From 17c5b66524d3bb4f09c3cc83007901b4cac1a7d5 Mon Sep 17 00:00:00 2001 From: Zefram Date: Thu, 24 Jul 2014 17:38:53 +0100 Subject: [PATCH] Inverse square law for radiation damage --- technic/machines/HV/nuclear_reactor.lua | 54 +++++++++++++++++++++---- 1 file changed, 47 insertions(+), 7 deletions(-) diff --git a/technic/machines/HV/nuclear_reactor.lua b/technic/machines/HV/nuclear_reactor.lua index b240a9d..7244a0f 100644 --- a/technic/machines/HV/nuclear_reactor.lua +++ b/technic/machines/HV/nuclear_reactor.lua @@ -12,6 +12,15 @@ local fuel_type = "technic:uranium_fuel" -- The reactor burns this stuff local S = technic.getter +if not vector.distance_square then + vector.distance_square = function (u, v) + local dx = v.x - u.x + local dy = v.y - u.y + local dz = v.z - u.z + return dx*dx + dy*dy + dz*dz + end +end + -- FIXME: recipe must make more sense like a rod recepticle, steam chamber, HV generator? minetest.register_craft({ output = 'technic:hv_nuclear_reactor_core', @@ -211,7 +220,7 @@ minetest.register_node("technic:hv_nuclear_reactor_core_active", { tiles = {"technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png", "technic_hv_nuclear_reactor_core.png"}, - groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2, technic_machine=1, radioactive=2, not_in_creative_inventory=1}, + groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2, technic_machine=1, radioactive=3, not_in_creative_inventory=1}, legacy_facedir_simple = true, sounds = default.node_sound_wood_defaults(), drop="technic:hv_nuclear_reactor_core", @@ -257,15 +266,46 @@ technic.register_machine("HV", "technic:hv_nuclear_reactor_core_active", technic -- radioactive materials that can result from destroying a reactor +local assumed_abdomen_offset = vector.new(0, 1, 0) +local assumed_abdomen_offset_length = vector.length(assumed_abdomen_offset) + minetest.register_abm({ nodenames = {"group:radioactive"}, interval = 1, chance = 1, action = function (pos, node) - for r = 1, minetest.registered_nodes[node.name].groups.radioactive do - for _, o in ipairs(minetest.get_objects_inside_radius(pos, r*2)) do - if o:is_player() then - o:set_hp(math.max(o:get_hp() - 1, 0)) + -- Damage depends on distance between the radiation source + -- and the player, with an inverse square relationship. + -- The "radioactive" group value is the distance in + -- metres from a node at which a player will be damaged by + -- 1 HP/s. Or, equivalently, it is the square root of the + -- damage rate in HP/s that a player 1 m away will take. + local strength = minetest.registered_nodes[node.name].groups.radioactive + -- Damage is processed at rates down to 0.25 HP/s, + -- which is attained at twice the 1 HP/s distance. + for _, o in ipairs(minetest.get_objects_inside_radius(pos, strength*2 + assumed_abdomen_offset_length)) do + if o:is_player() then + -- If the player is very close, swimming + -- in radioactive liquid, then the nominal + -- distance could go to zero, but in + -- that case we model the player's body + -- displacing the liquid and increasing + -- the effective distance to non-zero. + -- The minimum effective distance is set + -- to the maximum distance one can get + -- from the node centre within the node, + -- so that swimming in radioactive liquid + -- gives a uniform effective distance. + local dist_sq = math.max(0.75, vector.distance_square(pos, vector.add(o:getpos(), assumed_abdomen_offset))) + local dmg_rate = strength*strength/dist_sq + if dmg_rate >= 0.25 then + local dmg_int = math.floor(dmg_rate) + if math.random() < dmg_rate-dmg_int then + dmg_int = dmg_int + 1 + end + if dmg_int > 0 then + o:set_hp(math.max(o:get_hp() - dmg_int, 0)) + end end end end @@ -305,7 +345,7 @@ for _, state in ipairs({ "flowing", "source" }) do liquid = 2, hot = 3, igniter = 1, - radioactive = (state == "source" and 3 or 2), + radioactive = (state == "source" and 4 or 3), not_in_creative_inventory = (state == "flowing" and 1 or nil), }, }) @@ -325,7 +365,7 @@ minetest.register_node("technic:chernobylite_block", { description = S("Chernobylite Block"), tiles = { "technic_chernobylite_block.png" }, is_ground_content = true, - groups = { cracky=1, radioactive=1, level=2 }, + groups = { cracky=1, radioactive=2, level=2 }, sounds = default.node_sound_stone_defaults(), light_source = 2,