Doc: Add example of extending glissandi over repeats (2591)

diff --git a/Documentation/notation/expressive.itely b/Documentation/notation/expressive.itely
index 82614e6d2bfc70c2fd299912a7227dded9aacdae..1fb946b0178b9f96d7e63b2aad9a37a02ad95aa8 100644 (file)
--- a/Documentation/notation/expressive.itely
+++ b/Documentation/notation/expressive.itely
@@ -1099,6 +1099,9 @@ Different styles of glissandi can be created.  For details, see
 @lilypondfile[verbatim,quote,texidoc,doctitle]
 {making-glissandi-breakable.ly}
 
 @lilypondfile[verbatim,quote,texidoc,doctitle]
 {making-glissandi-breakable.ly}
 

+@lilypondfile[verbatim,quote,texidoc,doctitle]
+{extending-glissandi-across-repeats.ly}
+

 @seealso
 Music Glossary:
 @rglos{glissando}.
 @seealso
 Music Glossary:
 @rglos{glissando}.

diff --git a/Documentation/notation/repeats.itely b/Documentation/notation/repeats.itely
index 67317a670cc301ec4847a6b5782b3259bcb5a9b2..53da1bdf743b8e27e29cd35c72c1d4619f5f8351 100644 (file)
--- a/Documentation/notation/repeats.itely
+++ b/Documentation/notation/repeats.itely
@@ -318,8 +318,10 @@ Internals Reference:
 @cindex repeat and measure number
 @cindex timing information and repeats
 @cindex measure number and repeats
 @cindex repeat and measure number
 @cindex timing information and repeats
 @cindex measure number and repeats

-@cindex repeat and slur
-@cindex slur and repeat
+@cindex repeats and slur
+@cindex slur and repeats
+@cindex glissandi and repeats
+@cindex repeats and glissandi

 
 Slurs that span from a @code{\repeat} block into an
 @code{\alternative} block will only work for the first alternative
 
 Slurs that span from a @code{\repeat} block into an
 @code{\alternative} block will only work for the first alternative


@@ -334,6 +336,14 @@ are shown in @ref{Modifying ties and slurs}.
 Also, slurs cannot wrap around from the end of one
 alternative back to the beginning of the repeat.
 
 Also, slurs cannot wrap around from the end of one
 alternative back to the beginning of the repeat.
 

+Glissandi that span from a @code{\repeat} block into an
+@code{\alternative} block will only work for the first alternative
+ending.  The visual appearance of a continuing glissando in other
+alternative blocks may be indicated by coding a glissando starting
+on a hidden grace note.  For an example, see
+@qq{Extending glissandi across repeats} under Selected Snippets
+in @ref{Glissando}.
+

 If a repeat that begins with an incomplete measure has an
 @code{\alternative} block that contains modifications to the
 @code{measureLength} property, using @code{\unfoldRepeats} will
 If a repeat that begins with an incomplete measure has an
 @code{\alternative} block that contains modifications to the
 @code{measureLength} property, using @code{\unfoldRepeats} will

diff --git a/Documentation/snippets/extending-glissandi-across-repeats.ly b/Documentation/snippets/extending-glissandi-across-repeats.ly
new file mode 100644 (file)
index 0000000..629b657
--- /dev/null
+++ b/Documentation/snippets/extending-glissandi-across-repeats.ly
@@ -0,0 +1,69 @@
+% DO NOT EDIT this file manually; it is automatically
+% generated from Documentation\snippets\new
+% Make any changes in Documentation/snippets/new/
+% and then run scripts/auxiliar/makelsr.py
+%
+% This file is in the public domain.
+%% Note: this file works from version 2.17.6
+\version "2.17.6"
+
+\header {
+  lsrtags = "staff-notation, tweaks-and-overrides"
+  texidoc = "
+A glissando which extends into several @code{\\alternative} blocks
+can be simulated by adding a hidden grace note with a glissando
+at the start of each @code{\\alternative} block.  The grace note
+should be at the same pitch as the note which starts the initial
+glissando.  This is implemented here with a music function which
+takes the pitch of the grace note as its argument.
+
+Note that in polyphonic music the grace note must be matched with
+corresponding grace notes in all other voices.
+"
+  doctitle = "Extending glissandi across repeats"
+} % begin verbatim
+
+repeatGliss = #(define-music-function (parser location grace)
+  (ly:pitch?)
+  #{
+    % the next two lines ensure the glissando is long enough
+    % to be visible
+    \once \override Glissando.springs-and-rods
+      = #ly:spanner::set-spacing-rods
+    \once \override Glissando.minimum-length = #3.5
+    \once \hideNotes
+    \grace $grace \glissando
+  #})
+
+\score {
+  \relative c'' {
+    \repeat volta 3 { c4 d e f\glissando }
+    \alternative {
+      { g2 d }
+      { \repeatGliss f g2 e }
+      { \repeatGliss f e2 d }
+    }
+  }
+}
+
+music =  \relative c' {
+  \voiceOne
+  \repeat volta 2 {
+    g a b c\glissando
+  }
+  \alternative {
+    { d1 }
+    { \repeatGliss c e1 }
+  }
+}
+
+\score {
+  \new StaffGroup <<
+    \new Staff <<
+      \context Voice { \clef "G_8" \music }
+    >>
+    \new TabStaff  <<
+      \context TabVoice { \clef "moderntab" \music }
+    >>
+  >>
+}
\ No newline at end of file

diff --git a/Documentation/snippets/new/extending-glissandi-across-repeats.ly b/Documentation/snippets/new/extending-glissandi-across-repeats.ly
new file mode 100644 (file)
index 0000000..0c7496c
--- /dev/null
+++ b/Documentation/snippets/new/extending-glissandi-across-repeats.ly
@@ -0,0 +1,62 @@
+\version "2.17.6"
+
+\header {
+  lsrtags = "staff-notation, tweaks-and-overrides"
+  texidoc = "
+A glissando which extends into several @code{\alternative} blocks
+can be simulated by adding a hidden grace note with a glissando
+at the start of each @code{\alternative} block.  The grace note
+should be at the same pitch as the note which starts the initial
+glissando.  This is implemented here with a music function which
+takes the pitch of the grace note as its argument.
+
+Note that in polyphonic music the grace note must be matched with
+corresponding grace notes in all other voices.
+"
+  doctitle = "Extending glissandi across repeats"
+}
+
+repeatGliss = #(define-music-function (parser location grace)
+  (ly:pitch?)
+  #{
+    % the next two lines ensure the glissando is long enough
+    % to be visible
+    \once \override Glissando.springs-and-rods
+      = #ly:spanner::set-spacing-rods
+    \once \override Glissando.minimum-length = #3.5
+    \once \hideNotes
+    \grace $grace \glissando
+  #})
+
+\score {
+  \relative c'' {
+    \repeat volta 3 { c4 d e f\glissando }
+    \alternative {
+      { g2 d }
+      { \repeatGliss f g2 e }
+      { \repeatGliss f e2 d }
+    }
+  }
+}
+
+music =  \relative c' {
+  \voiceOne
+  \repeat volta 2 {
+    g a b c\glissando
+  }
+  \alternative {
+    { d1 }
+    { \repeatGliss c e1 }
+  }
+}
+
+\score {
+  \new StaffGroup <<
+    \new Staff <<
+      \context Voice { \clef "G_8" \music }
+    >>
+    \new TabStaff  <<
+      \context TabVoice { \clef "moderntab" \music }
+    >>
+  >>
+}
\ No newline at end of file