shape. Objects with an extended shape like these are called
@q{Spanners}.
+What is more, there are @q{abstract} grobs which do not print
+anything of their own, but rather collect, position and manage
+other grobs. Common examples for this are
+@code{DynamicLineSpanner}, @code{BreakAlignment},
+@code{NoteColumn}, @code{VerticalAxisGroup},
+@code{NonMusicalPaperColumn} and similar. We will see how some of
+these are used later.
+
It remains to explain what @q{Interfaces} are. Many objects, even
though they are quite different, share common features which need to
be processed in the same way. For example, all grobs have a color, a
* The once prefix::
* The overrideProperty command::
* The tweak command::
+* The single prefix::
@end menu
@node The override command
This long form of the @code{\tweak} command can be described as
@example
-\tweak @var{layout-object}.@var{layout-property} @var{value}
+\tweak @var{LayoutObject}.@var{layout-property} #@var{value}
@end example
@cindex tuplets, nested
Notation Reference:
@ruser{The tweak command}.
+@node The single prefix
+@unnumberedsubsubsec The @code{@bs{}single} prefix
+
+@funindex \single
+@cindex tweak, generated from override
+
+Suppose we wanted to emphasize particular note heads by coloring them
+red and increasing their size, and to make it easy suppose also we
+have defined a function to do this:
+
+@lilypond[quote,verbatim]
+emphNoteHead = {
+ \override NoteHead.color = #red
+ \override NoteHead.font-size = 2
+}
+\relative c'' {
+ c4 a \once \emphNoteHead f d |
+}
+@end lilypond
+
+The @code{\once} prefix works fine to emphasize single notes or
+complete chords, but it cannot be used to emphasize a single note
+@emph{within} a chord. Earlier we have seen how @code{\tweak} can
+be used to do this, see
+@ref{The tweak command,,The @code{@bs{}tweak} command}. But
+@code{\tweak} cannot be used with a function; that's where
+@code{\single} comes in:
+
+@lilypond[quote,verbatim]
+emphNoteHead = {
+ \override NoteHead.color = #red
+ \override NoteHead.font-size = 2
+}
+\relative c'' {
+ <c a \single \emphNoteHead f d>4
+}
+@end lilypond
+
+In summary, @code{\single} converts overrides into tweaks so when
+there are several objects at the same point in musical time (like
+noteheads in a chord), @code{\single} will only affect a single one,
+the one generated by the immediately following music expression, in
+contrast to @code{\once} which will affect all of those objects.
+
+By using @code{\single} in this way any shorthand function
+containing just overrides may be applied to individual notes in a
+chord. However, @code{\single} does not convert @code{\revert},
+@code{\set} or @code{\unset} into tweaks.
+
+@seealso
+Learning Manual:
+@ref{The tweak command,,The @code{@bs{}tweak} command},
+@ref{Using variables for layout adjustments}.
+
@node The Internals Reference manual
@section The Internals Reference manual
Here's a further example. We see that the beams
collide with the ties:
-@lilypond[quote,verbatim,fragment,ragged-right]
+@lilypond[quote,verbatim,fragment,ragged-right,relative=1]
{
\time 4/2
<<
- { c'1 ~ 2. e'8 f' }
+ { c1~ 2. e8 f }
\\
- { e''8 e'' e'' e'' e'' e'' e'' e'' f''2 g'' }
+ {
+ e'8 e e e
+ e e e e
+ f2 g
+ }
>>
<<
- { c'1 ~ 2. e'8 f' }
+ { c,,1~ 2. e8 f }
\\
- { e''8 e'' e'' e'' e'' e'' e'' e'' f''2 g'' }
+ {
+ e'8 e e e
+ e e e e
+ f2 g
+ }
>>
}
@end lilypond
@cindex Beam, example of overriding
@cindex positions property, example
-@lilypond[quote,verbatim,fragment,ragged-right]
+@lilypond[quote,verbatim,ragged-right,relative=1]
{
\time 4/2
<<
- { c'1 ~ 2. e'8 f' }
+ { c1~ 2. e8 f }
\\
{
\override Beam.positions = #'(-1 . -1)
- e''8 e'' e'' e'' e'' e'' e'' e'' f''2 g''
+ e'8 e e e
+ e e e e
+ f2 g
}
>>
<<
- { c'1 ~ 2. e'8 f' }
+ { c,,1~ 2. e8 f }
\\
- { e''8 e'' e'' e'' e'' e'' e'' e'' f''2 g'' }
+ {
+ e'8 e e e
+ e e e e
+ f2 g
+ \revert Beam.positions
+ }
>>
}
@end lilypond
@noindent
-Note that the override continues to apply in the first voice of
+Note that the override continues to apply in the second voice of
the second measure of eighth notes, but not to any of the beams in the
-second voice.
+first voice, even those in the later second measure. As soon as the
+override should no longer apply it should be reverted, as shown.
@node The force-hshift property
@unnumberedsubsubsec The @code{force-hshift} property
@noindent
The inner note of the first chord (i.e. the A-flat in the fourth
Voice) need not be shifted away from the note column of the higher
-note. We might expect to correct this by using @code{\shiftOff}, but
-this will cause warnings about clashing note columns. Instead, we
-set @code{force-hshift}, which is a property of @code{NoteColumn},
-of this note to zero.
+note, so we use @code{\shiftOff}.
In the second chord we prefer the F to line up with the A-flat and
the lowest note to be positioned slightly right to avoid a collision
{ <ees, c>2 \once \override NoteColumn.force-hshift = 0.5 des }
\\
\\
- { \once \override NoteColumn.force-hshift = 0 aes'2
- \once \override NoteColumn.force-hshift = 0 f4 fes }
+ { \once \shiftOff aes'2 \once \shiftOff f4 fes }
>> |
<c ees aes c>1 |
}
* Simulating a fermata in MIDI::
@end menu
-@cindex transparent property, use of
-@cindex objects, making invisible
@cindex removing objects
@cindex objects, removing
-@cindex hiding objects
-@cindex objects, hiding
-@cindex invisible objects
-@cindex objects, invisible
@node Tying notes across voices
@unnumberedsubsubsec Tying notes across voices
@cindex tying notes across voices
-The following example demonstrates how to connect notes in
-different voices using ties. Normally, only two notes in the
-same voice can be connected with ties. By using two voices,
-with the tied notes in one of them
+The following example demonstrates how to connect notes in different
+voices using ties. Normally, only notes in the same voice can be
+connected with ties. By using two voices, with the tied notes in one
+of them
@lilypond[quote,fragment,relative=2]
<< { b8~ 8\noBeam } \\ { b8[ g] } >>
@end lilypond
@noindent
-and blanking the first up-stem in that voice, the tie appears to
-cross voices:
-
-@cindex Stem, example of overriding
-@cindex transparent property, example
-
-@lilypond[quote,fragment,relative=2,verbatim]
-<<
- {
- \tweak Stem.transparent ##t
- b8~ 8\noBeam
- }
-\\
- { b8[ g] }
->>
-@end lilypond
+and removing the first up-stem and its flag in that voice, the tie
+appears to cross voices:
-To make sure that the just-blanked stem doesn't squeeze the tie
-too much, we can lengthen the stem by setting the
-@code{length} to @code{8},
+@funindex \omit
+@cindex Stem, example of removing
+@cindex Flag, example of removing
+@cindex @code{\omit}, example
+@cindex example of @code{\omit}
@lilypond[quote,fragment,relative=2,verbatim]
<<
{
- \tweak Stem.transparent ##t
- \tweak Stem.length #8
+ \once \omit Stem
+ \once \omit Flag
b8~ 8\noBeam
}
\\
>>
@end lilypond
-@funindex \single
-@cindex tweak, generated from override
-Now for @emph{overriding} the transparency of a graphical object,
-we could have used the shorthand @code{\hide} as explained above.
-Tweaking is a different operation, affecting only properties
-generated from a single music expression. It turns out that we
-can convert overrides into tweaks using @code{\single}, making it
-possible to rewrite the above example as
-
-@lilypond[quote,fragment,relative=2,verbatim]
-<<
- {
- \single \hide Stem
- \single \hide Flag
- \tweak Stem.length #8
- b8~ 8\noBeam
- }
-\\
- { b8[ g] }
->>
-@end lilypond
+@seealso
+Learning Manual:
+@ref{The once prefix,,The @code{@bs{}once} prefix},
+@ref{The stencil property}.
-In this particular case, the difference to @code{\once \hide} is
-not apparent. It is important when there are several objects at
-the same point in musical time (like noteheads in a chord). In
-that case, @code{\once} will affect all of those objects while
-@code{\single} will only affect a single one, the one generated by
-the immediately following music expression.
@node Simulating a fermata in MIDI
@unnumberedsubsubsec Simulating a fermata in MIDI
projects / lilypond.git / blobdiff