Cut operation - right vs. left

[DavidHollman]

In the documentation on this page: http://esri.github.io/geometry-api-java/doc/Cut.html

It says:

"All left cuts will be grouped together in the first geometry. Right cuts and coincident cuts are grouped in the second geometry."

What do left and right mean in this context?

Thanks

[jgravois]

i could be wrong, but i always assumed right and left referred to the cardinality as perceived using the bearing of the cutting geometry if it were to animate and grow dynamically from its first vertex to its last to do the cutting.

[stolstov]

At the location of the cut, the left is to the left of the tangent vector of the the cutter segment and the right is to the right of it. For the tangent vector if you direct your right hand index finger in the direction of the tangent your thumb will point to the left (keep your palm faced down to the 2D plane).

[jgravois]

reference: https://en.wikipedia.org/wiki/Right-hand_rule

[DavidHollman]

Thanks for the clarifications. IMO this would be good info to expand on in the Wiki page. The detail that a polyline has a direction was not evident to a newbie like me. Also I had missed the distinction that the CUT operation's second argument is a polyline, wheras most others take a GEOMETRY.

[jgravois]

we actually host that document in the gh-pages branch of this repository. a pull request with the improvements you mentioned would be welcome.

https://github.com/Esri/geometry-api-java/blob/f30ffabb54f0d3753695c39da83e713dd8ba5833/doc/Cut.html#L55-L58