[1.16] Attach Capability to Chunks?

[kiou.23]

Say I simply want to hold a single random Integer in each chunk, I know I can attach Capabilities to Chunks through the  AttachcapabilitiesEvent, but then I would need to create my own class that extends Capability<Integer>? Would I need to serialize the data to nbt for it to be saved? any tips on how I should go about doing this?

[Draco18s]

No, you would create your own class that implements MySavedIntegerStorage<MySavedIntegerInterface>

 

https://github.com/Draco18s/ReasonableRealism/blob/1.12.1/src/main/java/com/draco18s/farming/entities/capabilities/MilkStorage.java

Edited December 1, 2020 by Draco18s

[kiou.23]

30 minutes ago, Draco18s said:

No, you would create your own class that implements MySavedIntegerStorage<MySavedIntegerInterface>

 

https://github.com/Draco18s/ReasonableRealism/blob/1.12.1/src/main/java/com/draco18s/farming/entities/capabilities/MilkStorage.java

Okay, like this?

public interface IChunkValue {

    int getValue();
    void setValue(int value);

}

 

public class ChunkValue implements IChunkValue {

    private int value;

    public ChunkValue(int value) {
        this.value = value;
    }

    @Override
    public int getValue() {
        return value;
    }

    @Override
    public void setValue(int value) {
        this.value = value;
    }
}

 

public class ChunkValueStorage implements Capability.IStorage<IChunkValue> {

    @Override
    public INBT writeNBT(Capability<IChunkValue> capability, IChunkValue instance, Direction side) {
        CompoundNBT nbt = new CompoundNBT();
        nbt.putInt("value", instance.getValue());
        return nbt;
    }

    @Override
    public void readNBT(Capability<IChunkValue> capability, IChunkValue instance, Direction side, INBT nbt) {
        instance.setValue(((CompoundNBT)nbt).getInt("value"));
    }

    public class Factory implements Callable<IChunkValue> {
        @Override
        public IChunkValue call() throws Exception {
            return new ChunkValue(0);
        }
    }
}

 

Now what?... I don't really get where to go after this

[Draco18s]

https://github.com/Draco18s/ReasonableRealism/blob/1.12.1/src/main/java/com/draco18s/farming/FarmingBase.java#L86-L87

 

Pretty sure this hasn't changed.

[kiou.23]

13 minutes ago, Draco18s said:

https://github.com/Draco18s/ReasonableRealism/blob/1.12.1/src/main/java/com/draco18s/farming/FarmingBase.java#L86-L87

 

Pretty sure this hasn't changed.

yeah, I did that, but I'm getting a bunch of NullPointerExceptions at this line:

    @Override
    public INBT serializeNBT() {
        return TutorialMod.CHUNK_VALUE_CAPABILITY.writeNBT(getCachedChunkValue(), null);
    }

 

I'm guessing that it's because I'm defining TutorialMod.CHUNK_VALUE_CAPABILITY as null, but I don't know what to do then

 

    @CapabilityInject(IChunkValue.class)
    public static final Capability<IChunkValue> CHUNK_VALUE_CAPABILITY = null;

 

should I initialise it as something else?

[Draco18s]

1 minute ago, kiou.23 said:

should I initialise it as something else?

No, that's how its supposed to work. Forge injects the value to non-null at runtime.

You still need to register the capability.

https://github.com/Draco18s/ReasonableRealism/blob/1.12.1/src/main/java/com/draco18s/farming/FarmingBase.java#L189

[kiou.23]

22 minutes ago, Draco18s said:

No, that's how its supposed to work. Forge injects the value to non-null at runtime.

You still need to register the capability.

https://github.com/Draco18s/ReasonableRealism/blob/1.12.1/src/main/java/com/draco18s/farming/FarmingBase.java#L189

OHH that is what I was missing, thanks!

just a final question tho, why do I need an interface? if it's only going to be implemented once, why can't I just reference the class (in this case, ChunkValue)?

Edited December 1, 2020 by kiou.23

[Draco18s]

Because of how Capabilities work.

[vemerion]

1 hour ago, kiou.23 said:

just a final question tho, why do I need an interface? if it's only going to be implemented once, why can't I just reference the class (in this case, ChunkValue)?

You don't need an interface, you could use the ChunkValue class only, without an interface.

[kiou.23]

12 hours ago, Draco18s said:

Because of how Capabilities work.

 

11 hours ago, vemerion said:

You don't need an interface, you could use the ChunkValue class only, without an interface.

 

who do I trust?

[diesieben07]

2 minutes ago, kiou.23 said:

who do I trust?

vemerion is right

[desht]

Expanding on this:

• If you intend for your capability to ever be used by other mods (i.e. you're making it part of your mod's API) then using an interface is very strongly advised, simply as good programming practice (expose the interface, not the implementation).
• If you only ever intend for your capability to be used for storing data for your own purposes, an interface is very much optional.  You might decide it's useful to have one, just for tidiness in your own code, but then again you're free just to use a class.