Re: Variable slur thickness

[Thomas Morley]

2016-03-11 14:31 GMT+01:00 Sharon Rosner <address@hidden>:
>> I've managed to bypass using before-line-breaking AND after-line-breaking
>> by assigning the function to the 'thickness property and having each grob
>> internally calculate its own control points rather than relying on it
>> being
>> calculated elsewhere (also attached):
>
> Works great! I improved it further by making it compatible with ties too:
>
>
> #(define (variable-slur-thickness min-l max-l min-t max-t) (lambda (grob)
>   (let* ((cpf (if (grob::has-interface grob 'tie-interface)
>                   ly:tie::calc-control-points
>                   ly:slur::calc-control-points))
>          (cpt (cpf grob))
>          (cp0 (car cpt)) (cp3 (cadddr cpt))
>          (dx (- (car cp3) (car cp0)))
>          (dy (- (cdr cp3) (cdr cp0)))
>          (len (magnitude (make-rectangular dx dy)))
>          (thickness
>            (cond ((< len min-l) min-t)
>                  ((> len max-l) max-t)
>                  (else (+ min-t (* (- len min-l)
>                          (/ (- max-t min-t) (- max-l min-l))))))))
>
>          thickness)))
>
>
>> The only thing I'm (slightly) concerned with is
>> the duplicate control-point calculation in this function and how it might
>> affect compilation times if this were applied to a large orchestral score,
>> for example.
>
> A preliminary check with a 17-page score shows a pretty negligible effect on
> compilation time, 0.6s (the total time is about 21s), or about 2.7%
> additional compilation time. A small price to pay for more beauty!
>
> Sharon



How about below,
Should work for all bows, hence the name is changed

#(define (variable-bow-thickness min-l max-l min-t max-t)
  (lambda (grob)
    ;; Get the procedure to calculate the control-points
    ;; If none use `fall-back' to return a default-value for 'thickness
    (let ((cpf (assoc-get 'control-points (ly:grob-basic-properties grob)))
          (fall-back 1.2))
      (if (procedure? cpf)
          (let* ((cpt (cpf grob))
                 (cp0 (car cpt))
                 (cp3 (cadddr cpt))
                 (dx (- (car cp3) (car cp0)))
                 (dy (- (cdr cp3) (cdr cp0)))
                 (len (magnitude (make-rectangular dx dy)))
                 (thickness
                   (cond ((< len min-l) min-t)
                         ((> len max-l) max-t)
                         (else (+ min-t (* (- len min-l)
                               (/ (- max-t min-t) (- max-l min-l))))))))
            thickness)
          fall-back))))


Cheers,
 Harm