Polyline sliders

[fmang]

I've stumbed upon a beatmap that used multi-segment linear sliders:
556757 fhana - RHAPSODY OF BLUE SKY (Sotarks) [Pentori's Hard]

Here's an example:
123,73,53738,2,0,L|126:43|129:13,1,47.9499985366822,8|8,0:0|0:0,0:0:0:0:

Sadly, the current implementation of the beatmap parser, and the geometry module, assume that linear segments were… linear, not polylinear. Crap.

Maybe the simplest solution is to drop linear sliders and only use Bézier paths, as the former is only a specialization of the latter, technically.