ParticleRenderer.Draw is called up to ~11 times per frame (sky pre/post,
scene, per-visible-cell, dynamics, unattached passes). Each call
allocated a fresh List<ParticleDraw> (BuildDrawList) and a fresh
List<ParticleInstance> (the per-batch `run` list), and ParticleSystem.
EnumerateLive was a `yield return` iterator block - a heap-allocated
state machine allocated fresh on every Draw call regardless of particle
count.
Fix: reuse _drawListScratch/_runScratch fields (Clear() + refill) on
ParticleRenderer. Replace EnumerateLive's iterator with a struct
enumerable/enumerator pair (ParticleSystem.LiveParticleEnumerable): the
foreach fast path uses the struct enumerator directly (zero allocation),
while LINQ/test callers (.ToList(), .Single(), etc.) still work via the
explicit IEnumerable<T> interface implementation, which falls back to a
boxed iterator only when that surface is used - those call sites are
test-only, not the per-frame render path this task targets.
Verified safe: all 11 Draw() call sites in GameWindow.cs are plain
synchronous invocations from the single-threaded OnRender chain (no
Task.Run/Parallel dispatch), and each call fully drains its lists
before returning - no call ever overlaps another's use of the reused
buffers. Per-cell filtering semantics unchanged (same predicate, same
traversal order).
dotnet build clean, dotnet test 4120 passed / 4 skipped (unchanged).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Ports retail's ParticleEmitterInfo / Particle::Init / Particle::Update
(0x005170d0..0x0051d400) and PhysicsScript runtime to a C# data-layer
plus a Silk.NET billboard renderer. Sky-PES path is debug-only behind
ACDREAM_ENABLE_SKY_PES because named-retail decomp confirms GameSky
copies SkyObject.pes_id but never reads it (CreateDeletePhysicsObjects
0x005073c0, MakeObject 0x00506ee0, UseTime 0x005075b0).
Post-review fixes folded into this commit:
H1: AttachLocal (is_parent_local=1) follows live parent each frame.
ParticleSystem.UpdateEmitterAnchor + ParticleHookSink.UpdateEntityAnchor
let the owning subsystem refresh AnchorPos every tick — matches
ParticleEmitter::UpdateParticles 0x0051d2d4 which re-reads the live
parent frame when is_parent_local != 0. Drops the renderer-side
cameraOffset hack that only worked when the parent was the camera.
H3: Strip the long stale comment in GfxObjMesh.cs that contradicted the
retail-faithful (1 - translucency) opacity formula. The code was
right; the comment was a leftover from an earlier hypothesis and
would have invited a wrong "fix".
M1: SkyRenderer tracks textures whose wrap mode it set to ClampToEdge
and restores them to Repeat at end-of-pass, so non-sky renderers
that share the GL handle can't silently inherit clamped wrap state.
M2: Post-scene Z-offset (-120m) only fires when the SkyObject is
weather-flagged AND bit 0x08 is clear, matching retail
GameSky::UpdatePosition 0x00506dd0. The old code applied it to
every post-scene object — a no-op today (every Dereth post-scene
entry happens to be weather-flagged) but a future post-scene-only
sun rim would have been pushed below the camera.
M4: ParticleSystem.EmitterDied event lets ParticleHookSink prune dead
handles from the per-entity tracking dictionaries, fixing a slow
leak where naturally-expired emitters' handles stayed in the
ConcurrentBag forever during long sessions.
M5: SkyPesEntityId moves the post-scene flag bit to 0x08000000 so it
can't ever overlap the object-index range. Synthetic IDs stay in
the reserved 0xFxxxxxxx space.
New tests (ParticleSystemTests + ParticleHookSinkTests):
- UpdateEmitterAnchor_AttachLocal_ParticlePositionFollowsLiveAnchor
- UpdateEmitterAnchor_AttachLocalCleared_ParticleFrozenAtSpawnOrigin
- EmitterDied_FiresOncePerHandle_AfterAllParticlesExpire
- Birthrate_PerSec_EmitsOnePerTickWhenIntervalElapsed (retail-faithful
single-emit-per-frame behavior)
- UpdateEntityAnchor_WithAttachLocal_MovesParticleToLiveAnchor
- EmitterDied_PrunesPerEntityHandleTracking
dotnet build green, dotnet test green: 695 / 393 / 243 = 1331 passed
(up from 1325).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
