+ empty-markup)))
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; fret diagrams
+
+(define-public (determine-frets context grob notes string-numbers)
+
+ (define (ensure-number a b)
+ (if (number? a)
+ a
+ b))
+
+ (define (string-frets->dot-placement string-frets string-count)
+ (let* ((desc (list->vector
+ (map (lambda (x) (list 'mute (1+ x)))
+ (iota string-count)))))
+
+ (for-each (lambda (sf)
+ (let* ((string (car sf))
+ (fret (cadr sf))
+ (finger (caddr sf)))
+
+ (vector-set!
+ desc (1- string)
+ (if (= 0 fret)
+ (list 'open string)
+ (if finger
+ (list 'place-fret string fret finger)
+ (list 'place-fret string fret))))))
+ string-frets)
+
+ (vector->list desc)))
+
+ (define (get-predefined-fretboard predefined-fret-table tuning pitches)
+; (_i "Search through @var{predefined-fret-table} looking for a predefined
+;fretboard with a key of @var{(tuning . pitches)}. The search will check
+;both up and down an octave in order to accomodate transposition of the
+;chords.")
+ (define (get-fretboard key)
+ (let ((hash-handle
+ (hash-get-handle predefined-fret-table key)))
+ (if hash-handle
+ (cdr hash-handle) ; return table entry
+ '())))
+
+ (let ((test-fretboard (get-fretboard (cons tuning pitches))))
+ (if (not (null? test-fretboard))
+ test-fretboard
+ (let ((test-fretboard
+ (get-fretboard
+ (cons tuning (map (lambda (x) (shift-octave x 1)) pitches)))))
+ (if (not (null? test-fretboard))
+ test-fretboard
+ (get-fretboard
+ (cons tuning (map (lambda (x) (shift-octave x -1))
+ pitches))))))))
+
+;; body.
+ (let* ((tunings (ly:context-property context 'stringTunings))
+ (my-string-count (length tunings))
+ (details (ly:grob-property grob 'fret-diagram-details))
+ (predefined-frets
+ (ly:context-property context 'predefinedDiagramTable))
+ (pitches (map (lambda (x) (ly:event-property x 'pitch)) notes))
+ (predefined-fretboard
+ (if predefined-frets
+ (get-predefined-fretboard
+ predefined-frets
+ tunings
+ pitches)
+ '())))
+
+ (set! (ly:grob-property grob 'fret-diagram-details)
+ (if (null? details)
+ (acons 'string-count my-string-count '())
+ (acons 'string-count my-string-count details)))
+
+ (set! (ly:grob-property grob 'dot-placement-list)
+ (if (not (null? predefined-fretboard))
+ predefined-fretboard
+ (let* ((minimum-fret
+ (ensure-number
+ (ly:context-property context 'minimumFret)
+ 0))
+ (max-stretch
+ (ensure-number
+ (ly:context-property context 'maximumFretStretch)
+ 4))
+ (string-frets
+ (determine-frets-mf
+ notes
+ string-numbers
+ minimum-fret
+ max-stretch
+ tunings)))
+ (string-frets->dot-placement
+ string-frets
+ my-string-count))))))
+
+(define-public (determine-frets-mf notes string-numbers
+ minimum-fret max-stretch
+ tunings)
+
+ (define (calc-fret pitch string tuning)
+ (- (ly:pitch-semitones pitch) (list-ref tuning (1- string))))
+
+ (define (note-pitch a)
+ (ly:event-property a 'pitch))
+
+ (define (note-pitch>? a b)
+ (ly:pitch<? (note-pitch b)
+ (note-pitch a)))
+
+ (define (note-finger ev)
+ (let* ((articulations (ly:event-property ev 'articulations))
+ (finger-found #f))
+
+ (map (lambda (art)
+ (let* ((num (ly:event-property art 'digit)))
+
+ (if (and (eq? 'fingering-event (ly:event-property art 'class))
+ (number? num))
+ (set! finger-found num))))
+ articulations)
+
+ finger-found))
+
+ (define (note-string ev)
+ (let* ((articulations (ly:event-property ev 'articulations))
+ (string-found #f))
+
+ (map (lambda (art)
+ (let* ((num (ly:event-property art 'string-number)))
+
+ (if (number? num)
+ (set! string-found num))))
+ articulations)
+
+ string-found))
+
+ (define (del-string string)
+ (if (number? string)
+ (set! free-strings
+ (delete string free-strings))))
+
+ (define specified-frets '())
+ (define free-strings '())
+
+ (define (close-enough fret)
+ (reduce
+ (lambda (x y)
+ (and x y))
+ #t
+ (map (lambda (specced-fret)
+ (> max-stretch (abs (- fret specced-fret))))
+ specified-frets)))
+
+ (define (string-qualifies string pitch)
+ (let* ((fret (calc-fret pitch string tunings)))
+ (and (>= fret minimum-fret)
+ (close-enough fret))))
+
+ (define string-fret-fingering-tuples '())
+ (define (set-fret note string)
+ (set! string-fret-fingering-tuples
+ (cons (list string
+ (calc-fret (ly:event-property note 'pitch)
+ string tunings)
+ (note-finger note))
+ string-fret-fingering-tuples))
+ (del-string string))
+
+
+ ;;; body.
+ (set! specified-frets
+ (filter identity (map
+ (lambda (note)
+ (if (note-string note)
+ (calc-fret (note-pitch note)
+ (note-string note) tunings)
+ #f))
+ notes)))
+
+ (set! free-strings (map 1+ (iota (length tunings))))
+
+ (for-each (lambda (note)
+ (del-string (note-string note)))
+ notes)
+
+
+ (for-each
+ (lambda (note)
+ (if (note-string note)
+ (set-fret note (note-string note))
+ (let* ((fit-string (find (lambda (string)
+ (string-qualifies string (note-pitch note)))
+ free-strings)))
+ (if fit-string
+ (set-fret note fit-string)
+ (ly:warning "No string for pitch ~a (given frets ~a)"
+ (note-pitch note)
+ specified-frets)))))
+ (sort notes note-pitch>?))
+
+ string-fret-fingering-tuples)
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; tablature
+
+;; The TabNoteHead tablatureFormat callback.
+;; Compute the text grob-property
+(define-public (fret-number-tablature-format string context event)
+ (let* ((tuning (ly:context-property context 'stringTunings))
+ (pitch (ly:event-property event 'pitch)))
+
+ (make-whiteout-markup
+ (make-vcenter-markup
+ (format
+ "~a"
+ (- (ly:pitch-semitones pitch)
+ (list-ref tuning
+ ;; remove 1 because list index starts at 0
+ ;;and guitar string at 1.
+ (1- string))))))))
+
+;; The 5-string banjo has got a extra string, the fifth (duh), which
+;; starts at the fifth fret on the neck. Frets on the fifth string
+;; are referred to relative to the other frets:
+;; the "first fret" on the fifth string is really the sixth fret
+;; on the banjo neck.
+;; We solve this by defining a new fret-number-tablature function:
+(define-public (fret-number-tablature-format-banjo string context event)
+ (let* ((tuning (ly:context-property context 'stringTunings))
+ (pitch (ly:event-property event 'pitch)))
+
+ (make-whiteout-markup
+ (make-vcenter-markup
+ (let ((fret (- (ly:pitch-semitones pitch) (list-ref tuning (1- string)))))
+ (number->string (cond
+ ((and (> fret 0) (= string 5))
+ (+ fret 5))
+ (else fret))))))))
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; bar numbers
+
+(define-public ((every-nth-bar-number-visible n) barnum)
+ (= 0 (modulo barnum n)))
+
+(define-public ((modulo-bar-number-visible n m) barnum)
+ (and (> barnum 1) (= m (modulo barnum n))))
+
+(define-public ((set-bar-number-visibility n) tr)
+ (let ((bn (ly:context-property tr 'currentBarNumber)))
+ (ly:context-set-property! tr 'barNumberVisibility
+ (modulo-bar-number-visible n (modulo bn n)))))
+
+(define-public (first-bar-number-invisible barnum) (> barnum 1))
+
+(define-public (all-bar-numbers-visible barnum) #t)
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; percent repeat counters