Bind the surface rule tree to the world seed

The tree was parsed once, globally, and shared by every world -- so every
condition that needs the seed simply did not work. Compiling it per RandomState
fixes four of them at once.

noise_threshold sampled a per-column random draw and pretended it was
"minecraft:surface"; the other six noises it names were unsupported and returned
false. Each condition now holds its own seeded noise, sampled once per column
into a small cache the way vanilla's LazyXZCondition does. Powder snow, packed
ice and ice appear in the dump for the first time; calcite, swamp water windows
and gravel patches have their conditions back too.

vertical_gradient tapered through a per-column RNG shared with the other rules.
Vanilla rolls a positional random at the exact block, from a factory named by
the rule. More importantly the anchor decoder read only above_bottom and
discarded which kind of anchor it was, so the deepslate rule's absolute 0..8
collapsed onto y=-64 and **no deepslate existed anywhere in the world**. Anchors
now carry their kind and resolve against the real height bounds -- which also
retires a hardcoded 384 in y_above.

Two more stubs land with them: hole is surfaceDepth <= 0 rather than a constant
false, and steep reads the neighbouring column heights. steep needs the whole
chunk's heightmap, so the column pass is now two passes -- terrain and fluids
for all 256 columns, then surface rules -- which is the order vanilla uses
anyway (doFill, then buildSurface).

Deepslate was also missing from the block-ID table, and an unknown name resolved
to 0, which the caller read as "no block" and skipped. So even a correct rule
would have placed nothing. Unknown names are now a parse error, deepslate and
mud are in the table, and a rule that resolves to air genuinely places air --
the frozen-ocean surface asks for exactly that.

Below y=0 is now entirely deepslate, y=1..7 a scatter, above y=8 none.
This commit is contained in:
Master290 2026-07-27 02:25:09 +03:00
parent 1083e47211
commit c19e5f0e4f
9 changed files with 478 additions and 255 deletions

View file

@ -111,6 +111,20 @@ func main() {
countAt(16, 40, "y=16..40")
countAt(1, 7, "y=1..7 (transition)")
countAt(-64, -1, "y<0 (deepslate)")
// The deepslate rule is a vertical_gradient over absolute anchors 0..8:
// everything solid below y=0 is deepslate, everything above y=8 is stone,
// and the band between them is a scatter. A zero here means the rule is
// firing but its block is being dropped, or its anchors are misread.
switch {
case deepStone["y<0 (deepslate)"] == 0:
fmt.Println(" FAIL: no deepslate below y=0")
case deepStone["y=16..40"] != 0:
fmt.Println(" FAIL: deepslate above the transition band")
case deepStone["y=1..7 (transition)"] == 0:
fmt.Println(" FAIL: the stone/deepslate transition band is empty")
default:
fmt.Println(" OK: deepslate below y=0, scattered through y=1..7, none above")
}
// Bedrock floor: y=-64 must be solid bedrock everywhere, y=-63..-59 a
// thinning scatter of bedrock over stone/deepslate, and NOTHING in that band