mod-sneeker/spawn.lua

-- Original code by Rui: WTFPL


local time_min = 60
local time_hr = time_min * 60
local time_day = time_hr * 24

local spawn_cap = tonumber(core.settings:get('sneeker.spawn_cap')) or 10 -- Maximum number of spawns active at one time
local spawn_chance = tonumber(core.settings:get('sneeker.spawn_chance')) or 1000 -- 1/1000 chance of spawn
local spawn_interval = tonumber(core.settings:get('sneeker.spawn_interval')) or time_min * 4 -- Default interval is 4 minutes
local spawn_maxlight = tonumber(core.settings:get('sneeker.spawn_maxlight')) or 5 -- Maximum light of node for spawn

-- Display spawn chance as percentage in log
local spawn_chance_percent = math.floor(1 / spawn_chance * 100)
if spawn_chance_percent < 1 then
	spawn_chance_percent = 'Less than 1%'
else
	spawn_chance_percent = tostring(spawn_chance_percent) .. '%'
end

sneeker.log('Spawn cap: ' .. tostring(spawn_cap))
sneeker.log('Spawn chance: ' .. spawn_chance_percent)
sneeker.log('Spawn interval: ' .. tostring(spawn_interval) .. ' (' .. tostring(spawn_interval/60) .. ' minute(s))')
sneeker.log('Maximum light value for spawn: ' .. tostring(spawn_maxlight))


if core.global_exists('mobs') then
	mobs:spawn({
		name = sneeker.mob_name,
		nodes = {'default:dirt_with_grass', 'default:stone'},
		neighbors = {'air'},
		min_light = -1,
		max_light = spawn_maxlight,
		interval = spawn_interval,
		chance = spawn_chance,
	})
	
	mobs:register_egg(sneeker.mob_name, 'Sneeker Spawn Egg', 'sneeker_spawnegg.png', 0, false)
else
	core.register_abm({
		nodenames = {'default:dirt_with_grass', 'default:stone'},
		neighbors = {'air'},
		interval = spawn_interval,
		chance = spawn_chance,
		action = function(pos, node, _, active_object_count_wider)
			if active_object_count_wider > 5 then
				return
			end
			
			-- Check light value of node
			pos.y = pos.y+1
			local node_light = core.get_node_light(pos)
			
			-- Debugging spawning
			sneeker.log_debug('Node light level at ' .. sneeker.get_pos_string(pos) .. ': ' .. tostring(node_light))
			
			if not node_light or node_light > spawn_maxlight or node_light < -1 then
				sneeker.log_debug('Node not dark enough for spawn')
				return
			end
			
			-- Spawn range
			if pos.y > 31000 then
				return
			end
			
			-- Node must be touching air
			if core.get_node(pos).name ~= 'air' then
				return
			end
			pos.y = pos.y+1
			if core.get_node(pos).name ~= 'air' then
				return
			end
			
			-- Get total count of sneekers in world
			local count = 0
			for I in pairs(core.luaentities) do
			    if core.luaentities[I].name == sneeker.mob_name then
			        count = count + 1
			    end
			end
			
			sneeker.log_debug('Current active spawns: ' .. tostring(count) .. '/' .. tostring(spawn_cap))
			
			if count >= spawn_cap then
				sneeker.log_debug('Max spawns reached')
				return
			end
			
			sneeker.spawn(pos)
		end
	})
	
	
	if core.get_modpath('spawneggs') and core.get_modpath('tnt') then
		core.register_craftitem(sneeker.spawnegg_name, {
			description = 'Sneeker Spawn Egg',
			inventory_image = 'sneeker_spawnegg.png',
			on_place = function(itemstack, placer, pointed_thing)
				if pointed_thing.type == 'node' then
					local pos = pointed_thing.above
					pos.y = pos.y+1
					core.add_entity(pos, sneeker.mob_name)
					if not core.settings:get_bool('creative_mode') then
						itemstack:take_item()
					end
					return itemstack
				end
			end
		})
		
		core.register_craft({
			output = sneeker.spawnegg_name,
			type = 'shapeless',
			recipe = {
				'spawneggs:egg', 'tnt:tnt',
			},
		})
		
		core.register_alias('spawneggs:sneeker', sneeker.spawnegg_name)
	end
end