Hi David,
On Sat, Oct 11, 2014 at 4:45 PM, David Bellows <[email protected]>
wrote:
> >The attached function will work with more complex music expressions.
>
> Nicely done! I really like the greater flexibility achieved based on using
> ledger lines. Fortunately in this project I don't use chords so that's not
> a problem
>
>
Well, in any case the attached now works with chords :)
The rule is that an ottava is only applied if all of the notes within the
chord have at least a certain number of ledger lines.
I'm thinking there ought to be some sort of resistance-to-change factor
which overrules the strict this-many-ledger-lines-gets-an-ottava rule.
Otherwise, if you hop between chords and single notes, you can get more
ottavas than is comfortable to read.
The code for build-new-elts needs to be refactored a bit.
less fortunately is that I need it for the bassa as well. But I will look
> over the code and see if I can't figure it out for myself.
>
Yes, you could insert an expression into build-new-elts which would look at
the number of ledger lines and insert a (list (makeMusic 'OttavaMusic
'ottava-number -1)) to create the 8va bassa. Of course, you'd need one to
shut it off with (list (makeMusic 'OttavaMusic 'ottava-number 0)).
This will all be better once this thing has the ability to detect the
current clef. It looks like that's possible, because calling \clef ...
adds a 'PropertySet event to the mix, and 'clefMiddleCPosition (which the
ledger-line counter is designed to work with) is available.
Detecting the clef would be useful for 8va bassa, because it's never used
with treble clef (as I remember from Gardner Read).
Anyway, hope this is helpful.
--David
P.S. It's now \ottavate instead of \octavate
\version "2.19.10"
\header {
tagline = ##f
}
#(define (ledger-line-no middle-C-pos p)
"Returns the number of ledger-lines a pitch @var{p} will have with
middle C position @var{middle-C-pos} expressed as staff-steps from the
middle staff line."
(let* ((ps (ly:pitch-steps p))
(mid-staff-steps (- middle-C-pos))
(top-line (+ mid-staff-steps 4))
(bottom-line (- mid-staff-steps 4))
(above? (> ps top-line))
(below? (< ps bottom-line))
(steps-outside-staff
(cond
(below? (- ps bottom-line))
(above? (- ps top-line))
(else 0))))
(truncate (/ steps-outside-staff 2))))
ottavate =
#(define-music-function (parser location threshold mus)
(integer? ly:music?)
"Create an ottava for notes which have at least @var{threshold} ledger lines"
(let ((up-an-octave (list (make-music 'OttavaMusic 'ottava-number 1)))
(loco (list (make-music 'OttavaMusic 'ottava-number 0))))
(define (build-new-elts mus-expr new-expr start-loco? start-ottava?)
(if (null? mus-expr)
;; ensure that ottava does not extend past a localized
;; use of \octavate
(append new-expr loco)
(cond
((music-is-of-type? (car mus-expr) 'event-chord)
(cond
((and
start-ottava?
(every (lambda (p)
(>= (ledger-line-no -6 (ly:music-property p 'pitch)) threshold))
(ly:music-property (car mus-expr) 'elements)))
(build-new-elts
(cdr mus-expr)
(append
new-expr
up-an-octave
(list (car mus-expr)))
#t #f))
((and
start-loco?
(any (lambda (p)
(< (ledger-line-no -6 (ly:music-property p 'pitch)) threshold))
(ly:music-property (car mus-expr) 'elements)))
(build-new-elts
(cdr mus-expr)
(append
new-expr
loco
(list (car mus-expr)))
#f #t))
(else (build-new-elts
(cdr mus-expr)
(append new-expr (list (car mus-expr)))
#t #t))))
((music-is-of-type? (car mus-expr) 'note-event)
(let ((p (ly:music-property (car mus-expr) 'pitch)))
(cond
((and (ly:pitch? p)
start-ottava?
(>= (ledger-line-no -6 p) threshold))
(build-new-elts
(cdr mus-expr)
(append
new-expr
up-an-octave
(list (car mus-expr)))
#t #f))
((and (ly:pitch? p)
start-loco?
(< (ledger-line-no -6 p) threshold))
(build-new-elts
(cdr mus-expr)
(append
new-expr
loco
(list (car mus-expr)))
#f #t))
(else
(build-new-elts
(cdr mus-expr)
(append new-expr (list (car mus-expr)))
#t #t)))))
(else
(build-new-elts
(cdr mus-expr)
(append new-expr (list (car mus-expr)))
#t #t)))))
(define (recurse music)
(let ((elts (ly:music-property music 'elements))
(e (ly:music-property music 'element)))
(if (ly:music? e)
(recurse e))
(if (pair? elts)
(if (or
(any (lambda (elt) (music-is-of-type? elt 'note-event)) elts)
(any (lambda (elt) (music-is-of-type? elt 'event-chord)) elts))
(set! (ly:music-property music 'elements)
(build-new-elts elts '() #t #t))
(map recurse elts)))))
(recurse mus)
;(display-scheme-music mus)
mus))
%%%%%%%%%%% EXAMPLE %%%%%%%%%%%%
music = \relative c''' {
\repeat volta 2 {
a8 b c d e f g a
}
}
{
\ottavate #5 \music
\ottavate #4 \music
\ottavate #3 \music
\ottavate #2 \music
}
musictwo = \new PianoStaff <<
\new Staff { \music R1 }
\new Staff { \unfoldRepeats \transpose c e { \music } }
>>
{
\ottavate #3 \musictwo
}
musicthree =
\new PianoStaff <<
\relative c''' {
\new Staff {
\key g \major
\time 3/4
\new Voice {
<a c>8 <b d> <c e> <d fis> <e g> <fis a> <g b> <a c> <b d> <c e> <d fis> <e g>
<e g> <d fis> <c e> <b d> <a c> <g b> <fis a> <e g> <d fis> <c e> <b d> <a c>
}
}
}
\relative c'' {
\new Staff {
\key g \major
\new Voice {
<a c>8 <b d> <c e> <d fis> <e g> <fis a> <g b> <a c> <b d> <c e> <d fis> <e g>
<e g> <d fis> <c e> <b d> <a c> <g b> <fis a> <e g> <d fis> <c e> <b d> <a c>
}
}
}
>>
{
\ottavate #1 \musicthree
}
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