world of fluidtanks

src/main/java/com/simibubi/create/api/connectivity/ConnectivityHandler.java

@@ -0,0 +1,372 @@
+package com.simibubi.create.api.connectivity;
+
+import com.simibubi.create.content.contraptions.fluids.tank.CreativeFluidTankTileEntity;
+import com.simibubi.create.foundation.tileEntity.IMultiTileContainer;
+
+import com.simibubi.create.foundation.utility.Iterate;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.entity.BlockEntityType;
+
+import net.minecraftforge.fluids.FluidStack;
+import net.minecraftforge.fluids.IFluidTank;
+import net.minecraftforge.fluids.capability.CapabilityFluidHandler;
+
+import net.minecraftforge.fluids.capability.IFluidHandler;
+
+import net.minecraftforge.items.CapabilityItemHandler;
+
+import org.apache.commons.lang3.tuple.Pair;
+
+import javax.annotation.Nullable;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.PriorityQueue;
+import java.util.Set;
+
+public class ConnectivityHandler {
+
+	public static <T extends BlockEntity & IMultiTileContainer> void formMulti (T be) {
+		SearchCache<T> cache = new SearchCache<>();
+		List<T> frontier = new ArrayList<>();
+		frontier.add(be);
+		formMulti(be.getType(), be.getLevel(), cache, frontier);
+	}
+
+	private static <T extends BlockEntity & IMultiTileContainer> void formMulti (BlockEntityType<?> type, BlockGetter level, SearchCache<T> cache, List<T> frontier) {
+		PriorityQueue<Pair<Integer, T>> creationQueue = makeCreationQueue();
+		Set<BlockPos> visited = new HashSet<>();
+		Direction.Axis mainAxis = frontier.get(0).getMainConnectionAxis();
+
+		// essentially, if it's a vertical multi then the search won't be restricted by Y
+		// alternately, a horizontal multi search shouldn't be restricted by X or Z
+		int minX = (mainAxis == Direction.Axis.Y ? Integer.MAX_VALUE : Integer.MIN_VALUE);
+		int minY = (mainAxis != Direction.Axis.Y ? Integer.MAX_VALUE : Integer.MIN_VALUE);
+		int minZ = (mainAxis == Direction.Axis.Y ? Integer.MAX_VALUE : Integer.MIN_VALUE);
+
+		for (T be : frontier) {
+			BlockPos pos = be.getBlockPos();
+			minX = Math.min(pos.getX(), minX);
+			minY = Math.min(pos.getY(), minY);
+			minZ = Math.min(pos.getZ(), minZ);
+		}
+		if (mainAxis == Direction.Axis.Y) minX -= frontier.get(0).getMaxWidth();
+		if (mainAxis != Direction.Axis.Y) minY -= frontier.get(0).getMaxWidth();
+		if (mainAxis == Direction.Axis.Y) minZ -= frontier.get(0).getMaxWidth();
+
+		while (!frontier.isEmpty()) {
+			T part = frontier.remove(0);
+			BlockPos partPos = part.getBlockPos();
+			if (visited.contains(partPos)) continue;
+
+			visited.add(partPos);
+
+			int amount = tryToFormNewMulti(part, cache, true);
+			if (amount > 1) {
+				creationQueue.add(Pair.of(amount, part));
+			}
+
+			for (Direction.Axis axis : Iterate.axes) {
+				Direction dir = Direction.get(Direction.AxisDirection.NEGATIVE, axis);
+				BlockPos next = partPos.relative(dir);
+
+				if (next.getX() <= minX || next.getY() <= minY || next.getZ() <= minZ) continue;
+				if (visited.contains(next)) continue;
+				T nextBe = partAt(type, level, next);
+				if (nextBe == null) continue;
+				if (nextBe.isRemoved()) continue;
+				frontier.add(nextBe);
+			}
+		}
+		visited.clear();
+
+		while (!creationQueue.isEmpty()) {
+			Pair<Integer, T> next = creationQueue.poll();
+			T toCreate = next.getValue();
+			if (visited.contains(toCreate.getBlockPos())) continue;
+
+			visited.add(toCreate.getBlockPos());
+			tryToFormNewMulti(toCreate, cache, false);
+		}
+	}
+
+	private static <T extends BlockEntity & IMultiTileContainer> int tryToFormNewMulti (T be, SearchCache<T> cache, boolean simulate) {
+		int bestWidth  =  1;
+		int bestAmount = -1;
+		if (!be.isController()) return 0;
+
+		int radius = be.getMaxWidth();
+		for (int w = 1; w <= radius; w++) {
+			int amount = tryToFormNewMultiOfWidth(be, w, cache, true);
+			if (amount < bestAmount) continue;
+			bestWidth = w;
+			bestAmount = amount;
+		}
+
+		if (!simulate) {
+			int beWidth = be.getWidth();
+			if (beWidth == bestWidth && beWidth*beWidth * be.getHeight() == bestAmount) return bestAmount;
+
+			splitMultiAndInvalidate(be, cache, false);
+			if (be.hasFluid()) be.setTankSize(0, bestAmount);
+
+			tryToFormNewMultiOfWidth(be, bestWidth, cache, false);
+
+			be.preventConnectivityUpdate();
+			be.setWidth(bestWidth);
+			be.setHeight(bestAmount / bestWidth / bestWidth);
+			be.notifyMultiUpdated();
+		}
+		return bestAmount;
+	}
+
+	private static <T extends BlockEntity & IMultiTileContainer> int tryToFormNewMultiOfWidth (T be, int width, SearchCache<T> cache, boolean simulate) {
+		int amount = 0;
+		int height = 0;
+		BlockEntityType<?> type = be.getType();
+		Level level = be.getLevel();
+		if (level == null) return 0;
+		BlockPos origin = be.getBlockPos();
+
+		// optional fluid handling
+		IFluidTank beTank = null;
+		FluidStack fluid = FluidStack.EMPTY;
+		if (be.hasFluid()) {
+			beTank = be.getTank(0);
+			fluid  = beTank.getFluid();
+		}
+		Direction.Axis axis = be.getMainConnectionAxis();
+
+		Search:
+		for (int yOffset = 0; yOffset < be.getMaxLength(axis, width); yOffset++) {
+			for (int xOffset = 0; xOffset < width; xOffset++) {
+				for (int zOffset = 0; zOffset < width; zOffset++) {
+					BlockPos pos = switch (axis) {
+						case X -> origin.offset(yOffset, xOffset, zOffset);
+						case Y -> origin.offset(xOffset, yOffset, zOffset);
+						case Z -> origin.offset(xOffset, zOffset, yOffset);
+					};
+					Optional<T> part = cache.getOrCache(type, level, pos);
+					if (part.isEmpty()) break Search;
+
+					T controller = part.get();
+					int otherWidth = controller.getWidth();
+					if (otherWidth > width) break Search;
+					if (otherWidth == width && controller.getHeight() == be.getMaxLength(axis, width)) break Search;
+
+					Direction.Axis conAxis = controller.getMainConnectionAxis();
+					if (axis != conAxis) break Search;
+
+					BlockPos conPos = controller.getBlockPos();
+					if (!conPos.equals(origin)) {
+						if (axis == Direction.Axis.Y) { // vertical multi, like a FluidTank
+							if (conPos.getX() < origin.getX()) break Search;
+							if (conPos.getZ() < origin.getZ()) break Search;
+							if (conPos.getX() + otherWidth > origin.getX() + width) break Search;
+							if (conPos.getZ() + otherWidth > origin.getZ() + width) break Search;
+						} else { // horizontal multi, like an ItemVault
+							if (axis == Direction.Axis.Z && conPos.getX() < origin.getX()) break Search;
+							if (conPos.getY() < origin.getY()) break Search;
+							if (axis == Direction.Axis.X && conPos.getZ() < origin.getZ()) break Search;
+							if (axis == Direction.Axis.Z && conPos.getX() + otherWidth > origin.getX() + width) break Search;
+							if (conPos.getY() + otherWidth > origin.getY() + width) break Search;
+							if (axis == Direction.Axis.X && conPos.getZ() + otherWidth > origin.getZ() + width) break Search;
+						}
+					}
+					FluidStack otherFluid = controller.getFluid(0);
+					if (!fluid.isEmpty() && !otherFluid.isEmpty() && !fluid.isFluidEqual(otherFluid)) break Search;
+				}
+			}
+			amount += width * width;
+			height++;
+		}
+
+		if (simulate) return amount;
+
+		Object extraData = be.getExtraData();
+
+		for (int yOffset = 0; yOffset < height; yOffset++) {
+			for (int xOffset = 0; xOffset < width; xOffset++) {
+				for (int zOffset = 0; zOffset < width; zOffset++) {
+					BlockPos pos = switch (axis) {
+						case X -> origin.offset(yOffset, xOffset, zOffset);
+						case Y -> origin.offset(xOffset, yOffset, zOffset);
+						case Z -> origin.offset(xOffset, zOffset, yOffset);
+					};
+					T part = partAt(type, level, pos);
+					if (part == null) continue;
+					if (part == be) continue;
+
+					extraData = be.modifyExtraData(extraData);
+
+					if (part.hasFluid()) {
+						IFluidTank tankAt  = part.getTank(0);
+						FluidStack fluidAt = tankAt.getFluid();
+						if (!fluidAt.isEmpty()) {
+							// making this generic would be a rather large mess, unfortunately
+							if (beTank != null && fluid.isEmpty() && beTank instanceof CreativeFluidTankTileEntity.CreativeSmartFluidTank) {
+								((CreativeFluidTankTileEntity.CreativeSmartFluidTank)beTank).setContainedFluid(fluidAt);
+							}
+						}
+						tankAt.drain(tankAt.getCapacity(), IFluidHandler.FluidAction.EXECUTE);
+					}
+
+					splitMultiAndInvalidate(part, cache, false);
+					part.setController(origin);
+					part.preventConnectivityUpdate();
+					cache.put(pos, be);
+					part.setHeight(height);
+					part.notifyMultiUpdated();
+				}
+			}
+		}
+		be.setExtraData(extraData);
+		be.notifyMultiUpdated();
+		return amount;
+	}
+
+	public static <T extends BlockEntity & IMultiTileContainer> void splitMulti (T be) {
+		splitMultiAndInvalidate(be, null, false);
+	}
+
+	// tryReconnect helps whenever only a few tanks have been removed
+	private static <T extends BlockEntity & IMultiTileContainer> void splitMultiAndInvalidate (T be, @Nullable SearchCache<T> cache, boolean tryReconnect) {
+		Level level = be.getLevel();
+		if (level == null) return;
+
+		be = be.getControllerTE();
+		if (be == null) return;
+
+		int height = be.getHeight();
+		int width  = be.getWidth();
+		if (width == 1 && height == 1) return;
+
+		BlockPos origin  = be.getBlockPos();
+		List<T> frontier = new ArrayList<>();
+		Direction.Axis axis = be.getMainConnectionAxis();
+
+		// fluid handling, if present
+		FluidStack toDistribute = FluidStack.EMPTY;
+		int maxCapacity = 0;
+		if (be.hasFluid()) {
+			toDistribute = be.getFluid(0);
+			maxCapacity  = be.getTankSize(0);
+			if (!toDistribute.isEmpty() && !be.isRemoved()) toDistribute.shrink(maxCapacity);
+			be.setTankSize(0, 1);
+		}
+
+		for (int yOffset = 0; yOffset < height; yOffset++) {
+			for (int xOffset = 0; xOffset < width; xOffset++) {
+				for (int zOffset = 0; zOffset < width; zOffset++) {
+					BlockPos pos = switch (axis) {
+						case X -> origin.offset(yOffset, xOffset, zOffset);
+						case Y -> origin.offset(xOffset, yOffset, zOffset);
+						case Z -> origin.offset(xOffset, zOffset, yOffset);
+					};
+					T partAt = partAt(be.getType(), level, pos);
+					if (partAt == null) continue;
+					if (!partAt.getController().equals(origin)) continue;
+
+					T controllerBE = partAt.getControllerTE();
+					partAt.setExtraData ( (controllerBE == null ? null : controllerBE.getExtraData()));
+					partAt.removeController(true);
+
+					if (!toDistribute.isEmpty() && partAt != be) {
+						FluidStack copy = toDistribute.copy();
+						IFluidTank tank = partAt.getTank(0);
+						// making this generic would be a rather large mess, unfortunately
+						if (tank instanceof CreativeFluidTankTileEntity.CreativeSmartFluidTank creativeTank) {
+							if (creativeTank.isEmpty()) creativeTank.setContainedFluid(toDistribute);
+						}
+						else {
+							int split = Math.min(maxCapacity, toDistribute.getAmount());
+							copy.setAmount(split);
+							toDistribute.shrink(split);
+							tank.fill(copy, IFluidHandler.FluidAction.EXECUTE);
+						}
+					}
+					if (tryReconnect) {
+						frontier.add(partAt);
+						partAt.preventConnectivityUpdate();
+					}
+					if (cache != null) {
+						cache.put(pos, partAt);
+					}
+				}
+			}
+		}
+		if (be.hasItems()) {
+			be.getCapability(CapabilityItemHandler.ITEM_HANDLER_CAPABILITY).invalidate();
+		}
+		if (be.hasFluid()) {
+			be.getCapability(CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY).invalidate();
+		}
+		if (tryReconnect) {
+			formMulti(be.getType(), level, cache == null ? new SearchCache<>() : cache, frontier);
+		}
+	}
+
+	private static <T extends BlockEntity & IMultiTileContainer> PriorityQueue<Pair<Integer, T>> makeCreationQueue () {
+		return new PriorityQueue<>((one, two) -> two.getKey() - one.getKey());
+	}
+
+	@Nullable
+	public static <T extends BlockEntity & IMultiTileContainer> T partAt (BlockEntityType<?> type, BlockGetter level, BlockPos pos) {
+		BlockEntity be = level.getBlockEntity(pos);
+		if (be != null && be.getType() == type) return checked(be);
+
+		return null;
+	}
+
+	public static <T extends BlockEntity & IMultiTileContainer> boolean isConnected (BlockGetter level, BlockPos pos, BlockPos other) {
+		T one = checked(level.getBlockEntity(pos));
+		T two = checked(level.getBlockEntity(other));
+		if (one == null || two == null) return false;
+		return one.getController().equals(two.getController());
+	}
+
+	@Nullable
+	@SuppressWarnings("unchecked")
+	private static <T extends BlockEntity & IMultiTileContainer> T checked (BlockEntity be) {
+		if (be instanceof IMultiTileContainer) return (T)be;
+		return null;
+	}
+
+	private static class SearchCache<T extends BlockEntity & IMultiTileContainer> {
+		Map<BlockPos, Optional<T>> controllerMap;
+
+		public SearchCache () { controllerMap = new HashMap<>(); }
+
+		void put (BlockPos pos, T target) { controllerMap.put(pos, Optional.of(target)); }
+
+		void putEmpty (BlockPos pos) { controllerMap.put(pos, Optional.empty()); }
+
+		boolean hasVisited (BlockPos pos) { return controllerMap.containsKey(pos); }
+
+		Optional<T> getOrCache (BlockEntityType<?> type, BlockGetter level, BlockPos pos) {
+			if (hasVisited(pos)) return controllerMap.get(pos);
+
+			T partAt = partAt(type, level, pos);
+			if (partAt == null) {
+				putEmpty(pos);
+				return Optional.empty();
+			}
+			T controller = checked(level.getBlockEntity(partAt.getController()));
+			if (controller == null) {
+				putEmpty(pos);
+				return Optional.empty();
+			}
+			put(pos, controller);
+			return Optional.of(controller);
+		}
+	}
+}

src/main/java/com/simibubi/create/content/contraptions/components/structureMovement/BlockMovementChecks.java

@@ -5,6 +5,7 @@ import java.util.List;
 
 import com.simibubi.create.AllBlocks;
 import com.simibubi.create.AllTags.AllBlockTags;
+import com.simibubi.create.api.connectivity.ConnectivityHandler;
 import com.simibubi.create.content.contraptions.components.actors.AttachedActorBlock;
 import com.simibubi.create.content.contraptions.components.actors.HarvesterBlock;
 import com.simibubi.create.content.contraptions.components.actors.PloughBlock;
@@ -330,7 +331,7 @@ public class BlockMovementChecks {
 			return direction.getAxis() != state.getValue(SailBlock.FACING)
 					.getAxis();
 		if (state.getBlock() instanceof FluidTankBlock)
-			return FluidTankConnectivityHandler.isConnected(world, pos, pos.relative(direction));
+			return ConnectivityHandler.isConnected(world, pos, pos.relative(direction)); //FluidTankConnectivityHandler.isConnected(world, pos, pos.relative(direction));
 		if (state.getBlock() instanceof ItemVaultBlock)
 			return ItemVaultConnectivityHandler.isConnected(world, pos, pos.relative(direction));
 		if (AllBlocks.STICKER.has(state) && state.getValue(StickerBlock.EXTENDED)) {
@@ -349,7 +350,7 @@ public class BlockMovementChecks {
 			return state.getValue(HarvesterBlock.FACING) == facing;
 		if (AllBlocks.MECHANICAL_PLOUGH.has(state))
 			return state.getValue(PloughBlock.FACING) == facing;
-		
+
 		if (AllBlocks.CART_ASSEMBLER.has(state))
 			return Direction.DOWN == facing;
 		if (AllBlocks.MECHANICAL_SAW.has(state))

src/main/java/com/simibubi/create/content/contraptions/fluids/tank/FluidTankBlock.java

@@ -1,6 +1,7 @@
 package com.simibubi.create.content.contraptions.fluids.tank;
 
 import com.simibubi.create.AllTileEntities;
+import com.simibubi.create.api.connectivity.ConnectivityHandler;
 import com.simibubi.create.content.contraptions.fluids.actors.GenericItemFilling;
 import com.simibubi.create.content.contraptions.fluids.tank.CreativeFluidTankTileEntity.CreativeSmartFluidTank;
 import com.simibubi.create.content.contraptions.processing.EmptyingByBasin;
@@ -90,10 +91,10 @@ public class FluidTankBlock extends Block implements IWrenchable, ITE<FluidTankT
 	protected void createBlockStateDefinition(Builder<Block, BlockState> p_206840_1_) {
 		p_206840_1_.add(TOP, BOTTOM, SHAPE);
 	}
-	
+
 	@Override
 	public int getLightEmission(BlockState state, BlockGetter world, BlockPos pos) {
-		FluidTankTileEntity tankAt = FluidTankConnectivityHandler.anyTankAt(world, pos);
+		FluidTankTileEntity tankAt = ConnectivityHandler.partAt(getTileEntityType(), world, pos); //FluidTankConnectivityHandler.anyTankAt(world, pos);
 		if (tankAt == null)
 			return 0;
 		FluidTankTileEntity controllerTE = tankAt.getControllerTE();
@@ -120,7 +121,7 @@ public class FluidTankBlock extends Block implements IWrenchable, ITE<FluidTankT
 			return InteractionResult.PASS;
 
 		FluidExchange exchange = null;
-		FluidTankTileEntity te = FluidTankConnectivityHandler.anyTankAt(world, pos);
+		FluidTankTileEntity te = ConnectivityHandler.partAt(getTileEntityType(), world, pos); //FluidTankConnectivityHandler.anyTankAt(world, pos);
 		if (te == null)
 			return InteractionResult.FAIL;
 
@@ -231,7 +232,8 @@ public class FluidTankBlock extends Block implements IWrenchable, ITE<FluidTankT
 				return;
 			FluidTankTileEntity tankTE = (FluidTankTileEntity) te;
 			world.removeBlockEntity(pos);
-			FluidTankConnectivityHandler.splitTank(tankTE);
+			//FluidTankConnectivityHandler.splitTank(tankTE);
+			ConnectivityHandler.splitMulti(tankTE);
 		}
 	}
 
@@ -239,7 +241,7 @@ public class FluidTankBlock extends Block implements IWrenchable, ITE<FluidTankT
 	public Class<FluidTankTileEntity> getTileEntityClass() {
 		return FluidTankTileEntity.class;
 	}
-	
+
 	@Override
 	public BlockEntityType<? extends FluidTankTileEntity> getTileEntityType() {
 		return creative ? AllTileEntities.CREATIVE_FLUID_TANK.get() : AllTileEntities.FLUID_TANK.get();

src/main/java/com/simibubi/create/content/contraptions/fluids/tank/FluidTankCTBehaviour.java

@@ -1,5 +1,6 @@
 package com.simibubi.create.content.contraptions.fluids.tank;
 
+import com.simibubi.create.api.connectivity.ConnectivityHandler;
 import com.simibubi.create.foundation.block.connected.CTSpriteShiftEntry;
 import com.simibubi.create.foundation.block.connected.HorizontalCTBehaviour;
 
@@ -21,6 +22,6 @@ public class FluidTankCTBehaviour extends HorizontalCTBehaviour {
 	@Override
 	public boolean connectsTo(BlockState state, BlockState other, BlockAndTintGetter reader, BlockPos pos, BlockPos otherPos,
 		Direction face) {
-		return state.getBlock() == other.getBlock() && FluidTankConnectivityHandler.isConnected(reader, pos, otherPos);
+		return state.getBlock() == other.getBlock() && ConnectivityHandler.isConnected(reader, pos, otherPos); //FluidTankConnectivityHandler.isConnected(reader, pos, otherPos);
 	}
 }

src/main/java/com/simibubi/create/content/contraptions/fluids/tank/FluidTankItem.java

@@ -1,5 +1,8 @@
 package com.simibubi.create.content.contraptions.fluids.tank;
 
+import com.simibubi.create.AllTileEntities;
+import com.simibubi.create.api.connectivity.ConnectivityHandler;
+
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
@@ -71,7 +74,7 @@ public class FluidTankItem extends BlockItem {
 
 		if (!FluidTankBlock.isTank(placedOnState))
 			return;
-		FluidTankTileEntity tankAt = FluidTankConnectivityHandler.anyTankAt(world, placedOnPos);
+		FluidTankTileEntity tankAt = ConnectivityHandler.partAt(AllTileEntities.FLUID_TANK.get(), world, placedOnPos); //FluidTankConnectivityHandler.anyTankAt(world, placedOnPos);
 		if (tankAt == null)
 			return;
 		FluidTankTileEntity controllerTE = tankAt.getControllerTE();

src/main/java/com/simibubi/create/content/contraptions/fluids/tank/FluidTankModel.java

@@ -7,6 +7,7 @@ import java.util.List;
 import java.util.Random;
 
 import com.simibubi.create.AllSpriteShifts;
+import com.simibubi.create.api.connectivity.ConnectivityHandler;
 import com.simibubi.create.foundation.block.connected.CTModel;
 import com.simibubi.create.foundation.block.connected.CTSpriteShiftEntry;
 import com.simibubi.create.foundation.utility.Iterate;
@@ -28,20 +29,20 @@ public class FluidTankModel extends CTModel {
 	public static FluidTankModel standard(BakedModel originalModel) {
 		return new FluidTankModel(originalModel, AllSpriteShifts.FLUID_TANK, AllSpriteShifts.COPPER_CASING);
 	}
-	
+
 	public static FluidTankModel creative(BakedModel originalModel) {
 		return new FluidTankModel(originalModel, AllSpriteShifts.CREATIVE_FLUID_TANK, AllSpriteShifts.CREATIVE_CASING);
 	}
-	
+
 	private FluidTankModel(BakedModel originalModel, CTSpriteShiftEntry side, CTSpriteShiftEntry top) {
 		super(originalModel, new FluidTankCTBehaviour(side, top));
 	}
-	
+
 	@Override
 	protected Builder gatherModelData(Builder builder, BlockAndTintGetter world, BlockPos pos, BlockState state) {
 		CullData cullData = new CullData();
 		for (Direction d : Iterate.horizontalDirections)
-			cullData.setCulled(d, FluidTankConnectivityHandler.isConnected(world, pos, pos.relative(d)));
+			cullData.setCulled(d, ConnectivityHandler.isConnected(world, pos, pos.relative(d))); //FluidTankConnectivityHandler.isConnected(world, pos, pos.relative(d)));
 		return super.gatherModelData(builder, world, pos, state).withInitial(CULL_PROPERTY, cullData);
 	}
 

src/main/java/com/simibubi/create/content/contraptions/fluids/tank/FluidTankTileEntity.java

@@ -7,6 +7,8 @@ import java.util.List;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import com.simibubi.create.Create;
+import com.simibubi.create.api.connectivity.ConnectivityHandler;
 import com.simibubi.create.content.contraptions.fluids.tank.FluidTankBlock.Shape;
 import com.simibubi.create.content.contraptions.goggles.IHaveGoggleInformation;
 import com.simibubi.create.foundation.config.AllConfigs;
@@ -79,7 +81,8 @@ public class FluidTankTileEntity extends SmartTileEntity implements IHaveGoggleI
 			return;
 		if (!isController())
 			return;
-		FluidTankConnectivityHandler.formTanks(this);
+		//FluidTankConnectivityHandler.formTanks(this);
+		ConnectivityHandler.formMulti(this);
 	}
 
 	@Override
@@ -103,7 +106,7 @@ public class FluidTankTileEntity extends SmartTileEntity implements IHaveGoggleI
 		if (fluidLevel != null)
 			fluidLevel.tick();
 	}
-	
+
 	@Override
 	public BlockPos getLastKnownPos() {
 		return lastKnownPos;
@@ -145,7 +148,7 @@ public class FluidTankTileEntity extends SmartTileEntity implements IHaveGoggleI
 			for (int xOffset = 0; xOffset < width; xOffset++) {
 				for (int zOffset = 0; zOffset < width; zOffset++) {
 					BlockPos pos = this.worldPosition.offset(xOffset, yOffset, zOffset);
-					FluidTankTileEntity tankAt = FluidTankConnectivityHandler.anyTankAt(level, pos);
+					FluidTankTileEntity tankAt = ConnectivityHandler.partAt(getType(), level, pos); //FluidTankConnectivityHandler.anyTankAt(level, pos);
 					if (tankAt == null)
 						continue;
 					level.updateNeighbourForOutputSignal(pos, tankAt.getBlockState()
@@ -161,7 +164,7 @@ public class FluidTankTileEntity extends SmartTileEntity implements IHaveGoggleI
 			setChanged();
 			sendData();
 		}
-		
+
 		if (isVirtual()) {
 			if (fluidLevel == null)
 				fluidLevel = new InterpolatedChasingValue().start(getFillState());
@@ -462,4 +465,82 @@ public class FluidTankTileEntity extends SmartTileEntity implements IHaveGoggleI
 		this.fluidLevel = fluidLevel;
 	}
 
+	@Override
+	public void preventConnectivityUpdate() { updateConnectivity = false; }
+
+	@Override
+	public void notifyMultiUpdated () {
+		BlockState state = this.getBlockState();
+		if (FluidTankBlock.isTank(state)) { // safety
+			state = state.setValue(FluidTankBlock.BOTTOM, getController().getY() == getBlockPos().getY());
+			state = state.setValue(FluidTankBlock.TOP, getController().getY() + height - 1 == getBlockPos().getY());
+			level.setBlock(getBlockPos(), state, 22);
+		}
+		setWindows(window);
+		onFluidStackChanged(tankInventory.getFluid());
+		setChanged();
+	}
+
+	@Override
+	public void setExtraData (@Nullable Object data) {
+		if (data instanceof Boolean) window = (boolean)data;
+	}
+
+	@Override
+	@Nullable
+	public Object getExtraData () { return window; }
+
+	@Override
+	public Object modifyExtraData (Object data) {
+		if (data instanceof Boolean windows) {
+			windows |= window;
+			return windows;
+		}
+		return data;
+	}
+
+	@Override
+	public Direction.Axis getMainConnectionAxis() { return Direction.Axis.Y; }
+
+	@Override
+	public int getMaxLength (Direction.Axis longAxis, int width) {
+		if (longAxis == Direction.Axis.Y) return getMaxHeight();
+		return getMaxWidth();
+	}
+
+	@Override
+	public int getMaxWidth () { return MAX_SIZE; }
+
+	@Override
+	public int getHeight () { return height; }
+
+	@Override
+	public void setHeight (int height) { this.height = height; }
+
+	@Override
+	public int getWidth () { return width; }
+
+	@Override
+	public void setWidth (int width) { this.width = width; }
+
+	@Override
+	public boolean hasFluid () { return true; }
+
+	@Override
+	public int getTankSize (int tank) { return getCapacityMultiplier(); }
+
+	@Override
+	public void setTankSize (int tank, int blocks) {
+		applyFluidTankSize(blocks);
+	}
+
+	@Override
+	public IFluidTank getTank (int tank) {
+		return tankInventory;
+	}
+
+	@Override
+	public FluidStack getFluid (int tank) {
+		return tankInventory.getFluid().copy();
+	}
 }

src/main/java/com/simibubi/create/foundation/tileEntity/IMultiTileContainer.java

@@ -1,12 +1,69 @@
 package com.simibubi.create.foundation.tileEntity;
 
 import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.block.state.properties.BlockStateProperties;
+import net.minecraftforge.fluids.FluidStack;
+import net.minecraftforge.fluids.IFluidTank;
+
+import javax.annotation.Nullable;
 
 public interface IMultiTileContainer {
-	
-	public BlockPos getController();
-	public boolean isController();
-	public void setController(BlockPos pos);
-	public BlockPos getLastKnownPos();
 
+	BlockPos getController();
+	<T extends BlockEntity & IMultiTileContainer> T getControllerTE ();
+	boolean isController();
+	void setController(BlockPos pos);
+	void removeController (boolean keepContents);
+	BlockPos getLastKnownPos();
+
+	void preventConnectivityUpdate ();
+	void notifyMultiUpdated ();
+
+	// only used for FluidTank windows at present. Might be useful for similar properties on other things?
+	default void setExtraData (@Nullable Object data) {}
+	@Nullable
+	default Object getExtraData () { return null; }
+	default Object modifyExtraData (Object data) { return data; }
+
+	// multiblock structural information
+	Direction.Axis getMainConnectionAxis();
+	default Direction.Axis getMainAxisOf (BlockEntity be) { // this feels redundant, but it gives us a default to use when defining ::getMainConnectionAxis
+		BlockState state = be.getBlockState();
+
+		Direction.Axis axis;
+		if (state.hasProperty(BlockStateProperties.HORIZONTAL_AXIS)) {
+			axis = state.getValue(BlockStateProperties.HORIZONTAL_AXIS);
+		}
+		else if (state.hasProperty(BlockStateProperties.FACING)) {
+			axis = state.getValue(BlockStateProperties.FACING).getAxis();
+		}
+		else if (state.hasProperty(BlockStateProperties.HORIZONTAL_FACING)) {
+			axis = state.getValue(BlockStateProperties.HORIZONTAL_FACING).getAxis();
+		}
+		else axis = Direction.Axis.Y;
+
+		return axis;
+	}
+
+	int getMaxLength (Direction.Axis longAxis, int width);
+	int getMaxWidth  ();
+
+	int getHeight ();
+	void setHeight (int height);
+	int getWidth  ();
+	void setWidth  (int width);
+
+	// optional item handling
+	default boolean hasItems () { return false; }
+
+	// optional fluid handling
+	// done here rather than through the Capability to allow greater flexibility
+	default boolean hasFluid () { return false; }
+	default int getTankSize  (int tank) { return 0; }
+	default void setTankSize (int tank, int blocks) {}
+	default IFluidTank getTank  (int tank) { return null; }
+	default FluidStack getFluid (int tank) { return FluidStack.EMPTY; }
 }