Began work on integrating the new Contexts. Compiles but does not work

- All TickContexts including TickContextMutable are deleted
- Previous occurrences of TickContexts are replaced by appropriate
ServerContexts
- Added Context.popAndReturn methods for convenience

Current known problems:
- World does not generate properly on startup
- No bulk methods in the new API (the likes of forEachTile, etc.)
- AbsFace/RelFace ambiguity in the new API (see
TestTileLogicGrass.java:68)
- TestTileLogicGrass.java:53 is disabled for some reason

src/main/java/ru/windcorp/progressia/common/world/context/Context.java

@@ -136,4 +136,24 @@ public interface Context {
 	 */
 	void pop();
 	
+	default <T> T popAndReturn(T result) {
+		pop();
+		return result;
+	}
+	
+	default boolean popAndReturn(boolean result) {
+		pop();
+		return result;
+	}
+	
+	default int popAndReturn(int result) {
+		pop();
+		return result;
+	}
+	
+	default float popAndReturn(float result) {
+		pop();
+		return result;
+	}
+
 }

src/main/java/ru/windcorp/progressia/server/Server.java

@@ -35,6 +35,9 @@ import ru.windcorp.progressia.server.management.load.ChunkRequestDaemon;
 import ru.windcorp.progressia.server.management.load.EntityRequestDaemon;
 import ru.windcorp.progressia.server.management.load.LoadManager;
 import ru.windcorp.progressia.server.world.DefaultWorldLogic;
+import ru.windcorp.progressia.server.world.context.ServerWorldContext;
+import ru.windcorp.progressia.server.world.context.impl.DefaultServerContext;
+import ru.windcorp.progressia.server.world.context.impl.ReportingServerContext;
 import ru.windcorp.progressia.server.world.tasks.WorldAccessor;
 import ru.windcorp.progressia.server.world.ticking.Change;
 import ru.windcorp.progressia.server.world.ticking.Evaluation;
@@ -97,6 +100,19 @@ public class Server {
 		return world;
 	}
 
+	/**
+	 * Instantiates and returns an new {@link ServerWorldContext} instance
+	 * suitable for read and write access to the server's world. This is the
+	 * preferred way to query or change the world.
+	 * 
+	 * @return the context
+	 */
+	public ServerWorldContext createContext() {
+
+		return new ReportingServerContext(DefaultServerContext.empty().inRealWorldOf(this).build()).withListener(worldAccessor);
+		
+	}
+
 	/**
 	 * Returns this server's {@link ClientManager}. Use this to deal with
 	 * communications, e.g. send packets.
@@ -219,16 +235,20 @@ public class Server {
 		return this.serverThread.getTicker().getUptimeTicks();
 	}
 
-	/**
+//	/**
-	 * Returns the {@link WorldAccessor} object for this server. Use the
+//	 * Returns the {@link WorldAccessor} object for this server. Use the
-	 * provided accessor to request common {@link Evaluation}s and
+//	 * provided accessor to request common {@link Evaluation}s and
-	 * {@link Change}s.
+//	 * {@link Change}s.
-	 * 
+//	 * 
-	 * @return a {@link WorldAccessor}
+//	 * @return a {@link WorldAccessor}
-	 * @see #requestChange(Change)
+//	 * @see #requestChange(Change)
-	 * @see #requestEvaluation(Evaluation)
+//	 * @see #requestEvaluation(Evaluation)
-	 */
+//	 */
-	public WorldAccessor getWorldAccessor() {
+//	public WorldAccessor getWorldAccessor() {
+//		return worldAccessor;
+//	}
+	
+	public WorldAccessor getWorldAccessor___really_bad_dont_use() {
 		return worldAccessor;
 	}
 

src/main/java/ru/windcorp/progressia/server/world/ChunkTickContext.java

@@ -1,55 +0,0 @@
-/*
- * Progressia
- * Copyright (C)  2020-2021  Wind Corporation 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 ru.windcorp.progressia.server.world;
-
-import java.util.function.Consumer;
-
-import glm.vec._3.i.Vec3i;
-import ru.windcorp.progressia.common.world.DefaultChunkData;
-import ru.windcorp.progressia.common.world.generic.GenericChunks;
-import ru.windcorp.progressia.common.world.rels.AbsFace;
-import ru.windcorp.progressia.server.world.block.BlockTickContext;
-
-public interface ChunkTickContext extends TickContext {
-
-	Vec3i getChunk();
-
-	default DefaultChunkLogic getChunkLogic() {
-		return getWorld().getChunk(getChunk());
-	}
-
-	default DefaultChunkData getChunkData() {
-		DefaultChunkLogic chunkLogic = getChunkLogic();
-		return chunkLogic == null ? null : chunkLogic.getData();
-	}
-	
-	default AbsFace getUp() {
-		return getChunkData().getUp();
-	}
-
-	default void forEachBlock(Consumer<BlockTickContext> action) {
-		TickContextMutable context = TickContextMutable.uninitialized();
-
-		GenericChunks.forEachBiC(blockInChunk -> {
-			context.rebuild().withServer(getServer()).withChunk(getChunk()).withBlockInChunk(blockInChunk).build();
-			action.accept(context);
-		});
-	}
-
-}

src/main/java/ru/windcorp/progressia/server/world/DefaultChunkLogic.java

@@ -34,9 +34,13 @@ import ru.windcorp.progressia.common.world.rels.BlockFace;
 import ru.windcorp.progressia.common.world.rels.RelFace;
 import ru.windcorp.progressia.common.world.TileDataStack;
 import ru.windcorp.progressia.common.world.TileDataReference;
+import ru.windcorp.progressia.server.Server;
 import ru.windcorp.progressia.server.world.block.BlockLogic;
 import ru.windcorp.progressia.server.world.block.BlockLogicRegistry;
 import ru.windcorp.progressia.server.world.block.TickableBlock;
+import ru.windcorp.progressia.server.world.context.ServerBlockContextRO;
+import ru.windcorp.progressia.server.world.context.ServerTileContextRO;
+import ru.windcorp.progressia.server.world.context.ServerWorldContextRO;
 import ru.windcorp.progressia.server.world.tasks.TickChunk;
 import ru.windcorp.progressia.server.world.ticking.TickingPolicy;
 import ru.windcorp.progressia.server.world.tile.TickableTile;
@@ -221,28 +225,45 @@ public class DefaultChunkLogic implements ChunkLogic {
 	}
 
 	private void tmp_generateTickLists() {
-		ChunkTickContext context = TickContextMutable.start().withChunk(this).build();
+		ServerWorldContextRO context = Server.getCurrentServer().createContext();
+		Vec3i blockInChunk = new Vec3i();
 		
-		context.forEachBlock(bctxt -> {
+		forEachBiW(location -> {
-			BlockLogic block = bctxt.getBlock();
+			
+			ServerBlockContextRO blockContext = context.push(location);
+			
+			BlockLogic block = blockContext.logic().getBlock();
+			Coordinates.convertInWorldToInChunk(location, blockInChunk);
 
 			if (!(block instanceof TickableBlock))
 				return;
 
-			if (((TickableBlock) block).getTickingPolicy(bctxt) == TickingPolicy.REGULAR) {
+			if (((TickableBlock) block).getTickingPolicy(blockContext) == TickingPolicy.REGULAR) {
-				tickingBlocks.add(Coordinates.convertInWorldToInChunk(bctxt.getBlockInWorld(), null));
+				tickingBlocks.add(blockInChunk);
 			}
 
-			bctxt.forEachFace(fctxt -> fctxt.forEachTile(tctxt -> {
+			for (RelFace face : RelFace.getFaces()) {
-				TileLogic tile = tctxt.getTile();
+				TileLogicStack stack = getTilesOrNull(blockInChunk, face);
+				if (stack == null || stack.isEmpty()) continue;
 				
-				if (!(tile instanceof TickableTile))
+				for (int i = 0; i < stack.size(); ++i) {
-					return;
+					ServerTileContextRO tileContext = blockContext.push(face, i);
 					
-				if (((TickableTile) tile).getTickingPolicy(tctxt) == TickingPolicy.REGULAR) {
+					TileLogic tile = stack.get(i);
-					tickingTiles.add(tctxt.getReference());
+
+					if (!(tile instanceof TickableTile))
+						return;
+
+					if (((TickableTile) tile).getTickingPolicy(tileContext) == TickingPolicy.REGULAR) {
+						tickingTiles.add(stack.getData().getReference(i));
+					}
+					
+					tileContext.pop();
 				}
-			}));
+			}
+			
+			blockContext.pop();
+			
 		});
 	}
 

src/main/java/ru/windcorp/progressia/server/world/DefaultWorldLogic.java

@@ -65,7 +65,7 @@ public class DefaultWorldLogic implements WorldLogic {
 			}
 		});
 
-		data.addListener(ChunkDataListeners.createAdder(new UpdateTriggerer(server)));
+		data.addListener(ChunkDataListeners.createAdder(new UpdateTriggerer(server.getWorldAccessor___really_bad_dont_use())));
 	}
 
 	@Override

src/main/java/ru/windcorp/progressia/server/world/TickAndUpdateUtil.java

@@ -24,19 +24,26 @@ import ru.windcorp.progressia.common.world.entity.EntityData;
 import ru.windcorp.progressia.common.world.rels.BlockFace;
 import ru.windcorp.progressia.server.Server;
 import ru.windcorp.progressia.server.world.block.BlockLogic;
-import ru.windcorp.progressia.server.world.block.BlockTickContext;
 import ru.windcorp.progressia.server.world.block.TickableBlock;
 import ru.windcorp.progressia.server.world.block.UpdateableBlock;
+import ru.windcorp.progressia.server.world.context.ServerBlockContext;
+import ru.windcorp.progressia.server.world.context.ServerTileContext;
+import ru.windcorp.progressia.server.world.context.ServerTileStackContext;
+import ru.windcorp.progressia.server.world.context.ServerWorldContext;
 import ru.windcorp.progressia.server.world.entity.EntityLogic;
 import ru.windcorp.progressia.server.world.entity.EntityLogicRegistry;
 import ru.windcorp.progressia.server.world.tile.TickableTile;
 import ru.windcorp.progressia.server.world.tile.TileLogic;
-import ru.windcorp.progressia.server.world.tile.TileTickContext;
 import ru.windcorp.progressia.server.world.tile.UpdateableTile;
 
 public class TickAndUpdateUtil {
 
-	public static void tickBlock(TickableBlock block, BlockTickContext context) {
+	public static void tickBlock(ServerBlockContext context) {
+		BlockLogic uncheckedBlock = context.logic().getBlock();
+		if (!(uncheckedBlock instanceof BlockLogic)) {
+			return;
+		}
+		TickableBlock block = (TickableBlock) uncheckedBlock;
 		try {
 			block.tick(context);
 		} catch (Exception e) {
@@ -44,16 +51,21 @@ public class TickAndUpdateUtil {
 		}
 	}
 
-	public static void tickBlock(DefaultWorldLogic world, Vec3i blockInWorld) {
+	public static void tickBlock(Server server, Vec3i blockInWorld) {
-		BlockLogic block = world.getBlock(blockInWorld);
+		BlockLogic block = server.getWorld().getBlock(blockInWorld);
-		if (!(block instanceof TickableBlock))
+		if (!(block instanceof TickableBlock)) {
-			return; // also checks nulls
+			return;
-
+		}
-		BlockTickContext tickContext = TickContextMutable.start().withWorld(world).withBlock(blockInWorld).build();
+		ServerBlockContext context = server.createContext().push(blockInWorld);
-		tickBlock((TickableBlock) block, tickContext);
+		tickBlock(context);
 	}
 
-	public static void tickTile(TickableTile tile, TileTickContext context) {
+	public static void tickTile(ServerTileContext context) {
+		TileLogic uncheckedTile = context.logic().getTile();
+		if (!(uncheckedTile instanceof TickableTile)) {
+			return;
+		}
+		TickableTile tile = (TickableTile) uncheckedTile;
 		try {
 			tile.tick(context);
 		} catch (Exception e) {
@@ -61,82 +73,88 @@ public class TickAndUpdateUtil {
 		}
 	}
 
-	public static void tickTile(DefaultWorldLogic world, Vec3i blockInWorld, BlockFace face, int layer) {
+	public static void tickTile(Server server, Vec3i blockInWorld, BlockFace face, int layer) {
-		TileLogic tile = world.getTile(blockInWorld, face, layer);
+		TileLogic tile = server.getWorld().getTile(blockInWorld, face, layer);
 		if (!(tile instanceof TickableTile)) {
 			return;
 		}
-
+		ServerTileContext context = server.createContext()
-		TileTickContext tickContext = TickContextMutable.start().withWorld(world).withBlock(blockInWorld).withFace(face)
+			.push(blockInWorld, face.relativize(server.getWorld().getUp(blockInWorld)), layer);
-			.withLayer(layer);
+		tickTile(context);
-		tickTile((TickableTile) tile, tickContext);
 	}
 
-	public static void tickTiles(DefaultWorldLogic world, Vec3i blockInWorld, BlockFace face) {
+	public static void tickTiles(Server server, Vec3i blockInWorld, BlockFace face) {
-		if (!world.isLocationLoaded(blockInWorld)) {
+		if (!server.getWorld().hasTiles(blockInWorld, face)) {
 			return;
 		}
 
-		TickContextMutable.start().withWorld(world).withBlock(blockInWorld).withFace(face).build()
+		ServerTileStackContext context = server.createContext()
-			.forEachTile(context -> {
+			.push(blockInWorld, face.relativize(server.getWorld().getUp(blockInWorld)));
-				TileLogic tile = context.getTile();
+		for (int i = 0; i < context.getTileCount(); ++i) {
-				if (tile instanceof TickableTile) {
+			tickTile(context.push(i));
-					tickTile((TickableTile) tile, context);
+			context.pop();
-				}
+		}
-			});
 	}
 
-	public static void updateBlock(UpdateableBlock block, BlockTickContext context) {
+	public static void updateBlock(ServerBlockContext context) {
+		BlockLogic uncheckedBlock = context.logic().getBlock();
+		if (!(uncheckedBlock instanceof BlockLogic)) {
+			return;
+		}
+		UpdateableBlock block = (UpdateableBlock) uncheckedBlock;
 		try {
 			block.update(context);
 		} catch (Exception e) {
-			throw CrashReports.report(e, "Could not update block {}", block);
+			throw CrashReports.report(e, "Could not update block %s", block);
 		}
 	}
 
-	public static void updateBlock(DefaultWorldLogic world, Vec3i blockInWorld) {
+	public static void updateBlock(Server server, Vec3i blockInWorld) {
-		BlockLogic block = world.getBlock(blockInWorld);
+		BlockLogic block = server.getWorld().getBlock(blockInWorld);
-		if (!(block instanceof UpdateableBlock))
+		if (!(block instanceof UpdateableBlock)) {
-			return; // also checks nulls
+			return;
-
+		}
-		BlockTickContext tickContext = TickContextMutable.start().withWorld(world).withBlock(blockInWorld).build();
+		ServerBlockContext context = server.createContext().push(blockInWorld);
-		updateBlock((UpdateableBlock) block, tickContext);
+		updateBlock(context);
 	}
 
-	public static void updateTile(UpdateableTile tile, TileTickContext context) {
+	public static void updateTile(ServerTileContext context) {
+		TileLogic uncheckedTile = context.logic().getTile();
+		if (!(uncheckedTile instanceof UpdateableTile)) {
+			return;
+		}
+		UpdateableTile tile = (UpdateableTile) uncheckedTile;
 		try {
 			tile.update(context);
 		} catch (Exception e) {
-			throw CrashReports.report(e, "Could not update tile {}", tile);
+			throw CrashReports.report(e, "Could not tick tile %s", tile);
 		}
 	}
 
-	public static void updateTile(DefaultWorldLogic world, Vec3i blockInWorld, BlockFace face, int layer) {
+	public static void updateTile(Server server, Vec3i blockInWorld, BlockFace face, int layer) {
-		TileLogic tile = world.getTile(blockInWorld, face, layer);
+		TileLogic tile = server.getWorld().getTile(blockInWorld, face, layer);
 		if (!(tile instanceof UpdateableTile)) {
 			return;
 		}
-
+		ServerTileContext context = server.createContext()
-		TileTickContext tickContext = TickContextMutable.start().withWorld(world).withBlock(blockInWorld).withFace(face)
+			.push(blockInWorld, face.relativize(server.getWorld().getUp(blockInWorld)), layer);
-			.withLayer(layer);
+		updateTile(context);
-		updateTile((UpdateableTile) tile, tickContext);
 	}
 
-	public static void updateTiles(DefaultWorldLogic world, Vec3i blockInWorld, BlockFace face) {
+	public static void updateTiles(Server server, Vec3i blockInWorld, BlockFace face) {
-		if (!world.isLocationLoaded(blockInWorld)) {
+		if (!server.getWorld().hasTiles(blockInWorld, face)) {
 			return;
 		}
 
-		TickContextMutable.start().withWorld(world).withBlock(blockInWorld).withFace(face).build()
+		ServerTileStackContext context = server.createContext()
-			.forEachTile(context -> {
+			.push(blockInWorld, face.relativize(server.getWorld().getUp(blockInWorld)));
-				TileLogic tile = context.getTile();
+		for (int i = 0; i < context.getTileCount(); ++i) {
-				if (tile instanceof UpdateableTile) {
+			updateTile(context.push(i));
-					updateTile((UpdateableTile) tile, context);
+			context.pop();
-				}
+		}
-			});
 	}
 
-	public static void tickEntity(EntityLogic logic, EntityData data, TickContext context) {
+	public static void tickEntity(EntityLogic logic, EntityData data, ServerWorldContext context) {
 		try {
 			logic.tick(data, context);
 		} catch (Exception e) {
@@ -148,7 +166,7 @@ public class TickAndUpdateUtil {
 		tickEntity(
 			EntityLogicRegistry.getInstance().get(data.getId()),
 			data,
-			TickContextMutable.start().withServer(server).build()
+			server.createContext()
 		);
 	}
 

src/main/java/ru/windcorp/progressia/server/world/TickContext.java

@@ -1,49 +0,0 @@
-/*
- * Progressia
- * Copyright (C)  2020-2021  Wind Corporation 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 ru.windcorp.progressia.server.world;
-
-import java.util.Random;
-
-import ru.windcorp.progressia.common.world.DefaultWorldData;
-import ru.windcorp.progressia.server.Server;
-import ru.windcorp.progressia.server.world.tasks.WorldAccessor;
-
-public interface TickContext {
-
-	float getTickLength();
-
-	Server getServer();
-
-	default DefaultWorldLogic getWorld() {
-		return getServer().getWorld();
-	}
-
-	default WorldAccessor getAccessor() {
-		return getServer().getWorldAccessor();
-	}
-
-	default Random getRandom() {
-		return getServer().getAdHocRandom();
-	}
-
-	default DefaultWorldData getWorldData() {
-		return getWorld().getData();
-	}
-
-}

src/main/java/ru/windcorp/progressia/server/world/TickContextMutable.java

@@ -1,497 +0,0 @@
-/*
- * Progressia
- * Copyright (C)  2020-2021  Wind Corporation 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 ru.windcorp.progressia.server.world;
-
-import java.util.Objects;
-import java.util.function.Consumer;
-import java.util.function.Function;
-
-import glm.vec._3.i.Vec3i;
-import ru.windcorp.progressia.common.world.DefaultChunkData;
-import ru.windcorp.progressia.common.world.Coordinates;
-import ru.windcorp.progressia.common.world.generic.TileGenericStackRO;
-import ru.windcorp.progressia.common.world.rels.BlockFace;
-import ru.windcorp.progressia.common.world.rels.RelFace;
-import ru.windcorp.progressia.common.world.TileDataStack;
-import ru.windcorp.progressia.common.world.TileDataReference;
-import ru.windcorp.progressia.server.Server;
-import ru.windcorp.progressia.server.world.block.BlockTickContext;
-import ru.windcorp.progressia.server.world.tile.TSTickContext;
-import ru.windcorp.progressia.server.world.tile.TileTickContext;
-
-public abstract class TickContextMutable implements BlockTickContext, TSTickContext, TileTickContext {
-
-	private static enum Role {
-		NONE, WORLD, CHUNK, BLOCK, TILE_STACK, TILE;
-	}
-
-	/*
-	 * TickContextMutable interface
-	 */
-
-	// Only TickContextMutable.Impl can extend; extend Impl if need be
-	private TickContextMutable() {
-	}
-
-	public abstract Builder.Empty rebuild();
-
-	/*
-	 * Static methods
-	 */
-
-	public static TickContextMutable uninitialized() {
-		return new Impl();
-	}
-
-	public static Builder.Empty start() {
-		return uninitialized().rebuild();
-	}
-
-	public static Builder.World copyWorld(TickContext context) {
-		return start().withServer(context.getServer());
-	}
-
-	public static Builder.Chunk copyChunk(ChunkTickContext context) {
-		return start().withChunk(context.getChunkLogic());
-	}
-
-	public static Builder.Block copyBlock(BlockTickContext context) {
-		return copyWorld(context).withBlock(context.getBlockInWorld());
-	}
-
-	public static Builder.TileStack copyTS(TSTickContext context) {
-		return copyBlock(context).withFace(context.getFace());
-	}
-
-	public static TileTickContext copyTile(TileTickContext context) {
-		return copyTS(context).withLayer(context.getLayer());
-	}
-
-	/*
-	 * Builder interfaces
-	 */
-
-	public static interface Builder {
-		TickContextMutable build();
-
-		public static interface Empty /* does not extend Builder */ {
-			World withServer(Server server);
-
-			default Builder.World withWorld(DefaultWorldLogic world) {
-				Objects.requireNonNull(world, "world");
-				return withServer(world.getServer());
-			}
-
-			default Builder.Chunk withChunk(DefaultChunkLogic chunk) {
-				Objects.requireNonNull(chunk, "chunk");
-				return withWorld(chunk.getWorld()).withChunk(chunk.getPosition());
-			}
-		}
-
-		public static interface World extends Builder {
-			Chunk withChunk(Vec3i chunk);
-
-			Block withBlock(Vec3i blockInWorld);
-
-			TileStack withTS(TileGenericStackRO<?, ?, ?, ?, ?> tileStack);
-
-			default Builder.Chunk withChunk(DefaultChunkData chunk) {
-				Objects.requireNonNull(chunk, "chunk");
-				return withChunk(chunk.getPosition());
-			}
-
-			default TileTickContext withTile(TileDataReference ref) {
-				Objects.requireNonNull(ref, "ref");
-				return withTS(ref.getStack()).withLayer(ref.getIndex());
-			}
-		}
-
-		public static interface Chunk extends Builder {
-			Builder.Block withBlockInChunk(Vec3i blockInChunk);
-		}
-
-		public static interface Block extends Builder {
-			Builder.TileStack withFace(BlockFace face);
-		}
-
-		public static interface TileStack extends Builder {
-			TickContextMutable withLayer(int layer);
-		}
-	}
-
-	/*
-	 * Impl
-	 */
-
-	public static class Impl
-		extends TickContextMutable
-		implements Builder.Empty, Builder.World, Builder.Chunk, Builder.Block, Builder.TileStack {
-
-		protected Impl() {
-		}
-
-		protected Server server;
-		protected final Vec3i chunk = new Vec3i();
-		protected final Vec3i blockInWorld = new Vec3i();
-		protected RelFace face;
-		protected int layer;
-
-		protected Role role = Role.NONE;
-		protected boolean isBeingBuilt = false;
-
-		/**
-		 * Updated lazily
-		 */
-		protected final Vec3i blockInChunk = new Vec3i();
-
-		/*
-		 * TickContextMutable
-		 */
-
-		@Override
-		public Server getServer() {
-			checkContextState(Role.WORLD);
-			return this.server;
-		}
-
-		@Override
-		public float getTickLength() {
-			checkContextState(Role.WORLD);
-			return (float) this.server.getTickLength();
-		}
-
-		@Override
-		public Vec3i getChunk() {
-			checkContextState(Role.CHUNK);
-			return this.chunk;
-		}
-
-		@Override
-		public Vec3i getBlockInWorld() {
-			checkContextState(Role.BLOCK);
-			return this.blockInWorld;
-		}
-
-		@Override
-		public RelFace getFace() {
-			checkContextState(Role.TILE_STACK);
-			return this.face;
-		}
-
-		@Override
-		public int getLayer() {
-			checkContextState(Role.TILE);
-			return this.layer;
-		}
-
-		@Override
-		public Builder.Empty rebuild() {
-			this.role = Role.NONE;
-			this.isBeingBuilt = true;
-
-			this.server = null;
-			this.chunk.set(0);
-			this.blockInWorld.set(0);
-			this.face = null;
-			this.layer = -1;
-
-			return this;
-		}
-
-		/*
-		 * Builder
-		 * memo: do NOT use Context getters, they throw ISEs
-		 */
-
-		@Override
-		public TickContextMutable build() {
-			checkBuilderState(null);
-			this.isBeingBuilt = false;
-			return this;
-		}
-
-		@Override
-		public World withServer(Server server) {
-			Objects.requireNonNull(server, "server");
-			checkBuilderState(Role.NONE);
-			this.server = server;
-			this.role = Role.WORLD;
-			return this;
-		}
-
-		@Override
-		public Chunk withChunk(Vec3i chunk) {
-			Objects.requireNonNull(chunk, "chunk");
-			checkBuilderState(Role.WORLD);
-
-			this.chunk.set(chunk.x, chunk.y, chunk.z);
-
-			this.role = Role.CHUNK;
-			return this;
-		}
-
-		@Override
-		public Block withBlock(Vec3i blockInWorld) {
-			Objects.requireNonNull(blockInWorld, "blockInWorld");
-			checkBuilderState(Role.WORLD);
-
-			this.blockInWorld.set(blockInWorld.x, blockInWorld.y, blockInWorld.z);
-			Coordinates.convertInWorldToChunk(blockInWorld, this.chunk);
-
-			this.role = Role.BLOCK;
-			return this;
-		}
-
-		@Override
-		public TileStack withTS(TileGenericStackRO<?, ?, ?, ?, ?> tileStack) {
-			Objects.requireNonNull(tileStack, "tileStack");
-
-			return withBlock(
-				tileStack.getBlockInWorld(this.blockInWorld) // This is safe
-			).withFace(tileStack.getFace());
-		}
-
-		@Override
-		public Block withBlockInChunk(Vec3i blockInChunk) {
-			Objects.requireNonNull(blockInChunk, "blockInChunk");
-			checkBuilderState(Role.CHUNK);
-
-			Coordinates.getInWorld(this.chunk, blockInChunk, this.blockInWorld);
-
-			this.role = Role.BLOCK;
-			return this;
-		}
-
-		@Override
-		public TileStack withFace(BlockFace face) {
-			Objects.requireNonNull(face, "face");
-			checkBuilderState(Role.BLOCK);
-
-			this.face = face.relativize(server.getWorld().getChunk(chunk).getUp());
-
-			this.role = Role.TILE_STACK;
-			return this;
-		}
-
-		@Override
-		public TickContextMutable withLayer(int layer) {
-			checkBuilderState(Role.TILE);
-
-			this.layer = layer;
-
-			this.role = Role.TILE;
-			return build();
-		}
-
-		/*
-		 * Optimization
-		 */
-
-		@Override
-		public Vec3i getBlockInChunk() {
-			return Coordinates.convertInWorldToInChunk(getBlockInWorld(), this.blockInChunk);
-		}
-
-		@Override
-		public void forEachBlock(Consumer<BlockTickContext> action) {
-			checkContextState(Role.CHUNK);
-
-			Vec3i v = this.blockInWorld;
-
-			int previousX = v.x;
-			int previousY = v.y;
-			int previousZ = v.z;
-			Role previousRole = this.role;
-
-			this.role = Role.BLOCK;
-
-			final int minX = Coordinates.getInWorld(chunk.x, 0);
-			final int minY = Coordinates.getInWorld(chunk.y, 0);
-			final int minZ = Coordinates.getInWorld(chunk.z, 0);
-			final int size = DefaultChunkData.BLOCKS_PER_CHUNK;
-
-			for (v.x = minX; v.x < minX + size; ++v.x) {
-				for (v.y = minY; v.y < minY + size; ++v.y) {
-					for (v.z = minZ; v.z < minZ + size; ++v.z) {
-						action.accept(this);
-					}
-				}
-			}
-
-			this.role = previousRole;
-			blockInWorld.set(previousX, previousY, previousZ);
-		}
-
-		@Override
-		public void forEachFace(Consumer<TSTickContext> action) {
-			checkContextState(Role.BLOCK);
-			RelFace previousFace = this.face;
-			Role previousRole = this.role;
-
-			this.role = Role.TILE_STACK;
-			for (int i = 0; i < BlockFace.BLOCK_FACE_COUNT; ++i) {
-				this.face = RelFace.getFaces().get(i);
-				action.accept(this);
-			}
-
-			this.role = previousRole;
-			this.face = previousFace;
-		}
-
-		@Override
-		public <R> R evalNeighbor(Vec3i direction, Function<BlockTickContext, R> action) {
-			this.blockInWorld.add(direction);
-			R result = action.apply(this);
-			this.blockInWorld.sub(direction);
-
-			return result;
-		}
-
-		@Override
-		public void forNeighbor(Vec3i direction, Consumer<BlockTickContext> action) {
-			this.blockInWorld.add(direction);
-			action.accept(this);
-			this.blockInWorld.sub(direction);
-		}
-
-		@Override
-		public boolean forEachTile(Consumer<TileTickContext> action) {
-			checkContextState(Role.TILE_STACK);
-			int previousLayer = this.layer;
-			Role previousRole = this.role;
-
-			this.role = Role.TILE;
-			TileDataStack stack = getTDSOrNull();
-			if (stack == null || stack.isEmpty())
-				return false;
-
-			for (this.layer = 0; this.layer < stack.size(); ++this.layer) {
-				action.accept(this);
-			}
-
-			this.role = previousRole;
-			this.layer = previousLayer;
-			return true;
-		}
-
-		@Override
-		public <R> R evalComplementary(Function<TSTickContext, R> action) {
-			Objects.requireNonNull(action, "action");
-			checkContextState(Role.TILE_STACK);
-
-			Vec3i vector = this.face.getVector(getUp());
-			
-			this.blockInWorld.add(vector);
-			this.face = this.face.getCounter();
-			R result = action.apply(this);
-			this.face = this.face.getCounter();
-			this.blockInWorld.sub(vector);
-
-			return result;
-		}
-
-		@Override
-		public void forComplementary(Consumer<TSTickContext> action) {
-			Objects.requireNonNull(action, "action");
-			checkContextState(Role.TILE_STACK);
-
-			Vec3i vector = this.face.getVector(getUp());
-			
-			this.blockInWorld.add(vector);
-			this.face = this.face.getCounter();
-			action.accept(this);
-			this.face = this.face.getCounter();
-			this.blockInWorld.sub(vector);
-		}
-
-		/*
-		 * Misc
-		 */
-
-		protected void checkContextState(Role requiredRole) {
-			if (isBeingBuilt) {
-				throw new IllegalStateException("This context is still being built");
-			}
-
-			if ((role == null) || (requiredRole.compareTo(role) > 0)) {
-				throw new IllegalStateException(
-					"This context is currently initialized as " + role + "; requested " + requiredRole
-				);
-			}
-		}
-
-		protected void checkBuilderState(Role requiredRole) {
-			if (!isBeingBuilt) {
-				throw new IllegalStateException("This context is already built");
-			}
-
-			if (requiredRole == null) {
-				if (role == Role.NONE) {
-					throw new IllegalStateException("This context is currently not initialized");
-				}
-			} else {
-				if (role != requiredRole) {
-					throw new IllegalStateException(
-						"This context is currently initialized as " + role + "; requested " + requiredRole
-					);
-				}
-			}
-		}
-
-		@Override
-		public String toString() {
-			final String format;
-
-			switch (this.role) {
-			case WORLD:
-				format = "TickContext";
-				break;
-			case CHUNK:
-				format = "(%2$d; %3$d; %4$d)";
-				break;
-			case BLOCK:
-				format = "(%5$d; %6$d; %7$d)";
-				break;
-			case TILE_STACK:
-				format = "((%5$d; %6$d; %7$d); %8$6s)";
-				break;
-			case TILE:
-				format = "((%5$d; %6$d; %7$d); %8$6s; %9$d)";
-				break;
-			case NONE:
-			default:
-				format = "Uninitialized TickContextMutable";
-				break;
-			}
-
-			return String.format(
-				format,
-				this.chunk.x,
-				this.chunk.y,
-				this.chunk.z,
-				this.blockInWorld.x,
-				this.blockInWorld.y,
-				this.blockInWorld.z,
-				this.face,
-				this.layer
-			);
-		}
-	}
-
-}

src/main/java/ru/windcorp/progressia/server/world/UpdateTriggerer.java

@@ -25,14 +25,14 @@ import ru.windcorp.progressia.common.world.Coordinates;
 import ru.windcorp.progressia.common.world.block.BlockData;
 import ru.windcorp.progressia.common.world.rels.RelFace;
 import ru.windcorp.progressia.common.world.tile.TileData;
-import ru.windcorp.progressia.server.Server;
+import ru.windcorp.progressia.server.world.tasks.WorldAccessor;
 
 public class UpdateTriggerer implements ChunkDataListener {
 
-	private final Server server;
+	private final WorldAccessor worldAccessor;
 
-	public UpdateTriggerer(Server server) {
+	public UpdateTriggerer(WorldAccessor worldAccessor) {
-		this.server = server;
+		this.worldAccessor = worldAccessor;
 	}
 
 	@Override
@@ -42,7 +42,7 @@ public class UpdateTriggerer implements ChunkDataListener {
 		BlockData previous,
 		BlockData current
 	) {
-		server.getWorldAccessor().triggerUpdates(Coordinates.getInWorld(chunk.getPosition(), blockInChunk, null));
+		worldAccessor.triggerUpdates(Coordinates.getInWorld(chunk.getPosition(), blockInChunk, null));
 	}
 
 	@Override
@@ -53,7 +53,7 @@ public class UpdateTriggerer implements ChunkDataListener {
 		TileData tile,
 		boolean wasAdded
 	) {
-		server.getWorldAccessor().triggerUpdates(Coordinates.getInWorld(chunk.getPosition(), blockInChunk, null), face);
+		worldAccessor.triggerUpdates(Coordinates.getInWorld(chunk.getPosition(), blockInChunk, null), face);
 	}
 
 }

src/main/java/ru/windcorp/progressia/server/world/block/BlockLogic.java

@@ -21,6 +21,7 @@ package ru.windcorp.progressia.server.world.block;
 import ru.windcorp.progressia.common.util.namespaces.Namespaced;
 import ru.windcorp.progressia.common.world.generic.BlockGeneric;
 import ru.windcorp.progressia.common.world.rels.RelFace;
+import ru.windcorp.progressia.server.world.context.ServerBlockContextRO;
 
 public class BlockLogic extends Namespaced implements BlockGeneric {
 
@@ -28,7 +29,7 @@ public class BlockLogic extends Namespaced implements BlockGeneric {
 		super(id);
 	}
 
-	public boolean isSolid(BlockTickContext context, RelFace face) {
+	public boolean isSolid(ServerBlockContextRO context, RelFace face) {
 		return isSolid(face);
 	}
 
@@ -36,7 +37,7 @@ public class BlockLogic extends Namespaced implements BlockGeneric {
 		return true;
 	}
 
-	public boolean isTransparent(BlockTickContext context) {
+	public boolean isTransparent(ServerBlockContextRO context) {
 		return isTransparent();
 	}
 

src/main/java/ru/windcorp/progressia/server/world/block/BlockTickContext.java

@@ -1,114 +0,0 @@
-/*
- * Progressia
- * Copyright (C)  2020-2021  Wind Corporation 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 ru.windcorp.progressia.server.world.block;
-
-import java.util.Objects;
-import java.util.function.Consumer;
-import java.util.function.Function;
-
-import glm.vec._3.i.Vec3i;
-import ru.windcorp.progressia.common.world.Coordinates;
-import ru.windcorp.progressia.common.world.block.BlockData;
-import ru.windcorp.progressia.common.world.rels.AbsFace;
-import ru.windcorp.progressia.common.world.rels.BlockRelation;
-import ru.windcorp.progressia.server.world.ChunkTickContext;
-import ru.windcorp.progressia.server.world.TickContextMutable;
-import ru.windcorp.progressia.server.world.tile.TSTickContext;
-
-public interface BlockTickContext extends ChunkTickContext {
-
-	/**
-	 * Returns the current world coordinates.
-	 * 
-	 * @return the world coordinates of the block being ticked
-	 */
-	Vec3i getBlockInWorld();
-
-	default Vec3i getBlockInChunk() {
-		return Coordinates.convertInWorldToInChunk(getBlockInWorld(), null);
-	}
-
-	default BlockLogic getBlock() {
-		return getWorld().getBlock(getBlockInWorld());
-	}
-
-	default BlockData getBlockData() {
-		return getWorldData().getBlock(getBlockInWorld());
-	}
-
-	default void forEachFace(Consumer<TSTickContext> action) {
-		Objects.requireNonNull(action, "action");
-		TickContextMutable context = TickContextMutable.uninitialized();
-
-		for (AbsFace face : AbsFace.getFaces()) {
-			context.rebuild().withServer(getServer()).withBlock(getBlockInWorld()).withFace(face).build();
-			action.accept(context);
-		}
-	}
-
-	default BlockTickContext getNeighbor(Vec3i direction) {
-		Objects.requireNonNull(direction, "direction");
-		return TickContextMutable.copyWorld(this).withBlock(getBlockInWorld().add_(direction)).build();
-	}
-
-	default BlockTickContext getNeighbor(BlockRelation relation) {
-		Objects.requireNonNull(relation, "relation");
-		return getNeighbor(relation.getVector(getChunkData().getUp()));
-	}
-
-	default <R> R evalNeighbor(Vec3i direction, Function<BlockTickContext, R> action) {
-		Objects.requireNonNull(action, "action");
-		Objects.requireNonNull(direction, "direction");
-		return action.apply(getNeighbor(direction));
-	}
-
-	default <R> R evalNeighbor(BlockRelation relation, Function<BlockTickContext, R> action) {
-		Objects.requireNonNull(action, "action");
-		Objects.requireNonNull(relation, "relation");
-		return evalNeighbor(relation.getVector(getChunkData().getUp()), action);
-	}
-
-	default void forNeighbor(Vec3i direction, Consumer<BlockTickContext> action) {
-		Objects.requireNonNull(action, "action");
-		Objects.requireNonNull(direction, "direction");
-		evalNeighbor(direction, (Function<BlockTickContext, Void>) ctxt -> {
-			action.accept(ctxt);
-			return null;
-		});
-	}
-
-	default void forNeighbor(BlockRelation relation, Consumer<BlockTickContext> action) {
-		Objects.requireNonNull(action, "action");
-		Objects.requireNonNull(relation, "relation");
-		forNeighbor(relation.getVector(getChunkData().getUp()), action);
-	}
-
-	/*
-	 * Convenience methods - changes
-	 */
-
-	default void setThisBlock(BlockData block) {
-		getAccessor().setBlock(getBlockInWorld(), block);
-	}
-
-	default void setThisBlock(String id) {
-		getAccessor().setBlock(getBlockInWorld(), id);
-	}
-
-}

src/main/java/ru/windcorp/progressia/server/world/block/TickableBlock.java

@@ -18,12 +18,14 @@
  
 package ru.windcorp.progressia.server.world.block;
 
+import ru.windcorp.progressia.server.world.context.ServerBlockContext;
+import ru.windcorp.progressia.server.world.context.ServerBlockContextRO;
 import ru.windcorp.progressia.server.world.ticking.TickingPolicy;
 
 public interface TickableBlock {
 
-	void tick(BlockTickContext context);
+	void tick(ServerBlockContext context);
 
-	TickingPolicy getTickingPolicy(BlockTickContext context);
+	TickingPolicy getTickingPolicy(ServerBlockContextRO context);
 
 }

src/main/java/ru/windcorp/progressia/server/world/block/UpdateableBlock.java

@@ -18,18 +18,10 @@
  
 package ru.windcorp.progressia.server.world.block;
 
-import org.apache.logging.log4j.LogManager;
+import ru.windcorp.progressia.server.world.context.ServerBlockContext;
 
 public interface UpdateableBlock {
 
-	default void update(BlockTickContext context) {
+	void update(ServerBlockContext context);
-		LogManager.getLogger().info(
-			"Updating block {} @ ({}; {}; {})",
-			context.getBlock(),
-			context.getBlockInWorld().x,
-			context.getBlockInWorld().y,
-			context.getBlockInWorld().z
-		);
-	}
 
 }

src/main/java/ru/windcorp/progressia/server/world/entity/EntityLogic.java

@@ -20,7 +20,7 @@ package ru.windcorp.progressia.server.world.entity;
 
 import ru.windcorp.progressia.common.util.namespaces.Namespaced;
 import ru.windcorp.progressia.common.world.entity.EntityData;
-import ru.windcorp.progressia.server.world.TickContext;
+import ru.windcorp.progressia.server.world.context.ServerWorldContext;
 
 public class EntityLogic extends Namespaced {
 
@@ -28,7 +28,7 @@ public class EntityLogic extends Namespaced {
 		super(id);
 	}
 
-	public void tick(EntityData entity, TickContext context) {
+	public void tick(EntityData entity, ServerWorldContext context) {
 		entity.incrementAge(context.getTickLength());
 	}
 

src/main/java/ru/windcorp/progressia/server/world/tasks/BlockTriggeredUpdate.java

@@ -25,7 +25,6 @@ import ru.windcorp.progressia.common.world.Coordinates;
 import ru.windcorp.progressia.common.world.rels.AbsFace;
 import ru.windcorp.progressia.server.Server;
 import ru.windcorp.progressia.server.world.TickAndUpdateUtil;
-import ru.windcorp.progressia.server.world.DefaultWorldLogic;
 
 class BlockTriggeredUpdate extends CachedEvaluation {
 
@@ -39,13 +38,11 @@ class BlockTriggeredUpdate extends CachedEvaluation {
 	public void evaluate(Server server) {
 		Vec3i cursor = new Vec3i(blockInWorld.x, blockInWorld.y, blockInWorld.z);
 
-		DefaultWorldLogic world = server.getWorld();
-
 		for (AbsFace face : AbsFace.getFaces()) {
-			TickAndUpdateUtil.updateTiles(world, cursor, face);
+			TickAndUpdateUtil.updateTiles(server, cursor, face);
 			cursor.add(face.getVector());
-			TickAndUpdateUtil.updateBlock(world, cursor);
+			TickAndUpdateUtil.updateBlock(server, cursor);
-			TickAndUpdateUtil.updateTiles(world, cursor, face.getCounter());
+			TickAndUpdateUtil.updateTiles(server, cursor, face.getCounter());
 			cursor.sub(face.getVector());
 		}
 	}

src/main/java/ru/windcorp/progressia/server/world/tasks/ChangeEntity.java

@@ -21,6 +21,7 @@ package ru.windcorp.progressia.server.world.tasks;
 import java.util.function.Consumer;
 
 import glm.vec._3.i.Vec3i;
+import ru.windcorp.progressia.common.state.StateChange;
 import ru.windcorp.progressia.common.world.entity.EntityData;
 import ru.windcorp.progressia.common.world.entity.PacketChangeEntity;
 import ru.windcorp.progressia.server.Server;
@@ -36,7 +37,7 @@ class ChangeEntity extends CachedChange {
 		super(disposer);
 	}
 
-	public <T extends EntityData> void set(T entity, StateChange<T> change) {
+	public void set(EntityData entity, StateChange<?> change) {
 		if (this.entity != null)
 			throw new IllegalStateException("Entity is not null. Current: " + this.entity + "; requested: " + entity);
 

src/main/java/ru/windcorp/progressia/server/world/tasks/StateChange.java

@@ -1,24 +0,0 @@
-/*
- * Progressia
- * Copyright (C)  2020-2021  Wind Corporation 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 ru.windcorp.progressia.server.world.tasks;
-
-@FunctionalInterface
-public interface StateChange<T> {
-	void change(T object);
-}

src/main/java/ru/windcorp/progressia/server/world/tasks/TickChunk.java

@@ -27,17 +27,22 @@ import com.google.common.collect.ImmutableList;
 
 import glm.vec._3.i.Vec3i;
 import ru.windcorp.progressia.common.util.FloatMathUtil;
+import ru.windcorp.progressia.common.util.Vectors;
+import ru.windcorp.progressia.common.world.Coordinates;
 import ru.windcorp.progressia.common.world.DefaultChunkData;
 import ru.windcorp.progressia.common.world.rels.AbsFace;
 import ru.windcorp.progressia.common.world.TileDataStack;
+import ru.windcorp.progressia.common.world.generic.ChunkGenericRO;
 import ru.windcorp.progressia.server.Server;
 import ru.windcorp.progressia.server.world.DefaultChunkLogic;
-import ru.windcorp.progressia.server.world.TickContextMutable;
 import ru.windcorp.progressia.server.world.block.BlockLogic;
 import ru.windcorp.progressia.server.world.block.TickableBlock;
+import ru.windcorp.progressia.server.world.context.ServerBlockContext;
+import ru.windcorp.progressia.server.world.context.ServerTileContext;
+import ru.windcorp.progressia.server.world.context.ServerTileStackContext;
+import ru.windcorp.progressia.server.world.context.ServerWorldContext;
 import ru.windcorp.progressia.server.world.ticking.Evaluation;
 import ru.windcorp.progressia.server.world.ticking.TickingPolicy;
-import ru.windcorp.progressia.server.world.tile.TSTickContext;
 import ru.windcorp.progressia.server.world.tile.TickableTile;
 import ru.windcorp.progressia.server.world.tile.TileLogic;
 import static ru.windcorp.progressia.common.world.DefaultChunkData.BLOCKS_PER_CHUNK;
@@ -82,11 +87,11 @@ public class TickChunk extends Evaluation {
 		if (!chunk.hasTickingBlocks())
 			return;
 
-		TickContextMutable context = TickContextMutable.uninitialized();
+		ServerWorldContext context = server.createContext();
 
 		chunk.forEachTickingBlock((blockInChunk, block) -> {
-			context.rebuild().withChunk(chunk).withBlockInChunk(blockInChunk).build();
+			((TickableBlock) block).tick(contextPushBiC(context, chunk, blockInChunk));
-			((TickableBlock) block).tick(context);
+			context.pop();
 		});
 	}
 
@@ -94,11 +99,14 @@ public class TickChunk extends Evaluation {
 		if (!chunk.hasTickingTiles())
 			return;
 
-		TickContextMutable context = TickContextMutable.uninitialized();
+		ServerWorldContext context = server.createContext();
+		Vec3i blockInWorld = new Vec3i();
 
 		chunk.forEachTickingTile((ref, tile) -> {
-			context.rebuild().withServer(server).withTile(ref);
+			((TickableTile) tile).tick(
-			((TickableTile) tile).tick(context);
+				context.push(ref.getStack().getBlockInWorld(blockInWorld), ref.getStack().getFace(), ref.getIndex())
+			);
+			context.pop();
 		});
 	}
 
@@ -144,7 +152,7 @@ public class TickChunk extends Evaluation {
 			return;
 		TickableBlock tickable = (TickableBlock) block;
 
-		TickContextMutable context = TickContextMutable.start().withChunk(chunk).withBlockInChunk(blockInChunk).build();
+		ServerBlockContext context = contextPushBiC(server.createContext(), chunk, blockInChunk);
 
 		if (tickable.getTickingPolicy(context) != TickingPolicy.RANDOM)
 			return;
@@ -164,18 +172,22 @@ public class TickChunk extends Evaluation {
 		if (tiles == null || tiles.isEmpty())
 			return;
 
-		TSTickContext context = TickContextMutable.start().withServer(server).withTS(tiles).build();
+		ServerTileStackContext context = contextPushBiC(server.createContext(), chunk, blockInChunk).push(face.relativize(chunk.getUp()));
 
-		context.forEachTile(tctxt -> {
+		for (int i = 0; i < tiles.size(); ++i) {
-			TileLogic logic = tctxt.getTile();
+			ServerTileContext tileContext = context.push(i);
+			
+			TileLogic logic = tileContext.logic().getTile();
 			if (!(logic instanceof TickableTile))
 				return;
 			TickableTile tickable = (TickableTile) logic;
 
-			if (tickable.getTickingPolicy(tctxt) != TickingPolicy.RANDOM)
+			if (tickable.getTickingPolicy(tileContext) != TickingPolicy.RANDOM)
 				return;
-			tickable.tick(tctxt);
+			tickable.tick(tileContext);
-		});
+			
+			tileContext.pop();
+		}
 	}
 
 	private float computeRandomTicks(Server server) {
@@ -184,6 +196,18 @@ public class TickChunk extends Evaluation {
 			server.getTickLength());
 	}
 
+	private ServerBlockContext contextPushBiC(
+		ServerWorldContext context,
+		ChunkGenericRO<?, ?, ?, ?, ?> chunk,
+		Vec3i blockInChunk
+	) {
+		Vec3i blockInWorld = Vectors.grab3i();
+		Coordinates.getInWorld(chunk.getPosition(), blockInChunk, blockInWorld);
+		ServerBlockContext blockContext = context.push(blockInWorld);
+		Vectors.release(blockInWorld);
+		return blockContext;
+	}
+
 	@Override
 	public void getRelevantChunk(Vec3i output) {
 		Vec3i p = chunk.getData().getPosition();

src/main/java/ru/windcorp/progressia/server/world/tasks/TileTriggeredUpdate.java

@@ -25,7 +25,6 @@ import ru.windcorp.progressia.common.world.Coordinates;
 import ru.windcorp.progressia.common.world.rels.AbsFace;
 import ru.windcorp.progressia.server.Server;
 import ru.windcorp.progressia.server.world.TickAndUpdateUtil;
-import ru.windcorp.progressia.server.world.DefaultWorldLogic;
 
 class TileTriggeredUpdate extends CachedEvaluation {
 
@@ -40,17 +39,15 @@ class TileTriggeredUpdate extends CachedEvaluation {
 	public void evaluate(Server server) {
 		Vec3i cursor = new Vec3i(blockInWorld.x, blockInWorld.y, blockInWorld.z);
 
-		DefaultWorldLogic world = server.getWorld();
+		// Update facemates (also self)
-
+		TickAndUpdateUtil.updateTiles(server, cursor, face);
-		TickAndUpdateUtil.updateTiles(world, cursor, face); // Update facemates
+		// Update block on one side
-															// (also self)
+		TickAndUpdateUtil.updateBlock(server, cursor);
-		TickAndUpdateUtil.updateBlock(world, cursor); // Update block on one
-														// side
 		cursor.add(face.getVector());
-		TickAndUpdateUtil.updateBlock(world, cursor); // Update block on the
+		// Update block on the other side
-														// other side
+		TickAndUpdateUtil.updateBlock(server, cursor);
-		TickAndUpdateUtil.updateTiles(world, cursor, face.getCounter()); // Update
+		// Update complement
-																			// complement
+		TickAndUpdateUtil.updateTiles(server, cursor, face.getCounter());
 	}
 
 	public void init(Vec3i blockInWorld, AbsFace face) {

src/main/java/ru/windcorp/progressia/server/world/tasks/WorldAccessor.java

@@ -21,17 +21,19 @@ package ru.windcorp.progressia.server.world.tasks;
 import java.util.function.Consumer;
 
 import glm.vec._3.i.Vec3i;
+import ru.windcorp.progressia.common.state.StateChange;
+import ru.windcorp.progressia.common.state.StatefulObject;
 import ru.windcorp.progressia.common.util.MultiLOC;
 import ru.windcorp.progressia.common.world.block.BlockData;
-import ru.windcorp.progressia.common.world.block.BlockDataRegistry;
 import ru.windcorp.progressia.common.world.entity.EntityData;
+import ru.windcorp.progressia.common.world.generic.EntityGeneric;
 import ru.windcorp.progressia.common.world.rels.BlockFace;
 import ru.windcorp.progressia.common.world.tile.TileData;
-import ru.windcorp.progressia.common.world.tile.TileDataRegistry;
 import ru.windcorp.progressia.server.Server;
+import ru.windcorp.progressia.server.world.context.impl.ReportingServerContext;
 import ru.windcorp.progressia.server.world.ticking.TickerTask;
 
-public class WorldAccessor {
+public class WorldAccessor implements ReportingServerContext.ChangeListener {
 
 	private final MultiLOC cache;
 	{
@@ -54,38 +56,52 @@ public class WorldAccessor {
 		this.server = server;
 	}
 
-	public void setBlock(Vec3i blockInWorld, BlockData block) {
+	@Override
+	public void onBlockSet(Vec3i blockInWorld, BlockData block) {
 		SetBlock change = cache.grab(SetBlock.class);
 		change.getPacket().set(block, blockInWorld);
 		server.requestChange(change);
 	}
 
-	public void setBlock(Vec3i blockInWorld, String id) {
+	@Override
-		setBlock(blockInWorld, BlockDataRegistry.getInstance().get(id));
+	public void onTileAdded(Vec3i blockInWorld, BlockFace face, TileData tile) {
-	}
-
-	public void addTile(Vec3i blockInWorld, BlockFace face, TileData tile) {
 		AddTile change = cache.grab(AddTile.class);
 		change.getPacket().set(tile, blockInWorld, face.resolve(server.getWorld().getUp(blockInWorld)));
 		server.requestChange(change);
 	}
 
-	public void addTile(Vec3i blockInWorld, BlockFace face, String id) {
+	@Override
-		addTile(blockInWorld, face, TileDataRegistry.getInstance().get(id));
+	public void onTileRemoved(Vec3i blockInWorld, BlockFace face, int tag) {
-	}
-
-	public void removeTile(Vec3i blockInWorld, BlockFace face, int tag) {
 		RemoveTile change = cache.grab(RemoveTile.class);
 		change.getPacket().set(blockInWorld, face.resolve(server.getWorld().getUp(blockInWorld)), tag);
 		server.requestChange(change);
 	}
 	
-	public <T extends EntityData> void changeEntity(
+	@Override
-		T entity,
+	public void onEntityAdded(EntityData entity) {
-		StateChange<T> stateChange
+		// TODO Auto-generated method stub
+		
+	}
+	
+	@Override
+	public void onEntityRemoved(long entityId) {
+		// TODO Auto-generated method stub
+		
+	}
+	
+	@Override
+	public void onTimeChanged(float change) {
+		// TODO Auto-generated method stub
+		System.err.println("WorldAccessor.onTimeChanged() NYI!");
+	}
+
+	@Override
+	public <SE extends StatefulObject & EntityGeneric> void onEntityChanged(
+		SE entity,
+		StateChange<SE> stateChange
 	) {
 		ChangeEntity change = cache.grab(ChangeEntity.class);
-		change.set(entity, stateChange);
+		change.set((EntityData) entity, stateChange);
 		server.requestChange(change);
 	}
 

src/main/java/ru/windcorp/progressia/server/world/tile/HangingTileLogic.java

@@ -19,6 +19,8 @@
 package ru.windcorp.progressia.server.world.tile;
 
 import ru.windcorp.progressia.server.world.block.BlockLogic;
+import ru.windcorp.progressia.server.world.context.ServerTileContext;
+import ru.windcorp.progressia.server.world.context.ServerTileContextRO;
 
 public class HangingTileLogic extends TileLogic implements UpdateableTile {
 
@@ -27,15 +29,15 @@ public class HangingTileLogic extends TileLogic implements UpdateableTile {
 	}
 
 	@Override
-	public void update(TileTickContext context) {
+	public void update(ServerTileContext context) {
 		if (!canOccupyFace(context)) {
-			context.removeThisTile();
+			context.removeTile();
 		}
 	}
 
 	@Override
-	public boolean canOccupyFace(TileTickContext context) {
+	public boolean canOccupyFace(ServerTileContextRO context) {
-		BlockLogic host = context.getBlock();
+		BlockLogic host = context.logic().getBlock();
 		if (host == null)
 			return false;
 
@@ -45,13 +47,14 @@ public class HangingTileLogic extends TileLogic implements UpdateableTile {
 		if (canBeSquashed(context))
 			return true;
 
-		return context.evalComplementary(ctxt -> {
+		context.pushOpposite();
-			BlockLogic complHost = ctxt.getBlock();
+		BlockLogic complHost = context.logic().getBlock();
-			return complHost == null || !complHost.isSolid(ctxt, context.getFace());
+		boolean result = complHost == null || !complHost.isSolid(context, context.getFace());
-		});
+		context.pop();
+		return result;
 	}
 
-	public boolean canBeSquashed(TileTickContext context) {
+	public boolean canBeSquashed(ServerTileContextRO context) {
 		return false;
 	}
 

src/main/java/ru/windcorp/progressia/server/world/tile/TSTickContext.java

@@ -1,113 +0,0 @@
-/*
- * Progressia
- * Copyright (C)  2020-2021  Wind Corporation 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 ru.windcorp.progressia.server.world.tile;
-
-import java.util.Objects;
-import java.util.function.Consumer;
-import java.util.function.Function;
-
-import ru.windcorp.progressia.common.world.DefaultChunkData;
-import ru.windcorp.progressia.common.world.rels.RelFace;
-import ru.windcorp.progressia.common.world.TileDataStack;
-import ru.windcorp.progressia.server.world.DefaultChunkLogic;
-import ru.windcorp.progressia.server.world.TickContextMutable;
-import ru.windcorp.progressia.server.world.TileLogicStackRO;
-import ru.windcorp.progressia.server.world.block.BlockTickContext;
-
-public interface TSTickContext extends BlockTickContext {
-
-	/*
-	 * Specifications
-	 */
-
-	RelFace getFace();
-
-	/*
-	 * Getters
-	 */
-
-	default TileLogicStackRO getTLSOrNull() {
-		DefaultChunkLogic chunkLogic = getChunkLogic();
-		if (chunkLogic == null)
-			return null;
-
-		return chunkLogic.getTilesOrNull(getBlockInChunk(), getFace());
-	}
-
-	default TileLogicStackRO getTLS() {
-		return getChunkLogic().getTiles(getBlockInChunk(), getFace());
-	}
-
-	default TileDataStack getTDSOrNull() {
-		DefaultChunkData chunkData = getChunkData();
-		if (chunkData == null)
-			return null;
-
-		return chunkData.getTilesOrNull(getBlockInChunk(), getFace());
-	}
-
-	default TileDataStack getTDS() {
-		return getChunkData().getTiles(getBlockInChunk(), getFace());
-	}
-
-	/*
-	 * Contexts
-	 */
-
-	default TileTickContext forLayer(int layer) {
-		return TickContextMutable.start().withServer(getServer()).withBlock(getBlockInWorld()).withFace(getFace())
-			.withLayer(layer);
-	}
-
-	default boolean forEachTile(Consumer<TileTickContext> action) {
-		TickContextMutable context = TickContextMutable.uninitialized();
-
-		TileDataStack stack = getTDSOrNull();
-		if (stack == null || stack.isEmpty())
-			return false;
-
-		for (int layer = 0; layer < stack.size(); ++layer) {
-			context.rebuild().withServer(getServer()).withBlock(getBlockInWorld()).withFace(getFace()).withLayer(layer);
-			action.accept(context);
-		}
-
-		return true;
-	}
-
-	default TSTickContext getComplementary() {
-		return TickContextMutable.copyWorld(this)
-			.withBlock(getBlockInWorld().add_(getFace().getVector(getUp())))
-			.withFace(getFace().getCounter())
-			.build();
-	}
-
-	default <R> R evalComplementary(Function<TSTickContext, R> action) {
-		Objects.requireNonNull(action, "action");
-		return action.apply(getComplementary());
-	}
-
-	default void forComplementary(Consumer<TSTickContext> action) {
-		Objects.requireNonNull(action, "action");
-		evalComplementary((Function<TSTickContext, Void>) ctxt -> {
-			action.accept(ctxt);
-			return null;
-		});
-	}
-
-}

src/main/java/ru/windcorp/progressia/server/world/tile/TickableTile.java

@@ -18,12 +18,14 @@
  
 package ru.windcorp.progressia.server.world.tile;
 
+import ru.windcorp.progressia.server.world.context.ServerTileContext;
+import ru.windcorp.progressia.server.world.context.ServerTileContextRO;
 import ru.windcorp.progressia.server.world.ticking.TickingPolicy;
 
 public interface TickableTile {
 
-	void tick(TileTickContext context);
+	void tick(ServerTileContext context);
 
-	TickingPolicy getTickingPolicy(TileTickContext context);
+	TickingPolicy getTickingPolicy(ServerTileContextRO context);
 
 }

src/main/java/ru/windcorp/progressia/server/world/tile/TileLogic.java

@@ -21,6 +21,7 @@ package ru.windcorp.progressia.server.world.tile;
 import ru.windcorp.progressia.common.util.namespaces.Namespaced;
 import ru.windcorp.progressia.common.world.generic.TileGeneric;
 import ru.windcorp.progressia.common.world.rels.RelFace;
+import ru.windcorp.progressia.server.world.context.ServerTileContextRO;
 
 public class TileLogic extends Namespaced implements TileGeneric {
 
@@ -28,7 +29,7 @@ public class TileLogic extends Namespaced implements TileGeneric {
 		super(id);
 	}
 
-	public boolean canOccupyFace(TileTickContext context) {
+	public boolean canOccupyFace(ServerTileContextRO context) {
 		return canOccupyFace(context.getFace());
 	}
 
@@ -36,7 +37,7 @@ public class TileLogic extends Namespaced implements TileGeneric {
 		return true;
 	}
 
-	public boolean isSolid(TileTickContext context) {
+	public boolean isSolid(ServerTileContextRO context) {
 		return isSolid();
 	}
 

src/main/java/ru/windcorp/progressia/server/world/tile/TileTickContext.java

@@ -1,77 +0,0 @@
-/*
- * Progressia
- * Copyright (C)  2020-2021  Wind Corporation 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 ru.windcorp.progressia.server.world.tile;
-
-import ru.windcorp.progressia.common.world.tile.TileData;
-import ru.windcorp.progressia.server.world.TileLogicStackRO;
-import ru.windcorp.progressia.common.world.TileDataStack;
-import ru.windcorp.progressia.common.world.TileDataReference;
-
-public interface TileTickContext extends TSTickContext {
-
-	/*
-	 * Specifications
-	 */
-
-	/**
-	 * Returns the current layer.
-	 * 
-	 * @return the layer that the tile being ticked occupies in the tile stack
-	 */
-	int getLayer();
-
-	/*
-	 * Getters
-	 */
-
-	default TileLogic getTile() {
-		TileLogicStackRO stack = getTLSOrNull();
-		if (stack == null)
-			return null;
-		return stack.get(getLayer());
-	}
-
-	default TileData getTileData() {
-		TileDataStack stack = getTDSOrNull();
-		if (stack == null)
-			return null;
-		return stack.get(getLayer());
-	}
-
-	default TileDataReference getReference() {
-		return getTDS().getReference(getLayer());
-	}
-
-	default int getTag() {
-		return getTDS().getTagByIndex(getLayer());
-	}
-
-	/*
-	 * Contexts
-	 */
-
-	/*
-	 * Convenience methods - changes
-	 */
-
-	default void removeThisTile() {
-		getAccessor().removeTile(getBlockInWorld(), getFace(), getTag());
-	}
-
-}

src/main/java/ru/windcorp/progressia/server/world/tile/UpdateableTile.java

@@ -18,8 +18,10 @@
  
 package ru.windcorp.progressia.server.world.tile;
 
+import ru.windcorp.progressia.server.world.context.ServerTileContext;
+
 public interface UpdateableTile {
 
-	void update(TileTickContext context);
+	void update(ServerTileContext context);
 
 }

src/main/java/ru/windcorp/progressia/test/TestContent.java

@@ -383,7 +383,7 @@ public class TestContent {
 		ru.windcorp.progressia.server.comms.Client client
 	) {
 		Vec3i blockInWorld = ((ControlBreakBlockData) packet.getControl()).getBlockInWorld();
-		server.getWorldAccessor().setBlock(blockInWorld, BlockDataRegistry.getInstance().get("Test:Air"));
+		server.createContext().setBlock(blockInWorld, BlockDataRegistry.getInstance().get("Test:Air"));
 	}
 
 	private static void onBlockPlaceTrigger(ControlData control) {
@@ -403,7 +403,7 @@ public class TestContent {
 		Vec3i blockInWorld = controlData.getBlockInWorld();
 		if (server.getWorld().getData().getChunkByBlock(blockInWorld) == null)
 			return;
-		server.getWorldAccessor().setBlock(blockInWorld, block);
+		server.createContext().setBlock(blockInWorld, block);
 	}
 
 	private static void onTilePlaceTrigger(ControlData control) {
@@ -428,7 +428,7 @@ public class TestContent {
 			return;
 		if (server.getWorld().getData().getTiles(blockInWorld, face).isFull())
 			return;
-		server.getWorldAccessor().addTile(blockInWorld, face, tile);
+		server.createContext().addTile(blockInWorld, face, tile);
 	}
 
 	private static void registerMisc() {

src/main/java/ru/windcorp/progressia/test/TestEntityLogicStatie.java

@@ -19,7 +19,7 @@
 package ru.windcorp.progressia.test;
 
 import ru.windcorp.progressia.common.world.entity.EntityData;
-import ru.windcorp.progressia.server.world.TickContext;
+import ru.windcorp.progressia.server.world.context.ServerWorldContext;
 import ru.windcorp.progressia.server.world.entity.EntityLogic;
 
 public class TestEntityLogicStatie extends EntityLogic {
@@ -29,13 +29,13 @@ public class TestEntityLogicStatie extends EntityLogic {
 	}
 
 	@Override
-	public void tick(EntityData entity, TickContext context) {
+	public void tick(EntityData entity, ServerWorldContext context) {
 		super.tick(entity, context);
 
 		TestEntityDataStatie statie = (TestEntityDataStatie) entity;
 
 		int size = (int) (18 + 6 * Math.sin(entity.getAge()));
-		context.getServer().getWorldAccessor().changeEntity(statie, e -> e.setSizeNow(size));
+		context.changeEntity(statie, e -> e.setSizeNow(size));
 	}
 
 }

src/main/java/ru/windcorp/progressia/test/TestTileLogicGrass.java

@@ -20,11 +20,11 @@ package ru.windcorp.progressia.test;
 
 import ru.windcorp.progressia.common.world.rels.RelFace;
 import ru.windcorp.progressia.server.world.block.BlockLogic;
-import ru.windcorp.progressia.server.world.block.BlockTickContext;
+import ru.windcorp.progressia.server.world.context.ServerTileContext;
+import ru.windcorp.progressia.server.world.context.ServerTileContextRO;
 import ru.windcorp.progressia.server.world.ticking.TickingPolicy;
 import ru.windcorp.progressia.server.world.tile.HangingTileLogic;
 import ru.windcorp.progressia.server.world.tile.TickableTile;
-import ru.windcorp.progressia.server.world.tile.TileTickContext;
 
 public class TestTileLogicGrass extends HangingTileLogic implements TickableTile {
 
@@ -33,7 +33,7 @@ public class TestTileLogicGrass extends HangingTileLogic implements TickableTile
 	}
 
 	@Override
-	public boolean canOccupyFace(TileTickContext context) {
+	public boolean canOccupyFace(ServerTileContextRO context) {
 		return context.getFace() != RelFace.DOWN && super.canOccupyFace(context);
 	}
 
@@ -43,34 +43,31 @@ public class TestTileLogicGrass extends HangingTileLogic implements TickableTile
 	}
 
 	@Override
-	public TickingPolicy getTickingPolicy(TileTickContext context) {
+	public TickingPolicy getTickingPolicy(ServerTileContextRO context) {
 		return TickingPolicy.RANDOM;
 	}
 
 	@Override
-	public void tick(TileTickContext context) {
+	public void tick(ServerTileContext context) {
 		if (!isLocationSuitable(context)) {
 //			context.removeThisTile();
 		}
 	}
 
 	@Override
-	public boolean canBeSquashed(TileTickContext context) {
+	public boolean canBeSquashed(ServerTileContextRO context) {
 		return true;
 	}
 
-	private boolean isLocationSuitable(TileTickContext context) {
+	private boolean isLocationSuitable(ServerTileContextRO context) {
 		return canOccupyFace(context) && isBlockAboveTransparent(context);
 	}
 
-	private boolean isBlockAboveTransparent(BlockTickContext context) {
+	private boolean isBlockAboveTransparent(ServerTileContextRO context) {
-		return context.evalNeighbor(RelFace.UP, bctxt -> {
+		// TODO rework
-			BlockLogic block = bctxt.getBlock();
+		context.pushRelative(RelFace.UP.resolve(context.getServer().getWorld().getUp(context.getLocation())));
-			if (block == null)
+		BlockLogic block = context.logic().getBlock();
-				return true;
+		return context.popAndReturn(block == null || block.isTransparent(context));
-
-			return block.isTransparent(bctxt);
-		});
 	}
 
 }