RE: [css3-text] fullwidth punctuation kerning

Okay, so you're suggesting to study more and consider adding more values to the property, did I understand correct? If not, it's probably my English isn't good enough, I'm sorry for that in the case.

Current set of values cover the cases from JIS X4051, JLREQ, and Word. You're right that InDesign is another one we should study further, I'll look into that.

If you have any specific concerns or aware of anything I'm missing, please let me know.


-----Original Message-----
From: John Daggett [mailto:jdaggett@mozilla.com] 
Sent: Wednesday, September 29, 2010 11:10 AM
To: Ishii Koji
Cc: www-style; www-font; Eric Muller
Subject: Re: [css3-text] fullwidth punctuation kerning


Eric Muller wrote:

> The spacing behavior of East Asian text cannot be implemented via the 
> OpenType kern feature, and in practice is not. Consider the first 
> example and the case where the  〔 and  the (  come from different 
> fonts or are at different point size; the 'kern' feature will 
> therefore not necessarily "see" both glyphs. Furthermore, the rules 
> for aki behaviors are really style rules and vary from one 
> place/user/document to another. You can already see in the JLREQ 
> document three different sets of values, and a layout engine like 
> InDesign offers a dozen or so built-in sets of values, and lets the 
> user change them arbitrarily. This implies that nothing can be 
> usefully be built in the fonts.

My initial concern about this feature was that specifying manual kerning would conflict with the kerning data in the font.  But if this isn't a problem in practice, rather than remove this property I think we should simply mark this as requiring more study to determine the right set of properties authors need in this situation, properties that cover both the style choices noted in JLREQ and choices commonly used by Indesign users.

John Daggett

Received on Wednesday, 29 September 2010 02:31:25 UTC