Re: Issue with AikenHeads with overlapping parts

[Darren Miller]

Colin, thanks for the quick response.

You're right: it seems that the \ignoreCollide directive was what was
confusing it.  I think I had included that from a sample where it was
supposed to allow the stems to merge in multi-voice.  But, at some point I
changed it to using polyphonic (using the \new Voice for alternate note
arrangements) ... and it must be redundant for that mode.  I took it out
like you suggested, and got the results you show below.

In my full score, it shows the staggered note heads that I was trying to
avoid... but now that I know the culprit, I hopefully can figure out why
the heads are being staggered.

As far as the correct behavior of shaped notes heads when they overlap: one
part or the other's note head should be shown.  If the head has two
different orientations based on whether its stem is up or down, it needs to
avoid creating a different shape by overlapping.  I guess that Fa is the
only one likely to be a problem as the others are symmetrical.  Fa is a
leftward-pointing right triangle when the stem is up.  When the stem is
down, the head is flipped vertically and points the other way.  If allowed
to overlap, the two heads form a box, which isn't right.  But that seems
corrected when they overlap properly.

The only difference I see between the layout this now renders is the facing
of the note head for the D (Fa). I have the same song in a couple books,
and one shows the note head pointing left, as if it were attached to the
soprano part's stem.  The other book shows it pointing right, as does
yours, as if it were attached to the alto part's stem. So I guess that's a
dealer's choice.

Well, I'm going back to expermenting with this, but it seems like a really
powerful program.  (Now I just have to figured out why the full score
needed the ignoreCollide to prevent staggered note heads...)  Thanks for
your help!







On Thu, Mar 22, 2012 at 7:19 PM, Colin Hall <address@hidden> wrote:

>
> On Thu, Mar 22, 2012 at 08:39:00PM +0000, Darren wrote:
> > > I'm not top posting.
> >
> > I'm trying to create a score for four voices SATB that uses AikenHeads
> (shaped
> > notes).  When two parts on the same staff overlap on the same notes (for
> > example soprano and alto), it is customary to show the stems for the two
> parts
> > going different directions so each part realizes that it is to sing the
> > overlapping notes.
> >
> > When I try to do this with LilyPond 2.14.2,
> >
> > 1. The heads face in opposite directions, which obscures the shape of
> the head.
> >
> > 2. I tried suppressing the Note Head for one of the parts (made it
> > transparent), however the stem does not meet the note head of the
> opposite part.
> >
> > Example .ly code follows.  It requires a bit of detail to demonstrate the
> > problem.  I have a screen shot I can provide if that would help (but this
> > interface doesn't accept attachments).
>
> Thanks for putting the bug report together, Darren. I was able to
> reproduce the behaviour you reported.
>
> I also tried removing the \ignoreCollide from your source just to see what
> happens, and I have to say that the output looks correct to me. See
> attached. The notes are both supertonics and the note shape seems correct.
>
> But I've never used Aikenhead notation so I may not be the best judge. I
> will create a tracker so we don't lose your input. In the meantime, could
> you send an example of good practice for colliding Aikenhead notes, or an
> image of what you think Lilypond should do in this situation?
>
> Cheers,
> Colin.
>
> --
>
> Colin Hall
>