Re: 2.12.21 regtests

[address@hidden]

Le Dec 9, 2011 à 3:19 PM, David Kastrup a écrit :

> The changes you are doing operate in the pure spacing domain, yet they
> don't get accounted for in line breaking.  Right or wrong?
> 

All of the pure-from-neighbor changes take place before line breaking happens.  
They change the distances of the springs, and thus they are taken into account 
in line breaking.

> So your local improvements in horizontal spacing are done at the cost of
> suboptimal spacing distributed over the whole line.  Right or wrong?

I still don't see what you mean - could you give me a .ly example of what this 
would look like?

> The larger the local improvements are, the larger the line-wide
> detriments become.  Right or wrong?

Here is an example with huge local improvements.  The first is default 
behavior, the second recreates behavior from before the pure-from-neighbor 
stuff.

{
  \repeat unfold 3 {
    \time 3/4 <cis'''' c''''! dis'''' d''''! eis'''' e''''!> g' g'
    \time 4/4 <cis'''' c''''! dis'''' d''''! eis'''' e''''!> g' g' g'
  }
}

{
  \override Staff . TimeSignature #'extra-spacing-height = #'(0 . 0)
  \repeat unfold 3 {
    \time 3/4 <cis'''' c''''! dis'''' d''''! eis'''' e''''!> g' g'
    \time 4/4 <cis'''' c''''! dis'''' d''''! eis'''' e''''!> g' g' g'
  }
}

This is a large local improvement, but I don't see how it leads to detriments 
on the whole.


> 
> If you manage really large local improvements in a complex piece by
> being able to tuck a lot of material nicely, the filling of the line
> will become quite suboptimal.
> 
> That's the "worse overall".  The more local improvements you do
> bypassing the global optimization, the further the whole-line results
> become from being optimal.  More often than not, the local improvements
> will be better than the global detriment, but the global detriment is
> not necessary if you manage to cast the local improvements in a form
> where they don't bypass the global optimization.

I fail to see how this bypasses the global optimization.  Global optimization 
takes place in constrained-breaking.cc when the spring and rod problems are 
solved.  All of these things happen after the pure heights are calculated.  
Where is the bypass?

Cheers,
MS