I am wondering if there is a way, algorithm, tools, to create, from a geometry, another one that is the border with a certain thickness.
This looks quite feasible with square or very simple shape, but with complex polygon I am a bit lost.
I am using geotools to manipulate the geometries.
I tried to scale the geometry and intersect the original and the expanded one but this does not work when the anchor point of the scale is not in the right place and I cannot figure out get it nice with all kind of shape.
Looks fine to me with geotools: