Asciidoctor :: Discussion

CJK support in PDF: state of the art?

_‹ Previous Topic Next Topic _›

Classic

List

Threaded

10 messages Options

craftyjon

Feb 21, 2021; 2:50pm

CJK support in PDF: state of the art?

2 posts

Hi all,

I'm working on a project to move a translated documentation package to
asciidoctor (hi Marco!)

We need PDF output support with CJK characters, and I've hit a dead
end trying to get this to work.

It seems like back in 2015 this was solved by Rei's work on
asciidoctor-pdf-cjk-kai_gen_gothic, but this package is no longer
maintained and the font KaiGen Gothic seems to not be widely available
anymore, so this option seems to not be a good idea.

I assumed that using Noto Serif CJK would be a good path, as this font
family looks good, has an appropriate license, and has lots of
characters supported.

Unfortunately, I have not been able to make it work with
asciidoctor-pdf. As it seems like people have noted before on other
threads, it causes ttfunk to crash.

I have tried various things suggested in the asciidoctor-pdf
documentation for "repairing" the font in FontForge, however FontForge
seems to have trouble dealing with this font, and none of the steps
suggested in the docs result in a font that ttfunk can use.

So, before I get into the weeds with any of the particulars of getting
Noto Serif to work, I ask the community: is anyone generating PDFs
with CJK characters using anything other than the (now-unsupported)
KaiGen Gothic gem and an openly-licensed font? If so, can you please
advise which font you used and if you had to do any magic steps to get
ttfunk to accept it?

Best,
Jon

danyill

Feb 21, 2021; 8:43pm

Re: CJK support in PDF: state of the art?

7 posts

Have you tried using https://github.com/Mogztter/asciidoctor-web-pdf?

Although this hasn't had a formal release yet (still in alpha), I've had good experience with it.

More generally the use of web technologies generally will probably allow higher complexity than asciidoctor-pdf supports at present because of the considerable investment for i18n in browsers

On Mon, Feb 22, 2021 at 3:50 AM craftyjon [via Asciidoctor :: Discussion] <[hidden email]> wrote:

Hi all,

I'm working on a project to move a translated documentation package to
asciidoctor (hi Marco!)

We need PDF output support with CJK characters, and I've hit a dead
end trying to get this to work.

It seems like back in 2015 this was solved by Rei's work on
asciidoctor-pdf-cjk-kai_gen_gothic, but this package is no longer
maintained and the font KaiGen Gothic seems to not be widely available
anymore, so this option seems to not be a good idea.

I assumed that using Noto Serif CJK would be a good path, as this font
family looks good, has an appropriate license, and has lots of
characters supported.

Unfortunately, I have not been able to make it work with
asciidoctor-pdf. As it seems like people have noted before on other
threads, it causes ttfunk to crash.

I have tried various things suggested in the asciidoctor-pdf
documentation for "repairing" the font in FontForge, however FontForge
seems to have trouble dealing with this font, and none of the steps
suggested in the docs result in a font that ttfunk can use.

So, before I get into the weeds with any of the particulars of getting
Noto Serif to work, I ask the community: is anyone generating PDFs
with CJK characters using anything other than the (now-unsupported)
KaiGen Gothic gem and an openly-licensed font? If so, can you please
advise which font you used and if you had to do any magic steps to get
ttfunk to accept it?

Best,
Jon

If you reply to this email, your message will be added to the discussion below:
https://discuss.asciidoctor.org/CJK-support-in-PDF-state-of-the-art-tp8529.html

To start a new topic under Asciidoctor :: Discussion, email [hidden email]
To unsubscribe from Asciidoctor :: Discussion, click here.
NAML

... [show rest of quote]

Private or confidential message? Public Key available here:

Alexander Schwartz

Feb 21, 2021; 9:20pm

Re: CJK support in PDF: state of the art?

48 posts

In reply to this post by craftyjon

That question came up related to the IntelliJ AsciiDoc plugin. I summarized some of it in the users manual here: https://intellij-asciidoc-plugin.ahus1.de/docs/users-guide/features/advanced/pdf-non-latin-languages.html

My understanding is that you need asciidoctor-pdf, TTF fonts placed in the right folder and a theme. I am not sure about the current state of OTF support.

The KaiGen Gothic fonts are available here: https://github.com/minjiex/kaigen-gothic/tree/master/dist/CN.

I can't read/write Chinese, but AFAIK the solution worked for diguage. See the link above for a working example.

A search on GitHub revealed some alternative Source Han Sans ready-build TTF fonts here: https://github.com/be5invis/source-han-sans-ttf

Alexander Schwartz (alexander.schwartz@gmx.net)
https://www.ahus1.de

mojavelinux

Feb 21, 2021; 9:21pm

Re: CJK support in PDF: state of the art?

Administrator

2681 posts

In reply to this post by craftyjon

Jon,

Asciidoctor PDF does have support for CJK languages. Many of the discussions you cited about problems with it are outdated.

The instructions for how to get the full range of support for CJK can be found in the README here: https://github.com/asciidoctor/asciidoctor-pdf#support-for-non-latin-languages, with specific steps listed here: https://github.com/asciidoctor/asciidoctor-pdf#create-a-custom-cjk-theme. If you run into problems following those steps, please report an issue and we'll fix it.

The asciidoctor-pdf-cjk-kai_gen_gothic itself is still relevant. Though all it does is download the fonts to your system. You can download the fonts anyway you choose.

I also second @danyill's point about considering Asciidoctor Web PDF. The browser normalizes nearly all the complexities of dealing with fonts, so being able to leverage that platform makes life a whole lot simpler.

Best Regards,

-Dan

Dan Allen (he, him, his) | @mojavelinux | https://twitter.com/mojavelinux

mojavelinux

Feb 21, 2021; 9:24pm

Re: CJK support in PDF: state of the art?

Administrator

2681 posts

In reply to this post by Alexander Schwartz

Alexander,

This is great information. I'd really like to keep it centralized. Would you consider submitting an update to the Asciidoctor PDF README that includes your approach, possibly replacing the one already there if you think it is going to guarantee success?

Best Regards,

-Dan

Dan Allen (he, him, his) | @mojavelinux | https://twitter.com/mojavelinux

mojavelinux

Feb 21, 2021; 10:03pm

Re: CJK support in PDF: state of the art?

Administrator

2681 posts

In reply to this post by Alexander Schwartz

> I summarized some of it in the users manual here: https://intellij-asciidoc-plugin.ahus1.de/docs/users-guide/features/advanced/pdf-non-latin-languages.html

Keep in mind that you don't need to redeclare any of the bundled fonts. Instead, you can configure the font catalog to merge the additional entries.

extends: default
font:
catalog:
merge: true
cjk: YourCJKFontHere.ttf
base:
font_family: cjk

Best Regards,

-Dan

Dan Allen (he, him, his) | @mojavelinux | https://twitter.com/mojavelinux

mojavelinux

Feb 21, 2021; 10:04pm

Re: CJK support in PDF: state of the art?

Administrator

2681 posts

In reply to this post by craftyjon

I forgot to say, I always start by recommending trying the built-in fallback font. It doesn't have the full range of simplified Chinese characters, but it does cover a good portion of them for occasional references.

asciidoctor-pdf -a pdf-theme=default-with-fallback-font doc.adoc

Best Regards,

-Dan

Dan Allen (he, him, his) | @mojavelinux | https://twitter.com/mojavelinux

mojavelinux

Feb 21, 2021; 10:07pm

Re: CJK support in PDF: state of the art?

Administrator

2681 posts

In reply to this post by craftyjon

> Unfortunately, I have not been able to make it work with
asciidoctor-pdf. As it seems like people have noted before on other

threads, it causes ttfunk to crash.

You're correct that although Asciidoctor PDF now supports OTF (in the mainline branch), the Noto CJK font still does not produce the desired result. The text in the document ends up being blank. I don't know why this is. Regardless, it's outside the scope of this project. It's best to report that to ttfunk (https://github.com/prawnpdf/ttfunk). In the meantime, I recommend finding another font.

Best Regards,

-Dan

Dan Allen (he, him, his) | @mojavelinux | https://twitter.com/mojavelinux

craftyjon

Feb 21, 2021; 11:16pm

Re: CJK support in PDF: state of the art?

2 posts

Thanks everyone for the advice.

asciidoctor-web-pdf looks very promising, I was able to install it and
generate documents with no problems.

I think I will pursue that as the first path since it does not depend
on any particular font, and if any problems come up that I can't get
past, go back to the suggestions Dan made to get things working with
ttfunk.

Best,
Jon

On Sun, Feb 21, 2021 at 5:07 PM mojavelinux [via Asciidoctor ::
Discussion] <[hidden email]> wrote:

>
> > Unfortunately, I have not been able to make it work with
> asciidoctor-pdf. As it seems like people have noted before on other
> threads, it causes ttfunk to crash.
>
> You're correct that although Asciidoctor PDF now supports OTF (in the mainline branch), the Noto CJK font still does not produce the desired result. The text in the document ends up being blank. I don't know why this is. Regardless, it's outside the scope of this project. It's best to report that to ttfunk (https://github.com/prawnpdf/ttfunk). In the meantime, I recommend finding another font.
>
> Best Regards,
>
> -Dan
>
> --
> Dan Allen (he, him, his) | @mojavelinux | https://twitter.com/mojavelinux
>
>
> ________________________________
> If you reply to this email, your message will be added to the discussion below:
> https://discuss.asciidoctor.org/CJK-support-in-PDF-state-of-the-art-tp8529p8536.html
> To start a new topic under Asciidoctor :: Discussion, email [hidden email]
> To unsubscribe from Asciidoctor :: Discussion, click here.
> NAML

... [show rest of quote]

mojavelinux

Feb 22, 2021; 12:19am

Re: CJK support in PDF: state of the art?

Administrator

2681 posts

Glad we got you moving, Jon,

Keep in mind that Asciidoctor Web PDF does depend on a particular font. You just get to leverage the browser for finding it ;)

Best Regards,

-Dan

Dan Allen (he, him, his) | @mojavelinux | https://twitter.com/mojavelinux