Re: pdf changes every few compilations, although changing nothing

[David Nalesnik]

On Mon, Apr 10, 2017 at 7:21 AM, Thomas Morley <address@hidden> wrote:
> 2017-04-10 14:09 GMT+02:00 David Nalesnik <address@hidden>:
>> On Mon, Apr 10, 2017 at 5:36 AM, Thomas Morley <address@hidden> wrote:
>
>>> Here the best minimal I can come up with:
>>>
>>> \version "2.19.60"
>>>
>>> tst = {
>>>     \override TupletBracket.stencil =
>>>     #(lambda (grob)
>>>        (let* ((orig (ly:grob-original grob))
>>>               (siblings (if (ly:grob? orig) (ly:spanner-broken-into orig) 
>>> '()))
>>>               (tuplet-number (ly:grob-object grob 'tuplet-number)))
>>>          (if (or (and (pair? siblings)
>>>                       (equal? grob (car siblings)))
>>>                  (null? siblings))
>>>              (ly:grob-set-property! tuplet-number 'X-offset 0))
>>>          (ly:tuplet-bracket::print grob)))
>>>     }
>>>
>>> %%{
>>> \new Staff { \tst \tuplet 1/1 { \repeat unfold 30 c'1 } }
>>> %}
>>> %%{
>>> \new Staff { \tst \tuplet 1/1 { c'1 c'1 c' c' c' } }
>>> %}
>>>
>>>
>>
>> I notice the same variability with 2.19.56 and 2.18.2.  I'll see if I
>> can figure out more.
>
>
> Hi David,
>
> many thanks for caring.
>
> I meanwhile found using 'after-line-breaking and setting the final
> stencil via ly:grob-set-property! ensures stable behaviour.
>
> Nevertheless I stay highly interested why this happens during a direct
> stencil-override.
>

Here's an even more minimal example:


tst = \override TupletBracket.stencil =
#(lambda (grob)
   (let ((tuplet-number (ly:grob-object grob 'tuplet-number)))
     (ly:grob-set-property! tuplet-number 'X-offset 0)
     (ly:tuplet-bracket::print grob)))

%%{
\new Staff { \tst \tuplet 1/1 { \repeat unfold 30 c'1 } }
%}
%%{
\new Staff { \tst \tuplet 1/1 { c'1 c'1 c' c' c' } }

%%

It's strange -- it seems that the value of
ly:tuplet-bracket::calc-x-offset is used sometimes regardless of the
ly:grob-set-property! and there's no predictability to it.

No idea :(

-David