Re: polyphonic shorthand; line-spanner-interface in Hairpin

[Carl D. Sorensen]

On 3/17/09 3:48 PM, "Kieren MacMillan" <address@hidden>
wrote:

> Hi Carl,
> 
>> One issue that comes up in your proposal is that a 1/16 note column
>> does not
>> take up 1/16 of a whole note column.  So exactly what space are you
>> thinking
>> you want?
> 
> In the perfect scenario, I suppose Lilypond would "Do The Right Thing":
>     1. If there were another music event at the moment the Hairpin
> was set to begin (delayed) or end (trimmed), it would line up as
> expected.

So how about this as an explanation of DTRT?

Let's assume that the hairpin is a spanner (this much is correct, I think)
and that we know the musical length of the span (This is known because we
have the musical moment of the start and the musical moment of the end of
the hairpin.)

Then we define the delayed start moment as the start moment of the hairpin
plus the specified delay.

We define the trimmed end moment as the end moment of the hairpin minus the
specified trim amount.

Now I'm getting very iffy.   If there's a musical paper column at the
delayed start moment and the trimmed end moment, then we would want to shift
the spanner to those musical paper columns.

If not, then we have to adjust the size of the hairpin some other way, and
that's where things break down for me.  It may be a question of adjusting
springs and rods, but springs and rods are deep in the computational alchemy
of LilyPond, as far as I can see.

>     2. If there were no simultaneous music event, the Hairpin would
> begin/end proportionally between the immediately adjacent music events.
> 
>> Presently, dynamic markings are tied to paper columns.  Paper
>> columns are
>> created by layout objects, including notes.  It seems to me that
>> somehow you
>> want to change the way dynamic markings interact with paper columns
>> in order
>> to get the behavior you desire.
> 
> Probably... =(
> 
> I just think that dynamics are currently more difficult to manipulate
> than would be ideal, and I'm trying to come up with a solution.

Sure, and I'm trying to help you.  The problem is that padding operates by
adding horizontal space, rather than reducing horizontal extent.  What you
want to do is to reduce the horizontal extent of the hairpin, not add extra
space, I think.

I don't know how to handle this problem.  Perhaps Joe Neeman (the spacing
guru of LilyPond) can give you a pointer or two.

Carl