Prevent divide by zero (#2106)

This forces all explosions to damage entities within the 1 node
range. If that needs to be disabled, the damage_radius needs to
be set to 0.

README.txt

@@ -31,7 +31,10 @@ in mining.
 How to use the mod:
 Craft gunpowder by placing coal and gravel in the crafting area.
 The gunpowder can be used to craft TNT or as fuse for TNT.
-To craft TNT surround gunpowder with 4 wood in a + shape.
+To craft TNT place items like this:
+-- wood - gunpowder -- wood -
+gunpowder gunpowder gunpowder
+-- wood - gunpowder -- wood -
 
 There are different ways to blow up TNT:
   1. Hit it with a torch.

init.lua

@@ -1,7 +1,7 @@
 tnt = {}
 
 -- Default to enabled when in singleplayer
-local enable_tnt = minetest.setting_getbool("enable_tnt")
+local enable_tnt = minetest.settings:get_bool("enable_tnt")
 if enable_tnt == nil then
 	enable_tnt = minetest.is_singleplayer()
 end
@@ -12,7 +12,7 @@ local loss_prob = {}
 loss_prob["default:cobble"] = 3
 loss_prob["default:dirt"] = 4
 
-local tnt_radius = tonumber(minetest.setting_get("tnt_radius") or 3)
+local tnt_radius = tonumber(minetest.settings:get("tnt_radius") or 3)
 
 -- Fill a list with data for content IDs, after all nodes are registered
 local cid_data = {}
@@ -83,8 +83,11 @@ local function add_drop(drops, item)
 	end
 end
 
-local function destroy(drops, npos, cid, c_air, c_fire, on_blast_queue, ignore_protection, ignore_on_blast)
-	if not ignore_protection and minetest.is_protected(npos, "") then
+local basic_flame_on_construct -- cached value
+local function destroy(drops, npos, cid, c_air, c_fire,
+		on_blast_queue, on_construct_queue,
+		ignore_protection, ignore_on_blast, owner)
+	if not ignore_protection and minetest.is_protected(npos, owner) then
 		return cid
 	end
 
@@ -93,9 +96,16 @@ local function destroy(drops, npos, cid, c_air, c_fire, on_blast_queue, ignore_p
 	if not def then
 		return c_air
 	elseif not ignore_on_blast and def.on_blast then
-		on_blast_queue[#on_blast_queue + 1] = {pos = vector.new(npos), on_blast = def.on_blast}
+		on_blast_queue[#on_blast_queue + 1] = {
+			pos = vector.new(npos),
+			on_blast = def.on_blast
+		}
 		return cid
 	elseif def.flammable then
+		on_construct_queue[#on_construct_queue + 1] = {
+			fn = basic_flame_on_construct,
+			pos = vector.new(npos)
+		}
 		return c_fire
 	else
 		local node_drops = minetest.get_node_drops(def.name, "")
@@ -198,6 +208,7 @@ local function add_effects(pos, radius, drops)
 		collisiondetection = false,
 		vertical = false,
 		texture = "tnt_boom.png",
+		glow = 15,
 	})
 	minetest.add_particlespawner({
 		amount = 64,
@@ -250,17 +261,19 @@ end
 
 function tnt.burn(pos, nodename)
 	local name = nodename or minetest.get_node(pos).name
-	local group = minetest.get_item_group(name, "tnt")
-	if group > 0 then
+	local def = minetest.registered_nodes[name]
+	if not def then
+		return
+	elseif def.on_ignite then
+		def.on_ignite(pos)
+	elseif minetest.get_item_group(name, "tnt") > 0 then
+		minetest.swap_node(pos, {name = name .. "_burning"})
 		minetest.sound_play("tnt_ignite", {pos = pos})
-		minetest.set_node(pos, {name = name .. "_burning"})
 		minetest.get_node_timer(pos):start(1)
-	elseif name == "tnt:gunpowder" then
-		minetest.set_node(pos, {name = "tnt:gunpowder_burning"})
 	end
 end
 
-local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
+local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast, owner, explode_center)
 	pos = vector.round(pos)
 	-- scan for adjacent TNT nodes first, and enlarge the explosion
 	local vm1 = VoxelManip()
@@ -274,6 +287,10 @@ local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
 	local c_tnt_burning = minetest.get_content_id("tnt:tnt_burning")
 	local c_tnt_boom = minetest.get_content_id("tnt:boom")
 	local c_air = minetest.get_content_id("air")
+	-- make sure we still have explosion even when centre node isnt tnt related
+	if explode_center then
+		count = 1
+	end
 
 	for z = pos.z - 2, pos.z + 2 do
 	for y = pos.y - 2, pos.y + 2 do
@@ -306,6 +323,8 @@ local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
 
 	local drops = {}
 	local on_blast_queue = {}
+	local on_construct_queue = {}
+	basic_flame_on_construct = minetest.registered_nodes["fire:basic_flame"].on_construct
 
 	local c_fire = minetest.get_content_id("fire:basic_flame")
 	for z = -radius, radius do
@@ -318,8 +337,8 @@ local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
 			local p = {x = pos.x + x, y = pos.y + y, z = pos.z + z}
 			if cid ~= c_air then
 				data[vi] = destroy(drops, p, cid, c_air, c_fire,
-					on_blast_queue, ignore_protection,
-					ignore_on_blast)
+					on_blast_queue, on_construct_queue,
+					ignore_protection, ignore_on_blast, owner)
 			end
 		end
 		vi = vi + 1
@@ -357,21 +376,37 @@ local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
 		end
 	end
 
+	for _, queued_data in pairs(on_construct_queue) do
+		queued_data.fn(queued_data.pos)
+	end
+
+	minetest.log("action", "TNT owned by " .. owner .. " detonated at " ..
+		minetest.pos_to_string(pos) .. " with radius " .. radius)
+
 	return drops, radius
 end
 
 function tnt.boom(pos, def)
-	minetest.sound_play("tnt_explode", {pos = pos, gain = 1.5, max_hear_distance = 2*64})
+	def = def or {}
+	def.radius = def.radius or 1
+	def.damage_radius = def.damage_radius or def.radius * 2
+	local meta = minetest.get_meta(pos)
+	local owner = meta:get_string("owner")
+	if not def.explode_center then
 		minetest.set_node(pos, {name = "tnt:boom"})
+	end
+	minetest.sound_play("tnt_explode", {pos = pos, gain = 1.5, max_hear_distance = 2*64})
 	local drops, radius = tnt_explode(pos, def.radius, def.ignore_protection,
-			def.ignore_on_blast)
+			def.ignore_on_blast, owner, def.explode_center)
 	-- append entity drops
-	local damage_radius = (radius / def.radius) * def.damage_radius
+	local damage_radius = (radius / math.max(1, def.radius)) * def.damage_radius
 	entity_physics(pos, damage_radius, drops)
 	if not def.disable_drops then
 		eject_drops(drops, pos, radius)
 	end
 	add_effects(pos, radius, drops)
+	minetest.log("action", "A TNT explosion occurred at " .. minetest.pos_to_string(pos) ..
+		" with radius " .. radius)
 end
 
 minetest.register_node("tnt:boom", {
@@ -380,12 +415,6 @@ minetest.register_node("tnt:boom", {
 	walkable = false,
 	drop = "",
 	groups = {dig_immediate = 3},
-	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(0.4)
-	end,
-	on_timer = function(pos, elapsed)
-		minetest.remove_node(pos)
-	end,
 	-- unaffected by explosions
 	on_blast = function() end,
 })
@@ -397,7 +426,12 @@ minetest.register_node("tnt:gunpowder", {
 	is_ground_content = false,
 	sunlight_propagates = true,
 	walkable = false,
-	tiles = {"tnt_gunpowder_straight.png", "tnt_gunpowder_curved.png", "tnt_gunpowder_t_junction.png", "tnt_gunpowder_crossing.png"},
+	tiles = {
+		"tnt_gunpowder_straight.png",
+		"tnt_gunpowder_curved.png",
+		"tnt_gunpowder_t_junction.png",
+		"tnt_gunpowder_crossing.png"
+	},
 	inventory_image = "tnt_gunpowder_inventory.png",
 	wield_image = "tnt_gunpowder_inventory.png",
 	selection_box = {
@@ -411,6 +445,9 @@ minetest.register_node("tnt:gunpowder", {
 	on_punch = function(pos, node, puncher)
 		if puncher:get_wielded_item():get_name() == "default:torch" then
 			minetest.set_node(pos, {name = "tnt:gunpowder_burning"})
+			minetest.log("action", puncher:get_player_name() ..
+				" ignites tnt:gunpowder at " ..
+				minetest.pos_to_string(pos))
 		end
 	end,
 	on_blast = function(pos, intensity)
@@ -471,13 +508,17 @@ minetest.register_node("tnt:gunpowder_burning", {
 		fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2},
 	},
 	drop = "",
-	groups = {dig_immediate = 2, attached_node = 1, connect_to_raillike = minetest.raillike_group("gunpowder")},
+	groups = {
+		dig_immediate = 2,
+		attached_node = 1,
+		connect_to_raillike = minetest.raillike_group("gunpowder")
+	},
 	sounds = default.node_sound_leaves_defaults(),
 	on_timer = function(pos, elapsed)
 		for dx = -1, 1 do
 		for dz = -1, 1 do
+			if math.abs(dx) + math.abs(dz) == 1 then
 				for dy = -1, 1 do
-			if not (dx == 0 and dz == 0) then
 					tnt.burn({
 						x = pos.x + dx,
 						y = pos.y + dy,
@@ -498,7 +539,7 @@ minetest.register_node("tnt:gunpowder_burning", {
 })
 
 minetest.register_craft({
-	output = "tnt:gunpowder",
+	output = "tnt:gunpowder 5",
 	type = "shapeless",
 	recipe = {"default:coal_lump", "default:gravel"}
 })
@@ -507,9 +548,9 @@ if enable_tnt then
 	minetest.register_craft({
 		output = "tnt:tnt",
 		recipe = {
-			{"",           "group:wood",    ""},
 			{"group:wood",    "tnt:gunpowder", "group:wood"},
-			{"",           "group:wood",    ""}
+			{"tnt:gunpowder", "tnt:gunpowder", "tnt:gunpowder"},
+			{"group:wood",    "tnt:gunpowder", "group:wood"}
 		}
 	})
 
@@ -547,9 +588,19 @@ function tnt.register_tnt(def)
 			is_ground_content = false,
 			groups = {dig_immediate = 2, mesecon = 2, tnt = 1, flammable = 5},
 			sounds = default.node_sound_wood_defaults(),
+			after_place_node = function(pos, placer)
+				if placer:is_player() then
+					local meta = minetest.get_meta(pos)
+					meta:set_string("owner", placer:get_player_name())
+				end
+			end,
 			on_punch = function(pos, node, puncher)
 				if puncher:get_wielded_item():get_name() == "default:torch" then
-					minetest.set_node(pos, {name = name .. "_burning"})
+					minetest.swap_node(pos, {name = name .. "_burning"})
+					minetest.registered_nodes[name .. "_burning"].on_construct(pos)
+					minetest.log("action", puncher:get_player_name() ..
+						" ignites " .. node.name .. " at " ..
+						minetest.pos_to_string(pos))
 				end
 			end,
 			on_blast = function(pos, intensity)
@@ -565,10 +616,12 @@ function tnt.register_tnt(def)
 				}
 			},
 			on_burn = function(pos)
-				minetest.set_node(pos, {name = name .. "_burning"})
+				minetest.swap_node(pos, {name = name .. "_burning"})
+				minetest.registered_nodes[name .. "_burning"].on_construct(pos)
 			end,
 			on_ignite = function(pos, igniter)
-				minetest.set_node(pos, {name = name .. "_burning"})
+				minetest.swap_node(pos, {name = name .. "_burning"})
+				minetest.registered_nodes[name .. "_burning"].on_construct(pos)
 			end,
 		})
 	end