Re: Chord Diagram markup

[Jan Nieuwenhuizen]

Carl D. Sorensen writes:

> 1.  (*) text/plain          ( ) text/html           

[please omit html stuff next time]

> I have developed a very rudimentary chord diagram markup, thanks to the
> def-markup-command created by Nicolas Sceaux.

Great!

> ("scripts-open").  But when I tried it, I got nothing -- no output and
> no errors.  Any suggestions?

>My code is still in the file, but
> commented out.

Try this:
      
#(define (draw-strings stringcount fretcount th size)
  (let ((sl (* (+ fretcount 1) size))
        (halfthick (* th 0.5)))
    (if (= stringcount 1)
        (ly:make-stencil (list 'draw-line th 0 0 0 sl)
                         (cons (- halfthick) halfthick)
                         (cons (- halfthick) (+ sl halfthick)))
        (ly:stencil-combine-at-edge
         (draw-strings (- stringcount 1) fretcount th size) 0 1
         (ly:make-stencil
          (list 'draw-line th 0 0 0 sl)
          (cons (- halfthick) halfthick) 
          (cons (- halfthick) (+ sl halfthick)))
         (- size th) 0))))

#(define (draw-frets fretcount stringcount th size)
  (let ((fretlength (* (- stringcount 1) size))
        (halfthick (* th 0.5)))
     (if (= fretcount 0)
         (ly:make-stencil (list 'draw-line th 0 size fretlength size)
                          (cons 0 fretlength)
                          (cons (- size halfthick) (+  size halfthick)))
         (ly:stencil-combine-at-edge
          (draw-frets (- fretcount 1) stringcount th size) 1 1
          (ly:make-stencil (list 'draw-line th 0 0 fretlength 0)
                           (cons 0 fretlength)
                           (cons (- halfthick) (+ halfthick)))
          (- size th) 0))))
                         
#(define (draw-dots stringcount fretcount size dotlist)
  "Make dots for fret diagram."
  (let ((dotrad (* size 0.25))
        (xpos (* (- stringcount (caar dotlist)) size))
        (ypos (* (+ 1.5 (- fretcount (cdar dotlist))) size))
        (extent (cons (- (*  size 0.25)) (*  size 0.25))))
    (if (null? (cdr dotlist))
        (ly:make-stencil (list 'dot xpos ypos dotrad ) extent extent)
        (ly:stencil-add
         (draw-dots stringcount fretcount size (cdr dotlist))
         (ly:make-stencil (list 'dot xpos ypos dotrad) extent
                          extent)))))
 
#(define (draw-xo stringcount fretcount size font xolist)
"Put x and o on chord diagram."
    (let ((dotrad (* size 0.25))
          (mypair (car xolist))
          (restlist (cdr xolist))
          (glyphname (if (char=? (cdar xolist) #\x) "accidentals-4"
                         "scripts-open"))
          (tmpdot (if (char=? (cdar xolist) #\x) 0 (* size 0.25)))
          (xpos (* (- stringcount (caar xolist)) size))
          (ypos (* (+ 1.5 fretcount) size))
          (extent (cons (- (* size 0.25)) (* size 0.25))))

      ;; FIXME, what exacly do you want here?
      (if (null? restlist)
          (ly:find-glyph-by-name font glyphname)
          (ly:stencil-add
           (ly:find-glyph-by-name font glyphname)
           ;;(ly:make-stencil (list 'dot xpos ypos tmpdot) extent extent)
           (ly:stencil-add
            (draw-xo stringcount fretcount size font (cdr xolist))
            (ly:make-stencil (list 'dot xpos ypos tmpdot) extent extent))))))
  
#(define (char->num char)
  (- (char->integer char) (char->integer #\0)))

#(define (string-xo string chord-list)
  "convert ordered list of frets and xo's into list of (string (x
or o)) pairs"
  
  (if (null? chord-list)
      (list)
      (let ((fret (car chord-list)) (rest (cdr chord-list)))
        (if (char-numeric? fret)
            (string-xo (- string 1) rest)
            (list* (cons string fret) 
                   (string-xo (- string 1) rest))))))

#(define (string-dot string chord-list)
  "convert ordered list of frets into list of (string fret) pairs"
  
  (if (null? chord-list)
      (list )
      (let ((fret (car chord-list)) (rest (cdr chord-list)))
        (if (or (char=? fret #\x) (char=? fret #\o))
            (string-dot (- string 1) rest)
            (list* (cons string (char->num fret)) 
               (string-dot (- string 1) rest))))))

#(define (xo-list chord-string stringcount)
  "Convert a chord string into an xo-list"
  (string-xo stringcount (string->list chord-string)))
      
#(define (dot-list chord-string stringcount)
  "Convert a chord string into a dot-list"
  (string-dot stringcount (string->list chord-string)))
       
#(define (make-chord-diagram chord-string stringcount fretcount
                             th size font)
  "Make a chord diagram"
  (ly:stencil-add 
   (draw-strings stringcount fretcount th size)
   (draw-frets fretcount stringcount th size)
   (draw-dots stringcount fretcount size
               (dot-list chord-string stringcount))
   (draw-xo stringcount fretcount size font
            (xo-list chord-string stringcount))))
 
#(def-markup-command (chord-diagram paper props size defstring)
  (number? string?)
  "Syntax: \\chord-diagram size defstring
   eg: \\markup-fret-diagram #0.75 #\\"xxo232\\"
    for fret spacing 3/4 of staff space, D chord diagram"
   (let ((font (ly:paper-get-font paper '(((font-family . music))))))
     (format (current-error-port) "FONT: ~S\n" font)
     (make-chord-diagram defstring 6 4 .05 size font)))

\score {
    \notes {
        a'2.^\markup \chord-diagram #1 #"x33211"
        c'' ^\markup \chord-diagram #0.5 #"o221oo"
        c' ^\markup \chord-diagram #0.75 #"xxo232"
    }
  \paper{ raggedright = ##t }
}


-- 
Jan Nieuwenhuizen <address@hidden> | GNU LilyPond - The music typesetter
http://www.xs4all.nl/~jantien       | http://www.lilypond.org