Hole near to the border returns self intersection about sweepline-intersections HOT 3 CLOSED

Hi @Falke-Design

I'm not sure if I've got the best answer but I think this might be a projection issue.

If you modify the map to display the data in a non-projected manner using L.CRS.Simple then you don't see any little gaps.

var map = L.map('map', {
	crs: L.CRS.Simple,
	center: [0, 0],
	zoom: 3,
	maxZoom: 20
});

Thinking about it mathematically I would also expect an intersection point at [0.5, -0.5] on a segment between [0, 0], [1, -1].

So I think this is one of those quirks when data is presented when with projections.

Make sense?

from sweepline-intersections.

Yeah I understand ... 😕 I think it would be to much work to include a CRS option?

from sweepline-intersections.

So if you run the analysis with the coords in WebMercator then no intersections will be returned, as per what you're expecting visually.
I don't think it's this libraries job to project coordinates for you, you're better off using proj4 or @turf/projection for that.

eg

{
  "type": "MultiPolygon",
  "coordinates": [
    [
      [
        [
          0.0,
          0.0
        ],
        [
          111319.490793273565941,
          -111325.142866385082016
        ],
        [
          222638.981586547131883,
          222684.208505544025684
        ],
        [
          0.0,
          0.0
        ]
      ],
      [
        [
          33395.847237982066872,
          33395.999833380206837
        ],
        [
          66791.694475964133744,
          66792.915264250957989
        ],
        [
          55659.745396636782971,
          -55660.451865421520779
        ],
        [
          33395.847237982066872,
          33395.999833380206837
        ]
      ]
    ]
  ]
}

from sweepline-intersections.