- From: Richard Ishida <ishida@w3.org>
- Date: Fri, 25 Apr 2014 17:41:55 +0100
- To: W3C Style <www-style@w3.org>, www International <www-international@w3.org>
> On Jan 25, 2014, at 9:07, Peter Moulder <pjrm@mail.internode.on.net> wrote: > >> On Sat, Jan 25, 2014 at 10:30:00AM +1100, I wrote: >> >>> I would thus be careful about specifying that this bar should always >>> have visible gaps when letter-spacing is non-zero. >> >> More practically in terms of how to word the spec when addressing this >> issue (if indeed we don't wish to specify that this bar should always have >> visible gaps): the spec might merely say where letter-spacing is applied >> (namely at syllable boundaries), without necessarily even mentioning the bar. If >> gaps in the bar are mentioned, then the requirement might be on where gaps >> should/must not appear. > > Hm, I agree to leave things that we’re not certain undefined. > > Is the “syllable boundaries” different from the current grapheme cluster > definitions? If no, I suppose there’s no need to update the spec. > > If different, is it possible to change Unicode grapheme cluster, or is > it something that letter-spacing point needs to be different from > grapheme cluster boundaries? I have sent a note to the Indic Layout Task Force list asking for clarification, and will report back what they say. My current understanding is that the units around which letter-spacing applies are different depending on which font is used. If the font indicates consonant clusters without showing the virama, then the unit is the whole consonant cluster plus vowel-signs, diacritics etc. This is very often likely to NOT coincide with extended grapheme clusters. If the font does show the virama explicitly, then the stretching appears just after the virama. I think that this DOES map to grapheme clusters as defined by Unicode. As i said, I'll let you know if the indic experts get back to me to confirm this one way or another. RI
Received on Friday, 25 April 2014 16:42:24 UTC