Paper/patches/removed/1.17/0187-PreCreatureSpawnEvent.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 14 Jan 2018 17:01:31 -0500
Subject: [PATCH] PreCreatureSpawnEvent
1.17: Has to be looked into more
Adds an event to fire before an Entity is created, so that plugins that need to cancel
CreatureSpawnEvent can do so from this event instead.

Cancelling CreatureSpawnEvent rapidly causes a lot of garbage collection and CPU waste
as it's done after the Entity object has been fully created.

Mob Limiting plugins and blanket "ban this type of monster" plugins should use this event
instead and save a lot of server resources.

See: https://github.com/PaperMC/Paper/issues/917

diff --git a/src/main/java/net/minecraft/world/entity/EntityType.java b/src/main/java/net/minecraft/world/entity/EntityType.java
index e3d92d1d35911b2960a7ca82bd4f324d285d0533..e39d950783599b01271bdb7e67fe68b46af0c49c 100644
--- a/src/main/java/net/minecraft/world/entity/EntityType.java
+++ b/src/main/java/net/minecraft/world/entity/EntityType.java
@@ -17,6 +17,7 @@ import net.minecraft.nbt.ListTag;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.TranslatableComponent;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MCUtil;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.tags.BlockTags;
@@ -317,6 +318,20 @@ public class EntityType<T extends Entity> {
 
     @Nullable
     public T spawnCreature(ServerLevel worldserver, @Nullable CompoundTag nbttagcompound, @Nullable Component ichatbasecomponent, @Nullable Player entityhuman, BlockPos blockposition, MobSpawnType enummobspawn, boolean flag, boolean flag1, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason spawnReason) {
+        // Paper start - Call PreCreatureSpawnEvent
+        org.bukkit.entity.EntityType type = org.bukkit.entity.EntityType.fromName(EntityType.getKey(this).getPath());
+        if (type != null) {
+            com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent event;
+            event = new com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent(
+                MCUtil.toLocation(worldserver, blockposition),
+                type,
+                spawnReason
+            );
+            if (!event.callEvent()) {
+                return null;
+            }
+        }
+        // Paper end
         T t0 = this.create(worldserver, nbttagcompound, ichatbasecomponent, entityhuman, blockposition, enummobspawn, flag, flag1);
 
         if (t0 != null) {
diff --git a/src/main/java/net/minecraft/world/entity/ai/sensing/GolemSensor.java b/src/main/java/net/minecraft/world/entity/ai/sensing/GolemSensor.java
index f3a7807a20b279056d5640ab02aa77f7b1dabc2a..880d69bad933294a2cfdea9adb3e648e29eb42be 100644
--- a/src/main/java/net/minecraft/world/entity/ai/sensing/GolemSensor.java
+++ b/src/main/java/net/minecraft/world/entity/ai/sensing/GolemSensor.java
@@ -33,8 +33,8 @@ public class GolemSensor extends Sensor<LivingEntity> {
         Optional<List<LivingEntity>> optional = entityliving.getBrain().getMemory(MemoryModuleType.MOBS);
 
         if (optional.isPresent()) {
-            boolean flag = ((List) optional.get()).stream().anyMatch((entityliving1) -> {
-                return entityliving1.getEntityType().equals(EntityType.IRON_GOLEM);
+            boolean flag = optional.get().stream().anyMatch((entityliving1) -> { // Paper - decompile fixes
+                return entityliving1.getType().equals(EntityType.IRON_GOLEM);
             });
 
             if (flag) {
@@ -44,6 +44,7 @@ public class GolemSensor extends Sensor<LivingEntity> {
         }
     }
 
+    public static void setDetectedRecently(LivingEntity entityLiving) { golemDetected(entityLiving); } // Paper - OBFHELPER
     public static void golemDetected(LivingEntity entityliving) {
         entityliving.getBrain().setMemoryWithExpiry(MemoryModuleType.GOLEM_DETECTED_RECENTLY, true, 600L);
     }
diff --git a/src/main/java/net/minecraft/world/entity/npc/Villager.java b/src/main/java/net/minecraft/world/entity/npc/Villager.java
index a66fab2e04a5d87ced139ed15d2434c5ffcec695..eed6265dc8275921a18fc5f4970ba131ba782132 100644
--- a/src/main/java/net/minecraft/world/entity/npc/Villager.java
+++ b/src/main/java/net/minecraft/world/entity/npc/Villager.java
@@ -30,6 +30,7 @@ import net.minecraft.network.protocol.game.DebugPackets;
 import net.minecraft.network.syncher.EntityDataAccessor;
 import net.minecraft.network.syncher.EntityDataSerializers;
 import net.minecraft.network.syncher.SynchedEntityData;
+import net.minecraft.server.MCUtil;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.sounds.SoundEvent;
@@ -942,6 +943,21 @@ public class Villager extends AbstractVillager implements ReputationEventHandler
             BlockPos blockposition1 = this.findSpawnPositionForGolemInColumn(blockposition, d0, d1);
 
             if (blockposition1 != null) {
+                // Paper start - Call PreCreatureSpawnEvent
+                com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent event;
+                event = new com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent(
+                    MCUtil.toLocation(level, blockposition1),
+                    org.bukkit.entity.EntityType.IRON_GOLEM,
+                    org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.VILLAGE_DEFENSE
+                );
+                if (!event.callEvent()) {
+                    if (event.shouldAbortSpawn()) {
+                        GolemSensor.golemDetected(this); // Set Golem Last Seen to stop it from spawning another one
+                        return null;
+                    }
+                    break;
+                }
+                // Paper end
                 IronGolem entityirongolem = (IronGolem) EntityType.IRON_GOLEM.create(world, (CompoundTag) null, (Component) null, (Player) null, blockposition1, MobSpawnType.MOB_SUMMONED, false, false);
 
                 if (entityirongolem != null) {
diff --git a/src/main/java/net/minecraft/world/level/BaseSpawner.java b/src/main/java/net/minecraft/world/level/BaseSpawner.java
index 4582fc1bb767214241568fbc22b0ee2cbf3322e0..ac572eba10a7239d71dfae060f623b076d4252ce 100644
--- a/src/main/java/net/minecraft/world/level/BaseSpawner.java
+++ b/src/main/java/net/minecraft/world/level/BaseSpawner.java
@@ -12,6 +12,7 @@ import net.minecraft.core.particles.ParticleTypes;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.ListTag;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MCUtil;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.util.StringUtil;
 import net.minecraft.util.WeighedRandom;
@@ -125,6 +126,27 @@ public abstract class BaseSpawner {
                         ServerLevel worldserver = (ServerLevel) world;
 
                         if (SpawnPlacements.checkSpawnRules((EntityType) optional.get(), worldserver, MobSpawnType.SPAWNER, new BlockPos(d3, d4, d5), world.getRandom())) {
+                            // Paper start
+                            EntityType<?> entityType = optional.get();
+                            String key = EntityType.getKey(entityType).getPath();
+
+                            org.bukkit.entity.EntityType type = org.bukkit.entity.EntityType.fromName(key);
+                            if (type != null) {
+                                com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent event;
+                                event = new com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent(
+                                    MCUtil.toLocation(world, d3, d4, d5),
+                                    type,
+                                    org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.SPAWNER
+                                );
+                                if (!event.callEvent()) {
+                                    flag = true;
+                                    if (event.shouldAbortSpawn()) {
+                                        break;
+                                    }
+                                    continue;
+                                }
+                            }
+                            // Paper end
                             Entity entity = EntityType.loadEntityRecursive(nbttagcompound, world, (entity1) -> {
                                 entity1.moveTo(d3, d4, d5, entity1.yRot, entity1.xRot);
                                 return entity1;
diff --git a/src/main/java/net/minecraft/world/level/NaturalSpawner.java b/src/main/java/net/minecraft/world/level/NaturalSpawner.java
index a19ac1cb7e4d8d478648a048b2bfa0daf85a80c9..8a71eaf2855be0d415d1f7b18dbec98353fe5b47 100644
--- a/src/main/java/net/minecraft/world/level/NaturalSpawner.java
+++ b/src/main/java/net/minecraft/world/level/NaturalSpawner.java
@@ -15,6 +15,7 @@ import net.minecraft.core.Direction;
 import net.minecraft.core.Position;
 import net.minecraft.core.Registry;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.MCUtil;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.tags.BlockTags;
 import net.minecraft.tags.FluidTags;
@@ -214,9 +215,16 @@ public final class NaturalSpawner {
                                         j1 = biomesettingsmobs_c.minCount + world.random.nextInt(1 + biomesettingsmobs_c.maxCount - biomesettingsmobs_c.minCount);
                                     }
 
-                                    if (isValidSpawnPostitionForType(world, group, structuremanager, chunkgenerator, biomesettingsmobs_c, blockposition_mutableblockposition, d2) && checker.test(biomesettingsmobs_c.type, blockposition_mutableblockposition, chunk)) {
+                                    // Paper start
+                                    Boolean doSpawning = a(world, group, structuremanager, chunkgenerator, biomesettingsmobs_c, blockposition_mutableblockposition, d2);
+                                    if (doSpawning == null) {
+                                        return;
+                                    }
+                                    if (doSpawning && checker.test(biomesettingsmobs_c.type, blockposition_mutableblockposition, chunk)) {
+                                        // Paper end
                                         Mob entityinsentient = getMobForSpawn(world, biomesettingsmobs_c.type);
 
+
                                         if (entityinsentient == null) {
                                             return;
                                         }
@@ -269,17 +277,33 @@ public final class NaturalSpawner {
         }
     }
 
-    private static boolean isValidSpawnPostitionForType(ServerLevel world, MobCategory group, StructureFeatureManager structureAccessor, ChunkGenerator chunkGenerator, MobSpawnSettings.SpawnerData spawnEntry, BlockPos.MutableBlockPos pos, double squaredDistance) {
-        EntityType<?> entitytypes = spawnEntry.type;
+    private static Boolean a(ServerLevel worldserver, MobCategory enumcreaturetype, StructureFeatureManager structuremanager, ChunkGenerator chunkgenerator, MobSpawnSettings.SpawnerData biomesettingsmobs_c, BlockPos.MutableBlockPos blockposition_mutableblockposition, double d0) { // Paper
+        EntityType<?> entitytypes = biomesettingsmobs_c.type;
+        // Paper start
+        com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent event;
+        org.bukkit.entity.EntityType type = org.bukkit.entity.EntityType.fromName(EntityType.getKey(entitytypes).getPath());
+        if (type != null) {
+            event = new com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent(
+                MCUtil.toLocation(worldserver, blockposition_mutableblockposition),
+                type, SpawnReason.NATURAL
+            );
+            if (!event.callEvent()) {
+                if (event.shouldAbortSpawn()) {
+                    return null;
+                }
+                return false;
+            }
+        }
+        // Paper end
 
         if (entitytypes.getCategory() == MobCategory.MISC) {
             return false;
-        } else if (!entitytypes.canSpawnFarFromPlayer() && squaredDistance > (double) (entitytypes.getCategory().getDespawnDistance() * entitytypes.getCategory().getDespawnDistance())) {
+        } else if (!entitytypes.canSpawnFarFromPlayer() && d0 > (double) (entitytypes.getCategory().getDespawnDistance() * entitytypes.getCategory().getDespawnDistance())) {
             return false;
-        } else if (entitytypes.canSummon() && canSpawnMobAt(world, structureAccessor, chunkGenerator, group, spawnEntry, (BlockPos) pos)) {
+        } else if (entitytypes.canSummon() && canSpawnMobAt(worldserver, structuremanager, chunkgenerator, enumcreaturetype, biomesettingsmobs_c, (BlockPos) blockposition_mutableblockposition)) {
             SpawnPlacements.Type entitypositiontypes_surface = SpawnPlacements.getPlacementType(entitytypes);
 
-            return !isSpawnPositionOk(entitypositiontypes_surface, (LevelReader) world, pos, entitytypes) ? false : (!SpawnPlacements.checkSpawnRules(entitytypes, world, MobSpawnType.NATURAL, pos, world.random) ? false : world.noCollision(entitytypes.getAABB((double) pos.getX() + 0.5D, (double) pos.getY(), (double) pos.getZ() + 0.5D)));
+            return !isSpawnPositionOk(entitypositiontypes_surface, (LevelReader) worldserver, blockposition_mutableblockposition, entitytypes) ? false : (!SpawnPlacements.checkSpawnRules(entitytypes, worldserver, MobSpawnType.NATURAL, blockposition_mutableblockposition, worldserver.random) ? false : worldserver.noCollision(entitytypes.getAABB((double) blockposition_mutableblockposition.getX() + 0.5D, (double) blockposition_mutableblockposition.getY(), (double) blockposition_mutableblockposition.getZ() + 0.5D)));
         } else {
             return false;
         }