Glyphs with rvrn
substitutions don't respond to letter-spacing changes with variable font in Safari (macOS & iOS)
#307
Labels
Bug submitted to WebKit: https://bugs.webkit.org/show_bug.cgi?id=206898
Description of the problem
In Safari on macOS & iOS, some glyphs keep a fixed advance width even if
letter-spacing
is changed significantly (up or down). This problem does not occur in Chrome or Firefox. This problem is not changed by any combination of variable axis values (e.g. by placing non-registered axes above their min value). Rather, it is present whenever a glyph has been substituted withrvrn
(Required Variation Alternates).Examples:
l
keeps same right margin in Sans & Mono styles (MONO = 0 to 1
)f
,g
,i
,r
have fixed advance width in Mono styles (MONO = 1
)slnt < -7.49 or ital > 0.49
)Screenshots
Issue first noticed in
l.sans
, which is subbed in forMONO = 0
styles:Issue also impacts added tracking, e.g.
letter-spacing: 0.3em
:Also present in
l.mono
andg.mono
, which also have glyph substitution (GSUB) fromrvrn
:Problem in
a.italic
,b.italic
,n.italic
(and other italic GSUBs), but not inc
orz
(which have no italic GSUB):Problem is not in Firefox or Chrome:
To reproduce
Useful short test string:
Useful long test string:
Environment
Other details
Issue spotted in live websites & reproduced at wakamaifondue.com and axis-praxis.org.
Issue is not shown in static fonts, reinforcing the theory that this is a problem related to
rvrn
/GSUB.Also happens in other variable fonts, such as Fraunces (which uses
rvrn
to sub-in alternate versions of glyphs like n, s, m.The text was updated successfully, but these errors were encountered: