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LilyPond backend properties

X-extent-callback (procedure):

procedure taking an grob and axis argument, returning a number-pair. The return value is the extent of the grob.

X-offset-callbacks (list):

list of functions, each taking an grob and axis argument. The function determine the position relative to this grob's parent. The last one in the list is called first.

Y-extent-callback (procedure):

see X-extent-callback.

Y-offset-callbacks (list):

see X-offset-callbacks.

after-line-breaking-callback (procedure):

Procedure taking a grob as argument. This procedure is called (using dependency resolution) after line breaking. Return value is ignored.

align (number):

the alignment of the text, 0 is horizontal, 1 is vertical.

align-dir (direction):

Which side to align? -1: left side, 0: around center of width, 1: right side.

alignment (number):

alignment of lyrics on notehead, -1 is LEFT, 0 is CENTRE, 1 is RIGHT .

alignment-done (boolean):

boolean to administrate whether we've done the alignment already (to ensure that the process is done only once).

all-elements (list):

list of all grobs in this line. Needed for protecting grobs from GC.

arch-angle (number):

turning angle of the hook of a system brace

arch-height (number):

height of the hook of a system brace.

arch-thick (number):

thickness of the hook of system brace.

arch-width (number):

width of the hook of a system brace.

arithmetic-basicspace (number):

see spacing-spanner-interface.

arithmetic-multiplier (number):

see spacing-spanner-interface.

attachment (pair):

cons of symbols, '(LEFT-TYPE . RIGHT-TYPE), where both types may be alongside-stem, stem, head or loose-end.

attachment-offset (pair):

cons of offsets, '(LEFT-offset . RIGHT-offset). This offset is added to the attachments to prevent ugly slurs. [fixme: we need more documentation here]. .

auto-knee-gap (number or boolean):

the minimal smallest gap between two adjacent beamed chords for which beam will create auto-knees. Set to false for no auto knees.

axes (list):

list of axis numbers. In the case of alignment grobs, this should contain only one number.

bar-line-collapse-height (number):

Minimum height of system start delimiter bar-line glyphs. If equal or smaller, the bar-line is removed.

bar-size (number):

size of a bar line.

bar-size-procedure (procedure):

Procedure that computes the size of a bar line.

bars (list):

list of barline pointers.

baseline-skip (number):

Baseline skip to use for multiple lines of text.

bass (list):

musical-pitch, optional.

beam (grob (GRaphical OBject)):

pointer to the beam, if applicable.

beam-space-function (procedure):

function returning space given multiplicity.

beam-thickness (number):

thickness, measured in staffspace.

beam-width (number):

width of the tremolo sign.

beamAuto (boolean):

enable autobeaming?.

beamed-lengths (list):

list of stem lengths given beam multiplicity .

beamed-minimum-lengths (list):

list of minimum stem lengths given beam multiplicity.

beamed-stem-shorten (number):

shorten beamed stems in forced direction.

beaming (pair of numbers):

number of beams extending to left and right.

beams (list):

list of beam ptrs.

beautiful (number):

number that dictates when a slur should be de-uglyfied. It correlates with the enclosed area between noteheads and slurs. A value of 0.1 yields only undisturbed slurs, a value of 5 will tolerate quite high blown slurs.

before-grace-spacing-factor (number):

stretch space this much if there are grace notes before the column.

before-line-breaking-callback (procedure):

Procedure taking grob as argument. This procedure is called (using dependency resolution) before line breaking, but after generating discretionary items. Return value is ignored.

before-musical-spacing-factor (number):

space before musical columns (eg. taken by accidentals) get this much stretched when they follow a musical column, in absence of grace notes. 0.0 means no extra space (accidentals are ignored).

begin-alignment (number):

proportion of lyric length from beginning to align with note-head for left-aligned lyrics.

between-system-string (string):

string to dump between two systems. Useful for forcing pagebreaks.

bounded-by-me (list):

list of spanners that have this column as start/begin point. Only columns that have grobs or act as bounds are spaced.

brace-collapse-height (number):

Minimum height of system start delimiter brace glyphs. If equal or smaller, the brace is removed.

bracket-collapse-height (number):

Minimum height of system start delimiter bracket glyphs. If equal or smaller, the bracket is removed.

bracket-thick (number):

width of a system start bracket. .

break-align-symbol (symbol):

the index in the spacing table (symbol) of the to be aligned item.

break-glyph-function (procedure):

function taking glyph and break-direction, returning the glyph at a line break.

breakable (boolean):

boolean indicating if this is a breakable item (clef, barline, key sig, etc.).

c0-position (integer):

integer indicating the position of central C.

center-element (grob (GRaphical OBject)):

grob which will be at the center of the group after aligning (when using Align_interface::center_on_element). .

column-space-strength (number):

relative strength of space following breakable columns (eg. prefatory matter).

columns (list):

list of grobs, typically containing paper-columns, list of note-columns.

contains-grace (boolean):

Used to widen entries for grace notes.

control-points (list):

List of 4 offsets (number-pairs) that form control points for the tie/slur shape.

damping (integer):

amount of beam slope damping should beam slope be damped? 0: no, 1: yes, 100000: horizontal beams .

dash-length (number):

the length of a dash.

dash-period (number):

the length of one dash + white space.

dashed (number):

[FIXME: use dash-period/dash length; see text-spanner] number representing the length of the dashes.

de-uglify-parameters (list):

list of 3 real constants. They define the valid areas for the middle control points. Used in de_uglyfy. They are a bit empirical.

delta-y (number):

amount of ascension.

dependencies (list):

list of score-grob pointers that indicate who to compute first for certain global passes.

details (list):

alist of parameters for detailed grob behavior.

dir-forced (boolean):

set if direction has been forced; read by Beam.

dir-function (procedure):

function of type (count total)->direction. Default value: beam-dir-majority, also available: beam-dir-mean, beam-dir-median.

The ways to calculate the direction of a beam work as follows:

majority

number count of up or down notes

mean

mean center distance of all notes

median

mean centre distance weighted per note

dir-list (list):

list of stem directions, needed for optical spacing correction.

direction (direction):

up or down, left or right?.

direction-source (grob (GRaphical OBject)):

in case side-relative-direction is set, which grob to get the direction from .

dot (grob (GRaphical OBject)):

reference to Dots object.

dot-count (integer):

number of dots.

duration-log (integer):

2-log of the notehead duration, i.e. 0=whole note, 1 = half note, etc.

dy (number):

set by beam: vertical travel height

edge-height (pair):

a cons that specifies the heights of the vertical egdes '(LEFT-height . RIGHT-height).

edge-text (pair):

a cons that specifies the texts to be set at the edges '(LEFT-text . RIGHT-text).

elements (list):

list of grobs, type depending on the Grob where this is set in.

end-alignment (number):

proportion of lyric length from end to align with note-head for right-aligned lyrics.

expand-limit (integer):

maximum number of measures expanded in church rests.

extra-extent-X (pair of numbers):

enlarge in X dimension by this much, measured in staff space.

extra-extent-Y (pair of numbers):

see extra-extent-Y.

extra-offset (pair of numbers):

pair of reals (a cons) forcing an extra offset before outputting. extra-offset is added just before `printing' the grob, so the typesetting engine is completely oblivious to it.

extra-space (pair of numbers):

pair of distances (cons LEFT RIGHT).

extremity-offset-alist (list):

an alist (attachment stem-dir*dir slur-dir*dir) -> offset. The offset adds to the centre of the notehead, or stem.

extremity-rules (list):

an alist (procedure slur dir) -> attachment to determine the attachment (see above). If procedure returns #t, attachment is used. Otherwise, the next procedure is tried.

flag-style (string):

style for flag (hook of a stem).

flag-width-function (procedure):

Procedure that computes the width of a half-beam (a non-connecting beam.).

font-design-size (number):

partial font definition: exact font size in points FIXME: should override font-relative-size.

font-family (symbol):

partial font definition: music roman braces dynamic math ...

font-name (symbol):

partial font definition: base name of font file FIXME: should override other partials.

font-relative-size (number):

partial font definition: the relative size compared the `normal' size. 0 is style-sheet's normal size, -1 is smaller, +1 is bigger, -1 is smaller.

font-series (symbol):

partial font definition: medium, bold.

font-shape (symbol):

partial font definition: upright or italic.

font-style (symbol):

a precooked set of font definitions, eg. finger volta timesig mark script large Large dynamic.

force-hshift (number):

amount of collision_note_width that overides automatic collision settings. This is used by note-collision-interface.

forced-distance (number):

forced distance for an alignment.

fraction (pair of numbers):

fraction of a time signature.

full-size-change (boolean):

if set, don't make a change clef smaller.

gap (number):

Size of a gap in a variable symbol.

glyph (symbol):

a string determining what (style) of glyph is typeset. Valid choices depend on the function that is reading this property. .

glyph-name (string):

a name of character within font.

grow-direction (direction):

crescendo or decrescendo?.

hair-thickness (number):

thickness, measured in stafflinethickness.

heads (pair):

list of note heads,

FIXME: in Tie this is a pair of grob pointers, pointing to the two heads of the tie.

.

height (number):

in staffspace.

height-quants (procedure):

function of type (beam staff-line-thickness) -> list of quants. Default value: default-beam-dy-quants. .

horizontal-shift (integer):

integer that identifies ranking of note-column for horizontal shifting. This is used by note-collision-interface.

horizontal-space (number):

amount of space to add after a note (in staff-space).

ideal-distances (list):

(OBJ . (DIST . STRENGTH)) pairs.

ignore-length-mismatch (boolean):

if #t, stanzas with shorter lyrics can be moved away from their respective note-head by the lyric alignment code.

interfaces (list):

list of symbols indicating the interfaces supported by this object. Is initialized from the meta field.

inversion (list):

musical-pitch, optional.

invisible-staff (boolean):

is staff invisible?

items-worth-living (list):

list of interesting items. If empty in a particular system, clear that system.

kern (number):

amount of extra white space to add.

For text, this is `relative'(?) to the current alignment.

For barline, space after a thick line.

layer (number):

The output layer [0..2]. The default is 1.

left-padding (number):

space left of accs.

length (number):

Stem length for unbeamed stems, only for user override.

lengths (list):

Stem length given multiplicity of flag.

line-count (integer):

Number of staff lines.

line-thickness (number):

the thickness[stafflinethickness] of the line.

lookup (symbol):

lookup method: 'value for plain text, 'name for character-name.

magnify (number):

the magnification factor. FIXME: doesn't work for feta fonts.

maximum-duration-for-spacing (moment):

space as if a duration of this type is available in this measure.

maximum-length (number):

don't make Grob longer than this

maximum-rest-count (integer):

kill off rests so we don't more than this number left.

merge-differently-dotted (boolean):

Merge noteheads in collisions, even if they have a different number of dots. This normal notation for some types of polyphonic music. The value of this setting is used by note-collision-interface .

minimum-distance (number):

minimum distance between notes and rests.

minimum-distances (list):

list of rods (ie. (OBJ . DIST) pairs).

minimum-extent-X (pair of numbers):

minimum size in X dimension, measured in staff space.

minimum-extent-Y (pair of numbers):

see minimum-extent-Y.

minimum-length (number):

try to make the Grob at least this long.

Also works as a scaling parameter for the length of hyphen. .

minimum-space (number):

minimum distance that the victim should move (after padding).

FIXME: also pair? (cons LEFT RIGHT)

minimum-width (number):

minimum-width of rest symbol, in staffspace.

molecule-callback (procedure):

Function taking grob as argument, returning a Scheme encoded Molecule.

neutral-direction (direction):

Where to go if we're in the middle of the staff.

new-accidentals (list):

list of (pitch, accidental) pairs.

no-spacing-rods (boolean):

read from grobs: boolean that makes Separation_item ignore this item (MOVE ME TO ITEM).

no-stem-extend (boolean):

should stem not be extended to middle staff line?.

non-default (boolean):

not set because of existence of a bar?.

note-character (string):

character to print in a note head.

note-width (number):

unit for horizontal translation, measured in staff-space.

number-gap (number):

size of the gap for the number in a tuplet.

old-accidentals (list):

list of (pitch, accidental) pairs.

origin (input location):

location in input file of the definition.

outer-stem-length-limit (number):

catch suspect beam slopes, set slope to zero if outer stem is lengthened more than this (in staffspace).

padding (number):

add this much extra space between objects that are next to each other.

parallel-beam (boolean):

internal: true if there is a beam just as wide as the bracket .

pitches (list):

list of musical-pitch.

raise (number):

height for text to be raised (a negative value lowers the text.

right-padding (number):

space right of accs.

right-trim-amount (number):

shortening of the lyric extender on the right.

script-priority (number):

A sorting key that determines in what order a script is within a stack of scripts.

self-alignment-X (number):

real number: -1 = left aligned, 0 = center, 1 right-aligned in X direction.

Set to an grob pointer, if you want that grob to be the center. In this case, the center grob should have this object as a reference point. .

self-alignment-Y (number):

like self-alignment-X but for Y axis.

shortest-playing-duration (moment):

duration of the shortest playing in that column.

shortest-starter-duration (moment):

duration of the shortest notes that starts exactly in this column.

side-relative-direction (direction):

if set: get the direction from a different object, and multiply by this.

side-support (list):

the support, a list of grobs.

slope (number):

some kind of slope

slope-limit (number):

set slope to zero if slope is running away steeper than this.

space-alist (list):

Alist of break align spacing tuples. See basic-property.scm

space-function (procedure):

function of type multiplicity -> real (in staffspace).

spacing-procedure (procedure):

procedure taking grob as argument. This is called after before-line-breaking-callback, but before the actual line breaking itself. Return value is ignored.

stacking-dir (direction):

stack contents of grobs in which direction ?.

staff-position (number):

vertical position in staff spaces, counted from the middle line.

staff-space (number):

Amount of line leading relative to global staffspace.

staff-symbol (boolean):

the staff symbol grob that we're in.

staffline-clearance (number):

don't get closer than this to stafflines.

stem (grob (GRaphical OBject)):

pointer to Stem object.

stem-attachment-function (procedure):

Where does the stem attach to the notehead? Function takes a symbol argument being the style. It returns a (X . Y) pair, specifying location in terms of note head bounding box.

stem-end-position (number):

Where does the stem end (the end is opposite to the support-head.

stem-length (number):

length of stem.

stem-shorten (list):

shorten stems in forced directions given flag multiplicity.

stem-spacing-correction (number):

optical correction amount.

stems (list):

list of stem objects, corresponding to the notes that the arpeggio has to be before.

stretch-distance (pair of numbers):

pair of distances.

style (symbol):

a string determining what style of glyph is typeset. Valid choices depend on the function that is reading this property. .

support-head (grob (GRaphical OBject)):

the note head at one end of the stem.

text (markup (list or string)):

Scheme markup text. It is defined as follows:

text: string | (head? text+)
head: markup | (markup+)
markup-item: property | abbrev
property: (key . value)
abbrev: columns lines roman music bold italic named super sub overstrike text
        finger volta timesig mmrest mark script large Large dynamic

The following abbreviations are currently defined:

columns

horizontal mode: set all text on one line (default)

lines

vertical mode: set every text on new line

roman

select roman font

music

select feta font, and lookup by character name

bold

select bold series

italic

select italic shape

named

lookup by character name

text

plain text lookup (by character value)

super

superscript

sub

subscript

overstrike

the next text or character overstrikes this one

finger

select fingering number fontstyle

volta

select volta number fontstyle

timesig

select time signature number fontstyle

mmrest

select multi measure rest number fontstyle

mark

select mark number fontstyle

script

select scriptsize roman fontstyle

large

select large roman fontstyle

Large

select Large roman fontstyle

dynamic

select dynamics fontstyle

.

thick (number):

thickness, in stafflinethickness.

thick-thickness (number):

thickness, measured in stafflinethickness.

thickness (number):

thickness, measured in stafflinethickness.

thin-kern (number):

space after a hair-line.

threshold (pair of numbers):

(cons MIN MAX), where MIN and MAX are dimensions in staffspace.

transparent (boolean):

This is almost the same as setting molecule-callback to #f, but this retains the dimensions of this grob, which means that you can erase grobs individually. .

tuplet-bracket-visibility (boolean or symbol):

This controls the visibility of the tuplet bracket. Setting it to false will prevent printing of the bracket. Setting the property to #'if-no-beam will make it print only if there is no beam associated with this tuplet bracket.

tuplet-number-visibility (boolean or symbol):

Like tuplet-bracket-visibility, but for the number.

type (symbol):

one of: line, dashed-line or dotted-line.

vertical-position-quant-function (procedure):

function of type (beam multiplicity dy staff-line-thickness) -> real. Default value: default-beam-y-quants, also available: beam-traditional-y-quants. .

visibility-lambda (procedure):

a function that takes the break direction and returns a cons of booleans containing (TRANSPARENT . EMPTY).

when (moment):

when does this column happen?.

word-space (number):

elongate left by this much (FIXME: cumbersome semantics).

x-gap (number):

horizontal gap between notehead and tie.

y (number):

set by beam: position of left edge.

y-free (number):

minimal vertical gap between slur and noteheads or stems.

y-offset (number):

extra vertical offset for ties away from the center line.

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Copyright (c) 1997--2001 Han-Wen Nienhuys and Jan Nieuwenhuizen.

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