The central runtime for every client-visible scripted effect server
triggers via PlayScript (opcode 0xF754) — spell casts, emote
gestures, combat flinches, AND lightning flashes during storms.
Previously acdream parsed PhysicsScript from the dat (via DRW) but
had no runner; the PlayScript stub in ParticleSystem.cs was a
no-op.
Decompile provenance (`docs/research/2026-04-23-physicsscript.md`,
`docs/research/2026-04-23-lightning-real.md`):
FUN_0051bed0 — play_script(scriptId) public API — resolves the
dat id, queues into the owner's ScriptManager list.
FUN_0051be40 — ScriptManager::Start — alloc 16-byte node
{startTime, script*, next}.
FUN_0051bf20 — advance one hook, schedule next fire by next
hook's StartTime.
FUN_0051bfb0 — per-frame tick: while head.NextHookAbsTime ≤
globalClock, fire via vtable dispatch.
Port choices:
- Flat List<ActiveScript> vs retail linked list — iteration is
simpler, N is small.
- Scripts keyed by (scriptId, entityId) — replay replaces instead
of stacking, matches retail's "play_script on the same obj
doesn't double-schedule".
- Anchor world pos cached at Play() time — good enough for
short-lived effects (lightning, spell casts). Callers that
need fresh positions for long emote animations can Play()
again each frame (idempotent).
- Constructor takes Func<uint, PhysicsScript?> resolver so tests
don't need DatCollection; production uses the DatCollection
overload that wraps Get<PhysicsScript> with null-on-fail.
- CallPESHook recurses Play() with Pause baked into the
sub-script's StartTimeAbs. Matches retail semantics where
nested scripts fire on the NEXT tick (list iteration order).
Diag: ACDREAM_DUMP_PLAYSCRIPT=1 logs every Play() and every fire as
[pes] lines. Use this to identify the actual script IDs your ACE
server is sending so we can confirm the lightning pipeline when the
server sends a strike.
Test coverage (9 new tests, all passing):
- unknown script returns false, zero id silent-ignore
- hooks fire in order at their scheduled times
- entityId + anchor pass through to sink
- replay same (scriptId, entityId) replaces, doesn't stack
- different entities run independently
- StopAllForEntity cancels that entity's scripts only
- CallPES nested spawn semantics (fires next tick)
- CallPES with Pause delays correctly
No GameWindow wiring yet — Phase 6b handles the 0xF754 packet
handler and Phase 6c plugs the runner into the frame loop.
Build + 742 tests green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
