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ChunkMeshWorker.update() sorted the whole proximity list front-to-back and then filtered while walking it, so it ordered thousands of chunks to decide the order of the handful dirty that frame. Filtering first and sorting only those gives the same sequence - ordering and filtering commute here. update() runs once per frame, from RenderableWorldImpl's first rendering stage. Measured on a reproduction of the list and comparator, at the MEGA view distance of 33x7x33 = 7623 chunks: sort-all, list nearly sorted from last frame: ~200us/frame filter-then-sort: ~27us/frame roughly 7x, or ~0.2ms of a 16.7ms frame. The nearly-sorted row is the honest one - a frame re-sorts what it sorted last frame, perturbed only by camera drift, which TimSort handles in about O(n); on a shuffled list the same measurement is ~1.2ms. Either way the cost did not move when the dirty count went from 5 to 50, which is the tell that it was all in touching the list rather than in the queueing. The comparator is not cheap per call: it re-reads the camera through a Provider and, via Chunk.getRenderPosition(), allocates two Vector3f per comparison. So this is really about calling it O(dirty log dirty) times instead of O(n log n). isDirty() is still re-checked immediately before each emit rather than only when the list is built. Emitting can drive mesh generation synchronously, which clears the flag, and add() does not deduplicate - so a chunk present in the proximity list more than once would otherwise be queued again for a mesh the emission before it just produced. ChunkMeshWorkerTest's testChunkIsNotProcessedTwice covers exactly that and caught it. Measured with a throwaway reproduction rather than the real classes: 7623 real ChunkImpls is about a gigabyte, since each carries a dense 16-bit block array. The comparator stand-in used one indirection for the camera where the real one uses two, so the figures understate rather than flatter. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
…s per-frame dirty-chunk list
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From skrcode's PR #5391 review comment (9863 -> 3128 bytes/update measured). Single-threaded, one call per frame - safe to reuse. Cleared in finally. Co-Authored-By: soloturn <soloturn@gmail.com>
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This is a one-commit JAIPilot Cloud follow-up on the exact current head of MovingBlocks/Terasology#5367. It targets that PR branch directly.
Change
Reuse a private per-worker ArrayList for the ready-and-dirty chunk set instead of allocating a new list every rendered frame. A finally block clears the scratch list on both normal and exceptional exits.
Proof
Boundary and disclosure
The session did not complete the entire engine-tests suite, so this claims only the focused tests and affected-module gates. The unchanged comparator remains the dominant allocator. The measurement uses synthetic DummyChunks and is an allocation-count proof, not an end-to-end frame-rate claim.
JAIPilot Cloud generated and validated the patch in skrcode/Terasology#2. I reviewed the exact ancestry, complete one-file diff, call-path ownership evidence, and verification boundary before offering it here.