Horizontal page turning of vertical text

[itok]

Hello. (Thank you for answering my question last time.)

How can I flip a vertically written text for horizontal page turning? (not scroll)

Best Regards.

[mickael-menu]

I'm not sure I understand what you mean. Is this what you expect?

paginated-vertical.mov

[itok]

Thanks for response.
In vertically written text, page turning occurs vertically within the same xhtml, and page turning occurs horizontally when crossing xhtml.
We want this to always be a horizontal page turn.

Simulator.Screen.Recording.-.iPhone.15.Pro.-.2023-12-20.at.10.59.19.mov

[mickael-menu]

I see, unfortunately I don't think it's possible to have vertical text with horizontal paginated mode (scroll = false). The reason is technical, we use CSS columns to paginate the content, and web views lay out the columns vertically when using writing-mode: vertical-lr. But I'm not an expert on this subject, you may want to open an issue on the Readium CSS project where this is handled.

[itok]

Thank you for reply.
I'll ask on the Readium CSS project.

[qnga]

Hi,
Does this paginated mode still make any sense to you if page turning has to be vertical? Or would you just use the scroll mode instead?

[JayPanoz]

As a confirmation of sorts, this is indeed due to a limitation of CSS multicolumn, which was discussed in ReadiumCSS 4 years ago: Chinese epub vertical documents cannot be read normally

Some background. On iOS, the pagination API used by iBooks is built on top of columns and is using non-standard properties in Webkit to achieve what’s requested here, but ReadiumCSS has to support all major platforms & these props were removed in Chrome at the time they removed CSS regions.

It’s also been made crystal clear they won’t ever be added into the CSS multicol spec, as such issues belong to a CSS fragmentation module. There are some additional details in the ReadiumCSS docs.

So the only way to achieve that, more or less, is to cheat at the moment – e.g. swiping horizontally scrolls vertically w/o an animation.

[danielweck]

in Thorium we disable "pagination" (i.e. CSS columns) when rendering vertical writing mode (to be precise: right-to-left VWM for Japanese, which is the only implementation that has been tested and validated, by Japanese users).
We do implement "pagination" in the sense of scrolling the viewport horizontally by an offset corresponding to the visible scroll extent (that's the standard scrolling behaviour for previous/next commands in Thorium anyway, nothing special here).
Bottom line: CSS columns support in Chromium (and I suspect in other web browser engine too) "works" but there are many footguns and undocumented quirks which make it hard to achieve predictable / reliable rendering of vertically flowing text with all our other reading system features (annotation highlights, margin indicators etc. etc.) So we gave up trying :)

[mickael-menu]

Thanks for your feedback Daniel, that's very insightful! We'll probably do the same thing on mobile.