Backport feature search improvement from 1.17 (Fixes #2312) (#4771)

Spigot-Server-Patches/0600-Seed-based-feature-search.patch

@@ -0,0 +1,97 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Phoenix616 <mail@moep.tv>
+Date: Mon, 13 Jan 2020 15:40:32 +0100
+Subject: [PATCH] Seed based feature search
+
+This tries to work around the issue where the server will load
+surrounding chunks up to a radius of 100 chunks in order to search for
+features e.g. when running the /locate command or for treasure maps
+(issue #2312).
+This is done by backporting Mojang's change in 1.17 which makes it so
+that the biome (generated by the seed) is checked first if the feature
+can be generated before actually to load the chunk.
+
+The only downside of this is that it breaks once the seed or generator
+changes but this should usually not happen. A config option to disable
+this improvement is added though in case that should ever be necessary.
+
+diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+index 9a0ade5875c34487a65f82f9380f9d25b4432586..ff0e4447b6574e91bf8815de4e04ce881ed7026d 100644
+--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
++++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+@@ -331,6 +331,12 @@ public class PaperWorldConfig {
+         }
+     }
+ 
++    public boolean seedBasedFeatureSearch = true;
++    private void seedBasedFeatureSearch() {
++        seedBasedFeatureSearch = getBoolean("seed-based-feature-search", seedBasedFeatureSearch);
++        log("Feature search is based on seed: " + seedBasedFeatureSearch);
++    }
++
+     public int maxCollisionsPerEntity;
+     private void maxEntityCollision() {
+         maxCollisionsPerEntity = getInt( "max-entity-collisions", this.spigotConfig.getInt("max-entity-collisions", 8) );
+diff --git a/src/main/java/net/minecraft/server/BiomeManager.java b/src/main/java/net/minecraft/server/BiomeManager.java
+index 5c992812e0c066109763a30c9399e5b71a335398..fddcd205ee4d841546463913f56f998059cba248 100644
+--- a/src/main/java/net/minecraft/server/BiomeManager.java
++++ b/src/main/java/net/minecraft/server/BiomeManager.java
+@@ -22,6 +22,7 @@ public class BiomeManager {
+         return new BiomeManager(worldchunkmanager, this.b, this.c);
+     }
+ 
++    public BiomeBase getBiome(BlockPosition blockposition) { return a(blockposition); } // Paper - OBFHELPER
+     public BiomeBase a(BlockPosition blockposition) {
+         return this.c.a(this.b, blockposition.getX(), blockposition.getY(), blockposition.getZ(), this.a);
+     }
+diff --git a/src/main/java/net/minecraft/server/ChunkCoordIntPair.java b/src/main/java/net/minecraft/server/ChunkCoordIntPair.java
+index dcaf9f8574a9c913b64ba3a1d8b02220db720225..271fddbbf73ca5c0e4e2722d7246c14b778d6072 100644
+--- a/src/main/java/net/minecraft/server/ChunkCoordIntPair.java
++++ b/src/main/java/net/minecraft/server/ChunkCoordIntPair.java
+@@ -67,10 +67,12 @@ public class ChunkCoordIntPair {
+         }
+     }
+ 
++    public int getBlockX() { return d(); } // Paper - OBFHELPER
+     public int d() {
+         return this.x << 4;
+     }
+ 
++    public int getBlockZ() { return e(); } // Paper - OBFHELPER
+     public int e() {
+         return this.z << 4;
+     }
+diff --git a/src/main/java/net/minecraft/server/StructureGenerator.java b/src/main/java/net/minecraft/server/StructureGenerator.java
+index c3bd58069d8dbdf36f70f1dafd7c24000f31708b..a62c87bceab2c9700a7b3925f208b0ffa2b9b393 100644
+--- a/src/main/java/net/minecraft/server/StructureGenerator.java
++++ b/src/main/java/net/minecraft/server/StructureGenerator.java
+@@ -143,6 +143,14 @@ public abstract class StructureGenerator<C extends WorldGenFeatureConfiguration>
+                             int j2 = i1 + k * l1;
+                             ChunkCoordIntPair chunkcoordintpair = this.a(structuresettingsfeature, j, seededrandom, i2, j2);
+                             if (!iworldreader.getWorldBorder().isChunkInBounds(chunkcoordintpair.x, chunkcoordintpair.z)) { continue; } // Paper
++                            // Paper start - seed based feature search
++                            if (structuremanager.getWorld().paperConfig.seedBasedFeatureSearch) {
++                                BiomeBase biomeBase = structuremanager.getWorld().getBiomeManager().getBiome(new BlockPosition(chunkcoordintpair.getBlockX() + 9, 0, chunkcoordintpair.getBlockZ() + 9));
++                                if (!biomeBase.e().a(this)) {
++                                    continue;
++                                }
++                            }
++                            // Paper end
+                             IChunkAccess ichunkaccess = iworldreader.getChunkAt(chunkcoordintpair.x, chunkcoordintpair.z, ChunkStatus.STRUCTURE_STARTS);
+                             StructureStart<?> structurestart = structuremanager.a(SectionPosition.a(ichunkaccess.getPos(), 0), this, ichunkaccess);
+ 
+diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
+index d64d94b8c329ddce27151afc012ecfe26b5ee707..f260da1fd253ebd233d741809acf8a020779744b 100644
+--- a/src/main/java/net/minecraft/server/World.java
++++ b/src/main/java/net/minecraft/server/World.java
+@@ -1451,8 +1451,8 @@ public abstract class World implements GeneratorAccess, AutoCloseable {
+         return this.methodProfiler;
+     }
+ 
+-    @Override
+-    public BiomeManager d() {
++    public BiomeManager getBiomeManager() { return d(); } // Paper - OBFHELPER
++    @Override public BiomeManager d() {
+         return this.biomeManager;
+     }
+