Replaces the T7-temporary default! MeshData placeholder. Streamer
now takes Func<uint, LoadedLandblock?, LandblockMeshData?> at
construction; the worker calls it after _loadLandblock succeeds and
passes the pre-built mesh into LandblockStreamResult.Loaded.
GameWindow's buildMeshOrNull factory takes the already-loaded
LoadedLandblock (lb.Heightmap is the LandBlock dat object), so no
additional dat read is needed — _heightTable and _blendCtx are
read-only after init, _surfaceCache is ConcurrentDictionary (T9).
Zero dat lock needed inside the mesh-build closure.
StreamingController._applyTerrain delegate signature widened to
Action<LoadedLandblock, LandblockMeshData> so the pre-built mesh
flows render-thread-side via the Loaded result. ApplyLoadedTerrainLocked
now accepts meshData and calls _terrain.AddLandblock directly, skipping
the per-frame LandblockMesh.Build that previously ran on the render
thread (~5ms per LB at radius=12 first traversal).
StreamingControllerTests updated: all four applyTerrain lambdas
adapted to the two-arg Action signature.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Extends the Loaded result record with a LandblockStreamTier discriminator
and a LandblockMeshData payload (default! stub — T13 wires the real
off-thread mesh build). Adds the Promoted variant for Far→Near upgrades
that only need the entity layer, not a mesh rebuild.
LandblockStreamer.HandleJob passes Tier.Near + default! MeshData at the
existing synchronous load site; StreamingControllerTests updated to
match the new positional signature.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Called once per frame from OnUpdate. Owns a StreamingRegion and uses
delegates into LandblockStreamer + a terrain-apply callback so unit
tests can inject fakes. Handles first-tick bootstrap (whole window
loads), boundary recenter (diff against previous center), and
drain completions (up to N per frame to cap GPU upload spikes).
4 new tests, all green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
