VoxeLibre/mods/ENVIRONMENT/mcl_weather/snow.lua

local get_connected_players = minetest.get_connected_players

mcl_weather.snow = {}

mcl_weather.snow.particles_count = 15
mcl_weather.snow.init_done = false

-- calculates coordinates and draw particles for snow weather 
mcl_weather.snow.add_snow_particles = function(player)
  mcl_weather.rain.last_rp_count = 0
  for i=mcl_weather.snow.particles_count, 1,-1 do
    local random_pos_x, random_pos_y, random_pos_z = mcl_weather.get_random_pos_by_player_look_dir(player)
    random_pos_y = math.random() + math.random(player:get_pos().y - 1, player:get_pos().y + 7)
    if minetest.get_node_light({x=random_pos_x, y=random_pos_y, z=random_pos_z}, 0.5) == 15 then
      mcl_weather.rain.last_rp_count = mcl_weather.rain.last_rp_count + 1
      minetest.add_particle({
        pos = {x=random_pos_x, y=random_pos_y, z=random_pos_z},
        velocity = {x = math.random(-100,100)*0.001, y = math.random(-300,-100)*0.004, z = math.random(-100,100)*0.001},
        acceleration = {x = 0, y=0, z = 0},
        expirationtime = 8.0,
        size = 1,
        collisiondetection = true,
        collision_removal = true,
        object_collision = false,
        vertical = false,
        texture = mcl_weather.snow.get_texture(),
        playername = player:get_player_name()
      })
    end
  end
end

mcl_weather.snow.set_sky_box = function()
  mcl_weather.skycolor.add_layer(
    "weather-pack-snow-sky",
    {{r=0, g=0, b=0},
    {r=85, g=86, b=86},
    {r=135, g=135, b=135},
    {r=85, g=86, b=86},
    {r=0, g=0, b=0}})
  mcl_weather.skycolor.active = true
  for _, player in pairs(get_connected_players()) do
    player:set_clouds({color="#ADADADE8"})
  end
  mcl_weather.skycolor.active = true
end

mcl_weather.snow.clear = function() 
  mcl_weather.skycolor.remove_layer("weather-pack-snow-sky")
  mcl_weather.snow.init_done = false
end

-- Simple random texture getter
mcl_weather.snow.get_texture = function()
  return "weather_pack_snow_snowflake"..math.random(1,2)..".png"
end

local timer = 0
minetest.register_globalstep(function(dtime)
  if mcl_weather.state ~= "snow" then 
    return false
  end
  
  timer = timer + dtime;
  if timer >= 0.5 then
    timer = 0
  else
    return
  end

  if mcl_weather.snow.init_done == false then
    mcl_weather.snow.set_sky_box()
    mcl_weather.snow.init_done = true
  end

  for _, player in pairs(get_connected_players()) do
    if (mcl_weather.is_underwater(player) or not mcl_worlds.has_weather(player:get_pos())) then
      return false
    end
    mcl_weather.snow.add_snow_particles(player)
  end
end)

-- register snow weather
if mcl_weather.reg_weathers.snow == nil then
	mcl_weather.reg_weathers.snow = {
		clear = mcl_weather.snow.clear,
		light_factor = 0.6,
		-- 10min - 20min
		min_duration = 600,
		max_duration = 1200,
		transitions = {
			[65] = "none",
			[80] = "rain",
			[100] = "thunder",
		}
	}
end