_blank" rel="noreferrer">pgcon6@msn.com</a>>; John Hudson <<a href="mailto:john@tiro.ca" target="_blank" rel="noreferrer">john@tiro.ca</a>>; <a href="mailto:mpeg-otspec@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec@lists.aau.at</a><br>
<b>Subject:</b> Re: [MPEG-OTSPEC] <span style="font-family:"MS Gothic"">回复</span>:
<span style="font-family:"MS Gothic"">回复</span>: [EXTERNAL] Re: Shaping behavior standardization: multi-engine or "Super USE"?<u></u><u></u></p>
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<p class="MsoNormal">On Fri, Aug 21, 2020, 4:55 PM Andrew Glass <<a href="mailto:Andrew.Glass@microsoft.com" target="_blank" rel="noreferrer">Andrew.Glass@microsoft.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">I agree with John, existing engines need to be maintained so long as existing fonts would not be 100% compatible if shaped via USE. That is certainly the case for Indic 1 & 2 tags, hence the goal of supporting Indic 3 via USE. <u></u><u></u></p>
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<p class="MsoNormal">I'm confused - it seems from a discussion on another thread (below) that "indic 3" was an idea floated a a few years ago, but it's been at a dead stop for a while... Is that right?<u></u><u></u></p>
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<p class="MsoNormal">I'm guessing because of the regression risk to existing working fonts?<u></u><u></u></p>
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<p class="MsoNormal">It seems to me that a backwards incompatible format will then be needed, as Li Renzhi says.<u></u><u></u></p>
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<p class="MsoNormal">On Fri, Aug 21, 2020, 8:01 PM Renzhi Li <<a href="mailto:Renzhi.Li@microsoft.com" target="_blank" rel="noreferrer">Renzhi.Li@microsoft.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Enabling cross-script shaping may introduce an API break, and if we need that, it should be done in the OT2 story.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Other possible API-beraking chagnes include:<u></u><u></u></span></p>
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<span style="font-size:12.0pt">32-bit GID<u></u><u></u></span></li></ul>
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<span style="font-size:12.0pt">Breaks DW and CoreText, which defined GID explicitly to UInt16.<u></u><u></u></span></li></ul>
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<p class="MsoNormal">This would be very helpful for the Noto project, where I'd like to see a single Noto Sans that has everything in it. <u></u><u></u></p>
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<span style="font-size:12.0pt">GSUB-GPOS-tangled shaping (i.e., placement-dependent substitution)<u></u><u></u></span></li></ul>
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<span style="font-size:12.0pt">Breaks DW as it perform GSUB and GPOS in <i>different API calls</i>.<u></u><u></u></span></li><li class="MsoNormal" style="color:black">
<span style="font-size:12.0pt">HB is not influenced; not sure about CT.<u></u><u></u></span></li></ul>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Yours,<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Renzhi<u></u><u></u></span></p>
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<p class="MsoNormal"><b><span style="font-family:"Microsoft JhengHei",sans-serif;color:black">发件人</span><span style="color:black">:</span></b><span style="color:black"> mpeg-otspec <<a href="mailto:mpeg-otspec-bounces@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec-bounces@lists.aau.at</a>>
</span><span style="font-family:"MS Gothic";color:black">代表</span><span style="color:black"> Andrew Glass <<a href="mailto:Andrew.Glass@microsoft.com" target="_blank" rel="noreferrer">Andrew.Glass@microsoft.com</a>><br>
</span><b><span style="font-family:"Microsoft JhengHei",sans-serif;color:black">发送时间</span><span style="color:black">:</span></b><span style="color:black"> 2020</span><span style="font-family:"MS Gothic";color:black">年</span><span style="color:black">8</span><span style="font-family:"MS Gothic";color:black">月</span><span style="color:black">21</span><span style="font-family:"MS Gothic";color:black">日</span><span style="color:black">
16:47<br>
</span><b><span style="font-family:"MS Gothic";color:black">收件人</span><span style="color:black">:</span></b><span style="color:black"> Peter Constable <<a href="mailto:pgcon6@msn.com" target="_blank" rel="noreferrer">pgcon6@msn.com</a>>; John Hudson <<a href="mailto:john@tiro.ca" target="_blank" rel="noreferrer">john@tiro.ca</a>>;
<a href="mailto:mpeg-otspec@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec@lists.aau.at</a> <<a href="mailto:mpeg-otspec@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec@lists.aau.at</a>><br>
</span><b><span style="font-family:"MS Gothic";color:black">主</span></b><b><span style="font-family:"Microsoft JhengHei",sans-serif;color:black">题</span><span style="color:black">:</span></b><span style="color:black"> Re: [MPEG-OTSPEC]
</span><span style="font-family:"MS Gothic";color:black">回复</span><span style="color:black">: [EXTERNAL] Re: Shaping behavior standardization: multi-engine or "Super USE"?</span>
<u></u><u></u></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Cross-script shaping support and the abilty to apply locl features to specific glyphs based on BCP-47 tags sounds ideal to me.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Andrew<u></u><u></u></span></p>
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<p>Sent from <a href="https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Faka.ms%2Fweboutlook&data=02%7C01%7C%7Cb7e16c8c866444adfc6708d8464a6d9e%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637336632764057984&sdata=jcdRnpuhAplO%2FBwADiRfUBtLFioiacyr2eRT79W2q6s%3D&reserved=0" target="_blank" rel="noreferrer">
Outlook</a><u></u><u></u></p>
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<p class="MsoNormal"><b><span style="color:black">From:</span></b><span style="color:black"> mpeg-otspec <<a href="mailto:mpeg-otspec-bounces@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec-bounces@lists.aau.at</a>> on behalf of Peter Constable <<a href="mailto:pgcon6@msn.com" target="_blank" rel="noreferrer">pgcon6@msn.com</a>><br>
<b>Sent:</b> Friday, August 21, 2020 4:32 PM<br>
<b>To:</b> John Hudson <<a href="mailto:john@tiro.ca" target="_blank" rel="noreferrer">john@tiro.ca</a>>;
<a href="mailto:mpeg-otspec@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec@lists.aau.at</a> <<a href="mailto:mpeg-otspec@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec@lists.aau.at</a>><br>
<b>Subject:</b> Re: [MPEG-OTSPEC] </span><span style="font-family:"MS Gothic";color:black">回复</span><span style="color:black">: [EXTERNAL] Re: Shaping behavior standardization: multi-engine or "Super USE"?</span>
<u></u><u></u></p>
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<p>Well, that certainly seems like a reason why language systems and features need to remain organized by scripts.
<u></u><u></u></p>
<p> <u></u><u></u></p>
<p>Now, in some OT2.0 future, maybe new formats could be created in which language systems don’t use OT tags at all but use BCP-47 tags directly. Then that would address that issue. And if ‘loc’ features were organized that way but other features don’t need
to be shoe-horned into that structure, we could still have features applied script boundaries triggering lookups that can act on glyphs of whatever scripts.<u></u><u></u></p>
<p> <u></u><u></u></p>
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<p>Peter<u></u><u></u></p>
<p> <u></u><u></u></p>
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<p><b>From:</b> mpeg-otspec <<a href="mailto:mpeg-otspec-bounces@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec-bounces@lists.aau.at</a>>
<b>On Behalf Of </b>John Hudson<br>
<b>Sent:</b> Friday, August 21, 2020 3:09 PM<br>
<b>To:</b> <a href="mailto:mpeg-otspec@lists.aau.at" target="_blank" rel="noreferrer">mpeg-otspec@lists.aau.at</a><br>
<b>Subject:</b> Re: [MPEG-OTSPEC] <span style="font-family:"MS Gothic"">回复</span>: [EXTERNAL] Re: Shaping behavior standardization: multi-engine or "Super USE"?<u></u><u></u></p>
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<p> <u></u><u></u></p>
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<p>On 21082020 1:52 pm, Peter Constable wrote:<u></u><u></u></p>
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<p>Thirdly, if there is one shaping engine for all scripts, would there be any need at all for LangSys and Feature tables to still be organized hierarchically under different script tags? (That’s another existing obstacle to glyph actions across script-run
boundaries.) IOW, instead of a new _<i>set</i>_ of script tags, would just _<i>one</i>_ new “script” tag suffice?
<u></u><u></u></p>
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<p>That’s where my mind started going today. But I'm not sure all the issues that arise can be resolved in that model.<u></u><u></u></p>
<p>If itemisation and glyph run segmentation is not performed on the basis of script tag, and everything using the new USE tag gets processed as a single run, how do we handle characters with locl substitution forms specific to individual scripts? And if such
characters are Unicode script=common, are we pushing the segmentation down a level rather than removing it?<u></u><u></u></p>
<p>J.<u></u><u></u></p>
<pre>-- <u></u><u></u></pre>
<pre> <u></u><u></u></pre>
<pre>John Hudson<u></u><u></u></pre>
<pre>Tiro Typeworks Ltd <a href="https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.tiro.com%2F&data=02%7C01%7C%7Cb7e16c8c866444adfc6708d8464a6d9e%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637336632764057984&sdata=zo8H8D3VztnqZ3aBksjl8UdF4%2Bu5li5dNrVCnkM4Ymg%3D&reserved=0" target="_blank" rel="noreferrer">www.tiro.com</a><u></u><u></u></pre>
<pre>Salish Sea, BC <a href="mailto:tiro@tiro.com" target="_blank" rel="noreferrer">tiro@tiro.com</a><u></u><u></u></pre>
<pre> <u></u><u></u></pre>
<pre>NOTE: In the interests of productivity, I am currently <u></u><u></u></pre>
<pre>dealing with email on only two days per week, usually <u></u><u></u></pre>
<pre>Monday and Thursday unless this schedule is disrupted <u></u><u></u></pre>
<pre>by travel. If you need to contact me urgently, please <u></u><u></u></pre>
<pre>use some other method of communication. Thank you.<u></u><u></u></pre>
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