Restored the state of the biome api to what it was during the snapshots. Migrated from accessors to AWs. (#1834)

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/api/biome/v1/BiomeModificationContext.java

@@ -21,6 +21,7 @@ import java.util.function.BiPredicate;
 
 import org.jetbrains.annotations.NotNull;
 
+import net.minecraft.world.gen.feature.PlacedFeature;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.SpawnGroup;
 import net.minecraft.sound.BiomeAdditionsSound;
@@ -35,7 +36,6 @@ import net.minecraft.world.biome.BiomeParticleConfig;
 import net.minecraft.world.biome.SpawnSettings;
 import net.minecraft.world.gen.GenerationStep;
 import net.minecraft.world.gen.carver.ConfiguredCarver;
-import net.minecraft.world.gen.feature.ConfiguredFeature;
 import net.minecraft.world.gen.feature.ConfiguredStructureFeature;
 import net.minecraft.world.gen.feature.StructureFeature;
 
@@ -288,16 +288,16 @@ public interface BiomeModificationContext {
 		/**
 		 * Removes a feature from one of this biomes generation steps, and returns if any features were removed.
 		 */
-		boolean removeFeature(GenerationStep.Feature step, RegistryKey<ConfiguredFeature<?, ?>> configuredFeatureKey);
+		boolean removeFeature(GenerationStep.Feature step, RegistryKey<PlacedFeature> placedFeatureKey);
 
 		/**
 		 * Removes a feature from all of this biomes generation steps, and returns if any features were removed.
 		 */
-		default boolean removeFeature(RegistryKey<ConfiguredFeature<?, ?>> configuredFeatureKey) {
+		default boolean removeFeature(RegistryKey<PlacedFeature> placedFeatureKey) {
 			boolean anyFound = false;
 
 			for (GenerationStep.Feature step : GenerationStep.Feature.values()) {
-				if (removeFeature(step, configuredFeatureKey)) {
+				if (removeFeature(step, placedFeatureKey)) {
 					anyFound = true;
 				}
 			}
@@ -306,34 +306,37 @@ public interface BiomeModificationContext {
 		}
 
 		/**
-		 * {@link #removeFeature(RegistryKey)} for built-in features (see {@link #addBuiltInFeature(GenerationStep.Feature, ConfiguredFeature)}).
+		 * {@link #removeFeature(RegistryKey)} for built-in features (see {@link #addBuiltInFeature(GenerationStep.Feature, PlacedFeature)}).
 		 */
-		default boolean removeBuiltInFeature(ConfiguredFeature<?, ?> configuredFeature) {
-			return removeFeature(BuiltInRegistryKeys.get(configuredFeature));
+		default boolean removeBuiltInFeature(PlacedFeature placedFeature) {
+			return removeFeature(BuiltInRegistryKeys.get(placedFeature));
 		}
 
 		/**
-		 * {@link #removeFeature(GenerationStep.Feature, RegistryKey)} for built-in features (see {@link #addBuiltInFeature(GenerationStep.Feature, ConfiguredFeature)}).
+		 * {@link #removeFeature(GenerationStep.Feature, RegistryKey)} for built-in features (see {@link #addBuiltInFeature(GenerationStep.Feature, PlacedFeature)}).
 		 */
-		default boolean removeBuiltInFeature(GenerationStep.Feature step, ConfiguredFeature<?, ?> configuredFeature) {
-			return removeFeature(step, BuiltInRegistryKeys.get(configuredFeature));
+		default boolean removeBuiltInFeature(GenerationStep.Feature step, PlacedFeature placedFeature) {
+			return removeFeature(step, BuiltInRegistryKeys.get(placedFeature));
 		}
 
 		/**
-		 * Adds a feature to one of this biomes generation steps, identified by the configured feature's registry key.
+		 * Adds a feature to one of this biomes generation steps, identified by the placed feature's registry key.
+		 *
+		 * @see BuiltinRegistries#PLACED_FEATURE
 		 */
-		void addFeature(GenerationStep.Feature step, RegistryKey<ConfiguredFeature<?, ?>> configuredFeatureKey);
+		void addFeature(GenerationStep.Feature step, RegistryKey<PlacedFeature> placedFeatureKey);
 
 		/**
-		 * Adds a configured feature from {@link BuiltinRegistries#CONFIGURED_FEATURE} to this biome.
+		 * Adds a placed feature from {@link BuiltinRegistries#PLACED_FEATURE} to this biome.
 		 *
-		 * <p>This method is intended for use with the configured features found in {@link net.minecraft.world.gen.feature.ConfiguredFeatures}.
+		 * <p>This method is intended for use with the placed features found in
+		 * classes such as {@link net.minecraft.world.gen.feature.OrePlacedFeatures}.
 		 *
-		 * <p><b>NOTE:</b> In case the configured feature is overridden in a datapack, the datapacks version
+		 * <p><b>NOTE:</b> In case the placed feature is overridden in a datapack, the datapacks version
 		 * will be used.
 		 */
-		default void addBuiltInFeature(GenerationStep.Feature step, ConfiguredFeature<?, ?> configuredFeature) {
-			addFeature(step, BuiltInRegistryKeys.get(configuredFeature));
+		default void addBuiltInFeature(GenerationStep.Feature step, PlacedFeature placedFeature) {
+			addFeature(step, BuiltInRegistryKeys.get(placedFeature));
 		}
 
 		/**
@@ -401,7 +404,7 @@ public interface BiomeModificationContext {
 		 * <p>Configured structures that have the same underlying {@link StructureFeature} as the given structure will be removed before
 		 * adding the new structure, since only one of them could actually generate.
 		 *
-		 * @see net.minecraft.world.biome.GenerationSettings.Builder#structureFeature(ConfiguredStructureFeature)
+		 * @see net.minecraft.world.biome.GenerationSettings.Builder#feature(GenerationStep.Feature, PlacedFeature)
 		 */
 		void addStructure(RegistryKey<ConfiguredStructureFeature<?, ?>> configuredStructureKey);
 
@@ -473,7 +476,7 @@ public interface BiomeModificationContext {
 		/**
 		 * Associated JSON property: <code>spawners</code>.
 		 *
-		 * @see SpawnSettings#getSpawnEntry(SpawnGroup)
+		 * @see SpawnSettings#getSpawnEntries(SpawnGroup)
 		 * @see SpawnSettings.Builder#spawn(SpawnGroup, SpawnSettings.SpawnEntry)
 		 */
 		void addSpawn(SpawnGroup spawnGroup, SpawnSettings.SpawnEntry spawnEntry);

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/api/biome/v1/BiomeModifications.java

@@ -20,6 +20,7 @@ import java.util.function.Predicate;
 
 import com.google.common.base.Preconditions;
 
+import net.minecraft.world.gen.feature.PlacedFeature;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.SpawnGroup;
 import net.minecraft.util.Identifier;
@@ -28,7 +29,6 @@ import net.minecraft.util.registry.RegistryKey;
 import net.minecraft.world.biome.SpawnSettings;
 import net.minecraft.world.gen.GenerationStep;
 import net.minecraft.world.gen.carver.ConfiguredCarver;
-import net.minecraft.world.gen.feature.ConfiguredFeature;
 import net.minecraft.world.gen.feature.ConfiguredStructureFeature;
 
 /**
@@ -45,7 +45,7 @@ public final class BiomeModifications {
 	 *
 	 * @see BiomeSelectors
 	 */
-	public static void addFeature(Predicate<BiomeSelectionContext> biomeSelector, GenerationStep.Feature step, RegistryKey<ConfiguredFeature<?, ?>> configuredFeatureKey) {
+	public static void addFeature(Predicate<BiomeSelectionContext> biomeSelector, GenerationStep.Feature step, RegistryKey<PlacedFeature> configuredFeatureKey) {
 		create(configuredFeatureKey.getValue()).add(ModificationPhase.ADDITIONS, biomeSelector, context -> {
 			context.getGenerationSettings().addFeature(step, configuredFeatureKey);
 		});

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/api/biome/v1/BiomeSelectionContext.java

@@ -20,6 +20,7 @@ import java.util.List;
 import java.util.Optional;
 import java.util.function.Supplier;
 
+import net.minecraft.world.gen.feature.PlacedFeature;
 import net.minecraft.util.registry.RegistryKey;
 import net.minecraft.world.biome.Biome;
 import net.minecraft.world.gen.feature.ConfiguredFeature;
@@ -44,7 +45,8 @@ public interface BiomeSelectionContext {
 	 * Returns true if this biome has the given configured feature, which must be registered
 	 * in the {@link net.minecraft.util.registry.BuiltinRegistries}.
 	 *
-	 * <p>This method is intended for use with the Vanilla configured features found in {@link net.minecraft.world.gen.feature.ConfiguredFeatures}.
+	 * <p>This method is intended for use with the Vanilla configured features found in
+	 * classes such as {@link net.minecraft.world.gen.feature.OreConfiguredFeatures}.
 	 */
 	default boolean hasBuiltInFeature(ConfiguredFeature<?, ?> configuredFeature) {
 		RegistryKey<ConfiguredFeature<?, ?>> key = BuiltInRegistryKeys.get(configuredFeature);
@@ -52,14 +54,42 @@ public interface BiomeSelectionContext {
 	}
 
 	/**
-	 * Returns true if this biome contains a configured feature with the given key.
+	 * Returns true if this biome has the given placed feature, which must be registered
+	 * in the {@link net.minecraft.util.registry.BuiltinRegistries}.
+	 *
+	 * <p>This method is intended for use with the Vanilla placed features found in
+	 * classes such as {@link net.minecraft.world.gen.feature.OrePlacedFeatures}.
+	 */
+	default boolean hasBuiltInPlacedFeature(PlacedFeature placedFeature) {
+		return hasPlacedFeature(BuiltInRegistryKeys.get(placedFeature));
+	}
+
+	/**
+	 * Returns true if this biome contains a placed feature referencing a configured feature with the given key.
 	 */
 	default boolean hasFeature(RegistryKey<ConfiguredFeature<?, ?>> key) {
-		List<List<Supplier<ConfiguredFeature<?, ?>>>> featureSteps = getBiome().getGenerationSettings().getFeatures();
+		List<List<Supplier<PlacedFeature>>> featureSteps = getBiome().getGenerationSettings().getFeatures();
 
-		for (List<Supplier<ConfiguredFeature<?, ?>>> featureSuppliers : featureSteps) {
-			for (Supplier<ConfiguredFeature<?, ?>> featureSupplier : featureSuppliers) {
-				if (getFeatureKey(featureSupplier.get()).orElse(null) == key) {
+		for (List<Supplier<PlacedFeature>> featureSuppliers : featureSteps) {
+			for (Supplier<PlacedFeature> featureSupplier : featureSuppliers) {
+				if (featureSupplier.get().getDecoratedFeatures().anyMatch(cf -> getFeatureKey(cf).orElse(null) == key)) {
+					return true;
+				}
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Returns true if this biome contains a placed feature with the given key.
+	 */
+	default boolean hasPlacedFeature(RegistryKey<PlacedFeature> key) {
+		List<List<Supplier<PlacedFeature>>> featureSteps = getBiome().getGenerationSettings().getFeatures();
+
+		for (List<Supplier<PlacedFeature>> featureSuppliers : featureSteps) {
+			for (Supplier<PlacedFeature> featureSupplier : featureSuppliers) {
+				if (getPlacedFeatureKey(featureSupplier.get()).orElse(null) == key) {
 					return true;
 				}
 			}
@@ -75,6 +105,13 @@ public interface BiomeSelectionContext {
 	 */
 	Optional<RegistryKey<ConfiguredFeature<?, ?>>> getFeatureKey(ConfiguredFeature<?, ?> configuredFeature);
 
+	/**
+	 * Tries to retrieve the registry key for the given placed feature, which should be from this biomes
+	 * current feature list. May be empty if the placed feature is not registered, or does not come
+	 * from this biomes feature list.
+	 */
+	Optional<RegistryKey<PlacedFeature>> getPlacedFeatureKey(PlacedFeature placedFeature);
+
 	/**
 	 * Returns true if the given built-in configured structure from {@link net.minecraft.util.registry.BuiltinRegistries}
 	 * can start in this biome.

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/impl/biome/modification/BiomeModificationContextImpl.java

@@ -33,6 +33,7 @@ import com.google.common.collect.ImmutableMap;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
+import net.minecraft.world.gen.feature.PlacedFeature;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.SpawnGroup;
 import net.minecraft.sound.BiomeAdditionsSound;
@@ -56,30 +57,21 @@ import net.minecraft.world.gen.feature.Feature;
 import net.minecraft.world.gen.feature.StructureFeature;
 
 import net.fabricmc.fabric.api.biome.v1.BiomeModificationContext;
-import net.fabricmc.fabric.mixin.biome.modification.BiomeAccessor;
-import net.fabricmc.fabric.mixin.biome.modification.BiomeEffectsAccessor;
-import net.fabricmc.fabric.mixin.biome.modification.BiomeWeatherAccessor;
-import net.fabricmc.fabric.mixin.biome.modification.GenerationSettingsAccessor;
-import net.fabricmc.fabric.mixin.biome.modification.SpawnDensityAccessor;
-import net.fabricmc.fabric.mixin.biome.modification.SpawnSettingsAccessor;
 
 @ApiStatus.Internal
 public class BiomeModificationContextImpl implements BiomeModificationContext {
 	private final DynamicRegistryManager registries;
 	private final RegistryKey<Biome> biomeKey;
 	private final Biome biome;
-	private final BiomeAccessor biomeAccessor;
 	private final WeatherContext weather;
 	private final EffectsContext effects;
 	private final GenerationSettingsContextImpl generationSettings;
 	private final SpawnSettingsContextImpl spawnSettings;
 
-	@SuppressWarnings("ConstantConditions")
 	public BiomeModificationContextImpl(DynamicRegistryManager registries, RegistryKey<Biome> biomeKey, Biome biome) {
 		this.registries = registries;
 		this.biomeKey = biomeKey;
 		this.biome = biome;
-		this.biomeAccessor = (BiomeAccessor) (Object) biome;
 		this.weather = new WeatherContextImpl();
 		this.effects = new EffectsContextImpl();
 		this.generationSettings = new GenerationSettingsContextImpl();
@@ -88,7 +80,7 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 
 	@Override
 	public void setCategory(Biome.Category category) {
-		biomeAccessor.fabric_setCategory(category);
+		biome.category = category;
 	}
 
 	@Override
@@ -120,109 +112,98 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 	}
 
 	private class WeatherContextImpl implements WeatherContext {
-		private final BiomeWeatherAccessor accessor = (BiomeWeatherAccessor) biomeAccessor.fabric_getWeather();
+		private final Biome.Weather weather = biome.weather;
 
 		@Override
 		public void setPrecipitation(Biome.Precipitation precipitation) {
-			Objects.requireNonNull(precipitation);
-			accessor.setPrecipitation(precipitation);
+			weather.precipitation = Objects.requireNonNull(precipitation);
 		}
 
 		@Override
 		public void setTemperature(float temperature) {
-			accessor.setTemperature(temperature);
+			weather.temperature = temperature;
 		}
 
 		@Override
 		public void setTemperatureModifier(Biome.TemperatureModifier temperatureModifier) {
-			Objects.requireNonNull(temperatureModifier);
-			accessor.setTemperatureModifier(temperatureModifier);
+			weather.temperatureModifier = Objects.requireNonNull(temperatureModifier);
 		}
 
 		@Override
 		public void setDownfall(float downfall) {
-			accessor.setDownfall(downfall);
+			weather.downfall = downfall;
 		}
 	}
 
 	private class EffectsContextImpl implements EffectsContext {
-		private final BiomeEffectsAccessor accessor = (BiomeEffectsAccessor) biome.getEffects();
+		private final BiomeEffects effects = biome.getEffects();
 
 		@Override
 		public void setFogColor(int color) {
-			accessor.fabric_setFogColor(color);
+			effects.fogColor = color;
 		}
 
 		@Override
 		public void setWaterColor(int color) {
-			accessor.fabric_setWaterColor(color);
+			effects.waterColor = color;
 		}
 
 		@Override
 		public void setWaterFogColor(int color) {
-			accessor.fabric_setWaterFogColor(color);
+			effects.waterFogColor = color;
 		}
 
 		@Override
 		public void setSkyColor(int color) {
-			accessor.fabric_setSkyColor(color);
+			effects.skyColor = color;
 		}
 
 		@Override
 		public void setFoliageColor(Optional<Integer> color) {
-			Objects.requireNonNull(color);
-			accessor.fabric_setFoliageColor(color);
+			effects.foliageColor = Objects.requireNonNull(color);
 		}
 
 		@Override
 		public void setGrassColor(Optional<Integer> color) {
-			Objects.requireNonNull(color);
-			accessor.fabric_setGrassColor(color);
+			effects.grassColor = Objects.requireNonNull(color);
 		}
 
 		@Override
 		public void setGrassColorModifier(@NotNull BiomeEffects.GrassColorModifier colorModifier) {
-			Objects.requireNonNull(colorModifier);
-			accessor.fabric_setGrassColorModifier(colorModifier);
+			effects.grassColorModifier = Objects.requireNonNull(colorModifier);
 		}
 
 		@Override
 		public void setParticleConfig(Optional<BiomeParticleConfig> particleConfig) {
-			Objects.requireNonNull(particleConfig);
-			accessor.fabric_setParticleConfig(particleConfig);
+			effects.particleConfig = Objects.requireNonNull(particleConfig);
 		}
 
 		@Override
 		public void setAmbientSound(Optional<SoundEvent> sound) {
-			Objects.requireNonNull(sound);
-			accessor.fabric_setLoopSound(sound);
+			effects.loopSound = Objects.requireNonNull(sound);
 		}
 
 		@Override
 		public void setMoodSound(Optional<BiomeMoodSound> sound) {
-			Objects.requireNonNull(sound);
-			accessor.fabric_setMoodSound(sound);
+			effects.moodSound = Objects.requireNonNull(sound);
 		}
 
 		@Override
 		public void setAdditionsSound(Optional<BiomeAdditionsSound> sound) {
-			Objects.requireNonNull(sound);
-			accessor.fabric_setAdditionsSound(sound);
+			effects.additionsSound = Objects.requireNonNull(sound);
 		}
 
 		@Override
 		public void setMusic(Optional<MusicSound> sound) {
-			Objects.requireNonNull(sound);
-			accessor.fabric_setMusic(sound);
+			effects.music = Objects.requireNonNull(sound);
 		}
 	}
 
 	private class GenerationSettingsContextImpl implements GenerationSettingsContext {
 		private final Registry<ConfiguredCarver<?>> carvers = registries.get(Registry.CONFIGURED_CARVER_KEY);
-		private final Registry<ConfiguredFeature<?, ?>> features = registries.get(Registry.CONFIGURED_FEATURE_KEY);
+		private final Registry<PlacedFeature> features = registries.get(Registry.PLACED_FEATURE_KEY);
 		private final Registry<ConfiguredStructureFeature<?, ?>> structures = registries.get(Registry.CONFIGURED_STRUCTURE_FEATURE_KEY);
 		private final GenerationSettings generationSettings = biome.getGenerationSettings();
-		private final GenerationSettingsAccessor accessor = (GenerationSettingsAccessor) generationSettings;
 
 		/**
 		 * Unfreeze the immutable lists found in the generation settings, and make sure they're filled up to every
@@ -236,7 +217,7 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 
 		private void unfreezeCarvers() {
 			Map<GenerationStep.Carver, List<Supplier<ConfiguredCarver<?>>>> carversByStep = new EnumMap<>(GenerationStep.Carver.class);
-			carversByStep.putAll(accessor.fabric_getCarvers());
+			carversByStep.putAll(generationSettings.carvers);
 
 			for (GenerationStep.Carver step : GenerationStep.Carver.values()) {
 				List<Supplier<ConfiguredCarver<?>>> carvers = carversByStep.get(step);
@@ -250,23 +231,23 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 				carversByStep.put(step, carvers);
 			}
 
-			accessor.fabric_setCarvers(carversByStep);
+			generationSettings.carvers = carversByStep;
 		}
 
 		private void unfreezeFeatures() {
-			List<List<Supplier<ConfiguredFeature<?, ?>>>> features = accessor.fabric_getFeatures();
+			List<List<Supplier<PlacedFeature>>> features = generationSettings.features;
 			features = new ArrayList<>(features);
 
 			for (int i = 0; i < features.size(); i++) {
 				features.set(i, new ArrayList<>(features.get(i)));
 			}
 
-			accessor.fabric_setFeatures(features);
-			accessor.fabric_setAllowedFeatures(new HashSet<>(accessor.fabric_getAllowedFeatures()));
+			generationSettings.features = features;
+			generationSettings.allowedFeatures = new HashSet<>(generationSettings.allowedFeatures);
 		}
 
 		private void unfreezeFlowerFeatures() {
-			accessor.fabric_setFlowerFeatures(new ArrayList<>(accessor.fabric_getFlowerFeatures()));
+			generationSettings.flowerFeatures = new ArrayList<>(generationSettings.flowerFeatures);
 		}
 
 		/**
@@ -279,42 +260,42 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 		}
 
 		private void freezeCarvers() {
-			Map<GenerationStep.Carver, List<Supplier<ConfiguredCarver<?>>>> carversByStep = accessor.fabric_getCarvers();
+			Map<GenerationStep.Carver, List<Supplier<ConfiguredCarver<?>>>> carversByStep = generationSettings.carvers;
 
 			for (GenerationStep.Carver step : GenerationStep.Carver.values()) {
 				carversByStep.put(step, ImmutableList.copyOf(carversByStep.get(step)));
 			}
 
-			accessor.fabric_setCarvers(ImmutableMap.copyOf(carversByStep));
+			generationSettings.carvers = ImmutableMap.copyOf(carversByStep);
 		}
 
 		private void freezeFeatures() {
-			List<List<Supplier<ConfiguredFeature<?, ?>>>> featureSteps = accessor.fabric_getFeatures();
+			List<List<Supplier<PlacedFeature>>> featureSteps = generationSettings.features;
 
 			for (int i = 0; i < featureSteps.size(); i++) {
 				featureSteps.set(i, ImmutableList.copyOf(featureSteps.get(i)));
 			}
 
-			accessor.fabric_setFeatures(ImmutableList.copyOf(featureSteps));
-			accessor.fabric_setAllowedFeatures(Set.copyOf(accessor.fabric_getAllowedFeatures()));
+			generationSettings.features = ImmutableList.copyOf(featureSteps);
+			generationSettings.allowedFeatures = (Set.copyOf(generationSettings.allowedFeatures));
 		}
 
 		private void freezeFlowerFeatures() {
-			accessor.fabric_setFlowerFeatures(ImmutableList.copyOf(accessor.fabric_getFlowerFeatures()));
+			generationSettings.flowerFeatures = ImmutableList.copyOf(generationSettings.flowerFeatures);
 		}
 
 		@Override
-		public boolean removeFeature(GenerationStep.Feature step, RegistryKey<ConfiguredFeature<?, ?>> configuredFeatureKey) {
-			ConfiguredFeature<?, ?> configuredFeature = features.getOrThrow(configuredFeatureKey);
+		public boolean removeFeature(GenerationStep.Feature step, RegistryKey<PlacedFeature> placedFeatureKey) {
+			PlacedFeature configuredFeature = features.getOrThrow(placedFeatureKey);
 
 			int stepIndex = step.ordinal();
-			List<List<Supplier<ConfiguredFeature<?, ?>>>> featureSteps = accessor.fabric_getFeatures();
+			List<List<Supplier<PlacedFeature>>> featureSteps = generationSettings.features;
 
 			if (stepIndex >= featureSteps.size()) {
 				return false; // The step was not populated with any features yet
 			}
 
-			List<Supplier<ConfiguredFeature<?, ?>>> featuresInStep = featureSteps.get(stepIndex);
+			List<Supplier<PlacedFeature>> featuresInStep = featureSteps.get(stepIndex);
 
 			if (featuresInStep.removeIf(supplier -> supplier.get() == configuredFeature)) {
 				rebuildFlowerFeatures();
@@ -325,11 +306,11 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 		}
 
 		@Override
-		public void addFeature(GenerationStep.Feature step, RegistryKey<ConfiguredFeature<?, ?>> configuredFeatureKey) {
+		public void addFeature(GenerationStep.Feature step, RegistryKey<PlacedFeature> placedFeatureKey) {
 			// We do not need to delay evaluation of this since the registries are already fully built
-			ConfiguredFeature<?, ?> configuredFeature = features.getOrThrow(configuredFeatureKey);
+			PlacedFeature placedFeature = features.getOrThrow(placedFeatureKey);
 
-			List<List<Supplier<ConfiguredFeature<?, ?>>>> featureSteps = accessor.fabric_getFeatures();
+			List<List<Supplier<PlacedFeature>>> featureSteps = generationSettings.features;
 			int index = step.ordinal();
 
 			// Add new empty lists for the generation steps that have no features yet
@@ -337,8 +318,8 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 				featureSteps.add(new ArrayList<>());
 			}
 
-			featureSteps.get(index).add(() -> configuredFeature);
-			accessor.fabric_getAllowedFeatures().add(configuredFeature);
+			featureSteps.get(index).add(() -> placedFeature);
+			generationSettings.allowedFeatures.add(placedFeature);
 
 			// Ensure the list of flower features is up to date
 			rebuildFlowerFeatures();
@@ -348,13 +329,13 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 		public void addCarver(GenerationStep.Carver step, RegistryKey<ConfiguredCarver<?>> carverKey) {
 			// We do not need to delay evaluation of this since the registries are already fully built
 			ConfiguredCarver<?> carver = carvers.getOrThrow(carverKey);
-			accessor.fabric_getCarvers().get(step).add(() -> carver);
+			generationSettings.carvers.get(step).add(() -> carver);
 		}
 
 		@Override
 		public boolean removeCarver(GenerationStep.Carver step, RegistryKey<ConfiguredCarver<?>> configuredCarverKey) {
 			ConfiguredCarver<?> carver = carvers.getOrThrow(configuredCarverKey);
-			return accessor.fabric_getCarvers().get(step).removeIf(supplier -> supplier.get() == carver);
+			return generationSettings.carvers.get(step).removeIf(supplier -> supplier.get() == carver);
 		}
 
 		@Override
@@ -380,11 +361,11 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 		 * See the constructor of {@link GenerationSettings} for reference.
 		 */
 		private void rebuildFlowerFeatures() {
-			List<ConfiguredFeature<?, ?>> flowerFeatures = accessor.fabric_getFlowerFeatures();
+			List<ConfiguredFeature<?, ?>> flowerFeatures = generationSettings.flowerFeatures;
 			flowerFeatures.clear();
 
-			for (List<Supplier<ConfiguredFeature<?, ?>>> features : accessor.fabric_getFeatures()) {
-				for (Supplier<ConfiguredFeature<?, ?>> supplier : features) {
+			for (List<Supplier<PlacedFeature>> features : generationSettings.features) {
+				for (Supplier<PlacedFeature> supplier : features) {
 					supplier.get().getDecoratedFeatures()
 							.filter(configuredFeature -> configuredFeature.feature == Feature.FLOWER)
 							.forEachOrdered(flowerFeatures::add);
@@ -394,7 +375,7 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 	}
 
 	private class SpawnSettingsContextImpl implements SpawnSettingsContext {
-		private final SpawnSettingsAccessor accessor = (SpawnSettingsAccessor) biome.getSpawnSettings();
+		private final SpawnSettings spawnSettings = biome.getSpawnSettings();
 		private final EnumMap<SpawnGroup, List<SpawnSettings.SpawnEntry>> fabricSpawners = new EnumMap<>(SpawnGroup.class);
 
 		SpawnSettingsContextImpl() {
@@ -406,7 +387,7 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 			fabricSpawners.clear();
 
 			for (SpawnGroup spawnGroup : SpawnGroup.values()) {
-				Pool<SpawnSettings.SpawnEntry> entries = accessor.fabric_getSpawners().get(spawnGroup);
+				Pool<SpawnSettings.SpawnEntry> entries = spawnSettings.spawners.get(spawnGroup);
 
 				if (entries != null) {
 					fabricSpawners.put(spawnGroup, new ArrayList<>(entries.getEntries()));
@@ -417,7 +398,7 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 		}
 
 		private void unfreezeSpawnCost() {
-			accessor.fabric_setSpawnCosts(new HashMap<>(accessor.fabric_getSpawnCosts()));
+			spawnSettings.spawnCosts = new HashMap<>(spawnSettings.spawnCosts);
 		}
 
 		public void freeze() {
@@ -426,7 +407,7 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 		}
 
 		private void freezeSpawners() {
-			Map<SpawnGroup, Pool<SpawnSettings.SpawnEntry>> spawners = new HashMap<>(accessor.fabric_getSpawners());
+			Map<SpawnGroup, Pool<SpawnSettings.SpawnEntry>> spawners = new HashMap<>(spawnSettings.spawners);
 
 			for (Map.Entry<SpawnGroup, List<SpawnSettings.SpawnEntry>> entry : fabricSpawners.entrySet()) {
 				if (entry.getValue().isEmpty()) {
@@ -436,21 +417,21 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 				}
 			}
 
-			accessor.fabric_setSpawners(ImmutableMap.copyOf(spawners));
+			spawnSettings.spawners = ImmutableMap.copyOf(spawners);
 		}
 
 		private void freezeSpawnCosts() {
-			accessor.fabric_setSpawnCosts(ImmutableMap.copyOf(accessor.fabric_getSpawnCosts()));
+			spawnSettings.spawnCosts = ImmutableMap.copyOf(spawnSettings.spawnCosts);
 		}
 
 		@Override
 		public void setPlayerSpawnFriendly(boolean playerSpawnFriendly) {
-			accessor.fabric_setPlayerSpawnFriendly(playerSpawnFriendly);
+			spawnSettings.playerSpawnFriendly = playerSpawnFriendly;
 		}
 
 		@Override
 		public void setCreatureSpawnProbability(float probability) {
-			accessor.fabric_setCreatureSpawnProbability(probability);
+			spawnSettings.creatureSpawnProbability = probability;
 		}
 
 		@Override
@@ -477,12 +458,12 @@ public class BiomeModificationContextImpl implements BiomeModificationContext {
 		@Override
 		public void setSpawnCost(EntityType<?> entityType, double mass, double gravityLimit) {
 			Objects.requireNonNull(entityType);
-			accessor.fabric_getSpawnCosts().put(entityType, SpawnDensityAccessor.create(gravityLimit, mass));
+			spawnSettings.spawnCosts.put(entityType, new SpawnSettings.SpawnDensity(gravityLimit, mass));
 		}
 
 		@Override
 		public void clearSpawnCost(EntityType<?> entityType) {
-			accessor.fabric_getSpawnCosts().remove(entityType);
+			spawnSettings.spawnCosts.remove(entityType);
 		}
 	}
 }

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/impl/biome/modification/BiomeSelectionContextImpl.java

@@ -21,6 +21,7 @@ import java.util.Optional;
 
 import org.jetbrains.annotations.ApiStatus;
 
+import net.minecraft.world.gen.feature.PlacedFeature;
 import net.minecraft.util.registry.DynamicRegistryManager;
 import net.minecraft.util.registry.Registry;
 import net.minecraft.util.registry.RegistryKey;
@@ -60,6 +61,12 @@ public class BiomeSelectionContextImpl implements BiomeSelectionContext {
 		return registry.getKey(configuredFeature);
 	}
 
+	@Override
+	public Optional<RegistryKey<PlacedFeature>> getPlacedFeatureKey(PlacedFeature placedFeature) {
+		Registry<PlacedFeature> registry = dynamicRegistries.get(Registry.PLACED_FEATURE_KEY);
+		return registry.getKey(placedFeature);
+	}
+
 	@Override
 	public boolean hasStructure(RegistryKey<ConfiguredStructureFeature<?, ?>> key) {
 		ConfiguredStructureFeature<?, ?> instance = dynamicRegistries.get(Registry.CONFIGURED_STRUCTURE_FEATURE_KEY).get(key);

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/impl/biome/modification/BuiltInRegistryKeys.java

@@ -18,6 +18,7 @@ package net.fabricmc.fabric.impl.biome.modification;
 
 import org.jetbrains.annotations.ApiStatus;
 
+import net.minecraft.world.gen.feature.PlacedFeature;
 import net.minecraft.util.registry.BuiltinRegistries;
 import net.minecraft.util.registry.RegistryKey;
 import net.minecraft.world.gen.carver.ConfiguredCarver;
@@ -43,6 +44,11 @@ public final class BuiltInRegistryKeys {
 				.orElseThrow(() -> new IllegalArgumentException("Given configured feature is not built-in: " + configuredFeature));
 	}
 
+	public static RegistryKey<PlacedFeature> get(PlacedFeature placedFeature) {
+		return BuiltinRegistries.PLACED_FEATURE.getKey(placedFeature)
+				.orElseThrow(() -> new IllegalArgumentException("Given placed feature is not built-in: " + placedFeature));
+	}
+
 	public static RegistryKey<ConfiguredCarver<?>> get(ConfiguredCarver<?> configuredCarver) {
 		return BuiltinRegistries.CONFIGURED_CARVER.getKey(configuredCarver)
 				.orElseThrow(() -> new IllegalArgumentException("Given configured carver is not built-in: " + configuredCarver));

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/mixin/biome/MixinMultiNoiseBiomeSource.java

@@ -23,8 +23,8 @@ import java.util.function.Supplier;
 import com.mojang.datafixers.util.Pair;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.ModifyArgs;
-import org.spongepowered.asm.mixin.injection.invoke.arg.Args;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
 import net.minecraft.util.registry.Registry;
 import net.minecraft.world.biome.Biome;
@@ -39,9 +39,9 @@ import net.fabricmc.fabric.impl.biome.NetherBiomeData;
 @Mixin(MultiNoiseBiomeSource.Preset.class)
 public class MixinMultiNoiseBiomeSource {
 	// NOTE: This is a lambda-function in the NETHER preset field initializer
-	@ModifyArgs(method = "method_31088", at = @At(value = "INVOKE", target = "Lnet/minecraft/world/biome/source/MultiNoiseBiomeSource;<init>(Lnet/minecraft/world/biome/source/util/MultiNoiseUtil$Entries;Ljava/util/Optional;)V"))
-	private static void appendNetherBiomes(Args args, MultiNoiseBiomeSource.Preset preset, Registry<Biome> registry) {
-		MultiNoiseUtil.Entries<Biome> biomes = args.get(0);
+	@Inject(method = "method_31088", at = @At("RETURN"), cancellable = true)
+	private static void appendNetherBiomes(Registry<Biome> registry, CallbackInfoReturnable<MultiNoiseUtil.Entries<Supplier<Biome>>> cri) {
+		MultiNoiseUtil.Entries<Supplier<Biome>> biomes = cri.getReturnValue();
 		List<Pair<MultiNoiseUtil.NoiseHypercube, Supplier<Biome>>> entries = new ArrayList<>(biomes.getEntries());
 
 		// add fabric biome noise point data to list && BiomeSource biome list
@@ -51,6 +51,6 @@ public class MixinMultiNoiseBiomeSource {
 			entries.add(Pair.of(noisePoint, () -> biome));
 		});
 
-		args.set(0, new MultiNoiseUtil.Entries<>(entries));
+		cri.setReturnValue(new MultiNoiseUtil.Entries<>(entries));
 	}
 }

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/mixin/biome/modification/BiomeAccessor.java

@@ -1,42 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.fabricmc.fabric.mixin.biome.modification;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Mutable;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-import net.minecraft.world.biome.Biome;
-import net.minecraft.world.biome.GenerationSettings;
-import net.minecraft.world.biome.SpawnSettings;
-
-@Mixin(Biome.class)
-public interface BiomeAccessor {
-	@Accessor("weather")
-	Biome.Weather fabric_getWeather();
-
-	@Accessor("generationSettings")
-	GenerationSettings fabric_getGenerationSettings();
-
-	@Accessor("spawnSettings")
-	@Mutable
-	SpawnSettings fabric_getSpawnSettings();
-
-	@Accessor("category")
-	@Mutable
-	void fabric_setCategory(Biome.Category category);
-}

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/mixin/biome/modification/BiomeEffectsAccessor.java

@@ -1,81 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.fabricmc.fabric.mixin.biome.modification;
-
-import java.util.Optional;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Mutable;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-import net.minecraft.sound.BiomeAdditionsSound;
-import net.minecraft.sound.BiomeMoodSound;
-import net.minecraft.sound.MusicSound;
-import net.minecraft.sound.SoundEvent;
-import net.minecraft.world.biome.BiomeEffects;
-import net.minecraft.world.biome.BiomeParticleConfig;
-
-@Mixin(BiomeEffects.class)
-public interface BiomeEffectsAccessor {
-	@Accessor("fogColor")
-	@Mutable
-	void fabric_setFogColor(int value);
-
-	@Accessor("waterColor")
-	@Mutable
-	void fabric_setWaterColor(int value);
-
-	@Accessor("waterFogColor")
-	@Mutable
-	void fabric_setWaterFogColor(int value);
-
-	@Accessor("skyColor")
-	@Mutable
-	void fabric_setSkyColor(int value);
-
-	@Accessor("foliageColor")
-	@Mutable
-	void fabric_setFoliageColor(Optional<Integer> value);
-
-	@Accessor("grassColor")
-	@Mutable
-	void fabric_setGrassColor(Optional<Integer> value);
-
-	@Accessor("grassColorModifier")
-	@Mutable
-	void fabric_setGrassColorModifier(BiomeEffects.GrassColorModifier value);
-
-	@Accessor("particleConfig")
-	@Mutable
-	void fabric_setParticleConfig(Optional<BiomeParticleConfig> value);
-
-	@Accessor("loopSound")
-	@Mutable
-	void fabric_setLoopSound(Optional<SoundEvent> value);
-
-	@Accessor("moodSound")
-	@Mutable
-	void fabric_setMoodSound(Optional<BiomeMoodSound> value);
-
-	@Accessor("additionsSound")
-	@Mutable
-	void fabric_setAdditionsSound(Optional<BiomeAdditionsSound> value);
-
-	@Accessor("music")
-	@Mutable
-	void fabric_setMusic(Optional<MusicSound> value);
-}

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/mixin/biome/modification/BiomeWeatherAccessor.java

@@ -1,54 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.fabricmc.fabric.mixin.biome.modification;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Mutable;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-import net.minecraft.world.biome.Biome;
-
-@Mixin(Biome.Weather.class)
-public interface BiomeWeatherAccessor {
-	@Accessor
-	Biome.Precipitation getPrecipitation();
-
-	@Accessor
-	@Mutable
-	void setPrecipitation(Biome.Precipitation precipitation);
-
-	@Accessor
-	float getTemperature();
-
-	@Accessor
-	@Mutable
-	void setTemperature(float temperature);
-
-	@Accessor
-	Biome.TemperatureModifier getTemperatureModifier();
-
-	@Accessor
-	@Mutable
-	void setTemperatureModifier(Biome.TemperatureModifier temperatureModifier);
-
-	@Accessor
-	float getDownfall();
-
-	@Accessor
-	@Mutable
-	void setDownfall(float downfall);
-}

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/mixin/biome/modification/GenerationSettingsAccessor.java

@@ -1,62 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.fabricmc.fabric.mixin.biome.modification;
-
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.function.Supplier;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Mutable;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-import net.minecraft.world.biome.GenerationSettings;
-import net.minecraft.world.gen.GenerationStep;
-import net.minecraft.world.gen.carver.ConfiguredCarver;
-import net.minecraft.world.gen.feature.ConfiguredFeature;
-
-@Mixin(GenerationSettings.class)
-public interface GenerationSettingsAccessor {
-	@Accessor("carvers")
-	Map<GenerationStep.Carver, List<Supplier<ConfiguredCarver<?>>>> fabric_getCarvers();
-
-	@Accessor("features")
-	List<List<Supplier<ConfiguredFeature<?, ?>>>> fabric_getFeatures();
-
-	@Accessor("allowedFeatures")
-	Set<ConfiguredFeature<?, ?>> fabric_getAllowedFeatures();
-
-	@Accessor("flowerFeatures")
-	List<ConfiguredFeature<?, ?>> fabric_getFlowerFeatures();
-
-	@Accessor("carvers")
-	@Mutable
-	void fabric_setCarvers(Map<GenerationStep.Carver, List<Supplier<ConfiguredCarver<?>>>> value);
-
-	@Accessor("features")
-	@Mutable
-	void fabric_setFeatures(List<List<Supplier<ConfiguredFeature<?, ?>>>> value);
-
-	@Accessor("allowedFeatures")
-	@Mutable
-	void fabric_setAllowedFeatures(Set<ConfiguredFeature<?, ?>> allowedFeatures);
-
-	@Accessor("flowerFeatures")
-	@Mutable
-	void fabric_setFlowerFeatures(List<ConfiguredFeature<?, ?>> value);
-}

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/mixin/biome/modification/SpawnDensityAccessor.java

@@ -1,30 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.fabricmc.fabric.mixin.biome.modification;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.gen.Invoker;
-
-import net.minecraft.world.biome.SpawnSettings;
-
-@Mixin(SpawnSettings.SpawnDensity.class)
-public interface SpawnDensityAccessor {
-	@Invoker("<init>")
-	static SpawnSettings.SpawnDensity create(double gravityLimit, double mass) {
-		throw new AssertionError("mixin");
-	}
-}

fabric-biome-api-v1/src/main/java/net/fabricmc/fabric/mixin/biome/modification/SpawnSettingsAccessor.java

@@ -1,53 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.fabricmc.fabric.mixin.biome.modification;
-
-import java.util.Map;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.Mutable;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-import net.minecraft.util.collection.Pool;
-import net.minecraft.entity.EntityType;
-import net.minecraft.entity.SpawnGroup;
-import net.minecraft.world.biome.SpawnSettings;
-
-@Mixin(SpawnSettings.class)
-public interface SpawnSettingsAccessor {
-	@Accessor("creatureSpawnProbability")
-	@Mutable
-	void fabric_setCreatureSpawnProbability(float probability);
-
-	@Accessor("spawners")
-	Map<SpawnGroup, Pool<SpawnSettings.SpawnEntry>> fabric_getSpawners();
-
-	@Accessor("spawners")
-	@Mutable
-	void fabric_setSpawners(Map<SpawnGroup, Pool<SpawnSettings.SpawnEntry>> spawners);
-
-	@Accessor("spawnCosts")
-	Map<EntityType<?>, SpawnSettings.SpawnDensity> fabric_getSpawnCosts();
-
-	@Accessor("spawnCosts")
-	@Mutable
-	void fabric_setSpawnCosts(Map<EntityType<?>, SpawnSettings.SpawnDensity> spawnCosts);
-
-	@Accessor("playerSpawnFriendly")
-	@Mutable
-	void fabric_setPlayerSpawnFriendly(boolean playerSpawnFriendly);
-}

fabric-biome-api-v1/src/main/resources/fabric-biome-api-v1.accesswidener

@@ -2,3 +2,68 @@ accessWidener	v1	named
 accessible  class   net/minecraft/world/biome/Biome$Weather
 accessible field net/minecraft/world/gen/chunk/StructuresConfig configuredStructures Lcom/google/common/collect/ImmutableMap;
 mutable field net/minecraft/world/gen/chunk/StructuresConfig configuredStructures Lcom/google/common/collect/ImmutableMap;
+
+# Top-Level Biome Fields Access
+accessible field net/minecraft/world/biome/Biome weather Lnet/minecraft/world/biome/Biome$Weather;
+accessible field net/minecraft/world/biome/Biome generationSettings Lnet/minecraft/world/biome/GenerationSettings;
+accessible field net/minecraft/world/biome/Biome spawnSettings Lnet/minecraft/world/biome/SpawnSettings;
+accessible field net/minecraft/world/biome/Biome category Lnet/minecraft/world/biome/Biome$Category;
+mutable field net/minecraft/world/biome/Biome category Lnet/minecraft/world/biome/Biome$Category;
+
+# Biome Weather
+accessible field net/minecraft/world/biome/Biome$Weather precipitation Lnet/minecraft/world/biome/Biome$Precipitation;
+mutable field net/minecraft/world/biome/Biome$Weather precipitation Lnet/minecraft/world/biome/Biome$Precipitation;
+accessible field net/minecraft/world/biome/Biome$Weather temperature F
+mutable field net/minecraft/world/biome/Biome$Weather temperature F
+accessible field net/minecraft/world/biome/Biome$Weather temperatureModifier Lnet/minecraft/world/biome/Biome$TemperatureModifier;
+mutable field net/minecraft/world/biome/Biome$Weather temperatureModifier Lnet/minecraft/world/biome/Biome$TemperatureModifier;
+accessible field net/minecraft/world/biome/Biome$Weather downfall F
+mutable field net/minecraft/world/biome/Biome$Weather downfall F
+
+# Biome Effects
+accessible field net/minecraft/world/biome/BiomeEffects fogColor I
+mutable field net/minecraft/world/biome/BiomeEffects fogColor I
+accessible field net/minecraft/world/biome/BiomeEffects waterColor I
+mutable field net/minecraft/world/biome/BiomeEffects waterColor I
+accessible field net/minecraft/world/biome/BiomeEffects waterFogColor I
+mutable field net/minecraft/world/biome/BiomeEffects waterFogColor I
+accessible field net/minecraft/world/biome/BiomeEffects skyColor I
+mutable field net/minecraft/world/biome/BiomeEffects skyColor I
+accessible field net/minecraft/world/biome/BiomeEffects foliageColor Ljava/util/Optional;
+mutable field net/minecraft/world/biome/BiomeEffects foliageColor Ljava/util/Optional;
+accessible field net/minecraft/world/biome/BiomeEffects grassColor Ljava/util/Optional;
+mutable field net/minecraft/world/biome/BiomeEffects grassColor Ljava/util/Optional;
+accessible field net/minecraft/world/biome/BiomeEffects grassColorModifier Lnet/minecraft/world/biome/BiomeEffects$GrassColorModifier;
+mutable field net/minecraft/world/biome/BiomeEffects grassColorModifier Lnet/minecraft/world/biome/BiomeEffects$GrassColorModifier;
+accessible field net/minecraft/world/biome/BiomeEffects particleConfig Ljava/util/Optional;
+mutable field net/minecraft/world/biome/BiomeEffects particleConfig Ljava/util/Optional;
+accessible field net/minecraft/world/biome/BiomeEffects loopSound Ljava/util/Optional;
+mutable field net/minecraft/world/biome/BiomeEffects loopSound Ljava/util/Optional;
+accessible field net/minecraft/world/biome/BiomeEffects moodSound Ljava/util/Optional;
+mutable field net/minecraft/world/biome/BiomeEffects moodSound Ljava/util/Optional;
+accessible field net/minecraft/world/biome/BiomeEffects additionsSound Ljava/util/Optional;
+mutable field net/minecraft/world/biome/BiomeEffects additionsSound Ljava/util/Optional;
+accessible field net/minecraft/world/biome/BiomeEffects music Ljava/util/Optional;
+mutable field net/minecraft/world/biome/BiomeEffects music Ljava/util/Optional;
+
+# Spawn Settings / Density
+accessible field net/minecraft/world/biome/SpawnSettings creatureSpawnProbability F
+mutable field net/minecraft/world/biome/SpawnSettings creatureSpawnProbability F
+accessible field net/minecraft/world/biome/SpawnSettings spawners Ljava/util/Map;
+mutable field net/minecraft/world/biome/SpawnSettings spawners Ljava/util/Map;
+accessible field net/minecraft/world/biome/SpawnSettings spawnCosts Ljava/util/Map;
+mutable field net/minecraft/world/biome/SpawnSettings spawnCosts Ljava/util/Map;
+accessible field net/minecraft/world/biome/SpawnSettings playerSpawnFriendly Z
+mutable field net/minecraft/world/biome/SpawnSettings playerSpawnFriendly Z
+
+accessible method net/minecraft/world/biome/SpawnSettings$SpawnDensity <init> (DD)V
+
+# Generation Settings
+accessible field net/minecraft/world/biome/GenerationSettings carvers Ljava/util/Map;
+mutable field net/minecraft/world/biome/GenerationSettings carvers Ljava/util/Map;
+accessible field net/minecraft/world/biome/GenerationSettings features Ljava/util/List;
+mutable field net/minecraft/world/biome/GenerationSettings features Ljava/util/List;
+accessible field net/minecraft/world/biome/GenerationSettings flowerFeatures Ljava/util/List;
+mutable field net/minecraft/world/biome/GenerationSettings flowerFeatures Ljava/util/List;
+accessible field net/minecraft/world/biome/GenerationSettings allowedFeatures Ljava/util/Set;
+mutable field net/minecraft/world/biome/GenerationSettings allowedFeatures Ljava/util/Set;

fabric-biome-api-v1/src/main/resources/fabric-biome-api-v1.mixins.json

@@ -3,15 +3,8 @@
   "package": "net.fabricmc.fabric.mixin.biome",
   "compatibilityLevel": "JAVA_17",
   "mixins": [
-    "modification.BiomeAccessor",
-    "modification.BiomeEffectsAccessor",
-    "modification.BiomeWeatherAccessor",
-    "modification.BiomeWeatherAccessor",
     "modification.DynamicRegistryManagerImplMixin",
-    "modification.GenerationSettingsAccessor",
     "modification.RegistryOpsMixin",
-    "modification.SpawnDensityAccessor",
-    "modification.SpawnSettingsAccessor",
     "MixinMultiNoiseBiomeSource",
     "MixinTheEndBiomeSource"
   ],

fabric-biome-api-v1/src/testmod/java/net/fabricmc/fabric/test/biome/FabricBiomeTest.java

@@ -24,17 +24,21 @@ import net.minecraft.util.registry.RegistryKey;
 import net.minecraft.world.biome.Biome;
 import net.minecraft.world.biome.BiomeEffects;
 import net.minecraft.world.biome.BiomeKeys;
-import net.minecraft.world.biome.OverworldBiomeCreator;
 import net.minecraft.world.biome.GenerationSettings;
+import net.minecraft.world.biome.OverworldBiomeCreator;
 import net.minecraft.world.biome.SpawnSettings;
 import net.minecraft.world.biome.TheNetherBiomeCreator;
 import net.minecraft.world.biome.source.util.MultiNoiseUtil;
 import net.minecraft.world.gen.GenerationStep;
+import net.minecraft.world.gen.decorator.BiomePlacementModifier;
+import net.minecraft.world.gen.decorator.SquarePlacementModifier;
 import net.minecraft.world.gen.feature.ConfiguredFeature;
-import net.minecraft.world.gen.feature.ConfiguredFeatures;
 import net.minecraft.world.gen.feature.DefaultBiomeFeatures;
+import net.minecraft.world.gen.feature.EndPlacedFeatures;
 import net.minecraft.world.gen.feature.Feature;
 import net.minecraft.world.gen.feature.FeatureConfig;
+import net.minecraft.world.gen.feature.PlacedFeature;
+import net.minecraft.world.gen.feature.PlacedFeatures;
 
 import net.fabricmc.api.ModInitializer;
 import net.fabricmc.fabric.api.biome.v1.BiomeModifications;
@@ -43,7 +47,6 @@ import net.fabricmc.fabric.api.biome.v1.ModificationPhase;
 import net.fabricmc.fabric.api.biome.v1.NetherBiomes;
 import net.fabricmc.fabric.api.biome.v1.TheEndBiomes;
 import net.fabricmc.fabric.api.tag.TagFactory;
-import net.fabricmc.fabric.test.biome.mixin.DecoratorsAccessor;
 
 /**
  * <b>NOTES FOR TESTING:</b>
@@ -68,8 +71,8 @@ public class FabricBiomeTest implements ModInitializer {
 	public void onInitialize() {
 		Registry.register(BuiltinRegistries.BIOME, TEST_CRIMSON_FOREST.getValue(), TheNetherBiomeCreator.createCrimsonForest());
 
-		NetherBiomes.addNetherBiome(BiomeKeys.THE_END, MultiNoiseUtil.createNoiseValuePoint(0.0F, 0.5F, 0.0F, 0.0F, 0.0f, 0.1F));
-		NetherBiomes.addNetherBiome(TEST_CRIMSON_FOREST, MultiNoiseUtil.createNoiseValuePoint(0.0F, 0.5F, 0.0F, 0.0F, 0.0f, 0.275F));
+		NetherBiomes.addNetherBiome(BiomeKeys.PLAINS, MultiNoiseUtil.createNoiseHypercube(0.0F, 0.5F, 0.0F, 0.0F, 0.0f, 0, 0.1F));
+		NetherBiomes.addNetherBiome(TEST_CRIMSON_FOREST, MultiNoiseUtil.createNoiseHypercube(0.0F, 0.0F, 0.0f, 0.35F, 0.0f, 0.35F, 0.2F));
 
 		Registry.register(BuiltinRegistries.BIOME, CUSTOM_PLAINS.getValue(), OverworldBiomeCreator.createPlains(false, false, false));
 
@@ -91,8 +94,12 @@ public class FabricBiomeTest implements ModInitializer {
 		TheEndBiomes.addMidlandsBiome(TEST_END_HIGHLANDS, TEST_END_MIDLANDS, 1.0);
 		TheEndBiomes.addBarrensBiome(TEST_END_HIGHLANDS, TEST_END_BARRRENS, 1.0);
 
-		ConfiguredFeature<?, ?> COMMON_DESERT_WELL = Feature.DESERT_WELL.configure(FeatureConfig.DEFAULT).decorate(DecoratorsAccessor.getSQUARE_HEIGHTMAP());
-		Registry.register(BuiltinRegistries.CONFIGURED_FEATURE, new Identifier(MOD_ID, "common_desert_well"), COMMON_DESERT_WELL);
+		ConfiguredFeature<?, ?> COMMON_DESERT_WELL = Feature.DESERT_WELL.configure(FeatureConfig.DEFAULT);
+		Registry.register(BuiltinRegistries.CONFIGURED_FEATURE, new Identifier(MOD_ID, "fab_desert_well"), COMMON_DESERT_WELL);
+
+		// The placement config is taken from the vanilla desert well, but no randomness
+		PlacedFeature PLACED_COMMON_DESERT_WELL = COMMON_DESERT_WELL.withPlacement(SquarePlacementModifier.of(), PlacedFeatures.MOTION_BLOCKING_HEIGHTMAP, BiomePlacementModifier.of());
+		Registry.register(BuiltinRegistries.PLACED_FEATURE, new Identifier(MOD_ID, "fab_desert_well"), PLACED_COMMON_DESERT_WELL);
 
 		BiomeModifications.create(new Identifier("fabric:test_mod"))
 				.add(ModificationPhase.ADDITIONS,
@@ -102,7 +109,7 @@ public class FabricBiomeTest implements ModInitializer {
 						BiomeSelectors.categories(Biome.Category.DESERT),
 						context -> {
 							context.getGenerationSettings().addFeature(GenerationStep.Feature.TOP_LAYER_MODIFICATION,
-									BuiltinRegistries.CONFIGURED_FEATURE.getKey(COMMON_DESERT_WELL).get()
+									BuiltinRegistries.PLACED_FEATURE.getKey(PLACED_COMMON_DESERT_WELL).get()
 							);
 						})
 				.add(ModificationPhase.ADDITIONS,
@@ -112,9 +119,9 @@ public class FabricBiomeTest implements ModInitializer {
 
 	// These are used for testing the spacing of custom end biomes.
 	private static Biome createEndHighlands() {
-		GenerationSettings.Builder builder = (new GenerationSettings.Builder())
-				.feature(GenerationStep.Feature.SURFACE_STRUCTURES, ConfiguredFeatures.END_GATEWAY)
-				.feature(GenerationStep.Feature.VEGETAL_DECORATION, ConfiguredFeatures.CHORUS_PLANT);
+		GenerationSettings.Builder builder = new GenerationSettings.Builder()
+				.feature(GenerationStep.Feature.SURFACE_STRUCTURES, EndPlacedFeatures.END_GATEWAY_RETURN)
+				.feature(GenerationStep.Feature.VEGETAL_DECORATION, EndPlacedFeatures.CHORUS_PLANT);
 		return composeEndSpawnSettings(builder);
 	}
 

fabric-biome-api-v1/src/testmod/java/net/fabricmc/fabric/test/biome/mixin/DecoratorsAccessor.java

@@ -1,30 +0,0 @@
-/*
- * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.fabricmc.fabric.test.biome.mixin;
-
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.gen.Accessor;
-
-import net.minecraft.world.gen.decorator.ConfiguredDecorator;
-
-@Mixin(targets = "net.minecraft.world.gen.feature.ConfiguredFeatures$Decorators")
-public interface DecoratorsAccessor {
-	@Accessor
-	static ConfiguredDecorator<?> getSQUARE_HEIGHTMAP() {
-		throw new UnsupportedOperationException("");
-	}
-}

fabric-biome-api-v1/src/testmod/resources/fabric-biome-testmod-api-v1.mixins.json

@@ -1,11 +0,0 @@
-{
-  "required": true,
-  "package": "net.fabricmc.fabric.test.biome.mixin",
-  "compatibilityLevel": "JAVA_17",
-  "mixins": [
-    "DecoratorsAccessor"
-  ],
-  "injectors": {
-    "defaultRequire": 1
-  }
-}

fabric-biome-api-v1/src/testmod/resources/fabric.mod.json

@@ -12,8 +12,5 @@
     "main": [
       "net.fabricmc.fabric.test.biome.FabricBiomeTest"
     ]
-  },
-  "mixins": [
-    "fabric-biome-testmod-api-v1.mixins.json"
-  ]
+  }
 }

settings.gradle

@@ -14,7 +14,7 @@ rootProject.name = "fabric-api"
 include 'fabric-api-base'
 
 include 'fabric-api-lookup-api-v1'
-//include 'fabric-biome-api-v1'
+include 'fabric-biome-api-v1'
 include 'fabric-blockrenderlayer-v1'
 include 'fabric-commands-v0'
 include 'fabric-command-api-v1'