Re: Gets vertical skylines from grob stencils (issue 5626052)

[address@hidden]

Hey all,

I've uploaded a first-pass attempt at implementing the suggestion that Joe 
talked about (using buildings directly in the skylines).
This saves a lot of time in the calculation of skyline distance (time spent in 
Axis_group_interface::skyline_spacing can go from 2 to 0.2 seconds for scores 
with lots of beams and hairpins).

However, the global time takes a huge hike with this patchset because skylines 
are constantly being rebuilt with padding added on.  I'm going to re-look at 
all of the code and see where it is safe to just include padding when the 
skyline is built.  This'll bring the compilation times back down - I'll likely 
have it done in the next few days (by Monday-ish).

In the meantime, I'm noticing that using buildings to approximate lines only 
saves time for line segments of a certain length.  Otherwise, it actually slows 
things down.  I'll try to build this distinction into stencil-integral.cc.

Cheers,
MS