mod-sneeker/spawn.lua

local spawn_nodes = {}
if sneeker.spawn_nodes ~= "" then
	if not sneeker.spawn_nodes:find(",") then
		table.insert(spawn_nodes, sneeker.spawn_nodes)
	else
		for _, node in ipairs(sneeker.spawn_nodes:split(",")) do
			local node = node:trim()
			if node ~= "" then
				table.insert(spawn_nodes, node)
			end
		end
	end
end

if #spawn_nodes == 0 then
	sneeker.log("warning", "no spawning nodes set, cannot spawn")
end


core.register_abm({
	nodenames = spawn_nodes,
	neighbors = {"air"},
	interval = sneeker.spawn_interval,
	chance = sneeker.spawn_chance,
	action = function(pos, node, aoc, aocw)
		if aoc >= sneeker.spawn_mapblock_limit then return end

		-- check above target node
		pos.y = pos.y+1

		local pos_string = tostring(math.floor(pos.x))
			.. "," .. tostring(math.floor(pos.y))
			.. "," .. tostring(math.floor(pos.z))

		if sneeker.spawn_require_player_nearby then
			local player_nearby = false
			for _, entity in ipairs(core.get_objects_inside_radius(pos, sneeker.spawn_player_radius)) do
				if entity:is_player() then
					player_nearby = true
					break
				end
			end

			if not player_nearby then return end
		end

		if pos.y > sneeker.spawn_maxheight or pos.y < sneeker.spawn_minheight then
			return
		end

		-- needs two vertical air nodes to spawn
		for _, node_pos in ipairs({pos, {x=pos.x, y=pos.y+1, z=pos.z}}) do
			if core.get_node(node_pos).name ~= "air" then
				return
			end
		end

		local llevel = core.get_node_light(pos)
		if not llevel or llevel > sneeker.spawn_maxlight or llevel < sneeker.spawn_minlight then
			return
		end

		local spawned = core.add_entity(pos, "sneeker:sneeker")
		if not spawned then
			sneeker.log("warning", "Failed to spawn at: " .. pos_string)
		else
			sneeker.log("debug", "Spawned at: " .. pos_string)
		end
	end
})