surface.total_pollution read

[Boodals]

Currently, to get the total amount of pollution on a surface, you have to iterate over every chunk, and call get_pollution on them all. As surfaces can easily have hundreds if not thousands of chunks, it quickly gets slow.

Bilka said on discord that the game tracks polluted chunks, and thus will be able to do it more efficiently. Also less API calls is always better.

[Rseding91]

What's the use-case? I could add it, but it's still an O(N) cost where N is all of the polluted chunks.

[darkfrei]

What's the use-case? I could add it, but it's still an O(N) cost where N is all of the polluted chunks.

How it was checked in evolution calculation?

[Godmave]

How it was checked in evolution calculation?

I would guess that that one only sums up the pollution absorbed by the spawners

[DaveMcW]

Evolution only adds up pollution, it doesn't subtract when it is absorbed by tiles.

[Rseding91]

What's the use-case? I could add it, but it's still an O(N) cost where N is all of the polluted chunks.

How it was checked in evolution calculation?

Evolution is modified as pollution is created.

[Mylon]

It's pretty simple to do in lua:

Code: Select all

function getPollution()
	-- Iterate over all chunks and sum pollution.
		local pollution = 0
		-- local surface = game.surfaces[1]
		for chunk in game.surfaces[1].get_chunks() do
			pollution = pollution + game.surfaces[1].get_pollution({chunk.x*32, chunk.y*32})
		end
		return pollution
end

[Boodals]

What's the use-case? I could add it, but it's still an O(N) cost where N is all of the polluted chunks.

A simple use case would be just a GUI that monitors the total amount of pollution your factory is producing.
My use case is: a mod which makes pollution affect whether the surface is habitable, or if you need a special suit to breathe, and also causes global warming which can melt ice (alien biomes), and start forest fires.

As an alternative to the O(N), you could keep a running total for each surface that updates when pollution is created/absorbed. It would affect performance of the base game, but perhaps it could be used in a graph. It would be nice to be able to see how much less pollution you're producing by installing efficiency modules, for example.

It's pretty simple to do in lua:

Read the OP

[Boodals]

Ayy I implemented this myself for 0.17 (I got access to the game's source code).
LuaSurface.get_total_pollution()