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RE: [css3-fonts] Language-specific display and 'locl' feature (was RE: [css3-writing-modes] The original issues of font-dependent glyph orientation

From: Koji Ishii <kojiishi@gluesoft.co.jp>
Date: Mon, 3 Oct 2011 01:53:58 -0400
To: John Daggett <jdaggett@mozilla.com>
CC: Taro Yamamoto <tyamamot@adobe.com>, "www-style@w3.org" <www-style@w3.org>, Jonathan Kew <jonathan@jfkew.plus.com>
Message-ID: <A592E245B36A8949BDB0A302B375FB4E0CF69775A3@MAILR001.mail.lan>
Thank you John and Jonathan.

Which OpenType features are on by default was something I was missing, now I understand where to look at. Thank you a lot!


Regards,
Koji

-----Original Message-----
From: John Daggett [mailto:jdaggett@mozilla.com] 
Sent: Monday, October 03, 2011 9:57 AM
To: Koji Ishii
Cc: Taro Yamamoto; www-style@w3.org; Jonathan Kew
Subject: Re: [css3-fonts] Language-specific display and 'locl' feature (was RE: [css3-writing-modes] The original issues of font-dependent glyph orientation

Koji Ishii wrote:

> Maybe I'm asking the same question again, sorry in that case, but so 
> if a font has 'locl' with appropriate script/language system tables, 
> is it automatically applied when 'lang' attribute is set?

Jonathan actually answered this fairly clearly but maybe it would help if I simply restate what he said:

1. Per CSS3 Fonts, the language of an element is mapped to an OpenType language. [1]

2. Per the OpenType spec, the 'locl' feature is on by default. [2]

3. The language/script mechanism in OpenType allows for language or script specific versions of any feature, so to control the default forms of glyphs a font designer could use a language-specific definition of the 'locl' feature.

Default features are somewhat mushily defined in the OpenType spec but implemenations are generally consistent about the core set of default features, including in this case 'locl'.

Regards,

John

[1] language used to determine OpenType language http://dev.w3.org/csswg/css3-fonts/#language-specific-support


[2] locl feature
http://www.microsoft.com/typography/otspec/features_ko.htm#locl

Received on Monday, 3 October 2011 05:53:28 GMT

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