Implement API to disable weather

mods/weather/init.lua

@@ -1,21 +1,12 @@
--- Disable by mapgen or setting
-
+-- Check whether mod should be active
 local mg_name = minetest.get_mapgen_setting("mg_name")
-if minetest.settings:get_bool("enable_weather") == false then
-	return
-end
+local mod_enabled = minetest.settings:get_bool("enable_weather", true)
+local randomize_clouds = mod_enabled and mg_name ~= "v6" and mg_name ~= "singlenode"
 
-if mg_name == "v6" or mg_name == "singlenode" then
-	-- set a default shadow intensity for mgv6 and singlenode
-	minetest.register_on_joinplayer(function(player)
-		player:set_lighting({ shadows = { intensity = 0.33 } })
-	end)
-
-	return
-end
+weather = {}
+local playerlist = {}
 
 -- Parameters
-
 local TSCALE = 600 -- Time scale of noise variation in seconds
 local CYCLE = 8 -- Time period of cyclic clouds update in seconds
 
@@ -61,7 +52,6 @@ local np_speedz = {
 
 -- End parameters
 
-
 -- Initialise noise objects to nil
 
 local nobj_density = nil
@@ -69,7 +59,6 @@ local nobj_thickness = nil
 local nobj_speedx = nil
 local nobj_speedz = nil
 
-
 -- Update clouds function
 
 local function rangelim(value, lower, upper)
@@ -79,7 +68,7 @@ end
 local os_time_0 = os.time()
 local t_offset = math.random(0, 300000)
 
-local function update_clouds()
+local function update_clouds(players)
 	-- Time in seconds.
 	-- Add random time offset to avoid identical behaviour each server session.
 	local time = os.difftime(os.time(), os_time_0) - t_offset
@@ -94,7 +83,7 @@ local function update_clouds()
 	local n_speedx = nobj_speedx:get_2d({x = time, y = 0}) -- -1 to 1
 	local n_speedz = nobj_speedz:get_2d({x = time, y = 0}) -- -1 to 1
 
-	for _, player in ipairs(minetest.get_connected_players()) do
+	for _, player in ipairs(players) do
 		-- Fallback to mid-value 50 for very old worlds
 		local humid = minetest.get_humidity(player:get_pos()) or 50
 		-- Default and classic density value is 0.4, make this happen
@@ -114,22 +103,93 @@ local function update_clouds()
 			speed = {x = n_speedx * 4, z = n_speedz * 4},
 		})
 		-- now adjust the shadow intensity
-		player:set_lighting({ shadows = { intensity = 0.7 * (1 - density) } })
+		player:set_lighting({
+			shadows = { intensity = 0.7 * (1 - density) }
+		})
 	end
 end
 
-
-local function cyclic_update()
-	update_clouds()
-	minetest.after(CYCLE, cyclic_update)
+local function purge_effects(player)
+	-- reset potentially touched values to their defaults
+	if randomize_clouds then
+		player:set_clouds({
+			density = 0.4,
+			thickness = 16,
+			speed = { x = 0, z = -2 }
+		})
+	end
+	player:set_lighting({
+		shadows = { intensity = 0 }
+	})
 end
 
+-- Define API hooks
 
-minetest.after(0, cyclic_update)
+-- override to set state for newly joined players
+weather.enable_on_join = true
 
+-- returns bool for whether weather is active
+-- returns nil if player is offline or weather is disabled
+weather.get_enabled = function(player)
+	return playerlist[player]
+end
+
+-- override weather generation for individual player
+weather.set_enabled = function(player, enable)
+	if enable == playerlist[player] then
+		return
+	end
+	playerlist[player] = enable
+	if enable then
+		if randomize_clouds then
+			update_clouds({player})
+		end
+	else
+		purge_effects(player)
+	end
+end
+
+-- End API hooks
+
+-- skip event registration if mod is disabled
+if not mod_enabled then
+	return
+end
+
+if update_clouds then
+	local function cyclic_update()
+		local players = {}
+		for player, state in pairs(playerlist) do
+			if state then
+				table.insert(players, player)
+			end
+		end
+		update_clouds(players)
+		minetest.after(CYCLE, cyclic_update)
+	end
+	minetest.after(0, cyclic_update)
+end
 
 -- Update on player join to instantly alter clouds from the default
 
 minetest.register_on_joinplayer(function(player)
-	update_clouds()
+	if weather.enable_on_join then
+		playerlist[player] = true
+		if randomize_clouds then
+			update_clouds({player})
+		else
+			-- set a default shadow intensity for mgv6 and singlenode
+			player:set_lighting({
+				shadows = {
+					intensity = 0.33
+				}
+			})
+		end
+	else
+		playerlist[player] = false
+	end
+end)
+
+minetest.register_on_leaveplayer(function(player)
+	table.remove(player)
 end)