Returns the distance from point to the polygon's boundary, signed so that
points inside the polygon get a negative distance and points outside get a
positive one.
Parameters
vertices: readonlynumber[]
polygon vertices as a flat array [x0, y0, x1, y1, ...]
n: number
number of vertices to read from vertices
point: readonly[number,number]
the query point
Returns number
the signed distance (negative inside, positive outside)
Returns the distance from
pointto the polygon's boundary, signed so that points inside the polygon get a negative distance and points outside get a positive one.