Paper/patches/server/0675-Add-more-LimitedRegion-API.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: dfsek <dfsek@protonmail.com>
Date: Sat, 19 Jun 2021 20:15:59 -0700
Subject: [PATCH] Add more LimitedRegion API


diff --git a/src/main/java/io/papermc/paper/world/generation/CraftProtoWorld.java b/src/main/java/io/papermc/paper/world/generation/CraftProtoWorld.java
new file mode 100644
index 0000000000000000000000000000000000000000..3160766243e2ce90d07f71d02c7410ff4e9d9562
--- /dev/null
+++ b/src/main/java/io/papermc/paper/world/generation/CraftProtoWorld.java
@@ -0,0 +1,116 @@
+package io.papermc.paper.world.generation;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.WorldGenRegion;
+import net.minecraft.world.entity.Mob;
+import net.minecraft.world.entity.MobSpawnType;
+import net.minecraft.world.entity.SpawnGroupData;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import org.bukkit.World;
+import org.bukkit.block.BlockState;
+import org.bukkit.block.data.BlockData;
+import org.bukkit.craftbukkit.block.CraftBlockEntityState;
+import org.bukkit.craftbukkit.block.CraftBlockState;
+import org.bukkit.craftbukkit.block.data.CraftBlockData;
+import org.bukkit.craftbukkit.inventory.CraftMetaBlockState;
+import org.bukkit.entity.Entity;
+import org.bukkit.event.entity.CreatureSpawnEvent;
+import org.bukkit.util.Vector;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Objects;
+import java.util.function.Consumer;
+
+@Deprecated
+public class CraftProtoWorld implements ProtoWorld {
+    private WorldGenRegion region;
+
+    public CraftProtoWorld(WorldGenRegion region) {
+        this.region = region;
+    }
+
+    public void clearReference() {
+        region = null;
+    }
+
+    @Override
+    public void setBlockData(int x, int y, int z, @NotNull BlockData data) {
+        BlockPos position = new BlockPos(x, y, z);
+        getDelegate().setBlock(position, ((CraftBlockData) data).getState(), 3);
+    }
+
+    @Override
+    public void setBlockState(int x, int y, int z, @NotNull BlockState state) {
+        BlockPos pos = new BlockPos(x, y, z);
+        if(!state.getBlockData().matches(getDelegate().getBlockState(pos).createCraftBlockData())) {
+            throw new IllegalArgumentException("BlockData does not match! Expected " + state.getBlockData().getAsString(false) + ", got " + getDelegate().getBlockState(pos).createCraftBlockData().getAsString(false));
+        }
+        getDelegate().getBlockEntity(pos).load(((CraftBlockEntityState<?>) state).getSnapshotNBT());
+    }
+
+    @Override
+    public @NotNull BlockState getBlockState(int x, int y, int z) {
+        BlockEntity entity = getDelegate().getBlockEntity(new BlockPos(x, y, z));
+        return CraftMetaBlockState.createBlockState(entity.getBlockState().getBukkitMaterial(), entity.saveWithFullMetadata());
+    }
+
+    @Override
+    public void scheduleBlockUpdate(int x, int y, int z) {
+        BlockPos position = new BlockPos(x, y, z);
+        getDelegate().scheduleTick(position, getDelegate().getBlockIfLoaded(position), 0);
+    }
+
+    @Override
+    public void scheduleFluidUpdate(int x, int y, int z) {
+        BlockPos position = new BlockPos(x, y, z);
+        getDelegate().scheduleTick(position, getDelegate().getFluidState(position).getType(), 0);
+    }
+
+    @Override
+    public @NotNull World getWorld() {
+        // reading/writing the returned Minecraft world causes a deadlock.
+        // By implementing this, and covering it in warnings, we're assuming people won't be stupid, and
+        // if they are stupid, they'll figure it out pretty fast.
+        return getDelegate().getMinecraftWorld().getWorld();
+    }
+
+    @Override
+    public @NotNull BlockData getBlockData(int x, int y, int z) {
+        return CraftBlockData.fromData(getDelegate().getBlockState(new BlockPos(x, y, z)));
+    }
+
+    @Override
+    public int getCenterChunkX() {
+        return getDelegate().getCenter().x;
+    }
+
+    @Override
+    public int getCenterChunkZ() {
+        return getDelegate().getCenter().z;
+    }
+
+    @SuppressWarnings({"unchecked", "deprecation"})
+    @Override
+    public <T extends Entity> @NotNull T spawn(@NotNull Vector location, @NotNull Class<T> clazz, @Nullable Consumer<T> function, CreatureSpawnEvent.@NotNull SpawnReason reason) throws IllegalArgumentException {
+        net.minecraft.world.entity.Entity entity = getDelegate().getMinecraftWorld().getWorld().createEntity(location.toLocation(getWorld()), clazz);
+        Objects.requireNonNull(entity, "Cannot spawn null entity");
+        if (entity instanceof Mob mob) {
+            mob.finalizeSpawn(getDelegate(), getDelegate().getCurrentDifficultyAt(entity.blockPosition()), MobSpawnType.COMMAND, (SpawnGroupData) null, null);
+        }
+
+        if (function != null) {
+            function.accept((T) entity.getBukkitEntity());
+        }
+
+        getDelegate().addFreshEntity(entity, reason);
+        return (T) entity.getBukkitEntity();
+    }
+
+    @NotNull
+    private WorldGenRegion getDelegate() {
+        return Objects.requireNonNull(region, "Cannot access ProtoWorld after generation!");
+    }
+}
+
diff --git a/src/main/java/org/bukkit/craftbukkit/generator/CraftLimitedRegion.java b/src/main/java/org/bukkit/craftbukkit/generator/CraftLimitedRegion.java
index 94fee76f0b2145e3cf99460c407815bb32bd19d0..671ec060981790043f5685a5b647324ddfee6af2 100644
--- a/src/main/java/org/bukkit/craftbukkit/generator/CraftLimitedRegion.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/CraftLimitedRegion.java
@@ -151,7 +151,10 @@ public class CraftLimitedRegion extends CraftRegionAccessor implements LimitedRe
     @Override
     public BlockState getBlockState(int x, int y, int z) {
         Preconditions.checkArgument(this.isInRegion(x, y, z), "Coordinates %s, %s, %s are not in the region", x, y, z);
-        return super.getBlockState(x, y, z);
+        // Paper start
+        net.minecraft.world.level.block.entity.BlockEntity entity = getHandle().getBlockEntity(new BlockPos(x, y, z));
+        return org.bukkit.craftbukkit.inventory.CraftMetaBlockState.createBlockState(entity.getBlockState().getBukkitMaterial(), entity.saveWithFullMetadata());
+        // Paper end
     }
 
     @Override
@@ -169,7 +172,7 @@ public class CraftLimitedRegion extends CraftRegionAccessor implements LimitedRe
     @Override
     public void setBlockData(int x, int y, int z, BlockData blockData) {
         Preconditions.checkArgument(this.isInRegion(x, y, z), "Coordinates %s, %s, %s are not in the region", x, y, z);
-        super.setBlockData(x, y, z, blockData);
+        getHandle().setBlock(new BlockPos(x, y, z), ((org.bukkit.craftbukkit.block.data.CraftBlockData) blockData).getState(), 3); // Paper
     }
 
     @Override
@@ -199,4 +202,45 @@ public class CraftLimitedRegion extends CraftRegionAccessor implements LimitedRe
     public void addEntityToWorld(net.minecraft.world.entity.Entity entity, CreatureSpawnEvent.SpawnReason reason) {
         this.entities.add(entity);
     }
+
+    // Paper start
+    @Override
+    public void setBlockState(int x, int y, int z, BlockState state) {
+        BlockPos pos = new BlockPos(x, y, z);
+        if (!state.getBlockData().matches(getHandle().getBlockState(pos).createCraftBlockData())) {
+            throw new IllegalArgumentException("BlockData does not match! Expected " + state.getBlockData().getAsString(false) + ", got " + getHandle().getBlockState(pos).createCraftBlockData().getAsString(false));
+        }
+        getHandle().getBlockEntity(pos).load(((org.bukkit.craftbukkit.block.CraftBlockEntityState<?>) state).getSnapshotNBT());
+    }
+
+    @Override
+    public void scheduleBlockUpdate(int x, int y, int z) {
+        BlockPos position = new BlockPos(x, y, z);
+        getHandle().scheduleTick(position, getHandle().getBlockIfLoaded(position), 0);
+    }
+
+    @Override
+    public void scheduleFluidUpdate(int x, int y, int z) {
+        BlockPos position = new BlockPos(x, y, z);
+        getHandle().scheduleTick(position, getHandle().getFluidState(position).getType(), 0);
+    }
+
+    @Override
+    public World getWorld() {
+        // reading/writing the returned Minecraft world causes a deadlock.
+        // By implementing this, and covering it in warnings, we're assuming people won't be stupid, and
+        // if they are stupid, they'll figure it out pretty fast.
+        return getHandle().getMinecraftWorld().getWorld();
+    }
+
+    @Override
+    public int getCenterChunkX() {
+        return centerChunkX;
+    }
+
+    @Override
+    public int getCenterChunkZ() {
+        return centerChunkZ;
+    }
+    // Paper end
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java b/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
index c8e81b0a5495cd138a7b7a4aed98fd64beda59aa..cb49867045b1fdd9802ec815ab6bc17a6923c822 100644
--- a/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
@@ -205,6 +205,12 @@ public class CustomChunkGenerator extends InternalChunkGenerator {
         for (BlockPos lightPosition : craftData.getLights()) {
             ((ProtoChunk) chunk).addLight(new BlockPos((x << 4) + lightPosition.getX(), lightPosition.getY(), (z << 4) + lightPosition.getZ()));
         }
+
+        // Paper start
+        io.papermc.paper.world.generation.CraftProtoWorld protoWorld = new io.papermc.paper.world.generation.CraftProtoWorld(region);
+        generator.generateDecorations(protoWorld);
+        protoWorld.clearReference(); // make sure people dont try to use the ProtoWorld after we're done with it.
+        // Paper end
     }
 
     @Override
diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBlockState.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBlockState.java
index 55dd618d8421271063843c6e65dbcaceba9a33de..56f65b49e0ce55ee5aa9d929a98ea055ce27a8a1 100644
--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBlockState.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaBlockState.java
@@ -214,11 +214,16 @@ public class CraftMetaBlockState extends CraftMetaItem implements BlockStateMeta
 
     @Override
     public BlockState getBlockState() {
-        Material stateMaterial = (this.material != Material.SHIELD) ? this.material : CraftMetaBlockState.shieldToBannerHack(this.blockEntityTag); // Only actually used for jigsaws
-        if (this.blockEntityTag != null) {
-            switch (this.material) {
+        // Paper start
+        return createBlockState(this.material, this.blockEntityTag);
+    }
+    public static BlockState createBlockState(Material material, CompoundTag blockEntityTag) {
+        Material stateMaterial = (material != Material.SHIELD) ? material : CraftMetaBlockState.shieldToBannerHack(blockEntityTag); // Only actually used for jigsaws
+        if (blockEntityTag != null) {
+            switch (material) {
+                // Paper end
                 case SHIELD:
-                    this.blockEntityTag.putString("id", "banner");
+                    blockEntityTag.putString("id", "banner"); // Paper
                     break;
                 case SHULKER_BOX:
                 case WHITE_SHULKER_BOX:
@@ -237,11 +242,11 @@ public class CraftMetaBlockState extends CraftMetaItem implements BlockStateMeta
                 case GREEN_SHULKER_BOX:
                 case RED_SHULKER_BOX:
                 case BLACK_SHULKER_BOX:
-                    this.blockEntityTag.putString("id", "shulker_box");
+                    blockEntityTag.putString("id", "shulker_box"); // Paper
                     break;
                 case BEE_NEST:
                 case BEEHIVE:
-                    this.blockEntityTag.putString("id", "beehive");
+                    blockEntityTag.putString("id", "beehive"); // Paper
                     break;
             }
         }