W3C home > Mailing lists > Public > www-style@w3.org > December 2017

[css-fonts] Proposed Variable font spacing axis and CSS letter-spacing property

From: John Hudson <john@tiro.ca>
Date: Sat, 9 Dec 2017 12:07:58 -0800
To: www-style@w3.org
Message-ID: <64e6339d-dc1f-9b17-e309-8282925ab0bc@tiro.ca>
This is a proposal to register a standard OpenType design variations 
axis to affect glyph spacing:
https://github.com/Microsoft/OpenTypeDesignVariationAxisTags/blob/master/Proposals/Spacing_Axis/ProposalSummary.md

Implementations of this 'spac' axis in a variable font would enable font 
makers to provide superior results in letter-spacing conditions by 
providing proportional interaction between letter-spacing distance and 
kerning (via variable GPOS adjustments in the kerning values along the 
'spac' axis), and by managing the design of joining letters in Arabic, 
Devanagari, etc. and in connecting styles of Latin or other scripts, 
which currently get broken connections when letter-spacing is applied.

I'm interested to hear ideas on how support for variable fonts with a 
'spac' feature might be implemented in CSS. A couple of obvious options 
occur to me:

1. User agents could apply 'spac' axis adjustments by default when the 
letter-spacing property is used to expand or contract spacing in text 
set in a variable font including this axis.

2. The letter-spacing property could have a new value defined to allow 
authors to opt in to using 'spac' axis adjustments when applying 
letter-spacing.

Other possibilities or preferred approaches?

JH


-- 

John Hudson
Tiro Typeworks Ltd    www.tiro.com
Salish Sea, BC        tiro@tiro.com

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.
Received on Saturday, 9 December 2017 20:08:27 UTC

This archive was generated by hypermail 2.4.0 : Friday, 25 March 2022 10:09:09 UTC