Re: \startTrillSpan without the tr at the beginning?

[Richard Shann]

On Sun, 2015-01-25 at 12:03 +0100, Pierre Perol-Schneider wrote:
> Try :
> 
> \version "2.18.2"
> 
> {
>   b'-\tweak bound-details.left.text #'() 

I've started to look more deeply to see if the sharp zig-zag line could
be replaced by a user-defined line. I found this

8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
http://lilypond.org/doc/v2.18/Documentation/internals/trillspanner

 stencil (stencil):

    ly:line-spanner::print

    The symbol to print. 
8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
This sounds strange - I would guess stencil is a procedure not a glyph
(? what would symbol mean here?) - and indeed the next entry on that
page is
8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
 style (symbol):

    'trill

    This setting determines in what style a grob is typeset. Valid
choices depend on the stencil callback reading this property. 
8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><

Is it on the cards to write some scheme procedure that stencil could be
set to in order generate a more wavy line?


Richard