Registering and using configured/placed features in Forge for Minecraft 1.18.2

FeatureExampleMod.java

package commoble.featureexamplemod;

import java.util.List;

import net.minecraft.core.Registry;
import net.minecraft.data.worldgen.placement.PlacementUtils;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.levelgen.GenerationStep.Decoration;
import net.minecraft.world.level.levelgen.feature.ConfiguredFeature;
import net.minecraft.world.level.levelgen.feature.Feature;
import net.minecraft.world.level.levelgen.feature.configurations.BlockPileConfiguration;
import net.minecraft.world.level.levelgen.feature.stateproviders.BlockStateProvider;
import net.minecraft.world.level.levelgen.placement.InSquarePlacement;
import net.minecraft.world.level.levelgen.placement.PlacedFeature;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.event.world.BiomeLoadingEvent;
import net.minecraftforge.eventbus.api.IEventBus;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
import net.minecraftforge.registries.DeferredRegister;
import net.minecraftforge.registries.RegistryObject;

@Mod(FeatureExampleMod.MODID)
public class FeatureExampleMod
{
	public static final String MODID = "featureexample";
	
	private static final DeferredRegister<ConfiguredFeature<?,?>> CONFIGURED_FEATURES =
		DeferredRegister.create(Registry.CONFIGURED_FEATURE_REGISTRY, MODID);
	public static final DeferredRegister<PlacedFeature> PLACED_FEATURES =
		DeferredRegister.create(Registry.PLACED_FEATURE_REGISTRY, MODID);
	
	private static final String TNT_PILE_NAME = "tnt_pile";
	
	// your ConfiguredFeature RegistryObject fields must use <?,?> as the generic params for technical reasons
	private static final RegistryObject<ConfiguredFeature<?,?>> CONFIGURED_TNT_PILE =
		CONFIGURED_FEATURES.register(TNT_PILE_NAME,
			// ConfiguredFeature takes a feature type and a featureconfig.
			// You generally can't static init featureconfigs ahead of time, as they
			// very often have hard references to blocks (such as this one does).
			// The feature type defines the generation logic, the feature config is extra data used by that logic.
			// Feature.BLOCK_PILE generates blocks in a pile, it takes a BlockPileConfiguration.
			() -> new ConfiguredFeature<>(Feature.BLOCK_PILE,
				// BlockPileConfiguration takes a blockstate provider, we use one that always provides TNT.
				new BlockPileConfiguration(BlockStateProvider.simple(Blocks.TNT))));
	
	// A PlacedFeature is a configured feature and a list of placement modifiers.
	// This is what goes into biomes, the placement modifiers determine where and how often to
	// place the configured feature.
	// Each placed feature in any of the biomes in a chunk generates in that chunk when the chunk generates.
	// When a feature generates in a chunk, the chunk's local 0,0,0 origin coordinate is given to the
	// list of placement modifiers (if any).
	// Each placement modifier converts the input position to zero or more output positions, each of which
	// is given to the next placement modifier.
	// The ConfiguredFeature is generated at the positions generated after all placement modifiers have run.
	private static final RegistryObject<PlacedFeature> PLACED_TNT_PILE =
		PLACED_FEATURES.register(TNT_PILE_NAME, 
			() -> new PlacedFeature(CONFIGURED_TNT_PILE.getHolder().get(),
				// InSquarePlacement.spread() takes the input position
				// and randomizes the X and Z coordinates within the chunk
				// PlacementUtils.HEIGHTMAP sets the Y-coordinate of the input position to the heightmap.
				// This causes the tnt pile to be generated at a random surface position in the chunk.
				List.of(InSquarePlacement.spread(), PlacementUtils.HEIGHTMAP)));
	
	public FeatureExampleMod()
	{
		IEventBus modBus = FMLJavaModLoadingContext.get().getModEventBus();
		IEventBus forgeBus = MinecraftForge.EVENT_BUS;
		
		CONFIGURED_FEATURES.register(modBus);
		PLACED_FEATURES.register(modBus);
		
		forgeBus.addListener(this::onBiomeLoading);
	}
	
	// BiomeLoadingEvent can be used to add placed features to existing biomes.
	// Placed features added in the BiomeLoadingEvent must have been previously registered.
	// JSON features cannot be added to biomes via the BiomeLoadingEvent.
	private void onBiomeLoading(BiomeLoadingEvent event)
	{
		event.getGeneration().addFeature(Decoration.VEGETAL_DECORATION, PLACED_TNT_PILE.getHolder().get());
	}
}