From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: dfsek <dfsek@protonmail.com>
Date: Wed, 16 Sep 2020 01:12:29 -0700
Subject: [PATCH] Add StructuresLocateEvent

Co-authored-by: Jake Potrebic <jake.m.potrebic@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 0acf8b62ddb5e005f8f861558934e8afc8673725..416b1afcbab093f45900a4d55708609ba5a7de7a 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
@@ -127,6 +127,24 @@ public abstract class ChunkGenerator {
 
     @Nullable
     public Pair<BlockPos, Holder<Structure>> findNearestMapStructure(ServerLevel world, HolderSet<Structure> structures, BlockPos center, int radius, boolean skipReferencedStructures) {
+        // Paper start - StructuresLocateEvent
+        final org.bukkit.World bukkitWorld = world.getWorld();
+        final org.bukkit.Location origin = io.papermc.paper.util.MCUtil.toLocation(world, center);
+        final List<org.bukkit.generator.structure.Structure> apiStructures = structures.stream().map(Holder::value).map(nms -> org.bukkit.craftbukkit.generator.structure.CraftStructure.minecraftToBukkit(nms)).toList();
+        if (!apiStructures.isEmpty()) {
+            final io.papermc.paper.event.world.StructuresLocateEvent event = new io.papermc.paper.event.world.StructuresLocateEvent(bukkitWorld, origin, apiStructures, radius, skipReferencedStructures);
+            if (!event.callEvent()) {
+                return null;
+            }
+            if (event.getResult() != null) {
+                return Pair.of(io.papermc.paper.util.MCUtil.toBlockPos(event.getResult().pos()), world.registryAccess().lookupOrThrow(Registries.STRUCTURE).wrapAsHolder(org.bukkit.craftbukkit.generator.structure.CraftStructure.bukkitToMinecraft(event.getResult().structure())));
+            }
+            center = io.papermc.paper.util.MCUtil.toBlockPosition(event.getOrigin());
+            radius = event.getRadius();
+            skipReferencedStructures = event.shouldFindUnexplored();
+            structures = HolderSet.direct(api -> world.registryAccess().lookupOrThrow(Registries.STRUCTURE).wrapAsHolder(org.bukkit.craftbukkit.generator.structure.CraftStructure.bukkitToMinecraft(api)), event.getStructures());
+        }
+        // Paper end
         ChunkGeneratorStructureState chunkgeneratorstructurestate = world.getChunkSource().getGeneratorState();
         Map<StructurePlacement, Set<Holder<Structure>>> map = new Object2ObjectArrayMap();
         Iterator iterator = structures.iterator();