@node Tweaking output
@chapter Tweaking output
-Tweak explanation.
+This chapter discusses how to modify output. LilyPond is extremely
+configurable; virtually every fragment of output may be changed.
@menu
+* Moving objects::
* Fixing overlapping notation::
+* Common tweaks::
+* Default files::
+* Advanced tweaks with Scheme::
@end menu
-@node Fixing overlapping notation
-@section Fixing overlapping notation
+@node Moving objects
+@section Moving objects
-This may come as a surprise, but LilyPond isn't perfect. Some notation
+This may come as a surprise, but LilyPond is not perfect. Some notation
elements can overlap. This is unfortunate, but (in most cases) is easily
solved.
taste in notation. Try the above example with 2.3... but also try higher
(and lower) numbers. Which do you think looks the best?
+The @code{staff-padding} property is closely related. @code{padding}
+controls the minimum amount of space between an object and the nearest
+other object (generally the note or the staff lines);
+@code{staff-padding} controls the minimum amount of space between an
+object and the staff. This is a subtle difference, but you can see
+the behavior here.
+
+@lilypond[quote,fragment,ragged-right,verbatim,relative=2]
+c4^"piu mosso" b a b
+\once \override TextScript #'padding = #2.6
+c4^"piu mosso" d e f
+\once \override TextScript #'staff-padding = #2.6
+c4^"piu mosso" fis a g
+\break
+c,,4^"piu mosso" b a b
+\once \override TextScript #'padding = #2.6
+c4^"piu mosso" d e f
+\once \override TextScript #'staff-padding = #2.6
+c4^"piu mosso" fis a g
+@end lilypond
+
@cindex extra-offset
Another solution gives us complete control over placing the object -- we
can move it horizontally or vertically. This is done with the
@code{extra-offset} property. It is slightly more complicated and can
cause other problems. When we move objects with @code{extra-offset},
-the movement is done after LilyPond has placed all other objects. This means
+the movement is done after LilyPond has placed all other objects. This
+means
that the result can overlap with other objects.
@lilypond[quote,fragment,ragged-right,verbatim,relative=2]
looking at the output. You might prefer the text to be slightly higher,
or to the left, or whatever. Try it and look at the result!
+One final warning: in this section, we used
+
+@example
+\once \override TextScript @dots{}
+@end example
+
+This tweaks the display of text for the next note. If the note has
+no text, this tweak does nothing (and does @strong{not} wait until
+the next bit of text). To change the behavior of everything after
+the command, omit the @code{\once}. To stop this tweak, use a
+@code{\revert}. This is explained in depth in
+@ref{The \override command}.
+
+@lilypond[quote,fragment,ragged-right,verbatim,relative=3]
+c4^"piu mosso" b
+\once \override TextScript #'padding = #2.6
+ a4 b
+c4^"piu mosso" d e f
+\once \override TextScript #'padding = #2.6
+c4^"piu mosso" d e f
+c4^"piu mosso" d e f
+\break
+\override TextScript #'padding = #2.6
+c4^"piu mosso" d e f
+c4^"piu mosso" d e f
+\revert TextScript #'padding
+c4^"piu mosso" d e f
+@end lilypond
@seealso
This manual: @ref{The \override command}, @ref{Common tweaks}.
+
+@node Fixing overlapping notation
+@section Fixing overlapping notation
+
+In @ref{Moving objects}, we saw how to move a @code{TextScript}
+object. The same mechanism can be used to move other types of
+objects; simply replace @code{TextScript} with the name of
+another object.
+
+To find the object name, look at the ``@strong{see also}'' at
+bottom of the relevant documentation page. For example, at
+the bottom of @ref{Dynamics}, we see
+
+@quotation
+@seealso
+
+Program reference: @internalsref{DynamicText}, @internalsref{Hairpin}.
+Vertical positioning of these symbols is handled by
+@internalsref{DynamicLineSpanner}.
+@end quotation
+
+@noindent
+So to move dynamics around, we use
+
+@example
+\override DynamicLineSpanner #'padding = #2.0
+@end example
+
+We cannot list every object, but here is a list of the most
+common objects.
+
+@multitable @columnfractions .33 .66
+@headitem Object type @tab Object name
+@item Dynamics @tab @code{DynamicLineSpanner}
+@item Ties @tab @code{Tie}
+@item Slurs @tab @code{Slur}
+@item Articulations @tab @code{Script}
+@item Fingerings @tab @code{Fingering}
+@item Text e.g. @code{^"text"} @tab @code{TextScript}
+@item Rehearsal / Text marks @tab @code{RehearsalMark}
+@end multitable
+
+
+@node Common tweaks
+@section Common tweaks
+
+Some overrides are so common that predefined commands are provided as
+short-cuts, such as @code{\slurUp} and @code{\stemDown}. These
+commands are described in the Notation Reference under the appropriate
+sections.
+
+The complete list of modifications available for each type of
+object (like slurs or beams) are documented in the Program
+Reference. However, many layout objects share properties which can be
+used to apply generic tweaks.
+
+@itemize @bullet
+
+@cindex padding
+
+@item
+The @code{padding} property can be set to increase
+(or decrease) the distance between symbols that are printed
+above or below notes. This applies to all objects with
+@code{side-position-interface}.
+
+@lilypond[quote,fragment,relative=1,verbatim]
+c2\fermata
+\override Script #'padding = #3
+b2\fermata
+@end lilypond
+
+@lilypond[quote,fragment,relative=1,verbatim]
+% This will not work, see below:
+\override MetronomeMark #'padding = #3
+\tempo 4=120
+c1
+% This works:
+\override Score.MetronomeMark #'padding = #3
+\tempo 4=80
+d1
+@end lilypond
+
+Note in the second example how important it is to figure out what
+context handles a certain object. Since the @code{MetronomeMark} object
+is handled in the @code{Score} context, property changes in the
+@code{Voice} context will not be noticed. For more details, see
+@ref{Constructing a tweak}.
+
+@cindex extra-offset
+
+@item
+The @code{extra-offset} property moves objects around
+in the output; it requires a pair of numbers. The first number
+controls horizontal movement; a positive number will
+move the object to the right. The second number controls vertical
+movement; a positive number will move it higher. The
+@code{extra-offset} property is a low-level feature: the
+formatting engine is completely oblivious to these offsets.
+
+In the following example, the second fingering is moved a little to
+the left, and 1.8 staff space downwards:
+
+@lilypond[quote,fragment,relative=1,verbatim]
+\stemUp
+f-5
+\once \override Fingering
+ #'extra-offset = #'(-0.3 . -1.8)
+f-5
+@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, ties, and beams can be attached to it.
+
+@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[quote,fragment,relative=2]
+<< {
+ b8~ b8\noBeam
+} \\ {
+ b[ g8]
+} >>
+@end lilypond
+
+@noindent
+and blanking the first up-stem in that voice, the tie appears to cross
+voices:
+
+@lilypond[quote,fragment,relative=2,verbatim]
+<< {
+ \once \override Stem #'transparent = ##t
+ b8~ b8\noBeam
+} \\ {
+ b[ g8]
+} >>
+@end lilypond
+
+@end itemize
+
+@cindex Tweaks, distances
+@cindex Distances
+
+Distances in LilyPond are measured in staff-spaces, while most
+thickness properties are measured in line-thickness. Some
+properties are different; for example, the thickness of beams
+are measured in staff-spaces. For more information, see the
+relevant portion of the program reference.
+
+
+@node Default files
+@section Default files
+
+The Program Reference documentation contains a lot of information
+about LilyPond, but even more information can be gathered from
+looking at the internal LilyPond files.
+
+Some default settings (such as the definitions for
+@code{\header@{@}}s) are stored as @code{.ly} files. Other
+settings (such as the definitions of markup commands) are
+stored as @code{.scm} (Scheme) files. Further explanation is
+outside the scope of this manual; users should be warned that
+a substantial amount of technical knowledge or time is required
+to understand these files.
+
+@itemize bullet
+
+@item Linux: @file{@{INSTALLDIR@}/lilypond/usr/share/lilypond/current/}
+
+@item OSX:
+@file{@{INSTALLDIR@}/LilyPond.app/Contents/Resources/share/lilypond/current/}.
+To access this, either @code{cd} into this directory from
+the Terminal, or control-click on the LilyPond application
+and select "Show Package Contents".
+
+@item Windows: @file{@{INSTALLDIR@}/LilyPond/usr/share/lilypond/current/}
+
+@end itemize
+
+The @file{ly/} and @file{scm/} directories will be of
+particular interest. Files such as @file{ly/property-init.ly} and
+@file{ly/declarations-init.ly} define all the common tweaks.
+
+
+@node Advanced tweaks with Scheme
+@section Advanced tweaks with Scheme
+
+We have seen how LilyPond output can be heavily modified using
+commands like
+@code{\override TextScript #'extra-offset = ( 1 . -1)}. But
+we have even more power if we use Scheme. For a full explantion
+of this, see the @ref{Scheme tutorial} and
+@ref{Interfaces for programmers}.
+
+We can use Scheme to simply @code{\override} commands,
+
+@lilypond[quote,verbatim,ragged-right]
+padText = #(define-music-function (parser location padding) (number?)
+#{
+ \once \override TextScript #'padding = #$padding
+#})
+
+\relative c''' {
+ c4^"piu mosso" b a b
+ \padText #1.8
+ c4^"piu mosso" d e f
+ \padText #2.6
+ c4^"piu mosso" fis a g
+}
+@end lilypond
+
+We can use it to create new commands,
+
+@lilypond[quote,verbatim,ragged-right]
+tempoMark = #(define-music-function (parser location padding marktext)
+ (number? string?)
+#{
+ \once \override Score . RehearsalMark #'padding = $padding
+ \once \override Score . RehearsalMark #'no-spacing-rods = ##t
+ \mark \markup { \bold $marktext }
+#})
+
+\relative c'' {
+c2 e
+\tempoMark #3.0 #"Allegro"
+g c
+}
+@end lilypond
+
+Even music expressions can be passed in.
+
+@lilypond[quote,verbatim,ragged-right]
+pattern = #(define-music-function (parser location x y) (ly:music? ly:music?)
+#{
+ $x e8 a b $y b a e
+#})
+
+\relative c''{
+ \pattern c8 c8\f
+ \pattern {d16 dis} { ais16-> b\p }
+}
+@end lilypond
+
projects / lilypond.git / blobdiff