Re: Tuplet bracket and cross staff

[David Nalesnik]

Hi Harm,

On Sun, Jun 26, 2016 at 3:53 AM, Thomas Morley <address@hidden> wrote:
> 2016-06-26 5:00 GMT+02:00 Andrew Bernard <address@hidden>:
>>  Hi Matteo,
>>
>> I have a tuplet angle function that somebody (I cannot recall who)
>> sent me some time ago. I use it heavily and extensively and I can say
>> it has been tested by me to the limit - it works well.
>>
>> Using this code you just say \tupletAngles 1 0 or similar and that's
>> all you need. Put it is a file tuplet-angles.ily and include it. Using
>> \tupletAngles 0 0 is very handy for straigthening up tuplets when you
>> don't want lilypond to angle them.
>>
>> Here it is. [Surprised this is not more well known.]
>>
>> Andrew
>
> Looking in the archives:
> http://lilypond.1069038.n5.nabble.com/angle-of-a-tuplet-bracket-td55019.html#a55023
> :)
>

A very useful function!

It occurs to me that you could override 'positions directly without
consulting the stencil, instead of as a side-effect:


%% ===========================================
tupletAngles =
#(define-music-function (y-off angl)(number? number?)
   "
 y-off a (possible) offset in Y-direction
 angl is supposed to be the angle of the TupletBracket in degrees,
 "
   #{
     \once\override TupletBracket #'positions =
     #(lambda (grob)
        (let* ((pos (ly:tuplet-bracket::calc-positions grob))
               (y-length (interval-length pos))
               (x-length (interval-length
(ly:tuplet-bracket::calc-x-positions grob)))
               (alpha (degrees->radians angl))
               (dir (ly:grob-property grob 'direction))
               (new-start (+ (if (= dir 1)
                                 (max (car pos)(cdr pos))
                                 (min (car pos)(cdr pos)))
                            y-off))
               (new-y (* x-length (tan alpha))))
          (cons new-start (+ new-start new-y))))
   #})

horizontalTuplets =
\override TupletBracket  #'positions =
#(lambda (grob)
   (let* ((pos (ly:tuplet-bracket::calc-positions grob))
          (dir (ly:grob-property grob 'direction))
          (new-pos (if (= dir 1)
                       (max (car pos)(cdr pos))
                       (min (car pos)(cdr pos)))))
     (cons new-pos new-pos)))

%% ===========================================

(For newer versions, maybe it would be helpful to work in the
grob-transformer function?)

--DN