+++ /dev/null
-% 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 2.15.35
-\version "2.15.35"
-
-\header {
- lsrtags = "staff-notation, tweaks-and-overrides, contexts-and-engravers"
- texidoc = "This file defines and demonstrates a scheme engraver that
-connects stems across staves. The stem length need not be specified, as
-the code takes care of the variable distance between noteheads and staves."
- doctitle = "Stem cross staff engraver"
-} % begin verbatim
-
-
-%{
- A new stem (referred to as span in the code) is created to connect the
- original stems. The original stems are made transparent.
-
- The span is created as a child of the "root" stem, that is the stem
- connected to a notehead with the end that is not to be extended.
-
- Both stem directions are supported. Connecting more than two stems is
- possible.
-%}
-
-% Values are close enough to ignore the difference
-#(define (close-enough? x y)
- (< (abs (- x y)) 0.0001))
-
-% Combine a list of extents
-#(define (extent-combine extents)
- (if (pair? (cdr extents))
- (interval-union (car extents) (extent-combine (cdr extents)))
- (car extents)))
-
-% Check if the stem is connectable to the root
-#(define ((stem-connectable? ref root) stem)
- ; The root is always connectable to itself
- (or (eq? root stem)
- (and
- ; Horizontal positions of the stems must be almost the same
- (close-enough? (car (ly:grob-extent root ref X))
- (car (ly:grob-extent stem ref X)))
- ; The stem must be in the direction away from the root's notehead
- (positive? (* (ly:grob-property root 'direction)
- (- (car (ly:grob-extent stem ref Y))
- (car (ly:grob-extent root ref Y))))))))
-
-% Connect stems if we have at least one stems connectable to the root
-#(define (stem-span-stencil span)
- (let* ((system (ly:grob-system span))
- (root (ly:grob-parent span X))
- (stems (filter (stem-connectable? system root)
- (ly:grob-object span 'stems))))
- (if (<= 2 (length stems))
- (let* ((yextents (map (lambda (st)
- (ly:grob-extent st system Y)) stems))
- (yextent (extent-combine yextents))
- (layout (ly:grob-layout root))
- (blot (ly:output-def-lookup layout 'blot-diameter)))
- ; Hide spanned stems
- (map (lambda (st)
- (set! (ly:grob-property st 'transparent) #t))
- stems)
- ; Draw a nice looking stem with rounded corners
- (ly:round-filled-box (ly:grob-extent root root X) yextent blot))
- ; Nothing to connect, don't draw the span
- #f)))
-
-% Create a stem span as a child of the cross-staff stem (the root)
-#(define ((make-stem-span! stems trans) root)
- (let ((span (ly:engraver-make-grob trans 'Stem '())))
- (ly:grob-set-parent! span X root)
- (set! (ly:grob-object span 'stems) stems)
- ; Suppress positioning, the stem code is confused by this weird stem
- (set! (ly:grob-property span 'X-offset) 0)
- (set! (ly:grob-property span 'stencil) stem-span-stencil)))
-
-% Set cross-staff property of the stem to this function to connect it to
-% other stems automatically
-#(define (cross-staff-connect stem)
- #t)
-
-% Check if automatic connecting of the stem was requested. Stems connected
-% to cross-staff beams are cross-staff, but they should not be connected to
-% other stems just because of that.
-#(define (stem-is-root? stem)
- (eq? cross-staff-connect (ly:grob-property-data stem 'cross-staff)))
-
-% Create stem spans for cross-staff stems
-#(define (make-stem-spans! ctx stems trans)
- ; Cannot do extensive checks here, just make sure there are at least
- ; two stems at this musical moment
- (if (<= 2 (length stems))
- (let ((roots (filter stem-is-root? stems)))
- (map (make-stem-span! stems trans) roots))))
-
-% Connect cross-staff stems to the stems above in the system
-#(define (Span_stem_engraver ctx)
- (let ((stems '()))
- (make-engraver
- ; Record all stems for the given moment
- (acknowledgers
- ((stem-interface trans grob source)
- (set! stems (cons grob stems))))
- ; Process stems and reset the stem list to empty
- ((process-acknowledged trans)
- (make-stem-spans! ctx stems trans)
- (set! stems '())))))
-
-crossStaff =
-#(define-music-function (parser location notes) (ly:music?) #{
- \override Stem #'cross-staff = #cross-staff-connect
- $notes
- \revert Stem #'cross-staff
-#})
-
-\layout {
- \context {
- \StaffGroup
- \consists #Span_stem_engraver
- }
-}
-
-\parallelMusic #'(voiceA voiceB voiceC) {
- % Bar 1 - durations, beams, flags
- g'2 g'4 g'8 [ g'16 ] g'16 |
- \crossStaff { c'2 c'4 c'8 [ c'16 ] c'16 } |
- R1 |
-
- % Bar 2 - direction
- g'8 \stemDown g'8 \crossStaff g'8 \stemNeutral g'8 g'4 r4 |
- \crossStaff { c'8 \stemDown c'8 } c'8 \stemNeutral c'8 r4 r4 |
- c8 \stemDown c8 c8 \stemNeutral \crossStaff { c8 c4 c4 } |
-
- % Bar 3 - multiple voice styles
- << c''2 \\ \crossStaff d'2 \\ a'2 \\ \crossStaff f'2 >> g'2 |
- << b'2 \\ c'2 \\ g'2 \\ e'2 >> << e'2 \\ \\ \crossStaff c'2 >> |
- << \crossStaff b2 \\ c2 \\ \crossStaff g2 \\ e2 >> r2 |
-
- % Bar 4 - grace notes
- \grace g'8 a'2 \stemDown \crossStaff { \grace g'8 a'2 } \stemNeutral |
- \grace c'8 d'2 \stemDown \grace c'8 d'2 \stemNeutral |
- \crossStaff { \grace c8 d2 } \stemDown \grace c8 d2 \stemNeutral |
-
- % Bar 5 - cross-staff beams
- g'8 g'8 g'8 g'8 r2 |
- s1 |
- \crossStaff { c8 [ \change Staff=stafftwo c''8 ] }
- \change Staff=staffthree c8 [ \change Staff=stafftwo c''8 ] r2 |
-}
-
-\score {
- \new StaffGroup <<
- \new Staff = "staffone" <<
- \new Voice {
- \autoBeamOff \voiceA
- }
- >>
- \new Staff = "stafftwo" <<
- \new Voice {
- \autoBeamOff \voiceB
- }
- >>
- \new Staff = "staffthree" <<
- \new Voice {
- \autoBeamOff \clef bass \voiceC
- }
- >>
- >>
- \layout { }
-}
projects / lilypond.git / commitdiff