-;;;; fret-diagrams.scm -- \r
-;;;;\r
-;;;; source file of the GNU LilyPond music typesetter\r
-;;;; \r
-;;;; (c) 2004 Carl D. Sorensen <c_sorensen@byu.edu>\r
-\r
-\r
-(define (fret-parse-marking-list marking-list fret-count)\r
- (let* ((fret-range (list 1 fret-count))\r
- (barre-list '())\r
- (dot-list '())\r
- (xo-list '())\r
- (output-alist '()))\r
- (let parse-item ((mylist marking-list))\r
- (if (not (null? mylist))\r
- (let* ((my-item (car mylist)) (my-code (car my-item)))\r
- (cond\r
- ((or (eq? my-code 'open)(eq? my-code 'mute))\r
- (set! xo-list (cons* my-item xo-list)))\r
- ((eq? my-code 'barre)\r
- (set! barre-list (cons* (cdr my-item) barre-list)))\r
- ((eq? my-code 'place-fret)\r
- (set! dot-list (cons* (cdr my-item) dot-list))))\r
- (parse-item (cdr mylist)))))\r
- ; calculate fret-range\r
- (let ((maxfret 0) (minfret 99))\r
- (let updatemax ((fret-list dot-list))\r
- (if (null? fret-list)\r
- '()\r
- (let ((fretval (second (car fret-list))))\r
- (if (> fretval maxfret) (set! maxfret fretval))\r
- (if (< fretval minfret) (set! minfret fretval))\r
- (updatemax (cdr fret-list)))))\r
- (if (> maxfret fret-count)\r
- (set! fret-range (list minfret\r
- (let ((upfret (- (+ minfret fret-count) 1)))\r
- (if (> maxfret upfret) maxfret upfret)))))\r
- ; subtract fret from dots\r
- (set! dot-list (subtract-base-fret (- (car fret-range) 1) dot-list)))\r
-; (display "barre-list ") (display barre-list) (display "\n")\r
- (acons 'fret-range fret-range\r
- (acons 'barre-list barre-list\r
- (acons 'dot-list dot-list\r
- (acons 'xo-list xo-list '()))))))\r
- \r
-(define (subtract-base-fret base-fret dot-list)\r
-"Subtract @var{base-fret} from every fret in @var{dot-list}" \r
- (if (null? dot-list)\r
- '()\r
- (let ((this-list (car dot-list)))\r
- (cons* (list (car this-list) (- (second this-list) base-fret) (if (null? (cddr this-list))\r
- '()\r
- (third this-list)))\r
- (subtract-base-fret base-fret (cdr dot-list))))))\r
-\r
-(define (draw-strings string-count fret-range th size)\r
-"Draw the strings (vertical lines) for a fret diagram with @var{string-count} strings and frets as indicated\r
- in @var{fret-range}. Line thickness is given by @var{th}, fret & string spacing by @var{size}. "\r
- (let* ((fret-count (+ (- (cadr fret-range) (car fret-range)) 1))\r
- (sl (* (+ fret-count 1) size))\r
- (sth (* size th))\r
- (half-thickness (* sth 0.5))\r
- (gap (- size sth))\r
- (string-stencil (ly:make-stencil (list 'draw-line sth 0 0 0 sl)\r
- (cons (- half-thickness) half-thickness)\r
- (cons (- half-thickness) (+ sl half-thickness)))))\r
- (if (= string-count 1)\r
- string-stencil\r
- (ly:stencil-combine-at-edge\r
- (draw-strings (- string-count 1) fret-range th size) X RIGHT\r
- string-stencil\r
- gap 0))))\r
-\r
-(define (draw-fret-lines fret-count string-count th size)\r
- "Draw @var{fret-count} frets (horizontal lines) for a fret diagram with @var{string-count} strings.\r
- Line thickness is given by @var{th}, fret & string spacing by @var{size}. "\r
- (let* ((fret-length (* (- string-count 1) size))\r
- (sth (* size th))\r
- (half-thickness (* sth 0.5))\r
- (gap (- size sth))\r
- (fret-line (ly:make-stencil (list 'draw-line sth half-thickness size (- fret-length half-thickness) size)\r
- (cons 0 fret-length)\r
- (cons (- size half-thickness) (+ size half-thickness)))))\r
- (if (= fret-count 1)\r
- fret-line\r
- (ly:stencil-combine-at-edge fret-line Y UP\r
- (draw-fret-lines (- fret-count 1) string-count th size)\r
- gap 0))))\r
- \r
-(define (draw-thick-top-fret props string-count th size)\r
- "Draw a thick top fret for a fret diagram whose base fret is not 1."\r
- (let* ((sth (* th size))\r
- (top-fret-thick (* sth (chain-assoc-get 'top-fret-thickness props 3.0)))\r
- (top-half-thick (* top-fret-thick 0.5))\r
- (half-thick (* sth 0.5))\r
- (x1 half-thick)\r
- (x2 (+ half-thick (* size (- string-count 1))))\r
- (y1 0)\r
- (y2 top-fret-thick)\r
- (x-extent (cons (- x1) x2))\r
- (y-extent (cons 0 y2)))\r
- (ly:make-stencil (list 'round-filled-box x1 x2 y1 y2 th)\r
- x-extent y-extent))) \r
- \r
- \r
-(define (draw-frets paper props fret-range string-count th size)\r
- "Draw the frets (horizontal lines) for a fret diagram with @var{string-count} strings and frets as indicated\r
- in @var{fret-range}. Line thickness is given by @var{th}, fret & string spacing by @var{size}. "\r
- (let* ((top-fret-thick (* th (chain-assoc-get 'top-fret-thickness props 3.0)))\r
- (fret-count (+ (- (cadr fret-range) (car fret-range)) 1))\r
- (fret-length (* (- string-count 1) size))\r
- (half-thickness (* th 0.5))\r
- (base-fret (car fret-range)))\r
- (ly:stencil-combine-at-edge\r
- (draw-fret-lines fret-count string-count th size) Y UP\r
- (if (= base-fret 1)\r
- (draw-thick-top-fret props string-count th size)\r
- (draw-fret-lines 1 string-count th size)) \r
- (- size th) 0))) \r
- \r
-(define (get-center-shift extent)\r
-"Return the amount of shift required to make @var{extent} be centered"\r
- (let ((minval (car extent))\r
- (maxval (cdr extent)))\r
- (/ (- minval maxval) 2)))\r
-\r
-\r
-;; ly:stencil-get-extent is missing from 2.2 on\r
-;(define (centered-text-stencil font text)\r
-;"Create a centered text stencil of @var{text} in font @var{font}"\r
-;(let* ((text-stencil (fontify-text font text))\r
-; (x-shift (get-center-shift (ly:stencil-get-extent text-stencil X)))\r
-; (y-shift (get-center-shift y-extent (ly:stencil-get-extent text-stencil Y))))\r
-; (ly:stencil-translate-axis \r
-; (ly:stencil-translate-axis text-stencil x-shift X)\r
-; y-shift Y))) \r
-\r
-(define (draw-dots paper props string-count fret-range size dot-position dot-list)\r
- "Make dots for fret diagram."\r
-; (display "In draw-dots" dot-list)\r
- (let* ((finger-code (chain-assoc-get 'finger-code props 'none))\r
- (dot-radius (* size (chain-assoc-get 'dot-radius props 0.25)))\r
- (finger-xoffset (chain-assoc-get 'finger-xoffset props -0.25))\r
- (finger-yoffset (chain-assoc-get 'finger-yoffset props (- size)))\r
- (label-font-name (chain-assoc-get 'label-font-name props "cmss8"))\r
- (dot-label-font-mag (* size (chain-assoc-get 'dot-label-font-mag props .45)))\r
- (dot-circle-font-mag (* size (chain-assoc-get 'dot-circle-font-mag props .75)))\r
- (string-label-font-mag (* size (chain-assoc-get 'string-label-font-mag props 0.6)))\r
- (fret-count (+ (- (cadr fret-range) (car fret-range) 1)))\r
- (mypair (car dot-list))\r
- (restlist (cdr dot-list))\r
- (xpos (* size (- string-count (car mypair))))\r
-;TODO -- figure out what 4 is and get rid of it\r
-;UGH -- 4?\r
- (ypos (* size (+ 4 (- fret-count (cadr mypair) dot-position ))))\r
- (finger (caddr mypair))\r
- (finger (if (number? finger) (number->string finger) finger))\r
- (string-label-font (ly:paper-get-font paper `(((font-magnification . ,string-label-font-mag)\r
- (font-name . ,label-font-name)))))\r
- (dot-label-font (ly:paper-get-font paper `(((font-magnification . ,dot-label-font-mag)\r
- (font-name . ,label-font-name)))))\r
- (dot-circle-font (ly:paper-get-font paper `(((font-magnification . ,dot-circle-font-mag)\r
- (font-name . ,label-font-name)))))\r
- (extent (cons (- dot-radius) dot-radius))\r
- (dotstencil (if (or (eq? finger '())(eq? finger-code 'none))\r
- (ly:make-stencil (list 'dot xpos ypos dot-radius ) extent extent)\r
- (if (eq? finger-code 'white-circled)\r
-; TODO -- Get nice circled numbers in the font, instead of this kludge\r
-; UGH -- Constants in here need to go\r
-; Note: for finger (this stencil) xpos should be related only to font size, ypos should be related to both font size and dot-position\r
-; These are not yet worked out, and should be. But perhaps I'd like first to get a nice font for circled numbers / letters \r
- (ly:stencil-add \r
- (ly:stencil-translate-axis \r
- (ly:stencil-translate-axis \r
- (fontify-text dot-label-font finger) (- xpos (* size 0.2)) X)\r
- (- ypos (* 1 dot-radius size)) Y)\r
-; These lines are a better way to do it, but they require ly:stencil-get-extent, which is missing from 2.2.0\r
-; (centered-text-stencil dot-label-font finger) xpos X)\r
-; ypos Y)\r
- ;UGH -- Constants in xpos and ypos need to go. xpos should be related to font mag,\r
- ; ypos should be related to both font magnification and dot-position. Again, I may want to wait for the nice font with\r
- ; convenient zero point (right at the center of the dot). \r
- ;TODO -- Alternatively, perhaps I should query for the extent of the glyph,\r
- ; and place it accordingly. That actually sounds better\r
- (ly:stencil-translate-axis\r
- (ly:stencil-translate-axis \r
- (fontify-text dot-circle-font "O") (- xpos (* 0.6 dot-circle-font-mag)) X)\r
- (- ypos (* 0.5 dot-circle-font-mag)) Y))\r
-; These lines are a better way to do it, but they require ly:stencil-get-exten, which is missing from 2.2.0\r
-; (centered-text-stencil dot-circle-font "O") xpos X)\r
-; ypos Y))\r
- (if (eq? finger-code 'below-string) \r
- (ly:stencil-add \r
- (ly:make-stencil (list 'dot xpos ypos dot-radius ) extent extent)\r
- (ly:stencil-translate-axis \r
- (ly:stencil-translate-axis \r
- (fontify-text string-label-font finger) (+ xpos (* size finger-xoffset)) X)\r
- (* size finger-yoffset) Y)))))))\r
- (if (null? restlist)\r
- dotstencil\r
- (ly:stencil-add (draw-dots paper props string-count fret-range size dot-position restlist)\r
- dotstencil))))\r
-\r
-(define (draw-xo paper props string-count fret-range size xo-list) \r
-"Put open and mute string indications on diagram, as contained in @var{xo-list}."\r
- (let* ((fret-count (+ (- (cadr fret-range) (car fret-range) 1)))\r
- (xo-font-mag (* size (chain-assoc-get 'xo-font-magnification props 0.5)))\r
- (xo-font-name (chain-assoc-get 'xo-font-name props "cmss8"))\r
- (xo-horizontal-offset (* size (chain-assoc-get 'xo-horizontal-offset props -0.35)))\r
- (font (ly:paper-get-font paper `(((font-magnification . ,xo-font-mag)\r
- (font-name . ,xo-font-name)))))\r
- (mypair (car xo-list))\r
- (restlist (cdr xo-list))\r
- (glyph-string (if (eq? (car mypair) 'mute) "X" "O"))\r
- (xpos (+ (* (- string-count (cadr mypair)) size) xo-horizontal-offset ))\r
- (glyph-stencil (ly:stencil-translate-axis (fontify-text font glyph-string) xpos X)))\r
- (if (null? restlist)\r
- glyph-stencil\r
- (ly:stencil-add\r
- (draw-xo paper props string-count fret-range size restlist)\r
- glyph-stencil))))\r
-\r
-(define (make-bezier-sandwich-list left right bottom height thickness)\r
-" Make the argument list for a horizontal bezier sandwich from @var{left} to @var{right} with a bottom at @var{bottom}, \r
- a height of @var{height}, and a thickness of @var{thickness}."\r
- (let* ((width (+ (- right left) 1))\r
- (x1 (+ (* width thickness) left))\r
- (x2 (- right (* width thickness)))\r
- (bottom-control-point-height (+ bottom (- height thickness)))\r
- (top-control-point-height (+ bottom height)))\r
- ; order of points is: left cp low, right cp low, right end low, left end low\r
- ; right cp high, left cp high, left end high, right end high.\r
- (list (cons x1 bottom-control-point-height) (cons x2 bottom-control-point-height) (cons right bottom) (cons left bottom)\r
- (cons x2 top-control-point-height) (cons x1 top-control-point-height) (cons left bottom) (cons right bottom))))\r
-\r
-(define (draw-barre paper props string-count fret-range size dot-position barre-list)\r
- "Create barre indications for a fret diagram"\r
- (if (not (null? barre-list))\r
- (let* ((string1 (caar barre-list))\r
- (string2 (cadar barre-list))\r
- (fret (caddar barre-list))\r
- ; 2 is 1 for empty fret at bottom of figure + 1 for interval (top-fret - fret + 1) -- not an arbitrary constant\r
- (bottom (* size (- (+ 2 (- (cadr fret-range) fret)) dot-position)))\r
- (left (* size (- string-count string1)))\r
- (right (* size (- string-count string2)))\r
- (bezier-thick (chain-assoc-get 'bezier-thickness props 0.1))\r
- (bezier-height (chain-assoc-get 'bezier-height props 0.5))\r
- (bezier-list (make-bezier-sandwich-list left right bottom (* size bezier-height) (* size bezier-thick)))\r
- (sandwich-stencil (ly:make-stencil (list 'bezier-sandwich `(quote ,bezier-list) (* size bezier-thick) )\r
- (cons 0 right)\r
- (cons 0 (+ bottom (* size bezier-height))))))\r
- (if (not (null? (cdr barre-list)))\r
- (ly:stencil-add sandwich-stencil\r
- (draw-barre paper props string-count fret-range size dot-position (cdr barre-list)))\r
- sandwich-stencil ))))\r
- \r
-(define (label-fret paper props string-count fret-range size)\r
- "Label the base fret on a fret diagram"\r
- (let* ((base-fret (car fret-range))\r
- (label-font-mag (chain-assoc-get 'fret-label-font-magnification props 0.8))\r
- (label-horizontal-offset (chain-assoc-get 'fret-label-horizontal-offset props -0.5))\r
- (label-vertical-offset (chain-assoc-get 'fret-label-vertical-offset props -0.2))\r
- (fret-count (+ (- (cadr fret-range) (car fret-range)) 1))\r
- (font (ly:paper-get-font paper `(((font-magnification . ,(* label-font-mag size))(font-name . "cmss8")\r
- (font-encoding Tex-text))))))\r
- (ly:stencil-translate-axis \r
- (ly:stencil-translate-axis (fontify-text font (if (> base-fret 1)\r
- (format #f "~(~:@r~)" base-fret)\r
- " ")) (* size (+ string-count label-horizontal-offset)) X)\r
- (* size (+ fret-count label-vertical-offset)) Y)))\r
- \r
-(def-markup-command (fret-diagram-verbose paper props marking-list)\r
- (list?)\r
- "Make a fret diagram containing the symbols indicated in @var{marking-list}\r
- Syntax: \\fret-diagram marking-list\r
- For example,\r
- @verbatim\r
- \\markup \\fret-diagram #\'((mute 6) (mute 5) (open 4) (place-fret 3 2) (place-fret 2 3) (place-fret 1 2))\r
- @end verbatim \r
- will produce a standard D chord diagram without fingering indications.\r
- Possible elements in @var{marking-list}:\r
- (mute string-number) -- place a small 'x' at the top of string @var{string-number}\r
- (open string-number) -- place a small 'o' at the top of string @var{string-number}\r
- (barre start-string end-string fret-number) -- place a barre indicator (much like a tie) from string @var{start-string}\r
- to string @var{end-string} at fret @var{fret-number}\r
- (place-fret string-number fret-number finger-value) -- place a fret playing indication\r
- on string @var{string-number} at fret @var{fret-number} with an optional fingering label @var{finger-value}\r
- By default, the fret playing indicator is a solid dot. If the @var{finger} part of the place-fret element is present,\r
- @var{finger-value} will be displayed according to the setting of the variable @var{finger-code}\r
- There is no limit to the number of fret indications per string."\r
- (make-fret-diagram paper props marking-list))\r
- \r
-(define (make-fret-diagram paper props marking-list)\r
-" Make a fret diagram markup" \r
- (let* (\r
- ; note: here we get items from props that are needed in this routine, or that are needed in more than one\r
- ; of the procedures called from this routine. If they're only used in one of the sub-procedure, they're \r
- ; obtained in that procedure\r
- \r
- (size (chain-assoc-get 'size props 1.0)) ; needed for everything\r
-;TODO -- get string-count directly from length of stringTunings; requires FretDiagram engraver, which is not yet available\r
- (string-count (chain-assoc-get 'string-count props 6)) ; needed for everything\r
- (fret-count (chain-assoc-get 'fret-count props 4)) ; needed for everything\r
- (dot-position (chain-assoc-get 'dot-position props 0.6)) ; needed for both draw-dots and draw-barre\r
- (th (* (ly:paper-lookup paper 'linethickness)\r
- (chain-assoc-get 'thickness props 0.5))) ; needed for both draw-frets and draw-strings\r
- \r
- (alignment (chain-assoc-get 'alignment props -0.4)) ; needed only here\r
- (xo-padding (* th (chain-assoc-get 'xo-padding props 2))) ; needed only here\r
-\r
- (parameters (fret-parse-marking-list marking-list fret-count))\r
- (dot-list (cdr (assoc 'dot-list parameters)))\r
- (xo-list (cdr (assoc 'xo-list parameters)))\r
- (fret-range (cdr (assoc 'fret-range parameters)))\r
- (barre-list (cdr (assoc 'barre-list parameters)))\r
- (fret-diagram-stencil (ly:stencil-add\r
- (draw-strings string-count fret-range th size)\r
- (draw-frets paper props fret-range string-count th size))))\r
- (if (not (null? dot-list))\r
- (set! fret-diagram-stencil (ly:stencil-add\r
- (draw-dots paper props string-count fret-range size dot-position dot-list)\r
- fret-diagram-stencil)))\r
- (if (not (null? xo-list))\r
- (set! fret-diagram-stencil (ly:stencil-combine-at-edge\r
- fret-diagram-stencil Y UP\r
- (draw-xo paper props string-count fret-range size xo-list) xo-padding 0)))\r
- (if (not (null? barre-list))\r
- (set! fret-diagram-stencil (ly:stencil-add\r
- (draw-barre paper props string-count fret-range size dot-position barre-list)\r
- fret-diagram-stencil)))\r
- (set! fret-diagram-stencil (ly:stencil-add fret-diagram-stencil (label-fret paper props string-count fret-range size)))\r
- (ly:stencil-align-to! fret-diagram-stencil X alignment)\r
- fret-diagram-stencil))\r
- \r
-(def-markup-command (fret-diagram paper props size definition-string)\r
- (number? string?)\r
- "Syntax: \\fret-diagram size definition-string\r
- eg: \\markup \\fret-diagram #0.75 #\"6-x;5-x;4-o;3-2;2-3;1-2;\"\r
- for fret spacing 3/4 of staff space, D chord diagram\r
- Syntax rules for @var{definition-string}:\r
- Diagram items are separated by semicolons.\r
- Possible items:\r
- t:number -- set the line thickness (in staff spaces). Default 0.05\r
- h:number -- set the height of the diagram in frets. Default 4\r
- w:number -- set the width of the diagram in strings. Default 6\r
- f:number -- set fingering label type \r
- (0 = none, 1 = in circle on string, 2 = below string) Default 0\r
- d:number -- set radius of dot, in terms of fret spacing. Default 0.25\r
- p:number -- set the position of the dot in the fret space. 0.5 is centered; 1 is on lower fret bar,\r
- 0 is on upper fret bar. Default 0.6 \r
- c:string1-string2-fret -- include a barre mark from string1 to string2 on fret\r
- string-fret -- place a dot on string at fret. If fret is o, string is identified\r
- as open. If fret is x, string is identified as muted.\r
- string-fret-fingering -- place a dot on string at fret, and label with fingering as \r
- defined by f: code.\r
- Note: There is no limit to the number of fret indications per string."\r
- (set! props (acons 'size size props))\r
- (let ((definition-list (parse-definition-string props definition-string)))\r
- (make-fret-diagram paper (car definition-list) (cdr definition-list))))\r
-\r
-(define (parse-definition-string props definition-string)\r
- "parse a fret diagram string and return a pair containing:\r
- props, modified as necessary by the definition-string\r
- a fret-indication list with the appropriate values"\r
- (let* ((fret-count 4)\r
- (string-count 6)\r
- (thickness 0.05)\r
- (finger-code 0)\r
- (dot-size 0.25)\r
- (dot-position 0.6)\r
- (fret-range (list 1 fret-count))\r
- (barre-list '())\r
- (dot-list '())\r
- (xo-list '())\r
- (output-list '())\r
- (items (string-split definition-string #\;)))\r
- (let parse-item ((myitems items))\r
- (if (not (null? (cdr myitems))) \r
- (let ((test-string (car myitems)))\r
- (case (car (string->list (substring test-string 0 1))) \r
- ((#\f) (let* ((finger-code (get-numeric-from-key test-string))\r
- (finger-id (case finger-code\r
- ((0) 'none)\r
- ((1) 'white-circled) \r
- ((2) 'below-string))))\r
- (set! props\r
- (acons 'finger-code finger-id props))))\r
- ((#\t) (let ((thickness (get-numeric-from-key test-string)))\r
- (set! props (acons 'thickness thickness props))))\r
- ((#\c) (set! output-list (cons-fret (cons 'barre (numerify (string-split (substring test-string 2) #\-)))\r
- output-list)))\r
- ((#\h) (let ((fret-count (get-numeric-from-key test-string)))\r
- (set! props (acons 'fret-count fret-count props))))\r
- ((#\w) (let ((string-count (get-numeric-from-key test-string)))\r
- (set! props (acons 'string-count string-count props))))\r
- ((#\d) (let ((dot-size (get-numeric-from-key test-string)))\r
- (set! props (acons 'dot-radius dot-size props))))\r
- ((#\p) (let ((dot-position (get-numeric-from-key test-string)))\r
- (set! props (acons 'dot-position dot-position props))))\r
- (else \r
- (let ((this-list (string-split test-string #\-)))\r
- (if (string->number (cadr this-list))\r
- (set! output-list (cons-fret (cons 'place-fret (numerify this-list)) output-list))\r
- (if (equal? (cadr this-list) "x" )\r
- (set! output-list (cons-fret (list 'mute (string->number (car this-list))) output-list))\r
- (set! output-list (cons-fret (list 'open (string->number (car this-list))) output-list)))))))\r
- (parse-item (cdr myitems)))))\r
- `((,props) . ,output-list)))\r
-\r
-(define (cons-fret new-value old-list)\r
-" Put together a fret-list in the format desired by parse-string "\r
- (if (eq? old-list '())\r
- (list new-value)\r
- (cons* new-value old-list)))\r
- \r
-(define (get-numeric-from-key keystring)\r
- "Get the numeric value from a key of the form k:val"\r
- (string->number (substring keystring 2 (string-length keystring) )))\r
- \r
-(define (numerify mylist)\r
- "Convert string values to numeric or character"\r
- (if (null? mylist)\r
- '()\r
- (let ((numeric-value (string->number (car mylist))))\r
- (if numeric-value\r
- (cons* numeric-value (numerify (cdr mylist)))\r
- (cons* (car (string->list (car mylist))) (numerify (cdr mylist)))))))\r
- \r
+;;;; fret-diagrams.scm --
+;;;;
+;;;; source file of the GNU LilyPond music typesetter
+;;;;
+;;;; (c) 2004--2006 Carl D. Sorensen <c_sorensen@byu.edu>
+
+(define (fret-parse-marking-list marking-list fret-count)
+ (let* ((fret-range (list 1 fret-count))
+ (barre-list '())
+ (dot-list '())
+ (xo-list '())
+ (output-alist '()))
+ (let parse-item ((mylist marking-list))
+ (if (not (null? mylist))
+ (let* ((my-item (car mylist)) (my-code (car my-item)))
+ (cond
+ ((or (eq? my-code 'open)(eq? my-code 'mute))
+ (set! xo-list (cons* my-item xo-list)))
+ ((eq? my-code 'barre)
+ (set! barre-list (cons* (cdr my-item) barre-list)))
+ ((eq? my-code 'place-fret)
+ (set! dot-list (cons* (cdr my-item) dot-list))))
+ (parse-item (cdr mylist)))))
+ ; calculate fret-range
+ (let ((maxfret 0) (minfret 99))
+ (let updatemax ((fret-list dot-list))
+ (if (null? fret-list)
+ '()
+ (let ((fretval (second (car fret-list))))
+ (if (> fretval maxfret) (set! maxfret fretval))
+ (if (< fretval minfret) (set! minfret fretval))
+ (updatemax (cdr fret-list)))))
+ (if (> maxfret fret-count)
+ (set! fret-range (list minfret
+ (let ((upfret (- (+ minfret fret-count) 1)))
+ (if (> maxfret upfret) maxfret upfret)))))
+ ; subtract fret from dots
+ (set! dot-list (subtract-base-fret (- (car fret-range) 1) dot-list)))
+ (acons 'fret-range fret-range
+ (acons 'barre-list barre-list
+ (acons 'dot-list dot-list
+ (acons 'xo-list xo-list '()))))))
+
+(define (subtract-base-fret base-fret dot-list)
+"Subtract @var{base-fret} from every fret in @var{dot-list}"
+ (if (null? dot-list)
+ '()
+ (let ((this-list (car dot-list)))
+ (cons* (list (car this-list) (- (second this-list) base-fret) (if (null? (cddr this-list))
+ '()
+ (third this-list)))
+ (subtract-base-fret base-fret (cdr dot-list))))))
+
+(define (sans-serif-stencil layout props mag text)
+"create a stencil in sans-serif font based on @var{layout} and @var{props}
+with magnification @varr{mag} of the string @var{text}."
+ (let* ((my-props (prepend-alist-chain 'font-size (stepmag mag)
+ (prepend-alist-chain 'font-family 'sans props))))
+ (interpret-markup layout my-props text)))
+
+
+(define (draw-strings string-count fret-range th size)
+"Draw the strings (vertical lines) for a fret diagram with
+@var{string-count} strings and frets as indicated in @var{fret-range}.
+Line thickness is given by @var{th}, fret & string spacing by
+@var{size}. "
+ (let* ((fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
+ (sl (* (+ fret-count 1) size))
+ (sth (* size th))
+ (half-thickness (* sth 0.5))
+ (gap (- size sth))
+ (string-stencil (ly:make-stencil (list 'draw-line sth 0 0 0 sl)
+ (cons (- half-thickness) half-thickness)
+ (cons (- half-thickness) (+ sl half-thickness)))))
+ (if (= string-count 1)
+ string-stencil
+ (ly:stencil-combine-at-edge
+ (draw-strings (- string-count 1) fret-range th size) X RIGHT
+ string-stencil
+ gap 0))))
+
+(define (draw-fret-lines fret-count string-count th size)
+ "Draw @var{fret-count} frets (horizontal lines) for a fret diagram
+with @var{string-count} strings. Line thickness is given by @var{th},
+fret & string spacing by @var{size}. "
+ (let* ((fret-length (* (- string-count 1) size))
+ (sth (* size th))
+ (half-thickness (* sth 0.5))
+ (gap (- size sth))
+ (fret-line (ly:make-stencil (list 'draw-line sth half-thickness size (- fret-length half-thickness) size)
+ (cons 0 fret-length)
+ (cons (- size half-thickness) (+ size half-thickness)))))
+ (if (= fret-count 1)
+ fret-line
+ (ly:stencil-combine-at-edge fret-line Y UP
+ (draw-fret-lines (- fret-count 1) string-count th size)
+ gap 0))))
+
+(define (draw-thick-top-fret props string-count th size)
+ "Draw a thick top fret for a fret diagram whose base fret is not 1."
+ (let* ((sth (* th size))
+; (top-fret-thick (* sth (chain-assoc-get 'top-fret-thickness props 3.0)))
+ (top-fret-thick (* sth 3.0))
+; (top-half-thick (* top-fret-thick 0.5))
+ (half-thick (* sth 0.5))
+ (x1 half-thick)
+ (x2 (+ half-thick (* size (- string-count 1))))
+ (y1 (- half-thick))
+ (y2 (+ top-fret-thick half-thick))
+ (x-extent (cons (- x1) x2))
+ (y-extent (cons 0 y2)))
+ (ly:make-stencil (list 'round-filled-box x1 x2 y1 y2 sth)
+ x-extent y-extent)))
+
+
+(define (draw-frets layout props fret-range string-count th size)
+ "Draw the frets (horizontal lines) for a fret diagram with
+@var{string-count} strings and frets as indicated in @var{fret-range}.
+Line thickness is given by @var{th}, fret & string spacing by
+@var{size}. "
+ (let* ((fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
+ (fret-length (* (- string-count 1) size))
+ (half-thickness (* th 0.5))
+ (base-fret (car fret-range)))
+ (ly:stencil-combine-at-edge
+ (draw-fret-lines fret-count string-count th size) Y UP
+ (if (= base-fret 1)
+ (draw-thick-top-fret props string-count th size)
+ (draw-fret-lines 1 string-count th size))
+ (- size th) 0)))
+
+
+(define (draw-dots layout props string-count fret-range size finger-code
+ dot-position dot-radius dot-thickness dot-list)
+ "Make dots for fret diagram."
+ (let* ((scale-dot-radius (* size dot-radius))
+ (scale-dot-thick (* size dot-thickness))
+ (dot-color (chain-assoc-get 'dot-color props 'black))
+; (finger-xoffset (chain-assoc-get 'finger-xoffset props -0.25))
+; (finger-yoffset (chain-assoc-get 'finger-yoffset props (- size)))
+ (finger-xoffset -0.25)
+ (finger-yoffset (- (* size 0.5)))
+; (dot-label-font-mag (* scale-dot-radius (chain-assoc-get 'dot-label-font-mag props 1.0)))
+ (dot-label-font-mag scale-dot-radius)
+; (string-label-font-mag (* size (chain-assoc-get 'label-font-mag props 0.7)))
+ (string-label-font-mag (* size 0.6))
+ (fret-count (+ (- (cadr fret-range) (car fret-range) 1)))
+ (mypair (car dot-list))
+ (restlist (cdr dot-list))
+ (xpos (* size (- string-count (car mypair))))
+;TODO -- figure out what 4 is and get rid of it
+;UGH -- 4?
+ (ypos (* size (+ 4 (- fret-count (cadr mypair) dot-position ))))
+ (extent (cons (- scale-dot-radius) scale-dot-radius))
+ (finger (caddr mypair))
+ (finger (if (number? finger) (number->string finger) finger))
+ (dotstencil (if (eq? dot-color 'white)
+ (ly:stencil-add
+ (make-circle-stencil scale-dot-radius scale-dot-thick #t)
+ (ly:stencil-in-color
+ (make-circle-stencil
+ (- scale-dot-radius (* 0.5 scale-dot-thick)) 0 #t)
+ 1 1 1))
+ (make-circle-stencil scale-dot-radius scale-dot-thick #t)))
+ (positioned-dot (begin
+ ;(display dotstencil)
+ (ly:stencil-translate-axis
+ (ly:stencil-translate-axis dotstencil xpos X)
+ ypos Y)))
+
+ (labeled-dot-stencil
+ (if (or (eq? finger '())(eq? finger-code 'none))
+ positioned-dot
+ (if (eq? finger-code 'in-dot)
+ (let* ((finger-label (centered-stencil
+ (sans-serif-stencil layout props
+ dot-label-font-mag finger))))
+ (ly:stencil-translate-axis
+ (ly:stencil-translate-axis
+ (ly:stencil-add
+ dotstencil
+ (if (eq? dot-color 'white)
+ finger-label
+ (ly:stencil-in-color finger-label 1 1 1)))
+ xpos X)
+ ypos Y))
+ (if (eq? finger-code 'below-string)
+ (ly:stencil-add
+ positioned-dot
+ (ly:stencil-translate-axis
+ (ly:stencil-translate-axis
+ (centered-stencil (sans-serif-stencil layout props
+ string-label-font-mag finger))
+ xpos X)
+ (* size finger-yoffset) Y))
+ ;unknown finger-code
+ positioned-dot)))))
+ (if (null? restlist)
+ labeled-dot-stencil
+ (ly:stencil-add
+ (draw-dots layout props string-count fret-range size finger-code
+ dot-position dot-radius dot-thickness restlist)
+ labeled-dot-stencil))))
+
+(define (draw-xo layout props string-count fret-range size xo-list)
+"Put open and mute string indications on diagram, as contained in @var{xo-list}."
+ (let* ((fret-count (+ (- (cadr fret-range) (car fret-range) 1)))
+; (xo-font-mag (* size (chain-assoc-get 'xo-font-magnification props 0.5)))
+ (xo-font-mag (* size 0.5))
+; (xo-horizontal-offset (* size (chain-assoc-get 'xo-horizontal-offset props -0.35)))
+ (xo-horizontal-offset (* size -0.35))
+ (mypair (car xo-list))
+ (restlist (cdr xo-list))
+ (glyph-string (if (eq? (car mypair) 'mute) "X" "O"))
+ (xpos (+ (* (- string-count (cadr mypair)) size) xo-horizontal-offset ))
+ (glyph-stencil (ly:stencil-translate-axis
+ (sans-serif-stencil layout props (* size xo-font-mag) glyph-string) xpos X)))
+ (if (null? restlist)
+ glyph-stencil
+ (ly:stencil-add
+ (draw-xo layout props string-count fret-range size restlist)
+ glyph-stencil))))
+
+(define (make-bezier-sandwich-list left right bottom height thickness)
+" Make the argument list for a horizontal bezier sandwich from
+@var{left} to @var{right} with a bottom at @var{bottom}, a height of
+@var{height}, and a thickness of @var{thickness}."
+ (let* ((width (+ (- right left) 1))
+ (x1 (+ (* width thickness) left))
+ (x2 (- right (* width thickness)))
+ (bottom-control-point-height (+ bottom (- height thickness)))
+ (top-control-point-height (+ bottom height)))
+ ; order of points is: left cp low, right cp low, right end low, left end low
+ ; right cp high, left cp high, left end high, right end high.
+ (list (cons x1 bottom-control-point-height) (cons x2 bottom-control-point-height) (cons right bottom) (cons left bottom)
+ (cons x2 top-control-point-height) (cons x1 top-control-point-height) (cons left bottom) (cons right bottom))))
+
+(define (draw-barre layout props string-count fret-range size finger-code dot-position dot-radius barre-list)
+ "Create barre indications for a fret diagram"
+ (if (not (null? barre-list))
+ (let* ((string1 (caar barre-list))
+ (string2 (cadar barre-list))
+ (fret (caddar barre-list))
+ (barre-type (chain-assoc-get 'barre-type props 'curved))
+ (scale-dot-radius (* size dot-radius))
+ (barre-vertical-offset (chain-assoc-get 'barre-vertical-offset props 0.5))
+ ;; 2 is 1 for empty fret at bottom of figure + 1 for interval (top-fret - fret + 1) -- not an arbitrary constant
+ (dot-center-y (* size
+ (- (+ 2 (- (cadr fret-range) fret)) dot-position)))
+ (bottom (+ dot-center-y (* barre-vertical-offset scale-dot-radius)))
+ (left (* size (- string-count string1)))
+ (right (* size (- string-count string2)))
+;; (bezier-thick (chain-assoc-get 'bezier-thickness props 0.1))
+ (bezier-thick 0.1)
+;; (bezier-height (chain-assoc-get 'bezier-height props 0.5))
+ (bezier-height 0.5)
+ (bezier-list (make-bezier-sandwich-list left right bottom (* size bezier-height) (* size bezier-thick)))
+ (barre-stencil (if (eq? barre-type 'straight)
+ (ly:make-stencil (list 'draw-line (* size dot-radius) left dot-center-y right dot-center-y)
+ (cons left right)
+ (cons (- dot-center-y scale-dot-radius) (+ dot-center-y scale-dot-radius)))
+ (ly:make-stencil (list 'bezier-sandwich `(quote ,bezier-list) (* size bezier-thick))
+ (cons left right)
+ (cons bottom (+ bottom (* size bezier-height)))))))
+ (if (not (null? (cdr barre-list)))
+ (ly:stencil-add barre-stencil
+ (draw-barre layout props string-count fret-range size finger-code
+ dot-position dot-radius (cdr barre-list)))
+ barre-stencil ))))
+
+(define (stepmag mag)
+"Calculate the font step necessary to get a desired magnification"
+(* 6 (/ (log mag) (log 2))))
+
+(define (label-fret layout props string-count fret-range size)
+ "Label the base fret on a fret diagram"
+ (let* ((base-fret (car fret-range))
+; (label-font-mag (chain-assoc-get 'label-font-mag props 0.7))
+ (label-font-mag 0.5)
+; (label-vertical-offset (chain-assoc-get 'fret-label-vertical-offset props -0.2))
+ (label-vertical-offset -0.2)
+ (number-type (chain-assoc-get 'number-type props 'roman-lower))
+ (fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
+ (label-text
+ (cond
+ ((equal? number-type 'roman-lower) (format #f "~(~:@r~)" base-fret))
+ ((equal? number-type 'roman-upper) (format #f "~:@r" base-fret))
+ ((equal? 'arabic number-type) (format #f "~d" base-fret))
+ (else (format #f "~(~:@r~)" base-fret)))))
+ (ly:stencil-translate-axis
+ (sans-serif-stencil layout props (* size label-font-mag) label-text)
+ (* size (+ fret-count label-vertical-offset)) Y)))
+
+(def-markup-command (fret-diagram-verbose layout props marking-list)
+ (list?)
+ "Make a fret diagram containing the symbols indicated in @var{marking-list}
+
+ For example,
+
+@example
+ \\markup \\fret-diagram #'((mute 6) (mute 5) (open 4)
+ (place-fret 3 2) (place-fret 2 3) (place-fret 1 2))
+@end example
+
+ will produce a standard D chord diagram without fingering indications.
+
+Possible elements in @var{marking-list}:
+@table @asis
+@item (mute string-number)
+Place a small 'x' at the top of string @var{string-number}
+
+@item (open string-number)
+Place a small 'o' at the top of string @var{string-number}
+
+@item (barre start-string end-string fret-number)
+Place a barre indicator (much like a tie) from string @var{start-string}to string @var{end-string} at fret @var{fret-number}
+
+@item (place-fret string-number fret-number finger-value)
+
+Place a fret playing indication on string @var{string-number} at fret
+@var{fret-number} with an optional fingering label @var{finger-value}.
+By default, the fret playing indicator is a solid dot. This can be
+changed by setting the value of the variable @var{dot-color}. If the
+@var{finger} part of the place-fret element is present,
+@var{finger-value} will be displayed according to the setting of the
+variable @var{finger-code}. There is no limit to the number of fret
+indications per string.
+
+@end table
+"
+ (make-fret-diagram layout props marking-list))
+
+(define (make-fret-diagram layout props marking-list)
+" Make a fret diagram markup"
+ (let* (
+ ; note: here we get items from props that are needed in this routine, or that are needed in more than one
+ ; of the procedures called from this routine. If they're only used in one of the sub-procedure, they're
+ ; obtained in that procedure
+
+ (size (chain-assoc-get 'size props 1.0)) ; needed for everything
+;TODO -- get string-count directly from length of stringTunings; requires FretDiagram engraver, which is not yet available
+;TODO -- adjust padding for fret label? it appears to be too close to dots
+ (string-count (chain-assoc-get 'string-count props 6)) ; needed for everything
+ (fret-count (chain-assoc-get 'fret-count props 4)) ; needed for everything
+ (finger-code (chain-assoc-get 'finger-code props 'none)) ; needed for both draw-dots and draw-barre
+ (default-dot-radius (if (eq? finger-code 'in-dot) 0.425 0.25)) ; bigger dots if labeled
+ (default-dot-position (if (eq? finger-code 'in-dot) (- 0.95 default-dot-radius) 0.6)) ; move up to make room for bigger if labeled
+ (dot-radius (chain-assoc-get 'dot-radius props default-dot-radius)) ; needed for both draw-dots and draw-barre
+ (dot-position (chain-assoc-get 'dot-position props default-dot-position)) ; needed for both draw-dots and draw-barre
+ (th (* (ly:output-def-lookup layout 'line-thickness)
+ (chain-assoc-get 'thickness props 0.5))) ; needed for both draw-frets and draw-strings
+
+ (alignment (chain-assoc-get 'align-dir props -0.4)) ; needed only here
+; (xo-padding (* th (chain-assoc-get 'padding props 2))) ; needed only here
+ (label-space (* 0.25 size))
+ (xo-padding (* th size 5))
+ (label-dir (chain-assoc-get 'label-dir props RIGHT))
+ (parameters (fret-parse-marking-list marking-list fret-count))
+ (dot-list (cdr (assoc 'dot-list parameters)))
+ (xo-list (cdr (assoc 'xo-list parameters)))
+ (fret-range (cdr (assoc 'fret-range parameters)))
+ (barre-list (cdr (assoc 'barre-list parameters)))
+ (fret-diagram-stencil (ly:stencil-add
+ (draw-strings string-count fret-range th size)
+ (draw-frets layout props fret-range string-count th size))))
+ (if (not (null? barre-list))
+ (set! fret-diagram-stencil (ly:stencil-add
+ (draw-barre layout props string-count fret-range size finger-code
+ dot-position dot-radius barre-list)
+ fret-diagram-stencil)))
+ (if (not (null? dot-list))
+ (set! fret-diagram-stencil (ly:stencil-add
+ fret-diagram-stencil
+ (draw-dots layout props string-count fret-range size finger-code
+ dot-position dot-radius th dot-list))))
+ (if (not (null? xo-list))
+ (set! fret-diagram-stencil (ly:stencil-combine-at-edge
+ fret-diagram-stencil Y UP
+ (draw-xo layout props string-count fret-range size xo-list) xo-padding 0)))
+ (if (> (car fret-range) 1)
+ (set! fret-diagram-stencil
+ (ly:stencil-combine-at-edge fret-diagram-stencil X label-dir
+ (label-fret layout props string-count fret-range size) label-space 0)))
+ (ly:stencil-aligned-to fret-diagram-stencil X alignment)
+ ))
+
+(def-markup-command (fret-diagram layout props definition-string)
+ (string?)
+ "
+Example
+
+@example
+ \\markup \\fret-diagram #\"s:0.75;6-x;5-x;4-o;3-2;2-3;1-2;\"
+@end example
+
+for fret spacing 3/4 of staff space, D chord diagram
+
+Syntax rules for @var{definition-string}:
+@itemize @minus
+
+@item
+Diagram items are separated by semicolons.
+
+@item
+Possible items:
+
+@itemize @bullet
+@item
+s:number -- set the fret spacing of the diagram (in staff spaces). Default 1
+
+@item
+t:number -- set the line thickness (in staff spaces). Default 0.05
+
+@item
+h:number -- set the height of the diagram in frets. Default 4
+
+@item
+w:number -- set the width of the diagram in strings. Default 6
+
+@item
+f:number -- set fingering label type (0 = none, 1 = in circle on string, 2 = below string) Default 0
+
+@item
+d:number -- set radius of dot, in terms of fret spacing. Default 0.25
+
+@item
+p:number -- set the position of the dot in the fret space. 0.5 is centered; 1 is on lower fret bar,
+0 is on upper fret bar. Default 0.6
+
+@item
+c:string1-string2-fret -- include a barre mark from string1 to string2 on fret
+
+@item
+string-fret -- place a dot on string at fret. If fret is o, string is identified
+as open. If fret is x, string is identified as muted.
+
+@item
+string-fret-fingering -- place a dot on string at fret, and label with fingering as
+defined by f: code.
+
+@end itemize
+
+@item
+Note: There is no limit to the number of fret indications per string.
+@end itemize
+
+"
+ (let ((definition-list (fret-parse-definition-string props definition-string)))
+ (make-fret-diagram layout (car definition-list) (cdr definition-list))))
+
+(define (fret-parse-definition-string props definition-string)
+ "parse a fret diagram string and return a pair containing:
+ props, modified as necessary by the definition-string
+ a fret-indication list with the appropriate values"
+ (let* ((fret-count 4)
+ (string-count 6)
+ (fret-range (list 1 fret-count))
+ (barre-list '())
+ (dot-list '())
+ (xo-list '())
+ (output-list '())
+ (new-props '())
+ (items (string-split definition-string #\;)))
+ (let parse-item ((myitems items))
+ (if (not (null? (cdr myitems)))
+ (let ((test-string (car myitems)))
+ (case (car (string->list (substring test-string 0 1)))
+ ((#\s) (let ((size (get-numeric-from-key test-string)))
+ (set! new-props (acons 'size size new-props))))
+ ((#\f) (let* ((finger-code (get-numeric-from-key test-string))
+ (finger-id (case finger-code
+ ((0) 'none)
+ ((1) 'in-dot)
+ ((2) 'below-string))))
+ (set! new-props
+ (acons 'finger-code finger-id new-props))))
+ ((#\c) (set! output-list (cons-fret (cons 'barre (numerify (string-split (substring test-string 2) #\-)))
+ output-list)))
+ ((#\h) (let ((fret-count (get-numeric-from-key test-string)))
+ (set! new-props (acons 'fret-count fret-count new-props))))
+ ((#\w) (let ((string-count (get-numeric-from-key test-string)))
+ (set! new-props (acons 'string-count string-count new-props))))
+ ((#\d) (let ((dot-size (get-numeric-from-key test-string)))
+ (set! new-props (acons 'dot-radius dot-size new-props))))
+ ((#\p) (let ((dot-position (get-numeric-from-key test-string)))
+ (set! new-props (acons 'dot-position dot-position new-props))))
+ (else
+ (let ((this-list (string-split test-string #\-)))
+ (if (string->number (cadr this-list))
+ (set! output-list (cons-fret (cons 'place-fret (numerify this-list)) output-list))
+ (if (equal? (cadr this-list) "x" )
+ (set! output-list (cons-fret (list 'mute (string->number (car this-list))) output-list))
+ (set! output-list (cons-fret (list 'open (string->number (car this-list))) output-list)))))))
+ (parse-item (cdr myitems)))))
+ (if (eq? new-props '())
+ `(,props . ,output-list)
+ `(,(cons new-props props) . ,output-list))))
+
+(define (cons-fret new-value old-list)
+" Put together a fret-list in the format desired by parse-string "
+ (if (eq? old-list '())
+ (list new-value)
+ (cons* new-value old-list)))
+
+(define (get-numeric-from-key keystring)
+ "Get the numeric value from a key of the form k:val"
+ (string->number (substring keystring 2 (string-length keystring))))
+
+(define (numerify mylist)
+ "Convert string values to numeric or character"
+ (if (null? mylist)
+ '()
+ (let ((numeric-value (string->number (car mylist))))
+ (if numeric-value
+ (cons* numeric-value (numerify (cdr mylist)))
+ (cons* (car (string->list (car mylist))) (numerify (cdr mylist)))))))
+
+(def-markup-command (fret-diagram-terse layout props definition-string)
+ (string?)
+ "Make a fret diagram markup using terse string-based syntax.
+
+Example
+@example
+ \\markup \\fret-diagram-terse #\"x;x;o;2;3;2;\"
+@end example
+for a D chord diagram.
+
+Syntax rules for @var{definition-string}:
+@itemize @bullet
+
+@item
+Strings are terminated by semicolons; the number of semicolons
+is the number of strings in the diagram.
+
+@item
+Mute strings are indicated by \"x\".
+
+@item
+Open strings are indicated by \"o\".
+
+@item
+A number indicates a fret indication at that fret.
+
+@item
+If there are multiple fret indicators desired on a string, they
+should be separated by spaces.
+
+@item
+Fingerings are given by following the fret number with a \"-\",
+followed by the finger indicator, e.g. 3-2 for playing the third
+fret with the second finger.
+
+@item
+Where a barre indicator is desired, follow the fret (or fingering) symbol
+with \"-(\" to start a barre and \"-)\" to end the barre.
+@end itemize"
+;TODO -- change syntax to fret\string-finger
+ (let ((definition-list (fret-parse-terse-definition-string props definition-string)))
+ (make-fret-diagram layout (car definition-list) (cdr definition-list))))
+
+(define (fret-parse-terse-definition-string props definition-string)
+ "parse a fret diagram string that uses terse syntax; return a pair containing:
+ props, modified to include the string-count determined by the definition-string
+ a fret-indication list with the appropriate values"
+;TODO -- change syntax to fret\string-finger
+ (let* ((barre-start-list '())
+ (output-list '())
+ (new-props '())
+ (items (string-split definition-string #\;))
+ (string-count (- (length items) 1)))
+ (let parse-item ((myitems items))
+ (if (not (null? (cdr myitems)))
+ (let* ((test-string (car myitems))
+ (current-string (- (length myitems) 1))
+ (indicators (string-split test-string #\ )))
+ (let parse-indicators ((myindicators indicators))
+ (if (not (eq? '() myindicators))
+ (let* ((this-list (string-split (car myindicators) #\-))
+ (max-element-index (- (length this-list) 1))
+ (last-element (car (list-tail this-list max-element-index)))
+ (fret (if (string->number (car this-list)) (string->number (car this-list)) (car this-list))))
+ (if (equal? last-element "(")
+ (begin
+ (set! barre-start-list (cons-fret (list current-string fret) barre-start-list))
+ (set! this-list (list-head this-list max-element-index))))
+ (if (equal? last-element ")")
+ (let* ((this-barre (get-sub-list fret barre-start-list))
+ (insert-index (- (length this-barre) 1)))
+ (set! output-list (cons-fret (cons* 'barre (car this-barre) current-string (cdr this-barre))
+ output-list))
+ (set! this-list (list-head this-list max-element-index))))
+ (if (number? fret)
+ (set! output-list (cons-fret (cons* 'place-fret current-string (drop-paren (numerify this-list))) output-list))
+ (if (equal? (car this-list) "x" )
+ (set! output-list (cons-fret (list 'mute current-string) output-list))
+ (set! output-list (cons-fret (list 'open current-string) output-list))))
+ (parse-indicators (cdr myindicators)))))
+ (parse-item (cdr myitems)))))
+ (set! new-props (acons 'string-count string-count new-props))
+
+ `(,(cons new-props props) . ,output-list)))
+
+(define (drop-paren item-list)
+" drop a final parentheses from a fret indication list resulting from a terse string specification of barre."
+ (if (> (length item-list) 0)
+ (let* ((max-index (- (length item-list) 1))
+ (last-element (car (list-tail item-list max-index))))
+ (if (or (equal? last-element ")") (equal? last-element "("))
+ (list-head item-list max-index)
+ item-list))
+ item-list))
+
+(define (get-sub-list value master-list)
+" Get a sub-list whose cadr is equal to @var{value} from @var{master-list}"
+ (if (eq? master-list '())
+ #f
+ (let ((sublist (car master-list)))
+ (if (equal? (cadr sublist) value)
+ sublist
+ (get-sub-list value (cdr master-list))))))