Use concaveman!

[tmcw]

@mourner made concaveman - let's use it!

[mourner]

I'd be happy to see it used here, as it's orders of magnitude faster. It should be noted though that there are disadvantages too:

• there are two tuning parameters (concavity and lengthThreshold) that are both not very intuitive, so we would have to make the API less straightforward or settle on some defaults
• the output may be less "optimal" because it's not based on Delaunay triangulation, although I'm not sure — needs some comparisons

[kelvinabrokwa]

@mourner @morganherlocker it looks like concaveman doesn't behave in the same way that the current implementation does. For example, it never creates islands (multipolygons) whereas turf-concave, under certain conditions, will.

@morganherlocker also tells me this is not a thing in turf ⬇️

[tmcw]

Implemented in https://github.com/Turfjs/turf