Prevent mobs from spawning on bedrock

This patch keeps the Nether roof mob-free.

mods/CORE/mcl_init/init.lua

@@ -131,9 +131,9 @@ mcl_vars.mg_overworld_max = mcl_vars.mapgen_edge_max
 
 -- The Nether (around Y = -29000)
 mcl_vars.mg_nether_min = -29067 -- Carefully chosen to be at a mapchunk border
-mcl_vars.mg_nether_max = mcl_vars.mg_nether_min + 128
+mcl_vars.mg_nether_max = mcl_vars.mg_nether_min + 256
 mcl_vars.mg_bedrock_nether_bottom_min = mcl_vars.mg_nether_min
-mcl_vars.mg_bedrock_nether_top_max = mcl_vars.mg_nether_max
+mcl_vars.mg_bedrock_nether_top_max = mcl_vars.mg_nether_max - 128
 if not superflat then
 	mcl_vars.mg_bedrock_nether_bottom_max = mcl_vars.mg_bedrock_nether_bottom_min + 4
 	mcl_vars.mg_bedrock_nether_top_min = mcl_vars.mg_bedrock_nether_top_max - 4

mods/ENTITIES/mobs_mc/5_spawn_abm_check.lua

@@ -1,13 +1,16 @@
 local function is_forbidden_node(pos, node)
 	node = node or minetest.get_node(pos)
-	return minetest.get_item_group(node.name, "stair") > 0 or minetest.get_item_group(node.name, "slab") > 0 or minetest.get_item_group(node.name, "carpet") > 0
+	return "mcl_core:bedrock" == node.name or
+	   minetest.get_item_group(node.name, "stair") > 0 or
+	   minetest.get_item_group(node.name, "slab") > 0 or
+	   minetest.get_item_group(node.name, "carpet") > 0
 end
 
 function mobs:spawn_abm_check(pos, node, name)
 	-- Don't spawn monsters on mycelium
 	if (node.name == "mcl_core:mycelium" or node.name == "mcl_core:mycelium_snow") and minetest.registered_entities[name].type == "monster" then
 		return true
-    --Don't Spawn mobs on stairs, slabs, or carpets
+	-- Don't spawn mobs on bedrock, stairs, slabs, or carpets
 	elseif is_forbidden_node(pos, node) or is_forbidden_node(vector.add(pos, vector.new(0, 1, 0))) then
 		return true
 	-- Spawn on opaque or liquid nodes

mods/MAPGEN/mcl_biomes/init.lua

@@ -2008,7 +2008,7 @@ local function register_dimension_ores()
 		clust_scarcity  = 26 * 26 * 26,
 		clust_size      = 5,
 		y_min           = mcl_vars.mg_lava_nether_max + 10,
-		y_max           = mcl_vars.mg_nether_max,
+		y_max           = mcl_vars.mg_bedrock_nether_top_max - 1,
 		noise_threshold = 0.0,
 		noise_params    = {
 			offset = 0.5,
@@ -2052,7 +2052,7 @@ local function register_dimension_ores()
 			clust_num_ores = 4, -- MC cluster amount: 4-10
 			clust_size     = 3,
 			y_min = mcl_vars.mg_nether_min,
-			y_max = mcl_vars.mg_nether_max,
+			y_max = mcl_vars.mg_bedrock_nether_top_max - 1,
 		})
 		minetest.register_ore({
 			ore_type       = "scatter",
@@ -2062,7 +2062,7 @@ local function register_dimension_ores()
 			clust_num_ores = 8, -- MC cluster amount: 4-10
 			clust_size     = 4,
 			y_min = mcl_vars.mg_nether_min,
-			y_max = mcl_vars.mg_nether_max,
+			y_max = mcl_vars.mg_bedrock_nether_top_max - 1,
 		})
 	end
 
@@ -2107,7 +2107,7 @@ local function register_dimension_ores()
 		clust_num_ores = 1,
 		clust_size     = 1,
 		y_min           = mcl_vars.mg_lava_nether_max + 49,
-		y_max           = mcl_vars.mg_nether_max,
+		y_max           = mcl_vars.mg_bedrock_nether_top_max - 1,
 	})
 
 	--[[ THE END ]]

mods/MAPGEN/mcl_mapgen_core/init.lua

@@ -1,4 +1,9 @@
-mcl_mapgen_core = {}
+mcl_mapgen_core = {
+	replace_nether_roof_void_with_air = minetest.settings:get_bool(
+		"mcl_mapgen_core_replace_nether_roof_void_with_air",
+		false
+	)
+}
 mcl_mapgen_core.registered_generators = {}
 
 local lvm, nodes, param2 = 0, 0, 0
@@ -1784,7 +1789,7 @@ end
 -- Generate Nether decorations manually: Eternal fire, mushrooms, nether wart
 -- Minetest's API does not support decorations in caves yet. :-(
 local generate_nether_decorations = function(minp, maxp, seed)
-	if minp.y > mcl_vars.mg_nether_max or maxp.y < mcl_vars.mg_nether_min then
+	if minp.y > mcl_vars.mg_bedrock_nether_top_max or maxp.y < mcl_vars.mg_nether_min then
 		return
 	end
 
@@ -2022,9 +2027,32 @@ local function basic(vm, data, data2, emin, emax, area, minp, maxp, blockseed)
 	-- [[ THE NETHER:					mcl_vars.mg_nether_min			       mcl_vars.mg_nether_max							]]
 
 	-- The Air on the Nether roof, https://git.minetest.land/MineClone2/MineClone2/issues/1186
-	lvm_used = set_layers(data, area, c_air		 , nil, mcl_vars.mg_nether_max			   +1, mcl_vars.mg_nether_max + 128                 , minp, maxp, lvm_used, pr)
+	-- This was modified later, see https://git.minetest.land/Mineclonia/Mineclonia/issues/270
+	lvm_used = set_layers(
+		data,
+		area,
+		c_air,
+		nil,
+		mcl_vars.mg_bedrock_nether_top_max + 1,
+		mcl_vars.mg_nether_max,
+		minp,
+		maxp,
+		lvm_used,
+		pr
+	)
 	-- The Void above the Nether below the End:
-	lvm_used = set_layers(data, area, c_void         , nil, mcl_vars.mg_nether_max + 128               +1, mcl_vars.mg_end_min                        -1, minp, maxp, lvm_used, pr)
+	lvm_used = set_layers(
+		data,
+		area,
+		c_void,
+		nil,
+		mcl_vars.mg_nether_max + 1,
+		mcl_vars.mg_end_min - 1,
+		minp,
+		maxp,
+		lvm_used,
+		pr
+	)
 
 	-- [[ THE END:						mcl_vars.mg_end_min			       mcl_vars.mg_end_max							]]
 
@@ -2136,15 +2164,25 @@ local function basic(vm, data, data2, emin, emax, area, minp, maxp, blockseed)
 			if mg_name == "v6" then
 				nodes = minetest.find_nodes_in_area(emin, emax, {"mcl_core:water_source", "mcl_core:stone", "mcl_core:sand", "mcl_core:dirt"})
 			else
-				nodes = minetest.find_nodes_in_area(emin, emax, {"mcl_core:water_source"})
+				nodes = minetest.find_nodes_in_area(emin, emax, {"mcl_core:water_source", "mcl_core:stone"})
 			end
 			for n=1, #nodes do
 				local p_pos = area:index(nodes[n].x, nodes[n].y, nodes[n].z)
 				if data[p_pos] == c_water then
-					data[p_pos] = c_nether_lava
+					if nodes[n].y > mcl_vars.mg_bedrock_nether_top_max then
+						data[p_pos] = c_air  -- no lava on the roof pls
+					else
+						data[p_pos] = c_nether_lava
+					end
 					lvm_used = true
 				elseif data[p_pos] == c_stone then
-					data[p_pos] = c_netherrack
+					-- this deals with random stone layers Minetest creates
+					-- see https://github.com/minetest/minetest/issues/9357
+					if nodes[n].y > mcl_vars.mg_bedrock_nether_top_max then
+						data[p_pos] = c_air  -- remove stone clouds
+					else
+						data[p_pos] = c_netherrack  -- remove stone
+					end
 					lvm_used = true
 				elseif data[p_pos] == c_sand or data[p_pos] == c_dirt then
 					data[p_pos] = c_soul_sand
@@ -2267,3 +2305,24 @@ function mcl_mapgen_core.get_node(p, force, us_timeout)
 	return node
 	-- it still can return "ignore", LOL, even if force = true, but only after time out
 end
+
+
+if mcl_mapgen_core.replace_nether_roof_void_with_air then
+	minetest.register_lbm({
+		label = "Replace Nether roof void from MineClone2 <0.71 with air",
+		name = "mcl_mapgen_core:replace_nether_roof_void_with_air",
+		nodenames = { "mcl_core:void" },
+		run_at_every_load = false,
+		action = function(pos, node)
+			if (
+				pos.y >= mcl_vars.mg_bedrock_nether_top_max and
+				pos.y <= mcl_vars.mg_nether_max
+			) then
+				minetest.swap_node(
+					pos,
+					{ name="air" }
+				)
+			end
+		end,
+	})
+end

settingtypes.txt

@@ -152,3 +152,8 @@ basic_pseudobiome_villages (Enables very basic, and experimental "pseudobiome-ba
 
 # If enabled, will run an LBM to fix the top 1/2 of double plants in mcimported worlds; defaults to true.
 fix_doubleplants (Mcimport double plant fixes) bool true
+
+# If enabled, will run an LBM to replace void nodes on the Nether roof generated by MineClone2 <0.71 with air.
+# Activate this setting if you generated some Nether in MineClone2 <0.71 and want to build on the Nether roof.
+# WARNING: This setting has quite poor performance and may lag Minetest while affected areas are being fixed.
+mcl_mapgen_core_replace_nether_roof_void_with_air (Replace Nether roof void from MineClone2 <0.71 with air) bool false