src/main/java/net/glowstone/GlowChunk.java

package net.glowstone;

import org.bukkit.Chunk;
import org.bukkit.ChunkSnapshot;
import org.bukkit.block.BlockState;
import org.bukkit.entity.Entity;

import net.glowstone.block.GlowBlock;
import net.glowstone.msg.CompressedChunkMessage;
import net.glowstone.msg.Message;

/**
 * Represents a chunk of the map.
 * @author Graham Edgecombe
 */
public final class GlowChunk implements Chunk {

	/**
	 * The radius (not including the current chunk) of the chunks that the
	 * player can see.
	 */
	public static final int VISIBLE_RADIUS = 8;

	/**
	 * A chunk key represents the X and Z coordinates of a chunk and implements
	 * the {@link #hashCode()} and {@link #equals(Object)} methods making it
	 * suitable for use as a key in a hash table or set.
	 * @author Graham Edgecombe
	 */
	public static final class Key {

		/**
		 * The coordinates.
		 */
		private final int x, z;

		/**
		 * Creates a new chunk key with the specified X and Z coordinates.
		 * @param x The X coordinate.
		 * @param z The Z coordinate.
		 */
		public Key(int x, int z) {
			this.x = x;
			this.z = z;
		}

		/**
		 * Gets the X coordinate.
		 * @return The X coordinate.
		 */
		public int getX() {
			return x;
		}

		/**
		 * Gets the Z coordinate.
		 * @return The Z coordinate.
		 */
		public int getZ() {
			return z;
		}

		@Override
		public int hashCode() {
			final int prime = 31;
			int result = 1;
			result = prime * result + x;
			result = prime * result + z;
			return result;
		}

		@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			Key other = (Key) obj;
			if (x != other.x)
				return false;
			if (z != other.z)
				return false;
			return true;
		}

	}

	/**
	 * The dimensions of a chunk.
	 */
	public static final int WIDTH = 16, HEIGHT = 16, DEPTH = 128;
    
    /**
     * The world of this chunk.
     */
    private final GlowWorld world;

	/**
	 * The coordinates of this chunk.
	 */
	private final int x, z;

	/**
	 * The data in this chunk representing all of the blocks and their state.
	 */
	private final byte[] types, metaData, skyLight, blockLight;
    
    /**
     * Whether the chunk has been populated by special features.
     * Used in map generation.
     */
    private boolean populated = false;

	/**
	 * Creates a new chunk with a specified X and Z coordinate.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 */
	public GlowChunk(GlowWorld world, int x, int z) {
        this.world = world;
		this.x = x;
		this.z = z;
		this.types = new byte[WIDTH * HEIGHT * DEPTH];
		this.metaData = new byte[WIDTH * HEIGHT * DEPTH];
		this.skyLight = new byte[WIDTH * HEIGHT * DEPTH];
		this.blockLight = new byte[WIDTH * HEIGHT * DEPTH];
        
        for (int i = 0; i < WIDTH * HEIGHT * DEPTH; ++i) {
            skyLight[i] = 15;
        }
	}

	/**
	 * Gets the X coordinate of this chunk.
	 * @return The X coordinate of this chunk.
	 */
	public int getX() {
		return x;
	}

	/**
	 * Gets the Z coordinate of this chunk.
	 * @return The Z coordinate of this chunk.
	 */
	public int getZ() {
		return z;
	}
    
    /**
     * Gets whether this chunk has been populated by special features.
     * @return Population status.
     */
    public boolean getPopulated() {
        return populated;
    }
    
    /**
     * Sets the population status of this chunk.
     * @param populated Population status.
     */
    public void setPopulated(boolean populated) {
        this.populated = populated;
    }

	/**
	 * Gets the type of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @return The type.
	 */
	public int getType(int x, int z, int y) {
		return types[coordToIndex(x, z, y)];
	}

	/**
	 * Sets the types of all tiles within the chunk.
	 * @param types The array of types.
	 */
	public void setTypes(byte[] types){
		if (types.length != WIDTH * HEIGHT * DEPTH) {
			throw new IllegalArgumentException();
		}
		System.arraycopy(types, 0, this.types, 0, types.length);
	}

	/**
	 * Sets the type of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @param type The type.
	 */
	public void setType(int x, int z, int y, int type) {
		if (type < 0 || type >= 256)
			throw new IllegalArgumentException();

		types[coordToIndex(x, z, y)] = (byte) type;
	}

	/**
	 * Gets the metadata of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @return The metadata.
	 */
	public int getMetaData(int x, int z, int y) {
		return metaData[coordToIndex(x, z, y)];
	}

	/**
	 * Sets the metadata of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @param metaData The metadata.
	 */
	public void setMetaData(int x, int z, int y, int metaData) {
		if (metaData < 0 || metaData >= 16)
			throw new IllegalArgumentException();

		this.metaData[coordToIndex(x, z, y)] = (byte) metaData;
	}

	/**
	 * Gets the sky light level of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @return The sky light level.
	 */
	public int getSkyLight(int x, int z, int y) {
		return skyLight[coordToIndex(x, z, y)];
	}

	/**
	 * Sets the sky light level of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @param skyLight The sky light level.
	 */
	public void setSkyLight(int x, int z, int y, int skyLight) {
		if (skyLight < 0 || skyLight >= 16)
			throw new IllegalArgumentException();

		this.skyLight[coordToIndex(x, z, y)] = (byte) skyLight;
	}

	/**
	 * Gets the block light level of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @return The block light level.
	 */
	public int getBlockLight(int x, int z, int y) {
		return blockLight[coordToIndex(x, z, y)];
	}

	/**
	 * Sets the block light level of a block within this chunk.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @param blockLight The block light level.
	 */
	public void setBlockLight(int x, int z, int y, int blockLight) {
		if (blockLight < 0 || blockLight >= 16)
			throw new IllegalArgumentException();

		this.blockLight[coordToIndex(x, z, y)] = (byte) blockLight;
	}

	/**
	 * Creates a new {@link Message} which can be sent to a client to stream
	 * this chunk to them.
	 * @return The {@link CompressedChunkMessage}.
	 */
	public Message toMessage() {
		return new CompressedChunkMessage(x * GlowChunk.WIDTH, z * GlowChunk.HEIGHT, 0, WIDTH, HEIGHT, DEPTH, serializeTileData());
	}

	/**
	 * Converts a three-dimensional coordinate to an index within the
	 * one-dimensional arrays.
	 * @param x The X coordinate.
	 * @param z The Z coordinate.
	 * @param y The Y coordinate.
	 * @return The index within the arrays.
	 */
	private int coordToIndex(int x, int z, int y) {
		if (x < 0 || z < 0 || y < 0 || x >= WIDTH || z >= HEIGHT || y >= DEPTH)
			throw new IndexOutOfBoundsException();

		return (x * HEIGHT + z) * DEPTH + y;
	}

	/**
	 * Serializes tile data into a byte array.
	 * @return The byte array populated with the tile data.
	 */
	private byte[] serializeTileData() {
		byte[] dest = new byte[((WIDTH * HEIGHT * DEPTH * 5) / 2)];

		System.arraycopy(types, 0, dest, 0, types.length);

		int pos = types.length;

		for (int i = 0; i < metaData.length; i += 2) {
			byte meta1 = metaData[i];
			byte meta2 = metaData[i + 1];
			dest[pos++] = (byte) ((meta2 << 4) | meta1);
		}

		for (int i = 0; i < skyLight.length; i += 2) {
			byte light1 = skyLight[i];
			byte light2 = skyLight[i + 1];
			dest[pos++] = (byte) ((light2 << 4) | light1);
		}

		for (int i = 0; i < blockLight.length; i += 2) {
			byte light1 = blockLight[i];
			byte light2 = blockLight[i + 1];
			dest[pos++] = (byte) ((light2 << 4) | light1);
		}

		return dest;
	}

    public GlowWorld getWorld() {
        return world;
    }

    public GlowBlock getBlock(int x, int y, int z) {
        return getWorld().getBlockAt(this.x << 4 | x, y, this.z << 4 | z);
    }

    public Entity[] getEntities() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    public BlockState[] getTileEntities() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    public ChunkSnapshot getChunkSnapshot() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

}