not detecting intersections in this case.

[tanmoyAtb]

The algorithm did not detect intersections in the following coordinates of a polygon.

const box = {
  type: "Polygon",
  coordinates: [
    [
      [90.39974817514972, 23.873991637113175],
      [90.40572498813789, 23.872911671285607],
      [90.40575223587952, 23.874804784092955],
      [90.4053503301788, 23.875873772177464],
      [90.40030947983682, 23.87861920694433],
      [90.39621276706808, 23.878127145947108],
      [90.3921160542993, 23.87747811375598],
      [90.39023118436477, 23.882439106594358],
      [90.38922437638114, 23.88382080428333],
      [90.38693010807042, 23.88390756033242],
      [90.38277413010324, 23.877399629023042],
      [90.37991123348131, 23.875909945040224],
      [90.37897952735014, 23.873517645288647],
      [90.37864863603832, 23.871792452376454],
      [90.37969103574207, 23.869125362621826],
      [90.3834212654788, 23.86583190806136],
      [90.38663651108469, 23.86556034446246],
      [90.39203703403477, 23.865488168279917],
      [90.3940094372637, 23.865251113185526],
      [90.3959818404927, 23.86548501039226],
      [90.39992664695066, 23.865638836372778],
      [90.40017732859211, 23.874030880518813],
      [90.39974817514972, 23.873991637113175],
      [90.39974817514972, 23.873991637113175],
      [90.39974817514972, 23.873991637113175],
    ],
  ],
};

It is a geoJSON coordinate list, the screenshot from geoJSON.io (Maybe the intersection only happens in spherical surfaces)

[rowanwins]

Hi @tanmoyAtb

I'd recommend checking out my sweepline-intersections library, it detects the intersection. The sweepline-intersections library has a slightly different API and returns all the intersections points, rather than just a boolean when the first self-intersection is discovered.

I'd need to look more closely as to why this case is failing in this lib, but passing in the other, because they use a fair bit of the same logic for the actual segment-to-segment intersection check. I suspect it's because the queueing logic is more complex in this library and it's not running a check on those overlapping segments.

Cheers