Re: Collision on tremolo

[Thomas Morley]

Am Do., 11. Juni 2020 um 08:50 Uhr schrieb Pierre Perol-Schneider
<pierre.schneider.paris@gmail.com>:
>
> Hi Paolo,
>
> Le mer. 10 juin 2020 à 22:29, Paolo Prete <paolopr976@gmail.com> a écrit :
>>
>> Hello,
>>
>> as you can see in Lilybin's output, the below expression produces a 
>> collision:
>>
>> { \repeat tremolo 8 { aes'16 bes' } }
>>
>> http://lilybin.com/tmdugu/1
>>
>> What's wrong
>
>
> Definitly a bug.

Yep,
https://gitlab.com/lilypond/lilypond/-/issues/704
(there are some other related issues)
There you can find an image from Gould proposing tremolo-beams with
whole notes should be done as if there were stems. Alternatively
between the NoteHeads.

You may be interested in
http://lilypond.1069038.n5.nabble.com/Proposal-Changing-tremolo-beam-gap-implementation-td230988.html
and
http://lilypond.1069038.n5.nabble.com/Whole-note-tremolo-beams-td230689.html
where I try to propose some code for the note-head centered alternative.

Paolo, if you try my code from there (tremolo-gap.ly), you'll notice
the Beam comes out very short. You may want to lengthen it.
Furthermore, to get the appearance of between-invisible-stems tremolo,
apply a positions-override as demonstrated by Pierre already:

%% include the code from tremolo-gap.ly
{
    \override Beam.springs-and-rods = #ly:spanner::set-spacing-rods
    \override Beam.minimum-length = 8
    %\override Beam.positions = #'(3 . 3.5)
    \repeat tremolo 8 { aes'16 bes' }
}

Torsten planned to provide a patch, though I don't know the current
status. cc-ing him.

Cheers,
  Harm