Contents

• Functions
• Using callbacks

cWorld is the game world. It is the hub of all the information managed by individual classes, providing convenient access to them. Cuberite supports multiple worlds in any combination of world types. You can have two overworlds, three nethers etc. To enumerate all world the server provides, use the cRoot:ForEachWorld() function.

The world data is held in individual chunks. Each chunk consists of 16 (x) * 16 (z) * 256 (y) blocks, each block is specified by its block type (8-bit) and block metadata (4-bit). Additionally, each block has two light values calculated - skylight (how much daylight it receives) and blocklight (how much light from light-emissive blocks it receives), both 4-bit.

Each world runs several separate threads used for various housekeeping purposes, the most important of those is the Tick thread. This thread updates the game logic 20 times per second, and it is the thread where all the gameplay actions are evaluated. Liquid physics, entity interactions, player ovement etc., all are applied in this thread.

Additional threads include the generation thread (generates new chunks as needed, storage thread (saves and loads chunk from the disk), lighting thread (updates block light values) and the chunksender thread (compresses chunks to send to the clients).

The world provides access to all its players, entities and block entities. Because of multithreading issues, individual objects cannot be retrieved for indefinite handling, but rather must be modified in callbacks, within which they are guaranteed to stay valid.

Physics for individual blocks are handled by the simulators. These will fire in each tick for all blocks that have been scheduled for simulator update ("simulator wakeup"). The simulators include liquid physics, falling blocks, fire spreading and extinguishing and redstone.

Game time is also handled by the world. It provides the time-of-day and the total world age.

function OnChunkAvailable(ChunkX, ChunkZ)
function OnAllChunksAvailable()

function Callback(BeaconEntity)

function Callback(BlockEntity)

function Callback(cBrewingstandEntity)

function Callback(ChestEntity)

function Callback(CommandBlockEntity)

function Callback(DispenserEntity)

function Callback(DropSpenserEntity)

function Callback(DropperEntity)

function Callback(Entity)

function Callback(FlowerPotEntity)

function Callback(FurnaceEntity)

function Callback(MobHeadEntity)

function Callback(NoteEntity)

function Callback(Player)

function Callback(Player)

function Callback(Player)

function Callback(BlockEntity)

function Callback(cBrewingstandEntity)

function Callback(ChestEntity)

function Callback(Entity)

function Callback(Entity)

function Callback(Entity)

function Callback(FurnaceEntity)

function Callback(Player)

function Callback(ChunkX, ChunkZ)

function()

function(World)

Instead, the cWorld provides access to these objects using callbacks. The plugin provides a function that is called and receives the object as a parameter; cWorld guarantees that while the callback is executing, the object will stay valid. If a plugin needs to "remember" the object outside of the callback, it needs to store the entity ID, blockentity coords or player name.

The following code examples show how to use the callbacks

This code teleports player Player to another player named ToName in the same world:

-- Player is a cPlayer object
-- ToName is a string
-- World is a cWorld object
World:ForEachPlayer(
	function (a_OtherPlayer)
	if (a_OtherPlayer:GetName() == ToName) then
		Player:TeleportToEntity(a_OtherPlayer);
	end
);

This code fills each furnace in the chunk with 64 coals:

-- Player is a cPlayer object
-- World is a cWorld object
World:ForEachFurnaceInChunk(Player:GetChunkX(), Player:GetChunkZ(),
	function (a_Furnace)
		a_Furnace:SetFuelSlot(cItem(E_ITEM_COAL, 64));
	end
);

This code teleports all spiders up by 100 blocks:

-- World is a cWorld object
World:ForEachEntity(
	function (a_Entity)
		if not(a_Entity:IsMob()) then
			return;
		end

		-- Get the cMonster out of cEntity, now that we know the entity represents one.
		local Monster = tolua.cast(a_Entity, "cMonster");
		if (Monster:GetMobType() == mtSpider) then
			Monster:TeleportToCoords(Monster:GetPosX(), Monster:GetPosY() + 100, Monster:GetPosZ());
		end
	end
);