Conceitos
Propriedades
All blocks are of a base type. Examples of base types include redstone dust, brick stairs, and chest. However, to further differentiate these base types, each block has set of different properties, of which each can take a limited set of values (i.e. activated redstone, corner brick stairs, double chest). A block can have multiple properties (such as corner,*upsidedown* stairs).
Examples of block properties
minecraft:dirt[snowy=false,variant=default] minecraft:dirt[snowy=true,variant=default] minecraft:dirt[snowy=false,variant=grassless] minecraft:dirt[snowy=true,variant=grassless] minecraft:redstone_wire[east=up,north=up,power=0,south=up,west=up] minecraft:redstone_wire[east=side,north=up,power=0,south=up,west=up] minecraft:redstone_wire[east=none,north=up,power=0,south=up,west=up] minecraft:redstone_wire[east=up,north=side,power=0,south=up,west=up]
Algumas propriedades, no entanto, são efémeras – só existem durante a execução do jogo. Os valores destas propriedades não são escritos no ficheiro porque podem ser detetados automaticamente. Por exemplo, no caso de um fio de redstone, o estar ligado ou não pode ser detetado com base no ambiente (há alguma alavanca que esteja ligada?). Neste caso, a propriedade power de minecraft:redstone_wire, como demonstrado acima, é uma propriedade efémera.
Each property will have a finite number of valid values that can be assigned to the property. Exampeles would be that redstone power can only be a value between 0 and 15. This means that Minecraft knows each possible state of a block prior to fully booting the server. This is required knowledge as sending blocks over the network are compressed to a number.
Block Entity Data
With block properties having a known preset of possible values, these cannot be used when attempting to store data whereby there is a infinite amount of possibilities. Examples include sign text and block inventories.
Minecraft’s solution to this is block entities, which are Java objects that store additional data on a Location the block is at in NBT format. Examples of block entities are Chest
Example use would be to receive the inventory of a chest. This can be done as follows
import org.spongepowered.api.world.server.ServerLocation;
import org.spongepowered.api.block.entity.BlockEntity;
import org.spongepowered.api.block.entity.carrier.chest.Chest;
import org.spongepowered.api.item.inventory.type.BlockEntityInventory;
public Optional<BlockEntityInventory<Chest>> getChestInventory(ServerLocation location){
Optional<BlockEntity> optionalBlockEntity = location.blockEntity();
if(optionalBlockEntity.isPresent()){
BlockEntity blockEntity = optionalBlockEntity.get();
if(blockEntity instanceof Chest){
Chest chest = (Chest) blockEntity;
return Optional.of(chest.inventory());
}
}
return Optional.empty();
}
Dica
Algumas coisas, tais como pinturas, são na realidade entidades.
No entanto, as tile entities também podem alterar o rendering para não se parecerem com um bloco normal, apesar de isto ser geralmente ineficiente e causar uma queda na taxa de frames do cliente.
