How to force a horizontal layout for a vertical EPUB?

[Soul-Kim]

When I open an EPUB that is natively formatted in vertical writing mode (specifically a Japanese book), I find that I cannot force it to switch to a horizontal layout for reading.

I have already tried setting publisherStyles = false in my EPUBPreferences, but the text still displays vertically.

I also tested with the TestApp, trying various combinations of settings, but it still wouldn't switch to a horizontal display.

[mickael-menu]

Hi, do you have a sample EPUB you could share, and explain a bit more what you expect for the user experience? We're not super familiar with vertical EPUBs, even though they should be supported by Readium.

Have you tried changing the "vertical text" and "scroll" preferences in the Test App?