Re: Fixes slope errors from incorrect X extents in Beam::print. (issue 5293060)

[Keith OHara]

On Thu, 27 Oct 2011 01:34:00 -0700, address@hidden <address@hidden> wrote:

> > What about the x_span_ of the Beam_scoring_problem ?
>
> It represents two things at two different stages of Beam_scoring_problem.

Too bad you didn't use two different variables.

> Starting at update_x_span_after_extremal_hangover_compensation (), the x_span_
> becomes the real span of the beam, tacking on left and right overhang that may
> come from stemlets or broken beams.  This is necessary for the quanting (we
> always want edges quanted) but not possible for the slope calculations, which
> are predicated on the idea that unquanted_y_ represents the beginning and end
> of the beam (otherwise, we'd have to compensate for extremal hangover in each
> function).

You are telling me _what_ happens, which I could see from the code.  Some things
looked strange, possibly accidental, so I wanted to know _why_.

I see that the slope-determining steps are influenced by note-heads, so the
interval with normal stems is _slightly_ more convenient to use there.  I notice
that least_squares_positions() has a comment wishing it could see the note-heads
on the other portion(s) of a broken beam, for exactly your purposes.

The interface through \override Beam 'positions used to control heights at the
positions of the first- and last- normal stems, but that wasn't documented --
or very convenient in case of overhangs.

You make a good point that quanting should work with the ends of the full beam
as printed including overhangs, but I assume that change is a separate commit.


> > The difference between
> > consistent_broken_slope_ and consistent_broken_slope is dangerous all by
> > itself.
>
> I'm not sure what you mean - how is this dangerous?
Similar names (formerly also similar to the property 'consistent-broken-slope)
with different values. Only dangerous if someone changing the code later is
un-careful about distinguishing them.  The new patch is better about this.