--- /dev/null
+(define nil '())
+(define (fret-parse-string definition-string)
+ "parse a fret diagram string and return an alist with the appropriate values"
+ (let* ((fret-count 4)
+ (string-count 6)
+ (thickness 0.05)
+ (finger-code 0)
+ (dot-size 0.25)
+ (position 0.6)
+ (fret-range (list 1 fret-count))
+ (barre-list '())
+ (dot-list '())
+ (xo-list '())
+ (output-list '())
+ (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)))
+ ((#\f) (set! finger-code (get-numeric-from-key test-string)))
+ ((#\t) (set! thickness (get-numeric-from-key test-string)))
+ ((#\c) (set! barre-list (cons* (numerify (string-split (substring test-string 2) #\-))
+ barre-list)))
+ ((#\h) (set! fret-count (get-numeric-from-key test-string)))
+ ((#\w) (set! string-count (get-numeric-from-key test-string)))
+ ((#\d) (set! dot-size (get-numeric-from-key test-string)))
+ ((#\p) (set! position (get-numeric-from-key test-string)))
+ (else
+ (let ((this-list (string-split test-string #\-)))
+ ;(display this-list)
+ (if (string->number (cadr this-list))
+ (set! dot-list (cons* (numerify this-list) dot-list))
+ (set! xo-list (cons* (numerify this-list) xo-list))))))
+ (parse-item (cdr myitems)))))
+ ; calculate fret-range
+ (let ((maxfret 0) (minfret 99))
+ (let updatemax ((fret-list dot-list))
+ (if (null? fret-list)
+ '()
+ (let ((fretval (cadar 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 "string-count" string-count
+ (acons "dot-size" dot-size
+ (acons "position" position
+ (acons "finger-code" finger-code
+ (acons "fret-range" fret-range
+ (acons "thickness" thickness
+ (acons "barre-list" barre-list
+ (acons "dot-list" dot-list
+ (acons "xo-list" xo-list '())))))))))))
+
+(define (subtract-base-fret base-fret dot-list)
+
+ (if (null? dot-list)
+ '()
+ (let ((this-list (car dot-list)))
+ (cons* (list (car this-list) (- (cadr this-list) base-fret) (if (null? (cddr this-list))
+ nil
+ (caddr this-list)))
+ (subtract-base-fret base-fret (cdr dot-list))))))
+
+(define (draw-strings string-count fret-range th size)
+ (let* ((fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
+ (sl (* (+ fret-count 1) size))
+ (half-thickness (* th 0.5))
+ (string-stencil (ly:make-stencil (list 'draw-line th 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) 0 1
+ string-stencil
+ (- size th) 0))))
+
+(define (draw-fret-lines fret-count string-count th size)
+ (let* ((fret-length (* (- string-count 1) size))
+ (half-thickness (* th 0.5))
+ (fret-line (ly:make-stencil (list 'draw-line th 0 size fret-length 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)
+ (- size th) 0))))
+
+(define (draw-frets paper fret-range string-count th 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-fret-lines 1 string-count (* th 2) size)
+ (draw-fret-lines 1 string-count th size))
+ (- size th) 0)))
+
+(define (draw-dots paper string-count fret-range size dot-size position finger-code dot-list)
+ "Make dots for fret diagram."
+ (let* ((dot-radius (* size dot-size))
+ (fret-count (+ (- (cadr fret-range) (car fret-range) 1)))
+ (mypair (car dot-list))
+ (restlist (cdr dot-list))
+ (xpos (* (- string-count (car mypair)) size))
+ (ypos (* (+ 4 (- fret-count (cadr mypair) position )) size))
+ (finger (caddr mypair))
+ (font (ly:paper-get-font paper `(((font-magnification . ,(* 0.8 size))(font-name . "cmss8")
+ (font-encoding Tex-text)))))
+ (font2 (ly:paper-get-font paper `(((font-magnification . ,(* (* 2 dot-size) size))(font-name . "cmss8")
+ (font-encoding Tex-text)))))
+ (font3 (ly:paper-get-font paper `(((font-magnification . ,(* (* 3 dot-size) size))(font-name . "cmss8")
+ (font-encoding Tex-text)))))
+ (extent (cons (- (* size 0.25)) (* size 0.25)))
+ (dotstencil (if (or (eq? finger nil)(eq? finger-code 0))
+ (ly:make-stencil (list 'dot xpos ypos dot-radius ) extent extent)
+ (if (eq? finger-code 1)
+ ; TODO -- Get nice circled numbers in the font, instead of this kludge
+ (ly:stencil-add
+ (ly:stencil-translate-axis
+ (ly:stencil-translate-axis
+ (fontify-text font2 (number->string finger)) (- xpos (* size 0.3)) X)
+ (- ypos (* 1 dot-size size)) Y)
+ (ly:stencil-translate-axis
+ (ly:stencil-translate-axis
+ (fontify-text font3 "O") (- xpos (* 2.2 dot-size size)) X)
+ (- ypos (* 1.7 dot-size size)) Y))
+ (if (eq? finger-code 2)
+ (ly:stencil-add
+ (ly:make-stencil (list 'dot xpos ypos dot-radius ) extent extent)
+ (ly:stencil-translate-axis
+ (ly:stencil-translate-axis
+ (fontify-text font (number->string finger)) (- xpos (* size 0.3)) X)
+ (- size) Y)))))))
+ (if (null? restlist)
+ dotstencil
+ (ly:stencil-add (draw-dots paper string-count fret-range size dot-size position finger-code restlist)
+ dotstencil))))
+
+(define (draw-xo paper string-count fret-range size xo-list)
+"Put x and o on chord diagram."
+ (let* ((dot-radius (* size 0.25))
+ (fret-count (+ (- (cadr fret-range) (car fret-range) 1)))
+ (font (ly:paper-get-font paper `(((font-size . ,(* -5 (+ 1 (* 2.6 (- 1 size)))))(font-family . music)))))
+ (mypair (car xo-list))
+ (restlist (cdr xo-list))
+;TODO -- get better glyphs in font to use for x (mute string) and o (open string)
+; Perhaps explore just using sans-serif font?
+ (glyph-name (if (char=? (cadr mypair) #\x) "noteheads-2cross"
+ "scripts-open"))
+ (tmpdot (if (char=? (cadr mypair) #\x) 0 (* size 0.25)))
+ (xpos (if (char=? (cadr mypair) #\x)
+ (- (* (- string-count (car mypair)) size) (* .35 size) )
+ (* (- string-count (car mypair)) size)))
+ (ypos (* (+ 3.5 fret-count) size))
+ (extent (cons (- (* size 0.25)) (* size 0.25)))
+ (glyph-stencil (ly:stencil-translate-axis
+ (ly:stencil-translate-axis (ly:find-glyph-by-name font glyph-name) ypos Y)
+ xpos X)))
+ (if (null? restlist)
+ glyph-stencil
+ (ly:stencil-add
+ (draw-xo paper string-count fret-range size restlist)
+ glyph-stencil))))
+
+(define (make-bezier-sandwich-list left right bottom height thickness)
+ (let* ((width (+ (- right left) 1))
+ (x1 (+ (* width 0.1) left))
+ (x2 (- right (* width 0.1)))
+ (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 paper string-count fret-range size barre-list)
+ "Create barre indications for a chord diagram"
+ (if (not (null? barre-list))
+ (let* ((string1 (caar barre-list))
+ (string2 (cadar barre-list))
+ (fret (caddar barre-list))
+ (bottom (* size (+ 1.5 (- (cadr fret-range) fret))))
+ (left (* size (- string-count string1)))
+ (right (* size (- string-count string2)))
+ (bezier-list (make-bezier-sandwich-list left right bottom (* size 0.5) (* size 0.1)))
+ (sandwich-stencil (ly:make-stencil (list 'bezier-sandwich `(quote ,bezier-list) (* size 0.1) )
+ (cons 0 right)
+ (cons 0 (+ bottom (* size 0.8))))))
+ (if (not (null? (cdr barre-list)))
+ (ly:stencil-add sandwich-stencil
+ (draw-barre paper string-count fret-range size (cdr barre-list)))
+ sandwich-stencil ))))
+
+(define (label-fret paper string-count fret-range size)
+ "Label the base fret on a fret diagram"
+ (let ((base-fret (car fret-range))
+ (fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
+ (font (ly:paper-get-font paper `(((font-magnification . ,(* 0.8 size))(font-name . "cmss8")
+ (font-encoding Tex-text))))))
+ (ly:stencil-translate-axis
+ (ly:stencil-translate-axis (fontify-text font (if (> base-fret 1)
+ (format #f "~(~:@r~)" base-fret)
+ " ")) (* (- string-count 0.5) size) X)
+ (* (- fret-count 0.2) size) Y)))
+
+(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)))))))
+
+
+(define (make-fret-diagram paper size definition-string)
+ "Make a fret diagram"
+ (let* ((parameters (fret-parse-string definition-string))
+ (string-count (cdr (assoc "string-count" parameters)))
+ (fret-range (cdr (assoc "fret-range" parameters)))
+ (finger-code (cdr (assoc "finger-code" parameters)))
+ (dot-size (cdr (assoc "dot-size" parameters)))
+ (position (cdr (assoc "position" parameters)))
+ (dot-list (cdr (assoc "dot-list" parameters)))
+ (xo-list (cdr (assoc "xo-list" parameters)))
+ (line-thickness (cdr (assoc "thickness" parameters)))
+ (barre-list (cdr (assoc "barre-list" parameters)))
+ (fret-diagram-stencil (ly:stencil-add
+ (draw-strings string-count fret-range line-thickness size)
+ (draw-frets paper fret-range string-count line-thickness size))))
+ (if (not (null? dot-list))
+ (set! fret-diagram-stencil (ly:stencil-add
+ (draw-dots paper string-count fret-range size dot-size position finger-code dot-list)
+ fret-diagram-stencil)))
+ (if (not (null? xo-list))
+ (set! fret-diagram-stencil (ly:stencil-add
+ (draw-xo paper string-count fret-range size xo-list)
+ fret-diagram-stencil)))
+ (if (not (null? barre-list))
+ (set! fret-diagram-stencil (ly:stencil-add
+ (draw-barre paper string-count fret-range size barre-list)
+ fret-diagram-stencil)))
+ (set! fret-diagram-stencil (ly:stencil-add fret-diagram-stencil (label-fret paper string-count fret-range size)))
+ (ly:stencil-align-to! fret-diagram-stencil X -.4)
+ fret-diagram-stencil))
+
+(def-markup-command (fret-diagram paper props size definition-string)
+ (number? string?)
+ "Syntax: \\fret-diagram size definition-string
+ eg: \\markup \\fret-diagram #0.75 #\"6-x;5-x;4-o;3-2;2-3;1-2;\"
+ for fret spacing 3/4 of staff space, D chord diagram
+ Syntax rules for @var{definition-string}:
+ Diagram items are separated by semicolons.
+ Possible items:
+ t:number -- set the line thickness (in staff spaces). Default 0.05
+ h:number -- set the height of the diagram in frets. Default 4
+ w:number -- set the width of the diagram in strings. Default 6
+ f:number -- set fingering label type
+ (0 = none, 1 = in circle on string, 2 = below string) Default 0
+ d:number -- set radius of dot, in terms of fret spacing. Default 0.25
+ 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
+ c:string1-string2-fret -- include a barre mark from string1 to string2 on fret
+ 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.
+ string-fret-fingering -- place a dot on string at fret, and label with fingering as
+ defined by f: code.
+ Note: There is no limit to the number of fret indications per string."
+ (make-fret-diagram paper size definition-string))