How to use

net.minecraft.world.storage.MapData

constructor

public static ItemStack setupNewMap(World worldIn, double worldX, double worldZ, byte scale, boolean trackingPosition, boolean unlimitedTracking)
{
  ItemStack itemstack = new ItemStack(ModItems.EREBUS_MAP_FILLED, 1, worldIn.getUniqueDataId("map"));
  String s = "map_" + itemstack.getMetadata();
  MapData mapdata = new MapData(s);
  worldIn.setData(s, mapdata);
  mapdata.scale = scale;
  mapdata.calculateMapCenter(worldX, worldZ, mapdata.scale);
  mapdata.dimension = worldIn.provider.getDimension();
  mapdata.trackingPosition = trackingPosition;
  mapdata.unlimitedTracking = unlimitedTracking;
  mapdata.markDirty();
  return itemstack;
}

protected static void enableMapTracking(ItemStack p_185064_0_, World p_185064_1_)
{
  MapData mapdata = ((ItemErebusMap) ModItems.EREBUS_MAP_FILLED).getMapData(p_185064_0_, p_185064_1_);
  p_185064_0_.setItemDamage(p_185064_1_.getUniqueDataId("map"));
  MapData mapdata1 = new MapData("map_" + p_185064_0_.getMetadata());
  mapdata1.trackingPosition = true;
  if (mapdata != null)
  {
    mapdata1.xCenter = mapdata.xCenter;
    mapdata1.zCenter = mapdata.zCenter;
    mapdata1.scale = mapdata.scale;
    mapdata1.dimension = mapdata.dimension;
    mapdata1.markDirty();
    p_185064_1_.setData("map_" + p_185064_0_.getMetadata(), mapdata1);
  }
}

MapData mapdata = new MapData(s);
world.setData(s, mapdata);
mapdata.scale = 1;

protected static void scaleMap(ItemStack p_185063_0_, World p_185063_1_, int p_185063_2_)
{
  MapData mapdata = ((ItemErebusMap) ModItems.EREBUS_MAP_FILLED).getMapData(p_185063_0_, p_185063_1_);
  p_185063_0_.setItemDamage(p_185063_1_.getUniqueDataId("map"));
  MapData mapdata1 = new MapData("map_" + p_185063_0_.getMetadata());
  if (mapdata != null)
  {
    mapdata1.scale = (byte)MathHelper.clamp(mapdata.scale + p_185063_2_, 0, 4);
    mapdata1.trackingPosition = mapdata.trackingPosition;
    mapdata1.calculateMapCenter((double)mapdata.xCenter, (double)mapdata.zCenter, mapdata1.scale);
    mapdata1.dimension = mapdata.dimension;
    mapdata1.markDirty();
    p_185063_1_.setData("map_" + p_185063_0_.getMetadata(), mapdata1);
  }
}

public static ItemStack createMap(World world, BlockPos pos, TradeInfo info) {
  BlockPos biomePos = BiomeLocator.spiralOutwardsLookingForBiome(world, info.biome, pos.getX(), pos.getZ());
  if(biomePos == null)
    return ItemStack.EMPTY;
  
  int id = world.getUniqueDataId("map");
  ItemStack stack = new ItemStack(Items.FILLED_MAP, 1, id);
  stack.setTranslatableName(info.name);
  NBTTagCompound cmp = ItemNBTHelper.getCompound(stack, "display", false);
  cmp.setInteger("MapColor", info.color);
  ItemNBTHelper.setCompound(stack, "display", cmp);
  String s = "map_" + id;
  MapData mapdata = new MapData(s);
  world.setData(s, mapdata);
  mapdata.scale = 2;
  mapdata.xCenter = biomePos.getX() + (int) ((Math.random() - 0.5) * 200);
  mapdata.zCenter = biomePos.getZ() + (int) ((Math.random() - 0.5) * 200);
  mapdata.dimension = 0;
  mapdata.trackingPosition = true;
  mapdata.unlimitedTracking = true;
  ItemMap.renderBiomePreviewMap(world, stack);
  MapData.addTargetDecoration(stack, biomePos, "+", Type.TARGET_X);
  return stack;
}

@Nullable
public MapData getMapData(ItemStack stack, World worldIn)
{
  String s = "map_" + stack.getMetadata();
  MapData mapdata = (MapData)worldIn.loadData(MapData.class, s);
  if (mapdata == null && !worldIn.isRemote)
  {
    stack.setItemDamage(worldIn.getUniqueDataId("map"));
    s = "map_" + stack.getMetadata();
    mapdata = new MapData(s);
    mapdata.scale = 3;
    mapdata.calculateMapCenter((double)worldIn.getWorldInfo().getSpawnX(), (double)worldIn.getWorldInfo().getSpawnZ(), mapdata.scale);
    mapdata.dimension = worldIn.provider.getDimension();
    mapdata.markDirty();
    worldIn.setData(s, mapdata);
  }
  return mapdata;
}