Refucktor everything (WIP)

mods/ITEMS/mcl_core/functions.lua

@@ -48,6 +48,101 @@ minetest.register_abm({
 	end,
 })
 
+minetest.register_abm({
+	label="Speed up downwards water flow and cool lava",
+	nodenames = {"mcl_core:water_flowing"},
+	neighbors = {"air"},
+	interval = 0.5,
+	chance = 1,
+	action = function(pos, node)
+		-- I want to start with an important message to every
+		-- future programmer who wants to rewrite the code in
+		-- a recursive fashion: STACK OVERFLOWS MEAN CRASHES!
+		--
+		-- Your recursive approach will most likely crash the
+		-- game – if not on your computer, then probably some
+		-- time later on some other computer. If you want the
+		-- questionable honor of being at fault when a bucket
+		-- of water can crash the server, go ahead: Refucktor
+		-- the code and be upset when it ruins someone's day.
+		--
+		-- After all, it really was not your fault, right? On
+		-- your computer everything worked and whoever has an
+		-- issue with your elegant solution just should buy a
+		-- new gaming rig or do something else beyond holding
+		-- you responsible for your utterly perfect solution.
+		--
+		-- In case this message offends you, I hereby ask you
+		-- to kindly fuck off, by which I mean: Stop reading.
+		local beside_pos_list
+		local beside_node
+		local lavatype
+		for i=1,80 do
+			-- In the first iteration of this loop, the
+			-- current position is guaranteed to have a
+			-- flowing water node. Later iterations can
+			-- assume a flowing water node since either
+			-- this loop ends or it replaces air with a
+			-- flowing water node below, then does that
+			-- same quit-or-replace dance a node lower.
+			local below_pos = {x=pos.x, y=pos.y-i, z=pos.z}
+			local below_node = minetest.get_node(below_pos)
+			-- TODO: Check here if that node below is lava
+			-- and turn it into cobblestone or obsidian if
+			-- that process does not affect performance in
+			-- a major way. But how to measure the impact?
+			if below_node.name ~= "air" then
+				return
+			end
+			minetest.set_node(
+				below_pos,
+				{name="mcl_core:water_flowing", param2=15}
+			)
+			-- One could assume that the lava cooling ABM
+			-- would now do its job if water nodes end up
+			-- next to lava nodes. Sadly, this is not the
+			-- case: The only way to get reliable cooling
+			-- of lava nodes is to do it ourselves here …
+			-- the lava nodes are just removed otherwise.
+			--
+			-- This is probably an engine bug (not sure).
+			beside_pos_list = {
+				{x=below_pos.x+1, y=below_pos.y, z=below_pos.z},
+				{x=below_pos.x-1, y=below_pos.y, z=below_pos.z},
+				{x=below_pos.x, y=below_pos.y, z=below_pos.z+1},
+				{x=below_pos.x, y=below_pos.y, z=below_pos.z-1},
+			}
+			for _, beside_pos in ipairs(beside_pos_list) do
+				beside_node = minetest.get_node(beside_pos)
+				if 1 == minetest.get_item_group(beside_node.name, "lava") then
+					lavatype = minetest.registered_nodes[beside_node.name].liquidtype
+					-- Lava flow → Cobblestone
+					if lavatype == "flowing" then
+						minetest.set_node(
+							beside_pos,
+							{name="mcl_core:cobble"}
+						)
+					-- Lava source → Obsidian
+					elseif lavatype == "source" then
+						minetest.set_node(
+							beside_pos,
+							{name="mcl_core:obsidian"}
+						)
+					end
+					-- Stone is generated if lava
+					-- ends up above water nodes,
+					-- this is handled elsewhere.
+					minetest.sound_play(
+						"fire_extinguish_flame",
+						{pos=beside_pos, gain=0.25, max_hear_distance=16},
+						true
+					)
+				end
+			end
+		end
+	end,
+})
+
 --
 -- Papyrus and cactus growing
 --