MapChunk.java

package com.hypixel.hytale.protocol.packets.worldmap;

import com.hypixel.hytale.protocol.io.ValidationResult;
import io.netty.buffer.ByteBuf;
import java.util.Objects;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;

public class MapChunk {
   public static final int NULLABLE_BIT_FIELD_SIZE = 1;
   public static final int FIXED_BLOCK_SIZE = 9;
   public static final int VARIABLE_FIELD_COUNT = 1;
   public static final int VARIABLE_BLOCK_START = 9;
   public static final int MAX_SIZE = 16384023;
   public int chunkX;
   public int chunkZ;
   @Nullable
   public MapImage image;

   public MapChunk() {
   }

   public MapChunk(int chunkX, int chunkZ, @Nullable MapImage image) {
      this.chunkX = chunkX;
      this.chunkZ = chunkZ;
      this.image = image;
   }

   public MapChunk(@Nonnull MapChunk other) {
      this.chunkX = other.chunkX;
      this.chunkZ = other.chunkZ;
      this.image = other.image;
   }

   @Nonnull
   public static MapChunk deserialize(@Nonnull ByteBuf buf, int offset) {
      MapChunk obj = new MapChunk();
      byte nullBits = buf.getByte(offset);
      obj.chunkX = buf.getIntLE(offset + 1);
      obj.chunkZ = buf.getIntLE(offset + 5);
      int pos = offset + 9;
      if ((nullBits & 1) != 0) {
         obj.image = MapImage.deserialize(buf, pos);
         pos += MapImage.computeBytesConsumed(buf, pos);
      }

      return obj;
   }

   public static int computeBytesConsumed(@Nonnull ByteBuf buf, int offset) {
      byte nullBits = buf.getByte(offset);
      int pos = offset + 9;
      if ((nullBits & 1) != 0) {
         pos += MapImage.computeBytesConsumed(buf, pos);
      }

      return pos - offset;
   }

   public void serialize(@Nonnull ByteBuf buf) {
      byte nullBits = 0;
      if (this.image != null) {
         nullBits = (byte)(nullBits | 1);
      }

      buf.writeByte(nullBits);
      buf.writeIntLE(this.chunkX);
      buf.writeIntLE(this.chunkZ);
      if (this.image != null) {
         this.image.serialize(buf);
      }

   }

   public int computeSize() {
      int size = 9;
      if (this.image != null) {
         size += this.image.computeSize();
      }

      return size;
   }

   public static ValidationResult validateStructure(@Nonnull ByteBuf buffer, int offset) {
      if (buffer.readableBytes() - offset < 9) {
         return ValidationResult.error("Buffer too small: expected at least 9 bytes");
      } else {
         byte nullBits = buffer.getByte(offset);
         int pos = offset + 9;
         if ((nullBits & 1) != 0) {
            ValidationResult imageResult = MapImage.validateStructure(buffer, pos);
            if (!imageResult.isValid()) {
               return ValidationResult.error("Invalid Image: " + imageResult.error());
            }

            pos += MapImage.computeBytesConsumed(buffer, pos);
         }

         return ValidationResult.OK;
      }
   }

   public MapChunk clone() {
      MapChunk copy = new MapChunk();
      copy.chunkX = this.chunkX;
      copy.chunkZ = this.chunkZ;
      copy.image = this.image != null ? this.image.clone() : null;
      return copy;
   }

   public boolean equals(Object obj) {
      if (this == obj) {
         return true;
      } else if (!(obj instanceof MapChunk)) {
         return false;
      } else {
         MapChunk other = (MapChunk)obj;
         return this.chunkX == other.chunkX && this.chunkZ == other.chunkZ && Objects.equals(this.image, other.image);
      }
   }

   public int hashCode() {
      return Objects.hash(new Object[]{this.chunkX, this.chunkZ, this.image});
   }
}