Officially propagate GPL downwards to all files

(cherry picked from commit f2ce020da059718e34342c149172944dfd02b775)

HEADER.txt

@@ -2,15 +2,15 @@ WorldEdit, a Minecraft world manipulation toolkit
 Copyright (C) sk89q <http://www.sk89q.com>
 Copyright (C) WorldEdit team and contributors
 
-This program is free software: you can redistribute it and/or modify it
-under the terms of the GNU Lesser General Public License as published by the
-Free Software Foundation, either version 3 of the License, or
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 
-This program is distributed in the hope that it will be useful, but WITHOUT
-ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
-for more details.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
 
-You should have received a copy of the GNU Lesser General Public License
-along with this program. If not, see <http://www.gnu.org/licenses/>.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.

buildSrc/src/main/kotlin/CommonConfig.kt

@@ -19,6 +19,7 @@ fun Project.applyCommonConfiguration() {
                 artifact("/[organisation]/[revision]/artifact/[module].[ext]")
             }}
     }
+
     configurations.all {
         resolutionStrategy {
             cacheChangingModulesFor(5, "MINUTES")

worldedit-core/doctools/src/main/kotlin/com/sk89q/worldedit/internal/util/RstWorldEditText.kt

@@ -1,3 +1,22 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 package com.sk89q.worldedit.internal.util
 
 import com.sk89q.worldedit.util.formatting.WorldEditText

worldedit-core/src/main/java/com/sk89q/worldedit/EditSessionBuilder.java

@@ -0,0 +1,145 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit;
+
+import com.google.common.base.Preconditions;
+import com.sk89q.worldedit.extension.platform.Actor;
+import com.sk89q.worldedit.extension.platform.Locatable;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.extent.inventory.BlockBag;
+import com.sk89q.worldedit.util.eventbus.EventBus;
+import com.sk89q.worldedit.world.World;
+
+import javax.annotation.Nullable;
+
+/**
+ * A builder-style factory for {@link EditSession EditSessions}.
+ */
+public final class EditSessionBuilder {
+
+    private final EventBus eventBus;
+    private @Nullable World world;
+    private int maxBlocks = -1;
+    private @Nullable Actor actor;
+    private @Nullable BlockBag blockBag;
+    private boolean tracing;
+
+    EditSessionBuilder(EventBus eventBus) {
+        this.eventBus = eventBus;
+    }
+
+    public @Nullable World getWorld() {
+        return world;
+    }
+
+    /**
+     * Set the world for the {@link EditSession}.
+     *
+     * @param world the world
+     * @return this builder
+     */
+    public EditSessionBuilder world(@Nullable World world) {
+        this.world = world;
+        return this;
+    }
+
+    public int getMaxBlocks() {
+        return maxBlocks;
+    }
+
+    /**
+     * Set the maximum blocks to change for the {@link EditSession}.
+     *
+     * @param maxBlocks the maximum blocks to change
+     * @return this builder
+     */
+    public EditSessionBuilder maxBlocks(int maxBlocks) {
+        this.maxBlocks = maxBlocks;
+        return this;
+    }
+
+    public @Nullable Actor getActor() {
+        return actor;
+    }
+
+    /**
+     * Set the actor who owns the {@link EditSession}.
+     *
+     * @param actor the actor
+     * @return this builder
+     */
+    public EditSessionBuilder actor(@Nullable Actor actor) {
+        this.actor = actor;
+        return this;
+    }
+
+    public @Nullable BlockBag getBlockBag() {
+        return blockBag;
+    }
+
+    /**
+     * Set the block bag for the {@link EditSession}.
+     *
+     * @param blockBag the block bag
+     * @return this builder
+     */
+    public EditSessionBuilder blockBag(@Nullable BlockBag blockBag) {
+        this.blockBag = blockBag;
+        return this;
+    }
+
+    /**
+     * Check if tracing is enabled.
+     *
+     * <em>Internal use only.</em>
+     */
+    public boolean isTracing() {
+        return tracing;
+    }
+
+    /**
+     * Set tracing enabled/disabled.
+     *
+     * <em>Internal use only.</em>
+     */
+    public EditSessionBuilder tracing(boolean tracing) {
+        this.tracing = tracing;
+        return this;
+    }
+
+    // Extended methods
+    public <A extends Actor & Locatable> EditSessionBuilder locatableActor(A locatable) {
+        Extent extent = locatable.getExtent();
+        Preconditions.checkArgument(extent instanceof World, "%s is not located in a World", locatable);
+        return world(((World) extent)).actor(locatable);
+    }
+
+    /**
+     * Build the {@link EditSession} using properties described in this builder.
+     *
+     * @return the new EditSession
+     */
+    public EditSession build() {
+        if (WorldEdit.getInstance().getConfiguration().traceUnflushedSessions) {
+            return new TracedEditSession(eventBus, world, maxBlocks, blockBag, actor, tracing);
+        }
+        return new EditSession(eventBus, world, maxBlocks, blockBag, actor, tracing);
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/AbstractDirectionConverter.java

@@ -25,9 +25,9 @@ import com.google.common.collect.ImmutableSet;
 import com.sk89q.worldedit.UnknownDirectionException;
 import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.entity.Player;
-import com.sk89q.worldedit.extension.platform.Actor;
 import com.sk89q.worldedit.internal.annotation.Direction;
 import com.sk89q.worldedit.internal.annotation.MultiDirection;
+import com.sk89q.worldedit.internal.annotation.OptionalArg;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
 import org.enginehub.piston.CommandManager;
@@ -58,12 +58,12 @@ public abstract class AbstractDirectionConverter<D> implements ArgumentConverter
     protected static <D> void register(CommandManager commandManager, AbstractDirectionConverter<D> converter,
                                        Class<D> keyClass, boolean includeDiagonals) {
         commandManager.registerConverter(
-                Key.of(keyClass, direction(includeDiagonals)),
-                converter
+            Key.of(keyClass, direction(includeDiagonals)),
+            converter
         );
         commandManager.registerConverter(
-                Key.of(keyClass, multiDirection(includeDiagonals)),
-                CommaSeparatedValuesConverter.wrap(converter)
+            Key.of(keyClass, multiDirection(includeDiagonals)),
+            CommaSeparatedValuesConverter.wrap(converter)
         );
     }
 
@@ -93,8 +93,8 @@ public abstract class AbstractDirectionConverter<D> implements ArgumentConverter
 
     @Override
     public ConversionResult<D> convert(String argument, InjectedValueAccess context) {
-        Player player = context.injectedValue(Key.of(Actor.class))
-                .filter(Player.class::isInstance).map(Player.class::cast).orElse(null);
+        Player player = context.injectedValue(Key.of(Player.class, OptionalArg.class))
+            .orElse(null);
         try {
             return SuccessfulConversion.fromSingle(convertDirection(argument, player, includeDiagonals));
         } catch (Exception e) {

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/DirectionVectorConverter.java

@@ -29,7 +29,7 @@ import javax.annotation.Nullable;
 
 public final class DirectionVectorConverter extends AbstractDirectionConverter<BlockVector3> {
 
-    private DirectionVectorConverter(WorldEdit worldEdit, boolean includeDiagonals) {
+    public DirectionVectorConverter(WorldEdit worldEdit, boolean includeDiagonals) {
         super(worldEdit, includeDiagonals);
     }
 

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/OffsetConverter.java

@@ -0,0 +1,76 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.command.argument;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.internal.annotation.Offset;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.formatting.text.Component;
+import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import org.enginehub.piston.CommandManager;
+import org.enginehub.piston.converter.ArgumentConverter;
+import org.enginehub.piston.converter.ConversionResult;
+import org.enginehub.piston.inject.InjectedValueAccess;
+import org.enginehub.piston.inject.Key;
+
+import java.util.List;
+
+public class OffsetConverter implements ArgumentConverter<BlockVector3> {
+
+    public static void register(WorldEdit worldEdit, CommandManager commandManager) {
+        commandManager.registerConverter(
+            Key.of(BlockVector3.class, Offset.class),
+            new OffsetConverter(worldEdit)
+        );
+    }
+
+    private final DirectionVectorConverter directionVectorConverter;
+    private final VectorConverter<Integer, BlockVector3> vectorConverter =
+        VectorConverter.BLOCK_VECTOR_3_CONVERTER;
+
+    private OffsetConverter(WorldEdit worldEdit) {
+        directionVectorConverter = new DirectionVectorConverter(worldEdit, true);
+    }
+
+    @Override
+    public Component describeAcceptableArguments() {
+        return TextComponent.builder()
+            .append(directionVectorConverter.describeAcceptableArguments())
+            .append(", or ")
+            .append(vectorConverter.describeAcceptableArguments())
+            .build();
+    }
+
+    @Override
+    public List<String> getSuggestions(String input, InjectedValueAccess context) {
+        return ImmutableList.copyOf(Iterables.concat(
+            directionVectorConverter.getSuggestions(input, context),
+            vectorConverter.getSuggestions(input, context)
+        ));
+    }
+
+    @Override
+    public ConversionResult<BlockVector3> convert(String input, InjectedValueAccess context) {
+        return directionVectorConverter.convert(input, context)
+            .orElse(vectorConverter.convert(input, context));
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/VectorConverter.java

@@ -40,12 +40,22 @@ import java.util.List;
 import java.util.function.Function;
 
 public class VectorConverter<C, T> implements ArgumentConverter<T> {
+
+    private static final CommaSeparatedValuesConverter<Integer> INT_CONVERTER =
+        CommaSeparatedValuesConverter.wrap(ArgumentConverters.get(TypeToken.of(int.class)));
+
+    public static final VectorConverter<Integer, BlockVector3> BLOCK_VECTOR_3_CONVERTER = new VectorConverter<>(
+        INT_CONVERTER,
+        3,
+        cmps -> BlockVector3.at(cmps.get(0), cmps.get(1), cmps.get(2)),
+        "block vector with x, y, and z"
+    );
+
     public static void register(CommandManager commandManager) {
-        CommaSeparatedValuesConverter<Integer> intConverter = CommaSeparatedValuesConverter.wrap(ArgumentConverters.get(TypeToken.of(int.class)));
         CommaSeparatedValuesConverter<Double> doubleConverter = CommaSeparatedValuesConverter.wrap(ArgumentConverters.get(TypeToken.of(double.class)));
         commandManager.registerConverter(Key.of(BlockVector2.class),
             new VectorConverter<>(
-                intConverter,
+                INT_CONVERTER,
                 2,
                 cmps -> BlockVector2.at(cmps.get(0), cmps.get(1)),
                 "block vector with x and z"
@@ -57,13 +67,7 @@ public class VectorConverter<C, T> implements ArgumentConverter<T> {
                 cmps -> Vector2.at(cmps.get(0), cmps.get(1)),
                 "vector with x and z"
             ));
-        commandManager.registerConverter(Key.of(BlockVector3.class),
-            new VectorConverter<>(
-                intConverter,
-                3,
-                cmps -> BlockVector3.at(cmps.get(0), cmps.get(1), cmps.get(2)),
-                "block vector with x, y, and z"
-            ));
+        commandManager.registerConverter(Key.of(BlockVector3.class), BLOCK_VECTOR_3_CONVERTER);
         commandManager.registerConverter(Key.of(Vector3.class),
             new VectorConverter<>(
                 doubleConverter,

worldedit-core/src/main/java/com/sk89q/worldedit/command/tool/StackTool.java

@@ -0,0 +1,85 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.command.tool;
+
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.LocalConfiguration;
+import com.sk89q.worldedit.LocalSession;
+import com.sk89q.worldedit.MaxChangedBlocksException;
+import com.sk89q.worldedit.entity.Player;
+import com.sk89q.worldedit.extension.platform.Actor;
+import com.sk89q.worldedit.extension.platform.Platform;
+import com.sk89q.worldedit.extent.inventory.BlockBag;
+import com.sk89q.worldedit.function.mask.Mask;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.Location;
+import com.sk89q.worldedit.world.block.BlockStateHolder;
+
+import javax.annotation.Nullable;
+
+public class StackTool implements BlockTool {
+
+    private final int range;
+    private final Mask mask;
+
+    public StackTool(int range, Mask mask) {
+        this.range = range;
+        this.mask = mask;
+    }
+
+    @Override
+    public boolean actPrimary(Platform server, LocalConfiguration config, Player player, LocalSession session, Location clicked, @Nullable Direction face) {
+        if (face == null) {
+            return false;
+        }
+        BlockBag bag = session.getBlockBag(player);
+
+        try (EditSession editSession = session.createEditSession(player)) {
+            BlockStateHolder<?> block = editSession.getFullBlock(clicked.toVector().toBlockPoint());
+
+            try {
+                editSession.disableBuffering();
+                BlockVector3 position = clicked.toVector().toBlockPoint();
+                for (int i = 0; i < range; i++) {
+                    position = position.add(face.toBlockVector());
+                    if (!mask.test(position)) {
+                        break;
+                    }
+                    editSession.setBlock(position, block);
+                }
+            } catch (MaxChangedBlocksException ignored) {
+            } finally {
+                session.remember(editSession);
+            }
+        } finally {
+            if (bag != null) {
+                bag.flushChanges();
+            }
+        }
+
+        return true;
+    }
+
+    @Override
+    public boolean canUse(Actor actor) {
+        return actor.hasPermission("worldedit.tool.stack");
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/extent/TracingExtent.java

@@ -0,0 +1,113 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.extent;
+
+import com.google.common.collect.Multimaps;
+import com.google.common.collect.SetMultimap;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.entity.BaseEntity;
+import com.sk89q.worldedit.entity.Entity;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.Location;
+import com.sk89q.worldedit.util.collection.BlockMap;
+import com.sk89q.worldedit.world.biome.BiomeType;
+import com.sk89q.worldedit.world.block.BlockStateHolder;
+
+import java.util.Collections;
+import java.util.EnumSet;
+import java.util.Set;
+import javax.annotation.Nullable;
+
+/**
+ * An extent that can report back if an operation fails due to the extent(s) below it.
+ *
+ * <em>Internal use only.</em>
+ */
+public class TracingExtent extends AbstractDelegateExtent {
+
+    public enum Action {
+        SET_BLOCK,
+        SET_BIOME,
+        CREATE_ENTITY,
+    }
+
+    private final Set<BlockVector3> touchedLocations = Collections.newSetFromMap(BlockMap.create());
+    private final SetMultimap<BlockVector3, Action> failedActions = Multimaps.newSetMultimap(
+            BlockMap.create(), () -> EnumSet.noneOf(Action.class)
+    );
+
+    /**
+     * Create a new instance.
+     *
+     * @param extent the extent
+     */
+    public TracingExtent(Extent extent) {
+        super(extent);
+    }
+
+    public boolean isActive() {
+        return !touchedLocations.isEmpty();
+    }
+
+    public Set<BlockVector3> getTouchedLocations() {
+        return Collections.unmodifiableSet(touchedLocations);
+    }
+
+    public SetMultimap<BlockVector3, Action> getFailedActions() {
+        return Multimaps.unmodifiableSetMultimap(failedActions);
+    }
+
+    @Override
+    public <T extends BlockStateHolder<T>> boolean setBlock(BlockVector3 location, T block) throws WorldEditException {
+        touchedLocations.add(location);
+        boolean result = super.setBlock(location, block);
+        if (!result) {
+            failedActions.put(location, Action.SET_BLOCK);
+        }
+        return result;
+    }
+
+    @Override
+    public boolean setBiome(BlockVector3 position, BiomeType biome) {
+        touchedLocations.add(position);
+        boolean result = super.setBiome(position, biome);
+        if (!result) {
+            failedActions.put(position, Action.SET_BIOME);
+        }
+        return result;
+    }
+
+    @Nullable
+    @Override
+    public Entity createEntity(Location location, BaseEntity entity) {
+        BlockVector3 blockVector3 = location.toVector().toBlockPoint();
+        touchedLocations.add(blockVector3);
+        Entity result = super.createEntity(location, entity);
+        if (result == null) {
+            failedActions.put(blockVector3, Action.CREATE_ENTITY);
+        }
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "TracingExtent{delegate=" + getExtent() + "}";
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/extent/world/BiomeQuirkExtent.java

@@ -0,0 +1,50 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.extent.world;
+
+import com.sk89q.worldedit.extent.AbstractDelegateExtent;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.world.biome.BiomeType;
+
+/**
+ * Handles quirks when placing biomes.
+ */
+public class BiomeQuirkExtent extends AbstractDelegateExtent {
+
+    /**
+     * Create a new instance.
+     *
+     * @param extent the extent
+     */
+    public BiomeQuirkExtent(Extent extent) {
+        super(extent);
+    }
+
+    @Override
+    public boolean setBiome(BlockVector3 position, BiomeType biome) {
+        boolean success = false;
+        if (!fullySupports3DBiomes()) {
+            // Also place at Y = 0 for proper handling
+            success = super.setBiome(position.withY(0), biome);
+        }
+        return super.setBiome(position, biome) || success;
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/block/SnowSimulator.java

@@ -0,0 +1,124 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.function.block;
+
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.function.LayerFunction;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.registry.state.Property;
+import com.sk89q.worldedit.world.block.BlockState;
+import com.sk89q.worldedit.world.block.BlockTypes;
+
+public class SnowSimulator implements LayerFunction {
+
+    private final BlockState ice = BlockTypes.ICE.getDefaultState();
+    private final BlockState snow = BlockTypes.SNOW.getDefaultState();
+    private final BlockState snowBlock = BlockTypes.SNOW_BLOCK.getDefaultState();
+
+    private final Property<Integer> snowLayersProperty = BlockTypes.SNOW.getProperty("layers");
+    private final Property<Integer> waterLevelProperty = BlockTypes.WATER.getProperty("level");
+
+    private final Extent extent;
+    private final boolean stack;
+
+    private int affected;
+
+    public SnowSimulator(Extent extent, boolean stack) {
+        this.extent = extent;
+        this.stack = stack;
+
+        this.affected = 0;
+    }
+
+    public int getAffected() {
+        return this.affected;
+    }
+
+    @Override
+    public boolean isGround(BlockVector3 position) {
+        BlockState block = this.extent.getBlock(position);
+
+        // We're returning the first block we can place *on top of*
+        if (block.getBlockType().getMaterial().isAir() || (stack && block.getBlockType() == BlockTypes.SNOW)) {
+            return false;
+        }
+
+        // Unless it's water
+        if (block.getBlockType() == BlockTypes.WATER) {
+            return true;
+        }
+
+        // Can only place on full solid blocks
+        return block.getBlockType().getMaterial().isFullCube()
+                && block.getBlockType().getMaterial().isSolid();
+    }
+
+    @Override
+    public boolean apply(BlockVector3 position, int depth) throws WorldEditException {
+        if (depth > 0) {
+            // We only care about the first layer.
+            return false;
+        }
+
+        BlockState block = this.extent.getBlock(position);
+
+        if (block.getBlockType() == BlockTypes.WATER) {
+            if (block.getState(waterLevelProperty) == 0) {
+                if (this.extent.setBlock(position, ice)) {
+                    affected++;
+                }
+            }
+            return false;
+        }
+
+        // Can't put snow this far up
+        if (position.getBlockY() == this.extent.getMaximumPoint().getBlockY()) {
+            return false;
+        }
+
+        BlockVector3 abovePosition = position.add(0, 1, 0);
+        BlockState above = this.extent.getBlock(abovePosition);
+
+        // Can only replace air (or snow in stack mode)
+        if (!above.getBlockType().getMaterial().isAir() && (!stack || above.getBlockType() != BlockTypes.SNOW)) {
+            return false;
+        }
+
+        if (stack && above.getBlockType() == BlockTypes.SNOW) {
+            int currentHeight = above.getState(snowLayersProperty);
+            // We've hit the highest layer (If it doesn't contain current + 2 it means it's 1 away from full)
+            if (!snowLayersProperty.getValues().contains(currentHeight + 2)) {
+                if (this.extent.setBlock(abovePosition, snowBlock)) {
+                    this.affected++;
+                }
+            } else {
+                if (this.extent.setBlock(abovePosition, above.with(snowLayersProperty, currentHeight + 1))) {
+                    this.affected++;
+                }
+            }
+            return false;
+        }
+        if (this.extent.setBlock(abovePosition, snow)) {
+            this.affected++;
+        }
+        return false;
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/ApplyLayer.java

@@ -0,0 +1,65 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.sk89q.worldedit.function.Contextual;
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.LayerFunction;
+import com.sk89q.worldedit.function.operation.Operation;
+import com.sk89q.worldedit.function.visitor.LayerVisitor;
+import com.sk89q.worldedit.regions.FlatRegion;
+import com.sk89q.worldedit.regions.NullRegion;
+import com.sk89q.worldedit.regions.Regions;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.sk89q.worldedit.util.GuavaUtil.firstNonNull;
+
+public class ApplyLayer implements Contextual<Operation> {
+
+    private final FlatRegion region;
+    private final Contextual<? extends LayerFunction> function;
+
+    public ApplyLayer(Contextual<? extends LayerFunction> function) {
+        this(Regions.asFlatRegion(new NullRegion()), function);
+    }
+
+    public ApplyLayer(FlatRegion region, Contextual<? extends LayerFunction> function) {
+        checkNotNull(region, "region");
+        checkNotNull(function, "function");
+        this.region = region;
+        this.function = function;
+    }
+
+    @Override
+    public Operation createFromContext(EditContext context) {
+        FlatRegion localRegion = Regions.asFlatRegion(firstNonNull(context.getRegion(), region));
+
+        return new LayerVisitor(localRegion,
+            localRegion.getMinimumPoint().getY(),
+            localRegion.getMaximumPoint().getY(),
+            function.createFromContext(context));
+    }
+
+    @Override
+    public String toString() {
+        return "set " + function;
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/ApplyRegion.java

@@ -0,0 +1,59 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.sk89q.worldedit.function.Contextual;
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.RegionFunction;
+import com.sk89q.worldedit.function.operation.Operation;
+import com.sk89q.worldedit.function.visitor.RegionVisitor;
+import com.sk89q.worldedit.regions.NullRegion;
+import com.sk89q.worldedit.regions.Region;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.sk89q.worldedit.util.GuavaUtil.firstNonNull;
+
+public class ApplyRegion implements Contextual<Operation> {
+
+    private final Region region;
+    private final Contextual<? extends RegionFunction> function;
+
+    public ApplyRegion(Contextual<? extends RegionFunction> function) {
+        this(new NullRegion(), function);
+    }
+
+    public ApplyRegion(Region region, Contextual<? extends RegionFunction> function) {
+        checkNotNull(region, "region");
+        checkNotNull(function, "function");
+        this.region = region;
+        this.function = function;
+    }
+
+    @Override
+    public Operation createFromContext(EditContext context) {
+        return new RegionVisitor(firstNonNull(context.getRegion(), region), function.createFromContext(context));
+    }
+
+    @Override
+    public String toString() {
+        return "set " + function;
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/function/factory/Snow.java

@@ -0,0 +1,44 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.function.factory;
+
+import com.sk89q.worldedit.function.Contextual;
+import com.sk89q.worldedit.function.EditContext;
+import com.sk89q.worldedit.function.LayerFunction;
+import com.sk89q.worldedit.function.block.SnowSimulator;
+
+public class Snow implements Contextual<LayerFunction> {
+
+    private final boolean stack;
+
+    public Snow(boolean stack) {
+        this.stack = stack;
+    }
+
+    @Override
+    public LayerFunction createFromContext(EditContext context) {
+        return new SnowSimulator(context.getDestination(), this.stack);
+    }
+
+    @Override
+    public String toString() {
+        return "snow" + (this.stack ? " stacker" : "");
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/history/change/BiomeChange3D.java

@@ -0,0 +1,96 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.history.change;
+
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.history.UndoContext;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.world.biome.BiomeType;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Represents a biome change that may be undone or replayed.
+ *
+ * <p>This biome change does not have an {@link Extent} assigned to it because
+ * one will be taken from the passed {@link UndoContext}. If the context
+ * does not have an extent (it is null), cryptic errors may occur.</p>
+ */
+public class BiomeChange3D implements Change {
+
+    private final BlockVector3 position;
+    private final BiomeType previous;
+    private final BiomeType current;
+
+    /**
+     * Create a new biome change.
+     *
+     * @param position the position
+     * @param previous the previous biome
+     * @param current the current biome
+     */
+    public BiomeChange3D(BlockVector3 position, BiomeType previous, BiomeType current) {
+        checkNotNull(position);
+        checkNotNull(previous);
+        checkNotNull(current);
+        this.position = position;
+        this.previous = previous;
+        this.current = current;
+    }
+
+    /**
+     * Get the position.
+     *
+     * @return the position
+     */
+    public BlockVector3 getPosition() {
+        return position;
+    }
+
+    /**
+     * Get the previous biome.
+     *
+     * @return the previous biome
+     */
+    public BiomeType getPrevious() {
+        return previous;
+    }
+
+    /**
+     * Get the current biome.
+     *
+     * @return the current biome
+     */
+    public BiomeType getCurrent() {
+        return current;
+    }
+
+    @Override
+    public void undo(UndoContext context) throws WorldEditException {
+        checkNotNull(context.getExtent()).setBiome(position, previous);
+    }
+
+    @Override
+    public void redo(UndoContext context) throws WorldEditException {
+        checkNotNull(context.getExtent()).setBiome(position, current);
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/internal/annotation/Offset.java

@@ -0,0 +1,38 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.internal.annotation;
+
+import com.sk89q.worldedit.math.BlockVector3;
+import org.enginehub.piston.inject.InjectAnnotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Annotates a {@link BlockVector3} parameter to inject an offset.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.PARAMETER)
+@InjectAnnotation
+public @interface Offset {
+    String FORWARD = "forward";
+}

worldedit-core/src/main/java/com/sk89q/worldedit/internal/annotation/OptionalArg.java

@@ -0,0 +1,38 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.internal.annotation;
+
+import com.sk89q.worldedit.entity.Player;
+import org.enginehub.piston.inject.InjectAnnotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Annotates a parameter to indicate it as optional. This is really a bit of a hack, used to
+ * get a {@link Player} or {@code null} instead of throwing.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.PARAMETER)
+@InjectAnnotation
+public @interface OptionalArg {
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/RegenOptions.java

@@ -0,0 +1,102 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world;
+
+import com.google.auto.value.AutoValue;
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.regions.Region;
+
+import java.util.OptionalLong;
+import javax.annotation.Nullable;
+
+/**
+ * Regeneration options for {@link World#regenerate(Region, EditSession, RegenOptions)}.
+ */
+@AutoValue
+public abstract class RegenOptions {
+
+    /**
+     * Creates a new options builder.
+     *
+     * @return the builder
+     */
+    public static Builder builder() {
+        return new AutoValue_RegenOptions.Builder().seed(OptionalLong.empty()).regenBiomes(false);
+    }
+
+    @AutoValue.Builder
+    public abstract static class Builder {
+
+        /**
+         * Sets the seed to regenerate with. Defaults to {@code null}.
+         *
+         * <p>
+         * Use {@code null} to use the world's current seed.
+         * </p>
+         *
+         * @param seed the seed to regenerate with
+         * @return this builder
+         */
+        public final Builder seed(@Nullable Long seed) {
+            return seed(seed == null ? OptionalLong.empty() : OptionalLong.of(seed));
+        }
+
+        // AV doesn't like us using @Nullable Long for some reason
+        abstract Builder seed(OptionalLong seed);
+
+        /**
+         * Turn on or off applying the biomes from the regenerated chunk. Defaults to {@code false}.
+         *
+         * @param regenBiomes {@code true} to apply biomes
+         * @return this builder
+         */
+        public abstract Builder regenBiomes(boolean regenBiomes);
+
+        /**
+         * Build the options object.
+         *
+         * @return the options object
+         */
+        public abstract RegenOptions build();
+
+    }
+
+    RegenOptions() {
+    }
+
+    /**
+     * The seed to regenerate with.
+     *
+     * <p>
+     * {@link OptionalLong#empty()} if the world's original seed should be used.
+     * </p>
+     */
+    public abstract OptionalLong getSeed();
+
+    abstract boolean isRegenBiomes();
+
+    /**
+     * Whether biomes should be regenerated.
+     */
+    public final boolean shouldRegenBiomes() {
+        return isRegenBiomes();
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/WorldUnloadedException.java

@@ -0,0 +1,36 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world;
+
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
+
+/**
+ * Thrown if the world has been unloaded.
+ */
+public class WorldUnloadedException extends WorldEditException {
+
+    /**
+     * Create a new instance.
+     */
+    public WorldUnloadedException() {
+        super(TranslatableComponent.of("worldedit.error.world-unloaded"));
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/chunk/AnvilChunk16.java

@@ -0,0 +1,53 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.chunk;
+
+import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.worldedit.world.DataException;
+import com.sk89q.worldedit.world.block.BlockState;
+import com.sk89q.worldedit.world.storage.InvalidFormatException;
+
+/**
+ * The chunk format for Minecraft 1.16 and newer
+ */
+public class AnvilChunk16 extends AnvilChunk13 {
+
+    /**
+     * Construct the chunk with a compound tag.
+     *
+     * @param tag the tag to read
+     * @throws DataException on a data error
+     */
+    public AnvilChunk16(CompoundTag tag) throws DataException {
+        super(tag);
+    }
+
+    @Override
+    protected void readBlockStates(BlockState[] palette, long[] blockStatesSerialized, BlockState[] chunkSectionBlocks) throws InvalidFormatException {
+        PackedIntArrayReader reader = new PackedIntArrayReader(blockStatesSerialized);
+        for (int blockPos = 0; blockPos < chunkSectionBlocks.length; blockPos++) {
+            int index = reader.get(blockPos);
+            if (index >= palette.length) {
+                throw new InvalidFormatException("Invalid block state table entry: " + index);
+            }
+            chunkSectionBlocks[blockPos] = palette[index];
+        }
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/chunk/PackedIntArrayReader.java

@@ -0,0 +1,66 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.chunk;
+
+import static com.google.common.base.Preconditions.checkElementIndex;
+
+public class PackedIntArrayReader {
+    private static final int[] FACTORS = new int[64];
+
+    static {
+        FACTORS[0] = -1;
+        for (int i = 2; i <= 64; i++) {
+            FACTORS[i - 1] = (int) (Integer.toUnsignedLong(-1) / i);
+        }
+    }
+
+    private static final int SIZE = 4096;
+
+    private final long[] data;
+    private final int elementBits;
+    private final long maxValue;
+    private final int elementsPerLong;
+    private final int factor;
+
+    public PackedIntArrayReader(long[] data) {
+        this.data = data;
+        this.elementBits = data.length * 64 / 4096;
+        this.maxValue = (1L << elementBits) - 1L;
+        this.elementsPerLong = 64 / elementBits;
+        this.factor = FACTORS[elementsPerLong - 1];
+        int j = (SIZE + this.elementsPerLong - 1) / this.elementsPerLong;
+        if (j != data.length) {
+            throw new IllegalStateException("Invalid packed-int array provided, should be of length " + j);
+        }
+    }
+
+    public int get(int index) {
+        checkElementIndex(index, SIZE);
+        int i = this.adjustIndex(index);
+        long l = this.data[i];
+        int j = (index - i * this.elementsPerLong) * this.elementBits;
+        return (int) (l >> j & this.maxValue);
+    }
+
+    private int adjustIndex(int i) {
+        return (int) ((long) i * factor + factor >> 32);
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/item/ItemTypes.java

@@ -3,18 +3,18 @@
  * Copyright (C) sk89q <http://www.sk89q.com>
  * Copyright (C) WorldEdit team and contributors
  *
- * This program is free software: you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License as published by the
- * Free Software Foundation, either version 3 of the License, or
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
  *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
- * for more details.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
 package com.sk89q.worldedit.world.item;

worldedit-core/src/test/java/com/sk89q/worldedit/internal/util/DeprecationUtilTest.java

@@ -0,0 +1,88 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.internal.util;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class DeprecationUtilTest {
+
+    public interface ModifiedApi {
+        @Deprecated
+        default boolean oldApi() {
+            return newApi();
+        }
+
+        @NonAbstractForCompatibility(
+            delegateName = "oldApi",
+            delegateParams = {}
+        )
+        default boolean newApi() {
+            DeprecationUtil.checkDelegatingOverride(getClass());
+            return oldApi();
+        }
+    }
+
+    public static class OldImpl implements ModifiedApi {
+        @SuppressWarnings("deprecation")
+        @Override
+        public boolean oldApi() {
+            return false;
+        }
+    }
+
+    public static class NewImpl implements ModifiedApi {
+        @Override
+        public boolean newApi() {
+            return true;
+        }
+    }
+
+    public static class NewBadImpl implements ModifiedApi {
+    }
+
+    @Test
+    void oldImpl() {
+        assertFalse(new OldImpl().oldApi());
+        assertFalse(new OldImpl().newApi());
+    }
+
+    @Test
+    void newImpl() {
+        assertTrue(new NewImpl().oldApi());
+        assertTrue(new NewImpl().newApi());
+    }
+
+    @Test
+    void newBadImpl() {
+        // regardless of which method is called, the message is the same
+        Exception ex = assertThrows(IllegalStateException.class, new NewBadImpl()::oldApi);
+        assertTrue(ex.getMessage().contains("must override"));
+        assertTrue(ex.getMessage().contains("ModifiedApi.newApi()"));
+
+        ex = assertThrows(IllegalStateException.class, new NewBadImpl()::newApi);
+        assertTrue(ex.getMessage().contains("must override"));
+        assertTrue(ex.getMessage().contains("ModifiedApi.newApi()"));
+    }
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/MutableBiomeArray.java

@@ -0,0 +1,42 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric;
+
+import net.minecraft.world.biome.Biome;
+import net.minecraft.world.biome.source.BiomeArray;
+
+/**
+ * Interface over a {@link BiomeArray} as a mutable object.
+ */
+public interface MutableBiomeArray {
+
+    /**
+     * Hook into the given biome array, to allow edits on it.
+     * @param biomeArray the biome array to edit
+     * @return the mutable interface to the biome array
+     */
+    static MutableBiomeArray inject(BiomeArray biomeArray) {
+        // It's Mixin'd
+        return (MutableBiomeArray) biomeArray;
+    }
+
+    void setBiome(int x, int y, int z, Biome biome);
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/WorldEditGenListener.java

@@ -0,0 +1,43 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric;
+
+import net.minecraft.server.WorldGenerationProgressListener;
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.world.chunk.ChunkStatus;
+
+import javax.annotation.Nullable;
+
+// For now, this does nothing, but might be useful later for regen progress communication.
+class WorldEditGenListener implements WorldGenerationProgressListener {
+
+    @Override
+    public void start(ChunkPos spawnPos) {
+    }
+
+    @Override
+    public void setChunkStatus(ChunkPos pos, @Nullable ChunkStatus status) {
+    }
+
+    @Override
+    public void stop() {
+    }
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/internal/ExtendedMinecraftServer.java

@@ -0,0 +1,33 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.internal;
+
+import net.minecraft.resource.ServerResourceManager;
+import net.minecraft.world.World;
+
+import java.nio.file.Path;
+
+public interface ExtendedMinecraftServer {
+
+    Path getStoragePath(World world);
+
+    ServerResourceManager getServerResourceManager();
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/internal/ExtendedPlayerEntity.java

@@ -0,0 +1,26 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.internal;
+
+public interface ExtendedPlayerEntity {
+
+    String getLanguage();
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/mixin/AccessorClientSettingsC2SPacket.java

@@ -0,0 +1,32 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.mixin;
+
+import net.minecraft.network.packet.c2s.play.ClientSettingsC2SPacket;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+@Mixin(ClientSettingsC2SPacket.class)
+public interface AccessorClientSettingsC2SPacket {
+
+    @Accessor
+    String getLanguage();
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/mixin/AccessorLevelProperties.java

@@ -0,0 +1,36 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.mixin;
+
+import net.minecraft.world.SaveProperties;
+import net.minecraft.world.gen.GeneratorOptions;
+import net.minecraft.world.level.LevelProperties;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+@Mixin(LevelProperties.class)
+public interface AccessorLevelProperties extends SaveProperties {
+
+    @Accessor
+    @Mutable
+    void setGeneratorOptions(GeneratorOptions options);
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/mixin/AccessorServerChunkManager.java

@@ -0,0 +1,42 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.mixin;
+
+import com.mojang.datafixers.util.Either;
+import net.minecraft.server.world.ChunkHolder;
+import net.minecraft.server.world.ServerChunkManager;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.chunk.ChunkStatus;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+import org.spongepowered.asm.mixin.gen.Invoker;
+
+import java.util.concurrent.CompletableFuture;
+
+@Mixin(ServerChunkManager.class)
+public interface AccessorServerChunkManager {
+
+    @Invoker
+    CompletableFuture<Either<Chunk, ChunkHolder.Unloaded>> callGetChunkFuture(int chunkX, int chunkZ, ChunkStatus leastStatus, boolean create);
+
+    @Accessor
+    ServerChunkManager.MainThreadExecutor getMainThreadExecutor();
+
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/mixin/MixinBiomeArray.java

@@ -0,0 +1,39 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.mixin;
+
+import com.sk89q.worldedit.fabric.MutableBiomeArray;
+import com.sk89q.worldedit.internal.util.BiomeMath;
+import net.minecraft.world.biome.Biome;
+import net.minecraft.world.biome.source.BiomeArray;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(BiomeArray.class)
+public abstract class MixinBiomeArray implements MutableBiomeArray {
+
+    @Shadow
+    private Biome[] data;
+
+    @Override
+    public void setBiome(int x, int y, int z, Biome biome) {
+        this.data[BiomeMath.computeBiomeIndex(x, y, z)] = biome;
+    }
+}

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeResourceLoader.java

@@ -0,0 +1,51 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.forge;
+
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.util.io.WorldEditResourceLoader;
+
+import java.io.IOException;
+import java.net.URL;
+
+public class ForgeResourceLoader extends WorldEditResourceLoader  {
+
+    public ForgeResourceLoader(WorldEdit worldEdit) {
+        super(worldEdit);
+    }
+
+    private static URL getResourceForgeHack(String location) throws IOException {
+        try {
+            return new URL("modjar://worldedit/" + location);
+        } catch (Exception e) {
+            throw new IOException("Could not find " + location);
+        }
+    }
+
+    @Override
+    public URL getRootResource(String pathName) throws IOException {
+        URL url = super.getRootResource(pathName);
+        if (url == null) {
+            return getResourceForgeHack(pathName);
+        }
+        return url;
+    }
+
+}

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/WorldEditGenListener.java

@@ -0,0 +1,44 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.forge;
+
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.world.chunk.ChunkStatus;
+import net.minecraft.world.chunk.listener.IChunkStatusListener;
+
+import javax.annotation.Nullable;
+
+// For now, this does nothing, but might be useful later for regen progress communication.
+class WorldEditGenListener implements IChunkStatusListener {
+
+    @Override
+    public void start(ChunkPos spawnPos) {
+    }
+
+    @Override
+    public void statusChanged(ChunkPos chunkPosition, @Nullable ChunkStatus newStatus) {
+
+    }
+
+    @Override
+    public void stop() {
+    }
+
+}