mods/ENVIRONMENT/lightning/init.lua

   1
   2 --[[
   3
   4 Copyright (C) 2016 - Auke Kok <sofar@foo-projects.org>
   5
   6 "lightning" is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU Lesser General Public License as
   8 published by the Free Software Foundation; either version 2.1
   9 of the license, or (at your option) any later version.
  10
  11 --]]
  12
  13 lightning = {}
  14
  15 lightning.interval_low = 17
  16 lightning.interval_high = 503
  17 lightning.range_h = 100
  18 lightning.range_v = 50
  19 lightning.size = 100
  20 -- disable this to stop lightning mod from striking
  21 lightning.auto = true
  22
  23 local rng = PcgRandom(32321123312123)
  24
  25 local ps = {}
  26 local ttl = -1
  27
  28 local revertsky = function(dtime)
  29         if ttl == 0 then
  30                 return
  31         end
  32         ttl = ttl - dtime
  33         if ttl > 0 then
  34                 return
  35         end
  36
  37         mcl_weather.skycolor.remove_layer("lightning")
  38
  39         ps = {}
  40 end
  41
  42 minetest.register_globalstep(revertsky)
  43
  44 -- select a random strike point, midpoint
  45 local function choose_pos(pos)
  46         if not pos then
  47                 local playerlist = minetest.get_connected_players()
  48                 local playercount = table.getn(playerlist)
  49
  50                 -- nobody on
  51                 if playercount == 0 then
  52                         return nil, nil
  53                 end
  54
  55                 local r = rng:next(1, playercount)
  56                 local randomplayer = playerlist[r]
  57                 pos = randomplayer:get_pos()
  58
  59                 -- avoid striking underground
  60                 if pos.y < -20 then
  61                         return nil, nil
  62                 end
  63
  64                 pos.x = math.floor(pos.x - (lightning.range_h / 2) + rng:next(1, lightning.range_h))
  65                 pos.y = pos.y + (lightning.range_v / 2)
  66                 pos.z = math.floor(pos.z - (lightning.range_h / 2) + rng:next(1, lightning.range_h))
  67         end
  68
  69         local b, pos2 = minetest.line_of_sight(pos, {x = pos.x, y = pos.y - lightning.range_v, z = pos.z}, 1)
  70
  71         -- nothing but air found
  72         if b then
  73                 return nil, nil
  74         end
  75
  76         local n = minetest.get_node({x = pos2.x, y = pos2.y - 1/2, z = pos2.z})
  77         if n.name == "air" or n.name == "ignore" then
  78                 return nil, nil
  79         end
  80
  81         return pos, pos2
  82 end
  83
  84 -- lightning strike API
  85 -- * pos: optional, if not given a random pos will be chosen
  86 -- * returns: bool - success if a strike happened
  87 lightning.strike = function(pos)
  88         if lightning.auto then
  89                 minetest.after(rng:next(lightning.interval_low, lightning.interval_high), lightning.strike)
  90         end
  91
  92         local pos2
  93         pos, pos2 = choose_pos(pos)
  94
  95         if not pos then
  96                 return false
  97         end
  98
  99         minetest.add_particlespawner({
 100                 amount = 1,
 101                 time = 0.2,
 102                 -- make it hit the top of a block exactly with the bottom
 103                 minpos = {x = pos2.x, y = pos2.y + (lightning.size / 2) + 1/2, z = pos2.z },
 104                 maxpos = {x = pos2.x, y = pos2.y + (lightning.size / 2) + 1/2, z = pos2.z },
 105                 minvel = {x = 0, y = 0, z = 0},
 106                 maxvel = {x = 0, y = 0, z = 0},
 107                 minacc = {x = 0, y = 0, z = 0},
 108                 maxacc = {x = 0, y = 0, z = 0},
 109                 minexptime = 0.2,
 110                 maxexptime = 0.2,
 111                 minsize = lightning.size * 10,
 112                 maxsize = lightning.size * 10,
 113                 collisiondetection = true,
 114                 vertical = true,
 115                 -- to make it appear hitting the node that will get set on fire, make sure
 116                 -- to make the texture lightning bolt hit exactly in the middle of the
 117                 -- texture (e.g. 127/128 on a 256x wide texture)
 118                 texture = "lightning_lightning_" .. rng:next(1,3) .. ".png",
 119         })
 120
 121         minetest.sound_play({ pos = pos, name = "lightning_thunder", gain = 10, max_hear_distance = 500 })
 122
 123         -- damage nearby objects, player or not
 124         for _, obj in ipairs(minetest.get_objects_inside_radius(pos, 5)) do
 125                 -- nil as param#1 is supposed to work, but core can't handle it.
 126                 obj:punch(obj, 1.0, {full_punch_interval = 1.0, damage_groups = {fleshy=8}}, nil)
 127         end
 128
 129         local playerlist = minetest.get_connected_players()
 130         for i = 1, #playerlist do
 131                 local player = playerlist[i]
 132                 local sky = {}
 133
 134                 sky.bgcolor, sky.type, sky.textures = player:get_sky()
 135
 136                 local name = player:get_player_name()
 137                 if ps[name] == nil then
 138                         ps[name] = {p = player, sky = sky}
 139                         mcl_weather.skycolor.add_layer("lightning", {{r=255,g=255,b=255}}, true)
 140                         mcl_weather.skycolor.active = true
 141                 end
 142         end
 143
 144         -- trigger revert of skybox
 145         ttl = 0.1
 146
 147         -- Events caused by the lightning strike: Fire, damage, mob transformations, rare skeleton spawn
 148
 149         pos2.y = pos2.y + 1/2
 150         local skeleton_lightning = false
 151         if rng:next(1,100) <= 3 then
 152                 skeleton_lightning = true
 153         end
 154         if minetest.get_item_group(minetest.get_node({x = pos2.x, y = pos2.y - 1, z = pos2.z}).name, "liquid") < 1 then
 155                 if minetest.get_node(pos2).name == "air" then
 156                         -- Low chance for a lightning to spawn skeleton horse + skeletons
 157                         if skeleton_lightning then
 158                                 minetest.add_entity(pos2, "mobs_mc:skeleton_horse")
 159
 160                                 local angle, posadd
 161                                 angle = math.random(0, math.pi*2)
 162                                 for i=1,3 do
 163                                         posadd = {x=math.cos(angle),y=0,z=math.sin(angle)}
 164                                         posadd = vector.normalize(posadd)
 165                                         local mob = minetest.add_entity(vector.add(pos2, posadd), "mobs_mc:skeleton")
 166                                         mob:setyaw(angle-math.pi/2)
 167                                         angle = angle + (math.pi*2) / 3
 168                                 end
 169
 170                         -- Cause a fire, deal damage, transform mobs
 171                         else
 172                                 minetest.set_node(pos2, {name = "mcl_fire:fire"})
 173
 174                                 local objs = minetest.get_objects_inside_radius(pos2, 3.5)
 175                                 for o=1, #objs do
 176                                         local obj = objs[o]
 177                                         local lua = obj:get_luaentity()
 178                                         if obj:is_player() then
 179                                                 -- Player damage
 180                                                 if minetest.get_modpath("mcl_death_messages") then
 181                                                         mcl_death_messages.player_damage(obj, string.format("%s was struck by lightning.", obj:get_player_name()))
 182                                                 end
 183                                                 obj:set_hp(obj:get_hp()-5)
 184                                         -- Mobs
 185                                         elseif lua and lua._cmi_is_mob then
 186                                                 -- pig → zombie pigman
 187                                                 if lua.name == "mobs_mc:pig" then
 188                                                         local rot = obj:get_yaw()
 189                                                         obj:remove()
 190                                                         obj = minetest.add_entity(pos2, "mobs_mc:pigman")
 191                                                         obj:set_yaw(rot)
 192                                                 -- villager → witch
 193                                                 elseif lua.name == "mobs_mc:villager" then
 194                                                 -- Witches are incomplete, this code is unused
 195                                                 -- TODO: Enable this code when witches are working.
 196                                                 --[[
 197                                                         local rot = obj:get_yaw()
 198                                                         obj:remove()
 199                                                         obj = minetest.add_entity(pos2, "mobs_mc:witch")
 200                                                         obj:set_yaw(rot)
 201                                                 ]]
 202                                                 -- TODO: creeper → charged creeper
 203                                                 elseif lua.name == "mobs_mc:creeper" then
 204
 205                                                 -- Other mobs: Just Damage
 206                                                 else
 207                                                         obj:set_hp(obj:get_hp()-5)
 208                                                 end
 209                                         end
 210                                 end
 211                         end
 212                 end
 213                 -- TODO: Charged creeper
 214         end
 215
 216 end
 217
 218 -- if other mods disable auto lightning during initialization, don't trigger the first lightning.
 219 minetest.after(5, function(dtime)
 220         if lightning.auto then
 221                 minetest.after(rng:next(lightning.interval_low,
 222                         lightning.interval_high), lightning.strike)
 223         end
 224 end)