refactor

init.lua

@@ -1,12 +1,24 @@
 -- Load setting
-local suffocation_damage = 10
-local setting = minetest.settings:get("real_suffocation_damage")
-if tonumber(setting) ~= nil then
-	suffocation_damage = tonumber(setting)
-end
+local suffocation_damage = tonumber(minetest.settings:get("real_suffocation_damage")) or 10
 
--- Skip the rest if suffocation damage is 0, no point in overwriting stuff
-if suffocation_damage > 0 then
+local function should_suffocate(def)
+--[[ Here comes the HUGE conditional deciding whether we use suffocation. We want to catch as many nodes as possible
+while avoiding bad nodes. We care mostly about physical properties, we don't care about visual appearance.
+Here's what it checks and why:
+- Walkable: Must be walkable, which means player can get stuck inside. If player can move freely, suffocation does not make sense
+- Drowning and damage: If node has set any of those explicitly, it probably knows why. We don't want to mess with it.
+- collision_box, node_box: Checks whether we deal with full-sized standard cubes, since only care about those.
+	Everything else is probably too small for suffocation to seem real.
+- disable_suffocation group: If set to 1, we bail out. This makes it possible for nodes to defend themselves against hacking. :-)
+]]
+
+	return (def.walkable == nil or def.walkable == true)
+		and (def.drowning == nil or def.drowning == 0)
+		and (def.damage_per_second == nil or def.damage_per_second <= 0)
+		and (def.collision_box == nil or def.collision_box.type == "regular")
+		and (def.node_box == nil or def.node_box.type == "regular")
+		and (def.groups.disable_suffocation ~= 1)
+end
 
 -- Checks all nodes and adds suffocation (drowning damage) for suitable nodes
 local function add_suffocation()
@@ -15,24 +27,9 @@ local function add_suffocation()
 	local no_suffocate_nodes = {}
 	-- Check ALL the nodes!
 	for itemstring, def in pairs(minetest.registered_nodes) do
-		--[[ Here comes the HUGE conditional deciding whether we use suffocation. We want to catch as many nodes as possible
-		while avoiding bad nodes. We care mostly about physical properties, we don't care about visual appearance.
-		Here's what it checks and why:
-		- Walkable: Must be walkable, which means player can get stuck inside. If player can move freely, suffocation does not make sense
-		- Drowning and damage: If node has set any of those explicitly, it probably knows why. We don't want to mess with it.
-		- collision_box, node_box: Checks whether we deal with full-sized standard cubes, since only care about those.
-			Everything else is probably too small for suffocation to seem real.
-		- disable_suffocation group: If set to 1, we bail out. This makes it possible for nodes to defend themselves against hacking. :-)
-		]]
-		if (def.walkable == nil or def.walkable == true) 
-		and (def.drowning == nil or def.drowning == 0)
-		and (def.damage_per_second == nil or def.damage_per_second <= 0)
-		and (def.collision_box == nil or def.collision_box.type == "regular")
-		and (def.node_box == nil or def.node_box.type == "regular")
-		and (def.groups.disable_suffocation ~= 1)
-		then
+		if should_suffocate(def) then
 			-- Add “real_suffocation” group so other mods know this node was touched by this mod
-			local marked_groups = def.groups
+			local marked_groups = table.copy(def.groups)
 			marked_groups.real_suffocation = 1
 			-- Let's hack the node!
 			minetest.override_item(itemstring, { drowning = suffocation_damage, groups = marked_groups })
@@ -46,7 +43,8 @@ local function add_suffocation()
 	minetest.log("verbose", "[real_suffocation] Suffocation has not been hacked into "..#no_suffocate_nodes.." nodes: "..dump(no_suffocate_nodes))
 end
 
--- This is a minor hack to make sure our loop runs after all nodes have been registered
-minetest.after(0, add_suffocation)
-
+-- Skip the rest if suffocation damage is 0, no point in overwriting stuff
+if suffocation_damage > 0 then
+	-- This is a minor hack to make sure our loop runs after all nodes have been registered
+	minetest.after(0, add_suffocation)
 end

mod.conf

@@ -1 +1,2 @@
 name = real_suffocation
+description = The player will lose breath inside solid blocks and suffers high damage when losing breath.