Documentation/snippets/adding-indicators-to-staves-which-get-split-after-a-break.ly

   1 %% Do not edit this file; it is automatically
   2 %% generated from LSR http://lsr.dsi.unimi.it
   3 %% This file is in the public domain.
   4 \version "2.13.29"
   5
   6 \header {
   7   lsrtags = "staff-notation, vocal-music"
   8
   9   texidoc = "
  10 This snippet defines the @code{\\splitStaffBarLine} command, which adds
  11 arrows in north-east and south-east directions at a bar line, to denote
  12 that several voices sharing a staff will each continue on a staff of
  13 their own in the next system.
  14
  15 "
  16   doctitle = "Adding indicators to staves which get split after a break"
  17 } % begin verbatim
  18
  19 #(define-markup-command (arrow-at-angle layout props angle-deg length fill)
  20    (number? number? boolean?)
  21    (let* (
  22           ;; PI-OVER-180 and degrees->radians are taken from flag-styles.scm
  23           (PI-OVER-180 (/ (atan 1 1) 45))
  24           (degrees->radians (lambda (degrees) (* degrees PI-OVER-180)))
  25           (angle-rad (degrees->radians angle-deg))
  26           (target-x (* length (cos angle-rad)))
  27           (target-y (* length (sin angle-rad))))
  28      (interpret-markup layout props
  29                        (markup
  30                         #:translate (cons (/ target-x 2) (/ target-y 2))
  31                         #:rotate angle-deg
  32                         #:translate (cons (/ length -2) 0)
  33                         #:concat (#:draw-line (cons length 0)
  34                                               #:arrow-head X RIGHT fill)))))
  35
  36 splitStaffBarLineMarkup = \markup \with-dimensions #'(0 . 0) #'(0 . 0) {
  37   \combine
  38     \arrow-at-angle #45 #(sqrt 8) ##f
  39     \arrow-at-angle #-45 #(sqrt 8) ##f
  40 }
  41
  42 splitStaffBarLine = {
  43   \once \override Staff.BarLine #'stencil =
  44     #(lambda (grob)
  45        (ly:stencil-combine-at-edge
  46         (ly:bar-line::print grob)
  47         X RIGHT
  48         (grob-interpret-markup grob splitStaffBarLineMarkup)
  49         0 0))
  50   \break
  51 }
  52
  53 \paper {
  54   ragged-right = ##t
  55   short-indent = 5\mm
  56 }
  57
  58 \score {
  59   <<
  60     \new ChoirStaff <<
  61       \new Staff \with { instrumentName = #"High I + II" } {
  62         <<
  63           \repeat unfold 4 f''1
  64           \\
  65           \repeat unfold 4 d''1
  66         >>
  67         \splitStaffBarLine
  68       }
  69       \new Staff \with { instrumentName = #"Low" } {
  70         <<
  71           \repeat unfold 4 b'1
  72           \\
  73           \repeat unfold 4 g'1
  74         >>
  75       }
  76
  77       \new Staff \with { shortInstrumentName = #"H I" } {
  78         R1*4
  79         \repeat unfold 2 { r4 f''2 r4 } \repeat unfold 2 e''1
  80       }
  81       \new Staff \with { shortInstrumentName = #"H II" } {
  82         R1*4
  83         \repeat unfold 4 b'2 \repeat unfold 2 c''1
  84       }
  85       \new Staff \with { shortInstrumentName = #"L" } {
  86         R1*4
  87         <<
  88           \repeat unfold 4 g'1
  89           \\
  90           \repeat unfold 4 c'1
  91         >>
  92       }
  93     >>
  94   >>
  95   \layout {
  96     \context {
  97       \Staff \RemoveEmptyStaves
  98       \override VerticalAxisGroup #'remove-first = ##t
  99     }
 100   }
 101 }
 102