Emanuel Han schrieb am 01.03.2024 um 16:23:
> Dear Wolfgang,
>
> thank you for your valuable remarks. I integrated them, see corrected 
> attached example.
>
> Yes, correct layout examples exist. They're all showing vertical 
> writing, but the rules and principles are exactly the same for 
> horizontal writing.
>
>  *
>     position of the headers and footers:
>     https://www.w3.org/TR/jlreq/#fig1_30

See my attached gongitsune.tex example how you can squeeze text in a 
very narrow header/footer.

>  *
>     aligning lines to the text box: https://www.w3.org/TR/jlreq/#fig1_3

You can use the lines key for \setuplayout to let ConTeXt calculate the 
necessary value for the text height.

>  *
>     protrusion of ruby: https://www.w3.org/TR/jlreq/#fig_ad1_6

You're getting this for free because ruby text doesn't take up vertical 
space, in case vertical text is working it would now stick into the 
margins as expected.

\starttext
\ruledhbox{a \ruby{x}{y} b}
\stoptext


> In my previous mail, I wrote wrong amounts of lines. They should be 46 
> lines on one page, while the actual example doesn't show the 46th line.
>
> It would be important to identify the reason why only 24 characters 
> are used to create a line when 25 could be used. Then we can develop a 
> method to turn that mechanism off or circumvent it.
> Quotation from https://www.w3.org/TR/jlreq:
> /In principle, when composing a line with //ideographic (cl-19) 
> <https://www.w3.org/TR/jlreq/#cl-19>//, //hiragana (cl-15) 
> <https://www.w3.org/TR/jlreq/#cl-15>// and //katakana (cl-16) 
> <https://www.w3.org/TR/jlreq/#cl-16>// characters, no extra spacing 
> appears between their //character frame 
> <https://www.w3.org/TR/jlreq/#term.character-frame>//. This is called 
> solid setting (see //Figure 5 <https://www.w3.org/TR/jlreq/#fig1_8>//)./

1. ConTeXt has a mechanism to typeset Japanese texts.

2. There are flaws in the output it produces but this nothing which 
can't be fixed.

3. To fix the problems someone has to be passionate to fix them and 
we're willing to help here.

As you can see in my second example file japanese.tex there is a font 
feature to create half sized parentheses etc. which isn't supported yet 
by ConTeXt's mechanism for japanese and in case your willing to improve 
it this should be taken care of as well.

Wolfgang