How do I manually specify the fallback fonts for sans-serif, serif, monospace, etc.?

[rtiangha]

Based on hobnail's suggestion to test generic font families in DomesticExtremis's EPUB Feature Peeker thread, for fun, I modified the epub to add a section that outputted text solely using the generic font families of serif, sans-serif, monospace, cursive and fantasy (ex. { font-family: sans-serif } ) to see how KOReader would handle it.

Now, I know that the algorithm is for KOReader to use any fonts explicitly defined if it exists in the font folder or if it's embedded in the epub, and fallback to a single font if all of that fails. But I was wondering if it was possible to set the fallback fonts for the other generic font families explicitly?

For example, it looks like monospace is set properly and it is pulling a monospace font from somewhere (either Droid Sans Mono or Nimbus Mono; I can't tell), but it doesn't do it for the other generic font families (so if I have Charis SIL set as my default font (which is serif), it'll also use it for text set to use generic sans-serif if no other specific font is specified).

Having no explicit fallback font for Fantasy and Cursive I can understand, but as KOReader ships with a variety of serif and sans-serif fonts by default, at the very least, it should be safe to define specific fonts to fallback on for those generic families. Is there a place that I can specify that where it won't get over-written when KOReader gets updated, and if so, where? I'm assuming it'd be a CSS thing unless there's a specific KOReader application option somewhere that I'm missing?

[pazos]

AFAIK there's only one fallback font defined by the user and is used to render glyphs that can't be rendered by your default font.

Feel free to open a question on github, where these kind of questions are more than welcome.

[NiLuJe]

IIRC, we've covered the subject somewhat in a few possibly-completely-unrelated PRs in CRe ^^. Look for stuff from @poire-z and me, at least.

The gist of it being: because reasons. (I think? ).

[rtiangha]

Originally Posted by NiLuJe

IIRC, we've covered the subject somewhat in a few possibly-completely-unrelated PRs in CRe ^^. Look for stuff from @poire-z and me, at least.

The gist of it being: because reasons. (I think? ).

Good technical reasons rather than purely philosophical I hope, lol? :P

I was rather surprised that on my Kobo device, it'd pull its default of Georgia/Avenir Next for generic serif/sans serif when set to Publisher's Default, but couldn't pull a monospace one for kepubs (of course, the whole monospace thing being a known point of contention on Kobo at the moment, lol). I was hoping KOReader could do all three, at least.

I just figured that if the monospace font was set somewhere, there's no reason why any of the other generic font families couldn't be set either, (certainly for serif and sans-serif since some already ship in the stock distribution, although I'm sure there are some nice Open SIL fonts out there that could serve as generic fallbacks for cursive and fantasy too; Calibre on my Windows machine seems to pull Comic Sans and Impact for those respectively, which I found funny). I do understand the need for a single fallback font for when absolutely all else fails, though (one of the Notos being a good choice).

[Frenzie]

Originally Posted by rtiangha

Good technical reasons rather than purely philosophical I hope, lol? :P

I wouldn't be inclined to call them good (it almost feels like a temporary hack to me in the way it works), but these things basically come down to the fact that CREngine implemented something a certain way and that's just the way it is unless someone puts in some (possibly quite serious) effort.