should disable falling snow in deserts

src/falling_snow.lua

@@ -40,24 +40,26 @@ near torches and lava.
 --=============================================================
 
 
-if snow.enable_snowfall then
+if not snow.enable_snowfall then
+	return
+end
 
-	local weather_legacy
+local weather_legacy
 
-	local read_weather_legacy = function ()
+local read_weather_legacy = function ()
 	local file = io.open(minetest.get_worldpath().."/weather_v6", "r")
 	if not file then return end
 	local readweather = file:read()
 	file:close()
 	return readweather
-	end
+end
 
-	--Weather for legacy versions of minetest.
+--Weather for legacy versions of minetest.
-	local save_weather_legacy = function ()
+local save_weather_legacy = function ()
 	local file = io.open(minetest.get_worldpath().."/weather_v6", "w+")
 	file:write(weather_legacy)
 	file:close()
-	end
+end
 
 	weather_legacy = read_weather_legacy() or ""
 
@@ -75,25 +77,36 @@ if snow.enable_snowfall then
 		end
 	end)
 
-	--Get snow at position.
+-- copied from meru mod
-	local get_snow = function(pos)
+local SEEDDIFF3 = 9130 -- 9130 -- Values should match minetest mapgen desert perlin.
+local OCTAVES3 = 3 -- 3
+local PERSISTENCE3 = 0.5 -- 0.5
+local SCALE3 = 250 -- 250
+
+--Get snow at position.
+local get_snow = function(pos)
 	--Legacy support.
 	if weather_legacy == "snow" then
-			local perlin1 = minetest.env:get_perlin(112,3, 0.5, 150)
+		local perlin1 = minetest.get_perlin(112,3, 0.5, 150)
-			if perlin1:get2d( {x=pos.x, y=pos.z} ) > 0.53 then
+		if perlin1:get2d({x=pos.x, y=pos.z}) <= 0.53 then
+			return false
+		end
+
+		-- disable falling snow in desert
+		local desert_perlin = minetest.get_perlin(SEEDDIFF3, OCTAVES3, PERSISTENCE3, SCALE3)
+		local noise3 = desert_perlin:get2d({x=x+150,y=z+50}) -- Offsets must match minetest mapgen desert perlin.
+		if noise3 > 0.35 then -- Smooth transition 0.35 to 0.45.
+			return false
+		end
 		return true
-			else
+	end
 	return false
-			end
+end
-		else
-			return false
-		end
-	end
 
-	local addvectors = vector and vector.add
+local addvectors = vector and vector.add
 
-	--Returns a random position between minp and maxp.
+--Returns a random position between minp and maxp.
-	local randpos = function (minp, maxp)
+local randpos = function (minp, maxp)
 	local x,y,z
 	if minp.x > maxp.x then
 		x = math.random(maxp.x,minp.x) else x = math.random(minp.x,maxp.x) end
@@ -101,18 +114,18 @@ if snow.enable_snowfall then
 	if minp.z > maxp.z then
 		z = math.random(maxp.z,minp.z) else z = math.random(minp.z,maxp.z) end
 	return {x=x,y=y,z=z}
-	end
+end
 
-	local default_snow_particle = {
+local default_snow_particle = {
 	amount = 3,
 	time = 0.5,
 	exptime = 5,
 	size = 50,
 	collisiondetection = false,
 	vertical = false,
-	}
+}
 
-	local function get_snow_particledef(data)
+local function get_snow_particledef(data)
 	for n,i in pairs(default_snow_particle) do
 		data[n] = data[n] or i
 	end
@@ -122,18 +135,18 @@ if snow.enable_snowfall then
 	end
 	data.texture = "weather_snow.png^[transform"..math.random(0,7)
 	return data
-	end
+end
 
-	local snow_fall=function (pos, player, animate)
+local function snow_fall(pos, player, animate)
 	local ground_y = nil
 	for y=pos.y+10,pos.y+20,1 do
-				local n = minetest.env:get_node({x=pos.x,y=y,z=pos.z}).name
+		local n = minetest.get_node({x=pos.x,y=y,z=pos.z}).name
 		if n ~= "air" and n ~= "ignore" then
 			return
 		end
 	end
 	for y=pos.y+10,pos.y-15,-1 do
-				local n = minetest.env:get_node({x=pos.x,y=y,z=pos.z}).name
+		local n = minetest.get_node({x=pos.x,y=y,z=pos.z}).name
 		if n ~= "air" and n ~= "ignore" then
 			ground_y = y
 			break
@@ -161,10 +174,10 @@ if snow.enable_snowfall then
 		snow.place(pos, true)
 		--minetest.place_node({x=pos.x, y=pos.y+2, z=pos.z}, {name="default:snow"}) -- LazyJ
 	end
-	end
+end
 
-	-- Snow
+-- Snow
-	minetest.register_globalstep(function(dtime)
+minetest.register_globalstep(function(dtime)
 	for _, player in pairs(minetest.get_connected_players()) do
 		local ppos = player:getpos()
 		
@@ -172,7 +185,7 @@ if snow.enable_snowfall then
 		local smaxp = addvectors(ppos, {x= 20, y=0, z= 20})
 	
 		-- Make sure player is not in a cave/house...
-			if get_snow(ppos) and minetest.env:get_node_light(ppos, 0.5) == 15 then
+		if get_snow(ppos) and minetest.get_node_light(ppos, 0.5) == 15 then
 
 			local minp = addvectors(ppos, {x=-9, y=3, z=-9})
 			local maxp = addvectors(ppos, {x= 9, y=5, z= 9})
@@ -213,15 +226,6 @@ if snow.enable_snowfall then
 					snow_fall(randpos(sminp, smaxp), player, true)
 				end
 			end
-					
-				
-			else
-			
-				if math.random(1,5) == 4 then	
-					snow_fall(randpos(sminp, smaxp), player, true)
 		end
 	end
-		end
+end)
-	end)
-	
-end