--- /dev/null
+;;;; harp-pedals.scm --
+;;;;
+;;;; source file of the GNU LilyPond music typesetter
+;;;;
+;;;; (c) 2008 Reinhold Kainhofer <reinhold@kainhofer.com>
+
+
+;;;; More verbose version, which takes a list of directions. It's commented
+;;;; out, because it has some issues (see below) and does not add any new
+;;;; functionality over \harp-pedal
+;; (define-builtin-markup-command (harp-pedal-verbose layout props pedal-list) (list?)
+;; music ; markup type
+;; ((size 1.0)
+;; (harp-pedal-details)
+;; (thickness 0.5))
+;; "Make a harp pedal diagram containing the directions indicated in @var{pedal-list}.
+;;
+;; For example,
+;;
+;; @example
+;; \\markup \\pedal-diagram-verbose #'(1 0 -1 #\\| 0 0 1 1)
+;; \\markup \\pedal-diagram-verbose #(list UP CENTER DOWN #\\| CENTER CENTER UP UP)
+;; @end example
+;; "
+;; (make-harp-pedal layout props pedal-list))
+
+
+(define-builtin-markup-command (harp-pedal layout props definition-string) (string?)
+ music ; markup type for the documentation!
+ ((size 1.0)
+ (harp-pedal-details)
+ (thickness 0.5))
+ "Make a harp pedal diagram.
+
+Possible elements in @var{definition-string}:
+
+@table @code
+@item ^
+pedal is up
+@item -
+pedal is neutral
+@item v
+pedal is down
+@item |
+vertical divider line
+@item o
+the following pedal should be circled (indicating a change)
+@end table
+
+The function also checks if the string has the typical form of three
+pedals, then the divider and then the remaining four pedals. If not it
+prints out a warning. However, in any case, it will also print each symbol
+in the order as given. This means you can place the divider (even multiple
+dividers) anywhere you want, but you'll have to live with the warnings.
+
+The appearance of the diagram can be tweaked inter alia using the size property
+of the TextScript grob (@code{\\override Voice.TextScript #'size = #0.3}) for
+the overall, the thickness property
+(@code{\\override Voice.TextScript #'thickness = #3}) for the line thickness of
+the horizontal line and the divider. The remaining configuration (box sizes,
+offsets and spaces) is done by the harp-pedal-details list of properties
+(@code{\\override Voice.TextScript #'harp-pedal-details #'box-width = #1}).
+It contains the following settings: @code{box-offset} (vertical shift of the
+box center for up/down pedals), @code{box-width}, @code{box-height},
+@code{space-before-divider} (the spacing between two boxes before the
+divider) and @code{space-after-divider} (box spacing after the divider).
+
+@lilypond[verbatim,quote]
+\\markup \\harp-pedal #\"^-v|--ov^\"
+@end lilypond
+"
+
+;; There is also a \harp-pedal-verbose version, which
+;; takes a list of -1/0/1 directions and a possible |. Unfortunately, it has some
+;; caveats:
+;; 1) the | cannot be given as a string "|" but as a character #\| and
+;; the "o" has to be given as #\o.
+;; 2) if one wants to use directions like UP, CENTER or DOWN, one cannot use
+;; '(UP DOWN CENTER #\| ....), because the contents of that list are
+;; never evaluated to -1/0/1. Instead one has to explicitly create a
+;; list like (list UP DOWN CENTER #\| ....)
+
+ (make-harp-pedal layout props (harp-pedals-parse-string definition-string)))
+
+
+(define (harp-pedals-parse-string definition-string)
+ "Parse a harp pedals diagram string and return a list containing 1, 0, -1, #\\o or #\\|"
+ (map (lambda (c)
+ (case c
+ ((#\^) 1)
+ ((#\v) -1)
+ ((#\-) 0)
+ ((#\| #\o) c)
+ (else c)))
+ (string->list definition-string)))
+
+(define (harp-pedal-info pedal-list)
+ (let check ((pedals pedal-list)
+ (pedalcount 0)
+ (dividerpositions '()))
+ (if (null? pedals)
+ (cons pedalcount (reverse dividerpositions))
+
+ (case (car pedals)
+ ((-1 0 1) (check (cdr pedals) (+ pedalcount 1) dividerpositions))
+ ((#\|) (check (cdr pedals) pedalcount (cons pedalcount dividerpositions)))
+ (else (check (cdr pedals) pedalcount dividerpositions))))))
+
+(define (harp-pedal-check pedal-list)
+ "Perform some sanity checks for harp pedals (7 pedals, divider after third)"
+ (let ((info (harp-pedal-info pedal-list)))
+ ; 7 pedals:
+ (if (not (equal? (car info) 7))
+ (ly:warning "Harp pedal diagram contains ~a pedals rather than the usual 7." (car info)))
+ ; One divider after third pedal:
+ (if (null? (cdr info))
+ (ly:warning "Harp pedal diagram does not contain a divider (usually after third pedal).")
+ (if (not (equal? (cdr info) '(3)))
+ (ly:warning "Harp pedal diagram contains dividers at positions ~a. Normally, there is only one divider after the third pedal." (cdr info))))))
+
+
+(define (make-harp-pedal layout props pedal-list)
+ "Make a harp pedals diagram markup"
+
+
+ ; FIXME the size variable should be defined by a prop. lookup
+ (harp-pedal-check pedal-list)
+
+ (let* ((size (chain-assoc-get 'size props 1.2))
+ (details (chain-assoc-get 'harp-pedal-details props '()))
+ (dy (* size (assoc-get 'box-offset details 0.8))) ; offset of the box center from the line
+ (line-width (* (ly:output-def-lookup layout 'line-thickness)
+ (chain-assoc-get 'thickness props 0.5)))
+ (box-width (* size (assoc-get 'box-width details 0.4)))
+ (box-hheight (* size (/ (assoc-get 'box-height details 1.0) 2))) ; half the box-height, saves some divisions by 2
+ (spacebeforedivider (* size (assoc-get 'space-before-divider details 0.8))) ; full space between boxes before the first divider
+ (spaceafterdivider (* size (assoc-get 'space-after-divider details 0.8))) ; full space between boxes
+ ;(spacebeforedivider (/ (+ box-width (* 8 spaceafterdivider)) 8))
+ (box-x-dimensions (lambda (prev-x p space) (cons (+ prev-x space)
+ (+ prev-x space box-width))))
+ (box-y-dimensions (lambda (prev-x p space) (cons (- (* p dy) box-hheight)
+ (+ (* p dy) box-hheight))))
+ (divider-stencil (lambda (xpos) (make-line-stencil line-width xpos (- 0 dy box-hheight) xpos (+ dy box-hheight))))
+ (result (let process-pedal ((remaining pedal-list)
+ (prev-x 0)
+ (stencils '())
+ (circled #f)
+ (space spacebeforedivider))
+ ; Terminal condition of the recursion, return (final-x . stencil-list)
+ (if (null? remaining)
+ (cons (+ prev-x space) stencils)
+
+ (case (car remaining)
+ ((1 0 -1) ; Pedal up/neutral/down
+ (let* ((p (car remaining))
+ (stencil (make-filled-box-stencil
+ (box-x-dimensions prev-x p space)
+ (box-y-dimensions prev-x p space)))
+ ;(circle-stencil (if circled (rounded-box-stencil stencil 0.05 0.3 0.1 ) stencil))
+ (circle-stencil (if circled (circle-stencil stencil 0.05 0.2 ) stencil))
+ (new-prev-x (+ prev-x space box-width)))
+ (process-pedal (cdr remaining) new-prev-x (cons circle-stencil stencils) #f space)))
+ ((#\|) ; Divider line
+ (let* ((xpos (+ prev-x space))
+ (stencil (divider-stencil xpos))
+ (new-prev-x (+ prev-x space)))
+ (process-pedal (cdr remaining) new-prev-x (cons stencil stencils) circled spaceafterdivider)))
+ ((#\o) ; Next pedal should be circled
+ (process-pedal (cdr remaining) prev-x stencils #t space))
+ (else
+ (ly:warning "Unhandled entry in harp-pedal: ~a" (car remaining))
+ (process-pedal (cdr remaining) prev-x stencils circled space))))))
+ (final-x (car result))
+ (stencils (reverse (cdr result))))
+ ; Add the horizontal line and combine all stencils:
+ (apply ly:stencil-add
+ (cons
+ (make-line-stencil line-width 0 0 final-x 0)
+ stencils))))
+