Re: make \breath (kind-of) ignore clef change

[Jean Abou Samra]

Le 01/06/2022 à 21:50, David Kastrup a écrit :
> Frankly, I have no idea what I am actually doing there with the
> ly:stencil-aligned-to . I was just fudging around until something fell
> out that looked like what you wanted to be doing. So "\squashed" is
> actually a misnomer from the first attempt where I just thought I'd
> shrink stuff (which did not work).
> So while the technique for diddling with a stencil is programmed in a
> straightforward manner, I have no clue about the underlying core action.


https://lilypond.org/doc/v2.23/Documentation/internals/breathingsign
indicates that BreathingSign.space-alist.time-signature defaults to
#'(minimum-space . 1.5). The minimum-space spacing style is
defined by this in break-alignment-interface.cc:

          /* should probably junk minimum-space */
          else if (scm_is_eq (type, ly_symbol2scm ("minimum-space")))
            offsets[next_idx] = std::max (extents[idx][RIGHT], distance);

Namely, it measures the minimum distance from the left
grob's X reference point to the right grob's, with
care to ensure that the right grob's reference point
is not further to the left than the right of the
left grob's extent. If the extent of the grob on the
right sticks out to the left, that part isn't taken
into account. So you're effectively making that distance
measured to the right of the time signature rather than
to the left.

I'm not sure why this takes into account the right
endpoint of the extent on the left but not the left
endpoint of the extent on the right. I think it
might just be assuming that all break-aligned grobs
have an extent starting at 0.