1 @c -*- coding: utf-8; mode: texinfo; -*-
2 @c This file is part of lilypond.tely
4 Translation of GIT committish: FILL-IN-HEAD-COMMITTISH
6 When revising a translation, copy the HEAD committish of the
7 version that you are working on. See TRANSLATION for details.
12 @node Changing defaults
13 @chapter Changing defaults
15 @strong{N.B. This Chapter is still being developed at present.}
17 The purpose of LilyPond's design is to provide the finest quality
18 output by default. Nevertheless, it may happen that you need to
19 change this default layout. The layout is controlled through a large
20 number of @q{knobs and switches} collectively called @q{properties}.
21 A tutorial introduction to accessing and modifying these properties
22 can be found in the Learning Manual, see @rlearning{Tweaking output}.
23 This should be read first. This chapter covers similar ground, but
24 in a style more appropriate to a reference manual.
26 @cindex Internals Reference
28 The definitive description of the controls available for tuning can
29 be found in a separate document: @rinternalsnamed{Top,the Internals
30 Reference}. That manual lists all the variables, functions and
31 options available in LilyPond. It is written as a HTML document,
33 @c leave the @uref as one long line.
34 @uref{http://@/lilypond@/.org/@/doc/@/stable/@/Documentation/@/user/@/lilypond@/-internals/,on@/-line},
35 and is also included with the LilyPond documentation package.
37 @c TODO The following is at variance to what actually follows. Fix -td
40 There are four areas where the default settings may be changed:
44 Automatic notation: changing the automatic creation of notation
45 elements. For example, changing the beaming rules.
48 Output: changing the appearance of individual
49 objects. For example, changing stem directions or the location of
53 Context: changing aspects of the translation from music events to
54 notation. For example, giving each staff a separate time signature.
57 Page layout: changing the appearance of the spacing, line
58 breaks, and page dimensions. These modifications are discussed
59 @c in @ref{notation}, and @ref{Spacing issues}.
62 Internally, LilyPond uses Scheme (a LISP dialect) to provide
63 infrastructure. Overriding layout decisions in effect accesses the
64 program internals, which requires Scheme input. Scheme elements are
65 introduced in a @code{.ly} file with the hash mark
66 @code{#}.@footnote{@rlearning{Scheme tutorial}, contains a short tutorial
67 on entering numbers, lists, strings, and symbols in Scheme.}
73 * Interpretation contexts::
74 * Explaining the Internals Reference::
75 * Modifying properties::
76 * Useful concepts and properties::
78 * Discussion of specific tweaks::
82 @node Interpretation contexts
83 @section Interpretation contexts
85 This section describes what contexts are, and how to modify them.
88 * Contexts explained::
90 * Modifying context plug-ins::
91 * Changing context default settings::
92 * Defining new contexts::
97 @node Contexts explained
98 @subsection Contexts explained
101 @c TODO Rethink and rewrite
103 >> > > - list of contexts: my *danger unmaintainable*
104 >> > > alarm just went off. I'm
106 I knew it would... And leaving out some of them is perfectly fine
108 I do think that a list like this, with the main contexts and a
110 description of what they do (perhaps also with a note about what
112 behavior is associated with each of them, but this may be
114 should be there, and then we could simply list the remaining ones
116 further explanation and with links to the IR.
119 @c TODO Improve layout, order and consistency of wording -td
121 @c TODO Add introduction which explains contexts in generality -td
123 @c TODO Describe propagation of property values -td
125 Contexts are arranged heirarchically:
128 * Score - the master of all contexts::
129 * Top-level contexts - staff containers::
130 * Intermediate-level contexts - staves::
131 * Bottom-level contexts - voices::
134 @node Score - the master of all contexts
135 @unnumberedsubsubsec Score - the master of all contexts
137 This is the top level notation context. No other context can
138 contain a Score context. By default the Score context handles
139 the administration of time signatures and makes sure that items
140 such as clefs, time signatures, and key-signatures are aligned
143 A Score context is instantiated implicitly when a
144 @code{\score @{@dots{}@}} or @code{\layout @{@dots{}@}} block is
145 processed, or explicitly when a @code{\new Score} command is
148 @node Top-level contexts - staff containers
149 @unnumberedsubsubsec Top-level contexts - staff containers
151 @strong{@emph{StaffGroup}}
153 Groups staves while adding a bracket on the left side, grouping
154 the staves together. The bar lines of the contained staves are
155 connected vertically. StaffGroup only consists of a collection
156 of staves, with a bracket in front and spanning bar lines.
158 @strong{@emph{ChoirStaff}}
160 Identical to StaffGroup except that the bar lines of the contained
161 staves are not connected vertically.
163 @strong{@emph{GrandStaff}}
165 A group of staves, with a brace on the left side, grouping
166 the staves together. The bar lines of the contained staves are
167 connected vertically.
169 @strong{@emph{PianoStaff}}
171 TODO No longer correct? Check. -td
173 Just like GrandStaff but with a forced distance between the
174 staves, so cross staff beaming and slurring can be used.
176 @strong{@emph{InnerStaffGroup}}
180 @strong{@emph{InnerChoirStaff}}
184 @node Intermediate-level contexts - staves
185 @unnumberedsubsubsec Intermediate-level contexts - staves
187 @strong{@emph{Staff}}
189 Handles clefs, bar lines, keys, accidentals. It can contain
192 @strong{@emph{RhythmicStaff}}
194 Like Staff but for printing rhythms. Pitches are ignored;
195 the notes are printed on one line.
197 @strong{@emph{TabStaff}}
199 Context for generating tablature. By default lays the music
200 expression out as a guitar tablature, printed on six lines.
202 @strong{@emph{DrumStaff}}
204 Handles typesetting for percussion. Can contain DrumVoice
206 @strong{@emph{VaticanaStaff}}
208 Same as Staff, except that it is designed for typesetting
209 a piece in gregorian style.
211 @strong{@emph{MensuralStaff}}
213 Same as Staff, except that it is designed for typesetting
214 a piece in mensural style.
216 @node Bottom-level contexts - voices
217 @unnumberedsubsubsec Bottom-level contexts - voices
219 Voice-level contexts initialise certain properties and start
220 appropriate engravers. Being bottom-level contexts, they cannot
221 contain other contexts.
223 @strong{@emph{Voice}}
225 Corresponds to a voice on a staff. This context handles the
226 conversion of dynamic signs, stems, beams, super- and sub-scripts,
227 slurs, ties, and rests. You have to instantiate this explicitly
228 if you require multiple voices on the same staff.
230 @strong{@emph{VaticanaVoice}}
232 Same as Voice, except that it is designed for typesetting a piece
235 @strong{@emph{MensuralVoice}}
237 Same as Voice, with modifications for typesetting a piece in
240 @strong{@emph{Lyrics}}
242 Corresponds to a voice with lyrics. Handles the printing of a
243 single line of lyrics.
245 @strong{@emph{DrumVoice}}
247 The voice context used in a percussion staff.
249 @strong{@emph{FiguredBass}}
251 The context in which BassFigure objects are created from
252 input entered in @code{\figuremode} mode.
254 @strong{@emph{TabVoice}}
256 The voice context used within a TabStaff context. Usually left to
257 be created implicitly.
259 @strong{@emph{ChordNames}}
261 Typesets chord names.
263 ------------------------------
267 Then the following, which I don't know what to do with:
269 * GregorianTranscriptionVoice
270 * GregorianTranscriptionStaff
273 Engraves fretboards from chords. Not easy... Not
275 There is now some documentation on FretBoards in the NR, under
276 instrument-specific notation -- cds.
280 * CueVoice Not documented
282 Hard coded entry point for LilyPond. Cannot be tuned.
284 Silently discards all musical information given to this
288 @node Creating contexts
289 @subsection Creating contexts
291 @c TODO \new Score and \score
292 @c TODO more complete descriptions rather than learning style
294 For scores with only one voice and one staff, contexts are
295 created automatically. For more complex scores, it is necessary to
296 create them by hand. There are three commands that do this.
301 The easiest command is @code{\new}, and it also the quickest to type.
302 It is prepended to a music expression, for example
306 @cindex Context, creating
309 \new @var{type} @var{music expression}
313 where @var{type} is a context name (like @code{Staff} or
314 @code{Voice}). This command creates a new context, and starts
315 interpreting the @var{music expression} with that.
317 A practical application of @code{\new} is a score with many
318 staves. Each part that should be on its own staff, is preceded with
321 @lilypond[quote,verbatim,relative=2,ragged-right,fragment]
328 The @code{\new} command may also give a name to the context,
331 \new @var{type} = @var{id} @var{music}
333 However, this user specified name is only used if there is no other
334 context already earlier with the same name.
340 Like @code{\new}, the @code{\context} command also directs a music
341 expression to a context object, but gives the context an explicit name. The
345 \context @var{type} = @var{id} @var{music}
348 This form will search for an existing context of type @var{type}
349 called @var{id}. If that context does not exist yet, a new
350 context with the specified name is created. This is useful if
351 the context is referred to later on. For example, when
352 setting lyrics the melody is in a named context
355 \context Voice = "@b{tenor}" @var{music}
359 so the texts can be properly aligned to its notes,
362 \new Lyrics \lyricsto "@b{tenor}" @var{lyrics}
367 Another possible use of named contexts is funneling two different
368 music expressions into one context. In the following example,
369 articulations and notes are entered separately,
373 arts = @{ s4-. s4-> @}
376 They are combined by sending both to the same @code{Voice} context,
380 \new Staff \context Voice = "A" \music
381 \context Voice = "A" \arts
384 @lilypond[quote,ragged-right]
388 \new Staff \context Voice = "A" \music
389 \context Voice = "A" \arts
393 With this mechanism, it is possible to define an Urtext (original
394 edition), with the option to put several distinct articulations on the
397 @cindex creating contexts
400 The third command for creating contexts is
402 \context @var{type} @var{music}
407 This is similar to @code{\context} with @code{= @var{id}}, but matches
408 any context of type @var{type}, regardless of its given name.
410 This variant is used with music expressions that can be interpreted at
411 several levels. For example, the @code{\applyOutput} command (see
412 @ref{Running a function on all layout objects}). Without an explicit
413 @code{\context}, it is usually applied to @code{Voice}
416 \applyOutput #'@var{context} #@var{function} % apply to Voice
419 To have it interpreted at the @code{Score} or @code{Staff} level use
423 \applyOutput #'Score #@var{function}
424 \applyOutput #'Staff #@var{function}
430 @node Modifying context plug-ins
431 @subsection Modifying context plug-ins
433 @c TODO Should this be Modifying engravers or Modifying contexts?
435 Notation contexts (like @code{Score} and @code{Staff}) not only
437 they also contain plug-ins called @q{engravers} that create notation
438 elements. For example, the @code{Voice} context contains a
439 @code{Note_head_engraver} and the @code{Staff} context contains a
440 @code{Key_signature_engraver}.
442 For a full a description of each plug-in, see
444 @rinternals{Engravers and Performers}.
447 Internals Reference @expansion{} Translation @expansion{} Engravers.
449 Every context described in
451 @rinternals{Contexts}
454 Internals Reference @expansion{} Translation @expansion{} Context.
456 lists the engravers used for that context.
459 It can be useful to shuffle around these plug-ins. This is done by
460 starting a new context with @code{\new} or @code{\context}, and
466 \new @var{context} \with @{
479 where the @dots{} should be the name of an engraver. Here is a simple
480 example which removes @code{Time_signature_engraver} and
481 @code{Clef_engraver} from a @code{Staff} context,
483 @lilypond[quote,relative=1,verbatim,fragment]
489 \remove "Time_signature_engraver"
490 \remove "Clef_engraver"
497 In the second staff there are no time signature or clef symbols. This
498 is a rather crude method of making objects disappear since it will affect
499 the entire staff. This method also influences the spacing, which may or
500 may not be desirable. More sophisticated methods of blanking objects
501 are shown in @rlearning{Visibility and color of objects}.
503 The next example shows a practical application. Bar lines and time
504 signatures are normally synchronized across the score. This is done
505 by the @code{Timing_translator} and @code{Default_bar_line_engraver}.
506 This plug-in keeps an administration of time signature, location
507 within the measure, etc. By moving these engraver from @code{Score} to
508 @code{Staff} context, we can have a score where each staff has its own
511 @cindex polymetric scores
512 @cindex Time signatures, multiple
514 @lilypond[quote,relative=1,ragged-right,verbatim,fragment]
516 \remove "Timing_translator"
517 \remove "Default_bar_line_engraver"
520 \consists "Timing_translator"
521 \consists "Default_bar_line_engraver"
527 \consists "Timing_translator"
528 \consists "Default_bar_line_engraver"
538 Usually the order in which the engravers are specified
539 does not matter, but in a few special cases the order
540 is important, for example where one engraver writes
541 a property and another reads it, or where one engraver
542 creates a grob and another must process it. The order in
543 which the engravers are specified is the order in which
544 they are called to carry out their processing.
546 The following orderings are important: the
547 @code{Bar_engraver} must normally be first, and
548 the @code{New_fingering_engraver} must come before
549 the @code{Script_column_engraver}. There may be others
550 with ordering dependencies.
552 @node Changing context default settings
553 @subsection Changing context default settings
555 The adjustments of the previous subsections (
556 @ref{The set command}, @ref{Modifying context plug-ins}, and
557 @ref{Overview of modifying properties}) can also be entered
558 separately from the music in the @code{\layout} block,
567 \override Stem #'thickness = #4.0
568 \remove "Time_signature_engraver"
573 The @code{\Staff} command brings in the existing definition of the
574 staff context so that it can be modified.
579 \override Stem #'thickness = #4.0
580 \remove "Time_signature_engraver"
584 affect all staves in the score. Other contexts can be modified
587 The @code{\set} keyword is optional within the @code{\layout} block, so
603 It is not possible to collect context changes in a variable and apply
604 them to a @code{\context} definition by referring to that variable.
606 The @code{\RemoveEmptyStaffContext} will overwrite your current
607 @code{\Staff} settings. If you wish to change the defaults for a
608 staff which uses @code{\RemoveEmptyStaffContext}, you must do so
609 after calling @code{\RemoveEmptyStaffContext}, ie
614 \RemoveEmptyStaffContext
616 \override Stem #'thickness = #4.0
621 TODO: add \with in here.
625 @node Defining new contexts
626 @subsection Defining new contexts
628 Specific contexts, like @code{Staff} and @code{Voice}, are made of
629 simple building blocks. It is possible to create new types of
630 contexts with different combinations of engraver plug-ins.
632 The next example shows how to build a different type of
633 @code{Voice} context from scratch. It will be similar to
634 @code{Voice}, but only prints centered slash note heads. It can be used
635 to indicate improvisation in jazz pieces,
637 @lilypond[quote,ragged-right]
640 \type "Engraver_group"
641 \consists "Note_heads_engraver"
642 \consists "Text_engraver"
643 \consists Pitch_squash_engraver
644 squashedPosition = #0
645 \override NoteHead #'style = #'slash
646 \override Stem #'transparent = ##t
650 \accepts "ImproVoice"
654 a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
655 c4 c^"undress" c_"while playing :)" c }
661 These settings are defined within a @code{\context} block inside a
662 @code{\layout} block,
672 In the following discussion, the example input shown should go in place
673 of the @dots{} in the previous fragment.
675 First it is necessary to define a name for the new context:
681 Since it is similar to the @code{Voice}, we want commands that work
682 on (existing) @code{Voice}s to remain working. This is achieved by
683 giving the new context an alias @code{Voice},
689 The context will print notes and instructive texts, so we need to add
690 the engravers which provide this functionality,
693 \consists Note_heads_engraver
694 \consists Text_engraver
697 but we only need this on the center line,
700 \consists Pitch_squash_engraver
701 squashedPosition = #0
704 The @rinternals{Pitch_squash_engraver} modifies note heads (created
705 by @rinternals{Note_heads_engraver}) and sets their vertical
706 position to the value of @code{squashedPosition}, in this case@tie{}@code{0},
709 The notes look like a slash, and have no stem,
712 \override NoteHead #'style = #'slash
713 \override Stem #'transparent = ##t
716 All these plug-ins have to cooperate, and this is achieved with a
717 special plug-in, which must be marked with the keyword @code{\type}.
718 This should always be @code{Engraver_group}.
721 \type "Engraver_group"
729 \type "Engraver_group"
730 \consists "Note_heads_engraver"
731 \consists "Text_engraver"
732 \consists Pitch_squash_engraver
733 squashedPosition = #0
734 \override NoteHead #'style = #'slash
735 \override Stem #'transparent = ##t
741 Contexts form hierarchies. We want to hang the @code{ImproVoice}
742 under @code{Staff}, just like normal @code{Voice}s. Therefore, we
743 modify the @code{Staff} definition with the @code{\accepts}
754 The opposite of @code{\accepts} is @code{\denies},
755 which is sometimes needed when reusing existing context definitions.
757 Putting both into a @code{\layout} block, like
767 \accepts "ImproVoice"
772 Then the output at the start of this subsection can be entered as
780 c c_"while playing :)"
787 @node Aligning contexts
788 @subsection Aligning contexts
790 New contexts may be aligned above or below existing contexts. This
791 could be useful in setting up a vocal staff (@rlearning{Vocal ensembles}) and
794 @c TODO Better example needed. Ref LM, and expand on it.
797 @findex alignAboveContext
798 @findex alignBelowContext
800 @lilypond[quote,ragged-right]
803 \relative c' \new Staff = "main" {
806 \new Staff \with {alignAboveContext=main} \ossia
814 @node Explaining the Internals Reference
815 @section Explaining the Internals Reference
819 * Navigating the program reference::
820 * Layout interfaces::
821 * Determining the grob property::
822 * Naming conventions::
825 @node Navigating the program reference
826 @subsection Navigating the program reference
828 @c TODO remove this (it's in the LM)
829 @c Replace with more factual directions
831 Suppose we want to move the fingering indication in the fragment
834 @lilypond[quote,fragment,relative=2,verbatim]
840 If you visit the documentation on fingering instructions (in
841 @ref{Fingering instructions}), you will notice:
846 Internals Reference: @rinternals{Fingering}.
851 @c outdated info; probably will delete.
853 This fragment points to two parts of the program reference: a page
854 on @code{FingeringEvent} and one on @code{Fingering}.
856 The page on @code{FingeringEvent} describes the properties of the music
857 expression for the input @code{-2}. The page contains many links
858 forward. For example, it says
861 Accepted by: @rinternals{Fingering_engraver},
865 That link brings us to the documentation for the Engraver, the
869 This engraver creates the following layout objects: @rinternals{Fingering}.
872 In other words, once the @code{FingeringEvent}s are interpreted, the
873 @code{Fingering_engraver} plug-in will process them.
877 @c I can't figure out what this is supposed to mean. -gp
879 The @code{Fingering_engraver} is also listed to create
880 @rinternals{Fingering} objects,
882 @c old info? it doesn't make any sense to me with our current docs.
884 second bit of information listed under @b{See also} in the Notation
889 The programmer's reference is available as an HTML document. It is
890 highly recommended that you read it in HTML form, either online or
891 by downloading the HTML documentation. This section will be much more
892 difficult to understand if you are using the
896 Follow the link to @rinternals{Fingering}. At the top of the
900 Fingering objects are created by: @rinternals{Fingering_engraver} and
901 @rinternals{New_fingering_engraver}.
904 By following related links inside the program reference, we can follow the
905 flow of information within the program:
909 @item @rinternals{Fingering}:
910 @rinternals{Fingering} objects are created by:
911 @rinternals{Fingering_engraver}
913 @item @rinternals{Fingering_engraver}:
914 Music types accepted: @rinternals{fingering-event}
916 @item @rinternals{fingering-event}:
917 Music event type @code{fingering-event} is in Music expressions named
918 @rinternals{FingeringEvent}
921 This path goes against the flow of information in the program: it
922 starts from the output, and ends at the input event. You could
923 also start at an input event, and read with the flow of
924 information, eventually ending up at the output object(s).
926 The program reference can also be browsed like a normal document. It
929 @rinternals{Music definitions},
932 @code{Music definitions}
934 on @rinternals{Translation}, and the @rinternals{Backend}. Every
935 chapter lists all the definitions used and all properties that may be
939 @node Layout interfaces
940 @subsection Layout interfaces
942 @cindex interface, layout
943 @cindex layout interface
946 The HTML page that we found in the previous section describes the
947 layout object called @rinternals{Fingering}. Such an object is a
948 symbol within the score. It has properties that store numbers (like
949 thicknesses and directions), but also pointers to related objects. A
950 layout object is also called a @emph{Grob}, which is short for Graphical
951 Object. For more details about Grobs, see @rinternals{grob-interface}.
953 The page for @code{Fingering} lists the definitions for the
954 @code{Fingering} object. For example, the page says
957 @code{padding} (dimension, in staff space):
963 which means that the number will be kept at a distance of at least 0.5
967 Each layout object may have several functions as a notational or
968 typographical element. For example, the Fingering object
969 has the following aspects
973 Its size is independent of the horizontal spacing, unlike slurs or beams.
976 It is a piece of text. Granted, it is usually a very short text.
979 That piece of text is typeset with a font, unlike slurs or beams.
982 Horizontally, the center of the symbol should be aligned to the
983 center of the note head.
986 Vertically, the symbol is placed next to the note and the staff.
989 The vertical position is also coordinated with other superscript
990 and subscript symbols.
993 Each of these aspects is captured in so-called @emph{interface}s,
994 which are listed on the @rinternals{Fingering} page at the bottom
997 This object supports the following interfaces:
998 @rinternals{item-interface},
999 @rinternals{self-alignment-interface},
1000 @rinternals{side-position-interface}, @rinternals{text-interface},
1001 @rinternals{text-script-interface}, @rinternals{font-interface},
1002 @rinternals{finger-interface}, and @rinternals{grob-interface}.
1005 Clicking any of the links will take you to the page of the respective
1006 object interface. Each interface has a number of properties. Some of
1007 them are not user-serviceable (@q{Internal properties}), but others
1010 We have been talking of @emph{the} @code{Fingering} object, but actually it
1011 does not amount to much. The initialization file (see
1012 @rlearning{Other sources of information})
1013 @file{scm/@/define@/-grobs@/.scm} shows the soul of the @q{object},
1018 (avoid-slur . around)
1019 (slur-padding . 0.2)
1020 (staff-padding . 0.5)
1021 (self-alignment-X . 0)
1022 (self-alignment-Y . 0)
1023 (script-priority . 100)
1024 (stencil . ,ly:text-interface::print)
1025 (direction . ,ly:script-interface::calc-direction)
1026 (font-encoding . fetaNumber)
1027 (font-size . -5) ; don't overlap when next to heads.
1028 (meta . ((class . Item)
1029 (interfaces . (finger-interface
1031 text-script-interface
1033 side-position-interface
1034 self-alignment-interface
1035 item-interface))))))
1039 As you can see, the @code{Fingering} object is nothing more than a
1040 bunch of variable settings, and the webpage in the Internals Reference
1041 is directly generated from this definition.
1044 @node Determining the grob property
1045 @subsection Determining the grob property
1047 @c TODO remove this (it's in the LM)
1048 @c Replace with more factual directions
1050 Recall that we wanted to change the position of the @b{2} in
1052 @lilypond[quote,fragment,relative=2,verbatim]
1058 Since the @b{2} is vertically positioned next to its note, we have to
1059 meddle with the interface associated with this positioning. This is
1060 done using @code{side-position-interface}. The page for this interface
1064 @code{side-position-interface}
1066 Position a victim object (this one) next to other objects (the
1067 support). The property @code{direction} signifies where to put the
1068 victim object relative to the support (left or right, up or down?)
1073 Below this description, the variable @code{padding} is described as
1078 (dimension, in staff space)
1080 Add this much extra space between objects that are next to each other.
1084 By increasing the value of @code{padding}, we can move the
1085 fingering away from the note head. The following command inserts
1086 3 staff spaces of white
1087 between the note and the fingering:
1089 \once \override Voice.Fingering #'padding = #3
1092 Inserting this command before the Fingering object is created,
1093 i.e., before @code{c2}, yields the following result:
1095 @lilypond[quote,relative=2,fragment,verbatim]
1096 \once \override Voice.Fingering #'padding = #3
1103 In this case, the context for this tweak is @code{Voice}. This
1104 fact can also be deduced from the program reference, for the page for
1105 the @rinternals{Fingering_engraver} plug-in says
1108 Fingering_engraver is part of contexts: @dots{} @rinternals{Voice}
1112 @node Naming conventions
1113 @subsection Naming conventions
1115 Another thing that is needed, is an overview of the various naming
1118 scheme functions: lowercase-with-hyphens (incl. one-word
1120 scheme functions: ly:plus-scheme-style
1121 music events, music classes and music properties:
1123 Grob interfaces: scheme-style
1124 backend properties: scheme-style (but X and Y!)
1125 contexts (and MusicExpressions and grobs): Capitalized or
1127 context properties: lowercaseFollowedByCamelCase
1129 Capitalized_followed_by_lowercase_and_with_underscores
1131 Which of these are conventions and which are rules?
1132 Which are rules of the underlying language, and which are
1136 @node Modifying properties
1137 @section Modifying properties
1139 @c TODO change the menu and subsection node names to use
1140 @c backslash once the new macro to handle the refs
1141 @c is available. Need to find and change all refs at
1142 @c the same time. -td
1145 * Overview of modifying properties::
1147 * The override command::
1148 * The tweak command::
1149 * set versus override::
1153 @node Overview of modifying properties
1154 @subsection Overview of modifying properties
1156 Each context is responsible for creating certain types of graphical
1157 objects. The settings used for printing these objects are also stored by
1158 context. By changing these settings, the appearance of objects can be
1161 The syntax for this is
1164 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1167 Here @var{name} is the name of a graphical object, like
1168 @code{Stem} or @code{NoteHead}, and @var{property} is an internal
1169 variable of the formatting system (@q{grob property} or @q{layout
1170 property}). The latter is a symbol, so it must be quoted. The
1171 subsection @ref{Modifying properties}, explains what to fill in
1172 for @var{name}, @var{property}, and @var{value}. Here we only
1173 discuss the functionality of this command.
1178 \override Staff.Stem #'thickness = #4.0
1182 makes stems thicker (the default is 1.3, with staff line thickness as a
1183 unit). Since the command specifies @code{Staff} as context, it only
1184 applies to the current staff. Other staves will keep their normal
1185 appearance. Here we see the command in action:
1187 @lilypond[quote,verbatim,relative=2,fragment]
1189 \override Staff.Stem #'thickness = #4.0
1195 The @code{\override} command changes the definition of the @code{Stem}
1196 within the current @code{Staff}. After the command is interpreted
1197 all stems are thickened.
1199 Analogous to @code{\set}, the @var{context} argument may be left out,
1200 causing the default context @code{Voice} to be used. Adding
1201 @code{\once} applies the change during one timestep only.
1203 @lilypond[quote,fragment,verbatim,relative=2]
1205 \once \override Stem #'thickness = #4.0
1210 The @code{\override} must be done before the object is
1211 started. Therefore, when altering @emph{Spanner} objects such as slurs
1212 or beams, the @code{\override} command must be executed at the moment
1213 when the object is created. In this example,
1215 @lilypond[quote,fragment,verbatim,relative=2]
1216 \override Slur #'thickness = #3.0
1218 \override Beam #'thickness = #0.6
1223 the slur is fatter but the beam is not. This is because the command for
1224 @code{Beam} comes after the Beam is started, so it has no effect.
1226 Analogous to @code{\unset}, the @code{\revert} command for a context
1227 undoes an @code{\override} command; like with @code{\unset}, it only
1228 affects settings that were made in the same context. In other words, the
1229 @code{\revert} in the next example does not do anything.
1232 \override Voice.Stem #'thickness = #4.0
1233 \revert Staff.Stem #'thickness
1236 Some tweakable options are called @q{subproperties} and reside inside
1237 properties. To tweak those, use commands of the form
1239 @c leave this as a long long
1241 \override @var{context}.@var{name} #'@var{property} #'@var{subproperty} = #@var{value}
1248 \override Stem #'details #'beamed-lengths = #'(4 4 3)
1254 Internals: @rinternals{OverrideProperty}, @rinternals{RevertProperty},
1255 @rinternals{PropertySet}, @rinternals{Backend}, and
1256 @rinternals{All layout objects}.
1261 The back-end is not very strict in type-checking object properties.
1262 Cyclic references in Scheme values for properties can cause hangs
1263 or crashes, or both.
1267 @node The set command
1268 @subsection The @code{\set} command
1272 @cindex changing properties
1274 Each context can have different @emph{properties}, variables contained
1275 in that context. They can be changed during the interpretation step.
1276 This is achieved by inserting the @code{\set} command in the music,
1279 \set @var{context}.@var{prop} = #@var{value}
1283 @lilypond[quote,verbatim,relative=2,fragment]
1285 \set Score.skipBars = ##t
1289 This command skips measures that have no notes. The result is that
1290 multi-rests are condensed. The value assigned is a Scheme object. In
1291 this case, it is @code{#t}, the boolean True value.
1293 If the @var{context} argument is left out, then the current bottom-most
1294 context (typically @code{ChordNames}, @code{Voice}, or
1295 @code{Lyrics}) is used. In this example,
1297 @lilypond[quote,verbatim,relative=2,fragment]
1299 \set autoBeaming = ##f
1304 the @var{context} argument to @code{\set} is left out, so automatic
1305 beaming is switched off in the current @rinternals{Voice}. Note that
1306 the bottom-most context does not always contain the property that you
1307 wish to change -- for example, attempting to set the @code{skipBars}
1308 property (of the bottom-most context, in this case @code{Voice}) will
1311 @lilypond[quote,verbatim,relative=2,fragment]
1317 Contexts are hierarchical, so if a bigger context was specified, for
1318 example @code{Staff}, then the change would also apply to all
1319 @code{Voice}s in the current stave. The change is applied
1320 @q{on-the-fly}, during the music, so that the setting only affects the
1321 second group of eighth notes.
1325 There is also an @code{\unset} command,
1327 \unset @var{context}.@var{prop}
1331 which removes the definition of @var{prop}. This command removes
1332 the definition only if it is set in @var{context}, so
1335 \set Staff.autoBeaming = ##f
1339 introduces a property setting at @code{Staff} level. The setting also
1340 applies to the current @code{Voice}. However,
1343 \unset Voice.autoBeaming
1347 does not have any effect. To cancel this setting, the @code{\unset}
1348 must be specified on the same level as the original @code{\set}. In
1349 other words, undoing the effect of @code{Staff.autoBeaming = ##f}
1352 \unset Staff.autoBeaming
1355 Like @code{\set}, the @var{context} argument does not have to be
1356 specified for a bottom context, so the two statements
1359 \set Voice.autoBeaming = ##t
1360 \set autoBeaming = ##t
1368 Settings that should only apply to a single time-step can be entered
1369 with @code{\once}, for example in
1371 @lilypond[quote,verbatim,relative=2,fragment]
1373 \once \set fontSize = #4.7
1378 the property @code{fontSize} is unset automatically after the second
1381 A full description of all available context properties is in the
1382 program reference, see
1384 @rinternals{Tunable context properties}.
1387 Translation @expansion{} Tunable context properties.
1392 @node The override command
1393 @subsection The @code{\override} command
1395 Commands which change output generally look like
1398 \override Voice.Stem #'thickness = #3.0
1402 To construct this tweak we must determine these bits of information:
1405 @item the context: here @code{Voice}.
1406 @item the layout object: here @code{Stem}.
1407 @item the layout property: here @code{thickness}.
1408 @item a sensible value: here @code{3.0}.
1411 Some tweakable options are called @q{subproperties} and reside inside
1412 properties. To tweak those, use commands in the form
1415 \override Stem #'details #'beamed-lengths = #'(4 4 3)
1418 @cindex internal documentation
1419 @cindex finding graphical objects
1420 @cindex graphical object descriptions
1423 @cindex internal documentation
1425 For many properties, regardless of the data type of the property, setting the
1426 property to false ( @code{##f} ) will result in turning it off, causing
1427 LilyPond to ignore that property entirely. This is particularly useful for
1428 turning off grob properties which may otherwise be causing problems.
1430 We demonstrate how to glean this information from the notation manual
1431 and the program reference.
1434 @node The tweak command
1435 @subsection The @code{\tweak} command
1440 In some cases, it is possible to take a short-cut for tuning
1441 graphical objects. For objects that are created directly from
1442 an item in the input file, you can use the @code{\tweak} command.
1445 @lilypond[relative=2,verbatim]
1450 \tweak #'duration-log #1
1453 -\tweak #'padding #8
1457 @cindex chord, modifying one note in
1459 But the main use of the @code{\tweak} command is to modify just
1460 one of a number of notation elements which start at the same musical
1461 moment, like the notes of a chord, or tuplet brackets which start
1464 For an introduction to the syntax and uses of the tweak command
1465 see @rlearning{Tweaking methods}.
1467 The @code{\tweak} command sets a property in the following object
1468 directly, without requiring the grob name or context to be
1469 specified. For this to work, it is necessary for the @code{\tweak}
1470 command to remain immediately adjacent to the object to which it is
1471 to apply after the input file has been converted to a music stream.
1472 This is often not the case, as many additional elements are inserted
1473 into the music stream implicitly. For example, when a note which is
1474 not part of a chord is processed, Lilypond implicitly inserts a
1475 @code{ChordEvent} event before the note, so separating the tweak
1476 from the note. However, if chord symbols are placed round the
1477 tweak and the note, the @code{\tweak} command comes after the
1478 @code{ChordEvent} in the music stream, so remaining adjacent to the
1479 note, and able to modify it.
1483 @lilypond[relative=2,verbatim,quote]
1484 <\tweak #'color #red c>4
1490 @lilypond[relative=2,verbatim,quote]
1491 \tweak #'color #red c4
1494 When several similar items are placed at the same musical moment,
1495 the @code{\override} command cannot be used to modify just one of
1496 them -- this is where the @code{\tweak} command must be used.
1497 Items which may appear more than once at the same musical moment
1498 include the following:
1500 @c TODO expand to include any further uses of \tweak
1502 @item note heads of notes inside a chord
1503 @item articulation signs on a single note
1504 @item ties between notes in a chord
1505 @item tuplet brackets starting at the same time
1508 @c TODO add examples of these
1511 and @code{\tweak} may be used to modify any single occurrence of
1514 Notably the @code{\tweak} command cannot be used to modify stems,
1515 beams or accidentals, since these are generated later by note heads,
1516 rather than by music elements in the input stream. Nor can a
1517 @code{\tweak} command be used to modify clefs or time signatures,
1518 since these become separated from any preceding @code{\tweak}
1519 command in the input stream by the automatic insertion of extra
1520 elements required to specify the context.
1522 But the @code{\tweak} command can be used as an alternative to
1523 the @code{\override} command to modify those notational elements
1524 that do not cause any additional implicit elements to be added
1525 before them in the music stream. For example, slurs may be
1526 modified in this way:
1528 @lilypond[verbatim,quote,relative=1]
1529 c-\tweak #'thickness #5 ( d e f)
1532 Also several @code{\tweak} commands may be placed before a
1533 notational element -- all affect it:
1535 @lilypond[verbatim,quote,relative=1]
1537 -\tweak #'style #'dashed-line
1538 -\tweak #'dash-fraction #0.2
1539 -\tweak #'thickness #3
1540 -\tweak #'color #red
1545 The music stream which is generated from a section of an input file,
1546 including any automatically inserted elements, may be examined,
1547 see @ref{Displaying music expressions}. This may be helpful in
1548 determining what may be modified by a @code{\tweak} command.
1553 @rlearning{Tweaking methods}.
1556 @ref{Displaying music expressions}.
1560 @cindex tweaks in a variable
1561 The @code{\tweak} command cannot be used inside a variable.
1563 @cindex tweaks in lyrics
1564 The @code{\tweak} commands cannot be used in @code{\lyricmode}.
1566 @cindex tweaking control points
1567 @cindex control points, tweaking
1569 The @code{\tweak} command cannot be used to modify the control
1570 points of just one of several ties in a chord, other than the first
1571 one encountered in the input file.
1573 @node set versus override
1574 @subsection @code{\set} vs. @code{\override}
1576 We have seen two methods of changing properties: @code{\set} and
1577 @code{\override}. There are actually two different kinds of
1580 Contexts can have properties, which are usually named in
1581 @code{studlyCaps}. They mostly control the translation from
1582 music to notation, eg. @code{localKeySignature} (for determining
1583 whether to print accidentals), @code{measurePosition} (for
1584 determining when to print a bar line). Context properties can
1585 change value over time while interpreting a piece of music;
1586 @code{measurePosition} is an obvious example of
1587 this. Context properties are modified with @code{\set}.
1589 There is a special type of context property: the element
1590 description. These properties are named in @code{StudlyCaps}
1591 (starting with capital letters). They contain the
1592 @q{default settings} for said graphical object as an
1593 association list. See @file{scm/@/define@/-grobs@/.scm}
1594 to see what kind of settings there are. Element descriptions
1595 may be modified with @code{\override}.
1597 @code{\override} is actually a shorthand;
1600 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1604 is more or less equivalent to
1606 @c leave this long line -gp
1608 \set @var{context}.@var{name} #'@var{property} = #(cons (cons '@var{property} @var{value}) <previous value of @var{context})
1611 The value of @code{context} (the alist) is used to initialize
1612 the properties of individual grobs. Grobs also have
1613 properties, named in Scheme style, with
1614 @code{dashed-words}. The values of grob properties change
1615 during the formatting process: formatting basically amounts
1616 to computing properties using callback functions.
1618 @code{fontSize} is a special property: it is equivalent to
1619 entering @code{\override ... #'font-size} for all pertinent
1620 objects. Since this is a common change, the special
1621 property (modified with @code{\set}) was created.
1624 @node Useful concepts and properties
1625 @section Useful concepts and properties
1630 * Direction and placement::
1631 * Distances and measurements::
1633 * Visibility of objects::
1635 * Rotating objects::
1639 @subsection Input modes
1641 The way in which the notation contained within an input file is
1642 interpreted is determined by the current input mode.
1646 This is activated with the @code{\chordmode} command, and causes
1647 input to be interpreted with the syntax of chord notation, see
1648 @ref{Chord notation}. Chords are rendered as notes on a staff.
1650 Chord mode is also activated with the @code{\chords} command.
1651 This also creates a new @code{ChordNames} context and
1652 causes the following input to be interpreted with the syntax of
1653 chord notation and rendered as chord names in the @code{ChordNames}
1654 context, see @ref{Printing chord names}.
1658 This is activated with the @code{\drummode} command, and causes
1659 input to be interpreted with the syntax of drum notation, see
1660 @ref{Basic percussion notation}.
1662 Drum mode is also activated with the @code{\drums} command.
1663 This also creates a new @code{DrumStaff} context and causes the
1664 following input to be interpreted with the syntax of drum notation
1665 and rendered as drum symbols on a drum staff, see @ref{Basic
1666 percussion notation}.
1668 @strong{Figure mode}
1670 This is activated with the @code{\figuremode} command, and causes
1671 input to be interpreted with the syntax of figured bass, see
1672 @ref{Entering figured bass}.
1674 Figure mode is also activated with the @code{\figures} command.
1675 This also creates a new @code{FiguredBass} context and causes the
1676 following input to be interpreted with the figured bass syntax
1677 and rendered as figured bass symbols in the @code{FiguredBass}
1678 context, see @ref{Introduction to figured bass}.
1680 @strong{Fret and tab modes}
1682 There are no special input modes for entering fret and tab symbols.
1684 To create tab diagrams, enter notes or chords in note mode and
1685 render them in a @code{TabStaff} context, see
1686 @ref{Default tablatures}.
1688 To create fret diagrams above a staff, you have two choices.
1689 You can either use the @code{FretBoards} context (see
1690 @ref{Automatic fret diagrams} or you can enter them as a markup
1691 above the notes using the @code{\fret-diagram} command (see
1692 @ref{Fret diagram markups}).
1694 @strong{Lyrics mode}
1696 This is activated with the @code{\lyricmode} command, and causes
1697 input to be interpreted as lyric syllables with optional durations
1698 and associated lyric modifiers, see @ref{Vocal music}.
1700 Lyric mode is also activated with the @code{\addlyrics} command.
1701 This also creates a new @code{Lyrics} context and an implicit
1702 @code{\lyricsto} command which associates the following lyrics
1703 with the preceding music.
1705 @strong{Markup mode}
1707 This is activated with the @code{\markup} command, and causes
1708 input to be interpreted with the syntax of markup, see
1709 @ref{Text markup commands}.
1711 @c silly work-around for texinfo broken-ness
1712 @c (@strong{Note...} causes a spurious cross-reference in Info)
1715 This is the default mode or it may be activated with the
1716 @code{\notemode} command. Input is interpreted as pitches,
1717 durations, markup, etc and typeset as musical notation on a staff.
1719 It is not normally necessary to specify note mode explicitly, but
1720 it may be useful to do so in certain situations, for example if you
1721 are in lyric mode, chord mode or any other mode and want to insert
1722 something that only can be done with note mode syntax.
1724 For example, to indicate dynamic markings for the verses of a
1725 choral pieces it is necessary to enter note mode to interpret
1728 @lilypond[verbatim,relative=2,quote]
1731 \notemode{\set stanza = \markup{ \dynamic f 1. } }
1735 \notemode{\set stanza = \markup{ \dynamic p 2. } }
1742 @node Direction and placement
1743 @subsection Direction and placement
1745 In typesetting music the direction and placement of many items is
1746 a matter of choice. For example, the stems of notes can
1747 be directed up or down; lyrics, dynamics, and other expressive
1748 marks may be placed above or below the staff; text may be aligned
1749 left, right or center; etc. Most of these choices may be left to
1750 be determined automatically by LilyPond, but in some cases it may
1751 be desirable to force a particular direction or placement.
1753 @strong{Default actions}
1755 By default some directions are always up or always down (e.g.
1756 dynamics or fermata), while other things can alternate between
1757 up or down based on the stem direction (like slurs or accents).
1759 @c TODO Add table showing these
1761 @strong{Context layout}
1763 Contexts are positioned in a system from top to bottom in the
1764 order in which they are encountered. Note, however, that a
1765 context will be created implicitly if a command is encountered
1766 when there is no suitable context available to contain it.
1768 @c TODO Add example ?
1770 The default order in which contexts are laid out can be changed,
1771 see @ref{Aligning contexts}
1773 @strong{Articulation direction indicators}
1775 When adding articulations to notes the direction indicator,
1776 @code{^} (meaning @qq{up}), @code{_} (meaning @qq{down}) or
1777 @code{-} (meaning @qq{use default direction}), can usually be
1778 omitted, in which case @code{-} is assumed. But a direction
1779 indicator is @strong{always} required before
1782 @item @code{\tweak} commands
1783 @item @code{\markup} commands
1784 @item @code{\tag} commands
1785 @item string markups, e.g. -"string"
1786 @item fingering instructions, e.g. @code{-1}
1787 @item articulation shortcuts, e.g. @code{-.}, @code{->}, @code{--}
1790 @strong{The direction property}
1792 The position or direction of many layout objects is controlled
1793 by the @code{direction} property.
1795 The value of the @code{direction} property may be
1796 set to @code{1}, meaning @qq{up} or @qq{above}, or to @code{-1},
1797 meaning @qq{down} or @qq{below}. The symbols @code{UP} and
1798 @code{DOWN} may be used instead of @code{1} and @code{-1}
1799 respectively. The default direction may be specified by setting
1800 @code{direction} to @code{0} or @code{CENTER}. Alternatively,
1801 in many cases predefined commands
1802 exist to specify the direction. These are all of the form
1805 @code{\xxxUp}, @code{xxxDown}, @code{xxxNeutral}
1808 where @code{xxxNeutral} means @qq{use the default direction}.
1809 See @rlearning{Within-staff objects}.
1811 In a few cases, arpeggio being the only common example, the value
1812 of the @code{direction} property specifies whether the object
1813 is to be placed to the right or left of the parent object. In
1814 this case @code{-1} or @code{LEFT} means @qq{to the left} and
1815 @code{1} or @code{RIGHT} means @qq{to the right}. @code{0}
1816 or @code{CENTER} means @qq{use the default} direction, as before.
1819 These all have side-axis set to #X
1820 AmbitusAccidental - direction has no effect
1822 StanzaNumber - not tried
1823 TrillPitchAccidental - not tried
1824 TrillPitchGroup - not tried
1829 @node Distances and measurements
1830 @subsection Distances and measurements
1832 @cindex distances, absolute
1833 @cindex distances, scaled
1840 Distances in LilyPond are of two types: absolute and scaled.
1842 Absolute distances are used for specifying margins, indents, and
1843 other page layout details, and are by default specified in
1844 millimeters. Distances may be specified in other units by
1845 following the quantity by @code{\mm}, @code{\cm},
1846 @code{\in}@tie{}(inches), or @code{\pt}@tie{}(points - 1/72 inch).
1847 Page layout is described in detail in @ref{Page formatting}.
1849 Scaled distances are always specified in units of the staff-space
1850 or, rarely, the half staff-space. The staff-space is the distance
1851 between two adjacent staff lines. The default value can be changed
1852 globally by setting the global staff size, or it can be overridden
1853 locally by changing the @code{staff-space} property of
1854 @code{StaffSymbol}. Scaled distances automatically scale with any
1855 change to the either the global staff size or the
1856 @code{staff-space} property of @code{StaffSymbol}, but fonts scale
1857 automatically only with changes to the global staff size.
1858 The global staff size thus enables the overall size of a rendered
1859 score to be easily varied. For the methods of setting the global
1860 staff size see @ref{Setting the staff size}.
1864 If just a section of a score needs to be rendered to a different
1865 scale, for example an ossia section or a footnote, the global staff
1866 size cannot simply be changed as this would affect the entire score.
1867 In such cases the change in size is made by overriding both the
1868 @code{staff-space} property of @code{StaffSymbol} and the size of
1869 the fonts. A Scheme function, @code{magstep}, is available to
1870 convert from a font size change to the equivalent change in
1871 @code{staff-space}. For an explanation and an example of its use,
1872 see @rlearning{Length and thickness of objects}.
1877 @rlearning{Length and thickness of objects}.
1880 @ref{Page formatting},
1881 @ref{Setting the staff size}.
1885 @subsection Spanners
1887 Many objects of musical notation extend over several notes or even
1888 several bars. Examples are slurs, beams, tuplet brackets, volta
1889 repeat brackets, crescendi, trills, and glissandi. Such objects
1890 are collectively called @qq{spanners}, and have special properties to control
1891 their appearance and behaviour. Some of these properties are common
1892 to all spanners; others are restricted to a sub-set of the spanners.
1894 All spanners support the @code{spanner-interface}. A few, esentially
1895 those that draw a straight line between the two objects, support in
1896 addition the @code{line-spanner-interface}.
1898 @unnumberedsubsubsec Using the @code{spanner-interface}
1900 This interface provides two properties that apply to several spanners.
1902 @strong{@i{The @code{minimum-length} property}}
1904 The minimum length of the spanner is specified by the
1905 @code{minimum-length} property. Increasing this usually has the
1906 necessary effect of increasing the spacing of the notes between the
1907 two end points. However, this override has no effect on
1908 many spanners, as their length is determined by other considerations.
1909 A few examples where it is effective are shown below.
1919 Works as long as callback is made:
1923 Works not at all for:
1932 @lilypond[verbatim,quote,relative=2]
1935 % increase the length of the tie
1936 -\tweak #'minimum-length #5
1940 @lilypond[verbatim,quote,relative=2]
1942 \compressFullBarRests
1944 % increase the length of the rest bar
1945 \once \override MultiMeasureRest #'minimum-length = #20
1950 @lilypond[verbatim,quote,relative=2]
1952 % increase the length of the hairpin
1953 \override Hairpin #'minimum-length = #20
1957 This override can also be used to increase the length of slurs and
1960 @lilypond[verbatim,quote,relative=2]
1963 -\tweak #'minimum-length #5
1968 -\tweak #'minimum-length #5
1972 For some layout objects, the @code{minimum-length} property becomes
1973 effective only if the @code{set-spacing-rods} procedure is called
1974 explicitly. To do this, the @code{springs-and-rods} property should
1975 be set to @code{ly:spanner::set-spacing-rods}. For example,
1976 the minimum length of a glissando has no effect unless the
1977 @code{springs-and-rods} property is set:
1979 @lilypond[verbatim,quote,relative=1]
1983 % not effective alone
1984 \once \override Glissando #'minimum-length = #20
1987 % effective only when both overrides are present
1988 \once \override Glissando #'minimum-length = #20
1989 \once \override Glissando #'springs-and-rods = #ly:spanner::set-spacing-rods
1993 The same is true of the @code{Beam} object:
1995 @lilypond[verbatim,quote,relative=1]
1996 % not effective alone
1997 \once \override Beam #'minimum-length = #20
2000 % effective only when both overrides are present
2001 \once \override Beam #'minimum-length = #20
2002 \once \override Beam #'springs-and-rods = #ly:spanner::set-spacing-rods
2006 @strong{@i{The @code{to-barline} property}}
2008 The second useful property of the @code{spanner-interface} is
2009 @code{to-barline}. By default this is true, causing hairpins and
2010 other spanners which are terminated on the first note of a measure to
2011 end instead on the immediately preceding bar line. If set to false,
2012 the spanner will extend beyond the bar line and end on the note
2015 @lilypond[verbatim,quote,relative=2]
2016 a \< a a a a \! a a a \break
2017 \override Hairpin #'to-barline = ##f
2018 a \< a a a a \! a a a
2021 This property is not effective for all spanners. For example,
2022 seting it to @code{#t} has no effect on slurs or phrasing slurs
2023 or on other spanners for which terminating on the bar line would
2026 @unnumberedsubsubsec Using the @code{line-spanner-interface}
2028 Objects which support the @code{line-spanner-interface} include
2031 @item @code{DynamicTextSpanner}
2032 @item @code{Glissando}
2033 @item @code{TextSpanner}
2034 @item @code{TrillSpanner}
2035 @item @code{VoiceFollower}
2038 The routine responsible for drawing the stencils for these spanners is
2039 @code{ly:line-interface::print}. This routine determines the
2040 exact location of the two end points and draws a line
2041 between them, in the style requested. The locations of the two
2042 end points of the spanner are computed on-the-fly, but it is
2043 possible to override their Y-coordinates. The
2044 properties which need to be specified are nested
2045 two levels down within the property hierarchy, but the syntax of
2046 the @code{\override} command is quite simple:
2048 @lilypond[relative=2,quote,verbatim]
2050 \once \override Glissando #'bound-details #'left #'Y = #3
2051 \once \override Glissando #'bound-details #'right #'Y = #-2
2055 The units for the @code{Y} property are @code{staff-space}s,
2056 with the center line of the staff being the zero point.
2057 For the glissando, this is the value for @code{Y} at the
2058 X-coordinate corresponding to the center point of each note head,
2059 if the line is imagined to be extended to there.
2061 If @code{Y} is not set, the value is computed from the vertical
2062 position of the corresponding attachment point of the spanner.
2064 In case of a line break, the values for the end points are
2065 specified by the @code{left-broken} and @code{right-broken}
2066 sub-lists of @code{bound-details}. For example:
2068 @lilypond[relative=2,ragged-right,verbatim,fragment]
2069 \override Glissando #'breakable = ##t
2070 \override Glissando #'bound-details #'right-broken #'Y = #-3
2071 c1 \glissando \break
2076 A number of further properties of the @code{left} and
2077 @code{right} sub-lists of the @code{bound-details} property
2078 may be modified in the same way as @code{Y}:
2082 This sets the Y-coordinate of the end point, in @code{staff-space}s
2083 offset from the staff center line. By default, it is the center of
2084 the bound object, so a glissando points to the vertical center of
2087 For horizontal spanners, such as text spanners and trill spanners,
2088 it is hardcoded to 0.
2091 This determines where the line starts and ends in the X-direction,
2092 relative to the bound object. So, a value of @code{-1} (or
2093 @code{LEFT}) makes the line start/end at the left side of the note
2094 head it is attached to.
2097 This is the absolute X-coordinate of the end point. It is usually
2098 computed on the fly, and overriding it has little useful effect.
2101 Line spanners may have symbols at the beginning or end, which is
2102 contained in this sub-property. This is for internal use; it is
2103 recommended that @code{text} be used instead.
2106 This is a markup that is evaluated to yield the stencil. It is used
2107 to put @i{cresc.}, @i{tr} and other text on horizontal spanners.
2109 @lilypond[quote,ragged-right,fragment,relative=2,verbatim]
2110 \override TextSpanner #'bound-details #'left #'text
2111 = \markup { \small \bold Slower }
2112 c2\startTextSpan b c a\stopTextSpan
2115 @item stencil-align-dir-y
2116 @item stencil-offset
2117 Without setting one of these, the stencil is simply put at the
2118 end-point, centered on the line, as defined by the @code{X} and
2119 @code{Y} sub-properties. Setting either @code{stencil-align-dir-y}
2120 or @code{stencil-offset} will move the symbol at the edge vertically
2121 relative to the end point of the line:
2123 @lilypond[relative=1,fragment,verbatim]
2124 \override TextSpanner #'bound-details
2125 #'left #'stencil-align-dir-y = #-2
2126 \override TextSpanner #'bound-details
2127 #'right #'stencil-align-dir-y = #UP
2129 \override TextSpanner #'bound-details
2130 #'left #'text = #"ggg"
2131 \override TextSpanner #'bound-details
2132 #'right #'text = #"hhh"
2133 c4^\startTextSpan c c c \stopTextSpan
2136 Note that negative values move the text @emph{up}, contrary to the
2137 effect that might be expected, as a value of @code{-1} or
2138 @code{DOWN} means align the @emph{bottom} edge of the text with
2139 the spanner line. A value of @code{1} or @code{UP} aligns
2140 the top edge of the text with the spanner line.
2143 Setting this sub-property to @code{#t} produces an arrowhead at the
2147 This sub-property controls the space between the specified
2148 end point of the line and the actual end. Without padding, a
2149 glissando would start and end in the center of each note head.
2153 The music function @code{\endSpanners} terminates the spanner
2154 which starts on the immediately following note prematurely. It
2155 is terminated after exactly one note, or at the following bar line
2156 if @code{to-barline} is true and a bar line occurs before the next
2159 @lilypond[verbatim,quote,ragged-right,relative=2,fragment]
2161 c2 \startTextSpan c2 c2
2166 When using @code{\endSpanners} it is not necessary to close
2167 \startTextSpan with \stopTextSpan, nor is it necessary to close
2168 hairpins with @code{\!}.
2174 Internals Reference: @rinternals{TextSpanner},
2175 @rinternals{Glissando}, @rinternals{VoiceFollower},
2176 @rinternals{TrillSpanner},
2177 @rinternals{line-spanner-interface}.
2180 @node Visibility of objects
2181 @subsection Visibility of objects
2183 @cindex objects, visibility of
2184 @cindex grobs, visibility of
2185 @cindex visibility of objects
2187 There are four main ways in which the visibility of layout objects
2188 can be controlled: their stencil can be removed, they can be made
2189 transparent, they can be colored white, or their
2190 @code{break-visibility} property can be overridden. The first
2191 three apply to all layout objects; the last to just a few -- the
2192 @emph{breakable} objects. The Learning Manual introduces these
2193 four techniques, see @rlearning{Visibility and color of objects}.
2195 There are also a few other techniques which are specific to
2196 certain layout objects. These are covered under Special
2200 * Removing the stencil::
2201 * Making objects transparent::
2202 * Painting objects white::
2203 * Using break-visibility::
2204 * Special considerations::
2208 @node Removing the stencil
2209 @unnumberedsubsubsec Removing the stencil
2211 @cindex stencil, removing
2213 Every layout object has a stencil property. By default this is set
2214 to the specific function which draws that object. If this property
2215 is overridden to @code{#f} no function will be called and the object
2216 will not be drawn. The default action can be recovered with
2219 @lilypond[quote,verbatim,relative=1]
2221 \override Score.BarLine #'stencil = ##f
2223 \revert Score.BarLine #'stencil
2227 @node Making objects transparent
2228 @unnumberedsubsubsec Making objects transparent
2230 @cindex transparent, making objects
2232 Every layout object has a transparent property which by default is
2233 set to @code{#f}. If set to @code{#t} the object still occupies
2234 space but is made invisible.
2236 @lilypond[quote,verbatim,relative=2]
2238 \once \override NoteHead #'transparent = ##t
2242 @node Painting objects white
2243 @unnumberedsubsubsec Painting objects white
2245 @cindex objects, coloring
2246 @cindex coloring objects
2248 @cindex printing order
2249 @cindex overwriting objects
2250 @cindex objects, overwriting
2251 @cindex grobs, overwriting
2253 Every layout object has a color property which by default is set
2254 to @code{black}. If this is overridden to @code{white} the object
2255 will be indistinguishable from the white background. However,
2256 if the object crosses other objects the color of the crossing
2257 points will be determined by the order in which they are drawn,
2258 and this may leave a ghostly image of the white object, as shown
2261 @lilypond[quote,verbatim,relative=2]
2262 \override Staff.Clef #'color = #white
2266 This may be avoided by changing the order of printing the objects.
2267 All layout objects have a @code{layer} property which should be set
2268 to an integer. Objects with the lowest value of @code{layer} are
2269 drawn first, then objects with progressively higher values are drawn,
2270 so objects with higher values overwrite objects with lower values.
2271 By default most objects are assigned a @code{layer} value of
2272 @code{1}, although a few objects, including @code{StaffSymbol} and
2273 @code{BarLine}, are assigned a value of @code{0}. The order of
2274 printing objects with the same value of @code{layer} is indeterminate.
2276 In the example above the white clef, with a default @code{layer}
2277 value of @code{1}, is drawn after the staff lines (default
2278 @code{layer} value @code{0}), so overwriting them. To change this,
2279 the @code{Clef} object must be given in a lower value of
2280 @code{layer}, say @code{-1}, so that it is drawn earlier:
2282 @lilypond[quote,verbatim,relative=2]
2283 \override Staff.Clef #'color = #white
2284 \override Staff.Clef #'layer = #-1
2288 @node Using break-visibility
2289 @unnumberedsubsubsec Using break-visibility
2291 @c TODO Add making other objects breakable
2293 @cindex break-visibility
2295 Most layout objects are printed only once, but some like
2296 bar lines, clefs, time signatures and key signatures, may need
2297 to be printed twice when a line break occurs -- once at the end
2298 of the line and again at the start of the next line. Such
2299 objects are called @emph{breakable}, and have a property, the
2300 @code{break-visibility} property to control their visibility
2301 at the three positions in which they may appear -- at the
2302 start of a line, within a line if they are changed, and at the
2303 end of a line if a change takes place there.
2305 For example, the time signature
2306 by default will be printed at the start of the first line, but
2307 nowhere else unless it changes, when it will be printed at the
2308 point at which the change occurs. If this change occurs at the
2309 end of a line the new time signature will be printed at the start
2310 of the next line and a cautionary time signature will be printed
2311 at the end of the previous line as well.
2313 This behaviour is controlled by the @code{break-visibility}
2314 property, which is explained in
2315 @c Leave this ref on a newline - formats incorrectly otherwise -td
2316 @rlearning{Visibility and color of objects}. This property takes
2317 a vector of three booleans which, in order, determine whether the
2318 object is printed at the end of, within the body of, or at the
2319 beginning of a line. Or to be more precise, before a line break,
2320 where there is no line break, or after a line break.
2322 Alternatively, seven of the eight combinations may be specified
2323 by pre-defined functions, defined in @file{scm/output-lib.scm},
2324 where the last three columns indicate whether the layout objects
2325 will be visible in the positions shown at the head of the columns:
2327 @multitable @columnfractions .40 .15 .1 .1 .1
2328 @c TODO check these more carefully
2329 @headitem Function @tab Vector @tab Before @tab At no @tab After
2330 @headitem form @tab form @tab break @tab break @tab break
2332 @item @code{all-invisible} @tab @code{'#(#f #f #f)} @ @ @tab no @tab no @tab no
2333 @item @code{begin-of-line-visible} @tab @code{'#(#f #f #t)} @tab no @tab no @tab yes
2334 @item @code{end-of-line-visible} @tab @code{'#(#t #f #f)} @tab yes @tab no @tab no
2335 @item @code{all-visible} @tab @code{'#(#t #t #t)} @tab yes @tab yes @tab yes
2336 @c The center-visible function is not defined
2337 @c @item @code{center-visible} @tab @code{'#(#f #t #f)} @tab no @tab yes @tab no
2338 @item @code{begin-of-line-invisible} @tab @code{'#(#t #t #f)} @tab yes @tab yes @tab no
2339 @item @code{end-of-line-invisible} @tab @code{'#(#f #t #t)} @tab no @tab yes @tab yes
2340 @item @code{center-invisible} @tab @code{'#(#t #f #t)} @tab yes @tab no @tab yes
2343 The @code{center-visible} function is not pre-defined.
2345 The default settings of @code{break-visibility} depend on the
2346 layout object. The following table shows all the layout objects
2347 of interest which are affected by @code{break-visibility} and the
2348 default setting of this property:
2350 @multitable @columnfractions .3 .3 .4
2352 @headitem Layout object @tab Usual context @tab Default setting
2354 @c omit Ambitus as it appears not to be affected by break-visibility -td
2355 @c @item @code{Ambitus} @tab as specified @tab @code{begin-of-line-visible}
2356 @item @code{BarLine} @tab @code{Score} @tab calculated
2357 @item @code{BarNumber} @tab @code{Score} @tab @code{begin-of-line-visible}
2358 @c omit the following item until it can be explained -td
2359 @c @item @code{BreakAlignGroup} @tab @code{Score} @tab calculated
2360 @item @code{BreathingSign} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2361 @item @code{Clef} @tab @code{Staff} @tab @code{begin-of-line-visible}
2362 @item @code{Custos} @tab @code{Staff} @tab @code{end-of-line-visible}
2363 @item @code{DoublePercentRepeat} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2364 @c omit KeyCancellation until it can be explained -td
2365 @c @item @code{KeyCancellation} @tab ?? @tab @code{begin-of-line-invisible}
2366 @item @code{KeySignature} @tab @code{Staff} @tab @code{begin-of-line-visible}
2367 @c omit LeftEdge until it can be explained -td
2368 @c @item @code{LeftEdge} @tab @code{Score} @tab @code{center-invisible}
2369 @item @code{OctavateEight} @tab @code{Staff} @tab @code{begin-of-line-visible}
2370 @item @code{RehearsalMark} @tab @code{Score} @tab @code{end-of-line-invisible}
2371 @item @code{TimeSignature} @tab @code{Staff} @tab @code{all-visible}
2375 The example below shows the use of the vector form to control the
2376 visibility of barlines:
2378 @lilypond[quote,verbatim,relative=1,ragged-right]
2381 % Remove bar line at the end of the current line
2382 \once \override Score.BarLine #'break-visibility = #'#(#f #t #t)
2388 Although all three components of the vector used to override
2389 @code{break-visibility} must be present, not all of them are
2390 effective with every layout object, and some combinations may
2391 even give errors. The following limitations apply:
2394 @item Bar lines cannot be printed at start of line.
2395 @item A bar number cannot be printed at the start of the first
2396 line unless it is set to be different from 1.
2397 @item Clef -- see below
2398 @item Double percent repeats are either all printed or all
2399 suppressed. Use begin-of line-invisible to print and
2400 all-invisible to suppress.
2401 @item Key signature -- see below
2402 @item OctavateEight -- see below
2405 @node Special considerations
2406 @unnumberedsubsubsec Special considerations
2408 @strong{@emph{Visibility following explicit changes}}
2410 @cindex key signature, visibility following explicit change
2411 @cindex explicitKeySignatureVisibility
2412 @cindex clef, visibility following explicit change
2413 @cindex explicitClefVisibility
2415 The @code{break-visibility} property controls the visibility of
2416 key signatures and changes of clef only at the start of lines,
2417 i.e. after a break. It has no effect on the visibility of the
2418 key signature or clef following an explicit key change or an
2419 explicit clef change within or at the end of a line. In the
2420 following example the key signature following the explicit change
2421 to B-flat major is still visible, even though @code{all-invisible}
2424 @lilypond[quote,verbatim,relative=1,ragged-right]
2427 % Try to remove all key signatures
2428 \override Staff.KeySignature #'break-visibility = #all-invisible
2436 The visibility of such explicit key signature and clef changes is
2437 controlled by the @code{explicitKeySignatureVisibility} and
2438 @code{explicitClefVisibility} properties. These are the equivalent
2439 of the @code{break-visibility} property and both take a vector of
2440 three booleans or the predefined functions listed above, exactly like
2441 @code{break-visibility}. Both are properties of the Staff context,
2442 not the layout objects themselves, and so they are set using the
2443 @code{\set} command. Both are set by default to @code{all-visible}.
2444 These properties control only the visibility of key signatures and
2445 clefs resulting from explicit changes and do not affect key
2446 signatures and clefs at the beginning of lines;
2447 @code{break-visibility} must still be overridden in the appropriate
2448 object to remove these.
2450 @lilypond[quote,verbatim,relative=1,ragged-right]
2453 \set Staff.explicitKeySignatureVisibility = #all-invisible
2454 \override Staff.KeySignature #'break-visibility = #all-invisible
2461 @strong{@emph{Visibility of cautionary accidentals}}
2463 To remove the cautionary accidentals printed at an explicit key
2464 change, set the Staff context property @code{printKeyCancellation}
2467 @lilypond[quote,verbatim,relative=1,ragged-right]
2470 \set Staff.explicitKeySignatureVisibility = #all-invisible
2471 \set Staff.printKeyCancellation = ##f
2472 \override Staff.KeySignature #'break-visibility = #all-invisible
2479 With these overrides only the accidentals before the notes remain
2480 to indicate the change of key.
2482 @c TODO Add visibility of cautionary accidentals before notes
2484 @strong{@emph{Automatic bars}}
2486 @cindex automaticBars
2487 @cindex bar lines, suppressing
2489 As a special case, the printing of bar lines can also be turned off
2490 by setting the @code{automaticBars} property in the Score context.
2491 If set to @code{#f}, bar lines will not be printed automatically;
2492 they must be explicitly created with a @code{\bar} command. Unlike
2493 the @code{\cadenzaOn} predefined command, measures are still counted.
2494 Bar generation will resume according to that count if this property
2495 is later set to @code{#t}. When set to @code{#f}, line breaks can
2496 occur only at explicit @code{\bar} commands.
2500 @strong{@emph{Octavated clefs}}
2502 @cindex octavated clefs, visibility of
2503 @cindex visibility of octavated clefs
2504 @cindex clefs, visibility of octavation
2506 The small octavation symbol on octavated clefs is produced by the
2507 @code{OctavateEight} layout object. Its visibility is controlled
2508 independently from that of the @code{Clef} object, so it is
2509 necessary to apply any required @code{break-visibility} overrides
2510 to both the @code{Clef} and the @code{OctavateEight} layout objects
2511 to fully suppress such clef symbols at the start of each line.
2513 For explicit clef changes, the @code{explicitClefVisibility}
2514 property controls both the clef symbol and any octavation symbol
2520 @rlearning{Visibility and color of objects}
2524 @subsection Line styles
2526 Some performance indications, e.g., @i{rallentando} and
2527 @i{accelerando} and @i{trills} are written as text and are
2528 extended over many measures with lines, sometimes dotted or wavy.
2530 These all use the same routines as the glissando for drawing the
2531 texts and the lines, and tuning their behavior is therefore also
2532 done in the same way. It is done with a spanner, and the routine
2533 responsible for drawing the spanners is
2534 @code{ly:line-interface::print}. This routine determines the
2535 exact location of the two @i{span points} and draws a line
2536 between them, in the style requested.
2538 Here is an example showing the different line styles available,
2539 and how to tune them.
2541 @lilypond[relative=2,ragged-right,verbatim,fragment]
2543 \once \override Glissando #'style = #'dashed-line
2545 \override Glissando #'style = #'dotted-line
2547 \override Glissando #'style = #'zigzag
2549 \override Glissando #'style = #'trill
2553 The locations of the end-points of the spanner are computed
2554 on-the-fly for every graphic object, but it is possible to
2558 @lilypond[relative=2,ragged-right,verbatim,fragment]
2560 \once \override Glissando #'bound-details #'right #'Y = #-2
2564 The value for @code{Y} is set to @code{-2} for the right end
2565 point. The left side may be similarly adjusted by specifying
2566 @code{left} instead of @code{right}.
2568 If @code{Y} is not set, the value is computed from the vertical
2569 position of the left and right attachment points of the spanner.
2571 Other adjustments of spanners are possible, for details, see
2574 @node Rotating objects
2575 @subsection Rotating objects
2577 Both layout objects and elements of markup text can be rotated by
2578 any angle about any point, but the method of doing so differs.
2581 * Rotating layout objects::
2585 @node Rotating layout objects
2586 @unnumberedsubsubsec Rotating layout objects
2588 @cindex rotating objects
2589 @cindex objects, rotating
2591 All layout objects which support the @code{grob-interface} can be
2592 rotated by setting their @code{rotation} property. This takes a
2593 list of three items: the angle of rotation counter-clockwise,
2594 and the x and y coordinates of the point relative to the object's
2595 reference point about which the rotation is to be performed. The
2596 angle of rotation is specified in degrees and the coordinates in
2599 The angle of rotation and the coordinates of the rotation point must
2600 be determined by trial and error.
2602 @cindex hairpins, angled
2603 @cindex angled hairpins
2605 There are only a few situations where the rotation of layout
2606 objects is useful; the following example shows one situation where
2609 @lilypond[quote,verbatim,relative=1]
2611 \override Hairpin #'rotation = #'(20 -1 0)
2615 @node Rotating markup
2616 @unnumberedsubsubsec Rotating markup
2618 All markup text can be rotated to lie at any angle by prefixing it
2619 with the @code{\rotate} command. The command takes two arguments:
2620 the angle of rotation in degrees counter-clockwise and the text to
2621 be rotated. The extents of the text are not rotated: they take
2622 their values from the extremes of the x and y coordinates of the
2623 rotated text. In the following example the
2624 @code{outside-staff-priority} property for text is set to @code{#f}
2625 to disable the automatic collision avoidance, which would push some
2626 of the text too high.
2628 @lilypond[quote,verbatim,relative=1]
2629 \override TextScript #'outside-staff-priority = ##f
2630 g4^\markup { \rotate #30 "a G" }
2631 b^\markup { \rotate #30 "a B" }
2632 des^\markup { \rotate #30 "a D-Flat" }
2633 fis^\markup { \rotate #30 "an F-Sharp" }
2636 @node Advanced tweaks
2637 @section Advanced tweaks
2640 * Aligning objects::
2641 * Vertical grouping of grobs::
2642 * Modifying stencils::
2643 * Modifying shapes::
2646 @node Aligning objects
2647 @subsection Aligning objects
2649 Graphical objects which support the @code{self-alignment-interface} and/or
2650 the @code{side-position-interface} can be
2651 aligned to a previously placed object in a variety of ways. For a list of these objects, see
2652 @rinternals{self-alignment-interface} and @rinternals{side-position-interface}.
2654 All graphical objects have a reference point, a horizontal extent and a
2655 vertical extent. The horizontal extent is a pair of numbers
2656 giving the displacements from the reference point of the left and
2657 right edges, displacements to the left being negative. The
2658 vertical extent is a pair of numbers giving the displacement from
2659 the reference point to the bottom and top edges, displacements down
2662 An object's position on a staff is given by the values of the
2663 @code{X-offset} and @code{Y-offset} properties. The value of
2664 @code{X-offset} gives the displacement from the x coordinate of
2665 the reference point of the parent object, and the value of
2666 @code{Y-offset} gives the displacement from the center line of the
2667 staff. The values of @code{X-offset} and
2668 @code{Y-offset} may be set directly or may be set to be calculated
2669 by procedures in order to achieve alignment with the parent object
2672 @warning{Many objects have special positioning considerations which
2673 cause any setting of @code{X-offset} or @code{Y-offset} to be
2674 ignored or modified, even though the object supports the
2675 @code{self-alignment-interface}.}
2677 For example, an accidental can be repositioned
2678 vertically by setting @code{Y-offset} but any changes to
2679 @code{X-offset} have no effect.
2681 Rehearsal marks may be aligned with
2682 breakable objects such as bar lines, clef symbols, time signature
2683 symbols and key signatures. There are special properties to be
2684 found in the @code{break-aligned-interface} for positioning rehearsal
2685 marks on such objects.
2688 * Setting @code{X-offset} and @code{Y-offset} directly::
2689 * Using the @code{side-position-interface}::
2690 * Using the @code{self-alignment-interface}::
2691 * Using the @code{break-aligned-interface}::
2694 @node Setting @code{X-offset} and @code{Y-offset} directly
2695 @unnumberedsubsubsec Setting @code{X-offset} and @code{Y-offset} directly
2697 Numerical values may be given to the @code{X-offset} and @code{Y-offset}
2698 properties of many objects. The following example shows three
2699 notes with the default fingering position and the positions with @code{X-offset}
2700 and @code{Y-offset} modified.
2702 @lilypond[verbatim,quote,relative=2]
2705 -\tweak #'X-offset #0
2706 -\tweak #'Y-offset #0
2709 -\tweak #'X-offset #-1
2710 -\tweak #'Y-offset #1
2716 @node Using the @code{side-position-interface}
2717 @unnumberedsubsubsec Using the @code{side-position-interface}
2719 An object which supports the @code{side-position-interface} can be
2720 placed next to its parent object so that
2721 the specified edges of the two objects touch. The object may be
2722 placed above, below, to the right or to the left of the parent.
2723 The parent cannot be specified; it is determined by the order of
2724 elements in the input stream. Most objects have the associated
2725 note head as their parent.
2727 The values of the @code{side-axis} and @code{direction} properties
2728 determine where the object is to be placed, as follows:
2730 @c TODO add an example of each to the table
2732 @multitable @columnfractions .3 .3 .3
2733 @headitem @code{side-axis} @tab @code{direction} @tab
2734 @headitem property @tab property @tab Placement
2736 @item @code{0} @tab @code{-1} @tab left
2737 @item @code{0} @tab @code{1} @tab right
2738 @item @code{1} @tab @code{-1} @tab below
2739 @item @code{1} @tab @code{1} @tab above
2743 When @code{side-axis} is @code{0}, @code{X-offset} should be set to
2744 the procedure @code{ly:side-position-interface::x-aligned-side}.
2745 This procedure will return the correct value of @code{X-offset} to
2746 place the object to the left or right side of the parent according
2747 to value of @code{direction}.
2749 When @code{side-axis} is @code{1}, @code{Y-offset} should be set to
2750 the procedure @code{ly:side-position-interface::y-aligned-side}.
2751 This procedure will return the correct value of @code{Y-offset} to
2752 place the object to the top or bottom of the parent according
2753 to value of @code{direction}.
2755 @c TODO Add examples
2757 @node Using the @code{self-alignment-interface}
2758 @unnumberedsubsubsec Using the @code{self-alignment-interface}
2760 @emph{Self-aligning objects horizontally}
2762 The horizontal alignment of an object which supports the
2763 @code{self-alignment-interface} is controlled by the value of
2764 the @code{self-alignment-X} property, provided the object's
2765 @code{X-offset} property is set to
2766 @code{ly:self-alignment-interface::x-aligned-on-self}.
2767 @code{self-alignment-X} may be given any
2768 real value, in units of half the total X extent of the
2769 object. Negative values move the object to the right, positive
2770 to the left. A value of @code{0} centers the object on the
2771 reference point of its parent, a value of @code{-1} aligns the
2772 left edge of the object on the reference point of its parent,
2773 and a value of @code{1} aligns the right edge of the object on the
2774 reference point of its parent. The symbols @code{LEFT},
2775 @code{CENTER} and @code{RIGHT} may be used instead of the values
2776 @code{-1, 0, 1} respectively.
2778 Normally the @code{\override} command would be used to modify the
2779 value of @code{self-alignment-X}, but the @code{\tweak} command
2780 can be used to separately align several annotations on a single
2783 @lilypond[quote,verbatim,relative=1]
2785 -\tweak #'self-alignment-X #-1
2787 -\tweak #'self-alignment-X #0
2789 -\tweak #'self-alignment-X #RIGHT
2791 -\tweak #'self-alignment-X #-2.5
2792 ^"aligned further to the right"
2795 @emph{Self-aligning objects vertically}
2797 Objects may be aligned vertically in an analogous way to aligning
2798 them horizontally if the @code{Y-offset} property is set to
2799 @code{ly:self-alignment-interface::y-aligned-on-self}. However,
2800 other mechanisms are often involved in vertical alignment: the
2801 value of @code{Y-offset} is just one variable taken into account.
2802 This may make adjusting the value of some objects tricky.
2803 The units are just half the vertical extent of the object, which
2804 is usually quite small, so quite large numbers may be required.
2805 A value of @code{-1} aligns the lower edge of the object with
2806 the reference point of the parent object, a value of @code{0}
2807 aligns the center of the object with the reference point of the
2808 parent, and a value of @code{1} aligns the top edge of the object
2809 with the reference point of the parent. The symbols @code{DOWN},
2810 @code{CENTER}, @code{UP} may be substituted for @code{-1, 0, 1}
2813 @emph{Self-aligning objects in both directions}
2815 By setting both @code{X-offset} and @code{Y-offset}, an object may
2816 be aligned in both directions simultaneously.
2818 The following example shows how to adjust a fingering mark so
2819 that it nestles close to the note head.
2821 @lilypond[quote,verbatim,relative=2]
2823 -\tweak #'self-alignment-X #0.5 % move horizontally left
2824 -\tweak #'Y-offset #ly:self-alignment-interface::y-aligned-on-self
2825 -\tweak #'self-alignment-Y #-1 % move vertically up
2830 @unnumberedsubsubsec Using the @code{aligned-on-parent} procedures
2832 @c Cannot document as they do not seem to operate consistently on all objects -td
2833 @c TODO investigate further
2835 The @code{aligned-on-parent} procedures are used in the same way
2836 as the @code{aligned-on-self} procedures, they difference being
2837 that they permit an object to be aligned with the @emph{edges} of
2838 the parent rather than the parent's reference point. The following
2839 example shows the difference:
2843 @lilypond[verbatim,quote]
2849 @unnumberedsubsubsec Using the @code{centered-on-parent} procedures
2851 @c Cannot document as they do not seem to operate consistently on all objects -td
2852 @c TODO investigate further
2856 @c TODO The align-interface, BassFigureAlignment and VerticalAlignment
2858 @node Using the @code{break-aligned-interface}
2859 @unnumberedsubsubsec Using the @code{break-aligned-interface}
2861 Rehearsal marks may be aligned with notation objects other
2862 than bar lines. These objects include @code{ambitus},
2863 @code{breathing-sign}, @code{clef}, @code{custos}, @code{staff-bar},
2864 @code{left-edge}, @code{key-cancellation}, @code{key-signature}, and
2865 @code{time-signature}.
2867 By default, rehearsal marks will be horizontally centered above the
2870 @lilypond[verbatim,quote,relative=1]
2872 % the RehearsalMark will be centered above the Clef
2873 \override Score.RehearsalMark #'break-align-symbols = #'(clef)
2878 % the RehearsalMark will be centered above the TimeSignature
2879 \override Score.RehearsalMark #'break-align-symbols = #'(time-signature)
2887 The alignment of the rehearsal mark relative to the notation object
2888 can be changed, as shown in the following example. In a score with
2889 multiple staves, this setting should be done for all the staves.
2891 @lilypond[verbatim,quote,relative=1]
2892 % The RehearsalMark will be centered above the KeySignature
2893 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
2899 % The RehearsalMark will be aligned with the left edge of the KeySignature
2900 \once \override Score.KeySignature #'break-align-anchor-alignment = #LEFT
2904 % The RehearsalMark will be aligned with the right edge of the KeySignature
2905 \once \override Score.KeySignature #'break-align-anchor-alignment = #RIGHT
2911 The rehearsal mark can also be offset to the right or left of the left edge
2912 by an arbitrary amount. The units are staff-spaces:
2914 @lilypond[verbatim,quote,relative=1]
2915 % The RehearsalMark will be aligned with the left edge of the KeySignature
2916 % and then shifted right by 3.5 staff-spaces
2917 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
2918 \once \override Score.KeySignature #'break-align-anchor = #3.5
2922 % The RehearsalMark will be aligned with the left edge of the KeySignature
2923 % and then shifted left by 2 staff-spaces
2924 \once \override Score.KeySignature #'break-align-anchor = #-2
2932 @node Vertical grouping of grobs
2933 @subsection Vertical grouping of grobs
2935 @c FIXME Expand this section
2937 The VerticalAlignment and VerticalAxisGroup grobs work together.
2938 VerticalAxisGroup groups together different grobs like Staff, Lyrics,
2939 etc. VerticalAlignment then vertically aligns the different grobs
2940 grouped together by VerticalAxisGroup. There is usually only one
2941 VerticalAlignment per score but every Staff, Lyrics, etc. has its own
2945 @node Modifying stencils
2946 @subsection Modifying stencils
2948 All layout objects have a @code{stencil} property which is part of
2949 the @code{grob-interface}. By default, this property is usually
2950 set to a function specific to the object that is tailor-made to
2951 render the symbol which represents it in the output. For example,
2952 the standard setting for the @code{stencil} property of the
2953 @code{MultiMeasureRest} object is @code{ly:multi-measure-rest::print}.
2955 The standard symbol for any object can be replaced by modifying the
2956 @code{stencil} property to reference a different, specially-written,
2957 procedure. This requires a high level of knowledge of the internal
2958 workings of LilyPond, but there is an easier way which can often
2959 produce adequate results.
2961 This is to set the @code{stencil} property to the procedure which
2962 prints text -- @code{ly:text-interface::print} -- and to add a
2963 @code{text} property to the object which is set to contain the
2964 markup text which produces the required symbol. Due to the
2965 flexibility of markup, much can be achieved -- see in particular
2966 @ref{Graphic notation inside markup}.
2968 The following example demonstrates this by changing the note head
2969 symbol to a cross within a circle.
2971 @lilypond[verbatim,quote]
2973 \once \override NoteHead #'stencil = #ly:text-interface::print
2974 \once \override NoteHead #'text = \markup {
2976 \halign #-0.7 \draw-circle #0.85 #0.2 ##f
2977 \musicglyph #"noteheads.s2cross"
2985 Any of the glyphs in the feta Font can be supplied to the
2986 @code{\musicglyph} markup command -- see @ref{The Feta font}.
2988 @c TODO Add inserting eps files or ref to later
2990 @c TODO Add inserting Postscript or ref to later
2995 @ref{Graphic notation inside markup},
2996 @ref{Formatting text},
2997 @ref{Text markup commands},
2998 @ref{The Feta font}.
3001 @node Modifying shapes
3002 @subsection Modifying shapes
3005 * Modifying ties and slurs::
3008 @node Modifying ties and slurs
3009 @unnumberedsubsubsec Modifying ties and slurs
3011 Ties, slurs and phrasing slurs are drawn as third-order Bézier
3012 curves. If the shape of the tie or slur which is calculated
3013 automatically is not optimum, the shape may be modified manually by
3014 explicitly specifying the four control points required to define
3015 a third-order Bézier curve.
3017 Third-order or cubic Bézier curves are defined by four control
3018 points. The first and fourth control points are precisely the
3019 starting and ending points of the curve. The intermediate two
3020 control points define the shape. Animations showing how the curve
3021 is drawn can be found on the web, but the following description
3022 may be helpful. The curve starts from the first control point
3023 heading directly towards the second, gradually bending over to
3024 head towards the third and continuing to bend over to head towards
3025 the fourth, arriving there travelling directly from the third
3026 control point. The curve is entirely contained in the
3027 quadrilateral defined by the four control points.
3029 Here is an example of a case where the tie is not optimum, and
3030 where @code{\tieDown} would not help.
3032 @lilypond[verbatim,quote,relative=1]
3036 { r4 <g c,> <g c,> <g c,> }
3040 One way of improving this tie is to manually modify its control
3043 The coordinates of the Bézier control points are specified in units
3044 of staff-spaces. The X@tie{}coordinate is relative to the reference
3045 point of the note to which the tie or slur is attached, and the
3046 Y@tie{}coordinate is relative to the staff center line. The
3047 coordinates are entered as a list of four pairs of decimal numbers
3048 (reals). One approach is to estimate the coordinates of the two
3049 end points, and then guess the two intermediate points. The optimum
3050 values are then found by trial and error.
3052 It is useful to remember that a symmetric curve requires symmetric
3053 control points, and that Bézier curves have the useful property that
3054 transformations of the curve such as translation, rotation and
3055 scaling can be achieved by applying the same transformation to the
3056 curve's control points.
3058 For the example above the following override gives a satisfactory
3061 @lilypond[verbatim,quote,relative=1]
3064 #'control-points = #'((1 . -1) (3 . 0.6) (12.5 . 0.6) (14.5 . -1))
3067 { r4 <g c,> <g c,> <g c,>4 }
3073 It is not possible to modify shapes of ties or slurs by changing
3074 the @code{control-points} property if there are more than one at
3075 the same musical moment, not even by using the @code{\tweak}
3080 @node Discussion of specific tweaks
3081 @section Discussion of specific tweaks
3083 @c TODO What should go in here?