Re: strut problem

[Werner LEMBERG]

>> It would be necessary to add another property to stencils, say, an
>> 'active' flag, so that they can be intentionally taken out of a
>> skyline.
>
> YAGNI. Just use ly:stencil-outline.

OK.

> Are you mindful that ly:make-stencil is a low-level function? If you
> use it, you need to have an understanding of how stencils work at
> the low level.
>
> I don’t see what we would gain by changing those internals.

No problem.  I'm only thinking aloud :-)

>> What I want is to have the `\strut` command work in general.  If
>> this is not possible – for the reason you've outlined – it should
>> be deprecated, together with some documentation that explains why
>> struts don't work (or are the wrong concept) in LilyPond.
>
> As said above, LilyPond considers the outline of stencils in
> addition to their extents (unlike LaTeX, AFAIK), and the skylines of
> text with \strut will depend on where \strut is put.
>
> So I lean towards the second option.

Me, too.

  https://gitlab.com/lilypond/lilypond/-/issues/6473

>>> For example, you could have a markup command that takes a string
>>> and typesets it while giving it the extents + outline of a box
>>> around it encompassing the height of potential ascenders and
>>> descenders.
>>
>> Maybe a more generic solution?
>>
>> ```
>> \with-added-skyline markup1 markup2 [offset [extent]]
>> \with-replaced-skyline markup1 markup2 [offset [extent]]
>> ```
>
> \with-replaced-skyline sounds a lot like
>
>   \with-outline
>     \translate #'(offset . 0) markup2 markup1
>
> \with-added-skyline sounds like
>
>   \with-outline
>     \overlay { markup1 \translate #'(offset . 0) markup2 } markup1

Excellent, thanks.

> Supporting the 'extent' parameter would take some modifications to
> the C++ code. Do you have a specific use case for it?

No.  I was just envisioning the most general case.


    Werner