@node Changing defaults
@chapter Changing defaults
-TODO: reorganise.
+
+The purpose of LilyPond's design is to provide the finest output
+quality as a default. Nevertheless, it may happen that you need to
+change this default layout. The layout is controlled through a large
+number of proverbial ``knobs and switches.'' This chapter does not
+list each and every knob. Rather, it outlines what groups of controls
+are available and explains how to lookup which knob to use for a
+certain effect.
+
+The controls available for tuning are described in a separate
+document, the @internalsref{Program reference} manual. That manual
+lists all different variables, functions and options available in
+LilyPond. It is written as a HTML document, which is available
+@uref{http://lilypond.org/doc/Documentation/user/out-www/lilypond-internals/,on-line},
+but is also included with the LilyPond documentation package.
+
+There are three areas where the default settings may be changed:
+
+@itemize @bullet
+@item Output: changing the appearance of individual
+ objects. For example, changing stem directions, or the location of
+ subscripts.
+
+@item Context: changing aspects of the translation from music events to
+ notation. For example, giving each staff a separate time signature.
+
+@item Global layout: changing the appearance of the spacing, line
+ breaks and page dimensions.
+@end itemize
+
+Then, there are separate systems for typesetting text (like
+@emph{ritardando}) and selecting different fonts. This chapter also
+discusses these.
+
+Internally, LilyPond uses Scheme (a LISP dialect) to provide
+infrastructure. Overriding layout decisions in effect accesses the
+program internals, so it is necessary to learn a (very small) subset
+of Scheme. That is why this chapter starts with a short tutorial on
+entering numbers, lists, strings and symbols in Scheme.
+
@menu
-* Scheme integration::
-* Setting variables::
-* Fine tuning layout::
+* Scheme tutorial::
+* File structure::
+* Interpretation contexts::
* Tuning output::
+* Fonts::
* Text markup::
* Global layout::
-* Interpretation context::
-* Output details::
@end menu
-
-
-@node Scheme integration
-@section Scheme integration
+@node Scheme tutorial
+@section Scheme tutorial
@cindex Scheme
@cindex GUILE
@cindex evaluating Scheme
@cindex LISP
-LilyPond internally uses GUILE, a Scheme-interpreter, to represent
-data throughout the whole program, and glue together different program
-modules. For advanced usage, it is sometimes necessary to access and
-program the Scheme interpreter.
+LilyPond uses the Scheme programming language, both as part of the
+input syntax, and as internal mechanism to glue together modules of
+the program. This section is a very brief overview of entering data in
+Scheme.@footnote{If you want to know more about Scheme, see
+@uref{http://www.schemers.org}.}
+
+The most basic thing of a language is data: numbers, character
+strings, lists, etc. Here is a list of data types that are relevant to
+LilyPond input.
+
+@table @asis
+@item Booleans
+ Boolean values are True or False. The Scheme for True is @code{#t}
+ and False is @code{#f}.
+@item Numbers
+ Numbers are entered in the standard fashion,
+ @code{1} is the (integer) number one, while @code{-1.5} is a
+ floating point number (a non-integer number).
+@item Strings
+ Strings are enclosed in double quotes,
+ @example
+ "this is a string"
+ @end example
+
+ Strings may span several lines
+ @example
+ "this
+ is
+ a string"
+ @end example
+
+ Quotation marks and newlines can also be added with so-called escape
+ sequences. The string @code{a said "b"} is entered as
+ @example
+ "a said \"b\""
+ @end example
+
+ Newlines and backslashes are escaped with @code{\n} and @code{\\}
+respectively.
+@end table
+
-Scheme is a full-blown programming language, from the LISP
-family. and a full discussion is outside the scope of this document.
-Interested readers are referred to the website
-@uref{http://www.schemers.org/} for more information on Scheme.
+In a music file, snippets of Scheme code are introduced with the hash
+mark @code{#}. So, the previous examples translated in LilyPond are
-The GUILE library for extension is documented at
-@uref{http://www.gnu.org/software/guile}.
-@ifinfo
-When it is installed, the following link should take you to its manual
-@ref{(guile.info)guile}
-@end ifinfo
+@example
+ ##t ##f
+ #1 #-1.5
+ #"this is a string"
+ #"this
+ is
+ a string"
+@end example
-@menu
-* Inline Scheme::
-@end menu
+For the rest of this section, we will assume that the data is entered
+in a music file, so we add @code{#}s everywhere.
+
+Scheme can be used to do calculations. It uses @emph{prefix}
+syntax. Adding 1 and 2 is written as @code{(+ 1 2)} rather than the
+traditional 1+2.
+
+@lisp
+ #(+ 1 2)
+ @result{} #3
+@end lisp
+
+The arrow @result{} shows that the result of evaluating @code{(+ 1 2)}
+is @code{3}. Calculations may be nested; the result of a function may
+be used for another calculation.
-@node Inline Scheme
-@subsection Inline Scheme
+@lisp
+ #(+ 1 (* 3 4))
+ @result{} #(+ 1 12)
+ @result{} #13
+@end lisp
+
+These calculations are examples of evaluations; an expression like
+@code{(* 3 4)} is replaced by its value @code{12}. A similar thing
+happens with variables. After defining a variable
-Scheme expressions can be entered in the input file by entering a
-hash-sign (@code{#}). The expression following the hash-sign is
-evaluated as Scheme. For example, the boolean value @var{true} is
-@code{#t} in Scheme, so for LilyPond @var{true} looks like @code{##t},
-and can be used in property assignments:
@example
- \set Staff.autoBeaming = ##f
+ twelve = #12
@end example
+variables can also be used in expressions, here
-@node Setting variables
-@section Setting variables
-
-When the music is converted from notes to print it is interpreted
-in left-to-right order. This is similar to what happens when we read
-music. During this step context-sensitive information such as the
-accidentals to print, and where bar lines must be placed, are stored in
-variables. These variables are called @emph{context properties}.
-The properties can also be manipulated from input files. Consider this input:
@example
-\set Staff.autoBeaming = ##f
+ twentyFour = #(* 2 twelve)
@end example
-@noindent
-It sets the property named @code{autoBeaming} in the current staff at
-this point in the music to @code{##f}, which means `false'. This
-property controls whether beams are printed automatically:
-@c
-@lilypond[relative=1,fragment,verbatim]
- c8 c c c
- \set Staff.autoBeaming = ##f
- c8 c c c
-@end lilypond
+the number 24 is stored in the variable @code{twentyFour}.
+
+The @emph{name} of a variable is also an expression, similar to a
+number or a string. It is entered as
-@noindent
-LilyPond includes a built-in programming language, namely, a dialect
-of Scheme. The argument to @code{\set}, @code{##f}, is an
-expression in that language. The first hash-mark signals that a piece
-of Scheme code follows. The second hash character is part of the
-boolean value true (@code{#t}). Values of other types may be
-entered as follows:
-@itemize @bullet
-@item a string, enclosed in double quotes, for example,
@example
- \set Staff.instrument = #"French Horn"
+ #'twentyFour
@end example
-@item a boolean: either @code{#t} or @code{#f}, for true and false
-respectively, e.g.
+
+The quote mark @code{'} prevents Scheme interpreter from substituting
+@code{24} for the @code{twentyFour}. Instead, we get the name
+@code{twentyFour}.
+
+This syntax will be used very frequently, since many of the layout
+tweaks involve assigning (Scheme) values to internal variables, for
+example
+
@example
- \set autoBeaming = ##f
- \set Score.skipBars = ##t
+ \override Stem #'thickness = #2.6
@end example
-@item a number, such as
+This instruction adjusts the appearance of stems. The value @code{2.6}
+is put into a the @code{thickness} variable of a @code{Stem}
+object. This makes stems almost twice as thick as their normal size.
+To distinguish between variables defined in input files (like
+@code{twentyFour} in the example above), and internal variables, we
+will call the latter ``properties.'' So, the stem object has a
+@code{thickness} property.
+
+Two-dimensional offsets (X and Y coordinates) as well as object sizes
+(intervals with a left and right point) are entered as @code{pairs}. A
+pair@footnote{In Scheme terminology, the pair is called @code{cons},
+and its two elements are called car and cdr respectively.} is entered
+as @code{(first . second)} and, like symbols, they must be quoted,
+
+@example
+ \override TextScript #'extra-offset = #'(1 . 2)
+@end example
+
+This assigns the pair (1, 2) to @code{extra-offset} variable of the
+TextScript object. This moves the object 1 staff space to the right,
+and 2 spaces up.
+
+The two elements of a pair may be arbitrary values, for example
+
@example
- \set Score.currentBarNumber = #20
+ #'(1 . 2)
+ #'(#t . #f)
+ #'("blah-blah" . 3.14159265)
@end example
-@item a symbol, which is introduced by a quote character, as in
+A list is entered by enclosing its elements in parentheses, and adding
+a quote. For example,
@example
- \set Staff.crescendoSpanner = #'dashed-line
+ #'(1 2 3)
+ #'(1 2 "string" #f)
@end example
-@item a pair, which is also introduced by a quote character, like in
-the following statements, which set properties to the pairs (-7.5, 6)
-and (3, 4) respectively:
+We have been using lists all along. A calculation, like @code{(+ 1
+2)} is also a list (containing the symbol @code{+} and the numbers 1
+and 2). Normally lists are interpreted as calculations, and the Scheme
+interpreter substitutes the outcome of the calculation. To enter a
+list, we stop evaluation. This is done by quoting the list with a
+quote @code{'} symbol. For calculations, do not use a quote.
+
+Inside a quoted list or pair, there is no need to quote anymore. The
+following is a pair of symbols, a list of symbols and a list of lists
+respectively,
@example
- \set Staff.minimumVerticalExtent = #'(-7.5 . 6)
- \set Staff.timeSignatureFraction = #'(3 . 4)
+ #'(stem . head)
+ #'(staff clef key-signature)
+ #'((1) (2))
@end example
-@item a list, which is also introduced by a quote character. In the
-following example, the @code{breakAlignOrder} property is set to a
-list of symbols:
+@node File structure
+@section File structure
+
+The following items may be present in a @file{.ly} file at toplevel
+
+@itemize @bullet
+@item An output definition, such as @code{\bookpaper}, @code{\midi}
+and @code{\paper}. Such a definition at toplevel changes the default
+settings for the block entered.
+
+@item An @code{\header} block. This sets the global header block. This
+is the block containing the definitions for book-wide settings, like
+composer, title, etc.
+
+@item An @code{\addquote} statement. See @ref{Quoting other voices}
+for more information.
+
+@item A @code{\score} block. This score will be collected with other
+toplevel scores, and combined as a single @code{\book}.
+
+This behavior can be changed by setting the variable
+@code{toplevel-score-handler} at toplevel. The default handler is
+defined in the init file @file{scm/lily.scm}.
+
+@item A @code{\book} block formats the block
+
+This behavior can be changed by setting the variable
+@code{toplevel-book-handler} at toplevel. The default handler is
+defined in the init file @file{scm/lily.scm}.
+
+
+@item A compound music expression, such as
@example
- \set Score.breakAlignOrder =
- #'(left-edge time-signature key-signatures)
+ @{ c'4 d' e'2 @}
@end example
-
+This will add the piece in a @code{\score}, and formats it into a
+single book together with all other toplevel @code{\score}s and music
+expressions.
+
+This behavior can be changed by setting the variable
+@code{toplevel-music-handler} at toplevel. The default handler is
+defined in the init file @file{scm/lily.scm}.
+
@end itemize
-There are many different properties. Not all of them are listed in
-this manual. However, the program reference lists them all in the
-section @internalsref{Context-properties}, and most properties are
-demonstrated in one of the
+The following example shows three things which may be entered at
+toplevel
+@verbatim
+ \paper {
+ % movements are non-justified by default
+ raggedright = ##t
+ }
+
+ \header {
+ title = "Do-re-mi"
+ }
+
+ { c'4 d' e2 }
+@end verbatim
+
+
+At any point in a file, any of the following lexical instructions can
+be entered:
+
+@itemize @bullet
+@item @code{\version}
+@item @code{\include}
+@item @code{\encoding}
+@item @code{\renameinput}
+@end itemize
+
+
+
+@node Interpretation contexts
+@section Interpretation contexts
+
+When music is printed, a lot of notation elements must be added to the
+input, which is often bare bones. For example, compare the input and
+output of the following example:
+
+@lilypond[verbatim,relative=2,fragment]
+ cis4 cis2. g4
+@end lilypond
+
+The input is rather sparse, but in the output, bar lines, accidentals,
+clef, and time signature are added. LilyPond @emph{interprets} the
+input. During this step, the musical information is inspected in time
+order, similar to reading a score from left to right. While reading,
+the program remembers where measure boundaries are, and what pitches
+need explicit accidentals. This information can be presented on
+several levels. For example, the effect of an accidental is limited
+to a single stave, while a bar line must be synchronized across the
+entire score.
+
+Within LilyPond, these rules and bits of information are grouped in
+so-called Contexts. Examples of context are @context{Voice},
+@context{Staff}, and @context{Score}. They are hierarchical, for
+example, a @context{Staff} can contain many @context{Voice}s, and a
+@context{Score} can contain many @context{Staff} contexts.
+
+Each context has the responsibility for enforcing some notation rules,
+creating some notation objects and maintaining the associated
+properties. So, the synchronization of bar lines is handled at
+@context{Score} context. The @context{Voice} may introduce an
+accidentals and then the @context{Staff} context maintains the rule to
+show or suppress the accidental for the remainder of the measure.
+
+For simple scores, contexts are created implicitly, and you need not
+be aware of them. For larger pieces, such as piano music, they must be
+created explicitly to make sure that you get as many staves as you
+need, and that they are in the correct order. For typesetting pieces
+with specialized notation, it can be useful to modify existing or
+define new contexts.
+
+
+Full description of all available contexts is in the program
+reference, see
@ifhtml
-@uref{../../../input/test/out-www/collated-files.html,tips-and-tricks}
+@internalsref{Contexts}.
@end ifhtml
-@ifnothtml
-tips-and-tricks
+@ifnothtml
+Translation @arrow{} Context.
@end ifnothtml
-examples.
+
+@c [TODO: describe propagation]
-@node Fine tuning layout
-@section Fine tuning layout
+@menu
+* Creating contexts::
+* Changing context properties on the fly::
+* Modifying context plug-ins::
+* Layout tunings within contexts::
+* Changing context default settings::
+* Defining new contexts::
+* Which properties to change::
+@end menu
-Sometimes it is necessary to change music layout by hand. When music
-is formatted, layout objects are created for each symbol. For
-example, every clef and every note head is represented by a layout
-object. These layout objects also carry variables, which we call
-@emph{layout properties}. By changing these variables from their
-values, we can alter the look of a formatted score:
+@node Creating contexts
+@subsection Creating contexts
-@lilypond[verbatim,relative]
- c4
- \override Stem #'thickness = #3.0
- c4 c4 c4
+For scores with only one voice and one staff, correct contexts are
+created automatically. For more complex scores, it is necessary to
+create them by hand. There are three commands which do this.
+
+The easiest command is @code{\new}, and it also the quickest to type.
+It is prepended to a music expression, for example
+
+@cindex @code{\new}
+@cindex new contexts
+@cindex Context, creating
+
+@example
+ \new @var{type} @var{music expression}
+@end example
+
+@noindent
+where @var{type} is a context name (like @code{Staff} or
+@code{Voice}). This command creates a new context, and starts
+interpreting @var{music expression} with that.
+
+A practical application of @code{\new} is a score with many
+staves. Each part that should be on its own staff, is preceded with
+@code{\new Staff}.
+
+@lilypond[verbatim,relative=2,raggedright,fragment]
+ << \new Staff { c4 c }
+ \new Staff { d4 d }
+ >>
@end lilypond
+@cindex @code{\context}
+
+Like @code{\new}, the @code{\context} command also directs a music
+expression to a context object, but gives the context an extra name. The
+syntax is
+
+@example
+ \context @var{type} = @var{id} @var{music}
+@end example
+
+This form will search for an existing context of type @var{type}
+called @var{id}. If that context does not exist yet, it is created.
+This is useful if the context is referred to later on. For example, when
+setting lyrics the melody is in a named context
+
+@example
+ \context Voice = "@b{tenor}" @var{music}
+@end example
+
+@noindent
+so the texts can be properly aligned to its notes,
+
+@example
+\new Lyrics \lyricsto "@b{tenor}" @var{lyrics}
+@end example
+
@noindent
-In the example shown here, the layout property @code{thickness} (a
-symbol) is set to 3 in the @code{Stem} layout objects of the current
-As a result, the notes following @code{\override} have thicker
-stems.
-For the most part, a manual override is needed only on a case by
-case basis and not for all subsequent instances of the altered
-property. To accomplish this, simply prefix @code{\once} to the
-@code{\override} statement and the override will apply only once,
-immediately reverting to its default setting, i.e.
+Another possibility is funneling two different music expressions into
+one context. In the following example, articulations and notes are
+entered separately,
+@verbatim
+music = \notes { c4 c4 }
+arts = \notes { s4-. s4-> }
+@end verbatim
+
+They are combined by sending both to the same @context{Voice} context,
+
+@verbatim
+ << \new Staff \context Voice = "A" \music
+ \context Voice = "A" \arts
+ >>
+@end verbatim
+@lilypond[raggedright]
+music = \notes { c4 c4 }
+arts = \notes { s4-. s4-> }
+\score {
+ \notes \relative c'' << \new Staff \context Voice = "A" \music
+ \context Voice = "A" \arts
+ >>
+}
+@end lilypond
+
+@cindex @code{\context}
+@cindex creating contexts
+
+The third command for creating contexts is
@example
- \once \override Stem #'thickness = #3.0
+ \context @var{type} @var{music}
@end example
-@lilypond[relative]
- c4
- \once \override Stem #'thickness = #3.0
- c4 c4 c4
+
+@noindent
+This is similar to @code{\context} with @code{= @var{id}}, but matches
+any context of type @var{type}, regardless of its given name.
+
+This variant is used with music expressions that can be interpreted at
+several levels. For example, the @code{\applyoutput} command (see
+@ref{Running a function on all layout objects}). Without an explicit
+@code{\context}, it is usually is applied to @context{Voice}
+
+@example
+ \applyoutput #@var{function} % apply to Voice
+@end example
+
+To have it interpreted at the @context{Score} or @context{Staff} level use
+these forms
+
+@example
+ \context Score \applyoutput #@var{function}
+ \context Staff \applyoutput #@var{function}
+@end example
+
+
+@node Changing context properties on the fly
+@subsection Changing context properties on the fly
+
+@cindex properties
+@cindex @code{\set}
+@cindex changing properties
+
+Each context can have different @emph{properties}, variables contained
+in that context. They can be changed during the interpretation step.
+This is achieved by inserting the @code{\set} command in the music,
+
+@quotation
+ @code{\set } @var{context}@code{.}@var{prop}@code{ = #}@var{value}
+@end quotation
+
+For example,
+@lilypond[verbatim,relative=2,fragment]
+ R1*2
+ \set Score.skipBars = ##t
+ R1*2
+@end lilypond
+
+This command skips measures that have no notes. The result is that
+multi rests are condensed. The value assigned is a Scheme object. In
+this case, it is @code{#t}, the boolean True value.
+
+If the @var{context} argument is left out, then the current bottom-most
+context (typically @context{ChordNames}, @context{Voice}, or
+@context{Lyrics}) is used. In this example,
+
+@lilypond[verbatim,relative=2,fragment]
+ c8 c c c
+ \set autoBeaming = ##f
+ c8 c c c
@end lilypond
@noindent
-Some overrides are so common that predefined commands are provided as
-a short cut. For example, @code{\slurUp} and @code{\stemDown}. These
-commands are described in
+the @var{context} argument to @code{\set} is left out, and the current
+@internalsref{Voice} is used.
+
+Contexts are hierarchical, so if a bigger context was specified, for
+example @context{Staff}, then the change would also apply to all
+@context{Voice}s in the current stave. The change is applied
+`on-the-fly', during the music, so that the setting only affects the
+second group of eighth notes.
+
+@cindex @code{\unset}
+
+There is also an @code{\unset} command,
+@quotation
+ @code{\set }@var{context}@code{.}@var{prop}
+@end quotation
+
+@noindent
+which removes the definition of @var{prop}. This command removes
+the definition only if it is set in @var{context}. In
+
+@example
+ \set Staff.autoBeaming = ##f
+ \unset Voice.autoBeaming
+@end example
+
+@noindent
+the current @context{Voice} does not have the property, and the
+definition at @context{Staff} level remains intact. Like @code{\set},
+the @var{context} argument does not have to be specified for a bottom
+context.
+
+Settings that should only apply to a single time-step can be entered
+easily with @code{\once}, for example in
+
+@lilypond[verbatim,relative=2,fragment]
+ c4
+ \once \set fontSize = #4.7
+ c4
+ c4
+@end lilypond
+
+the property @code{fontSize} is unset automatically after the second
+note.
+
+A full description of all available context properties is in the
+program reference, see
@ifhtml
-the
+@internalsref{Tunable-context-properties}.
@end ifhtml
-@ref{Notation manual}, under the sections for slurs and stems
-respectively.
+@ifnothtml
+Translation @arrow{} Tunable context properties.
+@end ifnothtml
-The exact tuning possibilities for each type of layout object are
-documented in the program reference of the respective
-object. However, many layout objects share properties, which can be
-used to apply generic tweaks. We mention a couple of these:
-@itemize @bullet
-@item The @code{extra-offset} property, which
-@cindex @code{extra-offset}
-has a pair of numbers as value, moves around objects in the printout.
-The first number controls left-right movement; a positive number will
-move the object to the right. The second number controls up-down
-movement; a positive number will move it higher. The units of these
-offsets are staff-spaces. The @code{extra-offset} property is a
-low-level feature: the formatting engine is completely oblivious to
-these offsets.
+@node Modifying context plug-ins
+@subsection Modifying context plug-ins
-In the following example, the second fingering is moved a little to
-the left, and 1.8 staff space downwards:
+Notation contexts (like Score and Staff) not only store properties,
+they also contain plug-ins, called ``engravers'' that create notation
+elements. For example, the Voice context contains a
+@code{Note_head_engraver} and the Staff context contains a
+@code{Key_signature_engraver}.
-@cindex setting object properties
+For a full a description of each plug-in, see
+@ifhtml
+@internalsref{Engravers}.
+@end ifhtml
+@ifnothtml
+Program reference @arrow Translation @arrow{} Engravers.
+@end ifnothtml
+Every context described in
+@ifhtml
+@internalsref{Contexts}
+@end ifhtml
+@ifnothtml
+Program reference @arrow Translation @arrow{} Context.
+@end ifnothtml
+lists the engravers used for that context.
-@lilypond[relative=1,verbatim]
-\stemUp
-f-5
-\once \override Fingering
- #'extra-offset = #'(-0.3 . -1.8)
-f-5
+
+It can be useful to shuffle around these plug-ins. This is done by
+starting a new context, with @code{\new} or @code{\context}, and
+modifying it like this,
+
+@example
+ \new @var{context} \with @{
+ \consists @dots{}
+ \consists @dots{}
+ \remove @dots{}
+ \remove @dots{}
+ @emph{etc.}
+ @}
+ @var{..music..}
+@end example
+
+where the @dots{} should be the name of an engraver. Here is a simple
+example which removes @code{Time_signature_engraver} and
+@code{Clef_engraver} from a @code{Staff} context,
+
+@lilypond[relative=1, verbatim,fragment]
+<< \new Staff {
+ f2 g
+ }
+ \new Staff \with {
+ \remove "Time_signature_engraver"
+ \remove "Clef_engraver"
+ } {
+ f2 g2
+ }
+>>
@end lilypond
-@item
-Setting the @code{transparent} property will cause an object to be printed
-in `invisible ink': the object is not printed, but all its other
-behavior is retained. The object still takes up space, it takes part in
-collisions, and slurs, and ties and beams can be attached to it.
+In the second stave there are no time signature or clef symbols. This
+is a rather crude method of making objects disappear since it will affect
+the entire staff. The spacing will be adversely influenced too. A more
+sophisticated methods of blanking objects is shown in @ref{Common
+tweaks}.
-@cindex transparent objects
-@cindex removing objects
-@cindex invisible objects
-The following example demonstrates how to connect different voices
-using ties. Normally, ties only connect two notes in the same
-voice. By introducing a tie in a different voice, and blanking a stem
-in that voice, the tie appears to cross voices:
+The next example shows a practical application. Bar lines and time
+signatures are normally synchronized across the score. This is done
+by the @code{Timing_engraver}. This plug-in keeps an administration of
+time signature, location within the measure, etc. By moving the
+@code{Timing_engraver} engraver from Score to Staff context, we can
+have a score where each staff has its own time signature.
-@lilypond[fragment,relative=1,verbatim]
- c4 << {
- \once \override Stem #'transparent = ##t
- b8~ b8
- } \\ {
- b[ g8]
- } >>
+@cindex polymetric scores
+
+
+@lilypond[relative=1,raggedright,verbatim,fragment]
+\new Score \with {
+ \remove "Timing_engraver"
+} <<
+ \new Staff \with {
+ \consists "Timing_engraver"
+ } {
+ \time 3/4
+ c4 c c c c c
+ }
+ \new Staff \with {
+ \consists "Timing_engraver"
+ } {
+ \time 2/4
+ c4 c c c c c
+ }
+>>
@end lilypond
-@item
-The @code{padding} property for objects with
-@cindex @code{padding}
-@code{side-position-interface} can be set to increase distance between
-symbols that are printed above or below notes. We only give an
-example; a more elaborate explanation is in @ref{Constructing a
-tweak}:
-@lilypond[relative=1,verbatim]
- c2\fermata
- \override Script #'padding = #3
- b2\fermata
+@node Layout tunings within contexts
+@subsection Layout tunings within contexts
+
+Each context is responsible for creating certain types of graphical
+objects. The settings used for printing these objects are also stored by
+context. By changing these settings, the appearance of objects can be
+altered.
+
+The syntax for this is
+
+@example
+ \override @var{context}.@var{name}@code{ #'}@var{property} = #@var{value}
+@end example
+
+Here @var{name} is the name of a graphical object, like @code{Stem} or
+@code{NoteHead}, and @var{property} is an internal variable of the
+formatting system (`grob property' or `layout property'). The latter is a
+symbol, so it must be quoted. The subsection @ref{Constructing a
+tweak} explains what to fill in for @var{name}, @var{property}, and
+@var{value}. Here we only discuss functionality of this command.
+
+The command
+
+@verbatim
+ \override Staff.Stem #'thickness = #4.0
+@end verbatim
+
+@noindent
+makes stems thicker (the default is 1.3, with staff line thickness as a
+unit). Since the command specifies @context{Staff} as context, it only
+applies to the current staff. Other staves will keep their normal
+appearance. Here we see the command in action:
+
+@lilypond[verbatim,relative=2,fragment]
+ c4
+ \override Staff.Stem #'thickness = #4.0
+ c4
+ c4
+ c4
@end lilypond
-@end itemize
+The @code{\override} command is executed during the interpreting phase,
+and changes the definition of the @code{Stem} within
+@context{Staff}. After the command all stems are thickened.
+
+Analogous to @code{\set}, the @var{context} argument may be left out,
+causing it to default to @context{Voice}, and adding @code{\once} applies
+the change during one timestep only
+
+@lilypond[fragment,verbatim,relative=2]
+ c4
+ \once \override Stem #'thickness = #4.0
+ c4
+ c4
+@end lilypond
+
+The @code{\override} must be done before the object is
+started. Therefore, when altering @emph{Spanner} objects, like slurs or
+beams, the @code{\override} command must be executed at the moment when
+the object is created. In this example,
-More specific overrides are also possible. The notation manual
-discusses in depth how to figure out these statements for yourself, in
-@ref{Tuning output}.
+@lilypond[fragment,verbatim,relative=2]
+ \override Slur #'thickness = #3.0
+ c8[( c
+ \override Beam #'thickness = #0.6
+ c8 c])
+@end lilypond
+
+@noindent
+the slur is fatter and the beam is not. This is because the command for
+@code{Beam} comes after the Beam is started. Therefore it has no effect.
+
+Analogous to @code{\unset}, the @code{\revert} command for a context
+undoes a @code{\override} command; like with @code{\unset}, it only
+affects settings that were made in the same context. In other words, the
+@code{\revert} in the next example does not do anything.
+
+@verbatim
+ \override Voice.Stem #'thickness = #4.0
+ \revert Staff.Stem #'thickness
+@end verbatim
+
+
+
+
+@seealso
+
+Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
+@internalsref{PropertySet}, @internalsref{All-backend-properties}, and
+@internalsref{All-layout-objects}.
+
+
+@refbugs
+
+The back-end is not very strict in type-checking object properties.
+Cyclic references in Scheme values for properties can cause hangs
+or crashes, or both.
+@node Changing context default settings
+@subsection Changing context default settings
+
+The adjustments of the previous chapters can also be entered separate
+from the music, in the @code{\paper} block,
+
+@example
+ \paper @{
+ @dots{}
+ \context @{
+ \Staff
+
+ \set fontSize = #-2
+ \override Stem #'thickness
+ \remove "Time_signature_engraver"
+ @}
+ @}
+@end example
+
+Here
+@example
+ \Staff
+@end example
+
+@noindent
+takes the existing definition @context{Staff} from the identifier
+@code{Staff}. This works analogously to other contexts.
+
+The statements
+@example
+ \set fontSize = #-2
+ \override Stem #'thickness
+ \remove "Time_signature_engraver"
+@end example
+
+@noindent
+affect all staves in the score.
+
+The @code{\set} keyword is optional within the @code{\paper} block, so
+
+@example
+ fontSize = #-2
+@end example
+
+@noindent
+will also work.
+
+
+
+@refbugs
+
+It is not possible to collect changes in a variable, and apply them to
+one @code{\context} definition by referring to that variable.
+
+
+@node Defining new contexts
+@subsection Defining new contexts
+
+Specific contexts, like @context{Staff} and @code{Voice}, are made of
+simple building blocks, and it is possible to compose engraver
+plug-ins in different combinations, thereby creating new types of
+contexts.
+
+The next example shows how to build a different type of
+@context{Voice} context from scratch. It will be similar to
+@code{Voice}, but print centered slash noteheads only. It can be used
+to indicate improvisation in Jazz pieces,
+
+@lilypond[raggedright]
+ \paper { \context {
+ \name ImproVoice
+ \type "Engraver_group_engraver"
+ \consists "Note_heads_engraver"
+ \consists "Text_engraver"
+ \consists Pitch_squash_engraver
+ squashedPosition = #0
+ \override NoteHead #'style = #'slash
+ \override Stem #'transparent = ##t
+ \alias Voice
+ }
+ \context { \Staff
+ \accepts "ImproVoice"
+ }}
+ \score { \notes \relative c'' {
+ a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
+ c4 c^"undress" c_"while playing :)" c }
+ a1
+ }}
+@end lilypond
+
+
+These settings are again done within a @code{\context} block inside a
+@code{\paper} block,
+
+@example
+ \paper @{
+ \context @{
+ @dots{}
+ @}
+ @}
+@end example
+
+In the following discussion, the example input shown should go on the
+@dots{} in the previous fragment.
+
+First, name the context gets a name. Instead of @context{Voice} it
+will be called @context{ImproVoice},
+
+@verbatim
+ \name ImproVoice
+@end verbatim
+
+Since it is similar to the @context{Voice}, we want commands that work
+on (existing) @context{Voice}s to remain working. This is achieved by
+giving the new context an alias @context{Voice},
+
+@verbatim
+ \alias Voice
+@end verbatim
+
+The context will print notes, and instructive texts
+
+@verbatim
+ \consists Note_heads_engraver
+ \consists Text_engraver
+@end verbatim
+
+but only on the center line,
+
+@verbatim
+ \consists Pitch_squash_engraver
+ squashedPosition = #0
+@end verbatim
+
+The @internalsref{Pitch_squash_engraver} modifies note heads (created
+by @internalsref{Note_heads_engraver}) and sets their vertical
+position to the value of @code{squashedPosition}, in this case
+@code{0}, the center line.
+
+The notes look like a slash, without a stem,
+
+@verbatim
+ \override NoteHead #'style = #'slash
+ \override Stem #'transparent = ##t
+@end verbatim
+
+
+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 @internalsref{Engraver_group_engraver},
+
+@example
+ \type "Engraver_group_engraver"
+@end example
+
+Putting together, we get
+
+@verbatim
+ \context {
+ \name ImproVoice
+ \type "Engraver_group_engraver"
+ \consists "Note_heads_engraver"
+ \consists "Text_script_engraver"
+ \consists Pitch_squash_engraver
+ squashedPosition = #0
+ \override NoteHead #'style = #'slash
+ \override Stem #'transparent = ##t
+ \alias Voice
+ }
+@end verbatim
+
+Contexts form hierarchies. We want to hang the @context{ImproVoice}
+under @context{Staff}, just like normal @code{Voice}s. Therefore, we
+modify the @code{Staff} definition with the @code{\accepts}
+command,@footnote{The opposite of @code{\accepts} is @code{\denies},
+which is sometimes when reusing existing context definitions. }
+
+
+
+@verbatim
+ \context {
+ \Staff
+ \accepts ImproVoice
+ }
+@end verbatim
+
+Putting both into a @code{\paper} block, like
+
+@example
+ \paper @{
+ \context @{
+ \name ImproVoice
+ @dots{}
+ @}
+ \context @{
+ \Staff
+ \accepts "ImproVoice"
+ @}
+@}
+@end example
+
+Then the output at the start of this subsection can be entered as
+
+@verbatim
+\score {
+ \notes \relative c'' {
+ a4 d8 bes8
+ \new ImproVoice {
+ c4^"ad lib" c
+ c4 c^"undress"
+ c c_"while playing :)"
+ }
+ a1
+ }
+}
+@end verbatim
+
+
+
+@node Which properties to change
+@subsection Which properties to change
+
+
+There are many different properties. Not all of them are listed in
+this manual. However, the program reference lists them all in the
+section @internalsref{Tunable-context-properties}, and most properties
+are demonstrated in one of the
+@ifhtml
+@uref{../../../../input/test/out-www/collated-files.html,tips-and-tricks}
+@end ifhtml
+@ifnothtml
+tips-and-tricks
+@end ifnothtml
+examples.
+
@node Tuning output
@section Tuning output
+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 at in more detail how to use the command in practice.
+First, we will give a a few versatile commands, which are sufficient
+for many situations. The next section will discuss general use of
+@code{\override}.
+
+@ignore
There are situations where default layout decisions are not
sufficient. In this section we discuss ways to override these
defaults.
Formatting is internally done by manipulating so called objects
(graphic objects). Each object carries with it a set of properties
-(object or layout properties) specific to that object. For example, a
-stem object has properties that specify its direction, length and
+(object or layout properties) specific to the object. For example, a
+stem object has properties that specify its direction, length, and
thickness.
-The most direct way of tuning the output is by altering the values of
-these properties. There are two ways of doing that: first, you can
+The most direct way of tuning the output is to alter the values of
+these properties. There are two ways of doing that: First, you can
temporarily change the definition of one type of object, thus
affecting a whole set of objects. Second, you can select one specific
object, and set a layout property in that object.
#'layout-property-name
@end example
+@end ignore
@menu
-* Tuning objects::
+* Common tweaks::
* Constructing a tweak::
-* Font selection::
+* Navigating the program reference::
+* Layout interfaces::
+* Determining the grob property::
@end menu
-@node Tuning objects
-@subsection Tuning objects
+@node Common tweaks
+@subsection Common tweaks
-@cindex object description
-
-The definition of an object is a list of default object
-properties. For example, the definition of the Stem object (available
-in @file{scm/define-grobs.scm}), includes the following definitions
-for @internalsref{Stem}:
-
-@example
- (thickness . 1.3)
- (beamed-lengths . (3.5 3.5 3.5 4.5 5.0))
- (Y-extent-callback . ,Stem::height)
- @var{...}
-@end example
+Some overrides are so common that predefined commands are provided as
+a short-cut, for example, @code{\slurUp} and @code{\stemDown}. These
+commands are described in
+@ifhtml
+the
+@end ifhtml
+@ref{Notation manual}, under the sections for slurs and stems
+respectively.
+The exact tuning possibilities for each type of layout object are
+documented in the program reference of the respective
+object. However, many layout objects share properties, which can be
+used to apply generic tweaks. We mention a few of these:
-Adding variables on top of this existing definition overrides the
-system default, and alters the resulting appearance of the layout
-object.
+@itemize @bullet
+@item The @code{extra-offset} property, which
+@cindex @code{extra-offset}
+has a pair of numbers as value, moves around objects in the printout.
+The first number controls left-right movement; a positive number will
+move the object to the right. The second number controls up-down
+movement; a positive number will move it higher. The units of these
+offsets are staff-spaces. The @code{extra-offset} property is a
+low-level feature: the formatting engine is completely oblivious to
+these offsets.
-@syntax
+In the following example, the second fingering is moved a little to
+the left, and 1.8 staff space downwards:
+@cindex setting object properties
-Changing a variable for only one object is commonly achieved with
-@code{\once}:
+@lilypond[fragment,relative=1,verbatim]
+\stemUp
+f-5
+\once \override Fingering
+ #'extra-offset = #'(-0.3 . -1.8)
+f-5
+@end lilypond
-@example
-\once \override @var{context}.@var{objectname}
- @var{symbol} = @var{value}
-@end example
-Here @var{symbol} is a Scheme expression of symbol type, @var{context}
-and @var{objectname} is a string and @var{value} is a Scheme expression.
-This command applies a setting only during one moment in the score.
+@item
+Setting the @code{transparent} property will cause an object to be printed
+in `invisible ink': the object is not printed, but all its other
+behavior is retained. The object still takes up space, it takes part in
+collisions, and slurs, and ties and beams can be attached to it.
-In the following example, only one @internalsref{Stem} object is
-changed from its original setting:
+@cindex transparent objects
+@cindex removing objects
+@cindex hiding objects
+@cindex invisible objects
+The following example demonstrates how to connect different voices
+using ties. Normally, ties only connect two notes in the same
+voice. By introducing a tie in a different voice,
-@lilypond[verbatim,fragment,relative=1]
- c4
- \once \override Voice.Stem #'thickness = #4
- c4
- c4
+@lilypond[fragment,relative=2]
+ << {
+ b8~ b8\noBeam
+ } \\ {
+ b[ g8]
+ } >>
@end lilypond
-@cindex @code{\once}
-For changing more objects, the same command, without @code{\once} can
-be used:
-@example
-\override @var{context}.@var{objectname} @var{symbol} = @var{value}
-@end example
-This command adds @code{@var{symbol} = @var{value}} to the definition
-of @var{objectname} in the context @var{context}, and this definition
-stays in place until it is removed.
-
-An existing definition may be removed by the following command:
-@c
-@example
-\property @var{context}.@var{objectname} \revert @var{symbol}
-@end example
-@c
+@noindent
+and blanking a stem in that voice, the tie appears to cross voices:
-Some examples:
-@lilypond[verbatim]
-c'4 \override Stem #'thickness = #4.0
-c'4
-c'4 \revert Stem #'thickness
-c'4
+@lilypond[fragment,relative=2,verbatim]
+ << {
+ \once \override Stem #'transparent = ##t
+ b8~ b8\noBeam
+ } \\ {
+ b[ g8]
+ } >>
@end lilypond
-The following example gives exactly the same result as the previous
-one (assuming the system default for stem thickness is 1.3):
-@c
-@lilypond[verbatim]
- c'4 \override Stem #'thickness = #4.0
- c'4
- c'4 \override Stem #'thickness = #1.3
- c'4
-@end lilypond
+@item
+The @code{padding} property for objects with
+@cindex @code{padding}
+@code{side-position-interface} can be set to increase distance between
+symbols that are printed above or below notes. We only give an
+example; a more elaborate explanation is in @ref{Constructing a
+tweak}:
-Reverting a setting which was not set in the first place has no
-effect.
+@lilypond[fragment,relative=1,verbatim]
+ c2\fermata
+ \override Script #'padding = #3
+ b2\fermata
+@end lilypond
+@end itemize
-@seealso
+More specific overrides are also possible. The next section
+discusses in depth how to figure out these statements for yourself.
-Internals: @internalsref{OverrideProperty}, @internalsref{RevertProperty},
-@internalsref{PropertySet}, @internalsref{All-backend-properties}, and
-@internalsref{All-layout-objects}.
+@node Constructing a tweak
+@subsection Constructing a tweak
-@refbugs
+The general procedure of changing output, that is, entering
+a command like
-The back-end is not very strict in type-checking object properties.
-Cyclic references in Scheme values for properties can cause hangs
-and/or crashes.
+@example
+ \override Voice.Stem #'thickness = #3.0
+@end example
-@menu
-* Constructing a tweak::
-* Applyoutput::
-* Font selection::
-* Text markup::
-@end menu
+@noindent
+means that we have to determine these bits of information:
-@node Constructing a tweak
-@subsection Constructing a tweak
+@itemize
+@item the context: here @context{Voice}.
+@item the layout object: here @code{Stem}.
+@item the layout property: here @code{thickness}
+@item a sensible value: here @code{3.0}
+@end itemize
@cindex internal documentation
@cindex @code{\set}
@cindex internal documentation
+We demonstrate how to glean this information from the notation manual
+and the program reference.
+The program reference is a set of HTML pages, which is part of the
+documentation package. On Unix systems, it is typically in
+@file{/usr/share/doc/lilypond}. If you have them, it is best to
+bookmark them in your webbrowser, because you will need them. They
+are also available on the web: go to the
+@uref{http://lilypond.org,LilyPond website}, click ``Documentation'',
+select the correct version, and then click ``Program reference.''
-Three pieces of information are required to use @code{\override} and
-@code{\set}: the name of the layout object, the context and the name
-of the property. We demonstrate how to glean this information from
-the notation manual and the generated documentation.
-
-The generated documentation is a set of HTML pages which should be
-included if you installed a binary distribution, typically in
-@file{/usr/share/doc/lilypond}. They are also available on the web:
-go to the @uref{http://lilypond.org,LilyPond website}, click
-``Documentation'', select the correct version, and click then
-``Program reference.'' It is advisable to bookmark the local HTML
-files. They will load faster than the ones on the web. If you use the
-version from the web, you must check whether the documentation matches
-the program version: it is generated from the definitions that the
-program uses, and therefore it is strongly tied to the LilyPond
-version.
-
+If you have them, use the local HTML files. They will load faster,
+and they are exactly matched to LilyPond version installed.
+
-@c [TODO: revise for new site.]
+@node Navigating the program reference
+@subsection Navigating the program reference
-Suppose we want to move the fingering indication in the fragment below:
+Suppose we want to move the fingering indication in the fragment
+below:
-@lilypond[relative=2,verbatim]
+@lilypond[fragment,relative=2,verbatim]
c-2
\stemUp
f
@quotation
@seealso
-Internals: @internalsref{FingerEvent} and @internalsref{Fingering}.
+Program reference: @internalsref{FingerEvent} and @internalsref{Fingering}.
@end quotation
-@separate
+This fragments points to two parts of the program reference: a page
+on @code{FingerEvent} and on @code{Fingering}.
+
+The page on @code{FingerEvent} describes the properties of the music
+expression for the input @code{-2}. The page contains many links
+forward. For example, it says
+
+@quotation
+ Accepted by: @internalsref{Fingering_engraver},
+@end quotation
@noindent
-In other words, the fingerings once entered, are internally stored as
-@code{FingerEvent} music objects. When printed, a @code{Fingering}
-layout object is created for every @code{FingerEvent}.
+That link brings us to the documentation for the Engraver, the
+plug-in, which says
+
+@quotation
+ This engraver creates the following layout objects: @internalsref{Fingering}.
+@end quotation
+
+In other words, once the @code{FingerEvent}s are interpreted, the
+@code{Fingering_engraver} plug-in will process them.
+The @code{Fingering_engraver} is also listed to create
+@internalsref{Fingering} objects,
+
-The Fingering object has a number of different functions, and each of
-those is captured in an interface. The interfaces are listed under
-@internalsref{Fingering} in the program reference.
+ Lo and behold, that is also the
+second bit of information listed under @b{See also} in the Notation
+manual. By clicking around in the program reference, we can follow the
+flow of information within the program, either forward (like we did
+here), or backwards, following links like this:
+@itemize @bullet
+
+@item @internalsref{Fingering}:
+ @internalsref{Fingering} objects are created by:
+ @b{@internalsref{Fingering_engraver}}
+
+@item @internalsref{Fingering_engraver}:
+Music types accepted: @b{@internalsref{fingering-event}}
+@item @internalsref{fingering-event}:
+Music event type @code{fingering-event} is in Music objects of type
+@b{@internalsref{FingerEvent}}
+@end itemize
+This path goes against the flow of information in the program: it
+starts from the output, and ends at the input event.
-The @code{Fingering} object has a fixed size
-(@internalsref{item-interface}), the symbol is a piece of text
-(@internalsref{text-interface}), whose font can be set
-(@internalsref{font-interface}). It is centered horizontally
-(@internalsref{self-alignment-interface}), it is placed next to other
-objects (@internalsref{side-position-interface}) vertically, and its
-placement is coordinated with other scripts
-(@internalsref{text-script-interface}). It also has the standard
-@internalsref{grob-interface} (grob stands for Graphical object)
+The program reference can also be browsed like a normal document. It
+contains a chapter on
+@ifhtml
+@internalsref{Music-definitions},
+@end ifhtml
+@ifnothtml
+Music definitions
+@end ifnothtml
+on @internalsref{Translation}, and the @internalsref{Backend}. Every
+chapter lists all the definitions used, and all properties that may be
+tuned.
+
+
+@node Layout interfaces
+@subsection Layout interfaces
+
+@internalsref{Fingering} is a layout object. Such an object is a
+symbol within the score. It has properties, which store numbers (like
+thicknesses and directions), but also pointers to related objects.
+A layout object is also called @emph{grob},
@cindex grob
-@cindex graphical object
-@cindex layout object
-@cindex object, layout
-with all the variables that come with
-it. Finally, it denotes a fingering instruction, so it has
-@internalsref{finger-interface}.
-
-For the vertical placement, we have to look under
-@code{side-position-interface}:
+which is short for Graphical Object.
+
+
+The page for @code{Fingering} lists the definitions for the
+@code{Fingering} object. For example, the page says
+
+@quotation
+ @code{padding} (dimension, in staff space):
+
+ @code{0.6}
+@end quotation
+
+which means that the number will be kept at a distance of at least 0.6
+of the note head.
+
+
+Each layout object may have several functions as a notational or
+typographical element. For example, the Fingering object
+has the following aspects
+
+@itemize @bullet
+@item Its size is independent of the horizontal spacing, unlike slurs or beams
+
+@item It is a piece of text. Granted, it's usually a very short text.
+
+@item That piece of text is typeset with a font, unlike slurs or beams.
+@item Horizontally, the center of the symbol should be aligned to the
+center of the notehead
+@item Vertically, the symbol is placed next to the note and the staff.
+
+@item The
+ vertical position is also coordinated with other super and subscript
+symbols
+@end itemize
+
+Each of these aspects is captured in a so-called @emph{interface},
+which are listed on the @internalsref{Fingering} page at the bottom
+
+@quotation
+This object supports the following interfaces:
+@internalsref{item-interface},
+@internalsref{self-alignment-interface},
+@internalsref{side-position-interface}, @internalsref{text-interface},
+@internalsref{text-script-interface}, @internalsref{font-interface},
+@internalsref{finger-interface}, and @internalsref{grob-interface}.
+@end quotation
+
+Clicking any of the links will take you to the page of the respective
+object interface. Each interface has a number of properties. Some of
+them are not user-serviceable (``Internal properties''), but others
+are.
+
+We have been talking of `the' @code{Fingering} object, but actually it
+does not amount to much. The initialization file
+@file{scm/define-grobs.scm} shows the soul of the `object',
+
+@verbatim
+ (Fingering
+ . (
+ (print-function . ,Text_item::print)
+ (padding . 0.6)
+ (staff-padding . 0.6)
+ (self-alignment-X . 0)
+ (self-alignment-Y . 0)
+ (script-priority . 100)
+ (font-encoding . number)
+ (font-size . -5)
+ (meta . ((interfaces . (finger-interface font-interface
+ text-script-interface text-interface
+ side-position-interface self-alignment-interface
+ item-interface))))
+ ))
+@end verbatim
+
+as you can see, @code{Fingering} is nothing more than a bunch of
+variable settings, and the webpage is directly generated from this
+definition.
+
+@node Determining the grob property
+@subsection Determining the grob property
+
+
+Recall that we wanted to change the position of the @b{2} in
+
+@lilypond[fragment,relative=2,verbatim]
+c-2
+\stemUp
+f
+@end lilypond
+
+Since the @b{2} is vertically positioned next to its note, we have to
+meddle with the interface associated with this positioning. This is
+done using @code{side-position-interface}. The page for this interface
+says
+
@quotation
@code{side-position-interface}
Position a victim object (this one) next to other objects (the
- support). In this case, the property @code{direction} signifies where to put the
+ support). The property @code{direction} signifies where to put the
victim object relative to the support (left or right, up or down?)
@end quotation
@item padding
(dimension, in staff space)
- add this much extra space between objects that are next to each
-other. Default value: @code{0.6}
+ add this much extra space between objects that are next to each
+ other.
@end table
@end quotation
fingering. The following command inserts 3 staff spaces of white
between the note and the fingering:
@example
-\once \override Fingering #'padding = #3
+\once \override Fingering #'padding = #3
@end example
Inserting this command before the Fingering object is created,
f
@end lilypond
-The context name @code{Voice} in the example above can be determined
-as follows. In the documentation for @internalsref{Fingering}, it says
-@quotation
-Fingering grobs are created by: @internalsref{Fingering_engraver} @c
-@end quotation
-Clicking @code{Fingering_engraver} shows the documentation of
-the module responsible for interpreting the fingering instructions and
-translating them to a @code{Fingering} object. Such a module is called
-an @emph{engraver}. The documentation of the @code{Fingering_engraver}
-says
-@example
-Fingering_engraver is part of contexts: Voice
-@end example
-so tuning the settings for Fingering should be done with
-@example
- \override Fingering @dots{}
-@end example
+In this case, the context for this tweak is @context{Voice}, which
+does not have to be specified for @code{\override}. This fact can
+also be deduced from the program reference, for the page for the
+@internalsref{Fingering_engraver} plug-in says
-Of course, the tweak may also done in a larger context than
-@code{Voice}, for example, @internalsref{Staff} or
-@internalsref{Score}.
+@quotation
+ Fingering_engraver is part of contexts: @dots{} @b{@internalsref{Voice}}
+@end quotation
-@seealso
-Internals: the program reference also contains alphabetical lists of
-@internalsref{Contexts}, @internalsref{All-layout-objects} and
-@internalsref{Music-expressions}, so you can also find which objects
-to tweak by browsing the internals document.
+@node Fonts
+@section Fonts
+@menu
+* Selecting font sizes::
+* Font selection::
+@end menu
-@node Font selection
-@subsection Font selection
+@node Selecting font sizes
+@subsection Selecting font sizes
The most common thing to change about the appearance of fonts is their
size. The font size of any context can be easily changed by setting
example is given below:
@c
@lilypond[fragment,relative=1,verbatim]
- c4 c4 \set fontSize = #-1
+ c4 c4 \set fontSize = #-3
f4 g4
@end lilypond
-This command will set @code{font-size} (see below), and does
-not change the size of variable symbols, such as beams or slurs.
+This command will set @code{font-size} (see below) in all layout
+objects in the current context. It does not change the size of
+variable symbols, such as beams or slurs.
+
+The font size is set by modifying the @code{font-size} property. Its
+value is a number indicating the size relative to the standard size.
+Each step up is an increase of approximately 12% of the font size. Six
+steps is exactly a factor two. The Scheme function @code{magstep}
+converts a @code{font-size} number to a scaling factor.
+
+LilyPond has fonts in different design sizes: the music fonts for
+smaller sizes are chubbier, while the text fonts are relatively wider.
+Font size changes are achieved by scaling the design size that is
+closest to the desired size.
+
+The @code{font-size} mechanism does not work for fonts selected
+through @code{font-name}. These may be scaled with
+@code{font-magnification}.
+
One of the uses of @code{fontSize} is to get smaller symbols for cue
notes. An elaborate example of those is in
@inputfileref{input/test,cue-notes.ly}.
-@cindex magnification
@cindex cue notes
+@cindex @code{font-style}
-The font used for printing a object can be selected by setting
-@code{font-name}, e.g.
-@example
- \override Staff.TimeSignature
- #'font-name = #"cmr17"
-@end example
+@refcommands
+
+The following commands set @code{fontSize} for the current voice:
+
+@cindex @code{\tiny}
+@code{\tiny},
+@cindex @code{\small}
+@code{\small},
+@cindex @code{\normalsize}
+@code{\normalsize}.
-@noindent
-Any font can be used, as long as it is available to @TeX{}. Possible
-fonts include foreign fonts or fonts that do not belong to the
-Computer Modern font family. The size of fonts selected in this way
-can be changed with the @code{font-magnification} property. For
-example, @code{2.0} blows up all letters by a factor 2 in both
-directions.
-@cindex font size
-@cindex font magnification
+
+@cindex magnification
+@cindex cue notes
+
+
+@node Font selection
+@subsection Font selection
Font selection for the standard fonts, @TeX{}'s Computer Modern fonts,
can also be adjusted with a more fine-grained mechanism. By setting
@code{font-interface}:
-@table @code
-@item font-family
+@itemize @bullet
+@item @code{font-encoding}
+is a symbol that sets layout of the glyphs. Choices include
+@code{text} for normal text, @code{braces} (for piano staff braces),
+@code{music} (the standard music font, including ancient glyphs),
+@code{dynamic} (for dynamic signs) and @code{number} for the number
+font.
+
+
+@item @code{font-family}
is a symbol indicating the general class of the typeface. Supported are
-@code{roman} (Computer Modern), @code{braces} (for piano staff
-braces), @code{music} (the standard music font, including ancient
-glyphs), @code{dynamic} (for dynamic signs) and @code{typewriter}.
+@code{roman} (Computer Modern), @code{sans}, and @code{typewriter}.
-@item font-shape
- is a symbol indicating the shape of the font, there are typically several
- font shapes available for each font family. Choices are @code{italic},
- @code{caps} and @code{upright}.
+@item @code{font-shape}
+ is a symbol indicating the shape of the font, there are typically
+several font shapes available for each font family. Choices are
+@code{italic}, @code{caps}, and @code{upright}.
-@item font-series
+@item @code{font-series}
is a symbol indicating the series of the font. There are typically several
font series for each font family and shape. Choices are @code{medium}
and @code{bold}.
-@end table
+@end itemize
+
+Fonts selected in the way sketched above come from a predefined style
+sheet.
-For any of these properties, the value @code{*} (i.e. the symbol
-@code{*}, entered as @code{#'*}), acts as a wildcard. This can be used
-to override default setting, which are always present. For example:
+ The font used for printing a object can be selected by setting
+@code{font-name}, e.g.
@example
- \override Lyrics .LyricText #'font-series = #'bold
- \override Lyrics .LyricText #'font-family = #'typewriter
- \override Lyrics .LyricText #'font-shape = #'*
+ \override Staff.TimeSignature
+ #'font-name = #"cmr17"
@end example
-@cindex @code{font-style}
-
-The font size is set by modifying the @code{font-size} property. Its
-value is a number indicating the size relative to the standard size.
-Each step up is an increase of approximately 12% of the font size. Six
-steps is exactly a factor two. The Scheme function @code{magstep}
-converts a @code{font-size} number to a scaling factor.
-
-LilyPond has fonts in different design sizes: the music fonts for
-smaller sizes are chubbier, while the text fonts are relatively wider.
-Font size changes are achieved by scaling the design size that is
-closest to the desired size.
-
-The @code{font-size} mechanism does not work for fonts selected
-through @code{font-name}. These may be scaled with
-@code{font-magnification}.
+@noindent
+Any font can be used, as long as it is available to @TeX{}. Possible
+fonts include foreign fonts or fonts that do not belong to the
+Computer Modern font family. The size of fonts selected in this way
+can be changed with the @code{font-magnification} property. For
+example, @code{2.0} blows up all letters by a factor 2 in both
+directions.
-@refcommands
+@cindex font size
+@cindex font magnification
-The following commands set @code{fontSize} for the current voice.
-@cindex @code{\tiny}
-@code{\tiny},
-@cindex @code{\small}
-@code{\small},
-@cindex @code{\normalsize}
-@code{\normalsize}.
@seealso
@refbugs
-There is no style sheet provided for other fonts besides the @TeX{}
+No style sheet is provided for other fonts besides the @TeX{}
Computer Modern family.
@cindex font selection
@cindex font switching
The markup in the example demonstrates font switching commands. The
-command @code{\bold} and @code{\italic} only apply to the first
-following word; enclose a set of texts with braces to apply a command
+command @code{\bold} and @code{\italic} apply to the first following
+word only; enclose a set of texts with braces to apply a command
to more words:
@example
\markup @{ \bold @{ hi there @} @}
In markup mode you can compose expressions, similar to mathematical
-expressions, XML documents and music expressions. The braces group
+expressions, XML documents, and music expressions. The braces group
notes into horizontal lines. Other types of lists also exist: you can
-stack expressions grouped with @code{<}, and @code{>} vertically with
+stack expressions grouped with @code{<} and @code{>} vertically with
the command @code{\column}. Similarly, @code{\center-align} aligns
texts by their center lines:
any effects of alignments applied to their markup arguments as a
whole. For example, the @internalsref{RehearsalMark} is horizontally
centered, so using @code{\mark \markup @{ \left-align .. @}} has no
-effect. Similarly, whole texts over notes cannot be moved vertically
-with @code{\raise}. For moving and aligning complete objects, grob
-properties should be used.
+effect.
+
+Similarly, for moving whole texts over notes with
+@code{\raise}, use the following trick:
+@example
+ "" \raise #0.5 raised
+@end example
+
+The text @code{raised} is now raised relative to the empty string
+@code{""} which is not visible. Alternatively, complete objects can
+be moved with layout properties such as @code{padding} and
+@code{extra-offset}.
Syntax errors for markup mode are confusing.
-Markup texts cannot be used in the titling of the @code{\header}
-field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
-for formatting.
+Markup texts cannot be used in the titling of the @code{\header}
+field. Titles are made by La@TeX{}, so La@TeX{} commands should be used
+for formatting.
+
+
+
+@menu
+* Overview of text markup commands::
+@end menu
+
+@node Overview of text markup commands
+@subsection Overview of text markup commands
+
+@include markup-commands.tely
+
+
+@node Global layout
+@section Global layout
+
+The global layout determined by three factors: the page layout, the
+line breaks, and the spacing. These all influence each other. The
+choice of spacing determines how densely each system of music is set,
+which influences where line breaks are chosen, and thus
+ultimately how many pages a piece of music takes. This section
+explains how to tune the algorithm for spacing.
+
+Globally spoken, this procedure happens in three steps: first,
+flexible distances (``springs'') are chosen, based on durations. All
+possible line breaking combination are tried, and the one with the
+best results --- a layout that has uniform density and requires as
+little stretching or cramping as possible --- is chosen.
+
+After spacing and linebreaking, the systems are distributed across
+pages, taking into account the size of the page, and the size of the
+titles.
+
+
+
+@menu
+* Setting global staff size::
+* Vertical spacing::
+* Horizontal spacing::
+* Line breaking::
+* Line length and line breaking::
+* Titling::
+* Page breaking::
+* Paper size::
+* Page layout::
+@end menu
+
+
+@node Setting global staff size
+@subsection Setting global staff size
+
+@cindex font size, setting
+@cindex staff size, setting
+@cindex @code{paper} file
+
+The Feta font provides musical symbols at eight different
+sizes. Each font is tuned for a different staff size: at a smaller size
+the font becomes heavier, to match the relatively heavier staff lines.
+The recommended font sizes are listed in the following table:
+
+@multitable @columnfractions .25 .25 .25 .25
+
+@item @b{font name}
+@tab @b{staff height (pt)}
+@tab @b{staff height (mm)}
+@tab @b{use}
+
+@item feta11
+@tab 11.22
+@tab 3.9
+@tab pocket scores
+
+@item feta13
+@tab 12.60
+@tab 4.4
+@tab
+
+@item feta14
+@tab 14.14
+@tab 5.0
+@tab
+
+@item feta16
+@tab 15.87
+@tab 5.6
+@tab
+
+@item feta18
+@tab 17.82
+@tab 6.3
+@tab song books
+@item feta20
+@tab 17.82
+@tab 7.0
+@tab standard parts
+@item feta23
+@tab 22.45
+@tab 7.9
+@tab
-@menu
-* Overview of text markup commands::
-@end menu
+@item feta26
+@tab 25.2
+@tab 8.9
+@tab
+@c modern rental material ?
-@node Overview of text markup commands
-@subsection Overview of text markup commands
+@end multitable
-@include markup-commands.tely
+These fonts are available in any sizes. The context property
+@code{fontSize} and the layout property @code{staff-space} (in
+@internalsref{StaffSymbol}) can be used to tune size for individual
+staves. The size of individual staves are relative to the global size,
+which can be set in the following manner:
+@example
+ #(set-global-staff-size 14)
+@end example
-@node Global layout
-@section Global layout
+This sets the global default size to 14pt staff height, and scales all
+fonts accordingly.
-The global layout determined by three factors: the page layout, the
-line breaks and the spacing. These all influence each other. The
-choice of spacing determines how densely each system of music is set,
-which influences where line breaks breaks are chosen, and thus
-ultimately how many pages a piece of music takes. This section
-explains how to tune the algorithm for spacing.
+@seealso
-Globally spoken, this procedure happens in three steps: first,
-flexible distances (``springs'') are chosen, based on durations. All
-possible line breaking combination are tried, and the one with the
-best results---a layout that has uniform density and requires as
-little stretching or cramping as possible---is chosen. When the score
-is processed by @TeX{}, each page is filled with systems, and page breaks
-are chosen whenever the page gets full.
+This manual: @ref{Selecting font sizes}.
@menu
* Vertical spacing::
* Horizontal spacing::
-* Font Size::
* Line breaking::
* Page layout::
@end menu
-
@node Vertical spacing
@subsection Vertical spacing
@example
\paper @{
\context @{
- \PianoStaffContext
+ \PianoStaff
\override VerticalAlignment #'forced-distance = #9
@}
@dots{}
duration adds a fixed amount (this amount is controlled by
@code{spacing-increment}) of space to the note.
-For example, the following piece contains lots of half, quarter and
+For example, the following piece contains lots of half, quarter, and
8th notes, the eighth note is followed by 1 note head width (NHW).
The quarter note is followed by 2 NHW, the half by 3 NHW, etc.
@lilypond[fragment,verbatim,relative=1] c2 c4. c8 c4. c8 c4. c8 c8
@cindex @code{stem-spacing-correction}
@cindex @code{spacing}
-In the introduction it was explained that stem directions influence
+In the Introduction it was explained that stem directions influence
spacing. This is controlled with @code{stem-spacing-correction}
property in @internalsref{NoteSpacing}, which are generated for every
@internalsref{Voice} context. The @code{StaffSpacing} object
\score { \notes {
c'4 e''4 e'4 b'4 |
b'4 e''4 b'4 e''4|
- \override Staff.NoteSpacing #'stem-spacing-correction
- = #1.5
- \override Staff.StaffSpacing #'stem-spacing-correction
- = #1.5
+ \override Staff.NoteSpacing #'stem-spacing-correction = #1.5
+ \override Staff.StaffSpacing #'stem-spacing-correction = #1.5
c'4 e''4 e'4 b'4 |
b'4 e''4 b'4 e''4|
}
created before any property commands are interpreted.
@example
\paper @{ \context @{
- \ScoreContext
- SpacingSpanner \override #'spacing-increment = #3.0
+ \Score
+ \override SpacingSpanner #'spacing-increment = #3.0
@} @}
@end example
score, the part containing the longer durations will be spaced too
widely.
-There is no convenient mechanism to manually override spacing.
-
-
-
-@node Font Size
-@subsection Font size
-@cindex font size, setting
-@cindex staff size, setting
-@cindex @code{paper} file
-
-The Feta font provides musical symbols at eight seven different
-sizes. Each font is tuned for a different staff size: at smaller sizes
-the font gets heavier, to match the relatively heavier staff lines.
-The recommended font sizes are listed in the following table:
-
-@multitable @columnfractions .25 .25 .25 .25
-
-@item @b{name}
-@tab @b{staff height (pt)}
-@tab @b{staff height (mm)}
-@tab @b{use}
-
-@item feta11
-@tab 11.22
-@tab 3.9
-@tab pocket scores
-
-@item feta13
-@tab 12.60pt
-@tab 4.4mm
-@tab
-
-@item feta14
-@tab 14.14pt
-@tab 5.0mm
-@tab
-
-@item feta16
-@tab 15.87pt
-@tab 5.6mm
-@tab
-
-@item feta18
-@tab 17.82pt
-@tab 6.3mm
-@tab song books
-
-@item feta20
-@tab 17.82pt
-@tab 7.0mm
-@tab standard parts
-
-@item feta23
-@tab 22.45 pt
-@tab 7.9mm
-@tab
-
-@item feta20
-@tab 25.2 pt
-@tab 8.9mm
-@tab
-@c modern rental material ?
-
-@end multitable
-
-These fonts are available in any sizes. The context property
-@code{fontSize} and the layout property @code{staff-space} (in
-@internalsref{StaffSymbol}) can be used to tune size for individual
-staves. The size of individual staves are relative to the global size,
-which can be set in the following manner:
-
+There is no convenient mechanism to manually override spacing. The
+following work-around may be used to insert extra space into a score.
@example
- #(set-global-staff-size 14)
+ \once \override Score.SeparationItem #'padding = #1
@end example
-This sets the global default size to 14pt staff height, and scales all
-fonts accordingly.
+No work-around exists for decreasing the amount of space.
+@menu
+* Line breaking::
+* Page layout::
+@end menu
@node Line breaking
@subsection Line breaking
@refcommands
-@code{\break}, @code{\noBreak}
+@code{\break}, and @code{\noBreak}.
@cindex @code{\break}
@cindex @code{\noBreak}
Internals: @internalsref{BreakEvent}.
-
-@node Page layout
-@subsection Page layout
+@node Line length and line breaking
+@subsection Line length and line breaking
@cindex page breaks
@cindex breaking pages
@cindex page layout
@cindex vertical spacing
-The page layout process happens outside the LilyPond formatting
-engine: variables controlling page layout are passed to the output,
-and are further interpreted by @code{lilypond} wrapper program. It
-responds to the following variables in the @code{\paper} block. The
-variable @code{textheight} sets the total height of the music on each
-page. The spacing between systems is controlled with
-@code{interscoreline}, its default is 16pt. The distance between the
-score lines will stretch in order to fill the full page
-@code{interscorelinefill} is set to a positive number. In that case
-@code{interscoreline} specifies the minimum spacing.
-
-@cindex @code{textheight}
-@cindex @code{interscoreline}
-@cindex @code{interscorelinefill}
-
-If the variable @code{lastpagefill} is defined,
-@c fixme: this should only be done if lastpagefill= #t
-systems are evenly distributed vertically on the last page. This
-might produce ugly results in case there are not enough systems on the
-last page. The @command{lilypond-book} command ignores
-@code{lastpagefill}. See @ref{lilypond-book manual} for more
-information.
-
-@cindex @code{lastpagefill}
-
-Page breaks are normally computed by @TeX{}, so they are not under
-direct control of LilyPond. However, you can insert a commands into
-the @file{.tex} output to instruct @TeX{} where to break pages. This
-is done by setting the @code{between-systems-strings} on the
-@internalsref{NonMusicalPaperColumn} where the system is broken.
-An example is shown in @inputfileref{input/regression,between-systems.ly}.
-The predefined command @code{\newpage} also does this.
-
-@cindex paper size
-@cindex page size
-@cindex @code{papersize}
-
-To change the paper size, use the following Scheme code:
-@example
- \paper@{
- #(set-paper-size "a4")
- @}
-@end example
-
-
-@refcommands
-
-@cindex @code{\newpage}
-@code{\newpage}.
-
-
-@seealso
-
-In this manual: @ref{Invoking lilypond}.
-
-Examples: @inputfileref{input/regression,between-systems.ly}.
-
-Internals: @internalsref{NonMusicalPaperColumn}.
-
-@refbugs
-
-LilyPond has no concept of page layout, which makes it difficult to
-reliably choose page breaks in longer pieces.
-
-
-@node Interpretation context
-@section Interpretation context
-
-@menu
-* Creating contexts::
-* Default contexts::
-* Context properties::
-* Defining contexts::
-* Changing contexts locally::
-* Engravers and performers::
-* Defining new contexts::
-@end menu
-
-
-Interpretation contexts are objects that only exist during program
-run. During the interpretation phase (when @code{interpreting music}
-is printed on the standard output), the music expression in a
-@code{\score} block is interpreted in time order, the same order in
-which we hear and play the music. During this phase, the interpretation
-context holds the state for the current point within the music, for
-example:
-@itemize @bullet
-@item What notes are playing at this point?
-
-@item What symbols will be printed at this point?
+The option @code{raggedlast} is similar to @code{raggedright}, but
+only affects the last line of the piece. No restrictions are put on
+that line. The result is similar to formatting paragraphs. In a
+paragraph, the last line simply takes its natural length.
-@item What is the current key signature, time signature, point within
-the measure, etc.?
-@end itemize
-
-Contexts are grouped hierarchically: A @internalsref{Voice} context is
-contained in a @internalsref{Staff} context (because a staff can contain
-multiple voices at any point), a @internalsref{Staff} context is contained in
-@internalsref{Score}, @internalsref{StaffGroup}, or
-@internalsref{ChoirStaff} context.
-Contexts associated with sheet music output are called @emph{notation
-contexts}, those for sound output are called @emph{performance
-contexts}. The default definitions of the standard notation and
-performance contexts can be found in @file{ly/engraver-init.ly} and
-@file{ly/performer-init.ly}, respectively.
+@node Titling
+@subsection Titling
+Titles are created for each @code{\score} block, and over a
+@code{\book}.
-@node Creating contexts
-@subsection Creating contexts
-@cindex @code{\context}
-@cindex context selection
-
-Contexts for a music expression can be selected manually, using one of
-the following music expressions:
+The contents of the titles are taken from the @code{\header} blocks.
+The header block for a book supports the following
+@table @code
+@item title
+ The title of the music. Centered on top of the first page.
+@item subtitle
+ Subtitle, centered below the title.
+@item poet
+ Name of the poet, left flushed below the subtitle.
+@item composer
+ Name of the composer, right flushed below the subtitle.
+@item meter
+ Meter string, left flushed below the poet.
+@item opus
+ Name of the opus, right flushed below the composer.
+@item arranger
+ Name of the arranger, right flushed below the opus.
+@item instrument
+ Name of the instrument, centered below the arranger.
+@item dedication
+ To whom the piece is dedicated.
+@item piece
+ Name of the piece, left flushed below the instrument.
+@end table
-@example
-\new @var{contexttype} @var{musicexpr}
-\context @var{contexttype} [= @var{contextname}] @var{musicexpr}
-@end example
+This is a demonstration of the fields available,
-@noindent
-This means that @var{musicexpr} should be interpreted within a context
-of type @var{contexttype} (with name @var{contextname} if specified).
-If no such context exists, it will be created:
+@lilypond[verbatim]
+\book {
+ \header {
+ title = "Title"
+ subtitle = "(and (the) subtitle)"
+ subsubtitle = "Sub sub title"
+ poet = "Poet"
+ composer = "Composer"
+ texttranslator = "Text Translator"
+ meter = "Meter"
+ arranger = "Arranger"
+ instrument = "Instrument"
+ piece = "Piece"
+ }
-@lilypond[verbatim,raggedright]
-\score {
- \notes \relative c'' {
- c4 <<d4 \context Staff = "another" e4>> f
+ \score {
+ \header {
+ piece = "piece1"
+ opus = "opus1"
+ }
+ { c'1 }
+ }
+ \score {
+ \header {
+ piece = "piece2"
+ opus = "opus2"
+ }
+ { c'1 }
}
}
@end lilypond
-@noindent
-In this example, the @code{c} and @code{d} are printed on the default
-staff. For the @code{e}, a context @code{Staff} called @code{another}
-is specified; since that does not exist, a new context is created.
-Within @code{another}, a (default) Voice context is created for the
-@code{e4}. A context is ended when when all music referring it has
-finished, so after the third quarter, @code{another} is removed.
-
-The @code{\new} construction creates a context with a
-generated, unique @var{contextname}. An expression with
-@code{\new} always leads to a new context. This is convenient
-for creating multiple staves, multiple lyric lines, etc.
-
-When using automatic staff changes, automatic phrasing, etc., the
-context names have special meanings, so @code{\new} cannot be
-used.
-
-
-@node Default contexts
-@subsection Default contexts
-
-Every top level music is interpreted by the @code{Score} context; in
-other words, you may think of @code{\score} working like
-
-@example
-\score @{
- \context Score @var{music}
-@}
-@end example
-
-Music expressions inherit their context from the enclosing music
-expression. Hence, it is not necessary to explicitly specify
-@code{\context} for most expressions. In
-the following example, only the sequential expression has an explicit
-context. The notes contained therein inherit the @code{goUp} context
-from the enclosing music expression.
-
-@lilypond[verbatim,raggedright]
- \notes \context Voice = goUp { c'4 d' e' }
-@end lilypond
-
-
-Second, contexts are created automatically to be able to interpret the
-music expressions. Consider the following example:
-
-@lilypond[verbatim,raggedright]
- \score { \notes { c'4-( d' e'-) } }
-@end lilypond
-
-@noindent
-The sequential music is interpreted by the Score context initially,
-but when a note is encountered, contexts are setup to accept that
-note. In this case, a @code{Voice}, and @code{Staff}
-context are created. The rest of the sequential music is also
-interpreted with the same @code{Voice}, and
-@code{Staff} context, putting the notes on the same staff, in the same
-voice.
-
-@node Context properties
-@subsection Context properties
-
-Contexts have properties. These properties are set from the @file{.ly}
-file using the following expression:
-@cindex context properties
-@cindex properties, context
-
-@example
-\set @var{contextname}.@var{propname} = @var{value}
-@end example
-
-@noindent
-Sets the @var{propname} property of the context @var{contextname} to
-the specified Scheme expression @var{value}. Both @var{propname} and
-@var{contextname} are strings, which can often be written unquoted.
-
-@cindex inheriting
-Properties that are set in one context are inherited by all of the
-contained contexts. This means that a property valid for the
-@internalsref{Voice} context can be set in the @internalsref{Score} context
-(for example) and thus take effect in all @internalsref{Voice} contexts.
-
-Properties can be unset using the following statement.
-@example
-\unset @var{contextname}.@var{propname}
-@end example
-
-@cindex properties, unsetting
-@cindex @code{\unset}
-
-@noindent
-This removes the definition of @var{propname} in @var{contextname}. If
-@var{propname} was not defined in @var{contextname} (but was inherited
-from a higher context), then this has no effect.
-
-If @var{contextname} is left out, then it defaults to the current
-``bottom'' context: this is a context like @internalsref{Voice} that
-cannot contain any other contexts.
-
-
-@node Defining contexts
-@subsection Defining contexts
-
-@cindex context definition
-@cindex translator definition
-
-The most common way to create a new context definition is by extending
-an existing one. An existing context from the paper block is copied
-by referencing a context identifier:
-
-@example
-\paper @{
- \context @{
- @var{context-identifier}
- @}
-@}
-@end example
-
-@noindent
-Every predefined context has a standard identifier. For example, the
-@code{Staff} context can be referred to as @code{\StaffContext}.
-
-The context can then be modified by setting or changing properties,
-e.g.
-@example
-\context @{
- \StaffContext
- Stem \set #'thickness = #2.0
- defaultBarType = #"||"
-@}
-@end example
-These assignments happen before interpretation starts, so a property
-command will override any predefined settings.
-
-@cindex engraver
-
-@refbugs
-
-It is not possible to collect multiple property assignments in a
-variable, and apply to one @code{\context} definition by
-referencing that variable.
-
-@node Changing contexts locally
-@subsection Changing contexts locally
-
+Different fonts may be selected for each element, by using a
+@code{\markup}, e.g.
-Extending an existing context can also be done locally. A piece of
-music can be interpreted in a changed context by using the following syntax
+@verbatim
+ \header {
+ title = \markup { \italic { The italic title } }
+ }
+@end verbatim
-@example
- \with @{
- @var{context modifications}
- @}
-@end example
+A more advanced option is to change the Scheme functions
+@code{make-book-title} and @code{make-score-title} functions, defined
+in the @code{\bookpaper} of the @code{\book} block. These functions
+create a block of titling, given the information in the
+@code{\header}. The init file @file{ly/titling.scm} shows how the
+default format is created, and it may be used as a template for
+different styles.
-These statements comes between @code{\new} or @code{\context} and the
-music to be interpreted. The @var{context modifications} property
-settings and @code{\remove}, @code{\consists} and @code{\consistsend}
-commands. The syntax is similar to the @code{\context} block.
+
-The following example shows how a staff is created with bigger spaces,
-and without a @code{Clef_engraver}.
+@cindex header
+@cindex footer
+@cindex page layout
+@cindex titles
-@lilypond[relative=1,fragment,verbatim]
-<<
- \new Staff { c4 es4 g2 }
- \new Staff \with {
- \override StaffSymbol #'staff-space = #(magstep 1.5)
- fontSize = #1.5
- \remove "Clef_engraver"
- } {
- c4 es4 g2
- } >>
-@end lilypond
-@refbugs
-The command @code{\with} has no effect on contexts that already
-exist.
+@node Page breaking
+@subsection Page breaking
-@node Engravers and performers
-@subsection Engravers and performers
+The default page breaking may be overriden by inserting
+@code{\pageBreak} or @code{\noPageBreak} commands. These commands are
+analogous to @code{\break} and @code{\noBreak}. They should be
+inserted with a bar line. These commands force and forbid a page-break
+from happening.
+Page breaks are computed by the @code{page-breaking} function in the
+@code{\bookpaper} block.
-Each context is composed of a number of building blocks, or plug-ins
-called engravers. An engraver is a specialized C++ class that is
-compiled into the executable. Typically, an engraver is responsible
-for one function: the @code{Slur_engraver} creates only @code{Slur}
-objects, and the @code{Skip_event_swallow_translator} only swallows
-(silently gobbles) @code{SkipEvent}s.
+@refcommands
+@cindex @code{\pageBreak}
+@code{\pageBreak}
+@cindex @code{\noPageBreak}
+@code{\noPageBreak}
+@node Paper size
+@subsection Paper size
-@cindex engraver
-@cindex plug-in
+@cindex paper size
+@cindex page size
+@cindex @code{papersize}
-An existing context definition can be changed by adding or removing an
-engraver. The syntax for these operations is
+To change the paper size, there are two commands,
@example
-\consists @var{engravername}
-\remove @var{engravername}
+ #(set-default-paper-size "a4")
+ \paper@{
+ #(set-paper-size "a4")
+ @}
@end example
+The second one sets the size of the @code{\paper} block that it is in.
-@cindex @code{\consists}
-@cindex @code{\remove}
-
-@noindent
-Here @var{engravername} is a string, the name of an engraver in the
-system. In the following example, the @code{Clef_engraver} is removed
-from the Staff context. The result is a staff without a clef, where
-the middle C is at its default position, the center line:
-
-@lilypond[verbatim,raggedright]
-\score {
- \notes {
- c'4 f'4
- }
- \paper {
- \context {
- \StaffContext
- \remove Clef_engraver
- }
- }
-}
-@end lilypond
-A list of all engravers is in the internal documentation,
-see @internalsref{Engravers}.
-
-@node Defining new contexts
-@subsection Defining new contexts
-
-
-It is also possible to define new contexts from scratch. To do this,
-you must define give the new context a name. In the following
-example, a very simple Staff context is created: one that will put
-note heads on a staff symbol.
+@node Page layout
+@subsection Page layout
-@example
-\context @{
- \type "Engraver_group_engraver"
- \name "SimpleStaff"
- \alias "Staff"
- \consists "Staff_symbol_engraver"
- \consists "Note_head_engraver"
- \consistsend "Axis_group_engraver"
-@}
-@end example
+@cindex page layout
+@cindex margins
+@cindex header, page
+@cindex footer, page
-@noindent
-The argument of @code{\type} is the name for a special engraver that
-handles cooperation between simple engravers such as
-@code{Note_head_engraver} and @code{Staff_symbol_engraver}. This
-should always be @code{Engraver_group_engraver} (unless you are
-defining a Score context from scratch, in which case
-@code{Score_engraver} must be used).
-
-The complete list of context modifiers is the following:
-@itemize @bullet
-@item @code{\alias} @var{alternate-name}:
-This specifies a different name. In the above example,
-@code{\set Staff.X = Y} will also work on @code{SimpleStaff}s.
-
-@item @code{\consistsend} @var{engravername}:
-Analogous to @code{\consists}, but makes sure that
-@var{engravername} is always added to the end of the list of
-engravers.
-
-Engravers that group context objects into axis groups or alignments
-need to be at the end of the list. @code{\consistsend} insures that
-engravers stay at the end even if a user adds or removes engravers.
-
-@item @code{\accepts} @var{contextname}:
-This context can contains @var{contextname} contexts. The first
-@code{\accepts} is created as a default context when events (e.g. notes
-or rests) are encountered.
-
-@item @code{\denies}:
-The opposite of @code{\accepts}.
-
-@item @code{\name} @var{contextname}:
-This sets the type name of the context, e.g. @code{Staff},
-@code{Voice}. If the name is not specified, the translator will not
-do anything.
-@end itemize
+LilyPond will do page layout, setting margins and adding headers and
+footers to each page.
-@c EOF
+The default layout responds to the following settings in the
+@code{\bookpaper} block
+@table @code
+@item hsize
+ The width of the page
+@item vsize
+ The height of the page
+@item top-margin
+ Margin between header and top of the page
+@item bottom-margin
+ Margin between footer and bottom of the page
+@item head-sep
+ Distance between top-most music system and the page header
+@item foot-sep
+ Distance between bottom-most music system and the page footer
+@item raggedbottom
+ If set to true, systems will not be spread across the page.
+@item raggedlastbottom
+ If set to true, systems will not be spread to fill the last page.
+@end table
+The default page header puts the page number and the @code{instrument}
+field from the @code{\header} block on a line.
-@node Output details
-@section Output details
-The default output format is La@TeX{}, which should be run
-through La@TeX{}. Using the option @option{-f}
-(or @option{--format}) other output formats can be selected also, but
-currently none of them work reliably.
-At the beginning of the output file, various global parameters are
-defined. Then the file @file{lilyponddefs.tex} is loaded to define
-the macros used in the code which follows. @file{lilyponddefs.tex}
-includes various other files, partially depending on the global
-parameters.
+@cindex copyright
+@cindex tagline
-Now the music is output system by system (a `system' consists of all
-staves belonging together). From @TeX{}'s point of view, a system is an
-@code{\hbox} which contains a lowered @code{\vbox} so that it is centered
-vertically on the baseline of the text. Between systems,
-@code{\interscoreline} is inserted vertically to have stretchable space.
-The horizontal dimension of the @code{\hbox} is given by the
-@code{linewidth} parameter from LilyPond's @code{\paper} block.
+The default footer is empty, except for the first page, where it the
+@code{copyright} field from @code{\header} is inserted, and the last
+page, where @code{tagline} from @code{\header} is added. The default
+tagline is ``Engraved by LilyPond (@var{version})''.
-After the last system LilyPond emits a stronger variant of
-@code{\interscoreline} only if the macro
-@code{\lilypondpaperlastpagefill} is not defined (flushing the systems
-to the top of the page). You can avoid that by setting the variable
-@code{lastpagefill} in LilyPond's @code{\paper} block.
+The header and footer are created by the functions @code{make-footer}
+and @code{make-header}, defined in @code{\bookpaper}. The default
+implementations are in @file{scm/page-layout.scm}.
-It is possible to fine-tune the vertical offset further by defining the
-macro @code{\lilypondscoreshift}:
+The following settings influence the header and footer layout.
-@example
-\def\lilypondscoreshift@{0.25\baselineskip@}
-@end example
+@table @code
+@item printpagenumber
+ this boolean controls whether a pagenumber is printed.
+@end table
-@noindent
-where @code{\baselineskip} is the distance from one text line to the next.
-Here an example how to embed a small LilyPond file @code{foo.ly} into
-running La@TeX{} text without using the @code{lilypond-book} script
-(@pxref{lilypond-book manual}):
-@example
-\documentclass@{article@}
+The page layout itself is done by two functions:
+@code{page-music-height} and @code{page-make-stencil}. The former
+tells the line-breaking algorithm how much space can be spent on a
+page, the latter creates the actual page given the system to put on it.
-\def\lilypondpaperlastpagefill@{@}
-\lineskip 5pt
-\def\lilypondscoreshift@{0.25\baselineskip@}
-\begin@{document@}
-This is running text which includes an example music file
-\input@{foo.tex@}
-right here.
-\end@{document@}
-@end example
+@seealso
-The file @file{foo.tex} has been simply produced with
+Examples: @inputfileref{input/test/,page-breaks.ly}
-@example
- lilypond-bin foo.ly
-@end example
-The call to @code{\lineskip} assures that there is enough vertical space
-between the LilyPond box and the surrounding text lines.
projects / lilypond.git / blobdiff