Progress on Maze Generation

* Finished implementing link planning for mazes. Doors aren't placed yet
because that's up to Decorators and those haven't been implemented yet.
* Added bounding walls to mazes.
* Added decay effects to mazes.

src/main/java/StevenDimDoors/experimental/LinkPlan.java

@@ -1,52 +1,47 @@
 package StevenDimDoors.experimental;
 
+import StevenDimDoors.mod_pocketDim.Point3D;
+
 public class LinkPlan
 {
 	private RoomData source;
 	private RoomData destination;
-	private boolean entrance;
+	private Point3D sourcePoint;
+	private Point3D destinationPoint;
+	private final boolean entrance;
+	private final boolean internal;
 	
-	private LinkPlan(RoomData source, RoomData destination, boolean entrance)
-	{
-		this.source = source;
-		this.destination = destination;
-		this.entrance = entrance;
-	}
-	
-	public static LinkPlan createInternalLink(RoomData source, RoomData destination)
+	private LinkPlan(RoomData source, boolean entrance, boolean internal)
 	{
 		if (source == null)
 		{
 			throw new IllegalArgumentException("source cannot be null.");
 		}
-		if (destination == null)
-		{
-			throw new IllegalArgumentException("destination cannot be null.");
-		}
-		LinkPlan plan = new LinkPlan(source, destination, false);
+		this.source = source;
+		this.destination = null;
+		this.sourcePoint = null;
+		this.destinationPoint = null;
+		this.entrance = entrance;
+		this.internal = internal;
+	}
+	
+	public static LinkPlan createInternalLink(RoomData source)
+	{
+		LinkPlan plan = new LinkPlan(source, false, true);
 		source.getOutboundLinks().add(plan);
-		destination.getInboundLinks().add(plan);
 		return plan;
 	}
 	
 	public static LinkPlan createEntranceLink(RoomData source)
 	{
-		if (source == null)
-		{
-			throw new IllegalArgumentException("source cannot be null.");
-		}
-		LinkPlan plan = new LinkPlan(source, null, true);
+		LinkPlan plan = new LinkPlan(source, true, false);
 		source.getOutboundLinks().add(plan);
 		return plan;
 	}
 	
 	public static LinkPlan createDungeonLink(RoomData source)
 	{
-		if (source == null)
-		{
-			throw new IllegalArgumentException("source cannot be null.");
-		}
-		LinkPlan plan = new LinkPlan(source, null, false);
+		LinkPlan plan = new LinkPlan(source, false, false);
 		source.getOutboundLinks().add(plan);
 		return plan;
 	}
@@ -68,7 +63,7 @@ public class LinkPlan
 	
 	public boolean isInternal()
 	{
-		return (destination != null);
+		return internal;
 	}
 	
 	public void remove()
@@ -84,4 +79,42 @@ public class LinkPlan
 			destination = null;
 		}
 	}
+
+	public void setDestination(RoomData destination)
+	{
+		if (!internal)
+		{
+			throw new IllegalStateException("LinkPlan.setDestination() is only applicable to internal links.");
+		}
+		if (this.destination != null)
+		{
+			throw new IllegalStateException("destination can only be set once.");
+		}
+		if (destination == null)
+		{
+			throw new IllegalArgumentException("destination cannot be null.");
+		}
+		this.destination = destination;
+		destination.getInboundLinks().add(this);
+	}
+	
+	public Point3D sourcePoint()
+	{
+		return this.sourcePoint;
+	}
+	
+	public Point3D destinationPoint()
+	{
+		return this.destinationPoint;
+	}
+	
+	public void setSourcePoint(Point3D value)
+	{
+		this.sourcePoint = value;
+	}
+	
+	public void setDestinationPoint(Point3D value)
+	{
+		this.destinationPoint = value;
+	}
 }

src/main/java/StevenDimDoors/experimental/MazeBuilder.java

@@ -1,18 +1,23 @@
 package StevenDimDoors.experimental;
 
+import java.util.ArrayList;
 import java.util.Random;
+import java.util.Stack;
 
 import net.minecraft.block.Block;
 import net.minecraft.world.World;
 import net.minecraft.world.chunk.Chunk;
 import net.minecraft.world.chunk.storage.ExtendedBlockStorage;
 import StevenDimDoors.mod_pocketDim.Point3D;
+import StevenDimDoors.mod_pocketDim.config.DDProperties;
 
 public class MazeBuilder
 {
+	private static final int POCKET_WALL_GAP = 4;
+	
 	private MazeBuilder() { }
 	
-	public static void generate(World world, int x, int y, int z, Random random)
+	public static void generate(World world, int x, int y, int z, Random random, DDProperties properties)
 	{
 		// ISSUE FOR LATER: The room needs to be shifted so as to be centered on its entrance
 		
@@ -22,16 +27,85 @@ public class MazeBuilder
 		
 		buildRooms(design.getLayout(), world, offset);
 		carveDoorways(design.getLayout(), world, offset, decay, random);
-		
-		placeDoors(design.getLayout(), world, offset);
-		
 		applyRandomDestruction(design, world, offset, decay, random);
+		decorateRooms(design.getLayout(), world, offset);
+		buildPocketWalls(design, world, offset, properties);
 	}
 	
 	private static void applyRandomDestruction(MazeDesign design, World world,
 			Point3D offset, SphereDecayOperation decay, Random random)
 	{
-		//final int DECAY_BOX_SIZE = 8  
+		final int DECAY_BOX_SIZE = 7;
+		final int DECAY_OPERATIONS = 5 + random.nextInt(5);
+		final int DECAY_ATTEMPTS = 20;
+		
+		int x, y, z;
+		int successes = 0;
+		int attempts = 0;
+		PartitionNode root = design.getRootPartition();
+		
+		for (; successes < DECAY_OPERATIONS && attempts < DECAY_ATTEMPTS; attempts++)
+		{
+			// Select the coordinates at which to apply the decay operation
+			x = random.nextInt(design.width()) - DECAY_BOX_SIZE / 2;
+			y = random.nextInt(design.height()) - DECAY_BOX_SIZE / 2;
+			z = random.nextInt(design.length()) - DECAY_BOX_SIZE / 2;
+			
+			// Check that the decay operation would not impact any protected areas
+			// and mark the affected areas as decayed
+			if (markDecayArea(x, y, z, DECAY_BOX_SIZE, root))
+			{
+				// Apply decay
+				decay.apply(world, offset.getX() + x, offset.getY() + y, offset.getZ() + z,
+						DECAY_BOX_SIZE, DECAY_BOX_SIZE, DECAY_BOX_SIZE);
+				successes++;
+			}
+		}
+	}
+	
+	private static boolean markDecayArea(int x, int y, int z, int DECAY_BOX_SIZE, PartitionNode<RoomData> root)
+	{
+		// Check if a given PartitionNode intersects the decay area. If it's a leaf, then check
+		// if it's protected or not. Otherwise, check its children. The specific area is valid
+		// if and only if there are no protected rooms and at least one (unprotected) room in it.
+		// Also list the unprotected rooms to mark them if the decay operation will proceed.
+		
+		RoomData room;
+		PartitionNode<RoomData> partition;
+		ArrayList<RoomData> targets = new ArrayList<RoomData>();
+		Stack<PartitionNode<RoomData>> nodes = new Stack<PartitionNode<RoomData>>();
+		BoundingBox decayBounds = new BoundingBox(x, y, z, DECAY_BOX_SIZE, DECAY_BOX_SIZE, DECAY_BOX_SIZE);
+		
+		// Use depth-first search to explore all intersecting partitions
+		nodes.push(root);
+		while (!nodes.isEmpty())
+		{
+			partition = nodes.pop();
+			if (decayBounds.intersects(partition))
+			{
+				if (partition.isLeaf())
+				{
+					room = partition.getData();
+					if (room.isProtected())
+						return false;
+					targets.add(room);
+				}
+				else
+				{
+					if (partition.leftChild() != null)
+						nodes.push(partition.leftChild());
+					if (partition.rightChild() != null)
+						nodes.push(partition.rightChild());
+				}
+			}
+		}
+		// If execution has reached this point, then there were no protected rooms.
+		// Mark all intersecting rooms as decayed.
+		for (RoomData target : targets)
+		{
+			target.setDecayed(true);
+		}
+		return !targets.isEmpty();
 	}
 
 	private static void buildRooms(DirectedGraph<RoomData, DoorwayData> layout, World world, Point3D offset)
@@ -43,19 +117,25 @@ public class MazeBuilder
 		}
 	}
 	
-	private static void placeDoors(DirectedGraph<RoomData, DoorwayData> layout, World world, Point3D offset)
+	private static void decorateRooms(DirectedGraph<RoomData, DoorwayData> layout, World world, Point3D offset)
 	{
+		RoomData room;
+		PartitionNode<RoomData> partition;
+		ArrayList<LinkPlan> links = new ArrayList<LinkPlan>();
+		
+		// Iterate over all rooms and apply decorators
 		for (IGraphNode<RoomData, DoorwayData> node : layout.nodes())
 		{
-			RoomData room = node.data();
-			Point3D minCorner = room.getPartitionNode().minCorner();
-			if (!room.getOutboundLinks().isEmpty())
-			{
-				setBlockDirectly(world, offset.getX() + minCorner.getX(), offset.getY() + minCorner.getY() + 1,
-						offset.getZ() + minCorner.getZ(), Block.glowStone.blockID, 0);
-				setBlockDirectly(world, offset.getX() + minCorner.getX(), offset.getY() + minCorner.getY() + 2,
-						offset.getZ() + minCorner.getZ(), Block.glowStone.blockID, 0);
-			}
+			room = node.data();
+			partition = room.getPartitionNode();
+			links.addAll(room.getOutboundLinks());
+			
+			// TODO: Add decorator code here!
+		}
+		// Iterate over all links plans and place links in the world
+		for (LinkPlan link : links)
+		{
+			// TODO: Add link placement code here!
 		}
 	}
 	
@@ -70,12 +150,19 @@ public class MazeBuilder
 		{
 			for (IEdge<RoomData, DoorwayData> passage : node.outbound())
 			{
+				// Carve out the passage
 				doorway = passage.data();
 				axis = doorway.axis();
 				lower = doorway.minCorner();
 				carveDoorway(world, axis, offset.getX() + lower.getX(), offset.getY() + lower.getY(),
 						offset.getZ() + lower.getZ(), doorway.width(), doorway.height(), doorway.length(),
 						decay, random);
+				
+				// If this is a vertical passage, then mark the upper room as decayed
+				if (axis == DoorwayData.Y_AXIS)
+				{
+					passage.tail().data().setDecayed(true);
+				}
 			}
 		}
 	}
@@ -86,6 +173,8 @@ public class MazeBuilder
 		final int MIN_DOUBLE_DOOR_SPAN = 10;
 		
 		int gap;
+		int rx;
+		int rz;
 		switch (axis)
 		{
 			case DoorwayData.X_AXIS:
@@ -150,9 +239,10 @@ public class MazeBuilder
 					{
 						gap = 6;
 					}
-					decay.apply(world,
-							x + random.nextInt(width - gap - 1) + 1, y - 1,
-							z + random.nextInt(length - gap - 1) + 1, gap, 4, gap);
+					rx = x + random.nextInt(width - gap - 1) + 1;
+					rz = z + random.nextInt(length - gap - 1) + 1;
+					carveHole(world, rx + gap / 2, y, rz + gap / 2);
+					decay.apply(world, rx, y - 1, rz, gap, 4, gap);
 				}
 				else
 				{
@@ -184,6 +274,19 @@ public class MazeBuilder
 		setBlockDirectly(world, x, y + 1, z, 0, 0);
 	}
 	
+	private static void buildPocketWalls(MazeDesign design, World world, Point3D offset, DDProperties properties)
+	{
+		// Build the inner Fabric of Reality box
+		Point3D minCorner = new Point3D(-POCKET_WALL_GAP - 1, -POCKET_WALL_GAP - 1, -POCKET_WALL_GAP - 1);
+		Point3D maxCorner = new Point3D(design.width() + POCKET_WALL_GAP, design.height() + POCKET_WALL_GAP, design.length() + POCKET_WALL_GAP);
+		buildBox(world, offset, minCorner, maxCorner, properties.FabricBlockID, 0);
+		
+		// Build the outer Eternal Fabric box
+		minCorner.add(-1, -1, -1);
+		maxCorner.add(1, 1, 1);
+		buildBox(world, offset, minCorner, maxCorner, properties.PermaFabricBlockID, 0);
+	}
+	
 	private static void buildBox(World world, Point3D offset, Point3D minCorner, Point3D maxCorner, int blockID, int metadata)
 	{
 		int minX = minCorner.getX() + offset.getX();

src/main/java/StevenDimDoors/experimental/MazeDesign.java

@@ -4,16 +4,16 @@ import java.util.ArrayList;
 
 public class MazeDesign
 {
-	private PartitionNode root;
+	private PartitionNode<RoomData> root;
 	private DirectedGraph<RoomData, DoorwayData> layout;
 	
-	public MazeDesign(PartitionNode root, DirectedGraph<RoomData, DoorwayData> layout)
+	public MazeDesign(PartitionNode<RoomData> root, DirectedGraph<RoomData, DoorwayData> layout)
 	{
 		this.root = root;
 		this.layout = layout;
 	}
 
-	public PartitionNode getRootPartition()
+	public PartitionNode<RoomData> getRootPartition()
 	{
 		return root;
 	}

src/main/java/StevenDimDoors/experimental/MazeDesigner.java

@@ -589,93 +589,180 @@ public class MazeDesigner
 		// 3. Place internal links connecting the different sections of the maze
 		// 4. Place more internal links to confuse people
 		
-		// We need to start by counting the door capacity of each section and
-		// listing which rooms can have doors or destinations for each section.
+		// We need to start by building up data for each section, such as their
+		// door capacities and the rooms available for placing doors.
 		int index;
-		int[] capacity = new int[cores.size()];
-		ArrayList<RoomData>[] sourceRooms = (ArrayList<RoomData>[]) Array.newInstance(cores.getClass(), cores.size());
-		ArrayList<RoomData>[] destinationRooms = (ArrayList<RoomData>[]) Array.newInstance(cores.getClass(), cores.size());
+		int count;
+		SectionData selection;
+		SectionData destination;
+		ArrayList<SectionData> allSections;
+		ArrayList<SectionData> usableSections;
 
-		for (index = 0; index < sourceRooms.length; index++)
+		// Check if there is only one section. Our concerns differ depending
+		// on whether there is one or more than one.
+		if (cores.size() > 1)
 		{	
-			sourceRooms[index] = new ArrayList<RoomData>();
-			destinationRooms[index] = new ArrayList<RoomData>();
-			capacity[index] = listLinkRooms(cores.get(index).getLayoutNode(), sourceRooms[index], destinationRooms[index]);
+			// More than 1 section
+			allSections = new ArrayList<SectionData>(cores.size());
+			for (RoomData core : cores)
+			{
+				allSections.add( SectionData.createFromCore(core.getLayoutNode()) );
+			}
+			usableSections = (ArrayList<SectionData>) allSections.clone();
+			
+			// Select the room in which to place the entrance.
+			// We can safely consider all sections because createMazeSections()
+			// guarantees that each one has at least the capacity for 2 doors.
+			// Remove the selected section if it falls below a capacity of 2
+			// since we need to leave at least 1 capacity for section linking.
+			index = random.nextInt(usableSections.size());
+			selection = usableSections.get(index);
+			selection.createEntranceLink(random);
+			if (selection.capacity() <= 1)
+			{
+				usableSections.remove(index);
+			}
+			
+			// Place 3 to 4 dungeon doors in random sections
+			// Remove any sections that fall under a capacity of 2.
+			count = 3 + random.nextInt(2);
+			for (; count > 0 && !usableSections.isEmpty(); count--)
+			{
+				index = random.nextInt(usableSections.size());
+				selection = usableSections.get(index);
+				selection.createDungeonLink(random);
+				if (selection.capacity() <= 1)
+				{
+					usableSections.remove(index);
+				}
+			}
+			
+			// The next task is to place internal links. These links must connect
+			// the different maze sections to create a strongly connected graph.
+			linkMazeSections(allSections, random);
+			
+			// Add 1 to 3 extra internal links to confuse people
+			usableSections.clear();
+			for (SectionData section : allSections)
+			{
+				if (section.capacity() > 0)
+				{
+					usableSections.add(section);
+				}
+			}
+			count = 1 + random.nextInt(3);
+			for (; count > 0 && !usableSections.isEmpty(); count--)
+			{
+				index = random.nextInt(usableSections.size());
+				selection = usableSections.get(index);
+				destination = allSections.get( random.nextInt(allSections.size()) );
+				selection.reserveSectionLink(destination, random);
+				if (selection.capacity() == 0)
+				{
+					usableSections.remove(index);
+				}
+			}
+			
+			// Finally, make sure to process all reservations for section links.
+			for (SectionData section : allSections)
+			{
+				section.processReservedLinks(random);
+			}
+		}
+		else
+		{
+			// Only 1 section
+			selection = SectionData.createFromCore(cores.get(0).getLayoutNode());
+			// Place entrance door in a random room
+			selection.createEntranceLink(random);
+			// Place 3 to 4 dungeon doors or fewer, based on capacity
+			count = Math.min(3 + random.nextInt(2), selection.capacity());
+			for (; count > 0; count--)
+			{
+				selection.createDungeonLink(random);
+			}
 		}
-		
-		// Now we select the room in which to place the entrance.
-		// We can safely assume all source room lists are non-empty because
-		// createMazeSections() guarantees that each section has at least
-		// the capacity for 2 doors.
-		index = random.nextInt(sourceRooms.length);
-		createEntranceLink(sourceRooms[index], random.nextInt(sourceRooms[index].size()));
-		
-		// The next task is to place internal links. These links must connect
-		// the different maze sections to create a strongly connected graph.
-		
-		
 	}
 	
-	private static int listLinkRooms(IGraphNode<RoomData, DoorwayData> core,
-			ArrayList<RoomData> sourceRooms, ArrayList<RoomData> destinationRooms)
+	private static void linkMazeSections(ArrayList<SectionData> sections, Random random)
 	{
-		int capacity = 0;
-		boolean hasHoles;
-		RoomData currentRoom;
-		IGraphNode<RoomData, DoorwayData> current;
-		IGraphNode<RoomData, DoorwayData> neighbor;
-		Stack<IGraphNode<RoomData, DoorwayData>> ordering = new Stack<IGraphNode<RoomData, DoorwayData>>();
-		HashSet<IGraphNode<RoomData, DoorwayData>> visited = new HashSet<IGraphNode<RoomData, DoorwayData>>();
+		// This algorithm constructs links sections together using Dimensional Doors
+		// to create a random strongly connected graph. It takes into account capacity
+		// constraints as well. We assume that all sections have at least 1 door capacity.
+		final int EXTENSION_CHANCE = 2;
+		final int MAX_EXTENSION_CHANCE = 3;
 		
-		visited.add(core);
-		ordering.add(core);
-		while (!ordering.isEmpty())
+		int index;
+		SectionData start;
+		SectionData current;
+		SectionData next;
+		
+		// Total spare capacity of the sections not in "remaining"
+		int capacity;
+		// Sections not in the graph
+		ArrayList<SectionData> remaining = (ArrayList<SectionData>) sections.clone();
+		// Sections that are part of an incomplete cycle
+		ArrayList<SectionData> attached = new ArrayList<SectionData>(sections.size());
+		// Sections that are part of a cycle and thus strongly connected
+		ArrayList<SectionData> connected = new ArrayList<SectionData>(sections.size());
+		// Sections that are part of a cycle and have spare capacity - used to start new cycles
+		ArrayList<SectionData> starters = new ArrayList<SectionData>(sections.size());
+		
+		// Shuffle remaining to achieve randomness
+		Collections.shuffle(remaining, random);
+		// Remove the starting node to serve as the base of our strongly connected graph
+		start = remaining.remove(remaining.size() - 1);
+		starters.add(start);
+		connected.add(start);
+		capacity = start.capacity();
+		
+		// Repeat until all sections are connected
+		while (!remaining.isEmpty())
 		{
-			current = ordering.pop();
-			hasHoles = false;
-			
-			for (IEdge<RoomData, DoorwayData> edge : current.outbound())
+			// Select a section from which to start a new cycle
+			index = random.nextInt(starters.size());
+			start = starters.get(index);
+			// Select the first new section in the cycle and link to it
+			current = remaining.remove(remaining.size() - 1);
+			attached.add(current);
+			start.reserveSectionLink(current, random);
+			// Add the current section's capacity to the total, but subtract two to account
+			// for the link just created and for the future link from this section to another
+			capacity += current.capacity() - 2;
+			// Remove the starting section from starters if it has exhausted its capacity
+			if (start.capacity() == 0)
 			{
-				neighbor = edge.tail();
-				if (visited.add(neighbor))
-				{
-					ordering.add(neighbor);
-				}
-			}
-			for (IEdge<RoomData, DoorwayData> edge : current.inbound())
-			{
-				neighbor = edge.head();
-				if (visited.add(neighbor))
-				{
-					ordering.add(neighbor);
-				}
-				if (edge.data().axis() == DoorwayData.Y_AXIS)
-				{
-					hasHoles = true;
-				}
+				starters.remove(index);
 			}
 			
-			if (!hasHoles)
+			// Continue attaching sections to the partial cycle while there are are still sections
+			// left to be added and we have no spare capacity. Or we could randomly decide to
+			// continue even with spare capacity. Spare capacity means we could start a new cycle
+			// safely and still achieve strong connectivity. Randomness here influences the kinds
+			// of graphs we can get.
+			while (!remaining.isEmpty() && (capacity == 0 ||
+					random.nextInt(MAX_EXTENSION_CHANCE) < EXTENSION_CHANCE))
 			{
-				currentRoom = current.data();
-				destinationRooms.add(currentRoom);
-				if (currentRoom.estimateDoorCapacity() > 0)
+				next = remaining.remove(remaining.size() - 1);
+				attached.add(next);
+				current.reserveSectionLink(next, random);
+				// Account for this section's capacity, but subtract one for
+				// the future link that will connect this section to another
+				capacity += next.capacity() - 1;
+				current = next;
+			}
+			next = connected.get(random.nextInt(connected.size()));
+			current.reserveSectionLink(next, random);
+			for (SectionData section : attached)
+			{
+				connected.add(section);
+				if (section.capacity() > 0)
 				{
-					capacity += currentRoom.estimateDoorCapacity();
-					sourceRooms.add(currentRoom);
+					starters.add(section);
 				}
 			}
 		}
-		return capacity;
-	}
 		
-	private static void createEntranceLink(ArrayList<RoomData> sources, int index)
-	{
-		RoomData entranceRoom = sources.get(index);
-		LinkPlan.createEntranceLink(entranceRoom);
-		if (entranceRoom.getRemainingDoorCapacity() == 0)
-		{
-			sources.remove(index);
-		}
+		// Done! At this point, all sections are connected.
 	}
 }

src/main/java/StevenDimDoors/experimental/SectionData.java

@@ -0,0 +1,192 @@
+package StevenDimDoors.experimental;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Random;
+import java.util.Stack;
+
+public class SectionData
+{
+	// Specifies the chance of selecting a destination from protectedRooms
+	// rather than from destinationRooms (which will then become protected)
+	private static final int PROTECTED_DESTINATION_CHANCE = 4;
+	private static final int MAX_PROTECTED_DESTINATION_CHANCE = 5;
+	
+	private int capacity;
+	private ArrayList<RoomData> sourceRooms;
+	private ArrayList<RoomData> protectedRooms;
+	private ArrayList<RoomData> destinationRooms;
+	private ArrayList<LinkPlan> reservations; 
+	
+	private SectionData(ArrayList<RoomData> sourceRooms, ArrayList<RoomData> destinationRooms, int capacity)
+	{
+		this.capacity = capacity;
+		this.sourceRooms = sourceRooms;
+		this.destinationRooms = destinationRooms;
+		this.protectedRooms = new ArrayList<RoomData>();
+		this.reservations = new ArrayList<LinkPlan>();
+	}
+	
+	public static SectionData createFromCore(IGraphNode<RoomData, DoorwayData> core)
+	{
+		int capacity = 0;
+		ArrayList<RoomData> sourceRooms = new ArrayList<RoomData>();
+		ArrayList<RoomData> destinationRooms = new ArrayList<RoomData>();
+		
+		boolean hasHoles;
+		RoomData currentRoom;
+		IGraphNode<RoomData, DoorwayData> current;
+		IGraphNode<RoomData, DoorwayData> neighbor;
+		Stack<IGraphNode<RoomData, DoorwayData>> ordering = new Stack<IGraphNode<RoomData, DoorwayData>>();
+		HashSet<IGraphNode<RoomData, DoorwayData>> visited = new HashSet<IGraphNode<RoomData, DoorwayData>>();
+		
+		visited.add(core);
+		ordering.add(core);
+		while (!ordering.isEmpty())
+		{
+			current = ordering.pop();
+			hasHoles = false;
+			
+			for (IEdge<RoomData, DoorwayData> edge : current.outbound())
+			{
+				neighbor = edge.tail();
+				if (visited.add(neighbor))
+				{
+					ordering.add(neighbor);
+				}
+			}
+			for (IEdge<RoomData, DoorwayData> edge : current.inbound())
+			{
+				neighbor = edge.head();
+				if (visited.add(neighbor))
+				{
+					ordering.add(neighbor);
+				}
+				if (edge.data().axis() == DoorwayData.Y_AXIS)
+				{
+					hasHoles = true;
+				}
+			}
+			
+			if (!hasHoles)
+			{
+				currentRoom = current.data();
+				destinationRooms.add(currentRoom);
+				if (currentRoom.estimateDoorCapacity() > 0)
+				{
+					capacity += currentRoom.estimateDoorCapacity();
+					sourceRooms.add(currentRoom);
+				}
+			}
+		}
+		return new SectionData(sourceRooms, destinationRooms, capacity);
+	}
+	
+	public int capacity()
+	{
+		return capacity;
+	}
+	
+	public void createEntranceLink(Random random)
+	{
+		int index = random.nextInt(sourceRooms.size());
+		RoomData room = sourceRooms.get(index);
+		LinkPlan.createEntranceLink(room);
+		if (room.getRemainingDoorCapacity() == 0)
+		{
+			sourceRooms.remove(index);
+		}
+		// It's okay to check containment in this list because
+		// the number of protected rooms is expected to be small
+		if (!protectedRooms.contains(room))
+		{
+			protectedRooms.add(room);
+		}
+		capacity--;
+	}
+
+	public void createDungeonLink(Random random)
+	{
+		int index = random.nextInt(sourceRooms.size());
+		RoomData room = sourceRooms.get(index);
+		LinkPlan.createDungeonLink(room);
+		if (room.getRemainingDoorCapacity() == 0)
+		{
+			sourceRooms.remove(index);
+		}
+		// It's okay to check containment in this list because
+		// the number of protected rooms is expected to be small
+		if (!protectedRooms.contains(room))
+		{
+			protectedRooms.add(room);
+		}
+		capacity--;
+	}
+
+	public void reserveSectionLink(SectionData destination, Random random)
+	{
+		// This method "reserves" a link by decrementing the capacity of this
+		// section and assigning a source room to the link. However, assigning
+		// its destination in a particular section is deferred. Why?
+		
+		// We favor using source rooms as destinations to cut down the number
+		// of rooms that have to be marked as protected against decay effects.
+		// We defer assigning a destination until after all source rooms are
+		// known so that we have that information available. Otherwise,
+		// destination selection would be biased toward non-source rooms and
+		// rooms with dungeon doors, which are placed before section links.
+		
+		int index = random.nextInt(sourceRooms.size());
+		RoomData room = sourceRooms.get(index);
+		destination.reserveDestination(LinkPlan.createInternalLink(room));
+		if (room.getRemainingDoorCapacity() == 0)
+		{
+			sourceRooms.remove(index);
+		}
+		// It's okay to check containment in this list because
+		// the number of protected rooms is expected to be small
+		if (!protectedRooms.contains(room))
+		{
+			protectedRooms.add(room);
+		}
+		capacity--;
+	}
+
+	public void processReservedLinks(Random random)
+	{
+		for (LinkPlan link : reservations)
+		{
+			link.setDestination( getLinkDestination(random) );
+		}
+		reservations.clear();
+	}
+	
+	private void reserveDestination(LinkPlan link)
+	{
+		reservations.add(link);
+	}
+	
+	private RoomData getLinkDestination(Random random)
+	{
+		RoomData destination;
+		
+		// Choose whether to select a room that is already protected or select
+		// from all possible destination rooms. Note that some destination rooms
+		// may also be protected rooms already.
+		if (random.nextInt(MAX_PROTECTED_DESTINATION_CHANCE) < PROTECTED_DESTINATION_CHANCE)
+		{
+			destination = protectedRooms.get( random.nextInt(protectedRooms.size()) );
+		}
+		else
+		{
+			destination = destinationRooms.get( random.nextInt(destinationRooms.size()) );
+			// It's okay to check containment in this list because
+			// the number of protected rooms is expected to be small
+			if (!protectedRooms.contains(destination))
+			{
+				protectedRooms.add(destination);
+			}
+		}
+		return destination;
+	}
+}

src/main/java/StevenDimDoors/mod_pocketDim/Point3D.java

@@ -56,6 +56,13 @@ public class Point3D implements Serializable {
 		return this.z = z;
 	}
 
+	public void add(int x, int y, int z)
+	{
+		this.x += x;
+		this.y += y;
+		this.z += z;
+	}
+	
 	@Override
 	public Point3D clone()
 	{

src/main/java/StevenDimDoors/mod_pocketDim/world/PocketBuilder.java

@@ -477,7 +477,7 @@ public class PocketBuilder
 		}
 		*/
 		
-		MazeBuilder.generate(world, x, y, z, random);
+		MazeBuilder.generate(world, x, y, z, random, properties);
 
 		//Build the door
 		int doorOrientation = BlockRotator.transformMetadata(BlockRotator.EAST_DOOR_METADATA, orientation - BlockRotator.EAST_DOOR_METADATA + 2, properties.DimensionalDoorID);