Any way to disable font hinting in stock reader?

[lensmann]

Originally Posted by Colonel Cathcart

No problem at all. And no, I got no word back other than acknowledging the issue. If I remember correctly I was told it's being escalated, but so far it hasn't been fixed. I just checked with the latest firmware.
It wouldn't hurt if more people with this or similar issue will report it, maybe then it'll get a bit more attention?
The reference number for my report is 3762075. Mind you, I reported some other issues I found while I was at it.

Thanks - this is useful. Could I ask which fonts failed for you? I'd like to take a closer look at their structure.

Basically, OpenType fonts include a glyph positioning table (GPOS). One of the actions this table supports is contextual positioning. Contextual positioning tells the renderer where exactly to put combining diacritics - for example, that a pasekh combined with an alef should display at the very bottom of the character, whereas a pasekh combined with a kuf should come under the curve and not at the bottom, and a pasekh combined with tsvey yudn should come in the middle of the space for the glyph centred under the yudn and not at the bottom. Likewise for other nikkudim, e.g. the difference in the positioning of a khoylam when over a vov (centred on top) as opposed to over an alef (top right corner).

Your screenshots seem to confirm my theory that contextual positioning isn't working for some Hebrew fonts, so looking into how the fonts are set up might help figure out precisely what's failing. Giving Kobo those details may help speed up their release of a fix. I have a holiday coming up and this seems like a nice project to take on then.

[Colonel Cathcart]

Originally Posted by lensmann

Thanks - this is useful. Could I ask which fonts failed for you? I'd like to take a closer look at their structure.

Basically, OpenType fonts include a glyph positioning table (GPOS). One of the actions this table supports is contextual positioning. Contextual positioning tells the renderer where exactly to put combining diacritics - for example, that a pasekh combined with an alef should display at the very bottom of the character, whereas a pasekh combined with a kuf should come under the curve and not at the bottom, and a pasekh combined with tsvey yudn should come in the middle of the space for the glyph centred under the yudn and not at the bottom. Likewise for other nikkudim, e.g. the difference in the positioning of a khoylam when over a vov (centred on top) as opposed to over an alef (top right corner).

Your screenshots seem to confirm my theory that contextual positioning isn't working for some Hebrew fonts, so looking into how the fonts are set up might help figure out precisely what's failing. Giving Kobo those details may help speed up their release of a fix. I have a holiday coming up and this seems like a nice project to take on then.

I think you might be right, since:
1. All the rendering problems are in such cases (that I can see, anyway).
2. If the source of the problem is with hinting, wouldn't increasing text size hide the problem? I tried that and the problems persists.

The font is FrankRe: https://alefalefalef.co.il/en/font/frank-re/
I'm not sure if it's a good idea to share it. Probably not.

[lensmann]

Originally Posted by Colonel Cathcart

I think you might be right, since:
1. All the rendering problems are in such cases (that I can see, anyway).
2. If the source of the problem is with hinting, wouldn't increasing text size hide the problem? I tried that and the problems persists.

The font is FrankRe: https://alefalefalef.co.il/en/font/frank-re/
I'm not sure if it's a good idea to share it. Probably not.

Ah, I see. I don't have FrankRe, but the font that prompted my post is also from AlefAlefAlef, and I'd guess all their fonts take a similar approach to nikkudim. I'll report back once I've compared its GPOS tables with those in the Noto fonts.

[Colonel Cathcart]

Originally Posted by lensmann

Ah, I see. I don't have FrankRe, but the font that prompted my post is also from AlefAlefAlef, and I'd guess all their fonts take a similar approach to nikkudim. I'll report back once I've compared its GPOS tables with those in the Noto fonts.

Thank you!
At the time, I did a bit (just a bit) of digging myself and noticed that Kobo's Noto Serif font is not identical to the one freely available on the google fonts site. I wrote about it here:
https://www.mobileread.com/forums/sh...26#post4326026