Re: Piano/Xylophone key diagrams

[Phil Holmes]

----- Original Message ----- 
From: "Thomas Morley" <address@hidden>
To: "David Kastrup" <address@hidden>
Cc: "lilypond-user" <address@hidden>
Sent: Saturday, October 12, 2013 2:29 PM
Subject: Re: Piano/Xylophone key diagrams


> 2013/10/12 David Kastrup <address@hidden>:
> > "Phil Holmes" <address@hidden> writes:
> >
> > > At college, one of my ensembles is a mixed-music group performing
> > > modern music.  I normally get away with singing or "playing" a
> > > triangle and bits of other untuned percussion.  Imagine my surprised
> > > when I was given a xylophone piece to play.  Fortunately, it's only
> > > one note at a time, and most of them are the same note, repeated for
> > > four bars, so I generally have the time to work out where the next key
> > > is when I'm playing the current one.  However, I thought it might be
> > > interesting and vaguely useful to have some piano key diagrams which
> > > show which key is to be played, rather like the fingering diagrams.
> > > The attached image illustrates the kind of thing: playing D#.
> > >
> > > I know I could use box, rounded-box or filled-box, or moveto/lineto
> > > commands to draw the boxes, so I clearly could create the diagrams
> > > individually for each note.  However, I thought it would be better to
> > > create a function to do this.  I'd presume the location of each box
> > > would be in some sort of array/list, and that the function would use
> > > the 'pitch of the note to determine which to fill.  However, I've read
> > > our documentation on scheme and am stuck on how to start, either
> > > creating the array/list and iterating over it to draw boxes, or
> > > grabbing the pitch value of a note.
> > >
> > > Could anyone start me off on this and help when I get stuck again?
> >
> > Starting off would be on
> > <URL:http://code.google.com/p/lilypond/issues/detail?id=3563#c4>.  Check
> > its output.  This is basically what you need, except that you need to
> > replace the C-Griff function which uses filled and non-filled circles in
> > a three-row arrangement with a more tedious rectangular arrangement.
> >
> > The c-griff function here only does the formatting and would need to be
> > completely replaced.  In contrast, the stuff in define-scheme-function
> > could be kept unchanged.
>
> Or maybe
> http://lsr.dsi.unimi.it/LSR/Item?id=791
> might give some inspiration.
>
> Cheers,
>  Harm

Thanks to David and Harm for their suggestions.  For now I've gone with 
adapting what Harm suggested - I've tidied the code a little and added a 
scaling parameter that varies the width of the keys and the size of the dot. 
Example output is attached, together with the file used to create this.

--
Phil Holmes

Keys_new.png
Description: PNG image

Keys_new.ly
Description: Text Data