private void ParseSection(SubChunk section, ReadOnlyMemory <byte> data)
{
var reader = new MemoryStreamReader(data);
var version = reader.ReadByte();
if (version != 8)
{
throw new Exception("Wrong chunk version");
}
var storageSize = reader.ReadByte();
for (int storage = 0; storage < storageSize; storage++)
{
byte paletteAndFlag = (byte)reader.ReadByte();
bool isRuntime = (paletteAndFlag & 1) != 0;
if (isRuntime)
{
throw new Exception("Can't use runtime for persistent storage.");
}
int bitsPerBlock = paletteAndFlag >> 1;
int blocksPerWord = (int)Math.Floor(32d / bitsPerBlock);
int wordCount = (int)Math.Ceiling(4096d / blocksPerWord);
long blockIndex = reader.Position;
reader.Position += wordCount * 4;
int paletteSize = reader.ReadInt32();
var palette = new Dictionary <int, int>();
for (int j = 0; j < paletteSize; j++)
{
var file = new NbtFile
{
BigEndian = false,
UseVarInt = false
};
file.LoadFromStream(reader, NbtCompression.None);
var tag = (NbtCompound)file.RootTag;
Block block = BlockFactory.GetBlockByName(tag["name"].StringValue);
if (block != null && block.GetType() != typeof(Block) && !(block is Air))
{
List <IBlockState> blockState = ReadBlockState(tag);
block.SetState(blockState);
}
else
{
block = new Air();
}
palette.Add(j, block.GetRuntimeId());
}
long nextStore = reader.Position;
reader.Position = blockIndex;
int position = 0;
for (int wordIdx = 0; wordIdx < wordCount; wordIdx++)
{
uint word = reader.ReadUInt32();
for (int block = 0; block < blocksPerWord; block++)
{
if (position >= 4096)
{
continue; // padding bytes
}
int state = (int)((word >> ((position % blocksPerWord) * bitsPerBlock)) & ((1 << bitsPerBlock) - 1));
int x = (position >> 8) & 0xF;
int y = position & 0xF;
int z = (position >> 4) & 0xF;
if (state > palette.Count)
{
Log.Error($"Got wrong state={state} from word. bitsPerBlock={bitsPerBlock}, blocksPerWord={blocksPerWord}, Word={word}");
}
if (storage == 0)
{
section.SetBlockByRuntimeId(x, y, z, palette[state]);
}
else
{
section.SetLoggedBlockByRuntimeId(x, y, z, palette[state]);
}
position++;
}
}
reader.Position = nextStore;
}
}