Re: Make sure slurs actually avoid stafflines. (issue 15400049)

[k-ohara5a5a]

https://codereview.appspot.com/15400049/diff/1/lily/slur-configuration.cc
File lily/slur-configuration.cc (left):

https://codereview.appspot.com/15400049/diff/1/lily/slur-configuration.cc#oldcode62
lily/slur-configuration.cc:62:
On 2013/10/23 04:22:23, Keith wrote:
> > but the function was broken: it only moved slurs in one direction

We concluded the same thing about the old code.  The old code intended
to move slurs in one direction only.

I was only confused by your comment. I interpreted 'broken' to mean
"failing to to what was intended".

https://codereview.appspot.com/15400049/diff/1/lily/slur-configuration.cc
File lily/slur-configuration.cc (right):

https://codereview.appspot.com/15400049/diff/1/lily/slur-configuration.cc#newcode60
lily/slur-configuration.cc:60: // rather than decrease, because we want
to avoid too flat slurs.
On 2013/10/23 21:41:24, janek wrote:

> Precisely because min_gap_above_staffline > min_gap_below_staffline
> we are more likely to increase than decrease curvature.

Okay.  So then the comment "The function is implemented so that we're
more likely to increase curvature" refers to the default values.

https://codereview.appspot.com/15400049/diff/1/lily/slur-configuration.cc#newcode84
lily/slur-configuration.cc:84: Real const slur_th = state.thickness_ *
staff_th * 10;
On 2013/10/23 21:41:24, janek wrote:
> On 2013/10/23 04:22:23, Keith wrote:
> > Why 10?  Is that the thickness of the fattest part of the slur?

> No, it's because staff_th is measured in staffspaces, while
state.thickness_
> appears to be measured in 1/10ths of staffline-thicknesses

state.thickness_ already has the \layout{line-thickness} as a factor in
its initialization in Slur_score_state::fill().

Staff_symbol_referencer::line_thickness() returns something that scales
with
\layout{line-thickness}

So, it looks like you have two factors of \layout{line-thickness} and
the *10 roughly cancels one of them.

https://codereview.appspot.com/15400049/