I observed a number of things, but I'm not sure whether they're built-in
features / restrictions or whether they're bugs:
1. when using only 'left' or 'right' position specifier, notes in unison
or a second apart will have overlapping fingerings (measures 2, 3 &
9)
2. you cannot specify 'left' and 'right' at the same time to mean "left
or right" (measure 9)
3. providing an empty position specifier list does not work as described
in the documentation (it should hide the fingerings - which it doesn't)
(measure
4. two notes in unison can have fingerings added to the wrong notehead
(measures 7 & 8)
5. why are fingerings of unison notes never displayed at the same height
(vertical position)?
Here's a short yet rather exhaustive example snippet displaying the
actual output for 10 different combinations of fingering placement
specs:
%%%% BEGIN snippet
\version "2.16.2"
theChord =
{ <e-1 cis'-3 g'-2 a-0>4 <e-1 e-3 g'-2 a-0> }
theMusic =
\new Staff {
\relative c, {
\key c
\major
\time 2/4
\clef
"bass"
\override
Score.RehearsalMark #'self-alignment-X = #LEFT
\override
Score.BarNumber #'break-visibility = #'#(#f #t #t)
\set
Score.barNumberVisibility = #(every-nth-bar-number-visible
1)
\override Score.BarNumber
#'stencil
= #(make-stencil-boxer 0.1 0.25
ly:text-interface::print)
\bar
""
\mark \markup{ \rounded-box { "default" } }
|
\theChord
\mark \markup{
\rounded-box { "right" } } |
\set fingeringOrientations
= #'(right)
\theChord
\mark
\markup{ \rounded-box { "left" } } |
\set
fingeringOrientations = #'(left)
\theChord
\mark \markup{ \rounded-box { "up" } }
|
\set fingeringOrientations =
#'(up)
\theChord
\mark
\markup{ \rounded-box { "down" } } |
\set
fingeringOrientations = #'(down)
\theChord
\mark \markup{ \rounded-box { "empty
(spawns warning)" } } |
\set fingeringOrientations =
#'()
\theChord
\mark \markup{
\rounded-box { "up left down" } } |
\set
fingeringOrientations = #'(up left down)
\theChord
\mark \markup{ \rounded-box { "up right
down" } } |
\set fingeringOrientations = #'(up right
down)
\theChord
\mark \markup{
\rounded-box { "left right" } } |
\set
fingeringOrientations = #'(left right)
\theChord
\mark \markup{ \rounded-box { "up down" }
} |
\set fingeringOrientations = #'(up
down)
\theChord
\bar
"|."
}
}
\score {
\theMusic
\layout
{}
}
%%%% END snippet