[ << Tweaking output ]	[首页][目录][索引]	[ Templates >> ]
[ < Fingering ]	[ 上 : Placement of objects ]	[ The outside-staff-priority property > ]

5.4.3 Outside-staff objects

Outside-staff objects are automatically placed to avoid collisions. There are several ways to override the automatic placement if the positioning is not optimum.

The outside-staff-priority property
The \textLengthOn command
Dynamics placement
Grob sizing

---

[ << Tweaking output ]	[首页][目录][索引]	[ Templates >> ]
[ < Outside-staff objects ]	[ 上 : Outside-staff objects ]	[ The textLengthOn command > ]

The outside-staff-priority property

Objects with the lower value of the outside-staff-priority property are placed nearer to the staff, and other outside-staff objects are then raised as far as necessary to avoid collisions. The outside-staff-priority is defined in the grob-interface and so is a property of all layout objects. By default it is set to #f for all within-staff objects, and to a numerical value appropriate to each outside-staff object when the object is created. See outside-staff-priority Default values for outside-staff-priority for an exhaustive table.

Note the unusual names for some of the objects: spanner objects are automatically created to control the vertical positioning of grobs which (might) start and end at different musical moments, so changing the outside-staff-priority of the underlying grob will have no effect. For example, changing outside-staff-priority of the Hairpin object will have no effect on the vertical positioning of hairpins – you must change outside-staff-priority of the associated DynamicLineSpanner object instead. This override must be placed at the start of the spanner, which might include several linked hairpins and dynamics.

Here is an example showing the default placement of some of these.

% Set details for later Text Spanner
\override TextSpanner.bound-details.left.text
    = \markup { \small \bold Slower }
% Place dynamics above staff
\dynamicUp
% Start Ottava Bracket
\ottava #1
c''4 \startTextSpan
% Add Dynamic Text and hairpin
c''4\pp\<
c''4
% Add Text Script
c''4^Text |
c''4 c''
% Add Dynamic Text and terminate hairpin
c''4\ff c'' \stopTextSpan |
% Stop Ottava Bracket
\ottava #0
c'4 c' c' c' |

This example also shows how to create Text Spanners – text with extender lines above a section of music. The spanner extends from the \startTextSpan command to the \stopTextSpan command, and the format of the text is defined by the \override TextSpanner command. For more details see Text spanners.

It also shows how ottava brackets are created.

If the default values of outside-staff-priority do not give you the placing you want, the priority of any of the objects may be overridden. Suppose we would like the ottava bracket to be placed below the text spanner in the example above. All we need to do is to look up the priority of OttavaBracket in the table at Default values for outside-staff-priority or in the IR, and reduce it to a value lower than that of a TextSpanner, remembering that OttavaBracket is created in the Staff context:

% Set details for later Text Spanner
\override TextSpanner.bound-details.left.text
    = \markup { \small \bold Slower }
% Place dynamics above staff
\dynamicUp
% Place following Ottava Bracket below Text Spanners
\once \override Staff.OttavaBracket.outside-staff-priority = #340
% Start Ottava Bracket
\ottava #1
c''4 \startTextSpan
% Add Dynamic Text
c''4\pp
% Add Dynamic Line Spanner
c''4\<
% Add Text Script
c''4^Text |
c''4 c''
% Add Dynamic Text
c''4\ff c'' \stopTextSpan |
% Stop Ottava Bracket
\ottava #0
c'4 c' c' c' |

Note that some of these objects, in particular bar numbers, metronome marks and rehearsal marks, live by default in the Score context, so be sure to use the correct context when these are being overriden.

Slurs by default are classed as within-staff objects, but they often appear above the staff if the notes to which they are attached are high on the staff. This can push outside-staff objects such as articulations too high, as the slur will be placed first. The avoid-slur property of the articulation can be set to 'inside to bring the articulation inside the slur, but the avoid-slur property is effective only if the outside-staff-priority is also set to #f. Alternatively, the outside-staff-priority of the slur can be set to a numerical value to cause it to be placed along with other outside-staff objects according to that value. Here’s an example showing the effect of the two methods:

\relative c'' {
  c4( c^\markup { \tiny \sharp } d4.) c8 |
  c4(
    \once \override TextScript.avoid-slur = #'inside
    \once \override TextScript.outside-staff-priority = ##f
    c4^\markup { \tiny \sharp } d4.) c8 |
  \once \override Slur.outside-staff-priority = #500
    c4( c^\markup { \tiny \sharp } d4.) c8 |
}

Changing the outside-staff-priority can also be used to control the vertical placement of individual objects, although the results may not always be desirable. Suppose we would like “Text3” to be placed above “Text4” in the example under Automatic behavior, above (see Automatic behavior). All we need to do is to look up the priority of TextScript in the IR or in the tables above, and increase the priority of “Text3” to a higher value:

c''2^"Text1"
c''2^"Text2" |
\once \override TextScript.outside-staff-priority = #500
c''2^"Text3"
c''2^"Text4" |

This certainly lifts “Text3” above “Text4” but it also lifts it above “Text2”, and “Text4” now drops down. Perhaps this is not so good. What we would really like to do is to position all the annotation at the same distance above the staff. To do this, we clearly will need to space the notes out horizontally to make more room for the text. This is done using the textLengthOn command.

---

[ << Tweaking output ]	[首页][目录][索引]	[ Templates >> ]
[ < The outside-staff-priority property ]	[ 上 : Outside-staff objects ]	[ Dynamics placement > ]

The \textLengthOn command

By default, text produced by markup takes up no horizontal space as far as laying out the music is concerned. The \textLengthOn command reverses this behavior, causing the notes to be spaced out as far as is necessary to accommodate the text:

\textLengthOn  % Cause notes to space out to accommodate text
c''2^"Text1"
c''2^"Text2" |
c''2^"Text3"
c''2^"Text4" |

The command to revert to the default behavior is \textLengthOff. Alternatively, \once may be used with \textLengthOn if the effect is to be limited to just a single musical moment. The corresponding spacing behavior for rehearsal marks and tempo indications is independently controlled with the commands \markLengthOn and \markLengthOff.

Markup text will also avoid notes which project above the staff. If this is not desired, the automatic displacement upwards may be turned off by setting the priority to #f. Here’s an example to show how markup text interacts with such notes.

\relative {
  % This markup is short enough to fit without collision
  c''2^"Tex" c'' |
  R1 |

  % This is too long to fit, so it is displaced upwards
  c,,2^"Text" c'' |
  R1 |

  % Turn off collision avoidance
  \once \override TextScript.outside-staff-priority = ##f
  c,,2^"Long Text   " c'' |
  R1 |

  % Turn off collision avoidance
  \once \override TextScript.outside-staff-priority = ##f
  \textLengthOn        % and turn on textLengthOn
  c,,2^"Long Text   "  % Spaces at end are honored
  c''2 |
}

---

[ << Tweaking output ]	[首页][目录][索引]	[ Templates >> ]
[ < The textLengthOn command ]	[ 上 : Outside-staff objects ]	[ Grob sizing > ]

Dynamics placement

Dynamic markings will normally be positioned beneath the staff, but may be positioned above with the \dynamicUp command. They will be positioned vertically relative to the note to which they are attached, and will float below (or above) all within-staff objects such as phrasing slurs and bar numbers. This can give quite acceptable results, as this example shows:

\relative {
  \clef "bass"
  \key aes \major
  \time 9/8
  \dynamicUp
  bes4.~\f\< \( bes4 bes8 des4\ff\> c16 bes\! |
  ees,2.~\)\mf ees4 r8 |
}

However, if the notes and attached dynamics are close together the automatic placement will avoid collisions by displacing later dynamic markings further away, but this may not be the optimum placement, as this rather artificial example shows:

\dynamicUp
\relative { a'4\f b\mf a\mp b\p }

Should a similar situation arise in ‘real’ music, it may be preferable to space out the notes a little further, so the dynamic markings can all fit at the same vertical distance from the staff. We were able to do this for markup text by using the \textLengthOn command, but there is no equivalent command for dynamic marks. So we shall have to work out how to do this using \override commands.

---

[ << Tweaking output ]	[首页][目录][索引]	[ Templates >> ]
[ < Dynamics placement ]	[ 上 : Outside-staff objects ]	[ Vertical spacing > ]

Grob sizing

First we must learn how grobs are sized. All grobs have a reference point defined within them which is used to position them relative to their parent object. This point in the grob is then positioned at a horizontal distance, X-offset, and at a vertical distance, Y-offset, from its parent. The horizontal extent of the object is given by a pair of numbers, X-extent, which say where the left and right edges are relative to the reference point. The vertical extent is similarly defined by a pair of numbers, Y-extent. These are properties of all grobs which support the grob-interface.

By default, outside-staff objects are given a width of zero so that they may overlap in the horizontal direction. This is done by the trick of making the leftmost extent infinity and the rightmost extent minus infinity by setting the extra-spacing-width to '(+inf.0 . -inf.0). To ensure they do not overlap in the horizontal direction we must override this value of extra-spacing-width to give them a little extra spacing. The units are the space between two staff lines, so moving the left edge half a unit to the left and the right edge half a unit to the right should do it:

\override DynamicText.extra-spacing-width = #'(-0.5 . 0.5)

Let’s see if this works in our previous example:

\dynamicUp
% Extend width by 1 staff space
\override DynamicText.extra-spacing-width = #'(-0.5 . 0.5)
\relative { a'4\f b\mf a\mp b\p }

This looks better, but maybe we would prefer the dynamic marks to be aligned along the same baseline rather than going up and down with the notes. The property to do this is staff-padding which is covered in the section on collisions (see Collisions of objects).

---

[ << Tweaking output ]	[首页][目录][索引]	[ Templates >> ]
[ < Dynamics placement ]	[ 上 : Outside-staff objects ]	[ Vertical spacing > ]

<< 回到文档索引

LilyPond — 学习手册 v2.24.4 (稳定分支).