Three Dash Structure Optimizer

2.0.1

• Template hot set: the structure files your pack asks for most are prepared in background threads while the server starts, before the first chunks need them.
• Warm-up in the idle seconds after start: the small square of chunks around the spawn that the first player needs anyway is generated while nobody is online (4 s time budget, stops when a player joins); the start-up is not delayed.
• Faster biome fill (26.2): climate values that do not depend on height are computed once per column, with a self-check against the game's own values.
• Faster chunk saving (26.2): section palettes are written to NBT directly instead of through DataFixerUpper codec chains (6 % fewer allocated bytes on the generation threads), compared with the game's codec on the first 20,000 containers.
• Cheaper structure-terrain filter: no per-sample allocation in the hook, and structures with "bury" terrain adaptation reach 6 blocks instead of 12 (exactly the same terrain).
• Fixes from a review: natural-spawn chunk pacing is now OFF by default (it halved spawn attempts far from players); the climate cache keeps checking itself for the whole run; the spawn warm-up works again in a second world of the same session; one damaged line no longer wipes the template hot set; a BOM in the config file no longer eats the first option.
• Faster generation on an empty server (universal.jit_tuning, on): while nobody is online the mod makes the Java C2 compiler start 4x later (-4.5 % generation time, -6 % CPU); the game's own values come back when the first player joins, so a running server is unchanged.
• Benchmark (58 structure mods, 3,481 chunks): generation 24.1 s -> 19.3 s (-20 %) against 2.0.0; at 72x structure density 11.7 s -> 10.0 s; the area around a joining player loads 3-4 s sooner.
• Fabric, NeoForge, Forge; Minecraft 26.2 and 26.3 (the climate cache and the chunk-save change are 26.2).
• Final build: start-up crashes fixed that only showed on some loader/game combinations (a hook aimed at a class that is an interface on 26.3; hooks on methods that NeoForge and Forge change; two helper classes inside hook classes). Checked: the mod starts and runs 5-minute flights on Fabric, NeoForge and Forge for 26.2 and 26.3 with no hook errors.
• An experimental structure-biome pre-filter is OFF (it could drop structures vanilla builds and gave no measurable speed): -Dstructure_omg_optimization.structure_biome_prefilter=off|chunk|probe