Support expanding polygons by moving each its segment `d` towards the outer normal

[disberd]

Expanding polygons is probably best done expanding each segment towards the direction of its outer normal (the normal towards the OUTSIDE of the polygon) by a given length/distance d.

See this link for some reference: https://stackoverflow.com/questions/54033808/how-to-offset-polygon-edges

And this other for more complex scenarios which might be worth considering in the future: https://stackoverflow.com/questions/1109536/an-algorithm-for-inflating-deflating-offsetting-buffering-polygons

[mcontim]

• Neither expanding nor reducing the size of a polygon is a trivial operation, for the moment Clipper.jl can be used as inital implementation before going for a full Julia solution. Look here and here for more details on the implementation in Clipper C++.
• Julia packages like LazySets.jl give some mathematical tools to tackle the problem (see Bloating).
• In mathematical terms, the problem can be refferred as polygon offsetting and refers to the process of creating parallel curves
• This problem can be tackled with Minkowski sum for "dilation" of the polygon and Minkovski erosion or subtraction for the "shrinking" of the polygon.
• The next step could be contributing to Meshes.jl for realizing a full Julia solution, eiteher a porting of Clipper2 or a completely new implementation (maybe starting from the mathematical tools given by other libraries like LazySets.jl)