1 ;;;; fret-diagrams.scm --
3 ;;;; source file of the GNU LilyPond music typesetter
5 ;;;; (c) 2004--2007 Carl D. Sorensen <c_sorensen@byu.edu>
7 (define (fret-parse-marking-list marking-list fret-count)
8 (let* ((fret-range (list 1 fret-count))
13 (let parse-item ((mylist marking-list))
14 (if (not (null? mylist))
15 (let* ((my-item (car mylist)) (my-code (car my-item)))
17 ((or (eq? my-code 'open)(eq? my-code 'mute))
18 (set! xo-list (cons* my-item xo-list)))
20 (set! barre-list (cons* (cdr my-item) barre-list)))
21 ((eq? my-code 'place-fret)
22 (set! dot-list (cons* (cdr my-item) dot-list))))
23 (parse-item (cdr mylist)))))
24 ;; calculate fret-range
25 (let ((maxfret 0) (minfret 99))
26 (let updatemax ((fret-list dot-list))
29 (let ((fretval (second (car fret-list))))
30 (if (> fretval maxfret) (set! maxfret fretval))
31 (if (< fretval minfret) (set! minfret fretval))
32 (updatemax (cdr fret-list)))))
33 (if (> maxfret fret-count)
36 (let ((upfret (- (+ minfret fret-count) 1)))
37 (if (> maxfret upfret) maxfret upfret)))))
38 ; subtract fret from dots
39 (set! dot-list (subtract-base-fret (- (car fret-range) 1) dot-list)))
40 (acons 'fret-range fret-range
41 (acons 'barre-list barre-list
42 (acons 'dot-list dot-list
43 (acons 'xo-list xo-list '()))))))
45 (define (subtract-base-fret base-fret dot-list)
46 "Subtract @var{base-fret} from every fret in @var{dot-list}"
49 (let ((this-list (car dot-list)))
50 (cons* (list (car this-list) (- (second this-list) base-fret)
51 (if (null? (cddr this-list))
54 (subtract-base-fret base-fret (cdr dot-list))))))
56 (define (sans-serif-stencil layout props mag text)
57 "Create a stencil in sans-serif font based on @var{layout} and @var{props}
58 with magnification @var{mag} of the string @var{text}."
61 'font-size (stepmag mag)
62 (prepend-alist-chain 'font-family 'sans props))))
63 (interpret-markup layout my-props text)))
65 (define (draw-strings string-count fret-range th size orientation)
66 "Draw the string lines for a fret diagram with
67 @var{string-count} strings and frets as indicated in @var{fret-range}.
68 Line thickness is given by @var{th}, fret & string spacing by
69 @var{size}. Orientation is determined by @var{orientation}. "
70 (let* ((fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
71 (sl (* (+ fret-count 1) size))
73 (half-thickness (* sth 0.5))
76 (if (eq? orientation 'normal)
78 (list 'draw-line sth 0 0 0 sl)
79 (cons (- half-thickness) half-thickness)
80 (cons (- half-thickness) (+ sl half-thickness)))
82 (list 'draw-line sth 0 0 sl 0)
83 (cons (- half-thickness) (+ sl half-thickness))
84 (cons (- half-thickness) half-thickness)))))
85 (if (= string-count 1)
87 (if (eq? orientation 'normal)
88 (ly:stencil-combine-at-edge
89 (draw-strings (- string-count 1) fret-range th size orientation)
93 (ly:stencil-combine-at-edge
94 (draw-strings (- string-count 1) fret-range th size orientation)
99 (define (draw-fret-lines fret-count string-count th size orientation)
100 "Draw @var{fret-count} fret lines for a fret diagram
101 with @var{string-count} strings. Line thickness is given by @var{th},
102 fret & string spacing by @var{size}. Orientation is given by @var{orientation}"
103 (let* ((sth (* size th))
105 (fret-line (draw-fret-line string-count th size orientation)))
108 (if (eq? orientation 'normal)
109 (ly:stencil-combine-at-edge
111 (- fret-count 1) string-count th size orientation)
115 (ly:stencil-combine-at-edge
117 (- fret-count 1) string-count th size orientation)
122 (define (draw-fret-line string-count th size orientation)
123 "Draw a fret line for a fret diagram."
124 (let* ((fret-length (* (- string-count 1) size))
126 (half-thickness (* sth 0.5)))
127 (if (eq? orientation 'normal)
129 (list 'draw-line sth half-thickness size
130 (- fret-length half-thickness) size)
132 (cons (- half-thickness) half-thickness))
134 (list 'draw-line sth 0 half-thickness
135 0 (- fret-length half-thickness))
136 (cons (- half-thickness) half-thickness)
137 (cons 0 fret-length)))))
139 (define (draw-thick-zero-fret details string-count th size orientation)
140 "Draw a thick zeroth fret for a fret diagram whose base fret is not 1."
141 (let* ((sth (* th size))
143 (* sth (assoc-get 'top-fret-thickness details 3.0)))
144 (half-thick (* sth 0.5))
146 (x2 (+ half-thick (* size (- string-count 1))))
148 (y2 (+ top-fret-thick half-thick))
149 (x-extent (cons (- x1) x2))
150 (y-extent (cons sth top-fret-thick)))
151 (if (eq? orientation 'normal)
152 (ly:make-stencil (list 'round-filled-box x1 x2 y1 y2 sth)
154 (ly:make-stencil (list 'round-filled-box y1 y2 x1 x2 sth)
155 y-extent x-extent))))
157 (define (draw-frets fret-range string-count th size orientation)
158 "Draw the fret lines for a fret diagram with
159 @var{string-count} strings and frets as indicated in @var{fret-range}.
160 Line thickness is given by @var{th}, fret & string spacing by
161 @var{size}. Orientation is given by @var{orientation}."
162 (let* ((fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
163 (fret-length (* (- string-count 1) size))
164 (half-thickness (* th 0.5))
165 (base-fret (car fret-range))
166 (fret-zero (draw-fret-line string-count th size orientation)))
167 (if (eq? orientation 'normal)
168 (ly:stencil-combine-at-edge
169 (draw-fret-lines fret-count string-count th size orientation)
173 (ly:stencil-combine-at-edge
175 (draw-fret-lines fret-count string-count th size orientation)
178 (define (draw-dots layout props string-count fret-count
179 fret-range size finger-code
180 dot-position dot-radius dot-thickness dot-list orientation)
181 "Make dots for fret diagram."
183 (let* ((details (chain-assoc-get 'fret-diagram-details props '()))
184 (scale-dot-radius (* size dot-radius))
185 (scale-dot-thick (* size dot-thickness))
186 (dot-color (assoc-get 'dot-color details 'black))
187 (finger-xoffset -0.25)
188 (finger-yoffset (* -0.5 size ))
190 (* scale-dot-radius (assoc-get 'dot-label-font-mag details 1.0)))
191 (string-label-font-mag
192 (* size (assoc-get 'string-label-font-mag details 0.6)))
193 (mypair (car dot-list))
194 (restlist (cdr dot-list))
195 (string (car mypair))
197 (xpos (* size (if (eq? orientation 'normal)
198 (- string-count string)
199 (+ (- fret 1 ) dot-position))))
200 (ypos (* size (if (eq? orientation 'normal)
201 (+ 2 (- fret-count fret dot-position ))
202 (- string-count string))))
203 (extent (cons (- scale-dot-radius) scale-dot-radius))
204 (finger (caddr mypair))
205 (finger (if (number? finger) (number->string finger) finger))
206 (dotstencil (if (eq? dot-color 'white)
209 scale-dot-radius scale-dot-thick #t)
212 (- scale-dot-radius (* 0.5 scale-dot-thick))
216 scale-dot-radius scale-dot-thick #t)))
217 (positioned-dot (begin
218 (ly:stencil-translate-axis
219 (ly:stencil-translate-axis dotstencil xpos X)
222 (if (or (eq? finger '())(eq? finger-code 'none))
224 (if (eq? finger-code 'in-dot)
228 layout props dot-label-font-mag finger))))
229 (ly:stencil-translate-axis
230 (ly:stencil-translate-axis
233 (if (eq? dot-color 'white)
235 (ly:stencil-in-color finger-label 1 1 1)))
238 (if (eq? finger-code 'below-string)
241 (if (eq? orientation 'normal)
242 (ly:stencil-translate-axis
243 (ly:stencil-translate-axis
246 layout props string-label-font-mag finger))
248 (* size finger-yoffset) Y)
249 (ly:stencil-translate-axis
250 (ly:stencil-translate-axis
253 layout props string-label-font-mag finger))
254 (* size (+ 2 fret-count finger-yoffset)) X)
262 layout props string-count fret-count fret-range size finger-code
263 dot-position dot-radius dot-thickness restlist orientation)
264 labeled-dot-stencil))))
266 (define (draw-xo layout props string-count fret-range size xo-list orientation)
267 "Put open and mute string indications on diagram, as contained in
269 (let* ((details (chain-assoc-get 'fret-diagram-details props '()))
270 (fret-count (+ (- (cadr fret-range) (car fret-range) 1)))
272 (* size (assoc-get 'xo-font-magnification details 0.5)))
273 (xo-horizontal-offset (* size -0.35))
274 (mypair (car xo-list))
275 (restlist (cdr xo-list))
276 (glyph-string (if (eq? (car mypair) 'mute)
277 (assoc-get 'mute-string details "X")
278 (assoc-get 'open-string details "O")))
280 (+ (* (- string-count (cadr mypair)) size) xo-horizontal-offset ))
281 (glyph-stencil (if (eq? orientation 'normal)
282 (ly:stencil-translate-axis
284 layout props (* size xo-font-mag) glyph-string)
286 (ly:stencil-translate-axis
288 layout props (* size xo-font-mag) glyph-string)
294 layout props string-count fret-range size restlist orientation)
297 (define (make-bezier-sandwich-list start stop base height thickness orientation)
298 "Make the argument list for a bezier sandwich from
299 @var{start} to @var{stop} with a baseline at @var{base}, a height of
300 @var{height}, and a thickness of @var{thickness}. If @var{orientation} is
301 @var{'normal}, @var{base} is a y coordinate, otherwise it's an x coordinate."
302 (let* ((width (+ (- stop start) 1))
303 (x1 (+ (* width thickness) start))
304 (x2 (- stop (* width thickness)))
305 (bottom-control-point-height
306 (if (eq? orientation 'normal)
307 (+ base (- height thickness))
308 (- base (- height thickness))))
309 (top-control-point-height
310 (if (eq? orientation 'normal)
313 ; order of bezier control points is:
314 ; left cp low, right cp low, right end low, left end low
315 ; right cp high, left cp high, left end high, right end high.
316 (if (eq? orientation 'normal)
317 (list (cons x1 bottom-control-point-height)
318 (cons x2 bottom-control-point-height)
321 (cons x2 top-control-point-height)
322 (cons x1 top-control-point-height)
325 (list (cons bottom-control-point-height x1)
326 (cons bottom-control-point-height x2)
329 (cons top-control-point-height x2)
330 (cons top-control-point-height x1)
334 (define (draw-barre layout props string-count fret-range
335 size finger-code dot-position dot-radius
336 barre-list orientation)
337 "Create barre indications for a fret diagram"
338 (if (not (null? barre-list))
339 (let* ((details (chain-assoc-get 'fret-diagram-details props '()))
340 (string1 (caar barre-list))
341 (string2 (cadar barre-list))
342 (fret (caddar barre-list))
343 (top-fret (cadr fret-range))
344 (low-fret (car fret-range))
345 (barre-type (assoc-get 'barre-type details 'curved))
346 (scale-dot-radius (* size dot-radius))
347 (barre-vertical-offset 0.5)
348 ;; 2 is 1 for empty fret at bottom of figure + 1 for interval
349 ;; (top-fret - fret + 1) -- not an arbitrary constant
351 (* size (- (+ 2 (- (cadr fret-range) fret)) dot-position)))
352 (dot-center-fret-coordinate (+ (- fret low-fret) dot-position))
353 (barre-fret-coordinate
354 (+ dot-center-fret-coordinate
355 (* (- barre-vertical-offset 0.5) dot-radius)))
356 (barre-start-string-coordinate (- string-count string1))
357 (barre-end-string-coordinate (- string-count string2))
359 (+ dot-center-y (* barre-vertical-offset scale-dot-radius)))
360 (left (* size (- string-count string1)))
361 (right (* size (- string-count string2)))
365 (if (eq? orientation 'normal)
366 (make-bezier-sandwich-list
367 (* size barre-start-string-coordinate)
368 (* size barre-end-string-coordinate)
369 (* size (+ 1 (- top-fret fret) barre-fret-coordinate))
370 (* size bezier-height)
371 (* size bezier-thick)
373 (make-bezier-sandwich-list
374 (* size barre-start-string-coordinate)
375 (* size barre-end-string-coordinate)
376 (* size barre-fret-coordinate)
377 (* size bezier-height)
378 (* size bezier-thick)
381 (if (eq? barre-type 'straight)
382 (if (eq? orientation 'normal)
385 'draw-line (* size dot-radius) left dot-center-y
388 (cons (- dot-center-y scale-dot-radius)
389 (+ dot-center-y scale-dot-radius)))
391 (list 'draw-line (* size dot-radius)
392 (* size barre-fret-coordinate)
393 (* size barre-start-string-coordinate)
394 (* size barre-fret-coordinate)
395 (* size barre-end-string-coordinate))
396 (cons (- (* size barre-fret-coordinate)
398 (+ (* size barre-fret-coordinate)
400 (cons (* size barre-start-string-coordinate)
401 (* size barre-end-string-coordinate))))
402 (if (eq? orientation 'normal)
404 (list 'bezier-sandwich
405 `(quote ,bezier-list)
406 (* size bezier-thick))
408 (cons bottom (+ bottom (* size bezier-height))))
410 (list 'bezier-sandwich
411 `(quote ,bezier-list)
412 (* size bezier-thick))
413 (cons bottom (+ bottom (* size bezier-height)))
414 (cons left right))))))
415 (if (not (null? (cdr barre-list)))
418 (draw-barre layout props string-count fret-range size finger-code
419 dot-position dot-radius (cdr barre-list)))
422 (define (stepmag mag)
423 "Calculate the font step necessary to get a desired magnification"
424 (* 6 (/ (log mag) (log 2))))
426 (define (label-fret layout props string-count fret-range size orientation)
427 "Label the base fret on a fret diagram"
428 (let* ((details (chain-assoc-get 'fret-diagram-details props '()))
429 (base-fret (car fret-range))
430 (label-font-mag (assoc-get 'fret-label-font-mag details 0.5))
431 (label-vertical-offset
432 (assoc-get 'fret-label-vertical-offset details -0.2))
433 (number-type (assoc-get 'number-type details 'roman-lower))
434 (fret-count (+ (- (cadr fret-range) (car fret-range)) 1))
437 ((equal? number-type 'roman-lower)
438 (fancy-format #f "~(~:@r~)" base-fret))
439 ((equal? number-type 'roman-upper)
440 (fancy-format #f "~:@r" base-fret))
441 ((equal? 'arabic number-type)
442 (fancy-format #f "~d" base-fret))
443 (else (fancy-format #f "~(~:@r~)" base-fret)))))
444 (if (eq? orientation 'normal)
445 (ly:stencil-translate-axis
446 (sans-serif-stencil layout props (* size label-font-mag) label-text)
447 (* size (+ fret-count label-vertical-offset)) Y)
448 (ly:stencil-translate-axis
449 (sans-serif-stencil layout props (* size label-font-mag) label-text)
450 (* size (+ 1 label-vertical-offset)) X))))
452 (define-builtin-markup-command (fret-diagram-verbose layout props marking-list)
453 (list?) ; argument type
454 fret-diagram ; markup type
455 ((align-dir -0.4) ; properties and defaults
457 (fret-diagram-details)
459 "Make a fret diagram containing the symbols indicated in @var{marking-list}.
464 \\markup \\fret-diagram-verbose
465 #'((mute 6) (mute 5) (open 4)
466 (place-fret 3 2) (place-fret 2 3) (place-fret 1 2))
470 produces a standard D@tie{}chord diagram without fingering indications.
472 Possible elements in @var{marking-list}:
475 @item (mute @var{string-number})
476 Place a small @q{x} at the top of string @var{string-number}.
478 @item (open @var{string-number})
479 Place a small @q{o} at the top of string @var{string-number}.
481 @item (barre @var{start-string} @var{end-string} @var{fret-number})
482 Place a barre indicator (much like a tie) from string @var{start-string}
483 to string @var{end-string} at fret @var{fret-number}.
485 @item (place-fret @var{string-number} @var{fret-number} @var{finger-value})
486 Place a fret playing indication on string @var{string-number} at fret
487 @var{fret-number} with an optional fingering label @var{finger-value}.
488 By default, the fret playing indicator is a solid dot. This can be
489 changed by setting the value of the variable @var{dot-color}. If the
490 @var{finger} part of the @code{place-fret} element is present,
491 @var{finger-value} will be displayed according to the setting of the
492 variable @var{finger-code}. There is no limit to the number of fret
493 indications per string.
496 (make-fret-diagram layout props marking-list))
498 (define (make-fret-diagram layout props marking-list)
499 "Make a fret diagram markup"
501 ; note: here we get items from props that are needed in this routine,
502 ; or that are needed in more than one of the procedures
503 ; called from this routine. If they're only used in one of the
504 ; sub-procedure, they're obtained in that procedure
505 (size (chain-assoc-get 'size props 1.0)) ; needed for everything
506 ;TODO -- get string-count directly from length of stringTunings;
507 ; from FretBoard engraver, but not from markup call
508 ;TODO -- adjust padding for fret label? it appears to be too close to dots
511 'fret-diagram-details props '())) ; fret diagram details
513 (assoc-get 'string-count details 6)) ; needed for everything
515 (assoc-get 'fret-count details 4)) ; needed for everything
517 (assoc-get 'orientation details 'normal)) ; needed for everything
520 'finger-code details 'none)) ; needed for draw-dots and draw-barre
522 (if (eq? finger-code 'in-dot) 0.425 0.25)) ; bigger dots if labeled
523 (default-dot-position
524 (if (eq? finger-code 'in-dot)
525 (- 0.95 default-dot-radius)
526 0.6)) ; move up to make room for bigger if labeled
529 'dot-radius details default-dot-radius)) ; needed for draw-dots
533 'dot-position details default-dot-position)) ; needed for draw-dots
536 (* (ly:output-def-lookup layout 'line-thickness)
537 (chain-assoc-get 'thickness props 0.5))) ; needed for draw-frets
540 (chain-assoc-get 'align-dir props -0.4)) ; needed only here
542 (* size (assoc-get 'xo-padding details 0.2))) ; needed only here
543 (label-space (* 0.25 size))
544 (label-dir (assoc-get 'label-dir details RIGHT))
545 (parameters (fret-parse-marking-list marking-list fret-count))
546 (dot-list (cdr (assoc 'dot-list parameters)))
547 (xo-list (cdr (assoc 'xo-list parameters)))
548 (fret-range (cdr (assoc 'fret-range parameters)))
549 (barre-list (cdr (assoc 'barre-list parameters)))
550 (fret-diagram-stencil
552 (draw-strings string-count fret-range th size orientation)
553 (draw-frets fret-range string-count th size orientation))))
554 (if (not (null? barre-list))
555 (set! fret-diagram-stencil
557 (draw-barre layout props string-count fret-range size
558 finger-code dot-position dot-radius
559 barre-list orientation)
560 fret-diagram-stencil)))
561 (if (not (null? dot-list))
562 (set! fret-diagram-stencil
565 (draw-dots layout props string-count fret-count fret-range
566 size finger-code dot-position dot-radius
567 th dot-list orientation))))
568 (if (= (car fret-range) 1)
569 (set! fret-diagram-stencil
570 (if (eq? orientation 'normal)
571 (ly:stencil-combine-at-edge
572 fret-diagram-stencil Y UP
573 (draw-thick-zero-fret
574 props string-count th size orientation))
575 (ly:stencil-combine-at-edge
576 fret-diagram-stencil X LEFT
577 (draw-thick-zero-fret
578 props string-count th size orientation)))))
579 (if (not (null? xo-list))
580 (set! fret-diagram-stencil
581 (if (eq? orientation 'normal)
582 (ly:stencil-combine-at-edge
583 fret-diagram-stencil Y UP
584 (draw-xo layout props string-count fret-range
585 size xo-list orientation)
587 (ly:stencil-combine-at-edge
588 fret-diagram-stencil X LEFT
589 (draw-xo layout props string-count fret-range
590 size xo-list orientation)
592 (if (> (car fret-range) 1)
593 (set! fret-diagram-stencil
594 (if (eq? orientation 'normal)
595 (ly:stencil-combine-at-edge
596 fret-diagram-stencil X label-dir
597 (label-fret layout props string-count fret-range
600 (ly:stencil-combine-at-edge
601 fret-diagram-stencil Y label-dir
602 (label-fret layout props string-count fret-range
605 (ly:stencil-aligned-to fret-diagram-stencil X alignment)))
607 (define-builtin-markup-command (fret-diagram layout props definition-string)
608 (string?) ; argument type
609 fret-diagram ; markup category
610 (fret-diagram-verbose-markup) ; properties and defaults
611 "Make a (guitar) fret diagram. For example, say
614 \\markup \\fret-diagram #\"s:0.75;6-x;5-x;4-o;3-2;2-3;1-2;\"
618 for fret spacing 3/4 of staff space, D chord diagram
620 Syntax rules for @var{definition-string}:
624 Diagram items are separated by semicolons.
631 @code{s:}@var{number} -- Set the fret spacing of the diagram (in staff
636 @code{t:}@var{number} -- Set the line thickness (in staff spaces).
640 @code{h:}@var{number} -- Set the height of the diagram in frets.
644 @code{w:}@var{number} -- Set the width of the diagram in strings.
648 @code{f:}@var{number} -- Set fingering label type
649 (0@tie{}= none, 1@tie{}= in circle on string, 2@tie{}= below string).
653 @code{d:}@var{number} -- Set radius of dot, in terms of fret spacing.
657 @code{p:}@var{number} -- Set the position of the dot in the fret space.
658 0.5 is centered; 1@tie{}is on lower fret bar, 0@tie{}is on upper fret bar.
662 @code{c:}@var{string1}@code{-}@var{string2}@code{-}@var{fret} -- Include a
663 barre mark from @var{string1} to @var{string2} on @var{fret}.
666 @var{string}@code{-}@var{fret} -- Place a dot on @var{string} at @var{fret}.
667 If @var{fret} is @samp{o}, @var{string} is identified as open.
668 If @var{fret} is @samp{x}, @var{string} is identified as muted.
671 @var{string}@code{-}@var{fret}@code{-}@var{fingering} -- Place a dot on
672 @var{string} at @var{fret}, and label with @var{fingering} as defined
673 by the @code{f:} code.
677 Note: There is no limit to the number of fret indications per string.
679 (let ((definition-list
680 (fret-parse-definition-string props definition-string)))
681 (fret-diagram-verbose-markup
682 layout (car definition-list) (cdr definition-list))))
684 (define (fret-parse-definition-string props definition-string)
685 "Parse a fret diagram string and return a pair containing:
686 props, modified as necessary by the definition-string
687 a fret-indication list with the appropriate values"
688 (let* ((fret-count 4)
690 (fret-range (list 1 fret-count))
696 (details (merge-details 'fret-diagram-details props '()))
697 (items (string-split definition-string #\;)))
698 (let parse-item ((myitems items))
699 (if (not (null? (cdr myitems)))
700 (let ((test-string (car myitems)))
701 (case (car (string->list (substring test-string 0 1)))
702 ((#\s) (let ((size (get-numeric-from-key test-string)))
703 (set! props (prepend-alist-chain 'size size props))))
704 ((#\f) (let* ((finger-code (get-numeric-from-key test-string))
705 (finger-id (case finger-code
708 ((2) 'below-string))))
710 (acons 'finger-code finger-id details))))
711 ((#\c) (set! output-list
716 (string-split (substring test-string 2) #\-)))
718 ((#\h) (let ((fret-count (get-numeric-from-key test-string)))
720 (acons 'fret-count fret-count details))))
721 ((#\w) (let ((string-count (get-numeric-from-key test-string)))
723 (acons 'string-count string-count details))))
724 ((#\d) (let ((dot-size (get-numeric-from-key test-string)))
726 (acons 'dot-radius dot-size details))))
727 ((#\p) (let ((dot-position (get-numeric-from-key test-string)))
729 (acons 'dot-position dot-position details))))
731 (let ((this-list (string-split test-string #\-)))
732 (if (string->number (cadr this-list))
735 (cons 'place-fret (numerify this-list))
737 (if (equal? (cadr this-list) "x" )
740 (list 'mute (string->number (car this-list)))
744 (list 'open (string->number (car this-list)))
746 (parse-item (cdr myitems)))))
747 ; add the modified details
749 (prepend-alist-chain 'fret-diagram-details details props))
750 `(,props . ,output-list))) ;ugh -- hard-coded spell -- procedure better
752 (define (cons-fret new-value old-list)
753 "Put together a fret-list in the format desired by parse-string"
754 (if (eq? old-list '())
756 (cons* new-value old-list)))
758 (define (get-numeric-from-key keystring)
759 "Get the numeric value from a key of the form k:val"
760 (string->number (substring keystring 2 (string-length keystring))))
762 (define (numerify mylist)
763 "Convert string values to numeric or character"
766 (let ((numeric-value (string->number (car mylist))))
768 (cons* numeric-value (numerify (cdr mylist)))
769 (cons* (car (string->list (car mylist)))
770 (numerify (cdr mylist)))))))
772 (define-builtin-markup-command
773 (fret-diagram-terse layout props definition-string)
774 (string?) ; argument type
775 fret-diagram ; markup category
776 (fret-diagram-verbose-markup) ; properties
777 "Make a fret diagram markup using terse string-based syntax.
782 \\markup \\fret-diagram-terse #\"x;x;o;2;3;2;\"
786 for a D@tie{}chord diagram.
788 Syntax rules for @var{definition-string}:
793 Strings are terminated by semicolons; the number of semicolons
794 is the number of strings in the diagram.
797 Mute strings are indicated by @samp{x}.
800 Open strings are indicated by @samp{o}.
803 A number indicates a fret indication at that fret.
806 If there are multiple fret indicators desired on a string, they
807 should be separated by spaces.
810 Fingerings are given by following the fret number with a @code{-},
811 followed by the finger indicator, e.g. @samp{3-2} for playing the third
812 fret with the second finger.
815 Where a barre indicator is desired, follow the fret (or fingering) symbol
816 with @code{-(} to start a barre and @code{-)} to end the barre.
819 ;; TODO -- change syntax to fret\string-finger
820 (let ((definition-list
821 (fret-parse-terse-definition-string props definition-string)))
822 (fret-diagram-verbose-markup layout
823 (car definition-list)
824 (cdr definition-list))))
826 (define (fret-parse-terse-definition-string props definition-string)
827 "Parse a fret diagram string that uses terse syntax; return a pair containing:
828 props, modified to include the string-count determined by the
829 definition-string, and
830 a fret-indication list with the appropriate values"
831 ;TODO -- change syntax to fret\string-finger
833 (let* ((details (merge-details 'fret-diagram-details props '()))
834 (barre-start-list '())
837 (items (string-split definition-string #\;))
838 (string-count (- (length items) 1)))
839 (let parse-item ((myitems items))
840 (if (not (null? (cdr myitems)))
841 (let* ((test-string (car myitems))
842 (current-string (- (length myitems) 1))
843 (indicators (string-split test-string #\ )))
844 (let parse-indicators ((myindicators indicators))
845 (if (not (eq? '() myindicators))
846 (let* ((this-list (string-split (car myindicators) #\-))
847 (max-element-index (- (length this-list) 1))
849 (car (list-tail this-list max-element-index)))
851 (if (string->number (car this-list))
852 (string->number (car this-list))
854 (if (equal? last-element "(")
856 (set! barre-start-list
857 (cons-fret (list current-string fret)
860 (list-head this-list max-element-index))))
861 (if (equal? last-element ")")
863 (get-sub-list fret barre-start-list))
864 (insert-index (- (length this-barre) 1)))
866 (cons-fret (cons* 'barre
872 (list-head this-list max-element-index))))
879 (drop-paren (numerify this-list)))
881 (if (equal? (car this-list) "x" )
885 (list 'mute current-string)
890 (list 'open current-string)
892 (parse-indicators (cdr myindicators)))))
893 (parse-item (cdr myitems)))))
894 (set! details (acons 'string-count string-count details))
895 (set! props (prepend-alist-chain 'fret-diagram-details details props))
896 `(,props . ,output-list))) ; ugh -- hard coded; proc is better
898 (define (drop-paren item-list)
899 "Drop a final parentheses from a fret indication list
900 resulting from a terse string specification of barre."
901 (if (> (length item-list) 0)
902 (let* ((max-index (- (length item-list) 1))
903 (last-element (car (list-tail item-list max-index))))
904 (if (or (equal? last-element ")") (equal? last-element "("))
905 (list-head item-list max-index)
909 (define (get-sub-list value master-list)
910 "Get a sub-list whose cadr is equal to @var{value} from @var{master-list}"
911 (if (eq? master-list '())
913 (let ((sublist (car master-list)))
914 (if (equal? (cadr sublist) value)
916 (get-sub-list value (cdr master-list))))))
918 (define (merge-details key alist-list . default)
919 "Return ALIST-LIST entries for key, in one combined alist.
920 There can be two ALIST-LIST entries for a given key. The first
921 comes from the override-markup function, the second comes
922 from property settings during a regular override.
923 This is necessary because some details can be set in one
924 place, while others are set in the other. Both details
925 lists must be merged into a single alist.
926 Return DEFAULT (optional, else #f) if not
929 (define (helper key alist-list default)
930 (if (null? alist-list)
932 (let* ((handle (assoc key (car alist-list))))
934 (append (cdr handle) (chain-assoc-get key (cdr alist-list) '()))
935 (helper key (cdr alist-list) default)))))
937 (helper key alist-list
938 (if (pair? default) (car default) #f)))