geoshape with single point won't show

[mattijn]

The following Vega-lite code with a single point:

{
  "data": {
    "values": [
      {
        "type": "Feature",
        "geometry": {
          "type": "Point",
          "coordinates": [
            4.8885,
            52.4039
          ]
        }
      }    
    ]
  },
  "mark": {
    "type": "geoshape"
  }
}

renders empty:

But when there are two points:

{
  "data": {
    "values": [
      {
        "type": "Feature",
        "geometry": {
          "type": "Point",
          "coordinates": [
            4.8885,
            52.4039
          ]
        }
      },
      {
        "type": "Feature",
        "geometry": {
          "type": "Point",
          "coordinates": [
            5.8885,
            53.4039
          ]
        }
      }      
    ]
  },
  "mark": {
    "type": "geoshape"
  }
}

they will both render:

It seems there is no extent computation of a single point.

[jheer]

I think this traces down to a d3-geo issue? Vega uses D3's projection fitting methods.

var p = d3.geoMercator();
p.fitExtent(
  [[0,0],[500,500]],
  {"type": "Feature", "geometry": {"type": "Point", "coordinates": [4.8885, 52.4039]}}
);

p.scale() // Infinity
p.translate() // [-Infinity, Infinity]

If you specify custom projection parameters in the VL spec, the map should work with a single point.