Dirt transformation

Changed the ABM that converts dirt into lawn
Now it detects the climate and changes the dirt accordingly
Added setting dry_dirt_threshold that is the highest humidity on which the dirt is converted to dry lawn.

mapgen.lua

@@ -119,6 +119,7 @@ local average_stone_level = vmg.define("average_stone_level", 180)
 local dirt_reduction = math.sqrt(average_stone_level) / (vmg.noises[7].offset - 0.5) -- Calculate dirt_reduction such as v7 - sqrt(average_stone_level) / dirt_reduction = 0.5 on average. This means that, on average at y = average_stone_level, dirt_thickness = 0.5 (half of the surface is bare stone)
 local average_snow_level = vmg.define("average_snow_level", 100)
 local snow_threshold = vmg.noises[17].offset * 0.5 ^ (average_snow_level / altitude_chill)
+local dry_dirt_threshold = vmg.define("dry_dirt_threshold", 0.6)
 
 local player_max_distance = vmg.define("player_max_distance", 450)
 
@@ -662,6 +663,10 @@ function vmg.get_humidity(pos)
 	return soil_humidity * (1 + water)
 end
 
+function vmg.test_dry(pos)
+	return vmg.get_humidity(pos) <= dry_dirt_threshold
+end
+
 function vmg.get_temperature(pos)
 	local v12 = vmg.get_noise(pos, 12) + 1 -- Lava noise for underground
 	local v17 = vmg.get_noise(pos, 17) -- Climate noise
@@ -673,6 +678,10 @@ function vmg.get_temperature(pos)
 	end
 end
 
+function vmg.test_snow(pos)
+	return vmg.get_temperature(pos) <= snow_threshold
+end
+
 function vmg.get_noise(pos, i)
 	local n = vmg.noises[i]
 	local noise = minetest.get_perlin(n.seed, n.octaves, n.persist, 1)

nodes.lua

@@ -85,6 +85,8 @@ local function register_dirts(readname)
 		}),
 	})
 
+
+
 	minetest.register_abm({
 		nodenames = {itemstr_dirt},
 		interval = 2,
@@ -96,8 +98,10 @@ local function register_dirts(readname)
 			if nodedef and (nodedef.sunlight_propagates or nodedef.paramtype == "light")
 					and nodedef.liquidtype == "none"
 					and (minetest.get_node_light(above) or 0) >= 13 then
-				if name == "default:snow" or name == "default:snowblock" then
+				if name == "default:snow" or name == "default:snowblock" or (vmg.test_snow and vmg.test_snow(pos)) then
 					minetest.set_node(pos, {name = itemstr_snow})
+				elseif vmg.test_dry and vmg.test_dry(pos) then
+					minetest.set_node(pos, {name = itemstr_dry})
 				else
 					minetest.set_node(pos, {name = itemstr_lawn})
 				end
@@ -106,7 +110,7 @@ local function register_dirts(readname)
 	})
 
 	minetest.register_abm({
-		nodenames = {itemstr_lawn},
+		nodenames = {itemstr_lawn, itemstr_dry},
 		interval = 2,
 		chance = 20,
 		action = function(pos, node)

settingtypes.txt

@@ -75,6 +75,9 @@ vmg_dirt_threshold (Normal dirt threshold) float 0.5
 #    height at which the half of the surface is covered by snow.
 vmg_average_snow_level (Average snow level) int 100
 
+#    if humidity is below this value, make dry dirt instead of lawn
+vmg_dry_dirt_threshold (Dry dirt threshold) float 0.6
+
 [*Rivers]
 #    Simply the depth of the rivers
 vmg_river_depth (River depth) int 3