[1.14.4] LootCondition

[Simon_kungen]

Hi

 

I needed a way to check if a block was destroyed by an explosion or not, but I might have more uses with this if I make it more generic, as in checking if the block has been removed by  a certain thing such as a player or a Enderman, or by an explosion.

 

DestroyedBy:java

Spoiler

public class DestroyedBy implements ILootCondition
{

    private final String destroyer;

    private DestroyedBy(String destroyer)
    {
        this.destroyer = destroyer;
    }


    //public static final DestroyedBy INSTANCE = new DestroyedBy();


    @Override
    public boolean test(LootContext lootContext)
    {
        //System.out.println(destroyer);


        return false;

    }


    public static class Serializer extends ILootCondition.AbstractSerializer<DestroyedBy>
    {

        public Serializer()
        {
            super(new ResourceLocation(Reference.MODID,"destroyed_by"),DestroyedBy.class);
        }

        @Override
        public void serialize(JsonObject json, DestroyedBy value, JsonSerializationContext context)
        {
            json.addProperty("destroyer",value.destroyer);
        }

        @Override
        public DestroyedBy deserialize(JsonObject json, JsonDeserializationContext context)
        {
            return new DestroyedBy(json.has("destroyer") ? JSONUtils.getString(json,"destroyer") : "minecraft:player");
        }
    }
}

 

 

 

How do I get what destroyed a block?

[Draco18s]

I'd say "have you looked at the LootContext object?" but I realize that it's not quite that straight forward.

You need to look at how they're created and what parameters get passed. What you're looking for here are the LootParameter objects, conveniently all enumerated in the LootParameters class. And one is called EXPLOSION_RADIUS.

 

If that parameter exists, the block was destroyed by an explosion, if not then no.

 

LootParameters.THIS_ENTITY will be the parameter that holds a reference to the player (if there is one, and may also be null) and LootParameters.TOOL will have the tool used (may be empty even when a player breaks a block).

Edited September 4, 2019 by Draco18s

[Draco18s]

Oof. I tried.

[Simon_kungen]

I did a kind of clunky solution to this:

 

switch (destroyer) {
    case "minecraft:explosion": {

        if (lootContext.get(LootParameters.THIS_ENTITY) == null) {
            System.out.println("It was a explosion (probably)!");
            return true;
        }
        break;

    }

    case "minecraft:player": {
        if (lootContext.get(LootParameters.THIS_ENTITY) instanceof PlayerEntity) {
            System.out.println("It's a player!");
            return true;
        }
        break;
    }
}

 

I simply went by extermination method narrowing it down until I'm pretty sure I know what it is. Something I noticed was that I have no way of checking if it was destroyed from the fill command or an explosion.

My second idea is to check in a 3x3 block radius after an explosion. What is that smoke effect? A temporary entity or something else?

 

But at this point, this feels like its getting far too complicated than it needs to be. The plan was to when Cobblestone explodes there is a chance for it to drop Gravel instead, and then blowing up Gravel can turn it into Sand. I did this function first, but I got stuck as there is no way of changing what a block drops, so I changed the blocks right before they blew up, too short for us to notice, but gets the effect of some of it turning into Gravel/Sand.

 

public static void onExplosion(final ExplosionEvent event)
{
    Random random = new Random();

    if (!event.getWorld().isRemote) {
        for (BlockPos pos : event.getExplosion().getAffectedBlockPositions()) {
            Block block = event.getWorld().getBlockState(pos).getBlock();

            if (BlockTags.getCollection().getOrCreate(cobblestoneID).contains(block)) {

                if (random.nextInt(9) == 0)
                    event.getWorld().setBlockState(pos, Blocks.GRAVEL.getDefaultState());

            } else if (BlockTags.getCollection().getOrCreate(gravelID).contains(block)) {
                if (random.nextInt(9) == 0)
                    event.getWorld().setBlockState(pos, Blocks.SAND.getDefaultState());
            }
        }
    }

}

 

But then there is the problem of some of the Gravel turning into Flint, which isn't supposed to happen.

[Simon_kungen]

I ended up with this solution and created two new blocks just as a temporary block placement.

 

public static void onExplosion(final ExplosionEvent event)
{
    Random random = new Random();

    if (!event.getWorld().isRemote) {
        for (BlockPos pos : event.getExplosion().getAffectedBlockPositions()) {
            Block block = event.getWorld().getBlockState(pos).getBlock();

            if (BlockTags.getCollection().getOrCreate(cobblestoneID).contains(block)) {
                if (random.nextInt(9) == 0) {
                    if (random.nextInt(9) == 0)
                        event.getWorld().setBlockState(pos, IntercraftBlocks.SANDSUBSTITUTE.getDefaultState());
                    else
                        event.getWorld().setBlockState(pos, IntercraftBlocks.GRAVELSUBSTITUTE.getDefaultState());
                }


            } else if (BlockTags.getCollection().getOrCreate(gravelID).contains(block)) {
                if (random.nextInt(9) == 0) {
                    event.getWorld().setBlockState(pos, IntercraftBlocks.SANDSUBSTITUTE.getDefaultState());
                } else {
                    event.getWorld().setBlockState(pos, IntercraftBlocks.GRAVELSUBSTITUTE.getDefaultState());
                }
            }
        }
    }
}

 

I then did a generic loot table drop where it drops the vanilla variant. Something I was wondering though is how I would make this hardcoded drop value to be in JSON format? n% chance for this drop, and otherwise this drop instead. The only thing I found was the looting and fortune functions, but those only apply if broken with a tool. Do I have to make my own function for that? Because I would prefer doing it all in JSON format if it's possible.