ſ (Long-S, Medial-S) not showing on iOS in ePub

Question

ſ (Long-S, Medial-S) not showing on iOS in ePub

Hi all,

Yesterday I successfully created an ePub containing a historical novel set in a blackletter font. Font embedding and font display works fine so far, but what isn't working is the "Long-S" (ſ Unicode U+017F)uſed in blackletter and historical texts frequently. Somehow it seems to be mapped to an "end-s" (normal s).

On Mac OS Mountain Lion, showing the "index.html" of the ePub in Safari works fine, however, it even seems to get the ligatures right most of the time.

Any ideas on how to resolve this and get iBooks show the "ſ" correctly?

Posted on Jun 27, 2013 1:31 AM

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Answer 1

Tom Gewecke

Level 10

115,922 points

Jun 27, 2013 2:52 AM in response to procrastinator

Are you sure the text contains U+017F and is not relying on a typographical variant of normal s? Is there some way to download the view your .epub?

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Answer 2

Jun 27, 2013 6:03 AM in response to Tom Gewecke

Yes, the HTML source contains this character both as an entity reference and the unicode glyph.

On

https://www.icloud.com/photostream/de-de/#A45qXGF1Qxyzs

there is a public photostream with three images in it. The first one shows HTML source, the second one is how it is rendered in Safari on Mac OS, and the third is how it looks on an iPhone 5 with iOS 6. The screenshot is from Safari, but in iBooks on iOS on this particular iPhone, it looks exactly the same.

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Answer 3

Tom Gewecke

Level 10

115,922 points

Jun 27, 2013 8:06 AM in response to procrastinator

How exactly are you transferring your .epub file to your iOS device?

Does your .epub file look ok on your non-iOS device using something like Calibre or Adobe Digital Editions?

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Answer 4

Jun 27, 2013 1:08 PM in response to Tom Gewecke

I transferred the file via Calibre to iTunes and it was synced to iPhone from there. And yes, it looks OK in Calibre. Adobe Digital Editions gets the ſ right, but doesn't support the combined umlauts (a,u,o combined with a small superscript "e").

Anyway, I doubt that it is an issue with the file transfer between devices, since the example screenshots I published on Fotostream are both created by accessing the same index.html on a local HTTP server from the unzipped ePub with Safari, and the font is embedded using standard CSS techniques. The font is a TrueType font, as opposed to OpenType, which seems to be mandated by HTML standards, but it is still surprising that Safari on Mac OS is OK and on iOS it simply shows a standard "s".

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Answer 5

Tom Gewecke

Level 10

115,922 points

Jun 27, 2013 1:25 PM in response to procrastinator

procrastinator wrote:

it is still surprising that Safari on Mac OS is OK and on iOS it simply shows a standard "s".

More than surprising! I don't know of any process by which a hardcoded U+017f could be displayed as a standard "s". I think it would require some kind of "normalization" to replace characters by their Unicode compatiblity decomposition on the way to the ibooks app.

iBooks Author automatically embeds fonts, and I have no problem generating a test book that displays this character correctly in iBooks using fonts not present in iOS.

Have you experimented using any different fonts specified in your css to see if the same thing happens?

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Answer 6

Jun 27, 2013 1:56 PM in response to Tom Gewecke

Yes, in the meantime I found out that it could actually be an issue with the font itself. The typographic system or something in that font seems to have an automatic detection of when - according to german writing rules - in historical texts the "long-s" is supposed to be used, and automatically translates normal "s" to "long-s", so setting the glyph explicitly to U+017F seems to confuse this logic somehow. I don't know whether this is something that could be programmed into a font, but this is so far the only explanation I could find. In the same way it seems to insert ligatures where they belong according to blackletter typesetting rules, but it sometimes seems to get it wrong, because ligatures should never span syllable boundaries, which however they sometimes do with that font. It is called "LFOAtlantisFraktur".

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Answer 7

Tom Gewecke

Level 10

115,922 points

Jun 27, 2013 2:29 PM in response to procrastinator

procrastinator wrote:

Yes, in the meantime I found out that it could actually be an issue with the font itself.

Interesting! I see they have few different types you can choose from

http://www.ligafaktur.de/Schriften.html

In my simple test I used a font called UnifrakturMaguntia

http://unifraktur.sourceforge.net/maguntia.html

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Answer 8

Jun 27, 2013 2:48 PM in response to Tom Gewecke

Thanky you, now I tried with a different font from the same free font site, specifically designed for web use: LFUWeiynckNetz.woff. Now everything works as expected!

Cheers,

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