reimplement basic minecraft like fire spread

mods/ITEMS/mcl_fire/init.lua

@@ -5,29 +5,6 @@ mcl_fire = {}
 local S = minetest.get_translator("mcl_fire")
 local N = function(s) return s end
 
--- inverse pyramid pattern above lava source, floor 1 of 2:
-local lava_fire=
-{
-	{ x =-1, y = 1, z =-1},
-	{ x =-1, y = 1, z = 0},
-	{ x =-1, y = 1, z = 1},
-	{ x = 0, y = 1, z =-1},
-	{ x = 0, y = 1, z = 0},
-	{ x = 0, y = 1, z = 1},
-	{ x = 1, y = 1, z =-1},
-	{ x = 1, y = 1, z = 0},
-	{ x = 1, y = 1, z = 1}
-}
-local alldirs=
-{
-	{ x =-1, y = 0, z = 0},
-	{ x = 1, y = 0, z = 0},
-	{ x = 0, y =-1, z = 0},
-	{ x = 0, y = 1, z = 0},
-	{ x = 0, y = 0, z =-1},
-	{ x = 0, y = 0, z = 1}
-}
-
 local spawn_smoke = function(pos)
 	mcl_particles.add_node_particlespawner(pos, {
 		amount = 0.1,
@@ -359,16 +336,28 @@ minetest.register_abm({
 
 -- Enable the following ABMs according to 'enable fire' setting
 
+-- [...]a fire that is not adjacent to any flammable block does not spread, even to another flammable block within the normal range.
+-- https://minecraft.fandom.com/wiki/Fire#Spread
+
 local function has_flammable(pos)
-	local npos, node
+	return minetest.find_node_near(pos, 1, {"group:flammable"})
-	for n, v in ipairs(alldirs) do
+end
-		npos = vector.add(pos, v)
+
-		node = minetest.get_node_or_nil(npos)
+local function check_aircube(p1,p2)
-		if node and node.name and minetest.get_item_group(node.name, "flammable") ~= 0 then
+	local nds=minetest.find_nodes_in_area(p1,p2,{"air"})
-			return npos
+	for k,v in pairs(nds) do
-		end
+		if has_flammable(v) then return v end
 	end
-	return false
+end
+
+
+-- [...] a fire block can turn any air block that is adjacent to a flammable block into a fire block. This can happen at a distance of up to one block downward, one block sideways (including diagonals), and four blocks upward of the original fire block (not the block the fire is on/next to).
+local function get_ignitable(pos)
+	return check_aircube(vector.add(pos,vector.new(-1,-1,-1)),vector.add(pos,vector.new(1,4,1))) 
+end
+-- Fire spreads from a still lava block similarly: any air block one above and up to one block sideways (including diagonals) or two above and two blocks sideways (including diagonals) that is adjacent to a flammable block may be turned into a fire block.
+local function get_ignitable_by_lava(pos)
+	return check_aircube(vector.add(pos,vector.new(-1,1,-1)),vector.add(pos,vector.new(1,1,1))) or check_aircube(vector.add(pos,vector.new(-2,2,-2)),vector.add(pos,vector.new(2,2,2))) or nil
 end
 
 if not fire_enabled then
@@ -386,78 +375,37 @@ if not fire_enabled then
 
 else -- Fire enabled
 
-	-- Set fire to air nodes
+	-- Fire Spread
-	minetest.register_abm({
-		label = "Ignite fire by lava",
-		nodenames = {"group:lava"},
-		neighbors = {"air"},
-		interval = 7,
-		chance = 3,
-		catch_up = false,
-		action = function(pos)
-			local i, dir, target, node, i2, f
-			i = math.random(1,9)
-			dir = lava_fire[i]
-			target = {x=pos.x+dir.x, y=pos.y+dir.y, z=pos.z+dir.z}
-			node = minetest.get_node(target)
-			if not node or node.name ~= "air" then
-				i = ((i + math.random(0,7)) % 9) + 1
-				dir = lava_fire[i]
-				target = {x=pos.x+dir.x, y=pos.y+dir.y, z=pos.z+dir.z}
-				node = minetest.get_node(target)
-				if not node or node.name ~= "air" then
-					return
-				end
-			end
-			i2 = math.random(1,15)
-			if i2 < 10 then
-				local dir2, target2, node2
-				dir2 = lava_fire[i2]
-				target2 = {x=target.x+dir2.x, y=target.y+dir2.y, z=target.z+dir2.z}
-				node2 = minetest.get_node(target2)
-				if node2 and node2.name == "air" then
-					f = has_flammable(target2)
-					if f then
-						minetest.after(1, spawn_fire, {x=target2.x, y=target2.y, z=target2.z})
-						minetest.add_particle({
-							pos = vector.new({x=pos.x, y=pos.y+0.5, z=pos.z}),
-							velocity={x=f.x-pos.x, y=math.max(f.y-pos.y,0.7), z=f.z-pos.z},
-							expirationtime=1, size=1.5, collisiondetection=false,
-							glow=minetest.LIGHT_MAX, texture="mcl_particles_flame.png"
-						})
-						return
-					end
-				end
-			end
-			f = has_flammable(target)
-			if f then
-				minetest.after(1, spawn_fire, {x=target.x, y=target.y, z=target.z})
-				minetest.add_particle({
-					pos = vector.new({x=pos.x, y=pos.y+0.5, z=pos.z}),
-					velocity={x=f.x-pos.x, y=math.max(f.y-pos.y,0.25), z=f.z-pos.z},
-					expirationtime=1, size=1, collisiondetection=false,
-					glow=minetest.LIGHT_MAX, texture="mcl_particles_flame.png"
-				})
-			end
-		end,
-	})
-
-	-- Ignite neighboring nodes, add basic flames
 	minetest.register_abm({
 		label = "Ignite flame",
-		nodenames = {"group:flammable"},
+		nodenames ={"mcl_fire:fire","mcl_fire:eternal_fire"},
-		neighbors = {"mcl_fire:fire","mcl_fire:eternal_fire","mcl_core:lava_source","mcl_core:lava_flowing","mcl_nether:nether_lava_source","mcl_nether:nether_lava_flowing",},
 		interval = 7,
 		chance = 12,
 		catch_up = false,
 		action = function(pos)
-			local p = minetest.find_node_near(pos, 1, {"air"})
+			local p = get_ignitable(pos)
 			if p then
 				minetest.set_node(p, {name = "mcl_fire:fire"})
 			end
 		end
 	})
 
+	--lava fire spread
+	minetest.register_abm({
+		label = "Ignite fire by lava",
+		nodenames = {"mcl_core:lava_source","mcl_nether:nether_lava_source"},
+		neighbors = {"air","group:flammable"},
+		interval = 7,
+		chance = 3,
+		catch_up = false,
+		action = function(pos)
+			local p=get_ignitable_by_lava(pos)
+			if p then
+				minetest.set_node(p, {name = "mcl_fire:fire"})
+			end
+		end,
+	})
+
 	-- Remove flammable nodes around basic flame
 	minetest.register_abm({
 		label = "Remove flammable nodes",