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"
537 @node Changing context default settings
538 @subsection Changing context default settings
540 The adjustments of the previous subsections (
541 @ref{The set command}, @ref{Modifying context plug-ins}, and
542 @ref{Overview of modifying properties}) can also be entered
543 separately from the music in the @code{\layout} block,
552 \override Stem #'thickness = #4.0
553 \remove "Time_signature_engraver"
558 The @code{\Staff} command brings in the existing definition of the
559 staff context so that it can be modified.
564 \override Stem #'thickness = #4.0
565 \remove "Time_signature_engraver"
569 affect all staves in the score. Other contexts can be modified
572 The @code{\set} keyword is optional within the @code{\layout} block, so
588 It is not possible to collect context changes in a variable and apply
589 them to a @code{\context} definition by referring to that variable.
591 The @code{\RemoveEmptyStaffContext} will overwrite your current
592 @code{\Staff} settings. If you wish to change the defaults for a
593 staff which uses @code{\RemoveEmptyStaffContext}, you must do so
594 after calling @code{\RemoveEmptyStaffContext}, ie
599 \RemoveEmptyStaffContext
601 \override Stem #'thickness = #4.0
606 TODO: add \with in here.
610 @node Defining new contexts
611 @subsection Defining new contexts
613 Specific contexts, like @code{Staff} and @code{Voice}, are made of
614 simple building blocks. It is possible to create new types of
615 contexts with different combinations of engraver plug-ins.
617 The next example shows how to build a different type of
618 @code{Voice} context from scratch. It will be similar to
619 @code{Voice}, but only prints centered slash note heads. It can be used
620 to indicate improvisation in jazz pieces,
622 @lilypond[quote,ragged-right]
625 \type "Engraver_group"
626 \consists "Note_heads_engraver"
627 \consists "Text_engraver"
628 \consists Pitch_squash_engraver
629 squashedPosition = #0
630 \override NoteHead #'style = #'slash
631 \override Stem #'transparent = ##t
635 \accepts "ImproVoice"
639 a4 d8 bes8 \new ImproVoice { c4^"ad lib" c
640 c4 c^"undress" c_"while playing :)" c }
646 These settings are defined within a @code{\context} block inside a
647 @code{\layout} block,
657 In the following discussion, the example input shown should go in place
658 of the @dots{} in the previous fragment.
660 First it is necessary to define a name for the new context:
666 Since it is similar to the @code{Voice}, we want commands that work
667 on (existing) @code{Voice}s to remain working. This is achieved by
668 giving the new context an alias @code{Voice},
674 The context will print notes and instructive texts, so we need to add
675 the engravers which provide this functionality,
678 \consists Note_heads_engraver
679 \consists Text_engraver
682 but we only need this on the center line,
685 \consists Pitch_squash_engraver
686 squashedPosition = #0
689 The @rinternals{Pitch_squash_engraver} modifies note heads (created
690 by @rinternals{Note_heads_engraver}) and sets their vertical
691 position to the value of @code{squashedPosition}, in this case@tie{}@code{0},
694 The notes look like a slash, and have no stem,
697 \override NoteHead #'style = #'slash
698 \override Stem #'transparent = ##t
701 All these plug-ins have to cooperate, and this is achieved with a
702 special plug-in, which must be marked with the keyword @code{\type}.
703 This should always be @code{Engraver_group}.
706 \type "Engraver_group"
714 \type "Engraver_group"
715 \consists "Note_heads_engraver"
716 \consists "Text_engraver"
717 \consists Pitch_squash_engraver
718 squashedPosition = #0
719 \override NoteHead #'style = #'slash
720 \override Stem #'transparent = ##t
726 Contexts form hierarchies. We want to hang the @code{ImproVoice}
727 under @code{Staff}, just like normal @code{Voice}s. Therefore, we
728 modify the @code{Staff} definition with the @code{\accepts}
739 The opposite of @code{\accepts} is @code{\denies},
740 which is sometimes needed when reusing existing context definitions.
742 Putting both into a @code{\layout} block, like
752 \accepts "ImproVoice"
757 Then the output at the start of this subsection can be entered as
765 c c_"while playing :)"
772 @node Aligning contexts
773 @subsection Aligning contexts
775 New contexts may be aligned above or below existing contexts. This
776 could be useful in setting up a vocal staff (@rlearning{Vocal ensembles}) and
779 @c TODO Better example needed. Ref LM, and expand on it.
782 @findex alignAboveContext
783 @findex alignBelowContext
785 @lilypond[quote,ragged-right]
788 \relative c' \new Staff = "main" {
791 \new Staff \with {alignAboveContext=main} \ossia
799 @node Explaining the Internals Reference
800 @section Explaining the Internals Reference
804 * Navigating the program reference::
805 * Layout interfaces::
806 * Determining the grob property::
807 * Naming conventions::
810 @node Navigating the program reference
811 @subsection Navigating the program reference
813 @c TODO remove this (it's in the LM)
814 @c Replace with more factual directions
816 Suppose we want to move the fingering indication in the fragment
819 @lilypond[quote,fragment,relative=2,verbatim]
825 If you visit the documentation on fingering instructions (in
826 @ref{Fingering instructions}), you will notice:
831 Internals Reference: @rinternals{Fingering}.
836 @c outdated info; probably will delete.
838 This fragment points to two parts of the program reference: a page
839 on @code{FingeringEvent} and one on @code{Fingering}.
841 The page on @code{FingeringEvent} describes the properties of the music
842 expression for the input @code{-2}. The page contains many links
843 forward. For example, it says
846 Accepted by: @rinternals{Fingering_engraver},
850 That link brings us to the documentation for the Engraver, the
854 This engraver creates the following layout objects: @rinternals{Fingering}.
857 In other words, once the @code{FingeringEvent}s are interpreted, the
858 @code{Fingering_engraver} plug-in will process them.
862 @c I can't figure out what this is supposed to mean. -gp
864 The @code{Fingering_engraver} is also listed to create
865 @rinternals{Fingering} objects,
867 @c old info? it doesn't make any sense to me with our current docs.
869 second bit of information listed under @b{See also} in the Notation
874 The programmer's reference is available as an HTML document. It is
875 highly recommended that you read it in HTML form, either online or
876 by downloading the HTML documentation. This section will be much more
877 difficult to understand if you are using the
881 Follow the link to @rinternals{Fingering}. At the top of the
885 Fingering objects are created by: @rinternals{Fingering_engraver} and
886 @rinternals{New_fingering_engraver}.
889 By following related links inside the program reference, we can follow the
890 flow of information within the program:
894 @item @rinternals{Fingering}:
895 @rinternals{Fingering} objects are created by:
896 @rinternals{Fingering_engraver}
898 @item @rinternals{Fingering_engraver}:
899 Music types accepted: @rinternals{fingering-event}
901 @item @rinternals{fingering-event}:
902 Music event type @code{fingering-event} is in Music expressions named
903 @rinternals{FingeringEvent}
906 This path goes against the flow of information in the program: it
907 starts from the output, and ends at the input event. You could
908 also start at an input event, and read with the flow of
909 information, eventually ending up at the output object(s).
911 The program reference can also be browsed like a normal document. It
914 @rinternals{Music definitions},
917 @code{Music definitions}
919 on @rinternals{Translation}, and the @rinternals{Backend}. Every
920 chapter lists all the definitions used and all properties that may be
924 @node Layout interfaces
925 @subsection Layout interfaces
927 @cindex interface, layout
928 @cindex layout interface
931 The HTML page that we found in the previous section describes the
932 layout object called @rinternals{Fingering}. Such an object is a
933 symbol within the score. It has properties that store numbers (like
934 thicknesses and directions), but also pointers to related objects. A
935 layout object is also called a @emph{Grob}, which is short for Graphical
936 Object. For more details about Grobs, see @rinternals{grob-interface}.
938 The page for @code{Fingering} lists the definitions for the
939 @code{Fingering} object. For example, the page says
942 @code{padding} (dimension, in staff space):
948 which means that the number will be kept at a distance of at least 0.5
952 Each layout object may have several functions as a notational or
953 typographical element. For example, the Fingering object
954 has the following aspects
958 Its size is independent of the horizontal spacing, unlike slurs or beams.
961 It is a piece of text. Granted, it is usually a very short text.
964 That piece of text is typeset with a font, unlike slurs or beams.
967 Horizontally, the center of the symbol should be aligned to the
968 center of the note head.
971 Vertically, the symbol is placed next to the note and the staff.
974 The vertical position is also coordinated with other superscript
975 and subscript symbols.
978 Each of these aspects is captured in so-called @emph{interface}s,
979 which are listed on the @rinternals{Fingering} page at the bottom
982 This object supports the following interfaces:
983 @rinternals{item-interface},
984 @rinternals{self-alignment-interface},
985 @rinternals{side-position-interface}, @rinternals{text-interface},
986 @rinternals{text-script-interface}, @rinternals{font-interface},
987 @rinternals{finger-interface}, and @rinternals{grob-interface}.
990 Clicking any of the links will take you to the page of the respective
991 object interface. Each interface has a number of properties. Some of
992 them are not user-serviceable (@q{Internal properties}), but others
995 We have been talking of @emph{the} @code{Fingering} object, but actually it
996 does not amount to much. The initialization file (see
997 @rlearning{Other sources of information})
998 @file{scm/@/define@/-grobs@/.scm} shows the soul of the @q{object},
1003 (avoid-slur . around)
1004 (slur-padding . 0.2)
1005 (staff-padding . 0.5)
1006 (self-alignment-X . 0)
1007 (self-alignment-Y . 0)
1008 (script-priority . 100)
1009 (stencil . ,ly:text-interface::print)
1010 (direction . ,ly:script-interface::calc-direction)
1011 (font-encoding . fetaNumber)
1012 (font-size . -5) ; don't overlap when next to heads.
1013 (meta . ((class . Item)
1014 (interfaces . (finger-interface
1016 text-script-interface
1018 side-position-interface
1019 self-alignment-interface
1020 item-interface))))))
1024 As you can see, the @code{Fingering} object is nothing more than a
1025 bunch of variable settings, and the webpage in the Internals Reference
1026 is directly generated from this definition.
1029 @node Determining the grob property
1030 @subsection Determining the grob property
1032 @c TODO remove this (it's in the LM)
1033 @c Replace with more factual directions
1035 Recall that we wanted to change the position of the @b{2} in
1037 @lilypond[quote,fragment,relative=2,verbatim]
1043 Since the @b{2} is vertically positioned next to its note, we have to
1044 meddle with the interface associated with this positioning. This is
1045 done using @code{side-position-interface}. The page for this interface
1049 @code{side-position-interface}
1051 Position a victim object (this one) next to other objects (the
1052 support). The property @code{direction} signifies where to put the
1053 victim object relative to the support (left or right, up or down?)
1058 Below this description, the variable @code{padding} is described as
1063 (dimension, in staff space)
1065 Add this much extra space between objects that are next to each other.
1069 By increasing the value of @code{padding}, we can move the
1070 fingering away from the note head. The following command inserts
1071 3 staff spaces of white
1072 between the note and the fingering:
1074 \once \override Voice.Fingering #'padding = #3
1077 Inserting this command before the Fingering object is created,
1078 i.e., before @code{c2}, yields the following result:
1080 @lilypond[quote,relative=2,fragment,verbatim]
1081 \once \override Voice.Fingering #'padding = #3
1088 In this case, the context for this tweak is @code{Voice}. This
1089 fact can also be deduced from the program reference, for the page for
1090 the @rinternals{Fingering_engraver} plug-in says
1093 Fingering_engraver is part of contexts: @dots{} @rinternals{Voice}
1097 @node Naming conventions
1098 @subsection Naming conventions
1100 Another thing that is needed, is an overview of the various naming
1103 scheme functions: lowercase-with-hyphens (incl. one-word
1105 scheme functions: ly:plus-scheme-style
1106 music events, music classes and music properties:
1108 Grob interfaces: scheme-style
1109 backend properties: scheme-style (but X and Y!)
1110 contexts (and MusicExpressions and grobs): Capitalized or
1112 context properties: lowercaseFollowedByCamelCase
1114 Capitalized_followed_by_lowercase_and_with_underscores
1116 Which of these are conventions and which are rules?
1117 Which are rules of the underlying language, and which are
1121 @node Modifying properties
1122 @section Modifying properties
1124 @c TODO change the menu and subsection node names to use
1125 @c backslash once the new macro to handle the refs
1126 @c is available. Need to find and change all refs at
1127 @c the same time. -td
1130 * Overview of modifying properties::
1132 * The override command::
1133 * The tweak command::
1134 * set versus override::
1138 @node Overview of modifying properties
1139 @subsection Overview of modifying properties
1141 Each context is responsible for creating certain types of graphical
1142 objects. The settings used for printing these objects are also stored by
1143 context. By changing these settings, the appearance of objects can be
1146 The syntax for this is
1149 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1152 Here @var{name} is the name of a graphical object, like
1153 @code{Stem} or @code{NoteHead}, and @var{property} is an internal
1154 variable of the formatting system (@q{grob property} or @q{layout
1155 property}). The latter is a symbol, so it must be quoted. The
1156 subsection @ref{Modifying properties}, explains what to fill in
1157 for @var{name}, @var{property}, and @var{value}. Here we only
1158 discuss the functionality of this command.
1163 \override Staff.Stem #'thickness = #4.0
1167 makes stems thicker (the default is 1.3, with staff line thickness as a
1168 unit). Since the command specifies @code{Staff} as context, it only
1169 applies to the current staff. Other staves will keep their normal
1170 appearance. Here we see the command in action:
1172 @lilypond[quote,verbatim,relative=2,fragment]
1174 \override Staff.Stem #'thickness = #4.0
1180 The @code{\override} command changes the definition of the @code{Stem}
1181 within the current @code{Staff}. After the command is interpreted
1182 all stems are thickened.
1184 Analogous to @code{\set}, the @var{context} argument may be left out,
1185 causing the default context @code{Voice} to be used. Adding
1186 @code{\once} applies the change during one timestep only.
1188 @lilypond[quote,fragment,verbatim,relative=2]
1190 \once \override Stem #'thickness = #4.0
1195 The @code{\override} must be done before the object is
1196 started. Therefore, when altering @emph{Spanner} objects such as slurs
1197 or beams, the @code{\override} command must be executed at the moment
1198 when the object is created. In this example,
1200 @lilypond[quote,fragment,verbatim,relative=2]
1201 \override Slur #'thickness = #3.0
1203 \override Beam #'thickness = #0.6
1208 the slur is fatter but the beam is not. This is because the command for
1209 @code{Beam} comes after the Beam is started, so it has no effect.
1211 Analogous to @code{\unset}, the @code{\revert} command for a context
1212 undoes an @code{\override} command; like with @code{\unset}, it only
1213 affects settings that were made in the same context. In other words, the
1214 @code{\revert} in the next example does not do anything.
1217 \override Voice.Stem #'thickness = #4.0
1218 \revert Staff.Stem #'thickness
1221 Some tweakable options are called @q{subproperties} and reside inside
1222 properties. To tweak those, use commands of the form
1224 @c leave this as a long long
1226 \override @var{context}.@var{name} #'@var{property} #'@var{subproperty} = #@var{value}
1233 \override Stem #'details #'beamed-lengths = #'(4 4 3)
1239 Internals: @rinternals{OverrideProperty}, @rinternals{RevertProperty},
1240 @rinternals{PropertySet}, @rinternals{Backend}, and
1241 @rinternals{All layout objects}.
1246 The back-end is not very strict in type-checking object properties.
1247 Cyclic references in Scheme values for properties can cause hangs
1248 or crashes, or both.
1252 @node The set command
1253 @subsection The @code{\set} command
1257 @cindex changing properties
1259 Each context can have different @emph{properties}, variables contained
1260 in that context. They can be changed during the interpretation step.
1261 This is achieved by inserting the @code{\set} command in the music,
1264 \set @var{context}.@var{prop} = #@var{value}
1268 @lilypond[quote,verbatim,relative=2,fragment]
1270 \set Score.skipBars = ##t
1274 This command skips measures that have no notes. The result is that
1275 multi-rests are condensed. The value assigned is a Scheme object. In
1276 this case, it is @code{#t}, the boolean True value.
1278 If the @var{context} argument is left out, then the current bottom-most
1279 context (typically @code{ChordNames}, @code{Voice}, or
1280 @code{Lyrics}) is used. In this example,
1282 @lilypond[quote,verbatim,relative=2,fragment]
1284 \set autoBeaming = ##f
1289 the @var{context} argument to @code{\set} is left out, so automatic
1290 beaming is switched off in the current @rinternals{Voice}. Note that
1291 the bottom-most context does not always contain the property that you
1292 wish to change -- for example, attempting to set the @code{skipBars}
1293 property (of the bottom-most context, in this case @code{Voice}) will
1296 @lilypond[quote,verbatim,relative=2,fragment]
1302 Contexts are hierarchical, so if a bigger context was specified, for
1303 example @code{Staff}, then the change would also apply to all
1304 @code{Voice}s in the current stave. The change is applied
1305 @q{on-the-fly}, during the music, so that the setting only affects the
1306 second group of eighth notes.
1310 There is also an @code{\unset} command,
1312 \unset @var{context}.@var{prop}
1316 which removes the definition of @var{prop}. This command removes
1317 the definition only if it is set in @var{context}, so
1320 \set Staff.autoBeaming = ##f
1324 introduces a property setting at @code{Staff} level. The setting also
1325 applies to the current @code{Voice}. However,
1328 \unset Voice.autoBeaming
1332 does not have any effect. To cancel this setting, the @code{\unset}
1333 must be specified on the same level as the original @code{\set}. In
1334 other words, undoing the effect of @code{Staff.autoBeaming = ##f}
1337 \unset Staff.autoBeaming
1340 Like @code{\set}, the @var{context} argument does not have to be
1341 specified for a bottom context, so the two statements
1344 \set Voice.autoBeaming = ##t
1345 \set autoBeaming = ##t
1353 Settings that should only apply to a single time-step can be entered
1354 with @code{\once}, for example in
1356 @lilypond[quote,verbatim,relative=2,fragment]
1358 \once \set fontSize = #4.7
1363 the property @code{fontSize} is unset automatically after the second
1366 A full description of all available context properties is in the
1367 program reference, see
1369 @rinternals{Tunable context properties}.
1372 Translation @expansion{} Tunable context properties.
1377 @node The override command
1378 @subsection The @code{\override} command
1380 Commands which change output generally look like
1383 \override Voice.Stem #'thickness = #3.0
1387 To construct this tweak we must determine these bits of information:
1390 @item the context: here @code{Voice}.
1391 @item the layout object: here @code{Stem}.
1392 @item the layout property: here @code{thickness}.
1393 @item a sensible value: here @code{3.0}.
1396 Some tweakable options are called @q{subproperties} and reside inside
1397 properties. To tweak those, use commands in the form
1400 \override Stem #'details #'beamed-lengths = #'(4 4 3)
1403 @cindex internal documentation
1404 @cindex finding graphical objects
1405 @cindex graphical object descriptions
1408 @cindex internal documentation
1410 For many properties, regardless of the data type of the property, setting the
1411 property to false ( @code{##f} ) will result in turning it off, causing
1412 LilyPond to ignore that property entirely. This is particularly useful for
1413 turning off grob properties which may otherwise be causing problems.
1415 We demonstrate how to glean this information from the notation manual
1416 and the program reference.
1419 @node The tweak command
1420 @subsection The @code{\tweak} command
1425 In some cases, it is possible to take a short-cut for tuning
1426 graphical objects. For objects that are created directly from
1427 an item in the input file, you can use the @code{\tweak} command.
1430 @lilypond[relative=2,verbatim]
1435 \tweak #'duration-log #1
1438 -\tweak #'padding #8
1442 @cindex chord, modifying one note in
1444 But the main use of the @code{\tweak} command is to modify just
1445 one of a number of notation elements which start at the same musical
1446 moment, like the notes of a chord, or tuplet brackets which start
1449 For an introduction to the syntax and uses of the tweak command
1450 see @rlearning{Tweaking methods}.
1452 The @code{\tweak} command sets a property in the following object
1453 directly, without requiring the grob name or context to be
1454 specified. For this to work, it is necessary for the @code{\tweak}
1455 command to remain immediately adjacent to the object to which it is
1456 to apply after the input file has been converted to a music stream.
1457 This is often not the case, as many additional elements are inserted
1458 into the music stream implicitly. For example, when a note which is
1459 not part of a chord is processed, Lilypond implicitly inserts a
1460 @code{ChordEvent} event before the note, so separating the tweak
1461 from the note. However, if chord symbols are placed round the
1462 tweak and the note, the @code{\tweak} command comes after the
1463 @code{ChordEvent} in the music stream, so remaining adjacent to the
1464 note, and able to modify it.
1468 @lilypond[relative=2,verbatim,quote]
1469 <\tweak #'color #red c>4
1475 @lilypond[relative=2,verbatim,quote]
1476 \tweak #'color #red c4
1479 When several similar items are placed at the same musical moment,
1480 the @code{\override} command cannot be used to modify just one of
1481 them -- this is where the @code{\tweak} command must be used.
1482 Items which may appear more than once at the same musical moment
1483 include the following:
1485 @c TODO expand to include any further uses of \tweak
1487 @item note heads of notes inside a chord
1488 @item articulation signs on a single note
1489 @item ties between notes in a chord
1490 @item tuplet brackets starting at the same time
1493 @c TODO add examples of these
1496 and @code{\tweak} may be used to modify any single occurrence of
1499 Notably the @code{\tweak} command cannot be used to modify stems,
1500 beams or accidentals, since these are generated later by note heads,
1501 rather than by music elements in the input stream. Nor can a
1502 @code{\tweak} command be used to modify clefs or time signatures,
1503 since these become separated from any preceding @code{\tweak}
1504 command in the input stream by the automatic insertion of extra
1505 elements required to specify the context.
1507 But the @code{\tweak} command can be used as an alternative to
1508 the @code{\override} command to modify those notational elements
1509 that do not cause any additional implicit elements to be added
1510 before them in the music stream. For example, slurs may be
1511 modified in this way:
1513 @lilypond[verbatim,quote,relative=1]
1514 c-\tweak #'thickness #5 ( d e f)
1517 Also several @code{\tweak} commands may be placed before a
1518 notational element -- all affect it:
1520 @lilypond[verbatim,quote,relative=1]
1522 -\tweak #'style #'dashed-line
1523 -\tweak #'dash-fraction #0.2
1524 -\tweak #'thickness #3
1525 -\tweak #'color #red
1530 The music stream which is generated from a section of an input file,
1531 including any automatically inserted elements, may be examined,
1532 see @ref{Displaying music expressions}. This may be helpful in
1533 determining what may be modified by a @code{\tweak} command.
1538 @rlearning{Tweaking methods}.
1541 @ref{Displaying music expressions}.
1545 @cindex tweaks in a variable
1546 The @code{\tweak} command cannot be used inside a variable.
1548 @cindex tweaks in lyrics
1549 The @code{\tweak} commands cannot be used in @code{\lyricmode}.
1551 @cindex tweaking control points
1552 @cindex control points, tweaking
1554 The @code{\tweak} command cannot be used to modify the control
1555 points of just one of several ties in a chord, other than the first
1556 one encountered in the input file.
1558 @node set versus override
1559 @subsection @code{\set} vs. @code{\override}
1561 We have seen two methods of changing properties: @code{\set} and
1562 @code{\override}. There are actually two different kinds of
1565 Contexts can have properties, which are usually named in
1566 @code{studlyCaps}. They mostly control the translation from
1567 music to notation, eg. @code{localKeySignature} (for determining
1568 whether to print accidentals), @code{measurePosition} (for
1569 determining when to print a bar line). Context properties can
1570 change value over time while interpreting a piece of music;
1571 @code{measurePosition} is an obvious example of
1572 this. Context properties are modified with @code{\set}.
1574 There is a special type of context property: the element
1575 description. These properties are named in @code{StudlyCaps}
1576 (starting with capital letters). They contain the
1577 @q{default settings} for said graphical object as an
1578 association list. See @file{scm/@/define@/-grobs@/.scm}
1579 to see what kind of settings there are. Element descriptions
1580 may be modified with @code{\override}.
1582 @code{\override} is actually a shorthand;
1585 \override @var{context}.@var{name} #'@var{property} = #@var{value}
1589 is more or less equivalent to
1591 @c leave this long line -gp
1593 \set @var{context}.@var{name} #'@var{property} = #(cons (cons '@var{property} @var{value}) <previous value of @var{context})
1596 The value of @code{context} (the alist) is used to initialize
1597 the properties of individual grobs. Grobs also have
1598 properties, named in Scheme style, with
1599 @code{dashed-words}. The values of grob properties change
1600 during the formatting process: formatting basically amounts
1601 to computing properties using callback functions.
1603 @code{fontSize} is a special property: it is equivalent to
1604 entering @code{\override ... #'font-size} for all pertinent
1605 objects. Since this is a common change, the special
1606 property (modified with @code{\set}) was created.
1609 @node Useful concepts and properties
1610 @section Useful concepts and properties
1615 * Direction and placement::
1616 * Distances and measurements::
1618 * Visibility of objects::
1620 * Rotating objects::
1624 @subsection Input modes
1626 The way in which the notation contained within an input file is
1627 interpreted is determined by the current input mode.
1631 This is activated with the @code{\chordmode} command, and causes
1632 input to be interpreted with the syntax of chord notation, see
1633 @ref{Chord notation}. Chords are rendered as notes on a staff.
1635 Chord mode is also activated with the @code{\chords} command.
1636 This also creates a new @code{ChordNames} context and
1637 causes the following input to be interpreted with the syntax of
1638 chord notation and rendered as chord names in the @code{ChordNames}
1639 context, see @ref{Printing chord names}.
1643 This is activated with the @code{\drummode} command, and causes
1644 input to be interpreted with the syntax of drum notation, see
1645 @ref{Basic percussion notation}.
1647 Drum mode is also activated with the @code{\drums} command.
1648 This also creates a new @code{DrumStaff} context and causes the
1649 following input to be interpreted with the syntax of drum notation
1650 and rendered as drum symbols on a drum staff, see @ref{Basic
1651 percussion notation}.
1653 @strong{Figure mode}
1655 This is activated with the @code{\figuremode} command, and causes
1656 input to be interpreted with the syntax of figured bass, see
1657 @ref{Entering figured bass}.
1659 Figure mode is also activated with the @code{\figures} command.
1660 This also creates a new @code{FiguredBass} context and causes the
1661 following input to be interpreted with the figured bass syntax
1662 and rendered as figured bass symbols in the @code{FiguredBass}
1663 context, see @ref{Introduction to figured bass}.
1665 @strong{Fret and tab modes}
1667 There are no special input modes for entering fret and tab symbols.
1669 To create tab diagrams, enter notes or chords in note mode and
1670 render them in a @code{TabStaff} context, see
1671 @ref{Default tablatures}.
1673 To create fret diagrams above a staff, you have two choices.
1674 You can either use the @code{FretBoards} context (see
1675 @ref{Automatic fret diagrams} or you can enter them as a markup
1676 above the notes using the @code{\fret-diagram} command (see
1677 @ref{Fret diagram markups}).
1679 @strong{Lyrics mode}
1681 This is activated with the @code{\lyricmode} command, and causes
1682 input to be interpreted as lyric syllables with optional durations
1683 and associated lyric modifiers, see @ref{Vocal music}.
1685 Lyric mode is also activated with the @code{\addlyrics} command.
1686 This also creates a new @code{Lyrics} context and an implicit
1687 @code{\lyricsto} command which associates the following lyrics
1688 with the preceding music.
1690 @strong{Markup mode}
1692 This is activated with the @code{\markup} command, and causes
1693 input to be interpreted with the syntax of markup, see
1694 @ref{Text markup commands}.
1696 @c silly work-around for texinfo broken-ness
1697 @c (@strong{Note...} causes a spurious cross-reference in Info)
1700 This is the default mode or it may be activated with the
1701 @code{\notemode} command. Input is interpreted as pitches,
1702 durations, markup, etc and typeset as musical notation on a staff.
1704 It is not normally necessary to specify note mode explicitly, but
1705 it may be useful to do so in certain situations, for example if you
1706 are in lyric mode, chord mode or any other mode and want to insert
1707 something that only can be done with note mode syntax.
1709 For example, to indicate dynamic markings for the verses of a
1710 choral pieces it is necessary to enter note mode to interpret
1713 @lilypond[verbatim,relative=2,quote]
1716 \notemode{\set stanza = \markup{ \dynamic f 1. } }
1720 \notemode{\set stanza = \markup{ \dynamic p 2. } }
1727 @node Direction and placement
1728 @subsection Direction and placement
1730 In typesetting music the direction and placement of many items is
1731 a matter of choice. For example, the stems of notes can
1732 be directed up or down; lyrics, dynamics, and other expressive
1733 marks may be placed above or below the staff; text may be aligned
1734 left, right or center; etc. Most of these choices may be left to
1735 be determined automatically by LilyPond, but in some cases it may
1736 be desirable to force a particular direction or placement.
1738 @strong{Default actions}
1740 By default some directions are always up or always down (e.g.
1741 dynamics or fermata), while other things can alternate between
1742 up or down based on the stem direction (like slurs or accents).
1744 @c TODO Add table showing these
1746 @strong{Context layout}
1748 Contexts are positioned in a system from top to bottom in the
1749 order in which they are encountered. Note, however, that a
1750 context will be created implicitly if a command is encountered
1751 when there is no suitable context available to contain it.
1753 @c TODO Add example ?
1755 The default order in which contexts are laid out can be changed,
1756 see @ref{Aligning contexts}
1758 @strong{Articulation direction indicators}
1760 When adding articulations to notes the direction indicator,
1761 @code{^} (meaning @qq{up}), @code{_} (meaning @qq{down}) or
1762 @code{-} (meaning @qq{use default direction}), can usually be
1763 omitted, in which case @code{-} is assumed. But a direction
1764 indicator is @strong{always} required before
1767 @item @code{\tweak} commands
1768 @item @code{\markup} commands
1769 @item @code{\tag} commands
1770 @item string markups, e.g. -"string"
1771 @item fingering instructions, e.g. @code{-1}
1772 @item articulation shortcuts, e.g. @code{-.}, @code{->}, @code{--}
1775 @strong{The direction property}
1777 The position or direction of many layout objects is controlled
1778 by the @code{direction} property.
1780 The value of the @code{direction} property may be
1781 set to @code{1}, meaning @qq{up} or @qq{above}, or to @code{-1},
1782 meaning @qq{down} or @qq{below}. The symbols @code{UP} and
1783 @code{DOWN} may be used instead of @code{1} and @code{-1}
1784 respectively. The default direction may be specified by setting
1785 @code{direction} to @code{0} or @code{CENTER}. Alternatively,
1786 in many cases predefined commands
1787 exist to specify the direction. These are all of the form
1790 @code{\xxxUp}, @code{xxxDown}, @code{xxxNeutral}
1793 where @code{xxxNeutral} means @qq{use the default direction}.
1794 See @rlearning{Within-staff objects}.
1796 In a few cases, arpeggio being the only common example, the value
1797 of the @code{direction} property specifies whether the object
1798 is to be placed to the right or left of the parent object. In
1799 this case @code{-1} or @code{LEFT} means @qq{to the left} and
1800 @code{1} or @code{RIGHT} means @qq{to the right}. @code{0}
1801 or @code{CENTER} means @qq{use the default} direction, as before.
1804 These all have side-axis set to #X
1805 AmbitusAccidental - direction has no effect
1807 StanzaNumber - not tried
1808 TrillPitchAccidental - not tried
1809 TrillPitchGroup - not tried
1814 @node Distances and measurements
1815 @subsection Distances and measurements
1819 @c FIXME DISCUSS after working on other sections.
1821 @c TODO: staff spaces. Maybe move into tweaks?
1825 @subsection Spanners
1827 Many objects of musical notation extend over several notes or even
1828 several bars. Examples are slurs, beams, tuplet brackets, volta
1829 repeat brackets, crescendi, trills, and glissandi. Such objects
1830 are collectively called @qq{spanners}, and have special properties to control
1831 their appearance and behaviour. Some of these properties are common
1832 to all spanners; others are restricted to a sub-set of the spanners.
1834 All spanners support the @code{spanner-interface}. A few, esentially
1835 those that draw a straight line between the two objects, support in
1836 addition the @code{line-spanner-interface}.
1838 @unnumberedsubsubsec Using the @code{spanner-interface}
1840 This interface provides two properties that apply to several spanners.
1842 @strong{@i{The @code{minimum-length} property}}
1844 The minimum length of the spanner is specified by the
1845 @code{minimum-length} property. Increasing this usually has the
1846 necessary effect of increasing the spacing of the notes between the
1847 two end points. However, this override has no effect on
1848 many spanners, as their length is determined by other considerations.
1849 A few examples where it is effective are shown below.
1859 Works as long as callback is made:
1863 Works not at all for:
1872 @lilypond[verbatim,quote,relative=2]
1875 % increase the length of the tie
1876 -\tweak #'minimum-length #5
1880 @lilypond[verbatim,quote,relative=2]
1882 \compressFullBarRests
1884 % increase the length of the rest bar
1885 \once \override MultiMeasureRest #'minimum-length = #20
1890 @lilypond[verbatim,quote,relative=2]
1892 % increase the length of the hairpin
1893 \override Hairpin #'minimum-length = #20
1897 This override can also be used to increase the length of slurs and
1900 @lilypond[verbatim,quote,relative=2]
1903 -\tweak #'minimum-length #5
1908 -\tweak #'minimum-length #5
1912 For some layout objects, the @code{minimum-length} property becomes
1913 effective only if the @code{set-spacing-rods} procedure is called
1914 explicitly. To do this, the @code{springs-and-rods} property should
1915 be set to @code{ly:spanner::set-spacing-rods}. For example,
1916 the minimum length of a glissando has no effect unless the
1917 @code{springs-and-rods} property is set:
1919 @lilypond[verbatim,quote,relative=1]
1923 % not effective alone
1924 \once \override Glissando #'minimum-length = #20
1927 % effective only when both overrides are present
1928 \once \override Glissando #'minimum-length = #20
1929 \once \override Glissando #'springs-and-rods = #ly:spanner::set-spacing-rods
1933 The same is true of the @code{Beam} object:
1935 @lilypond[verbatim,quote,relative=1]
1936 % not effective alone
1937 \once \override Beam #'minimum-length = #20
1940 % effective only when both overrides are present
1941 \once \override Beam #'minimum-length = #20
1942 \once \override Beam #'springs-and-rods = #ly:spanner::set-spacing-rods
1946 @strong{@i{The @code{to-barline} property}}
1948 The second useful property of the @code{spanner-interface} is
1949 @code{to-barline}. By default this is true, causing hairpins and
1950 other spanners which are terminated on the first note of a measure to
1951 end instead on the immediately preceding bar line. If set to false,
1952 the spanner will extend beyond the bar line and end on the note
1955 @lilypond[verbatim,quote,relative=2]
1956 a \< a a a a \! a a a \break
1957 \override Hairpin #'to-barline = ##f
1958 a \< a a a a \! a a a
1961 This property is not effective for all spanners. For example,
1962 seting it to @code{#t} has no effect on slurs or phrasing slurs
1963 or on other spanners for which terminating on the bar line would
1966 @unnumberedsubsubsec Using the @code{line-spanner-interface}
1968 Objects which support the @code{line-spanner-interface} include
1971 @item @code{DynamicTextSpanner}
1972 @item @code{Glissando}
1973 @item @code{TextSpanner}
1974 @item @code{TrillSpanner}
1975 @item @code{VoiceFollower}
1978 The routine responsible for drawing the stencils for these spanners is
1979 @code{ly:line-interface::print}. This routine determines the
1980 exact location of the two end points and draws a line
1981 between them, in the style requested. The locations of the two
1982 end points of the spanner are computed on-the-fly, but it is
1983 possible to override their Y-coordinates. The
1984 properties which need to be specified are nested
1985 two levels down within the property hierarchy, but the syntax of
1986 the @code{\override} command is quite simple:
1988 @lilypond[relative=2,quote,verbatim]
1990 \once \override Glissando #'bound-details #'left #'Y = #3
1991 \once \override Glissando #'bound-details #'right #'Y = #-2
1995 The units for the @code{Y} property are @code{staff-space}s,
1996 with the center line of the staff being the zero point.
1997 For the glissando, this is the value for @code{Y} at the
1998 X-coordinate corresponding to the center point of each note head,
1999 if the line is imagined to be extended to there.
2001 If @code{Y} is not set, the value is computed from the vertical
2002 position of the corresponding attachment point of the spanner.
2004 In case of a line break, the values for the end points are
2005 specified by the @code{left-broken} and @code{right-broken}
2006 sub-lists of @code{bound-details}. For example:
2008 @lilypond[relative=2,ragged-right,verbatim,fragment]
2009 \override Glissando #'breakable = ##t
2010 \override Glissando #'bound-details #'right-broken #'Y = #-3
2011 c1 \glissando \break
2016 A number of further properties of the @code{left} and
2017 @code{right} sub-lists of the @code{bound-details} property
2018 may be modified in the same way as @code{Y}:
2022 This sets the Y-coordinate of the end point, in @code{staff-space}s
2023 offset from the staff center line. By default, it is the center of
2024 the bound object, so a glissando points to the vertical center of
2027 For horizontal spanners, such as text spanners and trill spanners,
2028 it is hardcoded to 0.
2031 This determines where the line starts and ends in the X-direction,
2032 relative to the bound object. So, a value of @code{-1} (or
2033 @code{LEFT}) makes the line start/end at the left side of the note
2034 head it is attached to.
2037 This is the absolute X-coordinate of the end point. It is usually
2038 computed on the fly, and overriding it has little useful effect.
2041 Line spanners may have symbols at the beginning or end, which is
2042 contained in this sub-property. This is for internal use; it is
2043 recommended that @code{text} be used instead.
2046 This is a markup that is evaluated to yield the stencil. It is used
2047 to put @i{cresc.}, @i{tr} and other text on horizontal spanners.
2049 @lilypond[quote,ragged-right,fragment,relative=2,verbatim]
2050 \override TextSpanner #'bound-details #'left #'text
2051 = \markup { \small \bold Slower }
2052 c2\startTextSpan b c a\stopTextSpan
2055 @item stencil-align-dir-y
2056 @item stencil-offset
2057 Without setting one of these, the stencil is simply put at the
2058 end-point, centered on the line, as defined by the @code{X} and
2059 @code{Y} sub-properties. Setting either @code{stencil-align-dir-y}
2060 or @code{stencil-offset} will move the symbol at the edge vertically
2061 relative to the end point of the line:
2063 @lilypond[relative=1,fragment,verbatim]
2064 \override TextSpanner #'bound-details
2065 #'left #'stencil-align-dir-y = #-2
2066 \override TextSpanner #'bound-details
2067 #'right #'stencil-align-dir-y = #UP
2069 \override TextSpanner #'bound-details
2070 #'left #'text = #"ggg"
2071 \override TextSpanner #'bound-details
2072 #'right #'text = #"hhh"
2073 c4^\startTextSpan c c c \stopTextSpan
2076 Note that negative values move the text @emph{up}, contrary to the
2077 effect that might be expected, as a value of @code{-1} or
2078 @code{DOWN} means align the @emph{bottom} edge of the text with
2079 the spanner line. A value of @code{1} or @code{UP} aligns
2080 the top edge of the text with the spanner line.
2083 Setting this sub-property to @code{#t} produces an arrowhead at the
2087 This sub-property controls the space between the specified
2088 end point of the line and the actual end. Without padding, a
2089 glissando would start and end in the center of each note head.
2093 The music function @code{\endSpanners} terminates the spanner
2094 which starts on the immediately following note prematurely. It
2095 is terminated after exactly one note, or at the following bar line
2096 if @code{to-barline} is true and a bar line occurs before the next
2099 @lilypond[verbatim,quote,ragged-right,relative=2,fragment]
2101 c2 \startTextSpan c2 c2
2106 When using @code{\endSpanners} it is not necessary to close
2107 \startTextSpan with \stopTextSpan, nor is it necessary to close
2108 hairpins with @code{\!}.
2114 Internals Reference: @rinternals{TextSpanner},
2115 @rinternals{Glissando}, @rinternals{VoiceFollower},
2116 @rinternals{TrillSpanner},
2117 @rinternals{line-spanner-interface}.
2120 @node Visibility of objects
2121 @subsection Visibility of objects
2123 @cindex objects, visibility of
2124 @cindex grobs, visibility of
2125 @cindex visibility of objects
2127 There are four main ways in which the visibility of layout objects
2128 can be controlled: their stencil can be removed, they can be made
2129 transparent, they can be colored white, or their
2130 @code{break-visibility} property can be overridden. The first
2131 three apply to all layout objects; the last to just a few -- the
2132 @emph{breakable} objects. The Learning Manual introduces these
2133 four techniques, see @rlearning{Visibility and color of objects}.
2135 There are also a few other techniques which are specific to
2136 certain layout objects. These are covered under Special
2140 * Removing the stencil::
2141 * Making objects transparent::
2142 * Painting objects white::
2143 * Using break-visibility::
2144 * Special considerations::
2148 @node Removing the stencil
2149 @unnumberedsubsubsec Removing the stencil
2151 @cindex stencil, removing
2153 Every layout object has a stencil property. By default this is set
2154 to the specific function which draws that object. If this property
2155 is overridden to @code{#f} no function will be called and the object
2156 will not be drawn. The default action can be recovered with
2159 @lilypond[quote,verbatim,relative=1]
2161 \override Score.BarLine #'stencil = ##f
2163 \revert Score.BarLine #'stencil
2167 @node Making objects transparent
2168 @unnumberedsubsubsec Making objects transparent
2170 @cindex transparent, making objects
2172 Every layout object has a transparent property which by default is
2173 set to @code{#f}. If set to @code{#t} the object still occupies
2174 space but is made invisible.
2176 @lilypond[quote,verbatim,relative=2]
2178 \once \override NoteHead #'transparent = ##t
2182 @node Painting objects white
2183 @unnumberedsubsubsec Painting objects white
2185 @cindex objects, coloring
2186 @cindex coloring objects
2188 @cindex printing order
2189 @cindex overwriting objects
2190 @cindex objects, overwriting
2191 @cindex grobs, overwriting
2193 Every layout object has a color property which by default is set
2194 to @code{black}. If this is overridden to @code{white} the object
2195 will be indistinguishable from the white background. However,
2196 if the object crosses other objects the color of the crossing
2197 points will be determined by the order in which they are drawn,
2198 and this may leave a ghostly image of the white object, as shown
2201 @lilypond[quote,verbatim,relative=2]
2202 \override Staff.Clef #'color = #white
2206 This may be avoided by changing the order of printing the objects.
2207 All layout objects have a @code{layer} property which should be set
2208 to an integer. Objects with the lowest value of @code{layer} are
2209 drawn first, then objects with progressively higher values are drawn,
2210 so objects with higher values overwrite objects with lower values.
2211 By default most objects are assigned a @code{layer} value of
2212 @code{1}, although a few objects, including @code{StaffSymbol} and
2213 @code{BarLine}, are assigned a value of @code{0}. The order of
2214 printing objects with the same value of @code{layer} is indeterminate.
2216 In the example above the white clef, with a default @code{layer}
2217 value of @code{1}, is drawn after the staff lines (default
2218 @code{layer} value @code{0}), so overwriting them. To change this,
2219 the @code{Clef} object must be given in a lower value of
2220 @code{layer}, say @code{-1}, so that it is drawn earlier:
2222 @lilypond[quote,verbatim,relative=2]
2223 \override Staff.Clef #'color = #white
2224 \override Staff.Clef #'layer = #-1
2228 @node Using break-visibility
2229 @unnumberedsubsubsec Using break-visibility
2231 @c TODO Add making other objects breakable
2233 @cindex break-visibility
2235 Most layout objects are printed only once, but some like
2236 bar lines, clefs, time signatures and key signatures, may need
2237 to be printed twice when a line break occurs -- once at the end
2238 of the line and again at the start of the next line. Such
2239 objects are called @emph{breakable}, and have a property, the
2240 @code{break-visibility} property to control their visibility
2241 at the three positions in which they may appear -- at the
2242 start of a line, within a line if they are changed, and at the
2243 end of a line if a change takes place there.
2245 For example, the time signature
2246 by default will be printed at the start of the first line, but
2247 nowhere else unless it changes, when it will be printed at the
2248 point at which the change occurs. If this change occurs at the
2249 end of a line the new time signature will be printed at the start
2250 of the next line and a cautionary time signature will be printed
2251 at the end of the previous line as well.
2253 This behaviour is controlled by the @code{break-visibility}
2254 property, which is explained in
2255 @c Leave this ref on a newline - formats incorrectly otherwise -td
2256 @rlearning{Visibility and color of objects}. This property takes
2257 a vector of three booleans which, in order, determine whether the
2258 object is printed at the end of, within the body of, or at the
2259 beginning of a line. Or to be more precise, before a line break,
2260 where there is no line break, or after a line break.
2262 Alternatively, seven of the eight combinations may be specified
2263 by pre-defined functions, defined in @file{scm/output-lib.scm},
2264 where the last three columns indicate whether the layout objects
2265 will be visible in the positions shown at the head of the columns:
2267 @multitable @columnfractions .40 .15 .1 .1 .1
2268 @c TODO check these more carefully
2269 @headitem Function @tab Vector @tab Before @tab At no @tab After
2270 @headitem form @tab form @tab break @tab break @tab break
2272 @item @code{all-invisible} @tab @code{'#(#f #f #f)} @ @ @tab no @tab no @tab no
2273 @item @code{begin-of-line-visible} @tab @code{'#(#f #f #t)} @tab no @tab no @tab yes
2274 @item @code{end-of-line-visible} @tab @code{'#(#t #f #f)} @tab yes @tab no @tab no
2275 @item @code{all-visible} @tab @code{'#(#t #t #t)} @tab yes @tab yes @tab yes
2276 @c The center-visible function is not defined
2277 @c @item @code{center-visible} @tab @code{'#(#f #t #f)} @tab no @tab yes @tab no
2278 @item @code{begin-of-line-invisible} @tab @code{'#(#t #t #f)} @tab yes @tab yes @tab no
2279 @item @code{end-of-line-invisible} @tab @code{'#(#f #t #t)} @tab no @tab yes @tab yes
2280 @item @code{center-invisible} @tab @code{'#(#t #f #t)} @tab yes @tab no @tab yes
2283 The @code{center-visible} function is not pre-defined.
2285 The default settings of @code{break-visibility} depend on the
2286 layout object. The following table shows all the layout objects
2287 of interest which are affected by @code{break-visibility} and the
2288 default setting of this property:
2290 @multitable @columnfractions .3 .3 .4
2292 @headitem Layout object @tab Usual context @tab Default setting
2294 @c omit Ambitus as it appears not to be affected by break-visibility -td
2295 @c @item @code{Ambitus} @tab as specified @tab @code{begin-of-line-visible}
2296 @item @code{BarLine} @tab @code{Score} @tab calculated
2297 @item @code{BarNumber} @tab @code{Score} @tab @code{begin-of-line-visible}
2298 @c omit the following item until it can be explained -td
2299 @c @item @code{BreakAlignGroup} @tab @code{Score} @tab calculated
2300 @item @code{BreathingSign} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2301 @item @code{Clef} @tab @code{Staff} @tab @code{begin-of-line-visible}
2302 @item @code{Custos} @tab @code{Staff} @tab @code{end-of-line-visible}
2303 @item @code{DoublePercentRepeat} @tab @code{Voice} @tab @code{begin-of-line-invisible}
2304 @c omit KeyCancellation until it can be explained -td
2305 @c @item @code{KeyCancellation} @tab ?? @tab @code{begin-of-line-invisible}
2306 @item @code{KeySignature} @tab @code{Staff} @tab @code{begin-of-line-visible}
2307 @c omit LeftEdge until it can be explained -td
2308 @c @item @code{LeftEdge} @tab @code{Score} @tab @code{center-invisible}
2309 @item @code{OctavateEight} @tab @code{Staff} @tab @code{begin-of-line-visible}
2310 @item @code{RehearsalMark} @tab @code{Score} @tab @code{end-of-line-invisible}
2311 @item @code{TimeSignature} @tab @code{Staff} @tab @code{all-visible}
2315 The example below shows the use of the vector form to control the
2316 visibility of barlines:
2318 @lilypond[quote,verbatim,relative=1,ragged-right]
2321 % Remove bar line at the end of the current line
2322 \once \override Score.BarLine #'break-visibility = #'#(#f #t #t)
2328 Although all three components of the vector used to override
2329 @code{break-visibility} must be present, not all of them are
2330 effective with every layout object, and some combinations may
2331 even give errors. The following limitations apply:
2334 @item Bar lines cannot be printed at start of line.
2335 @item A bar number cannot be printed at the start of the first
2336 line unless it is set to be different from 1.
2337 @item Clef -- see below
2338 @item Double percent repeats are either all printed or all
2339 suppressed. Use begin-of line-invisible to print and
2340 all-invisible to suppress.
2341 @item Key signature -- see below
2342 @item OctavateEight -- see below
2345 @node Special considerations
2346 @unnumberedsubsubsec Special considerations
2348 @strong{@emph{Visibility following explicit changes}}
2350 @cindex key signature, visibility following explicit change
2351 @cindex explicitKeySignatureVisibility
2352 @cindex clef, visibility following explicit change
2353 @cindex explicitClefVisibility
2355 The @code{break-visibility} property controls the visibility of
2356 key signatures and changes of clef only at the start of lines,
2357 i.e. after a break. It has no effect on the visibility of the
2358 key signature or clef following an explicit key change or an
2359 explicit clef change within or at the end of a line. In the
2360 following example the key signature following the explicit change
2361 to B-flat major is still visible, even though @code{all-invisible}
2364 @lilypond[quote,verbatim,relative=1,ragged-right]
2367 % Try to remove all key signatures
2368 \override Staff.KeySignature #'break-visibility = #all-invisible
2376 The visibility of such explicit key signature and clef changes is
2377 controlled by the @code{explicitKeySignatureVisibility} and
2378 @code{explicitClefVisibility} properties. These are the equivalent
2379 of the @code{break-visibility} property and both take a vector of
2380 three booleans or the predefined functions listed above, exactly like
2381 @code{break-visibility}. Both are properties of the Staff context,
2382 not the layout objects themselves, and so they are set using the
2383 @code{\set} command. Both are set by default to @code{all-visible}.
2384 These properties control only the visibility of key signatures and
2385 clefs resulting from explicit changes and do not affect key
2386 signatures and clefs at the beginning of lines;
2387 @code{break-visibility} must still be overridden in the appropriate
2388 object to remove these.
2390 @lilypond[quote,verbatim,relative=1,ragged-right]
2393 \set Staff.explicitKeySignatureVisibility = #all-invisible
2394 \override Staff.KeySignature #'break-visibility = #all-invisible
2401 @strong{@emph{Visibility of cautionary accidentals}}
2403 To remove the cautionary accidentals printed at an explicit key
2404 change, set the Staff context property @code{printKeyCancellation}
2407 @lilypond[quote,verbatim,relative=1,ragged-right]
2410 \set Staff.explicitKeySignatureVisibility = #all-invisible
2411 \set Staff.printKeyCancellation = ##f
2412 \override Staff.KeySignature #'break-visibility = #all-invisible
2419 With these overrides only the accidentals before the notes remain
2420 to indicate the change of key.
2422 @c TODO Add visibility of cautionary accidentals before notes
2424 @strong{@emph{Automatic bars}}
2426 @cindex automaticBars
2427 @cindex bar lines, suppressing
2429 As a special case, the printing of bar lines can also be turned off
2430 by setting the @code{automaticBars} property in the Score context.
2431 If set to @code{#f}, bar lines will not be printed automatically;
2432 they must be explicitly created with a @code{\bar} command. Unlike
2433 the @code{\cadenzaOn} predefined command, measures are still counted.
2434 Bar generation will resume according to that count if this property
2435 is later set to @code{#t}. When set to @code{#f}, line breaks can
2436 occur only at explicit @code{\bar} commands.
2440 @strong{@emph{Octavated clefs}}
2442 @cindex octavated clefs, visibility of
2443 @cindex visibility of octavated clefs
2444 @cindex clefs, visibility of octavation
2446 The small octavation symbol on octavated clefs is produced by the
2447 @code{OctavateEight} layout object. Its visibility is controlled
2448 independently from that of the @code{Clef} object, so it is
2449 necessary to apply any required @code{break-visibility} overrides
2450 to both the @code{Clef} and the @code{OctavateEight} layout objects
2451 to fully suppress such clef symbols at the start of each line.
2453 For explicit clef changes, the @code{explicitClefVisibility}
2454 property controls both the clef symbol and any octavation symbol
2460 @rlearning{Visibility and color of objects}
2464 @subsection Line styles
2466 Some performance indications, e.g., @i{rallentando} and
2467 @i{accelerando} and @i{trills} are written as text and are
2468 extended over many measures with lines, sometimes dotted or wavy.
2470 These all use the same routines as the glissando for drawing the
2471 texts and the lines, and tuning their behavior is therefore also
2472 done in the same way. It is done with a spanner, and the routine
2473 responsible for drawing the spanners is
2474 @code{ly:line-interface::print}. This routine determines the
2475 exact location of the two @i{span points} and draws a line
2476 between them, in the style requested.
2478 Here is an example showing the different line styles available,
2479 and how to tune them.
2481 @lilypond[relative=2,ragged-right,verbatim,fragment]
2483 \once \override Glissando #'style = #'dashed-line
2485 \override Glissando #'style = #'dotted-line
2487 \override Glissando #'style = #'zigzag
2489 \override Glissando #'style = #'trill
2493 The locations of the end-points of the spanner are computed
2494 on-the-fly for every graphic object, but it is possible to
2498 @lilypond[relative=2,ragged-right,verbatim,fragment]
2500 \once \override Glissando #'bound-details #'right #'Y = #-2
2504 The value for @code{Y} is set to @code{-2} for the right end
2505 point. The left side may be similarly adjusted by specifying
2506 @code{left} instead of @code{right}.
2508 If @code{Y} is not set, the value is computed from the vertical
2509 position of the left and right attachment points of the spanner.
2511 Other adjustments of spanners are possible, for details, see
2514 @node Rotating objects
2515 @subsection Rotating objects
2517 Both layout objects and elements of markup text can be rotated by
2518 any angle about any point, but the method of doing so differs.
2521 * Rotating layout objects::
2525 @node Rotating layout objects
2526 @unnumberedsubsubsec Rotating layout objects
2528 @cindex rotating objects
2529 @cindex objects, rotating
2531 All layout objects which support the @code{grob-interface} can be
2532 rotated by setting their @code{rotation} property. This takes a
2533 list of three items: the angle of rotation counter-clockwise,
2534 and the x and y coordinates of the point relative to the object's
2535 reference point about which the rotation is to be performed. The
2536 angle of rotation is specified in degrees and the coordinates in
2539 The angle of rotation and the coordinates of the rotation point must
2540 be determined by trial and error.
2542 @cindex hairpins, angled
2543 @cindex angled hairpins
2545 There are only a few situations where the rotation of layout
2546 objects is useful; the following example shows one situation where
2549 @lilypond[quote,verbatim,relative=1]
2551 \override Hairpin #'rotation = #'(20 -1 0)
2555 @node Rotating markup
2556 @unnumberedsubsubsec Rotating markup
2558 All markup text can be rotated to lie at any angle by prefixing it
2559 with the @code{\rotate} command. The command takes two arguments:
2560 the angle of rotation in degrees counter-clockwise and the text to
2561 be rotated. The extents of the text are not rotated: they take
2562 their values from the extremes of the x and y coordinates of the
2563 rotated text. In the following example the
2564 @code{outside-staff-priority} property for text is set to @code{#f}
2565 to disable the automatic collision avoidance, which would push some
2566 of the text too high.
2568 @lilypond[quote,verbatim,relative=1]
2569 \override TextScript #'outside-staff-priority = ##f
2570 g4^\markup { \rotate #30 "a G" }
2571 b^\markup { \rotate #30 "a B" }
2572 des^\markup { \rotate #30 "a D-Flat" }
2573 fis^\markup { \rotate #30 "an F-Sharp" }
2576 @node Advanced tweaks
2577 @section Advanced tweaks
2580 * Aligning objects::
2581 * Vertical grouping of grobs::
2582 * Modifying stencils::
2583 * Modifying shapes::
2586 @node Aligning objects
2587 @subsection Aligning objects
2589 Graphical objects which support the @code{self-alignment-interface} and/or
2590 the @code{side-position-interface} can be
2591 aligned to a previously placed object in a variety of ways. For a list of these objects, see
2592 @rinternals{self-alignment-interface} and @rinternals{side-position-interface}.
2594 All graphical objects have a reference point, a horizontal extent and a
2595 vertical extent. The horizontal extent is a pair of numbers
2596 giving the displacements from the reference point of the left and
2597 right edges, displacements to the left being negative. The
2598 vertical extent is a pair of numbers giving the displacement from
2599 the reference point to the bottom and top edges, displacements down
2602 An object's position on a staff is given by the values of the
2603 @code{X-offset} and @code{Y-offset} properties. The value of
2604 @code{X-offset} gives the displacement from the x coordinate of
2605 the reference point of the parent object, and the value of
2606 @code{Y-offset} gives the displacement from the center line of the
2607 staff. The values of @code{X-offset} and
2608 @code{Y-offset} may be set directly or may be set to be calculated
2609 by procedures in order to achieve alignment with the parent object
2612 @warning{Many objects have special positioning considerations which
2613 cause any setting of @code{X-offset} or @code{Y-offset} to be
2614 ignored or modified, even though the object supports the
2615 @code{self-alignment-interface}.}
2617 For example, an accidental can be repositioned
2618 vertically by setting @code{Y-offset} but any changes to
2619 @code{X-offset} have no effect.
2621 Rehearsal marks may be aligned with
2622 breakable objects such as bar lines, clef symbols, time signature
2623 symbols and key signatures. There are special properties to be
2624 found in the @code{break-aligned-interface} for positioning rehearsal
2625 marks on such objects.
2628 * Setting @code{X-offset} and @code{Y-offset} directly::
2629 * Using the @code{side-position-interface}::
2630 * Using the @code{self-alignment-interface}::
2631 * Using the @code{break-aligned-interface}::
2634 @node Setting @code{X-offset} and @code{Y-offset} directly
2635 @unnumberedsubsubsec Setting @code{X-offset} and @code{Y-offset} directly
2637 Numerical values may be given to the @code{X-offset} and @code{Y-offset}
2638 properties of many objects. The following example shows three
2639 notes with the default fingering position and the positions with @code{X-offset}
2640 and @code{Y-offset} modified.
2642 @lilypond[verbatim,quote,relative=2]
2645 -\tweak #'X-offset #0
2646 -\tweak #'Y-offset #0
2649 -\tweak #'X-offset #-1
2650 -\tweak #'Y-offset #1
2656 @node Using the @code{side-position-interface}
2657 @unnumberedsubsubsec Using the @code{side-position-interface}
2659 An object which supports the @code{side-position-interface} can be
2660 placed next to its parent object so that
2661 the specified edges of the two objects touch. The object may be
2662 placed above, below, to the right or to the left of the parent.
2663 The parent cannot be specified; it is determined by the order of
2664 elements in the input stream. Most objects have the associated
2665 note head as their parent.
2667 The values of the @code{side-axis} and @code{direction} properties
2668 determine where the object is to be placed, as follows:
2670 @c TODO add an example of each to the table
2672 @multitable @columnfractions .3 .3 .3
2673 @headitem @code{side-axis} @tab @code{direction} @tab
2674 @headitem property @tab property @tab Placement
2676 @item @code{0} @tab @code{-1} @tab left
2677 @item @code{0} @tab @code{1} @tab right
2678 @item @code{1} @tab @code{-1} @tab below
2679 @item @code{1} @tab @code{1} @tab above
2683 When @code{side-axis} is @code{0}, @code{X-offset} should be set to
2684 the procedure @code{ly:side-position-interface::x-aligned-side}.
2685 This procedure will return the correct value of @code{X-offset} to
2686 place the object to the left or right side of the parent according
2687 to value of @code{direction}.
2689 When @code{side-axis} is @code{1}, @code{Y-offset} should be set to
2690 the procedure @code{ly:side-position-interface::y-aligned-side}.
2691 This procedure will return the correct value of @code{Y-offset} to
2692 place the object to the top or bottom of the parent according
2693 to value of @code{direction}.
2695 @c TODO Add examples
2697 @node Using the @code{self-alignment-interface}
2698 @unnumberedsubsubsec Using the @code{self-alignment-interface}
2700 @emph{Self-aligning objects horizontally}
2702 The horizontal alignment of an object which supports the
2703 @code{self-alignment-interface} is controlled by the value of
2704 the @code{self-alignment-X} property, provided the object's
2705 @code{X-offset} property is set to
2706 @code{ly:self-alignment-interface::x-aligned-on-self}.
2707 @code{self-alignment-X} may be given any
2708 real value, in units of half the total X extent of the
2709 object. Negative values move the object to the right, positive
2710 to the left. A value of @code{0} centers the object on the
2711 reference point of its parent, a value of @code{-1} aligns the
2712 left edge of the object on the reference point of its parent,
2713 and a value of @code{1} aligns the right edge of the object on the
2714 reference point of its parent. The symbols @code{LEFT},
2715 @code{CENTER} and @code{RIGHT} may be used instead of the values
2716 @code{-1, 0, 1} respectively.
2718 Normally the @code{\override} command would be used to modify the
2719 value of @code{self-alignment-X}, but the @code{\tweak} command
2720 can be used to separately align several annotations on a single
2723 @lilypond[quote,verbatim,relative=1]
2725 -\tweak #'self-alignment-X #-1
2727 -\tweak #'self-alignment-X #0
2729 -\tweak #'self-alignment-X #RIGHT
2731 -\tweak #'self-alignment-X #-2.5
2732 ^"aligned further to the right"
2735 @emph{Self-aligning objects vertically}
2737 Objects may be aligned vertically in an analogous way to aligning
2738 them horizontally if the @code{Y-offset} property is set to
2739 @code{ly:self-alignment-interface::y-aligned-on-self}. However,
2740 other mechanisms are often involved in vertical alignment: the
2741 value of @code{Y-offset} is just one variable taken into account.
2742 This may make adjusting the value of some objects tricky.
2743 The units are just half the vertical extent of the object, which
2744 is usually quite small, so quite large numbers may be required.
2745 A value of @code{-1} aligns the lower edge of the object with
2746 the reference point of the parent object, a value of @code{0}
2747 aligns the center of the object with the reference point of the
2748 parent, and a value of @code{1} aligns the top edge of the object
2749 with the reference point of the parent. The symbols @code{DOWN},
2750 @code{CENTER}, @code{UP} may be substituted for @code{-1, 0, 1}
2753 @emph{Self-aligning objects in both directions}
2755 By setting both @code{X-offset} and @code{Y-offset}, an object may
2756 be aligned in both directions simultaneously.
2758 The following example shows how to adjust a fingering mark so
2759 that it nestles close to the note head.
2761 @lilypond[quote,verbatim,relative=2]
2763 -\tweak #'self-alignment-X #0.5 % move horizontally left
2764 -\tweak #'Y-offset #ly:self-alignment-interface::y-aligned-on-self
2765 -\tweak #'self-alignment-Y #-1 % move vertically up
2770 @unnumberedsubsubsec Using the @code{aligned-on-parent} procedures
2772 @c Cannot document as they do not seem to operate consistently on all objects -td
2773 @c TODO investigate further
2775 The @code{aligned-on-parent} procedures are used in the same way
2776 as the @code{aligned-on-self} procedures, they difference being
2777 that they permit an object to be aligned with the @emph{edges} of
2778 the parent rather than the parent's reference point. The following
2779 example shows the difference:
2783 @lilypond[verbatim,quote]
2789 @unnumberedsubsubsec Using the @code{centered-on-parent} procedures
2791 @c Cannot document as they do not seem to operate consistently on all objects -td
2792 @c TODO investigate further
2796 @c TODO The align-interface, BassFigureAlignment and VerticalAlignment
2798 @node Using the @code{break-aligned-interface}
2799 @unnumberedsubsubsec Using the @code{break-aligned-interface}
2801 Rehearsal marks may be aligned with notation objects other
2802 than bar lines. These objects include @code{ambitus},
2803 @code{breathing-sign}, @code{clef}, @code{custos}, @code{staff-bar},
2804 @code{left-edge}, @code{key-cancellation}, @code{key-signature}, and
2805 @code{time-signature}.
2807 By default, rehearsal marks will be horizontally centered above the
2810 @lilypond[verbatim,quote,relative=1]
2812 % the RehearsalMark will be centered above the Clef
2813 \override Score.RehearsalMark #'break-align-symbols = #'(clef)
2818 % the RehearsalMark will be centered above the TimeSignature
2819 \override Score.RehearsalMark #'break-align-symbols = #'(time-signature)
2827 The alignment of the rehearsal mark relative to the notation object
2828 can be changed, as shown in the following example. In a score with
2829 multiple staves, this setting should be done for all the staves.
2831 @lilypond[verbatim,quote,relative=1]
2832 % The RehearsalMark will be centered above the KeySignature
2833 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
2839 % The RehearsalMark will be aligned with the left edge of the KeySignature
2840 \once \override Score.KeySignature #'break-align-anchor-alignment = #LEFT
2844 % The RehearsalMark will be aligned with the right edge of the KeySignature
2845 \once \override Score.KeySignature #'break-align-anchor-alignment = #RIGHT
2851 The rehearsal mark can also be offset to the right or left of the left edge
2852 by an arbitrary amount. The units are staff-spaces:
2854 @lilypond[verbatim,quote,relative=1]
2855 % The RehearsalMark will be aligned with the left edge of the KeySignature
2856 % and then shifted right by 3.5 staff-spaces
2857 \override Score.RehearsalMark #'break-align-symbols = #'(key-signature)
2858 \once \override Score.KeySignature #'break-align-anchor = #3.5
2862 % The RehearsalMark will be aligned with the left edge of the KeySignature
2863 % and then shifted left by 2 staff-spaces
2864 \once \override Score.KeySignature #'break-align-anchor = #-2
2872 @node Vertical grouping of grobs
2873 @subsection Vertical grouping of grobs
2875 @c FIXME Expand this section
2877 The VerticalAlignment and VerticalAxisGroup grobs work together.
2878 VerticalAxisGroup groups together different grobs like Staff, Lyrics,
2879 etc. VerticalAlignment then vertically aligns the different grobs
2880 grouped together by VerticalAxisGroup. There is usually only one
2881 VerticalAlignment per score but every Staff, Lyrics, etc. has its own
2885 @node Modifying stencils
2886 @subsection Modifying stencils
2888 All layout objects have a @code{stencil} property which is part of
2889 the @code{grob-interface}. By default, this property is usually
2890 set to a function specific to the object that is tailor-made to
2891 render the symbol which represents it in the output. For example,
2892 the standard setting for the @code{stencil} property of the
2893 @code{MultiMeasureRest} object is @code{ly:multi-measure-rest::print}.
2895 The standard symbol for any object can be replaced by modifying the
2896 @code{stencil} property to reference a different, specially-written,
2897 procedure. This requires a high level of knowledge of the internal
2898 workings of LilyPond, but there is an easier way which can often
2899 produce adequate results.
2901 This is to set the @code{stencil} property to the procedure which
2902 prints text -- @code{ly:text-interface::print} -- and to add a
2903 @code{text} property to the object which is set to contain the
2904 markup text which produces the required symbol. Due to the
2905 flexibility of markup, much can be achieved -- see in particular
2906 @ref{Graphic notation inside markup}.
2908 The following example demonstrates this by changing the note head
2909 symbol to a cross within a circle.
2911 @lilypond[verbatim,quote]
2913 \once \override NoteHead #'stencil = #ly:text-interface::print
2914 \once \override NoteHead #'text = \markup {
2916 \halign #-0.7 \draw-circle #0.85 #0.2 ##f
2917 \musicglyph #"noteheads.s2cross"
2925 Any of the glyphs in the feta Font can be supplied to the
2926 @code{\musicglyph} markup command -- see @ref{The Feta font}.
2928 @c TODO Add inserting eps files or ref to later
2930 @c TODO Add inserting Postscript or ref to later
2935 @ref{Graphic notation inside markup},
2936 @ref{Formatting text},
2937 @ref{Text markup commands},
2938 @ref{The Feta font}.
2941 @node Modifying shapes
2942 @subsection Modifying shapes
2945 * Modifying ties and slurs::
2948 @node Modifying ties and slurs
2949 @unnumberedsubsubsec Modifying ties and slurs
2951 Ties, slurs and phrasing slurs are drawn as third-order Bézier
2952 curves. If the shape of the tie or slur which is calculated
2953 automatically is not optimum, the shape may be modified manually by
2954 explicitly specifying the four control points required to define
2955 a third-order Bézier curve.
2957 Third-order or cubic Bézier curves are defined by four control
2958 points. The first and fourth control points are precisely the
2959 starting and ending points of the curve. The intermediate two
2960 control points define the shape. Animations showing how the curve
2961 is drawn can be found on the web, but the following description
2962 may be helpful. The curve starts from the first control point
2963 heading directly towards the second, gradually bending over to
2964 head towards the third and continuing to bend over to head towards
2965 the fourth, arriving there travelling directly from the third
2966 control point. The curve is entirely contained in the
2967 quadrilateral defined by the four control points.
2969 Here is an example of a case where the tie is not optimum, and
2970 where @code{\tieDown} would not help.
2972 @lilypond[verbatim,quote,relative=1]
2976 { r4 <g c,> <g c,> <g c,> }
2980 One way of improving this tie is to manually modify its control
2983 The coordinates of the Bézier control points are specified in units
2984 of staff-spaces. The X@tie{}coordinate is relative to the reference
2985 point of the note to which the tie or slur is attached, and the
2986 Y@tie{}coordinate is relative to the staff center line. The
2987 coordinates are entered as a list of four pairs of decimal numbers
2988 (reals). One approach is to estimate the coordinates of the two
2989 end points, and then guess the two intermediate points. The optimum
2990 values are then found by trial and error.
2992 It is useful to remember that a symmetric curve requires symmetric
2993 control points, and that Bézier curves have the useful property that
2994 transformations of the curve such as translation, rotation and
2995 scaling can be achieved by applying the same transformation to the
2996 curve's control points.
2998 For the example above the following override gives a satisfactory
3001 @lilypond[verbatim,quote,relative=1]
3004 #'control-points = #'((1 . -1) (3 . 0.6) (12.5 . 0.6) (14.5 . -1))
3007 { r4 <g c,> <g c,> <g c,>4 }
3013 It is not possible to modify shapes of ties or slurs by changing
3014 the @code{control-points} property if there are more than one at
3015 the same musical moment, not even by using the @code{\tweak}
3020 @node Discussion of specific tweaks
3021 @section Discussion of specific tweaks
3023 @c TODO What should go in here?