Per docs/plans/2026-05-10-perf-tiers-2-3-roadmap.md Tier 1: cache the
per-(entity, meshRef, batch) classification (TextureCache lookup,
GroupKey hash, _groups dict insert) so the per-frame Draw inner loop
becomes "look up cache → walk assignments → append matrix to group's
Matrices list."
For static entities (~95% of world: trees, rocks, buildings, scenery),
the answer never changes between frames. Cache once at first visit;
reuse permanently. Per-frame work for static drops from 4 expensive
operations per (meshRef, batch) to 1 list-append.
Estimated entity dispatcher: 3.5ms → ~1-1.5ms median at radius=12.
Should land inside the 2.0ms spec budget.
Implementation:
- New EntityClassificationCache class (per-meshRef list of cached
(group ref, baked-PartTransform) tuples) keyed by entity.Id.
- ClassifyEntity does the one-time work; result populates _groups and
the cache.
- Draw inner loop: cache lookup → for each assignment, model =
PartTransform × entityWorld; group.Matrices.Add(model).
- Cache miss when ClassifyEntity finds NO mesh loaded yet (Vao == 0)
→ don't store; retry next frame. Avoids cache thrash during the
streaming-in window.
- Public InvalidateEntity(uint id) + ClearEntityCache() for explicit
invalidation hooks. Wiring (palette swap on ObjDescEvent, MeshRefs
hot-swap) is post-A.5 follow-up — for now, cache-stale entities
show their pre-swap appearance until next respawn.
Tier 2 (static/dynamic split with persistent groups) and Tier 3 (GPU
compute culling) tracked in the roadmap doc.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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