Re: Strange gap-behaviour with whole-note tremolo Beams

[Thomas Morley]

Am Fr., 27. März 2020 um 14:51 Uhr schrieb Torsten Hämmerle
<address@hidden>:
>
> Thomas Morley-2 wrote
> > I have no clue why this happens and where those added values came from.
> >
> > Any insights?
>
>
> Hi Harm,
>
>
> Believe it or not, this strange (and certainly unintended) effect is caused
> by the thickness of the invisible stems!
>
> The beam shortening will actually depend on the beam thickness, as the beams
> will start at the left side of the left beam and end at the right side of
> the right beam.
> For further investigation, I've added a layout block to your example:
>
>
> %%%%%%
> \layout {
>   \context {
>     \Voice
>     \override Stem.thickness = #100   % standard: 1.3
>   }
> }
> %%%%%%
>
> Obviously, the beam shortening deviations will start even earlier when using
> stem thickness 0 and they will start later as the stem thickness increases.
> When setting the stem thickness to approximately 50 or above, the stem
> shortening deviations will vanish in all of your test cases (I hope the
> table will be correctly displayed in raw format):
>
>
>
> So I guess this unintended dependency on invisible beam thicknesses comes
> from within the C++ code will have to be corrected there.
>
> I'll open up a tracker issue and see what I can do about it.
>
> HTH,
> Torsten
>
>
>
> --
> Sent from: http://lilypond.1069038.n5.nabble.com/User-f3.html
>

Hi Torsten,

thanks for your findings!!

Though, setting Stem.thickness zero, results in consistent shortening
values on my maschine, _if_ 'gap <= 2.
With 'gap > 2 the deviation is indeed increased.

Though, setting Stem.thickness 50 results in _always_ consistent
behaviour, at least so far tested.

I can't imagine any reason for it, thus I'd say it qualifies for a bug.
Obviously you think alike, thanks for opening a ticket:
https://sourceforge.net/p/testlilyissues/issues/5868/


Best,
  Harm