+ articulations)
+ finger-found))
+
+ (define (string-number event)
+ "Get the string-number from @var{event}. Return @var{#f}
+if no string-number is present."
+ (let ((num (ly:event-property event 'string-number)))
+ (if (number? num)
+ num
+ #f)))
+
+ (define (delete-free-string string)
+ (if (number? string)
+ (set! free-strings
+ (delete string free-strings))))
+
+ (define (close-enough fret)
+ "Decide if @var{fret} is acceptable, given the already used frets."
+ (if (null? specified-frets)
+ #t
+ (reduce
+ (lambda (x y)
+ (and x y))
+ #t
+ (map (lambda (specced-fret)
+ (or (eq? 0 specced-fret)
+ (and (not restrain-open-strings)
+ (eq? 0 fret))
+ (>= maximum-stretch (abs (- fret specced-fret)))))
+ specified-frets))))
+
+ (define (string-qualifies string pitch)
+ "Can @var{pitch} be played on @var{string}, given already placed
+notes?"
+ (let* ((fret (calc-fret pitch string tuning)))
+ (and (or (and (not restrain-open-strings)
+ (eq? fret 0))
+ (>= fret minimum-fret))
+ (integer? fret)
+ (close-enough fret))))
+
+ (define (open-string string pitch)
+ "Is @var{pitch} and open-string note on @var{string}, given
+the current tuning?"
+ (let* ((fret (calc-fret pitch string tuning)))
+ (eq? fret 0)))
+
+ (define (set-fret! pitch-entry string finger)
+ (let ((this-fret (calc-fret (car pitch-entry)
+ string
+ tuning)))
+ (if (< this-fret 0)
+ (ly:warning (_ "Negative fret for pitch ~a on string ~a")
+ (car pitch-entry) string)
+ (if (not (integer? this-fret))
+ (ly:warning (_ "Missing fret for pitch ~a on string ~a")
+ (car pitch-entry) string)))
+ (delete-free-string string)
+ (set! specified-frets (cons this-fret specified-frets))
+ (list-set! string-fret-fingers
+ (cdr pitch-entry)
+ (list string this-fret finger))))
+
+ (define (kill-note! string-fret-fingers note-index)
+ (list-set! string-fret-fingers note-index (list #f #t)))
+
+ (define string-fret-fingers
+ (map (lambda (string finger)
+ (if (null? finger)
+ (list string #f)
+ (list string #f finger)))
+ defined-strings defined-fingers))
+
+ ;;; body of determine-frets-and-strings
+ (let* ((pitch-alist (apply (lambda (mylist)
+ (let ((index -1))
+ (map (lambda (note)
+ (begin
+ (set! index (1+ index))
+ (cons (note-pitch note)
+ index)))
+ mylist)))
+ notes '()))
+ (pitches (map note-pitch notes)))
+
+ ;; handle notes with strings assigned and fingering of 0
+ (for-each
+ (lambda (pitch-entry string-fret-finger)
+ (let* ((string (list-ref string-fret-finger 0))
+ (finger (if (eq? (length string-fret-finger) 3)
+ (list-ref string-fret-finger 2)
+ '()))
+ (pitch (car pitch-entry))
+ (digit (if (null? finger)
+ #f
+ finger)))
+ (if (or (not (null? string))
+ (eq? digit 0))
+ (if (eq? digit 0)
+ ;; here we handle fingers of 0 -- open strings
+ (let ((fit-string
+ (find (lambda (string)
+ (open-string string pitch))
+ free-strings)))
+ (if fit-string
+ (set-fret! pitch-entry fit-string #f)
+ (ly:warning (_ "No open string for pitch ~a")
+ pitch)))
+ ;; here we handle assigned strings
+ (let ((this-fret
+ (calc-fret pitch string tuning))
+ (handle-negative
+ (ly:context-property context
+ 'handleNegativeFrets
+ 'recalculate)))
+ (cond ((or (and (>= this-fret 0) (integer? this-fret))
+ (eq? handle-negative 'include))
+ (set-fret! pitch-entry string finger))
+ ((eq? handle-negative 'recalculate)
+ (begin
+ (ly:warning
+ (_ "Requested string for pitch requires negative fret: string ~a pitch ~a")
+ string
+ pitch)
+ (ly:warning (_ "Ignoring string request and recalculating."))
+ (list-set! string-fret-fingers
+ (cdr pitch-entry)
+ (if (null? finger)
+ (list '() #f)
+ (list '() #f finger)))))
+ ((eq? handle-negative 'ignore)
+ (begin
+ (ly:warning
+ (_ "Requested string for pitch requires negative fret: string ~a pitch ~a")
+ string
+ pitch)
+ (ly:warning (_ "Ignoring note in tablature."))
+ (kill-note! string-fret-fingers
+ (cdr pitch-entry))))))))))
+ pitch-alist string-fret-fingers)
+ ;; handle notes without strings assigned -- sorted by pitch, so
+ ;; we need to use the alist to have the note number available
+ (for-each
+ (lambda (pitch-entry)
+ (let* ((string-fret-finger (list-ref string-fret-fingers
+ (cdr pitch-entry)))
+ (string (list-ref string-fret-finger 0))
+ (finger (if (eq? (length string-fret-finger) 3)
+ (list-ref string-fret-finger 2)
+ '()))
+ (pitch (car pitch-entry))
+ (fit-string
+ (find (lambda (string)
+ (string-qualifies string pitch))
+ free-strings)))
+ (if (not (list-ref string-fret-finger 1))
+ (if fit-string
+ (set-fret! pitch-entry fit-string finger)
+ (begin
+ (ly:warning (_ "No string for pitch ~a (given frets ~a)")
+ pitch
+ specified-frets)
+ (kill-note! string-fret-fingers
+ (cdr pitch-entry)))))))
+ (sort pitch-alist (lambda (pitch-entry-a pitch-entry-b)
+ (ly:pitch<? (car pitch-entry-b)
+ (car pitch-entry-a)))))
+ string-fret-fingers)) ;; end of determine-frets-and-strings
+
+ (define (get-predefined-fretboard predefined-fret-table tuning pitches)
+ "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. Returns a placement-list."
+
+ (define (get-fretboard key)
+ (let ((hash-handle
+ (hash-get-handle predefined-fret-table key)))
+ (if hash-handle
+ (cdr hash-handle) ; return table entry
+ '())))
+
+ ;; body of get-predefined-fretboard
+ (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 of determine-frets
+ (let* ((predefined-fret-table
+ (ly:context-property context 'predefinedDiagramTable))
+ (tunings (ly:context-property context 'stringTunings))
+ (string-count (length tunings))
+ (grob (if (null? rest) '() (car rest)))
+ (pitches (map (lambda (x) (ly:event-property x 'pitch)) notes))
+ (defined-strings (map (lambda (x)
+ (if (null? x)
+ x
+ (ly:event-property x 'string-number)))
+ (car specified-info)))
+ (defined-fingers (map (lambda (x)
+ (if (null? x)
+ x
+ (ly:event-property x 'digit)))
+ (cadr specified-info)))
+ (default-strings (ly:context-property context 'defaultStrings '()))
+ (strings-used (if (and (zero? (entry-count defined-strings))
+ (not (zero? (entry-count default-strings))))
+ default-strings
+ defined-strings))
+ (predefined-fretboard
+ (if predefined-fret-table
+ (get-predefined-fretboard
+ predefined-fret-table
+ tunings
+ pitches)
+ '())))
+ (if (null? predefined-fretboard)
+ (let ((string-frets
+ (determine-frets-and-strings
+ notes
+ strings-used
+ defined-fingers
+ (ly:context-property context 'minimumFret 0)
+ (ly:context-property context 'maximumFretStretch 4)
+ tunings)))
+ (if (null? grob)
+ string-frets
+ (create-fretboard
+ context grob (string-frets->placement-list
+ (filter (lambda (entry)
+ (car entry))
+ string-frets)
+ string-count))))
+ (if (null? grob)
+ (placement-list->string-frets predefined-fretboard)
+ (create-fretboard context grob predefined-fretboard)))))
+
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; tablature
+
+;; The TabNoteHead tablatureFormat callbacks.
+
+;; Calculate the fret from pitch and string number as letter
+;; The fret letter is taken from 'fretLabels if present
+(define-public (fret-letter-tablature-format
+ context string-number fret-number)
+ (let ((labels (ly:context-property context 'fretLabels)))
+ (make-vcenter-markup
+ (cond
+ ((= 0 (length labels))
+ (string (integer->char (+ fret-number (char->integer #\a)))))
+ ((and (<= 0 fret-number) (< fret-number (length labels)))
+ (list-ref labels fret-number))
+ (else
+ (ly:warning (_ "No label for fret ~a (on string ~a);
+only ~a fret labels provided")
+ fret-number string-number (length labels))
+ ".")))))
+
+;; Display the fret number as a number
+(define-public (fret-number-tablature-format
+ context string-number fret-number)
+ (make-vcenter-markup
+ (format #f "~a" fret-number)))
+
+;; 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
+ context string-number fret-number)
+ (make-vcenter-markup
+ (number->string (cond
+ ((and (> fret-number 0) (= string-number 5))
+ (+ fret-number 5))
+ (else fret-number)))))
+
+;; Tab note head staff position functions
+;;
+;; Define where in the staff to display a given string. Some forms of
+;; tablature put the tab note heads in the spaces, rather than on the
+;; lines
+
+(define-public (tablature-position-on-lines context string-number)
+ (let* ((string-tunings (ly:context-property context 'stringTunings))
+ (string-count (length string-tunings))
+ (string-one-topmost (ly:context-property context 'stringOneTopmost))
+ (staff-line (- (* 2 string-number) string-count 1)))
+ (if string-one-topmost
+ (- staff-line)
+ staff-line)))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; bar numbers
+
+(define-public ((every-nth-bar-number-visible n) barnum mp)
+ (= 0 (modulo barnum n)))
+
+(define-public ((modulo-bar-number-visible n m) barnum mp)
+ (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 mp)
+ (> barnum 1))
+
+(define-public (first-bar-number-invisible-save-broken-bars barnum mp)
+ (or (> barnum 1)
+ (> (ly:moment-main-numerator mp) 0)))
+
+(define-public (first-bar-number-invisible-and-no-parenthesized-bar-numbers barnum mp)
+ (and (> barnum 1)
+ (= (ly:moment-main-numerator mp) 0)))
+
+(define-public (robust-bar-number-function barnum measure-pos alt-number context)
+ (define (get-number-and-power an pow)
+ (if (<= an alt-number)
+ (get-number-and-power (+ an (expt 26 (1+ pow))) (1+ pow))
+ (cons (+ alt-number (- (expt 26 pow) an)) (1- pow))))
+ (define (make-letter so-far an pow)
+ (if (< pow 0)
+ so-far
+ (let ((pos (modulo (quotient an (expt 26 pow)) 26)))
+ (make-letter (string-append so-far
+ (substring "abcdefghijklmnopqrstuvwxyz"
+ pos
+ (1+ pos)))
+ an
+ (1- pow)))))
+ (let* ((number-and-power (get-number-and-power 0 0))
+ (begin-measure (= 0 (ly:moment-main-numerator measure-pos)))
+ (maybe-open-parenthesis (if begin-measure "" "("))
+ (maybe-close-parenthesis (if begin-measure "" ")")))
+ (markup (string-append maybe-open-parenthesis
+ (number->string barnum)
+ (make-letter ""
+ (car number-and-power)
+ (cdr number-and-power))
+ maybe-close-parenthesis))))
+
+(define-public (all-bar-numbers-visible barnum mp) #t)
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; percent repeat counters
+
+(define-public ((every-nth-repeat-count-visible n) count context)
+ (= 0 (modulo count n)))
+
+(define-public (all-repeat-counts-visible count context) #t)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; make-engraver helper macro
+
+(defmacro-public make-engraver forms
+ "Helper macro for creating Scheme engravers.
+
+The usual form for an engraver is an association list (or alist)
+mapping symbols to either anonymous functions or to another such
+alist.
+
+@code{make-engraver} accepts forms where the first element is either
+an argument list starting with the respective symbol, followed by the
+function body (comparable to the way @code{define} is used for
+defining functions), or a single symbol followed by subordinate forms
+in the same manner. You can also just make an alist pair
+literally (the @samp{car} is quoted automatically) as long as the
+unevaluated @samp{cdr} is not a pair. This is useful if you already
+have defined your engraver functions separately.
+
+Symbols mapping to a function would be @code{initialize},
+@code{start-translation-timestep}, @code{process-music},
+@code{process-acknowledged}, @code{stop-translation-timestep}, and
+@code{finalize}. Symbols mapping to another alist specified in the
+same manner are @code{listeners} with the subordinate symbols being
+event classes, and @code{acknowledgers} and @code{end-acknowledgers}
+with the subordinate symbols being interfaces."
+ (let loop ((forms forms))
+ (if (cheap-list? forms)
+ `(list
+ ,@(map (lambda (form)
+ (if (pair? (car form))
+ `(cons ',(caar form) (lambda ,(cdar form) ,@(cdr form)))
+ `(cons ',(car form) ,(loop (cdr form)))))
+ forms))
+ forms)))