mods/ENVIRONMENT/lightning/init.lua

   1 --[[
   2
   3 Copyright (C) 2016 - Auke Kok <sofar@foo-projects.org>
   4
   5 "lightning" is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as
   7 published by the Free Software Foundation; either version 2.1
   8 of the license, or (at your option) any later version.
   9
  10 --]]
  11
  12 local S = minetest.get_translator("lightning")
  13
  14 lightning = {}
  15
  16 lightning.interval_low = 17
  17 lightning.interval_high = 503
  18 lightning.range_h = 100
  19 lightning.range_v = 50
  20 lightning.size = 100
  21 -- disable this to stop lightning mod from striking
  22 lightning.auto = true
  23
  24 local rng = PcgRandom(32321123312123)
  25
  26 local ps = {}
  27 local ttl = -1
  28
  29 local revertsky = function(dtime)
  30         if ttl == 0 then
  31                 return
  32         end
  33         ttl = ttl - dtime
  34         if ttl > 0 then
  35                 return
  36         end
  37
  38         mcl_weather.skycolor.remove_layer("lightning")
  39
  40         ps = {}
  41 end
  42
  43 minetest.register_globalstep(revertsky)
  44
  45 -- select a random strike point, midpoint
  46 local function choose_pos(pos)
  47         if not pos then
  48                 local playerlist = minetest.get_connected_players()
  49                 local playercount = table.getn(playerlist)
  50
  51                 -- nobody on
  52                 if playercount == 0 then
  53                         return nil, nil
  54                 end
  55
  56                 local r = rng:next(1, playercount)
  57                 local randomplayer = playerlist[r]
  58                 pos = randomplayer:get_pos()
  59
  60                 -- avoid striking underground
  61                 if pos.y < -20 then
  62                         return nil, nil
  63                 end
  64
  65                 pos.x = math.floor(pos.x - (lightning.range_h / 2) + rng:next(1, lightning.range_h))
  66                 pos.y = pos.y + (lightning.range_v / 2)
  67                 pos.z = math.floor(pos.z - (lightning.range_h / 2) + rng:next(1, lightning.range_h))
  68         end
  69
  70         local b, pos2 = minetest.line_of_sight(pos, {x = pos.x, y = pos.y - lightning.range_v, z = pos.z}, 1)
  71
  72         -- nothing but air found
  73         if b then
  74                 return nil, nil
  75         end
  76
  77         local n = minetest.get_node({x = pos2.x, y = pos2.y - 1/2, z = pos2.z})
  78         if n.name == "air" or n.name == "ignore" then
  79                 return nil, nil
  80         end
  81
  82         return pos, pos2
  83 end
  84
  85 -- lightning strike API
  86 -- * pos: optional, if not given a random pos will be chosen
  87 -- * returns: bool - success if a strike happened
  88 lightning.strike = function(pos)
  89         if lightning.auto then
  90                 minetest.after(rng:next(lightning.interval_low, lightning.interval_high), lightning.strike)
  91         end
  92
  93         local pos2
  94         pos, pos2 = choose_pos(pos)
  95
  96         if not pos then
  97                 return false
  98         end
  99
 100         minetest.add_particlespawner({
 101                 amount = 1,
 102                 time = 0.2,
 103                 -- make it hit the top of a block exactly with the bottom
 104                 minpos = {x = pos2.x, y = pos2.y + (lightning.size / 2) + 1/2, z = pos2.z },
 105                 maxpos = {x = pos2.x, y = pos2.y + (lightning.size / 2) + 1/2, z = pos2.z },
 106                 minvel = {x = 0, y = 0, z = 0},
 107                 maxvel = {x = 0, y = 0, z = 0},
 108                 minacc = {x = 0, y = 0, z = 0},
 109                 maxacc = {x = 0, y = 0, z = 0},
 110                 minexptime = 0.2,
 111                 maxexptime = 0.2,
 112                 minsize = lightning.size * 10,
 113                 maxsize = lightning.size * 10,
 114                 collisiondetection = true,
 115                 vertical = true,
 116                 -- to make it appear hitting the node that will get set on fire, make sure
 117                 -- to make the texture lightning bolt hit exactly in the middle of the
 118                 -- texture (e.g. 127/128 on a 256x wide texture)
 119                 texture = "lightning_lightning_" .. rng:next(1,3) .. ".png",
 120                 glow = minetest.LIGHT_MAX,
 121         })
 122
 123         minetest.sound_play({ pos = pos, name = "lightning_thunder", gain = 10, max_hear_distance = 500 }, true)
 124
 125         -- damage nearby objects, transform mobs
 126         local objs = minetest.get_objects_inside_radius(pos2, 3.5)
 127         for o=1, #objs do
 128                 local obj = objs[o]
 129                 local lua = obj:get_luaentity()
 130                 if obj:is_player() then
 131                 -- Player damage
 132                         if minetest.get_modpath("mcl_death_messages") then
 133                                 mcl_death_messages.player_damage(obj, S("@1 was struck by lightning.", obj:get_player_name()))
 134                         end
 135                         obj:set_hp(obj:get_hp()-5, { type = "punch", from = "mod" })
 136                 -- Mobs
 137                 elseif lua and lua._cmi_is_mob then
 138                         -- pig → zombie pigman (no damage)
 139                         if lua.name == "mobs_mc:pig" then
 140                                 local rot = obj:get_yaw()
 141                                 obj:remove()
 142                                 obj = minetest.add_entity(pos2, "mobs_mc:pigman")
 143                                 obj:set_yaw(rot)
 144                         -- mooshroom: toggle color red/brown (no damage)
 145                         elseif lua.name == "mobs_mc:mooshroom" then
 146                                 if lua.base_texture[1] == "mobs_mc_mooshroom.png" then
 147                                         lua.base_texture = { "mobs_mc_mooshroom_brown.png", "mobs_mc_mushroom_brown.png" }
 148                                 else
 149                                         lua.base_texture = { "mobs_mc_mooshroom.png", "mobs_mc_mushroom_red.png" }
 150                                 end
 151                                 obj:set_properties({textures = lua.base_texture})
 152                         -- villager → witch (no damage)
 153                         elseif lua.name == "mobs_mc:villager" then
 154                         -- Witches are incomplete, this code is unused
 155                         -- TODO: Enable this code when witches are working.
 156                         --[[
 157                                 local rot = obj:get_yaw()
 158                                 obj:remove()
 159                                 obj = minetest.add_entity(pos2, "mobs_mc:witch")
 160                                 obj:set_yaw(rot)
 161                         ]]
 162                         -- TODO: creeper → charged creeper (no damage)
 163                         elseif lua.name == "mobs_mc:creeper" then
 164
 165                         -- Other mobs: Just damage
 166                         else
 167                                 obj:set_hp(obj:get_hp()-5, { type = "punch", from = "mod" })
 168                         end
 169                 end
 170         end
 171
 172         local playerlist = minetest.get_connected_players()
 173         for i = 1, #playerlist do
 174                 local player = playerlist[i]
 175                 local sky = {}
 176
 177                 sky.bgcolor, sky.type, sky.textures = player:get_sky()
 178
 179                 local name = player:get_player_name()
 180                 if ps[name] == nil then
 181                         ps[name] = {p = player, sky = sky}
 182                         mcl_weather.skycolor.add_layer("lightning", {{r=255,g=255,b=255}}, true)
 183                         mcl_weather.skycolor.active = true
 184                 end
 185         end
 186
 187         -- trigger revert of skybox
 188         ttl = 0.1
 189
 190         -- Events caused by the lightning strike: Fire, damage, mob transformations, rare skeleton spawn
 191
 192         pos2.y = pos2.y + 1/2
 193         local skeleton_lightning = false
 194         if rng:next(1,100) <= 3 then
 195                 skeleton_lightning = true
 196         end
 197         if minetest.get_item_group(minetest.get_node({x = pos2.x, y = pos2.y - 1, z = pos2.z}).name, "liquid") < 1 then
 198                 if minetest.get_node(pos2).name == "air" then
 199                         -- Low chance for a lightning to spawn skeleton horse + skeletons
 200                         if skeleton_lightning then
 201                                 minetest.add_entity(pos2, "mobs_mc:skeleton_horse")
 202
 203                                 local angle, posadd
 204                                 angle = math.random(0, math.pi*2)
 205                                 for i=1,3 do
 206                                         posadd = {x=math.cos(angle),y=0,z=math.sin(angle)}
 207                                         posadd = vector.normalize(posadd)
 208                                         local mob = minetest.add_entity(vector.add(pos2, posadd), "mobs_mc:skeleton")
 209                                         mob:set_yaw(angle-math.pi/2)
 210                                         angle = angle + (math.pi*2) / 3
 211                                 end
 212
 213                         -- Cause a fire
 214                         else
 215                                 minetest.set_node(pos2, {name = "mcl_fire:fire"})
 216                         end
 217                 end
 218         end
 219
 220 end
 221
 222 -- if other mods disable auto lightning during initialization, don't trigger the first lightning.
 223 minetest.after(5, function(dtime)
 224         if lightning.auto then
 225                 minetest.after(rng:next(lightning.interval_low,
 226                         lightning.interval_high), lightning.strike)
 227         end
 228 end)
 229
 230 minetest.register_chatcommand("lightning", {
 231         params = "[<X> <Y> <Z>]",
 232         description = S("Let lightning strike at the specified position or yourself"),
 233         privs = { maphack = true },
 234         func = function(name, param)
 235                 local pos = {}
 236                 pos.x, pos.y, pos.z = string.match(param, "^([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
 237                 pos.x = tonumber(pos.x)
 238                 pos.y = tonumber(pos.y)
 239                 pos.z = tonumber(pos.z)
 240                 if not (pos.x and pos.y and pos.z) then
 241                         pos = nil
 242                 end
 243                 if name == "" and pos == nil then
 244                         return false, "No position specified and unknown player"
 245                 end
 246                 if pos then
 247                         lightning.strike(pos)
 248                 else
 249                         local player = minetest.get_player_by_name(name)
 250                         if player then
 251                                 lightning.strike(player:get_pos())
 252                         else
 253                                 return false, S("No position specified and unknown player")
 254                         end
 255                 end
 256                 return true
 257         end,
 258 })
 259