Possible fix for missing SurfaceRules in Datapack worlds

src/main/java/ru/bclib/api/biomes/BiomeAPI.java

@@ -40,6 +40,7 @@ import net.minecraft.world.level.levelgen.GenerationStep.Decoration;
 import net.minecraft.world.level.levelgen.NoiseBasedChunkGenerator;
 import net.minecraft.world.level.levelgen.NoiseGeneratorSettings;
 import net.minecraft.world.level.levelgen.SurfaceRules;
+import net.minecraft.world.level.levelgen.SurfaceRules.RuleSource;
 import net.minecraft.world.level.levelgen.carver.ConfiguredWorldCarver;
 import net.minecraft.world.level.levelgen.feature.ConfiguredFeature;
 import net.minecraft.world.level.levelgen.feature.ConfiguredStructureFeature;
@@ -483,15 +484,9 @@ public class BiomeAPI {
 		}
 		
 		if (generator != null) {
-			List<SurfaceRules.RuleSource> rules = getRuleSources(biomes, level.dimension());
+			List<SurfaceRules.RuleSource> rules = getRuleSources(biomes);
 			SurfaceRuleProvider provider = SurfaceRuleProvider.class.cast(generator);
-			if (rules.size() > 0) {
+			changeSurfaceRules(rules, provider);
-				rules.add(provider.getSurfaceRule());
-				provider.setSurfaceRule(SurfaceRules.sequence(rules.toArray(new SurfaceRules.RuleSource[rules.size()])));
-			}
-			else {
-				provider.setSurfaceRule(null);
-			}
 		}
 		
 		List<BiConsumer<ResourceLocation, Biome>> modifications = MODIFICATIONS.get(level.dimension());
@@ -532,8 +527,14 @@ public class BiomeAPI {
 		accessor.bclib_setFeatures(featureList);
 	}
 	
-	private static List<SurfaceRules.RuleSource> getRuleSources(Set<Biome> biomes, ResourceKey<Level> dimensionType) {
+	private static List<SurfaceRules.RuleSource> getRuleSources(Set<Biome> biomes) {
-		Set<ResourceLocation> biomeIDs = biomes.stream().map(biome -> getBiomeID(biome)).collect(Collectors.toSet());
+		Set<ResourceLocation> biomeIDs = biomes.stream()
+											   .map(biome -> getBiomeID(biome))
+											   .collect(Collectors.toSet());
+		return getRuleSourcesFromIDs(biomeIDs);
+	}
+	
+	private static List<SurfaceRules.RuleSource> getRuleSourcesFromIDs(Set<ResourceLocation> biomeIDs) {
 		List<SurfaceRules.RuleSource> rules = Lists.newArrayList();
 		SURFACE_RULES.forEach((biomeID, rule) -> {
 			if (biomeIDs.contains(biomeID)) {
@@ -792,13 +793,31 @@ public class BiomeAPI {
 					.event(v.get())
 					.register((rawId, id, object) -> {
 						//BCLib.LOGGER.info(" #### " + rawId + ", " + object + ", " + id);
+						
+						//add back modded structures
 						StructureSettingsAccessor a = (StructureSettingsAccessor)object.structureSettings();
 						structureStarts.forEach(modifier -> changeStructureStarts(a, modifier));
+						
+						//add surface rules
+						if (biomeRegistry!=null) {
+							List<SurfaceRules.RuleSource> rules = getRuleSourcesFromIDs(biomeRegistry.keySet());
+							SurfaceRuleProvider provider = SurfaceRuleProvider.class.cast(object);
+							changeSurfaceRules(rules, provider);
+						}
 					});
 			}
 		});
 	}
 	
+	private static void changeSurfaceRules(List<RuleSource> rules, SurfaceRuleProvider provider) {
+		if (rules.size() > 0) {
+			provider.addCustomRules(rules);
+		}
+		else {
+			provider.clearCustomRules();
+		}
+	}
+	
 	public static void clearStructureStarts(){
 		structureStarts.clear();
 	}

src/main/java/ru/bclib/interfaces/SurfaceRuleProvider.java

@@ -1,9 +1,10 @@
 package ru.bclib.interfaces;
 
-import net.minecraft.world.level.levelgen.SurfaceRules;
+import net.minecraft.world.level.levelgen.SurfaceRules.RuleSource;
+
+import java.util.List;
 
 public interface SurfaceRuleProvider {
-	void setSurfaceRule(SurfaceRules.RuleSource surfaceRule);
+	void clearCustomRules();
-	
+	void addCustomRules(List<RuleSource> rules);
-	SurfaceRules.RuleSource getSurfaceRule();
 }

src/main/java/ru/bclib/mixin/common/NoiseGeneratorSettingsMixin.java

@@ -3,36 +3,65 @@ package ru.bclib.mixin.common;
 import net.minecraft.world.level.levelgen.NoiseGeneratorSettings;
 import net.minecraft.world.level.levelgen.SurfaceRules;
 import net.minecraft.world.level.levelgen.SurfaceRules.RuleSource;
+import org.apache.commons.codec.language.bm.Rule;
 import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
 import org.spongepowered.asm.mixin.Shadow;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 import ru.bclib.interfaces.SurfaceRuleProvider;
 
+import java.util.List;
+import java.util.stream.Collectors;
+
 @Mixin(NoiseGeneratorSettings.class)
 public class NoiseGeneratorSettingsMixin implements SurfaceRuleProvider {
+	@Mutable
 	@Final
 	@Shadow
 	private SurfaceRules.RuleSource surfaceRule;
 	
-	private SurfaceRules.RuleSource bclib_surfaceRule;
+	private SurfaceRules.RuleSource bclib_originalSurfaceRule;
 	
 	@Override
-	public void setSurfaceRule(SurfaceRules.RuleSource surfaceRule) {
+	public void clearCustomRules() {
-		bclib_surfaceRule = surfaceRule;
+		if (bclib_originalSurfaceRule != null){
-	}
+			this.surfaceRule = bclib_originalSurfaceRule;
-	
+			bclib_originalSurfaceRule = null;
-	@Override
-	public RuleSource getSurfaceRule() {
-		return surfaceRule;
-	}
-	
-	@Inject(method = "surfaceRule", at = @At("HEAD"), cancellable = true)
-	private void bclib_surfaceRule(CallbackInfoReturnable<SurfaceRules.RuleSource> info) {
-		if (bclib_surfaceRule != null) {
-			info.setReturnValue(bclib_surfaceRule);
 		}
 	}
+	
+	@Override
+	public void addCustomRules(List<RuleSource> rules) {
+		RuleSource org = getOriginalSurfaceRule();
+		if (org instanceof SurfaceRules.SequenceRuleSource sequenceRule){
+			List<RuleSource> currentSequence = sequenceRule.sequence();
+			rules = rules.stream().filter(r -> currentSequence.indexOf(r)<0).collect(Collectors.toList());
+			rules.addAll(sequenceRule.sequence());
+		} else {
+			rules.add(org);
+		}
+		setSurfaceRule(SurfaceRules.sequence(rules.toArray(new RuleSource[rules.size()])));
+	}
+	
+	void setSurfaceRule(SurfaceRules.RuleSource surfaceRule) {
+		if (bclib_originalSurfaceRule == null){
+			bclib_originalSurfaceRule = this.surfaceRule;
+		}
+		this.surfaceRule = surfaceRule;
+	}
+	
+	RuleSource getOriginalSurfaceRule() {
+		if (bclib_originalSurfaceRule ==null) {
+			return surfaceRule;
+		}
+		
+		return bclib_originalSurfaceRule;
+	}
+	
+//	@Inject(method = "surfaceRule", at = @At("HEAD"), cancellable = true)
+//	private void bclib_surfaceRule(CallbackInfoReturnable<SurfaceRules.RuleSource> info) {
+//		if (bclib_surfaceRule != null) {
+//			info.setReturnValue(bclib_surfaceRule);
+//		}
+//	}
 }

src/main/resources/bclib.accesswidener

@@ -6,3 +6,4 @@ accessible    class    net/minecraft/world/level/levelgen/SurfaceRules$Context
 accessible    class    net/minecraft/world/level/levelgen/SurfaceRules$Condition
 accessible    class    net/minecraft/world/level/levelgen/SurfaceRules$LazyXZCondition
 accessible    class    net/minecraft/world/level/levelgen/SurfaceRules$LazyCondition
+accessible    class    net/minecraft/world/level/levelgen/SurfaceRules$SequenceRuleSource