Re: Dotted ottava bracket

[David Nalesnik]

Hi,

On Fri, Feb 13, 2015 at 6:07 AM, Pierre Perol-Schneider <address@hidden> wrote:

Hi Joram,

Two things :
1) Ottava_spanner_engraver is part of the Staff context, see : http://lilypond.org/doc/v2.18/Documentation/internals/ottava_005fspanner_005fengraver

2) for some reason LP spanners cannot reproduce dotted lines such as the one your looking for.

LilyPond draws both dotted lines and dashed lines using code for drawing dashed lines.  This sounds irrational, but it makes sense in that a dot is simply a dash where the line part has no length, but the rounded end-cap of the line (a superimposed circle) appears.   Whenever you set style to 'dotted-line, the dash-fraction gets set to 0 automatically.  

The problem is that line-thickness is getting added into the mix.  Thus, in your original snippet, by setting thickness to 2, the program ends up drawing a short line in addition to the rounded end caps.  Of course, if you set thickness to 0, nothing appears--the end-cap has diameter of 0, too.

(See https://code.google.com/p/lilypond/issues/detail?id=4103 for a related discussion.)

This is definitely a problem.  It doesn't look like this should be too hard to fix.  (Famous last words.)  I'll see about making a patch.

--David