Method updateMapData

src/main/java/net/minecraft/item/ItemMap.java:65–229

(World worldIn, Entity viewer, MapData data)

    }

    public void updateMapData(World worldIn, Entity viewer, MapData data)
    {
        if (worldIn.provider.getDimensionId() == data.dimension && viewer instanceof EntityPlayer)
        {
            int i = 1 << data.scale;
            int j = data.xCenter;
            int k = data.zCenter;
            int l = MathHelper.floor_double(viewer.posX - (double)j) / i + 64;
            int i1 = MathHelper.floor_double(viewer.posZ - (double)k) / i + 64;
            int j1 = 128 / i;

            if (worldIn.provider.getHasNoSky())
            {
                j1 /= 2;
            }

            MapData.MapInfo mapdata$mapinfo = data.getMapInfo((EntityPlayer)viewer);
            ++mapdata$mapinfo.field_82569_d;
            boolean flag = false;

            for (int k1 = l - j1 + 1; k1 < l + j1; ++k1)
            {
                if ((k1 & 15) == (mapdata$mapinfo.field_82569_d & 15) || flag)
                {
                    flag = false;
                    double d0 = 0.0D;

                    for (int l1 = i1 - j1 - 1; l1 < i1 + j1; ++l1)
                    {
                        if (k1 >= 0 && l1 >= -1 && k1 < 128 && l1 < 128)
                        {
                            int i2 = k1 - l;
                            int j2 = l1 - i1;
                            boolean flag1 = i2 * i2 + j2 * j2 > (j1 - 2) * (j1 - 2);
                            int k2 = (j / i + k1 - 64) * i;
                            int l2 = (k / i + l1 - 64) * i;
                            Multiset<MapColor> multiset = HashMultiset.<MapColor>create();
                            Chunk chunk = worldIn.getChunkFromBlockCoords(new BlockPos(k2, 0, l2));

                            if (!chunk.isEmpty())
                            {
                                int i3 = k2 & 15;
                                int j3 = l2 & 15;
                                int k3 = 0;
                                double d1 = 0.0D;

                                if (worldIn.provider.getHasNoSky())
                                {
                                    int l3 = k2 + l2 * 231871;
                                    l3 = l3 * l3 * 31287121 + l3 * 11;

                                    if ((l3 >> 20 & 1) == 0)
                                    {
                                        multiset.add(Blocks.dirt.getMapColor(Blocks.dirt.getDefaultState().withProperty(BlockDirt.VARIANT, BlockDirt.DirtType.DIRT)), 10);
                                    }
                                    else
                                    {
                                        multiset.add(Blocks.stone.getMapColor(Blocks.stone.getDefaultState().withProperty(BlockStone.VARIANT, BlockStone.EnumType.STONE)), 100);