Re: Piano pedalling

[Jan Nieuwenhuizen]

Chris Jackson <address@hidden> writes:

> I'm trying to investigate how to implement the
> |___/\_______/\__________|  style of piano sustain pedalling.

Yes, there've been several requests for that feature.

> Adding a 'edge-width' property to the generic text spanner, to go with
> 'edge-height' doesn't look too hard.

Ok, and we also might use that (or something similar) for our tuplet
spanner.

>  Then a macro, such as \sustainBracketStart/Stop/Restart, might be
> written to start and stop the text spanner with the required
> properties set to sensible values.

I think it would be better to keep \sustainStart \sustainStop etc, and
set another property: Staff.SustainPedal type = bracket.

> But what would be the best way of ensuring that successive brackets on
> the same staff are automatically typeset at the same y-distance below
> the staff, without having to hand-tweak the properties every time the
> notes go too low? 

You can use the same tactic that's used to vertically align the
absolute dynamics, like p, f, with hairpin crescendi and decrescendi.
If you look at dynamic-engraver.cc, you'll see that all dynamics are
added to a simple Spanner (line_spanner_).

In the case of dynamics, only a consecutive sequence symbols are
aligned (in one Spanner), which makes the code a lot hairier.  For
piano pedal brackets you'll probably just want to align them all using
the same spanner.

Greetings,
Jan.

-- 
Jan Nieuwenhuizen <address@hidden> | GNU LilyPond - The music typesetter
http://www.xs4all.nl/~jantien       | http://www.lilypond.org