[Tagging] editing polygons in JOSM

Christoph Hormann chris_hormann at gmx.de
Tue May 27 20:19:55 UTC 2014

On Tuesday 27 May 2014, Peter Wendorff wrote:
> Cutting by a line is easy:
> - add a way with nodes for start and end of the line where it cut's
> the polygon first and last.
> - add nodes where that new way intersects the old polygon
> - split the new way at these nodes
> - split the old polygon at these nodes
> - delete the parts of the old polygon that is outside the new one
> - combine polygon and some of the new ways (parts of the one you
> drawed initially) where that should be done

I would not really call that easy.

JOSM could really use some basic boolean operation on polygons.  If you 
have a large multipolygon with like a hundred ways in it you want to 
cut in two for example this is quite cumbersome and error prone at the 

Christoph Hormann

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