Re: Accidentals centred above notes

[Richard Shann]

On Thu, 2014-08-07 at 09:45 +0100, Richard Shann wrote:
> On Thu, 2014-08-07 at 08:26 +0100, Phil Holmes wrote:
> > ----- Original Message ----- 
> > From: "Richard Shann" <address@hidden>
> > To: <address@hidden>
> > Sent: Thursday, August 07, 2014 7:58 AM
> > Subject: Accidentals centred above notes
> > 
> > 
> > > The example given in the docs for placing a sharp on a prall results in
> > > a sharp which seems slightly too far to the left:
> > > http://www.lilypond.org/doc/v2.18/Documentation/notation/expressive-marks-attached-to-notes#articulations-and-ornamentations
> > >
> > > \version "2.18.0"
> > >
[...]
> > 
> > It looks like the use of the \sharp markup does indeed put the sharp sign 
> > somewhat left.
> 
> I occurred to me after I wrote that this is to do with the default
> alignment of markup with notes (and the position of the reference point
> of the glyph - the | character you use seems to have its reference point
> to the left of the vertical line). So what is perhaps needed is
> something to tell LilyPond to center markup over the object it is
> attached to. (I looked at \center-column, but, of course, this just
> centers successive lines of text, the whole column itself is aligned to
> the left of the note).
> 
> >   It looks to me like the ficta sharp is correctly aligned on 
> > the notehead.
> You are right, I was wrong - probably an example of seeing what I was
> expecting to see - sorry!
> 
> I'll start digging around for what the syntax is to align markup other
> than on the left side of notes - if anyone can just tell me I would be
> grateful.

I have come up with this:

\version "2.18.0"
\relative c''' {
\once \override TextScript.self-alignment-X=#'-1.5  a2 ^\markup { \tiny
\sharp}
\set suggestAccidentals = ##t ais
}

the docs (
http://www.lilypond.org/doc/v2.18/Documentation/internals/self_002dalignment_002dinterface
 ) say:
"
 self-alignment-X (number)

    Specify alignment of an object. The value -1 means left aligned, 0 
centered, and 1 right-aligned in X direction. Other numerical values may also 
be specified. 
"

which doesn't give much clue as to what the units are... (if I'm looking
at the right thing)

Richard