Paper/patches/server/0808-Add-missing-structure-set-seed-configs.patch

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 cc79ca7ee770408ec59b1f6a3f4ec58e23bd2619..52264a583e79cc6adb9967aebac7f6b3ac129017 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
@@ -133,7 +133,7 @@ public abstract class ChunkGenerator {
     // Spigot start
     private Stream<StructureSet> possibleStructureSetsSpigot() {
         return this.possibleStructureSets().map(Holder::value).map((structureset) -> {
-            if (structureset.placement() instanceof RandomSpreadStructurePlacement randomConfig) {
+            if (structureset.placement() instanceof RandomSpreadStructurePlacement randomConfig && this.structureSets.getKey(structureset).getNamespace().equals(net.minecraft.resources.ResourceLocation.DEFAULT_NAMESPACE)) { // Paper - check namespace cause datapacks could add structure sets with the same path
                 String name = this.structureSets.getKey(structureset).getPath();
                 int seed = randomConfig.salt;
 
@@ -180,6 +180,11 @@ public abstract class ChunkGenerator {
                     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()));
@@ -236,7 +241,13 @@ public abstract class ChunkGenerator {
             HolderSet<Biome> holderset = concentricringsstructureplacement.preferredBiomes();
             RandomSource randomsource = RandomSource.create();
 
+            // Paper start
+            if (this.conf.strongholdSeed != null && this.structureSets.getResourceKey(holder).orElse(null) == net.minecraft.world.level.levelgen.structure.BuiltinStructureSets.STRONGHOLDS) {
+                randomsource.setSeed(this.conf.strongholdSeed);
+            } else {
             randomsource.setSeed(this instanceof FlatLevelSource ? 0L : randomstate.legacyLevelSeed());
+            }
+            // Paper end
             double d0 = randomsource.nextDouble() * 3.141592653589793D * 2.0D;
             int l = 0;
             int i1 = 0;
@@ -677,7 +688,7 @@ public abstract class ChunkGenerator {
 
             for (int i1 = chunkX - chunkRange; i1 <= chunkX + chunkRange; ++i1) {
                 for (int j1 = chunkZ - chunkRange; j1 <= chunkZ + chunkRange; ++j1) {
-                    if (structureplacement.isStructureChunk(this, noiseConfig, seed, i1, j1)) {
+                    if (structureplacement.isStructureChunk(this, noiseConfig, seed, i1, j1, structureSet.unwrapKey().map(ResourceKey::location).orElse(null))) { // Paper
                         return true;
                     }
                 }
@@ -764,7 +775,7 @@ public abstract class ChunkGenerator {
                 }
             }
 
-            if (structureplacement.isStructureChunk(this, noiseConfig, seed, chunkcoordintpair.x, chunkcoordintpair.z)) {
+            if (structureplacement.isStructureChunk(this, noiseConfig, seed, chunkcoordintpair.x, chunkcoordintpair.z, this.structureSets.getResourceKey(holder).map(ResourceKey::location).orElse(null))) { // Paper
                 if (list.size() == 1) {
                     this.tryGenerateStructure((StructureSet.StructureSelectionEntry) list.get(0), structureAccessor, registryManager, noiseConfig, structureTemplateManager, seed, chunk, chunkcoordintpair, sectionposition);
                 } else {
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 2fd1284c7f0d8e2cf35d03072089256d990b06eb..8ef0e9fa126cd96289bab48eaa06c2a1fbe4281e 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 +59,22 @@ public abstract class StructurePlacement {
         return this.exclusionZone;
     }
 
+    @Deprecated @io.papermc.paper.annotation.DoNotUse // Paper
     public boolean isStructureChunk(ChunkGenerator chunkGenerator, RandomState noiseConfig, long seed, int chunkX, int chunkZ) {
+        // Paper start - add missing structure set configs
+        return this.isStructureChunk(chunkGenerator, noiseConfig, seed, chunkX, chunkZ, null);
+    }
+    public boolean isStructureChunk(ChunkGenerator chunkGenerator, RandomState noiseConfig, long seed, int chunkX, int chunkZ, @org.jetbrains.annotations.Nullable net.minecraft.resources.ResourceLocation structureSetKey) {
+        Integer saltOverride = null;
+        if (net.minecraft.world.level.levelgen.structure.BuiltinStructureSets.MINESHAFTS.location().equals(structureSetKey)) {
+            saltOverride = chunkGenerator.conf.mineshaftSeed;
+        } else if (net.minecraft.world.level.levelgen.structure.BuiltinStructureSets.BURIED_TREASURES.location().equals(structureSetKey)) {
+            saltOverride = chunkGenerator.conf.buriedTreasureSeed;
+        }
+        // Paper end
         if (!this.isPlacementChunk(chunkGenerator, noiseConfig, seed, chunkX, chunkZ)) {
             return false;
-        } else if (this.frequency < 1.0F && !this.frequencyReductionMethod.shouldGenerate(seed, this.salt, chunkX, chunkZ, this.frequency)) {
+        } else if (this.frequency < 1.0F && !this.frequencyReductionMethod.shouldGenerate(seed, this.salt, chunkX, chunkZ, this.frequency, saltOverride)) { // Paper
             return false;
         } else {
             return !this.exclusionZone.isPresent() || !this.exclusionZone.get().isPlacementForbidden(chunkGenerator, noiseConfig, seed, chunkX, chunkZ);
@@ -77,25 +89,31 @@ 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 : 10387320); // 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 +136,7 @@ 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 +154,8 @@ 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 );
     }