[Bug] There is an issue with text rotation when using text-keep-upright

[jklee84]

maplibre-gl-js version: 5.0.1

browser: chrome (latest)

Steps to Trigger Behavior

1. Set symbol-placement in layout to line
2. Set text-keep-upright in layout to true
3. Check the map
4. The text rotates to follow the line, but numbers do not rotate as expected

Link to Demonstration

https://jsbin.com/hucaripeja/

Expected Behavior

• text-keep-upright should provide a consistent display when symbol-placement is set.
• It would be ideal if numbers between CJK characters were oriented in the same direction as the CJK characters.

Actual Behavior

• The behavior differs depending on whether the text is in a CJK language.

[HarelM]

Thanks for taking the time to report this issue.
Can you please create a jsbin/codepen to showcase this bug?

[jklee84]

Thanks for taking the time to report this issue. Can you please create a jsbin/codepen to showcase this bug?

@HarelM Thanks for your attention.

I created an example here:
https://jsbin.com/hucaripeja/

I also tried to fix these problems. #5405
Result is here.

[HarelM]

Thanks! @1ec5 can you take a look at this?
A PR, even a draft one, would be better to see the code changes, and see if it affects other tests...

[jklee84]

@HarelM Got it. I’ll create a PR. I hope it gets welcomed! :)

[1ec5]

This feature is called tate-chu-yoko in Japanese and also occurs in Korean (not sure what it’s called there). I agree that this would be very good to have. Not only digits but also Latin letters should remain upright as long as they aren’t part of a longer run of Latin text.

In Japanese, it’s possible to combine two or sometimes three Western characters in the same frame as well. Multi-character tate-chu-yoko would be an extra nicety, but probably not as important as single-character tate-chu-yoko.

/ref mapbox/mapbox-gl-js#3588

[jklee84]

@1ec5 In korean say, "세로쓰기" (se ro ssu gi)
It means vertical writing. 😄

https://upload.wikimedia.org/wikipedia/ko/d/d8/Sero.png