Re: fingering

[Aaron Hill]

On 2019-01-21 6:04 am, Gianmaria Lari wrote:
> Using your old code to draw a circle around finger number on the left 
> of
> the note today I found a problem. When I use "\omit Fingering" the
> compilation report me the error:
>
> programming error: Infinity or NaN encountered
>
> \omit Fingering <g'
>
> -2 c''-\cFS-4>
>
>
> Here it is a simple code showing the problem:
>
> [ . . . ]

This is all you need to trigger the error:

%%%%
\version "2.19.82"
{ \set fingeringOrientations = #'(left)
  \omit Fingering
  <g'-2 c''-4> }
%%%%

Not \setting fingeringOrientations or not \omitting Fingering results in 
a clean compile.  Also changing \omit to \hide works, although then 
there is extra space.

\omit * is basically \override *.stencil = ##f whereas \hide * is 
\override *.transparent = ##t.

My guess is the code that handles fingeringOrientations expects the 
stencil to be valid and is balking at the false value.  Looking at the 
code, I see the programming_error comes from grob.cc:318 which is within 
Grob::translate_axis.  The problem is that translate_axis gets called 
from so many different places.  Without a stack trace, this will be 
harder to track down.

This variation works:

%%%%
\version "2.19.82"
{ \set fingeringOrientations = #'(left)
  \override Fingering.stencil = #(lambda (grob)
    (ly:make-stencil '() '(0 . 0) '(0 . 0)))
  <g'-2 c''-4> }
%%%%

Here we have a valid, albeit empty, stencil.  This bypasses the 
programming error.

----

Ignoring the programming error, there is another issue with how \omit * 
behaves.  Consider the following:

%%%%
\version "2.19.82"

circledFingerStil = #(lambda (grob)
  (circle-stencil (ly:text-interface::print grob) 0.1 0.1))
cFS = \tweak stencil \circledFingerStil \etc

{ \omit Fingering
  <g'-2 c''-\cFS-4> }
%%%%

Using \omit Fingering is supposed to eliminate Fingering grobs until it 
is \undone.  The problem is that \tweak also modifies the stencil, 
cancelling out the effect of the \omit.


-- Aaron Hill