isPointInside clarification about geolib HOT 3 CLOSED

Let's assume the coordinate you want to check is (8,10) and the coordinates you want to check it against are A(2,2), B(2,12), C(18,12) and D(18,2). Then (8,10) is within your polygon.

If you change the order of your coordinates you will get a different result. I made a small illustration because … a picture is worth a thousand words ;)

"right" order

"wrong" order

geolib.isPointInside([8, 10], [
  [2,2], [2,12], [18,12], [18,2]
]);

-> true

Same coordinates but different order (C and D flipped):

geolib.isPointInside([8, 10], [
  [2,2], [2,12], [18,2], [18,12]
]);

-> false

from geolib.

Ok thanks that makes sense! You pictures are great! a 1000 words indeed.

from geolib.

What if I provide coordinates for 2 polygons?

from geolib.