[Lilypond-auto] Issue 2792 in lilypond: [Doc]FootnoteItem positioning

[lilypond]

Status: Accepted
Owner: ----
Labels: Type-Documentation

New issue 2792 by address@hidden: [Doc]FootnoteItem positioning
http://code.google.com/p/lilypond/issues/detail?id=2792

Reported by Trevor Daniels:
http://lists.gnu.org/archive/html/bug-lilypond/2012-08/msg00178.html

While considering how to add a footnotes to TextScript I came across
this, which could be intended or a bug.  If the positioning number pair
is set to #'(0 . 0) the footnote mark is located in both x and y directions
on the centre of the TextScript object, but if the values are set to any
non-zero value the offsets are calculated from the top-right corner of the
TextScript object.  So to position the mark where it would normally be
after text you have to set the values to any tiny non-zero value.

Here's an example to play with:

\book {
  \header { tagline = ##f }
  \relative c' {
    a'4 b8
    \once \override Staff.FootnoteItem #'annotation-line = ##f
    \footnote  #'(0.0001 . 0.0001) #'TextScript \markup { "Prout has rall."  
}
\default
    e^\markup { "rit." } c4 d4
  }
}

It would be better if #'(0 . 0) resulted in the correct positioning for
TextScript.

Other comments:
http://lists.gnu.org/archive/html/bug-lilypond/2012-08/msg00179.html
http://lists.gnu.org/archive/html/bug-lilypond/2012-08/msg00180.html

Excerpt from the second one:

> if a coordinate is positive, you go from the upper respectively right
> border, if it is negative, from the lower respectively left border, if
> it is zero, from the center.  That makes _perfect_ sense as long as at
> least one coordinate is non-zero.  If _both_ are zero, how to choose
> among the 8 possible border points?

That's sensible enough, but it needs documenting.  I'll add it to my
list of things to do to document footnotes.