%% Generated by lilypond-book
%% Options: [exampleindent=10.16\mm,indent=0\mm,line-width=160\mm,paper-height=845.047\pt,paper-width=597.508\pt,papersize='(cons (* 597.508 pt) (* 845.047 pt)),quote]
\include "lilypond-book-preamble.ly"


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% Start cut-&-pastable-section
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#(ly:set-option 'eps-box-padding 3.000000)



\paper {
  #(set-paper-size '(cons (* 597.508 pt) (* 845.047 pt)))
  indent = 0\mm
  line-width = 160\mm
  % offset the left padding, also add 1mm as lilypond creates cropped
  % images with a little space on the right
  line-width = #(- line-width (* mm  3.000000) (* mm 1))
  line-width = 160\mm - 2.0 * 10.16\mm
  % offset the left padding, also add 1mm as lilypond creates cropped
  % images with a little space on the right
  line-width = #(- line-width (* mm  3.000000) (* mm 1))
}

\layout {
  
}




% ****************************************************************
% ly snippet:
% ****************************************************************
\sourcefilename "snippets/transposing-pitches-with-minimum-accidentals--smart--transpose.ly"
\sourcefileline 0
%% DO NOT EDIT this file manually; it was automatically
%% generated from the LilyPond Wiki
%% (https://wiki.lilypond.community).
%%
%% Make any changes in the Wiki itself, or in
%% `Documentation/snippets/new/`, then run
%% `scripts/auxiliar/makelsr.pl`.
%%
%% This file is in the public domain.

\version "2.24.0"

\header {
%% Translation of GIT committish: c043783aac6c35926d633aa2daf60ed4f2e7ca7a
  texidocfr = "
Cet exemple, grâce à un peu de code Scheme, donne la priorité aux
enharmoniques afin de limiter le nombre d'altérations supplémentaires.
La règle applicable est :

@itemize
@item
Les altérations doubles sont supprimées

@item
Si dièse -> Do

@item
Mi dièse -> Fa

@item
Do bémol -> Si

@item
Fa bémol -> Mi

@end itemize

Cette façon de procéder aboutit à plus d'enharmoniques naturelles.
"

  doctitlefr = "Transposition et réduction du nombre d'altérations accidentelles"

  categories = "Pitches, Scheme, Workaround"

  texidoc = "
This example uses some Scheme code to enforce enharmonic modifications
for notes in order to have the minimum number of accidentals. In this
case, the following rules apply:

@itemize
@item
double accidentals should be removed
@item
b sharp → c
@item
e sharp → f
@item
c flat → b
@item
f flat → e
@end itemize

In this manner, the most natural enharmonic notes are chosen.
"

  doctitle = "Transposing pitches with minimum accidentals (@qq{smart} transpose)"
} % begin verbatim


#(define (naturalize-pitch p)
   (let ((o (ly:pitch-octave p))
         ;; `ly:pitch-alteration` returns quarter tone steps.
         (a (* 4 (ly:pitch-alteration p)))
         (n (ly:pitch-notename p)))
     (cond
      ((and (> a 1)
            (or (eqv? n 6) (eqv? n 2)))
       (set! a (- a 2))
       (set! n (+ n 1)))
      ((and (< a -1)
            (or (eqv? n 0) (eqv? n 3)))
       (set! a (+ a 2))
       (set! n (- n 1))))
     (cond
      ((> a 2)
       (set! a (- a 4))
       (set! n (+ n 1)))
      ((< a -2)
       (set! a (+ a 4))
       (set! n (- n 1))))
     (when (< n 0)
       (set! o (- o 1))
       (set! n (+ n 7)))
     (when (> n 6)
       (set! o (+ o 1))
       (set! n (- n 7)))
     (ly:make-pitch o n (/ a 4))))

#(define (naturalize music)
   (let ((es (ly:music-property music 'elements))
         (e (ly:music-property music 'element))
         (p (ly:music-property music 'pitch)))
     (when (pair? es)
       (ly:music-set-property! music 'elements
                               (map naturalize es)))
     (when (ly:music? e)
       (ly:music-set-property! music 'element
                               (naturalize e)))
     (when (ly:pitch? p)
       (set! p (naturalize-pitch p))
       (ly:music-set-property! music 'pitch p))
     music))

naturalizeMusic =
#(define-music-function (m) (ly:music?)
   (naturalize m))

music = \relative c' { c4 d e g }

\new Staff {
  \transpose c ais { \music }
  \naturalizeMusic \transpose c ais { \music }
  \transpose c deses { \music }
  \naturalizeMusic \transpose c deses { \music }
}



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% end ly snippet
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