On Mon, Oct 24, 2011 at 4:09 PM, Thomas Morley
<address@hidden> wrote:
Hi David,
2011/10/24 David Nalesnik
<address@hidden>
The examples that Gould shows (pg. 158) have the peak of the feathered beams aligned with a stem. I think this would be a useful variation of the function. It shouldn't be hard to automate: (ly:grob-object grob 'stems) will get you an array of the stem grobs associated with the beam, and you could select a particular stem from the array with ly:grob-array-ref.
I did as you suggested (perhaps it could be shorter and more elegant, but it works :)). The argument of the function now aligns the peak with a stem. But you can also enter non-integer values: (grow-beam-var 3.5) centers the peak between the third and the fourth stem.
Looks great!
Values like "0" or values greater than the stem-count are faking \override Beam #'grow-direction = #LEFT (RIGHT). (This is not very elegant: switch on the color in \layout).
I'm not sure what I'm supposed to see here -- looks fine to me. (There must be a way to get around needing to give a non-existent "feather" a length of 0.001 to avoid division by zero, though, but my head gets a bit tangled up thinking about it!)
One little problem: With values between 0 and 1 (p.e. 0.5 or 0.8) I retrieve every time the same output. Well, no one would ever enter such strange values and perhaps I'm a little bit paranoic, but could it be, that there's a problem I can't see?
I think I solved this problem by changing the definition of the variable x-L. So now you can create all sorts of questionable subtleties (see image) :)
--David
harm-feathered-beams-align-to-stems.ly
example.png