Biome Cleaner

This release is mostly a performance pass aimed at modpacks running parallel chunk generation (C2ME and similar), plus one fix for custom configs. Cleanup output is unchanged from 1.1.4 apart from the specific case described in the fix below — same seed still gives the same biomes.

Changed

• Smoother chunk generation, especially with C2ME and similar parallel-worldgen mods. A round of performance tuning to the cleanup hot path. The biggest win is on modpacks where lots of chunks are being generated at once: less time spent waiting on shared work, less garbage churn for the GC to clean up, and fewer hitches when you fly into unexplored terrain. Single-player vanilla setups will see a smaller but still positive change. No effect on the biomes the cleaner produces — same world, same output, just less overhead.

• The cache size now scales with your allocated RAM by default. Previous releases used a fixed 128 MB cache budget no matter how much memory you'd given Minecraft. The default now scales with the heap — on an 8 GB allocation that's about 164 MB, roughly 28% more entries cached, which means fewer redundant lookups during chunk generation. If you're upgrading from an older version, your existing config still has the old fixed value written in it and Minecraft won't touch your config file on its own. To switch to auto-sizing, open config/biome-cleanup/advanced.json, find the cacheMemoryMB line, and either delete it or change the number to 0. If you'd rather keep an explicit budget, leave it as a positive number — the mod will respect it. The startup log now prints whether your cache is on auto or explicit so you can confirm which mode you're running.

Fixed

• Custom size ranges could paint biomes into places they shouldn't exist. This affected users of the [min, max] size-range syntax (introduced in 1.1.0) when their config had overlapping group and per-biome entries. When the cleaner trimmed an oversized region, it had to pick a "filler" biome for the trimmed-off portion — and the old logic could pick a filler that didn't actually exist anywhere in the surrounding terrain. The reported case: on a Minecraft 26.1 world with a custom config combining a "beaches" group default and a [32, 64] range on minecraft:beach, an oversized warm-coast beach got partially repainted as snowy_beach, even though no snowy beach existed anywhere nearby. A neighbouring savanna island then got pulled toward snowy_beach too, treating the painted-in patch as its new neighbour. The cleaner now only picks a filler biome that actually borders the region in the surrounding terrain; if no real neighbour qualifies, the region is left at its original size rather than painted with something that doesn't belong there. Default-config worlds are nearly unchanged. A small number of oversized stony_shore patches that 1.1.4 used to trim by inventing an adjacent beach will now stay at their original size; this only matters if you've actually set a range on stony_shore in your config, and we'd rather leave a real shore intact than paint a phantom beach next to it.