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.
Replaces the biome-blind fillVanillaColumn heuristics with a full
interpreter for the overworld surface_rule tree (already embedded in
overworld.json): block/sequence/condition/bandlands rules plus all 11
condition tests (biome, steep, hole, water, temperature, y_above,
stone_depth, noise_threshold, not, vertical_gradient,
above_preliminary_surface).
- worldgen/blockids.go: name(+Properties)→network-ID table for surface
blocks (grass/sand/terracotta/mycelium/podzol/coarse_dirt/sandstone/
calcite/snow/ice/...), with snowy property variants.
- worldgen/surface.go: rule-tree parser + interpreter + SurfaceContext;
LoadOverworldSurfaceRule caches the seed-independent tree.
- loader.go: OverworldDensity.SurfaceRule() exposes the parsed tree.
- biome_lookup.go: BiomeNameAt returns the biome name for biome tests.
- vanilla.go: samples the 2D climate + biome before column fill, threads
the rule tree and biome name into fillVanillaColumn, and applies it
top-down with stone as the default for non-matching (deeper) blocks.
The above_preliminary_surface gate uses an inclusive bound so the top
solid block reaches the biome dispatch.
- Performance: one per-column RNG and a reused SurfaceContext keep the
overhead to ~+13ms/chunk (71ms vs 58ms baseline), within the gate.
