about open-type display

[roger64]

Using calibre 7.0. for Linux (downloading slowly 7.1.)

I noted that both the Calibre viewer and editor failed to display this line in the css:

font-variant-numeric: oldstyle-nums;

I can remember that older versions of Calibre, at least since 2020, could display it for some books with embedded fonts. Is it a Qt effect?

[kovidgoyal]

css is displayed by qt webengine, aka chromium. as far as I know chromium supports this property just fine.

[nabsltd]

Originally Posted by roger64

I noted that both the Calibre viewer and editor failed to display this line in the css:

font-variant-numeric: oldstyle-nums;

I noticed you had a post about font subsetting. If you subset the font, it might remove the old style numbers, because subsetting algorithms usually only look at code points used directly. The OpenType transform code probably isn't being run by the subsetting code.

I have found that unless the font has full Unicode support (i.e., more than 10K code points), subsetting doesn't save you enough space to be worth it.

[Quoth]

Originally Posted by nabsltd

I have found that unless the font has full Unicode support (i.e., more than 10K code points), subsetting doesn't save you enough space to be worth it.

Or if the font is only used in some headings.
I agree, pointless for body text unless the font has some Asian non-alphabetic glyphs and you don't use that language.