Added Pollution Grading

config/pollution_grading.lua

@@ -0,0 +1,7 @@
+-- This controls how pollution is viewed on the map
+return {
+    reference_point = {x=0,y=0}, -- where pollution is read from
+    max_scalar = 0.5, -- the scale between true max and max
+    min_scalar = 0.17, -- the scale between the lowest max and min
+    update_delay = 15 -- time in minutes between view updates
+}

modules/addons/pollution-grading.lua

@@ -0,0 +1,13 @@
+local Event = require 'utils.event'
+local config = require 'config.pollution_grading'
+
+local delay = config.update_delay * 3600 -- convert from minutes to ticks
+Event.on_nth_tick(delay,function()
+    local surface = game.surfaces[1]
+    local true_max = surface.get_pollution(config.reference_point)
+    local max = true_max*config.max_scalar
+    local min = max*config.min_scalar
+    local settings = game.map_settings.pollution
+    settings.expected_max_per_chunk = max
+    settings.min_to_show_per_chunk = min
+end)