Re: Maintaining font-size regardless of staff-size

[David Sumbler]

On Fri, 2018-05-18 at 13:37 +0200, David Kastrup wrote:
> David Sumbler <address@hidden> writes:
> 
> > 
> > %%%%%%%%%%%%%%%%%%
> > \version "2.19.81"
> > 
> > #(set-global-staff-size 20)
> > \book {
> >   \bookOutputName "test1"
> >   \header { title = \markup \fontsize #10 "fontsize 10" }
> >   { c''1 }
> > }
> > 
> > #(set-global-staff-size 10)
> > \book {
> >   \bookOutputName "test2"
> >   \header { title = \markup \fontsize #16 "fontsize 16" }
> >   { c''1 }
> > }
> > %%%%%%%%%%%%%%%%%%
> > 
> > Here the text in the second output file is correctly sized, but
> > with
> > the horizontal spacing only half what it should be.  It is similar
> > to
> > the problem found with \abs-fontsize.
> > 
> > However, in this case the problem is unlikely to be an issue in
> > practice, because the only circumstances I have found in which it
> > occurs are when (a) the second staff size is exactly half (or
> > double)
> > the first staff size, AND (b) the second fontsize is smaller (or
> > greater) than the first by exactly 6.
> > 
> > Weird, eh?
> No.  Fontsize is defined in terms of 6th roots of 2.  So basically
> you
> are producing a font with quite exactly the same size.  LilyPond is
> likely reusing some aspect of it but then botches the spacing.

Yes, I assumed that the 6th root of 2 matter was behind the anomaly.
 But it's still a bug.

David