Gets the beam collision engraver to handle autobeams

Gets the beam collision engraver to handle autobeams

intermediary

[MikeSol, 2011-03-19 22:50:41]

This is my attempt to get the beam-collision-engraver to handle auto beams,
except...it doesn't work!  For some reason, in spite of the fact that I'm
creating AutoBeamStub grobs just fine, the acknowledger in the beam collision
engraver is not picking them up.  Can anyone suggest where the system is broken?

Cheers,
Mike

[MikeSol, 2011-03-20 12:00:34]

This is now fully functional.
The only issue is that, for auto-beams, I don't have a good method yet for
keeping note-heads that are part of the beam out of the covered grobs list. 
This is doable, though - I just have to think of the cleanest way.

[Neil Puttock, 2011-03-22 23:22:20]

On 2011/03/20 12:00:34, MikeSol wrote:
> This is now fully functional.
> The only issue is that, for auto-beams, I don't have a good method yet for
> keeping note-heads that are part of the beam out of the covered grobs list. 
> This is doable, though - I just have to think of the cleanest way.

Before you attempt that, can you think of a cleaner way to implement the basic
functionality which doesn't involve creating a dummy grob?

Cheers,
Neil

[mike_apollinemike.com, 2011-03-23 10:30:15]

On Mar 22, 2011, at 7:22 PM, n.puttock@gmail.com wrote:

> On 2011/03/20 12:00:34, MikeSol wrote:
>> This is now fully functional.
>> The only issue is that, for auto-beams, I don't have a good method yet
> for
>> keeping note-heads that are part of the beam out of the covered grobs
> list.
>> This is doable, though - I just have to think of the cleanest way.
> 
> Before you attempt that, can you think of a cleaner way to implement the
> basic functionality which doesn't involve creating a dummy grob?
> 
> Cheers,
> Neil

OK, idea:

In the auto beam engraver, every time a beam is created, a variable called
timestep_ticker_ gets reset to 0 and increments by +1 for every timestep passed
until the beam is completed (or junked if the beam is junked).  This is stashed
as an internal property called "timesteps-spanned."

Then, in the beam collision engraver, there is a vector<vector<Grob *> *> called
covered_grobs_queue_ that stores vectors of all acknowledged grobs (clefs,
note-heads, accidentals, etc.) for a given timestep (with an empty vector being
assigned for a acknowledged-grobless timestep).  This vector is cleared at every
barline (w/ appropriate deletes for the pointers to vectors).  When an autobeam
is completed (which we'll know because it will be announced during the same
timestep as its end-grob), we look at the property timesteps-spanned and iterate
through covered_grobs_queue_ starting from covered_grobs_queue_.size () -
timesteps_spanned to the end, adding its contents to the grob array
covered-grobs.

Does this seem like a good idea?  It'd need some tweaking to deal w/ covered
interior grobs & to avoid code dups, but I think it's clean.

Cheers,
Mike