markdown 从另一个图层的边界框创建一个十六进制网格

Posted 2021-05-05

function hexGridFromLayerBBox(
  bboxJson,
  cellSide = 1,
  hexUnits = "miles",
  radius = 0,
  bufferUnits = "miles"
) {
  // requires turfjs
  let bbox = turf.bbox(
    turf.buffer(bboxJson, radius, {
      units: bufferUnits
    })
  );

  return turf.hexGrid(bbox, cellSide, {
    unit: hexUnits
  });
}

This function takes an input GeoJSON dataset and creates a generates a hex grid from the bounding box of that layer. Because of the way hex grids are created using turfjs, using the bounding box doesn't necessarily result in every area of the input GeoJSON being covered by a hex grid. As such you can also set buffer parameters, `radius` and `bufferUnits`, to expand the area for which the bounding box is created. You can define the size of the hexagons with the `cellSide` and `hexUnits` parameters.