Strange waving mark on vertical CJK content about swift-toolkit

[JayPanoz]

Hmmm, looks like an overlapping issue because the line-height is solid there – that’s weird because we give more room to CJK and the default line-height is 20% bigger than for latin scripts.

As for the wave I have difficulties defining whether this is text-emphasis-style with a custom string, text-underline-style: wavy and or a background-image – which is a popular technique for such things.

[JayPanoz]

On a related note, I can also see missing characters in both screenshots (they happen to be the same one):

[iaomw]

https://drive.google.com/file/d/1CSZXEscGXkdNharMjOknYc82CJEXyvZ1/view?usp=sharing
Testing sample

[JayPanoz]

OK so it’s a background-image

span.kindle-cn-specialtext-double{
	 background-image: url(../Images/image00788.gif);
	 background-repeat: repeat-y;
	 background-size:1em 1em;
	 background-position: 0% 0%;
	 padding-left: 0.15em;
	 margin-bottom: 0em ;
}

And here’s the GIF:

What’s weird is that line-height in r2 looks like normal while it should be the result of https://github.com/readium/readium-css/blob/master/css/src/modules/ReadiumCSS-base.css#L38 with a compensation of 1.167 (https://github.com/readium/readium-css/blob/master/css/src/modules/ReadiumCSS-base.css#L197)

What’s strange is that this is the line-height I get, which is very different from the one in the first screenshot:

A couple of extra notes:

1. the file is ePub 2 (not EPUB3)
2. it is specifically authored for Kindle (all class names start with kindle)
3. It is using <meta content="vertical-rl" name="primary-writing-mode" /> (cf. compat doc) in addition to page-progression-direction.

I’m assuming this wasn’t a Kindle Mobi file converted back to EPUB as it lacks some meta artifacts you’ll typically find in such retro-conversions… but maybe I’m wrong?

[JayPanoz]

Also extra notes related to readium/architecture#70

cc @HadrienGardeur and @llemeurfr

If this isn’t retroconverted, that could be either an exception or the rule, in which latter case… the number of such files could be massive on markets we are not necessarily familiar with.

[mickael-menu]

From what I gather it's nothing we can fix in the Swift projects directly. Feel free to reopen the issue with more details on how to fix this in Swift if I misunderstood.