blocks.json lists a block's states in getPossibleStates() order -- the property
cartesian product -- and separately marks which one is the default. The parser
declared only id and properties, so the default flag was dropped on the floor
and nameToStateID returned states[0]. Those differ for 642 of the 1168 blocks.
What that produced, measured rather than guessed: every redstone vein in the
world was lit=true and glowing, every sunflower was placed as its own top half
with nothing under it, and oak stairs came out upside down and waterlogged. It
also quietly disagreed with the StateGrass, StateOakLog and StateOakLeaf
constants next door in encode.go, which are the real defaults.
Now it starts from the default state and applies the properties it recognises,
keeping the default's value for an unknown key or an illegal value -- which is
what vanilla does when it reads a palette entry. That matters on the disk path:
a chunk written with a property we no longer know used to decode to a random
corner state instead of something sane.
The signature grows an ok result, because air was doing double duty as both a
real block and "no such name".
Separately, blockPaletteEntry filled the Properties compound by ranging a Go
map. nbt.Compound preserves insertion order precisely so encoding is
deterministic, so saving one chunk twice produced different region-file bytes
for every multi-property block. Keys are sorted now.
The world now survives restarts: chunks load from disk (read-through
cache) and player edits persist via async autosave + a final SaveAll on
shutdown. RegionIO finally does region I/O.
- world/regionfile.go: Anvil .mca container — 8192-byte header
(offset + timestamp tables), 4096-byte sectors, zlib chunk records.
- world/compress.go: zlib deflate/inflate for chunk payloads.
- world/store.go: chunk <-> Level-nested NBT (per-section
block_states/biomes palettes, WORLD_SURFACE heightmap, DataVersion
4790, yPos -4) via the existing nbt package; Store opens one
RegionFile per region with proper floor-division coords.
- world/state_names.go: id->name bridge from the embedded blocks.json
report so network int-IDs round-trip through the disk named palette.
- world/encode.go: GetBiome read accessor for serialization.
- world/cache.go: read-through (disk then generation), dirty tracking,
StartAutosave (returns a done channel so the saver exits before
Close), SaveAll, NewCacheWithStore.
- server.go + main.go: Config.WorldDir (default "world"), -world flag,
autosave loop every 30s, SaveAll + store Close on signal.
- Tests: region round-trip/absent/overwrite, chunk NBT round-trip,
end-to-end save-reload, negative chunk coords, autosave persistence.
