version that you are working on. See TRANSLATION for details.
@end ignore
-@c \version "2.11.38"
+@c \version "2.11.55"
@node Changing defaults
@chapter Changing defaults
+@strong{N.B. This Chapter is under heavy development at present.}
The purpose of LilyPond's design is to provide the finest output
quality as a default. Nevertheless, it may happen that you need to
@uref{http://@/lilypond@/.org/@/doc/@/stable/@/Documentation/@/user/@/lilypond@/-internals/,on@/-line},
but is also included with the LilyPond documentation package.
+@c TODO The following is at variance to what actually follows. Fix -td
+
There are four areas where the default settings may be changed:
@itemize
* Interpretation contexts::
* Explaining the Internals Reference::
* Modifying properties::
+* Useful concepts and properties::
* Common properties::
* Advanced tweaks::
-* old The \override command::
* Discussion of specific tweaks::
@end menu
@node Contexts explained
@subsection Contexts explained
->> > > - list of contexts: my *danger unmaintainable*
->> > > alarm just went off. I'm
+@ignore
+@c TODO Rethink and rewrite
+
+>> > > - list of contexts: my *danger unmaintainable*
+>> > > alarm just went off. I'm
I knew it would... And leaving out some of them is perfectly fine
with me.
should be there, and then we could simply list the remaining ones
without
further explanation and with links to the IR.
+@end ignore
+
+@c TODO Improve layout, order and consistency of wording -td
+
+@c TODO Add introduction which explains contexts in generality -td
+
+Contexts are arranged heirarchically:
+
+@menu
+* Score - the master of all contexts::
+* Top-level contexts - staff containers::
+* Intermediate-level contexts - staves::
+* Bottom-level contexts - voices::
+@end menu
+
+@node Score - the master of all contexts
+@unnumberedsubsubsec Score - the master of all contexts
+
+This is the top level notation context. No other context can
+contain a Score context. By default the Score context handles
+the administration of time signatures and makes sure that items
+such as clefs, time signatures, and key-signatures are aligned
+across staves.
+
+A Score context is instantiated implicitly when a
+@code{\score @{@dots{}@}} or @code{\layout @{@dots{}@}} block is
+processed, or explicitly when a @code{\new Score} command is
+executed.
+
+@node Top-level contexts - staff containers
+@unnumberedsubsubsec Top-level contexts - staff containers
+
+@strong{@emph{StaffGroup}}
+
+Groups staves while adding a bracket on the left side, grouping
+the staves together. The bar lines of the contained staves are
+connected vertically. StaffGroup only consists of a collection
+of staves, with a bracket in front and spanning bar lines.
+
+@strong{@emph{ChoirStaff}}
+
+Identical to StaffGroup except that the bar lines of the contained
+staves are not connected vertically.
+
+@strong{@emph{GrandStaff}}
+
+A group of staves, with a brace on the left side, grouping
+the staves together. The bar lines of the contained staves are
+connected vertically.
+
+@strong{@emph{PianoStaff}}
+
+TODO No longer correct? Check. -td
+
+Just like GrandStaff but with a forced distance between the
+staves, so cross staff beaming and slurring can be used.
+
+@strong{@emph{InnerStaffGroup}}
+
+TODO -td
+
+@strong{@emph{InnerChoirStaff}}
+
+TODO -td
+
+@node Intermediate-level contexts - staves
+@unnumberedsubsubsec Intermediate-level contexts - staves
+
+@strong{@emph{Staff}}
+
+Handles clefs, bar lines, keys, accidentals. It can contain
+Voice contexts.
+
+@strong{@emph{RhythmicStaff}}
+
+Like Staff but for printing rhythms. Pitches are ignored;
+the notes are printed on one line.
+
+@strong{@emph{TabStaff}}
+
+Context for generating tablature. By default lays the music
+expression out as a guitar tablature, printed on six lines.
+
+@strong{@emph{DrumStaff}}
+
+Handles typesetting for percussion. Can contain DrumVoice
+
+@strong{@emph{VaticanaStaff}}
+
+Same as Staff, except that it is designed for typesetting
+a piece in gregorian style.
+
+@strong{@emph{MensuralStaff}}
+
+Same as Staff, except that it is designed for typesetting
+a piece in mensural style.
+
+@node Bottom-level contexts - voices
+@unnumberedsubsubsec Bottom-level contexts - voices
+
+Voice-level contexts initialise certain properties and start
+appropriate engravers. Being bottom-level contexts, they cannot
+contain other contexts.
+
+@strong{@emph{Voice}}
+
+Corresponds to a voice on a staff. This context handles the
+conversion of dynamic signs, stems, beams, super- and sub-scripts,
+slurs, ties, and rests. You have to instantiate this explicitly
+if you require multiple voices on the same staff.
+
+@strong{@emph{VaticanaVoice}}
+
+Same as Voice, except that it is designed for typesetting a piece
+in gregorian style.
+
+@strong{@emph{MensuralVoice}}
+
+Same as Voice, with modifications for typesetting a piece in
+mensural style.
+
+@strong{@emph{Lyrics}}
+
+Corresponds to a voice with lyrics. Handles the printing of a
+single line of lyrics.
+
+@strong{@emph{DrumVoice}}
+
+The voice context used in a percussion staff.
+
+@strong{@emph{FiguredBass}}
+
+The context in which BassFigure objects are created from
+input entered in @code{\figuremode} mode.
+
+@strong{@emph{TabVoice}}
+The voice context used within a TabStaff context. Usually left to
+be created implicitly.
-The Master Of All Contexts
-==========================
-
- * Score
- This is the top level notation context. No other context
-can
- contain a Score context. This context handles the
- administration of time signatures. It also makes sure that
- items such as clefs, time signatures, and key-signatures
-are
- aligned across staves.
- You cannot explicitly instantiate a Score context (since
-it is
- not contained in any other context). It is instantiated
- automatically when an output definition (a \score or
-\layout
- block) is processed.
- (it should also be made clear somewhere what the
-difference is between
- \score and \Score).
-
-Top-level contexts: Staff containers
-====================================
- * StaffGroup
- Groups staves while adding a bracket on the left side,
- grouping the staves together. The bar lines of the
-contained
- staves are connected vertically. StaffGroup only consists
-of a
- collection of staves, with a bracket in front and spanning
-bar
- lines.
- * ChoirStaff
- Identical to StaffGroup except that the contained staves
-are
- not connected vertically.
- * GrandStaff
- A group of staves, with a brace on the left side, grouping
-the
- staves together. The bar lines of the contained staves are
- connected vertically.
- * PianoStaff
- Just like GrandStaff but with a forced distance between
-the
- staves, so cross staff beaming and slurring can be used.
- * DrumStaff
- Handles typesetting for percussion. Can contain DrumVoice
- * InnerStaffGroup
- * InnerChoirStaff
-
-Staff-level contexts
-====================
- * Staff
- Handles clefs, bar lines, keys, accidentals. It can
-contain
- Voice contexts.
- * RhythmicStaff
- Like Staff but for printing rhythms. Pitches are
- ignored; the notes are printed on one line.
- * TabStaff
- Context for generating tablature. By default lays the
-music
- expression out as a guitar tablature, printed on six
-lines.
- * VaticanaStaff
- Same as Staff, except that it is accommodated for
- typesetting a piece in gregorian style.
- * MensuralStaff
- Same as Staff, except that it is accommodated for
- typesetting a piece in mensural style.
-
-Voice-level (bottom) contexts
-=============================
-What is generated by default here? The voice-level contexts
-initiate
-certain properties and start engravers.
-
- * Voice
- Corresponds to a voice on a staff. This context handles
-the
- conversion of dynamic signs, stems, beams, super- and
- subscripts, slurs, ties, and rests.
- You have to instantiate this explicitly if you want to
-have
- multiple voices on the same staff.
- Bottom context.
- * VaticanaVoice
- Same as Voice, except that it is accommodated for
- typesetting a piece in gregorian style.
- * MensuralVoice
- Same as Voice, except that it is accommodated for
- typesetting a piece in mensural style.
- * Lyrics
- Corresponds to a voice with lyrics. Handles the printing
-of a
- single line of lyrics.
- Bottom context.
- * DrumVoice
- A voice on a percussion staff.
- * FiguredBass
-
- * ChordNames
- Typesets chord names. This context is a `bottom' context;
-it
- cannot contain other contexts.
+@strong{@emph{ChordNames}}
+
+Typesets chord names.
------------------------------
+
+TODO
+
Then the following, which I don't know what to do with:
- * TabVoice
* GregorianTranscriptionVoice
* GregorianTranscriptionStaff
* FretBoards
Engraves fretboards from chords. Not easy... Not
documented.
+ There is now some documentation on FretBoards in the NR, under
+ instrument-specific notation -- cds.
+
* NoteNames
* CueVoice Not documented
context.
-
@node Creating contexts
@subsection Creating contexts
+@c TODO \new Score and \score
+@c TODO more complete descriptions rather than learning style
+
For scores with only one voice and one staff, contexts are
created automatically. For more complex scores, it is necessary to
create them by hand. There are three commands that do this.
@node Modifying context plug-ins
@subsection Modifying context plug-ins
+@c TODO Should this be Modifying engravers or Modifying contexts?
+
Notation contexts (like @code{Score} and @code{Staff}) not only
store properties,
they also contain plug-ins called @q{engravers} that create notation
@subsection Changing context default settings
The adjustments of the previous subsections (
-@ref{The \set command}, @ref{Modifying context plug-ins}, and
+@ref{The set command}, @ref{Modifying context plug-ins}, and
@ref{Overview of modifying properties}) can also be entered
separately from the music in the @code{\layout} block,
All these plug-ins have to cooperate, and this is achieved with a
special plug-in, which must be marked with the keyword @code{\type}.
-This should always be @rinternals{Engraver_group},
+This should always be @code{Engraver_group}.
@example
\type "Engraver_group"
could be useful in setting up a vocal staff (@rlearning{Vocal ensembles}) and
in ossia,
-FIXME: this section doesn't work in pdf. (?)
+@c TODO Better example needed. Ref LM, and expand on it.
@cindex ossia
@findex alignAboveContext
@node Navigating the program reference
@subsection Navigating the program reference
+@c TODO remove this (it's in the LM)
+@c Replace with more factual directions
+
Suppose we want to move the fingering indication in the fragment
below:
@c outdated info; probably will delete.
@ignore
This fragment points to two parts of the program reference: a page
-on @code{FingerEvent} and one on @code{Fingering}.
+on @code{FingeringEvent} and one on @code{Fingering}.
-The page on @code{FingerEvent} describes the properties of the music
+The page on @code{FingeringEvent} describes the properties of the music
expression for the input @code{-2}. The page contains many links
forward. For example, it says
This engraver creates the following layout objects: @rinternals{Fingering}.
@end quotation
-In other words, once the @code{FingerEvent}s are interpreted, the
+In other words, once the @code{FingeringEvent}s are interpreted, the
@code{Fingering_engraver} plug-in will process them.
@end ignore
The programmer's reference is available as an HTML document. It is
highly recommended that you read it in HTML form, either online or
by downloading the HTML documentation. This section will be much more
-difficult to understand if you are using the
+difficult to understand if you are using the
PDF manual.
@end ifnothtml
@item @rinternals{fingering-event}:
Music event type @code{fingering-event} is in Music expressions named
-@rinternals{FingerEvent}
+@rinternals{FingeringEvent}
@end itemize
This path goes against the flow of information in the program: it
@node Determining the grob property
@subsection Determining the grob property
+@c TODO remove this (it's in the LM)
+@c Replace with more factual directions
+
Recall that we wanted to change the position of the @b{2} in
@lilypond[quote,fragment,relative=2,verbatim]
@subsection Naming conventions
Another thing that is needed, is an overview of the various naming
-conventions:
+conventions:
scheme functions: lowercase-with-hyphens (incl. one-word
names)
@menu
* Overview of modifying properties::
-* The \set command::
-* The \override command::
-* \set versus \override::
-* Objects connected to the input::
+* The set command::
+* The override command::
+* set versus override::
+* The tweak command::
@end menu
-@node The \set command
+@node The set command
@subsection The @code{\set} command
@cindex properties
-@node The \override command
+@node The override command
@subsection The @code{\override} command
Commands which change output generally look like
and the program reference.
-@node \set versus \override
+@node set versus override
@subsection @code{\set} vs. @code{\override}
We have seen two methods of changing properties: @code{\set} and
property (modified with @code{\set}) was created.
-@node Objects connected to the input
-@subsection Objects connected to the input
+@node The tweak command
+@subsection The @code{\tweak} command
TODO: can't use \tweak in a variable
details.
+@node Useful concepts and properties
+@section Useful concepts and properties
+
+
+@menu
+* Input modes::
+* Direction and placement::
+* Distances and measurements::
+* Spanners::
+@end menu
+
+@node Input modes
+@subsection Input modes
+
+The way in which the notation contained within an input file is
+interpreted is determined by the current input mode.
+
+@strong{Chord mode}
+
+This is activated with the @code{\chordmode} command, and causes
+input to be interpreted with the syntax of chord notation, see
+@ref{Chord notation}. Chords are rendered as notes on a staff.
+
+Chord mode is also activated with the @code{\chords} command.
+This also creates a new @code{ChordNames} context and
+causes the following input to be interpreted with the syntax of
+chord notation and rendered as chord names in the @code{ChordNames}
+context, see @ref{Printing chord names}.
+
+@strong{Drum mode}
+
+This is activated with the @code{\drummode} command, and causes
+input to be interpreted with the syntax of drum notation, see
+@ref{Basic percussion notation}.
+
+Drum mode is also activated with the @code{\drums} command.
+This also creates a new @code{DrumStaff} context and causes the
+following input to be interpreted with the syntax of drum notation
+and rendered as drum symbols on a drum staff, see @ref{Basic
+percussion notation}.
+
+@strong{Figure mode}
+
+This is activated with the @code{\figuremode} command, and causes
+input to be interpreted with the syntax of figured bass, see
+@ref{Entering figured bass}.
+
+Figure mode is also activated with the @code{\figures} command.
+This also creates a new @code{FiguredBass} context and causes the
+following input to be interpreted with the figured bass syntax
+and rendered as figured bass symbols in the @code{FiguredBass}
+context, see @ref{Introduction to figured bass}.
+
+@strong{Fret and tab modes}
+
+There are no special input modes for entering fret and tab symbols.
+
+To create tab diagrams, enter notes or chords in note mode and
+render them in a @code{TabStaff} context, see
+@ref{Default tablatures}.
+
+To create fret diagrams above a staff, you have two choices.
+You can either use the @code{FretBoards} context (see
+@ref{Automatic fret diagrams} or you can enter them as a markup
+above the notes using the @code{\fret-diagram} command (see
+@ref{Fret diagram markups}).
+
+@strong{Lyrics mode}
+
+This is activated with the @code{\lyricmode} command, and causes
+input to be interpreted as lyric syllables with optional durations
+and associated lyric modifiers, see @ref{Vocal music}.
+
+Lyric mode is also activated with the @code{\addlyrics} command.
+This also creates a new @code{Lyrics} context and an implicit
+@code{\lyricsto} command which associates the following lyrics
+with the preceding music.
+
+@strong{Markup mode}
+
+This is activated with the @code{\markup} command, and causes
+input to be interpreted with the syntax of markup, see
+@ref{Text markup commands}.
+
+@c silly work-around for texinfo broken-ness
+@c (@strong{Note...} causes a spurious cross-reference in Info)
+@b{Note mode}
+
+This is the default mode or it may be activated with the
+@code{\notemode} command. Input is interpreted as pitches,
+durations, markup, etc and typeset as musical notation on a staff.
+
+It is not normally necessary to specify note mode explicitly, but
+it may be useful to do so in certain situations, for example if you
+are in lyric mode, chord mode or any other mode and want to insert
+something that only can be done with note mode syntax.
+
+For example, to indicate dynamic markings for the verses of a
+choral pieces it is necessary to enter note mode to interpret
+the markings:
+
+@lilypond[verbatim,relative=2,quote]
+{ c4 c4 c4 c4 }
+\addlyrics {
+ \notemode{\set stanza = \markup{ \dynamic f 1. } }
+ To be sung loudly
+}
+\addlyrics {
+ \notemode{\set stanza = \markup{ \dynamic p 2. } }
+ To be sung quietly
+}
+@end lilypond
+
+
+
+@node Direction and placement
+@subsection Direction and placement
+
+In typesetting music the direction and placement of many items is
+a matter of choice. For example, the stems of notes can
+be directed up or down; lyrics, dynamics, and other expressive
+marks may be placed above or below the staff; text may be aligned
+left, right or center; etc. Most of these choices may be left to
+be determined automatically by LilyPond, but in some cases it may
+be desirable to force a particular direction or placement.
+
+@strong{Default actions}
+
+By default some directions are always up or always down (e.g.
+dynamics or fermata), while other things can alternate between
+up or down based on the stem direction (like slurs or accents).
+
+@c TODO Add table showing these
+
+@strong{Context layout}
+
+Contexts are positioned in a system from top to bottom in the
+order in which they are encountered. Note, however, that a
+context will be created implicitly if a command is encountered
+when there is no suitable context available to contain it.
+
+@c TODO Add example ?
+
+The default order in which contexts are laid out can be changed,
+see @ref{Aligning contexts}
+
+@strong{Articulation direction indicators}
+
+When adding articulations to notes the direction indicator,
+@code{^} (meaning @qq{up}), @code{_} (meaning @qq{down}) or
+@code{-} (meaning @qq{use default direction}), can usually be
+omitted, in which case @code{-} is assumed. But a direction
+indicator is @strong{always} required before
+
+@itemize
+@item @code{\tweak} commands
+@item @code{\markup} commands
+@item @code{\tag} commands
+@item string markups, e.g. -"string"
+@item fingering instructions, e.g. @code{-1}
+@item articulation shortcuts, e.g. @code{-.}, @code{->}, @code{--}
+@end itemize
+
+@strong{The direction property}
+
+The position or direction of many layout objects is controlled
+by the @code{direction} property.
+
+The value of the @code{direction} property may be
+set to @code{1}, meaning @qq{up} or @qq{above}, or to @code{-1},
+meaning @qq{down} or @qq{below}. The symbols @code{UP} and
+@code{DOWN} may be used instead of @code{1} and @code{-1}
+respectively. The default direction may be specified by setting
+@code{direction} to @code{0} or @code{CENTER}. Alternatively,
+in many cases predefined commands
+exist to specify the direction. These are all of the form
+
+@noindent
+@code{\xxxUp}, @code{xxxDown}, @code{xxxNeutral}
+
+@noindent
+where @code{xxxNeutral} means @qq{use the default direction}.
+See @rlearning{Within-staff objects}.
+
+In a few cases, arpeggio being the only common example, the value
+of the @code{direction} property specifies whether the object
+is to be placed to the right or left of the parent object. In
+this case @code{-1} or @code{LEFT} means @qq{to the left} and
+@code{1} or @code{RIGHT} means @qq{to the right}. @code{0}
+or @code{CENTER} means @qq{use the default} direction, as before.
+
+@ignore
+These all have side-axis set to #X
+AmbitusAccidental - direction has no effect
+Arpeggio - works
+StanzaNumber - not tried
+TrillPitchAccidental - not tried
+TrillPitchGroup - not tried
+@end ignore
+
+
+
+@node Distances and measurements
+@subsection Distances and measurements
+
+DISCUSS after working on other sections.
+
+TODO: staff spaces. Maybe move into tweaks?
+
+
+@node Spanners
+@subsection Spanners
+
+Many objects of musical notation extend over several notes or even
+several bars. Examples are crescendi, trills, tuplet brackets, and
+volta repeat brackets. Such objects are called @qq{spanners}, and
+have special properties to control their appearance and behaviour.
+Some of these properties are common to all spanners; others are
+restricted to a sub-set of the spanners.
@node Common properties
@section Common properties
@node Controlling visibility of objects
@subsection Controlling visibility of objects
+@cindex objects, visibility of
+@cindex grobs, visibility of
+@cindex visibility of objects
+
+There are four main ways in which the visibility of layout objects
+can be controlled: their stencil can be removed, they can be made
+transparent, they can be colored white, or their
+@code{break-visibility} property can be overridden. The first
+three apply to all layout objects; the last to just a few -- the
+@emph{breakable} objects. The Learning Manual introduces these
+four techniques, see @rlearning{Visibility and color of objects}.
+
+There are also a few other techniques which are specific to
+certain layout objects. These are covered under Special
+considerations.
+
+@menu
+* Removing the stencil::
+* Making objects transparent::
+* Painting objects white::
+* Using break-visibility::
+* Special considerations::
+@end menu
+
+
+@node Removing the stencil
+@unnumberedsubsubsec Removing the stencil
+
+@cindex stencil, removing
+
+Every layout object has a stencil property. By default this is set
+to the specific function which draws that object. If this property
+is overridden to @code{#f} no function will be called and the object
+will not be drawn. The default action can be recovered with
+@code{\revert}.
+
+@lilypond[quote,verbatim,relative=1]
+a1 a
+\override Score.BarLine #'stencil = ##f
+a a
+\revert Score.BarLine #'stencil
+a a a
+@end lilypond
+
+@node Making objects transparent
+@unnumberedsubsubsec Making objects transparent
+
+@cindex transparent, making objects
+
+Every layout object has a transparent property which by default is
+set to @code{#f}. If set to @code{#t} the object still occupies
+space but is made invisible.
+
+@lilypond[quote,verbatim,relative=2]
+a4 a
+\once \override NoteHead #'transparent = ##t
+a a
+@end lilypond
+
+@node Painting objects white
+@unnumberedsubsubsec Painting objects white
+
+@cindex objects, coloring
+@cindex coloring objects
+@cindex layers
+@cindex printing order
+@cindex overwriting objects
+@cindex objects, overwriting
+@cindex grobs, overwriting
+
+Every layout object has a color property which by default is set
+to @code{black}. If this is overridden to @code{white} the object
+will be indistinguishable from the white background. However,
+if the object crosses other objects the color of the crossing
+points will be determined by the order in which they are drawn,
+and this may leave a ghostly image of the white object, as shown
+here:
+
+@lilypond[quote,verbatim,relative=2]
+\override Staff.Clef #'color = #white
+a1
+@end lilypond
+
+This may be avoided by changing the order of printing the objects.
+All layout objects have a @code{layer} property which should be set
+to an integer. Objects with the lowest value of @code{layer} are
+drawn first, then objects with progressively higher values are drawn,
+so objects with higher values overwrite objects with lower values.
+By default most objects are assigned a @code{layer} value of
+@code{1}, although a few objects, including @code{StaffSymbol} and
+@code{BarLine}, are assigned a value of @code{0}. The order of
+printing objects with the same value of @code{layer} is indeterminate.
+
+In the example above the white clef, with a default @code{layer}
+value of @code{1}, is drawn after the staff lines (default
+@code{layer} value @code{0}), so overwriting them. To change this,
+the @code{Clef} object must be given in a lower value of
+@code{layer}, say @code{-1}, so that it is drawn earlier:
+
+@lilypond[quote,verbatim,relative=2]
+\override Staff.Clef #'color = #white
+\override Staff.Clef #'layer = #-1
+a1
+@end lilypond
+
+@node Using break-visibility
+@unnumberedsubsubsec Using break-visibility
+
+@c TODO Add making other objects breakable
+
+@cindex break-visibility
+
+Most layout objects are printed only once, but some like
+bar lines, clefs, time signatures and key signatures, may need
+to be printed twice when a line break occurs -- once at the end
+of the line and again at the start of the next line. Such
+objects are called @emph{breakable}, and have a property, the
+@code{break-visibility} property to control their visibility
+at the three positions in which they may appear -- at the
+start of a line, within a line if they are changed, and at the
+end of a line if a change takes place there.
+
+For example, the time signature
+by default will be printed at the start of the first line, but
+nowhere else unless it changes, when it will be printed at the
+point at which the change occurs. If this change occurs at the
+end of a line the new time signature will be printed at the start
+of the next line and a cautionary time signature will be printed
+at the end of the previous line as well.
+
+This behaviour is controlled by the @code{break-visibility}
+property, which is explained in
+@c Leave this ref on a newline - formats incorrectly otherwise -td
+@rlearning{Visibility and color of objects}. This property takes
+a vector of three booleans which, in order, determine whether the
+object is printed at the end of, within the body of, or at the
+beginning of a line. Or to be more precise, before a line break,
+where there is no line break, or after a line break.
+
+Alternatively, seven of the eight combinations may be specified
+by pre-defined functions, defined in @file{scm/output-lib.scm},
+where the last three columns indicate whether the layout objects
+will be visible in the positions shown at the head of the columns:
+
+@multitable @columnfractions .40 .15 .1 .1 .1
+@c TODO check these more carefully
+@headitem Function @tab Vector @tab Before @tab At no @tab After
+@headitem form @tab form @tab break @tab break @tab break
+
+@item @code{all-invisible} @tab @code{'#(#f #f #f)} @ @ @tab no @tab no @tab no
+@item @code{begin-of-line-visible} @tab @code{'#(#f #f #t)} @tab no @tab no @tab yes
+@item @code{end-of-line-visible} @tab @code{'#(#t #f #f)} @tab yes @tab no @tab no
+@item @code{all-visible} @tab @code{'#(#t #t #t)} @tab yes @tab yes @tab yes
+@c The center-visible function is not defined
+@c @item @code{center-visible} @tab @code{'#(#f #t #f)} @tab no @tab yes @tab no
+@item @code{begin-of-line-invisible} @tab @code{'#(#t #t #f)} @tab yes @tab yes @tab no
+@item @code{end-of-line-invisible} @tab @code{'#(#f #t #t)} @tab no @tab yes @tab yes
+@item @code{center-invisible} @tab @code{'#(#t #f #t)} @tab yes @tab no @tab yes
+@end multitable
+
+The @code{center-visible} function is not pre-defined.
+
+The default settings of @code{break-visibility} depend on the
+layout object. The following table shows all the layout objects
+of interest which are affected by @code{break-visibility} and the
+default setting of this property:
+
+@multitable @columnfractions .3 .3 .4
+
+@headitem Layout object @tab Usual context @tab Default setting
+
+@c omit Ambitus as it appears not to be affected by break-visibility -td
+@c @item @code{Ambitus} @tab as specified @tab @code{begin-of-line-visible}
+@item @code{BarLine} @tab @code{Score} @tab calculated
+@item @code{BarNumber} @tab @code{Score} @tab @code{begin-of-line-visible}
+@c omit the following item until it can be explained -td
+@c @item @code{BreakAlignGroup} @tab @code{Score} @tab calculated
+@item @code{BreathingSign} @tab @code{Voice} @tab @code{begin-of-line-invisible}
+@item @code{Clef} @tab @code{Staff} @tab @code{begin-of-line-visible}
+@item @code{Custos} @tab @code{Staff} @tab @code{end-of-line-visible}
+@item @code{DoublePercentRepeat} @tab @code{Voice} @tab @code{begin-of-line-invisible}
+@c omit KeyCancellation until it can be explained -td
+@c @item @code{KeyCancellation} @tab ?? @tab @code{begin-of-line-invisible}
+@item @code{KeySignature} @tab @code{Staff} @tab @code{begin-of-line-visible}
+@c omit LeftEdge until it can be explained -td
+@c @item @code{LeftEdge} @tab @code{Score} @tab @code{center-invisible}
+@item @code{OctavateEight} @tab @code{Staff} @tab @code{begin-of-line-visible}
+@item @code{RehearsalMark} @tab @code{Score} @tab @code{end-of-line-invisible}
+@item @code{TimeSignature} @tab @code{Staff} @tab @code{all-visible}
+
+@end multitable
+
+The example below shows the use of the vector form to control the
+visibility of barlines:
+
+@lilypond[quote,verbatim,relative=1,ragged-right]
+f4 g a b
+f4 g a b
+% Remove bar line at the end of the current line
+\once \override Score.BarLine #'break-visibility = #'#(#f #t #t)
+\break
+f4 g a b
+f4 g a b
+@end lilypond
+
+Although all three components of the vector used to override
+@code{break-visibility} must be present, not all of them are
+effective with every layout object, and some combinations may
+even give errors. The following limitations apply:
+
+@itemize @bullet
+@item Bar lines cannot be printed at start of line.
+@item A bar number cannot be printed at the start of the first
+line unless it is set to be different from 1.
+@item Clef -- see below
+@item Double percent repeats are either all printed or all
+suppressed. Use begin-of line-invisible to print and
+all-invisible to suppress.
+@item Key signature -- see below
+@item OctavateEight -- see below
+@end itemize
+
+@node Special considerations
+@unnumberedsubsubsec Special considerations
+
+@strong{@emph{Visibility following explicit changes}}
+
+@cindex key signature, visibility following explicit change
+@cindex explicitKeySignatureVisibility
+@cindex clef, visibility following explicit change
+@cindex explicitClefVisibility
+
+The @code{break-visibility} property controls the visibility of
+key signatures and changes of clef only at the start of lines,
+i.e. after a break. It has no effect on the visibility of the
+key signature or clef following an explicit key change or an
+explicit clef change within or at the end of a line. In the
+following example the key signature following the explicit change
+to B-flat major is still visible, even though @code{all-invisible}
+is set.
+
+@lilypond[quote,verbatim,relative=1,ragged-right]
+\key g \major
+f4 g a b
+% Try to remove all key signatures
+\override Staff.KeySignature #'break-visibility = #all-invisible
+\key bes \major
+f4 g a b
+\break
+f4 g a b
+f4 g a b
+@end lilypond
+
+The visibility of such explicit key signature and clef changes is
+controlled by the @code{explicitKeySignatureVisibility} and
+@code{explicitClefVisibility} properties. These are the equivalent
+of the @code{break-visibility} property and both take a vector of
+three booleans or the predefined functions listed above, exactly like
+@code{break-visibility}. Both are properties of the Staff context,
+not the layout objects themselves, and so they are set using the
+@code{\set} command. Both are set by default to @code{all-visible}.
+These properties control only the visibility of key signatures and
+clefs resulting from explicit changes and do not affect key
+signatures and clefs at the beginning of lines;
+@code{break-visibility} must still be overridden in the appropriate
+object to remove these.
+
+@lilypond[quote,verbatim,relative=1,ragged-right]
+\key g \major
+f4 g a b
+\set Staff.explicitKeySignatureVisibility = #all-invisible
+\override Staff.KeySignature #'break-visibility = #all-invisible
+\key bes \major
+f4 g a b \break
+f4 g a b
+f4 g a b
+@end lilypond
+
+@strong{@emph{Visibility of cautionary accidentals}}
+
+To remove the cautionary accidentals printed at an explicit key
+change, set the Staff context property @code{printKeyCancellation}
+to @code{#f}:
+
+@lilypond[quote,verbatim,relative=1,ragged-right]
+\key g \major
+f4 g a b
+\set Staff.explicitKeySignatureVisibility = #all-invisible
+\set Staff.printKeyCancellation = ##f
+\override Staff.KeySignature #'break-visibility = #all-invisible
+\key bes \major
+f4 g a b \break
+f4 g a b
+f4 g a b
+@end lilypond
+
+With these overrides only the accidentals before the notes remain
+to indicate the change of key.
+
+@c TODO Add visibility of cautionary accidentals before notes
+
+@strong{@emph{Automatic bars}}
+
+@cindex automaticBars
+@cindex bar lines, suppressing
+
+As a special case, the printing of bar lines can also be turned off
+by setting the @code{automaticBars} property in the Score context.
+If set to @code{#f}, bar lines will not be printed automatically;
+they must be explicitly created with a @code{\bar} command. Unlike
+the @code{\cadenzaOn} predefined command, measures are still counted.
+Bar generation will resume according to that count if this property
+is later set to @code{#t}. When set to @code{#f}, line breaks can
+occur only at explicit @code{\bar} commands.
+
+@c TODO Add example
+
+@strong{@emph{Octavated clefs}}
+
+@cindex octavated clefs, visibility of
+@cindex visibility of octavated clefs
+@cindex clefs, visibility of octavation
+
+The small octavation symbol on octavated clefs is produced by the
+@code{OctavateEight} layout object. Its visibility is controlled
+independently from that of the @code{Clef} object, so it is
+necessary to apply any required @code{break-visibility} overrides
+to both the @code{Clef} and the @code{OctavateEight} layout objects
+to fully suppress such clef symbols at the start of each line.
+
+For explicit clef changes, the @code{explicitClefVisibility}
+property controls both the clef symbol and any octavation symbol
+associated with it.
+
+
+@seealso
+Learning Manual:
+@rlearning{Visibility and color of objects}
+
@node Line styles
@subsection Line styles
The information that determines the end-points is computed
on-the-fly for every graphic object, but it is possible to
-override these.
+override these.
@lilypond[relative=2,ragged-right,verbatim,fragment]
e2 \glissando f
left side with @code{left} instead of @code{right}.
If @code{Y} is not set, the value is computed from the vertical
-position of right attachment point of the spanner.
+position of right attachment point of the spanner.
In case of a line break, the values for the span-points are
extended with contents of the @code{left-broken} and
@code{right-broken} sublists, for example
@lilypond[relative=2,ragged-right,verbatim,fragment]
-\override Glissando #'breakable = ##T
+\override Glissando #'breakable = ##T
\override Glissando #'bound-details #'right-broken #'Y = #-3
c1 \glissando \break
f1
@item X
This is the absolute coordinate of the end point. It is usually
-computed on the fly, and there is little use in overriding it.
+computed on the fly, and there is little use in overriding it.
@item stencil
Line spanners may have symbols at the beginning or end, which is
@end table
-FIXME: should this be in NR 3?
+@c TODO: Move to 5.4.4
The music function \endSpanners terminates spanners and hairpins
after exactly one note.
@node Rotating objects
@subsection Rotating objects
+Both layout objects and elements of markup text can be rotated by
+any angle about any point, but the method of doing so differs.
+
+@menu
+* Rotating layout objects::
+* Rotating markup::
+@end menu
+
+@node Rotating layout objects
+@unnumberedsubsubsec Rotating layout objects
+
+@cindex rotating objects
+@cindex objects, rotating
+
+All layout objects which support the @code{grob-interface} can be
+rotated by setting their @code{rotation} property. This takes a
+list of three items: the angle of rotation counter-clockwise,
+and the x and y coordinates of the point relative to the object's
+reference point about which the rotation is to be performed. The
+angle of rotation is specified in degrees and the coordinates in
+staff-spaces.
+
+The angle of rotation and the coordinates of the rotation point must
+be determined by trial and error.
+
+@cindex hairpins, angled
+@cindex angled hairpins
+
+There are only a few situations where the rotation of layout
+objects is useful; the following example shows one situation where
+they may be:
+
+@lilypond[quote,verbatim,relative=1]
+g4\< e' d' f\!
+\override Hairpin #'rotation = #'(20 -1 0)
+g,,4\< e' d' f\!
+@end lilypond
+
+@node Rotating markup
+@unnumberedsubsubsec Rotating markup
+
+All markup text can be rotated to lie at any angle by prefixing it
+with the @code{\rotate} command. The command takes two arguments:
+the angle of rotation in degrees counter-clockwise and the text to
+be rotated. The extents of the text are not rotated: they take
+their values from the extremes of the x and y coordinates of the
+rotated text. In the following example the
+@code{outside-staff-priority} property for text is set to @code{#f}
+to disable the automatic collision avoidance, which would push some
+of the text too high.
+
+@lilypond[quote,verbatim,relative=1]
+\override TextScript #'outside-staff-priority = ##f
+g4^\markup { \rotate #30 "a G" }
+b^\markup { \rotate #30 "a B" }
+des^\markup { \rotate #30 "a D-Flat" }
+fis^\markup { \rotate #30 "an F-Sharp" }
+@end lilypond
+
+
@node Aligning objects
@subsection Aligning objects
+@c FIXME Write this section
+
@node Advanced tweaks
@section Advanced tweaks
* Vertical grouping of grobs::
* Modifying ends of spanners::
* Modifying stencils::
+* Modifying shapes::
@end menu
@node Vertical grouping of grobs
@subsection Vertical grouping of grobs
+@c FIXME Expand this section
+
The VerticalAlignment and VerticalAxisGroup grobs work together.
VerticalAxisGroup groups together different grobs like Staff, Lyrics,
etc. VerticalAlignment then vertically aligns the different grobs
grouped together by VerticalAxisGroup. There is usually only one
VerticalAlignment per score but every Staff, Lyrics, etc. has its own
-VerticalAxisGroup.
+VerticalAxisGroup.
@node Modifying ends of spanners
@subsection Modifying ends of spanners
+@c FIXME Write this section
+@c See earlier material in Line styles
@node Modifying stencils
@subsection Modifying stencils
+All layout objects have a @code{stencil} property which is part of
+the @code{grob-interface}. By default, this property is usually
+set to a function specific to the object that is tailor-made to
+render the symbol which represents it in the output. For example,
+the standard setting for the @code{stencil} property of the
+@code{MultiMeasureRest} object is @code{ly:multi-measure-rest::print}.
+
+The standard symbol for any object can be replaced by modifying the
+@code{stencil} property to reference a different, specially-written,
+procedure. This requires a high level of knowledge of the internal
+workings of LilyPond, but there is an easier way which can often
+produce adequate results.
+
+This is to set the @code{stencil} property to the procedure which
+prints text -- @code{ly:text-interface::print} -- and to add a
+@code{text} property to the object which is set to contain the
+markup text which produces the required symbol. Due to the
+flexibility of markup, much can be achieved -- see in particular
+@ref{Graphic notation inside markup}.
+
+The following example demonstrates this by changing the note head
+symbol to a cross within a circle.
+
+@lilypond[verbatim,quote]
+XinO = {
+ \once \override NoteHead #'stencil = #ly:text-interface::print
+ \once \override NoteHead #'text = \markup {
+ \combine
+ \halign #-0.7 \draw-circle #0.85 #0.2 ##f
+ \musicglyph #"noteheads.s2cross"
+ }
+}
+\relative c'' {
+ a a \XinO a a
+}
+@end lilypond
+Any of the glyphs in the feta Font can be supplied to the
+@code{\musicglyph} markup command -- see @ref{The Feta font}.
-@node old The \override command
-@section old The @code{\override} command
+@c TODO Add inserting eps files or ref to later
-In the previous section, we have already touched on a command that
-changes layout details: the @code{\override} command. In this section,
-we will look in more detail at how to use the command in practice. The
-general syntax of this command is:
+@c TODO Add inserting Postscript or ref to later
-@example
-\override @var{context}.@var{layout_object} #'@var{layout_property} = #@var{value}
-@end example
+@seealso
+
+Notation Reference:
+@ref{Graphic notation inside markup},
+@ref{Formatting text},
+@ref{Text markup commands},
+@ref{The Feta font}.
-This will set the @var{layout_property} of the specified @var{layout_object},
-which is a member of the @var{context}, to the @var{value}.
+@node Modifying shapes
+@subsection Modifying shapes
+@menu
+* Modifying ties and slurs::
+@end menu
+
+@node Modifying ties and slurs
+@unnumberedsubsubsec Modifying ties and slurs
+
+Ties, slurs and phrasing slurs are drawn as third-order Bézier
+curves. If the shape of the tie or slur which is calculated
+automatically is not optimum, the shape may be modified manually by
+explicitly specifying the four control points required to define
+a third-order Bézier curve.
+
+Third-order or cubic Bézier curves are defined by four control
+points. The first and fourth control points are precisely the
+starting and ending points of the curve. The intermediate two
+control points define the shape. Animations showing how the curve
+is drawn can be found on the web, but the following description
+may be helpful. The curve starts from the first control point
+heading directly towards the second, gradually bending over to
+head towards the third and continuing to bend over to head towards
+the fourth, arriving there travelling directly from the third
+control point. The curve is entirely contained in the
+quadrilateral defined by the four control points.
+
+Here is an example of a case where the tie is not optimum, and
+where @code{\tieDown} would not help.
+
+@lilypond[verbatim,quote,relative=1]
+<<
+ { e1 ~ e }
+\\
+ { r4 <g c,> <g c,> <g c,> }
+>>
+@end lilypond
+
+One way of improving this tie is to manually modify its control
+points, as follows.
+
+The coordinates of the Bézier control points are specified in units
+of staff-spaces. The X@tie{}coordinate is relative to the reference
+point of the note to which the tie or slur is attached, and the
+Y@tie{}coordinate is relative to the staff center line. The
+coordinates are entered as a list of four pairs of decimal numbers
+(reals). One approach is to estimate the coordinates of the two
+end points, and then guess the two intermediate points. The optimum
+values are then found by trial and error.
+
+It is useful to remember that a symmetric curve requires symmetric
+control points, and that Bézier curves have the useful property that
+transformations of the curve such as translation, rotation and
+scaling can be achieved by applying the same transformation to the
+curve's control points.
+
+For the example above the following override gives a satisfactory
+tie:
+
+@lilypond[verbatim,quote,relative=1]
+<<
+ \once \override Tie
+ #'control-points = #'((1 . -1) (3 . 0.6) (12.5 . 0.6) (14.5 . -1))
+ { e1 ~ e1 }
+\\
+ { r4 <g c,> <g c,> <g c,>4 }
+>>
+@end lilypond
+
+@knownissues
+
+It is not possible to modify shapes of ties or slurs by changing
+the @code{control-points} property if there are more than one at
+the same musical moment, not even by using the @code{\tweak}
+command.
@node old Contexts explained
@subsection old Contexts explained
+@c FIXME Delete this section? It is in LM
+@c Or leave heading and go on from LM?
+
When music is printed, a lot of notational elements must be added to the
output. For example, compare the input and output of the following example:
projects / lilypond.git / blobdiff