Improve Nether Portals (#1315) (as a squash)

Remove Nether portal caches, https://git.minetest.land/MineClone2/MineClone2/issues/1210

Store all exits from Nether portals in quick-access table

Implement proper Nether portal search, using the table, https://git.minetest.land/MineClone2/MineClone2/issues/1055

Store Nether portal exits table in mod storage

Remove exits from table on Nether portal destruction

Align destination area to [map chunks 5x5x5](https://git.minetest.land/MineClone2/MineClone2/wiki/World-structure%3A-positions%2C-boundaries%2C-blocks%2C-chunks%2C-dimensions%2C-barriers-and-the-void) to avoid lots of ```emerge_area()``` calls

Support Nether roof, https://git.minetest.land/MineClone2/MineClone2/issues/1267

Implement better suitable place search, https://git.minetest.land/MineClone2/MineClone2/issues/1126

Implement object queue not to trigger the same search again

Avoid lava lakes, https://git.minetest.land/MineClone2/MineClone2/issues/1126

Add ```/spawnstruct nether_portal``` chat command
Co-Authored-By: kay27 <kay27@noreply.git.minetest.land>
Co-Committed-By: kay27 <kay27@noreply.git.minetest.land>

mods/CORE/mcl_init/init.lua

@@ -33,25 +33,26 @@ mcl_vars.MAP_BLOCKSIZE = math.max(1, core.MAP_BLOCKSIZE or 16)
 mcl_vars.mapgen_limit = math.max(1, tonumber(minetest.get_mapgen_setting("mapgen_limit")) or 31000)
 mcl_vars.MAX_MAP_GENERATION_LIMIT = math.max(1, core.MAX_MAP_GENERATION_LIMIT or 31000)
 local central_chunk_offset = -math.floor(mcl_vars.chunksize / 2)
-local chunk_size_in_nodes = mcl_vars.chunksize * mcl_vars.MAP_BLOCKSIZE
+mcl_vars.central_chunk_offset_in_nodes = central_chunk_offset * mcl_vars.MAP_BLOCKSIZE
+mcl_vars.chunk_size_in_nodes = mcl_vars.chunksize * mcl_vars.MAP_BLOCKSIZE
 local central_chunk_min_pos = central_chunk_offset * mcl_vars.MAP_BLOCKSIZE
-local central_chunk_max_pos = central_chunk_min_pos + chunk_size_in_nodes - 1
+local central_chunk_max_pos = central_chunk_min_pos + mcl_vars.chunk_size_in_nodes - 1
 local ccfmin = central_chunk_min_pos - mcl_vars.MAP_BLOCKSIZE -- Fullminp/fullmaxp of central chunk, in nodes
 local ccfmax = central_chunk_max_pos + mcl_vars.MAP_BLOCKSIZE
 local mapgen_limit_b = math.floor(math.min(mcl_vars.mapgen_limit, mcl_vars.MAX_MAP_GENERATION_LIMIT) / mcl_vars.MAP_BLOCKSIZE)
 local mapgen_limit_min = -mapgen_limit_b * mcl_vars.MAP_BLOCKSIZE
 local mapgen_limit_max = (mapgen_limit_b + 1) * mcl_vars.MAP_BLOCKSIZE - 1
-local numcmin = math.max(math.floor((ccfmin - mapgen_limit_min) / chunk_size_in_nodes), 0) -- Number of complete chunks from central chunk
-local numcmax = math.max(math.floor((mapgen_limit_max - ccfmax) / chunk_size_in_nodes), 0) -- fullminp/fullmaxp to effective mapgen limits.
-mcl_vars.mapgen_edge_min = central_chunk_min_pos - numcmin * chunk_size_in_nodes
-mcl_vars.mapgen_edge_max = central_chunk_max_pos + numcmax * chunk_size_in_nodes
+local numcmin = math.max(math.floor((ccfmin - mapgen_limit_min) / mcl_vars.chunk_size_in_nodes), 0) -- Number of complete chunks from central chunk
+local numcmax = math.max(math.floor((mapgen_limit_max - ccfmax) / mcl_vars.chunk_size_in_nodes), 0) -- fullminp/fullmaxp to effective mapgen limits.
+mcl_vars.mapgen_edge_min = central_chunk_min_pos - numcmin * mcl_vars.chunk_size_in_nodes
+mcl_vars.mapgen_edge_max = central_chunk_max_pos + numcmax * mcl_vars.chunk_size_in_nodes
 
 local function coordinate_to_block(x)
 	return math.floor(x / mcl_vars.MAP_BLOCKSIZE)
 end
 
 local function coordinate_to_chunk(x)
-	return math.floor((coordinate_to_block(x) + central_chunk_offset) / mcl_vars.chunksize)
+	return math.floor((coordinate_to_block(x) - central_chunk_offset) / mcl_vars.chunksize)
 end
 
 function mcl_vars.pos_to_block(pos)
@@ -70,7 +71,7 @@ function mcl_vars.pos_to_chunk(pos)
 	}
 end
 
-local k_positive = math.ceil(mcl_vars.MAX_MAP_GENERATION_LIMIT / chunk_size_in_nodes)
+local k_positive = math.ceil(mcl_vars.MAX_MAP_GENERATION_LIMIT / mcl_vars.chunk_size_in_nodes)
 local k_positive_z = k_positive * 2
 local k_positive_y = k_positive_z * k_positive_z
 

mods/CORE/mcl_worlds/init.lua

@@ -6,7 +6,7 @@ mcl_worlds = {}
 function mcl_worlds.is_in_void(pos)
 	local void =
 		not ((pos.y < mcl_vars.mg_overworld_max and pos.y > mcl_vars.mg_overworld_min) or
-		(pos.y < mcl_vars.mg_nether_max and pos.y > mcl_vars.mg_nether_min) or
+		(pos.y < mcl_vars.mg_nether_max+128 and pos.y > mcl_vars.mg_nether_min) or
 		(pos.y < mcl_vars.mg_end_max and pos.y > mcl_vars.mg_end_min))
 
 	local void_deadly = false
@@ -15,11 +15,11 @@ function mcl_worlds.is_in_void(pos)
 		-- Overworld → Void → End → Void → Nether → Void
 		if pos.y < mcl_vars.mg_overworld_min and pos.y > mcl_vars.mg_end_max then
 			void_deadly = pos.y < mcl_vars.mg_overworld_min - deadly_tolerance
-		elseif pos.y < mcl_vars.mg_end_min and pos.y > mcl_vars.mg_nether_max then
+		elseif pos.y < mcl_vars.mg_end_min and pos.y > mcl_vars.mg_nether_max+128 then
 			-- The void between End and Nether. Like usual, but here, the void
 			-- *above* the Nether also has a small tolerance area, so player
 			-- can fly above the Nether without getting hurt instantly.
-			void_deadly = (pos.y < mcl_vars.mg_end_min - deadly_tolerance) and (pos.y > mcl_vars.mg_nether_max + deadly_tolerance)
+			void_deadly = (pos.y < mcl_vars.mg_end_min - deadly_tolerance) and (pos.y > mcl_vars.mg_nether_max+128 + deadly_tolerance)
 		elseif pos.y < mcl_vars.mg_nether_min then
 			void_deadly = pos.y < mcl_vars.mg_nether_min - deadly_tolerance
 		end
@@ -35,7 +35,7 @@ end
 function mcl_worlds.y_to_layer(y)
        if y >= mcl_vars.mg_overworld_min then
                return y - mcl_vars.mg_overworld_min, "overworld"
-       elseif y >= mcl_vars.mg_nether_min and y <= mcl_vars.mg_nether_max then
+       elseif y >= mcl_vars.mg_nether_min and y <= mcl_vars.mg_nether_max+128 then
                return y - mcl_vars.mg_nether_min, "nether"
        elseif y >= mcl_vars.mg_end_min and y <= mcl_vars.mg_end_max then
                return y - mcl_vars.mg_end_min, "end"
@@ -73,7 +73,7 @@ end
 -- Takes a position and returns true if this position can have Nether dust
 function mcl_worlds.has_dust(pos)
        -- Weather in the Overworld and the high part of the void below
-       return pos.y <= mcl_vars.mg_nether_max + 64 and pos.y >= mcl_vars.mg_nether_min - 64
+       return pos.y <= mcl_vars.mg_nether_max + 138 and pos.y >= mcl_vars.mg_nether_min - 10
 end
 
 -- Takes a position (pos) and returns true if compasses are working here

mods/ENTITIES/mcl_mobs/api.lua

@@ -2826,7 +2826,7 @@ local falling = function(self, pos)
 	end
 
 	if mcl_portals ~= nil then
-		if mcl_portals.nether_portal_cooloff[self.object] then
+		if mcl_portals.nether_portal_cooloff(self.object) then
 			return false -- mob has teleported through Nether portal - it's 99% not falling
 		end
 	end

mods/ITEMS/mcl_portals/mod.conf

@@ -1,4 +1,4 @@
 name = mcl_portals
 description = Adds buildable portals to the Nether and End dimensions.
-depends = mcl_init, mcl_worlds, mcl_core, mcl_nether, mcl_end, mcl_particles, mcl_spawn
+depends = mcl_nether, mcl_end, mcl_particles, mcl_spawn
 optional_depends = awards, doc

mods/MAPGEN/mcl_mapgen_core/init.lua

@@ -29,7 +29,7 @@ local function add_chunk(pos)
 		end
 		prev = d
 	end
-	chunks[#chunks] = {n, n}
+	chunks[#chunks+1] = {n, n}
 end
 function mcl_mapgen_core.is_generated(pos)
 	local n = mcl_vars.get_chunk_number(pos) -- unsigned int
@@ -1790,6 +1790,8 @@ local generate_nether_decorations = function(minp, maxp, seed)
 		return
 	end
 
+	minetest.log("action", "[mcl_mapgen_core] Nether decorations " .. minetest.pos_to_string(minp) .. " ... " .. minetest.pos_to_string(maxp))
+
 	-- TODO: Generate everything based on Perlin noise instead of PseudoRandom
 
 	local bpos
@@ -1847,6 +1849,7 @@ local generate_nether_decorations = function(minp, maxp, seed)
 end
 
 minetest.register_on_generated(function(minp, maxp, blockseed)
+	minetest.log("action", "[mcl_mapgen_core] Generating chunk " .. minetest.pos_to_string(minp) .. " ... " .. minetest.pos_to_string(maxp))
 	add_chunk(minp)
 	local p1, p2 = {x=minp.x, y=minp.y, z=minp.z}, {x=maxp.x, y=maxp.y, z=maxp.z}
 	if lvm > 0 then
@@ -2132,24 +2135,32 @@ local function basic(vm, data, data2, emin, emax, area, minp, maxp, blockseed)
 		-- * Replace water with Nether lava.
 		-- * Replace stone, sand dirt in v6 so the Nether works in v6.
 		elseif minp.y <= mcl_vars.mg_nether_max and maxp.y >= mcl_vars.mg_nether_min then
-			local nodes
 			if mg_name == "v6" then
-				nodes = minetest.find_nodes_in_area(minp, maxp, {"mcl_core:water_source", "mcl_core:stone", "mcl_core:sand", "mcl_core:dirt"})
-			else
-				nodes = minetest.find_nodes_in_area(minp, maxp, {"mcl_core:water_source"})
-			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
-					lvm_used = true
-				elseif data[p_pos] == c_stone then
-					data[p_pos] = c_netherrack
-					lvm_used = true
-				elseif data[p_pos] == c_sand or data[p_pos] == c_dirt then
-					data[p_pos] = c_soul_sand
-					lvm_used = true
+				local nodes = minetest.find_nodes_in_area(minp, maxp, {"mcl_core:water_source", "mcl_core:stone", "mcl_core:sand", "mcl_core:dirt"})
+				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
+						lvm_used = true
+					elseif data[p_pos] == c_stone then
+						data[p_pos] = c_netherrack
+						lvm_used = true
+					elseif data[p_pos] == c_sand or data[p_pos] == c_dirt then
+						data[p_pos] = c_soul_sand
+						lvm_used = true
+					end
 				end
+			else
+				minetest.emerge_area(minp, maxp, function(blockpos, action, calls_remaining, param)
+					if calls_remaining > 0 then return end
+					-- local nodes = minetest.find_nodes_in_area(param.minp, param.maxp, {"mcl_core:water_source"})
+					local nodes = minetest.find_nodes_in_area(param.minp, param.maxp, {"group:water"})
+					local sn=(mcl_observers and mcl_observers.swap_node) or minetest.swap_node
+					local l = {name="mcl_nether:nether_lava_source"}
+					for _, n in pairs(nodes) do
+						sn(n, l)
+					end
+				end, {minp=vector.new(minp), maxp=vector.new(maxp)})
 			end
 
 		-- End block fixes:

mods/MAPGEN/mcl_structures/init.lua

@@ -534,7 +534,7 @@ end
 
 -- Debug command
 minetest.register_chatcommand("spawnstruct", {
-	params = "desert_temple | desert_well | igloo | witch_hut | boulder | ice_spike_small | ice_spike_large | fossil | end_exit_portal | end_portal_shrine | dungeon",
+	params = "desert_temple | desert_well | igloo | witch_hut | boulder | ice_spike_small | ice_spike_large | fossil | end_exit_portal | end_portal_shrine | nether_portal | dungeon",
 	description = S("Generate a pre-defined structure near your position."),
 	privs = {debug = true},
 	func = function(name, param)
@@ -570,6 +570,8 @@ minetest.register_chatcommand("spawnstruct", {
 			mcl_structures.generate_end_portal_shrine(pos, rot, pr)
 		elseif param == "dungeon" and mcl_dungeons and mcl_dungeons.spawn_dungeon then
 			mcl_dungeons.spawn_dungeon(pos, rot, pr)
+		elseif param == "nether_portal" and mcl_portals and mcl_portals.spawn_nether_portal then
+			mcl_portals.spawn_nether_portal(pos, rot, pr, name)
 		elseif param == "" then
 			message = S("Error: No structure type given. Please use “/spawnstruct <type>”.")
 			errord = true