How to convert between different formats?

[Pflyg]

I wanted to use FlattenJS for just it's polygon boolean operations (since I already have implemented other functionality otherwise) and for that want to convert my polygon format into FlattenJS format.
For that I use the following function: return Flatten.polygon(this.points.map(p => Flatten.point(p.x, p.y)));
this.points is an array of points Point: {x, y}. For a hexagon I would have 6 points at the corners for example.This actually works fine.

But when I want to convert the result of a boolean intersection back the polygon seems to be intersecting itself (even though .isValid returns true). This is the function I use to convert them back:
var points = intersection.vertices.map(p => new Point(p.x, p.y))
new Point is the same type I used above.
It seems like the vertices of flattenJs seem to be a bit more complicated. How would I go about converting them to just an array of points, each point being connected to the next one?