Interpolated pollution display on map

[immibis]

Right now the map's pollution display is noticeably blocky, as pollution is tracked per map chunk. I suggest it should be interpolated, so that the pollution strength of a chunk is shown at the centre of the chunk, and in between chunk centres is a gradient.

[Coolthulhu]

I don't like the idea of displaying a gradient when the actual data is clearly discrete.
Early game it's rather important whether your slight pollution gets absorbed by a bunch of trees or a spawner behind them. The chunks should be clearly visible for as long as they're used in calculations.