Ictus / episema stacking order

[fiat96]

This mess of a neum appears in Good Friday Tenebrae's first responsory:

In my printed Liber it is more obvious that there is indeed an ictus above the staff over the third note. I don't think there is anything in gabc to handle this as of now, but I may just be missing something. If not, perhaps '2 or r9 could work?

[rpspringuel]

Are you sure it's an ictus and not a reversed accentus?

[fiat96]

Pretty sure.

This (poor quality) scan from my Liber is still ambiguous, but more vertical than the above:

But this scan from the 1925 Officium Hebdomadae Sanctae is pretty clear that there's an ictus on that note, even if this source omits the horizontal episema:

Of course,it would be simple to write the chant in gregorio to look like the OHS image above; but trying to put an ictus and an episema above the note, as in the Liber, simply causes a collision.

[rpspringuel]

I don't get a collision when compiling this: plà(e!fwg_'hi). Now, the episema is above the ictus (the opposite of what you depicted), but the two don't collide. How are you encoding this that you get a collision?

Even with no collision, it might be worth having a control over stacking order when an ictus and episema appear on the same side of a note.

[fiat96]

I can't reproduce the collision I got back in March, and I've lost my old file. I think I was trying to manually move the elements, and I was using an older version of gregorio.

You hit the crux of the matter when you mentioned controlling the stacking order - that's really what I'm looking for. I'll change the issue title accordingly.

[rpspringuel]

This is not going to be as easy to change as I thought as the heights for the ictus and episema are chosen by the command-line tool. @henryso any ideas on whether (and how) it might be possible to allow the user to control the stacking order that the command-line tool picks?

[henryso]

It's not possible (other than some <v> magic) to do this currently. If we want to implement it, we'll need some clear gabc notation for it and a bunch of time.

[fiat96]

Just for the record, I came across another case of this with our schola when practicing for next Sunday: https://gregobase.selapa.net/chant.php?id=2196

d!ewf_' produces:

Perhaps it would be possible simply to change the default setting for these cases to place the episema closer to the note than the ictus? I cannot recall any cases of the opposite in the liturgical books, and (to me) it looks more aesthetically pleasing.

[henryso]

Is there any objection to this proposal?