From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Thu, 13 Jan 2022 23:05:53 -0800
Subject: [PATCH] Add missing structure set seed configs

The 4 missing structure set seed configs are strongholds, mineshafts,
buried treasure, and ancient cities.

Strongholds use a ring placement scheme which isn't random so they
utilize the world seed by default, this adds a config to override it
for just generating the ring positions.

Mineshafts and Buried Treasure structure sets are special cases
where the "salt" that can be defined for them via datapacks has 0
effect because the difference between the spacing and separation is 1
which is used as the upper bound in the random with salt. So the random
always returns the same int (0) so the salt has no effect. This adds
seeds/salts to the frequency reducer which has a similar effect.

Co-authored-by: William Blake Galbreath <blake.galbreath@gmail.com>

diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
index 95dd058fca280a1e16f3d327be2aabeab91be534..7e9c388179c75a233d9b179ea1e00428ac65ee99 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
@@ -570,7 +570,7 @@ public abstract class ChunkGenerator {
                 }
             }
 
-            if (structureplacement.isStructureChunk(placementCalculator, chunkcoordintpair.x, chunkcoordintpair.z)) {
+            if (structureplacement.isStructureChunk(placementCalculator, chunkcoordintpair.x, chunkcoordintpair.z, structureplacement instanceof net.minecraft.world.level.chunk.ChunkGeneratorStructureState.KeyedRandomSpreadStructurePlacement keyed ? keyed.key : null)) { // Paper - add missing structure set configs
                 if (list.size() == 1) {
                     this.tryGenerateStructure((StructureSet.StructureSelectionEntry) list.get(0), structureAccessor, registryManager, randomstate, structureTemplateManager, placementCalculator.getLevelSeed(), chunk, chunkcoordintpair, sectionposition);
                 } else {
diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkGeneratorStructureState.java b/src/main/java/net/minecraft/world/level/chunk/ChunkGeneratorStructureState.java
index a310bfbf0d08187375ea17f4b04b276a0b7d0b9f..51a05900d02dc116ea215730713cd2cf2a4f1c23 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkGeneratorStructureState.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkGeneratorStructureState.java
@@ -50,13 +50,14 @@ public class ChunkGeneratorStructureState {
     private final Map<ConcentricRingsStructurePlacement, CompletableFuture<List<ChunkPos>>> ringPositions = new Object2ObjectArrayMap();
     private boolean hasGeneratedPositions;
     private final List<Holder<StructureSet>> possibleStructureSets;
+    public final SpigotWorldConfig conf; // Paper
 
     public static ChunkGeneratorStructureState createForFlat(RandomState randomstate, long i, BiomeSource worldchunkmanager, Stream<Holder<StructureSet>> stream, SpigotWorldConfig conf) { // Spigot
         List<Holder<StructureSet>> list = stream.filter((holder) -> {
             return ChunkGeneratorStructureState.hasBiomesForStructureSet((StructureSet) holder.value(), worldchunkmanager);
         }).toList();
 
-        return new ChunkGeneratorStructureState(randomstate, worldchunkmanager, i, 0L, ChunkGeneratorStructureState.injectSpigot(list, conf)); // Spigot
+        return new ChunkGeneratorStructureState(randomstate, worldchunkmanager, i, 0L, ChunkGeneratorStructureState.injectSpigot(list, conf), conf); // Spigot
     }
 
     public static ChunkGeneratorStructureState createForNormal(RandomState randomstate, long i, BiomeSource worldchunkmanager, HolderLookup<StructureSet> holderlookup, SpigotWorldConfig conf) { // Spigot
@@ -64,14 +65,24 @@ public class ChunkGeneratorStructureState {
             return ChunkGeneratorStructureState.hasBiomesForStructureSet((StructureSet) holder_c.value(), worldchunkmanager);
         }).collect(Collectors.toUnmodifiableList());
 
-        return new ChunkGeneratorStructureState(randomstate, worldchunkmanager, i, i, ChunkGeneratorStructureState.injectSpigot(list, conf)); // Spigot
+        return new ChunkGeneratorStructureState(randomstate, worldchunkmanager, i, i, ChunkGeneratorStructureState.injectSpigot(list, conf), conf); // Spigot
     }
+    // Paper start - horrible hack because spigot creates a ton of direct Holders which lose track of the identifying key
+    public static final class KeyedRandomSpreadStructurePlacement extends RandomSpreadStructurePlacement {
+        public final net.minecraft.resources.ResourceKey<StructureSet> key;
+        public KeyedRandomSpreadStructurePlacement(net.minecraft.resources.ResourceKey<StructureSet> key, net.minecraft.core.Vec3i locateOffset, FrequencyReductionMethod frequencyReductionMethod, float frequency, int salt, java.util.Optional<StructurePlacement.ExclusionZone> exclusionZone, int spacing, int separation, net.minecraft.world.level.levelgen.structure.placement.RandomSpreadType spreadType) {
+            super(locateOffset, frequencyReductionMethod, frequency, salt, exclusionZone, spacing, separation, spreadType);
+            this.key = key;
+        }
+    }
+    // Paper end
 
     // Spigot start
     private static List<Holder<StructureSet>> injectSpigot(List<Holder<StructureSet>> list, SpigotWorldConfig conf) {
         return list.stream().map((holder) -> {
             StructureSet structureset = holder.value();
-            if (structureset.placement() instanceof RandomSpreadStructurePlacement randomConfig) {
+            final Holder<StructureSet> newHolder; // Paper
+            if (structureset.placement() instanceof RandomSpreadStructurePlacement randomConfig && holder.unwrapKey().orElseThrow().location().getNamespace().equals(net.minecraft.resources.ResourceLocation.DEFAULT_NAMESPACE)) { // Paper - check namespace cause datapacks could add structure sets with the same path
                 String name = holder.unwrapKey().orElseThrow().location().getPath();
                 int seed = randomConfig.salt;
 
@@ -118,11 +129,21 @@ public class ChunkGeneratorStructureState {
                     case "villages":
                         seed = conf.villageSeed;
                         break;
+                    // Paper start
+                    case "ancient_cities":
+                        seed = conf.ancientCitySeed;
+                        break;
+                    // Paper end
                 }
 
-                structureset = new StructureSet(structureset.structures(), new RandomSpreadStructurePlacement(randomConfig.locateOffset, randomConfig.frequencyReductionMethod, randomConfig.frequency, seed, randomConfig.exclusionZone, randomConfig.spacing(), randomConfig.separation(), randomConfig.spreadType()));
+            // Paper start
+                structureset = new StructureSet(structureset.structures(), new KeyedRandomSpreadStructurePlacement(holder.unwrapKey().orElseThrow(), randomConfig.locateOffset, randomConfig.frequencyReductionMethod, randomConfig.frequency, seed, randomConfig.exclusionZone, randomConfig.spacing(), randomConfig.separation(), randomConfig.spreadType()));
+                newHolder = Holder.direct(structureset); // I really wish we didn't have to do this here
+            } else {
+                newHolder = holder;
             }
-            return Holder.direct(structureset);
+            return newHolder;
+            // Paper end
         }).collect(Collectors.toUnmodifiableList());
     }
     // Spigot end
@@ -139,12 +160,13 @@ public class ChunkGeneratorStructureState {
         return stream.anyMatch(set::contains);
     }
 
-    private ChunkGeneratorStructureState(RandomState noiseConfig, BiomeSource biomeSource, long structureSeed, long concentricRingSeed, List<Holder<StructureSet>> structureSets) {
+    private ChunkGeneratorStructureState(RandomState noiseConfig, BiomeSource biomeSource, long structureSeed, long concentricRingSeed, List<Holder<StructureSet>> structureSets, SpigotWorldConfig conf) { // Paper
         this.randomState = noiseConfig;
         this.levelSeed = structureSeed;
         this.biomeSource = biomeSource;
         this.concentricRingsSeed = concentricRingSeed;
         this.possibleStructureSets = structureSets;
+        this.conf = conf; // Paper
     }
 
     public List<Holder<StructureSet>> possibleStructureSets() {
@@ -198,7 +220,13 @@ public class ChunkGeneratorStructureState {
             HolderSet<Biome> holderset = placement.preferredBiomes();
             RandomSource randomsource = RandomSource.create();
 
+            // Paper start
+            if (this.conf.strongholdSeed != null && structureSetEntry.is(net.minecraft.world.level.levelgen.structure.BuiltinStructureSets.STRONGHOLDS)) {
+                randomsource.setSeed(this.conf.strongholdSeed);
+            } else {
+            // Paper end
             randomsource.setSeed(this.concentricRingsSeed);
+            } // Paper
             double d0 = randomsource.nextDouble() * 3.141592653589793D * 2.0D;
             int l = 0;
             int i1 = 0;
@@ -275,7 +303,7 @@ public class ChunkGeneratorStructureState {
 
         for (int l = centerChunkX - chunkCount; l <= centerChunkX + chunkCount; ++l) {
             for (int i1 = centerChunkZ - chunkCount; i1 <= centerChunkZ + chunkCount; ++i1) {
-                if (structureplacement.isStructureChunk(this, l, i1)) {
+                if (structureplacement.isStructureChunk(this, l, i1, structureplacement instanceof KeyedRandomSpreadStructurePlacement keyed ? keyed.key : null)) { // Paper - add missing structure set configs
                     return true;
                 }
             }
diff --git a/src/main/java/net/minecraft/world/level/levelgen/structure/placement/StructurePlacement.java b/src/main/java/net/minecraft/world/level/levelgen/structure/placement/StructurePlacement.java
index 65dcb14241baadb2c9f8f16919d7b562198ad9c3..594a2dd3b1d4c29c969d1992b8e93795da00e682 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/structure/placement/StructurePlacement.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/structure/placement/StructurePlacement.java
@@ -59,10 +59,24 @@ public abstract class StructurePlacement {
         return this.exclusionZone;
     }
 
+    @Deprecated @io.papermc.paper.annotation.DoNotUse // Paper
     public boolean isStructureChunk(ChunkGeneratorStructureState calculator, int chunkX, int chunkZ) {
+        // Paper start - add missing structure set configs
+        return this.isStructureChunk(calculator, chunkX, chunkZ, null);
+    }
+    public boolean isStructureChunk(ChunkGeneratorStructureState calculator, int chunkX, int chunkZ, @org.jetbrains.annotations.Nullable net.minecraft.resources.ResourceKey<StructureSet> structureSetKey) {
+        Integer saltOverride = null;
+        if (structureSetKey != null) {
+            if (structureSetKey == net.minecraft.world.level.levelgen.structure.BuiltinStructureSets.MINESHAFTS) {
+                saltOverride = calculator.conf.mineshaftSeed;
+            } else if (structureSetKey == net.minecraft.world.level.levelgen.structure.BuiltinStructureSets.BURIED_TREASURES) {
+                saltOverride = calculator.conf.buriedTreasureSeed;
+            }
+        }
+        // Paper end
         if (!this.isPlacementChunk(calculator, chunkX, chunkZ)) {
             return false;
-        } else if (this.frequency < 1.0F && !this.frequencyReductionMethod.shouldGenerate(calculator.getLevelSeed(), this.salt, chunkX, chunkZ, this.frequency)) {
+        } else if (this.frequency < 1.0F && !this.frequencyReductionMethod.shouldGenerate(calculator.getLevelSeed(), this.salt, chunkX, chunkZ, this.frequency, saltOverride)) { // Paper
             return false;
         } else {
             return !this.exclusionZone.isPresent() || !this.exclusionZone.get().isPlacementForbidden(calculator, chunkX, chunkZ);
@@ -77,25 +91,31 @@ public abstract class StructurePlacement {
 
     public abstract StructurePlacementType<?> type();
 
-    private static boolean probabilityReducer(long seed, int salt, int chunkX, int chunkZ, float frequency) {
+    private static boolean probabilityReducer(long seed, int salt, int chunkX, int chunkZ, float frequency, @org.jetbrains.annotations.Nullable Integer saltOverride) { // Paper - ignore here
         WorldgenRandom worldgenRandom = new WorldgenRandom(new LegacyRandomSource(0L));
         worldgenRandom.setLargeFeatureWithSalt(seed, salt, chunkX, chunkZ);
         return worldgenRandom.nextFloat() < frequency;
     }
 
-    private static boolean legacyProbabilityReducerWithDouble(long seed, int salt, int chunkX, int chunkZ, float frequency) {
+    private static boolean legacyProbabilityReducerWithDouble(long seed, int salt, int chunkX, int chunkZ, float frequency, @org.jetbrains.annotations.Nullable Integer saltOverride) { // Paper
         WorldgenRandom worldgenRandom = new WorldgenRandom(new LegacyRandomSource(0L));
+        if (saltOverride == null) { // Paper
         worldgenRandom.setLargeFeatureSeed(seed, chunkX, chunkZ);
+        // Paper start
+        } else {
+            worldgenRandom.setLargeFeatureWithSalt(seed, chunkX, chunkZ, saltOverride);
+        }
+        // Paper end
         return worldgenRandom.nextDouble() < (double)frequency;
     }
 
-    private static boolean legacyArbitrarySaltProbabilityReducer(long seed, int salt, int chunkX, int chunkZ, float frequency) {
+    private static boolean legacyArbitrarySaltProbabilityReducer(long seed, int salt, int chunkX, int chunkZ, float frequency, @org.jetbrains.annotations.Nullable Integer saltOverride) { // Paper
         WorldgenRandom worldgenRandom = new WorldgenRandom(new LegacyRandomSource(0L));
-        worldgenRandom.setLargeFeatureWithSalt(seed, chunkX, chunkZ, 10387320);
+        worldgenRandom.setLargeFeatureWithSalt(seed, chunkX, chunkZ, saltOverride != null ? saltOverride : HIGHLY_ARBITRARY_RANDOM_SALT); // Paper
         return worldgenRandom.nextFloat() < frequency;
     }
 
-    private static boolean legacyPillagerOutpostReducer(long seed, int salt, int chunkX, int chunkZ, float frequency) {
+    private static boolean legacyPillagerOutpostReducer(long seed, int salt, int chunkX, int chunkZ, float frequency, @org.jetbrains.annotations.Nullable Integer saltOverride) { // Paper - ignore here
         int i = chunkX >> 4;
         int j = chunkZ >> 4;
         WorldgenRandom worldgenRandom = new WorldgenRandom(new LegacyRandomSource(0L));
@@ -118,7 +138,7 @@ public abstract class StructurePlacement {
 
     @FunctionalInterface
     public interface FrequencyReducer {
-        boolean shouldGenerate(long seed, int salt, int chunkX, int chunkZ, float chance);
+        boolean shouldGenerate(long seed, int salt, int chunkX, int chunkZ, float chance, @org.jetbrains.annotations.Nullable Integer saltOverride); // Paper
     }
 
     public static enum FrequencyReductionMethod implements StringRepresentable {
@@ -136,8 +156,8 @@ public abstract class StructurePlacement {
             this.reducer = generationPredicate;
         }
 
-        public boolean shouldGenerate(long seed, int salt, int chunkX, int chunkZ, float chance) {
-            return this.reducer.shouldGenerate(seed, salt, chunkX, chunkZ, chance);
+        public boolean shouldGenerate(long seed, int salt, int chunkX, int chunkZ, float chance, @org.jetbrains.annotations.Nullable Integer saltOverride) { // Paper
+            return this.reducer.shouldGenerate(seed, salt, chunkX, chunkZ, chance, saltOverride); // Paper
         }
 
         @Override
diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
index 6bcc46795d1f78746192cc107c4a1f61580ec3c5..5503ad6a93d331771a0e92c0da6adedf2ac81aff 100644
--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
+++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
@@ -362,6 +362,16 @@ public class SpigotWorldConfig
     public int mansionSeed;
     public int fossilSeed;
     public int portalSeed;
+    // Paper start - add missing structure set configs
+    public int ancientCitySeed;
+    public int buriedTreasureSeed;
+    public Integer mineshaftSeed;
+    public Long strongholdSeed;
+    private <N extends Number> N getSeed(String path, java.util.function.Function<String, N> toNumberFunc) {
+        final String value = this.getString(path, "default");
+        return org.apache.commons.lang3.math.NumberUtils.isParsable(value) ? toNumberFunc.apply(value) : null;
+    }
+    // Paper end
     private void initWorldGenSeeds()
     {
         this.villageSeed = this.getInt( "seed-village", 10387312 );
@@ -379,6 +389,12 @@ public class SpigotWorldConfig
         this.mansionSeed = this.getInt( "seed-mansion", 10387319 );
         this.fossilSeed = this.getInt( "seed-fossil", 14357921 );
         this.portalSeed = this.getInt( "seed-portal", 34222645 );
+        // Paper start - add missing structure set configs
+        this.ancientCitySeed = this.getInt("seed-ancientcity", 20083232);
+        this.buriedTreasureSeed = this.getInt("seed-buriedtreasure", 10387320); // StructurePlacement#HIGHLY_ARBITRARY_RANDOM_SALT
+        this.mineshaftSeed = this.getSeed("seed-mineshaft", Integer::parseInt);
+        this.strongholdSeed = this.getSeed("seed-stronghold", Long::parseLong);
+        // Paper end
         this.log( "Custom Map Seeds:  Village: " + this.villageSeed + " Desert: " + this.desertSeed + " Igloo: " + this.iglooSeed + " Jungle: " + this.jungleSeed + " Swamp: " + this.swampSeed + " Monument: " + this.monumentSeed
                 + " Ocean: " + this.oceanSeed + " Shipwreck: " + this.shipwreckSeed + " End City: " + this.endCitySeed + " Slime: " + this.slimeSeed + " Nether: " + this.netherSeed + " Mansion: " + this.mansionSeed + " Fossil: " + this.fossilSeed + " Portal: " + this.portalSeed );
     }
