From c81a18ac1a7c5ee791da1bfeb3289ac50170815e Mon Sep 17 00:00:00 2001
From: Wuzzy <Wuzzy2@mail.ru>
Date: Wed, 22 Apr 2020 01:38:41 +0200
Subject: [PATCH] Refactor mcl_void_damage

---
 mods/ENVIRONMENT/mcl_void_damage/init.lua | 85 ++++++++++++++++-------
 1 file changed, 61 insertions(+), 24 deletions(-)

diff --git a/mods/ENVIRONMENT/mcl_void_damage/init.lua b/mods/ENVIRONMENT/mcl_void_damage/init.lua
index 5490f5000..f48244147 100644
--- a/mods/ENVIRONMENT/mcl_void_damage/init.lua
+++ b/mods/ENVIRONMENT/mcl_void_damage/init.lua
@@ -1,42 +1,79 @@
 local S = minetest.get_translator("mcl_void_damage")
+local enable_damage = minetest.settings:get_bool("enable_damage")
 
 local voidtimer = 0
+local VOID_DAMAGE_FREQ = 0.5
+local VOID_DAMAGE = 4
+
+-- Remove entities that fall too deep into the void
+minetest.register_on_mods_loaded(function()
+	-- We do this by overwriting on_step of all entities
+	for entitystring, def in pairs(minetest.registered_entities) do
+		local on_step_old = def.on_step
+		if not on_step_old then
+			on_step_old = function() end
+		end
+		local on_step = function(self, dtime)
+			on_step_old(self, dtime)
+			local obj = self.object
+			local pos = obj:get_pos()
+			-- Old on_step function might have deleted object,
+			-- so we delete it
+			if not pos then
+				return
+			end
+
+			if not self._void_timer then
+				self._void_timer = 0
+			end
+			self._void_timer = self._void_timer + dtime
+			if self._void_timer <= VOID_DAMAGE_FREQ then
+				return
+			end
+			self._void_timer = 0
 
-minetest.register_globalstep(function(dtime)
-	voidtimer = voidtimer + dtime
-	if voidtimer > 0.5 then
-		voidtimer = 0
-		local objs = minetest.object_refs
-		local enable_damage = minetest.settings:get_bool("enable_damage")
-		for id, obj in pairs(objs) do
 			local pos = obj:get_pos()
 			local void, void_deadly = mcl_worlds.is_in_void(pos)
 			if void_deadly then
-				local is_player = obj:is_player()
 				local ent = obj:get_luaentity()
-				local immortal_val = obj:get_armor_groups().immortal
+				obj:remove()
+				return
+			end
+		end
+		def.on_step = on_step
+		minetest.register_entity(":"..entitystring, def)
+	end
+end)
+
+-- Hurt players or teleport them back to spawn if they are too deep in the void
+minetest.register_globalstep(function(dtime)
+	voidtimer = voidtimer + dtime
+	if voidtimer > VOID_DAMAGE_FREQ then
+		voidtimer = 0
+		local enable_damage = minetest.settings:get_bool("enable_damage")
+		local players = minetest.get_connected_players()
+		for p=1, #players do
+			local player = players[p]
+			local pos = player:get_pos()
+			local void, void_deadly = mcl_worlds.is_in_void(pos)
+			if void_deadly then
+				local immortal_val = player:get_armor_groups().immortal
 				local is_immortal = false
 				if immortal_val and immortal_val > 0 then
 					is_immortal = true
 				end
 				if is_immortal or not enable_damage then
-					if is_player then
-						-- If damage is disabled, we can't kill players.
-						-- So we just teleport the player back to spawn.
-						local spawn = mcl_spawn.get_spawn_pos(obj)
-						obj:set_pos(spawn)
-						mcl_worlds.dimension_change(obj, mcl_worlds.pos_to_dimension(spawn))
-						minetest.chat_send_player(obj:get_player_name(), S("The void is off-limits to you!"))
-					else
-						obj:remove()
-					end
+					-- If damage is disabled, we can't kill players.
+					-- So we just teleport the player back to spawn.
+					local spawn = mcl_spawn.get_spawn_pos(player)
+					player:set_pos(spawn)
+					mcl_worlds.dimension_change(player, mcl_worlds.pos_to_dimension(spawn))
+					minetest.chat_send_player(player:get_player_name(), S("The void is off-limits to you!"))
 				elseif enable_damage and not is_immortal then
 					-- Damage enabled, not immortal: Deal void damage (4 HP / 0.5 seconds)
-					if obj:get_hp() > 0 then
-						if is_player then
-							mcl_death_messages.player_damage(obj, S("@1 fell into the endless void.", obj:get_player_name()))
-						end
-						obj:set_hp(obj:get_hp() - 4)
+					if player:get_hp() > 0 then
+						mcl_death_messages.player_damage(player, S("@1 fell into the endless void.", player:get_player_name()))
+						player:set_hp(player:get_hp() - VOID_DAMAGE)
 					end
 				end
 			end