resolve merge

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

diff --git a/Documentation/snippets/adding-indicators-to-staves-which-get-split-after-a-break.ly b/Documentation/snippets/adding-indicators-to-staves-which-get-split-after-a-break.ly
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+%% DO NOT EDIT this file manually; it is automatically
+%% generated from LSR http://lsr.dsi.unimi.it
+%% Make any changes in LSR itself, or in Documentation/snippets/new/ ,
+%% and then run scripts/auxiliar/makelsr.py
+%%
+%% This file is in the public domain.
+\version "2.14.0"
+
+\header {
+  lsrtags = "staff-notation, vocal-music"
+
+  texidoc = "
+This snippet defines the @code{\\splitStaffBarLine} command, which adds
+arrows in north-east and south-east directions at a bar line, to denote
+that several voices sharing a staff will each continue on a staff of
+their own in the next system.
+
+"
+  doctitle = "Adding indicators to staves which get split after a break"
+} % begin verbatim
+
+#(define-markup-command (arrow-at-angle layout props angle-deg length fill)
+   (number? number? boolean?)
+   (let* (
+          ;; PI-OVER-180 and degrees->radians are taken from flag-styles.scm
+          (PI-OVER-180 (/ (atan 1 1) 45))
+          (degrees->radians (lambda (degrees) (* degrees PI-OVER-180)))
+          (angle-rad (degrees->radians angle-deg))
+          (target-x (* length (cos angle-rad)))
+          (target-y (* length (sin angle-rad))))
+     (interpret-markup layout props
+                       (markup
+                        #:translate (cons (/ target-x 2) (/ target-y 2))
+                        #:rotate angle-deg
+                        #:translate (cons (/ length -2) 0)
+                        #:concat (#:draw-line (cons length 0)
+                                              #:arrow-head X RIGHT fill)))))
+
+splitStaffBarLineMarkup = \markup \with-dimensions #'(0 . 0) #'(0 . 0) {
+  \combine
+    \arrow-at-angle #45 #(sqrt 8) ##f
+    \arrow-at-angle #-45 #(sqrt 8) ##f
+}
+
+splitStaffBarLine = {
+  \once \override Staff.BarLine #'stencil =
+    #(lambda (grob)
+       (ly:stencil-combine-at-edge
+        (ly:bar-line::print grob)
+        X RIGHT
+        (grob-interpret-markup grob splitStaffBarLineMarkup)
+        0 0))
+  \break
+}
+
+\paper {
+  ragged-right = ##t
+  short-indent = 5\mm
+}
+
+\score {
+  <<
+    \new ChoirStaff <<
+      \new Staff \with { instrumentName = #"High I + II" } {
+        <<
+          \repeat unfold 4 f''1
+          \\
+          \repeat unfold 4 d''1
+        >>
+        \splitStaffBarLine
+      }
+      \new Staff \with { instrumentName = #"Low" } {
+        <<
+          \repeat unfold 4 b'1
+          \\
+          \repeat unfold 4 g'1
+        >>
+      }
+
+      \new Staff \with { shortInstrumentName = #"H I" } {
+        R1*4
+        \repeat unfold 2 { r4 f''2 r4 } \repeat unfold 2 e''1
+      }
+      \new Staff \with { shortInstrumentName = #"H II" } {
+        R1*4
+        \repeat unfold 4 b'2 \repeat unfold 2 c''1
+      }
+      \new Staff \with { shortInstrumentName = #"L" } {
+        R1*4
+        <<
+          \repeat unfold 4 g'1
+          \\
+          \repeat unfold 4 c'1
+        >>
+      }
+    >>
+  >>
+  \layout {
+    \context {
+      \Staff \RemoveEmptyStaves
+      \override VerticalAxisGroup #'remove-first = ##t
+    }
+  }
+}
+