feat(vfx): bind effects to live animated poses

src/AcDream.Core/Vfx/ParticleSystem.cs

@@ -75,6 +75,31 @@ public sealed class ParticleSystem : IParticleSystem
         return SpawnEmitter(desc, anchor, rot, attachedObjectId, attachedPartIndex, renderPass);
     }
 
+    public bool TrySpawnEmitterById(
+        uint emitterId,
+        Vector3 anchor,
+        Quaternion? rot,
+        uint attachedObjectId,
+        int attachedPartIndex,
+        ParticleRenderPass renderPass,
+        out int handle)
+    {
+        if (!_registry.TryGet(emitterId, out EmitterDesc? desc))
+        {
+            handle = 0;
+            return false;
+        }
+
+        handle = SpawnEmitter(
+            desc,
+            anchor,
+            rot,
+            attachedObjectId,
+            attachedPartIndex,
+            renderPass);
+        return true;
+    }
+
     public void PlayScript(uint scriptId, uint targetObjectId, float modifier = 1f)
     {
         // Full PhysicsScript scheduling lives in PhysicsScriptRunner.
@@ -90,6 +115,12 @@ public sealed class ParticleSystem : IParticleSystem
         {
             for (int i = 0; i < em.Particles.Length; i++)
                 em.Particles[i].Alive = false;
+            // Retail DestroyParticleEmitter removes the table entry now; it
+            // does not wait for the next update. This is also required for a
+            // hard-stopped emitter whose cell-less simulation is paused.
+            _byHandle.Remove(handle);
+            _handleOrder.Remove(handle);
+            EmitterDied?.Invoke(handle);
         }
     }
 
@@ -107,10 +138,50 @@ public sealed class ParticleSystem : IParticleSystem
         if (!_byHandle.TryGetValue(handle, out var em))
             return;
         em.AnchorPos = anchor;
+        if (!em.SimulationEnabled)
+            em.LastEmitOffset = anchor;
         if (rot.HasValue)
             em.AnchorRot = rot.Value;
     }
 
+    /// <summary>
+    /// Changes only render presentation. Logical lifetime is unaffected.
+    /// </summary>
+    public void SetEmitterPresentationVisible(int handle, bool visible)
+    {
+        if (_byHandle.TryGetValue(handle, out ParticleEmitter? emitter))
+            emitter.PresentationVisible = visible;
+    }
+
+    /// <summary>
+    /// Applies retail's in-cell update gate without ending emitter ownership.
+    /// Retail retains absolute creation timestamps while cell-less; the next
+    /// update observes the elapsed wall-clock interval and expires old state.
+    /// Only acdream's legacy rate accumulator is rebased to prevent a synthetic
+    /// multi-particle catch-up burst that retail's one-shot emission path lacks.
+    /// </summary>
+    public void SetEmitterSimulationEnabled(int handle, bool enabled)
+    {
+        if (!_byHandle.TryGetValue(handle, out ParticleEmitter? emitter)
+            || emitter.SimulationEnabled == enabled)
+        {
+            return;
+        }
+
+        if (!enabled)
+        {
+            emitter.SimulationEnabled = false;
+            return;
+        }
+
+        if (emitter.Desc.Birthrate <= 0f && emitter.Desc.EmitRate > 0f)
+        {
+            emitter.LastEmitTime = _time;
+            emitter.EmittedAccumulator = 0f;
+        }
+        emitter.SimulationEnabled = true;
+    }
+
     /// <summary>True when the given handle still maps to a live emitter.</summary>
     public bool IsEmitterAlive(int handle) => _byHandle.ContainsKey(handle);
 
@@ -136,6 +207,8 @@ public sealed class ParticleSystem : IParticleSystem
             int handle = _handleOrder[i];
             if (!_byHandle.TryGetValue(handle, out var em))
                 continue;
+            if (!em.SimulationEnabled)
+                continue;
 
             AdvanceEmitter(em);
             int live = CountAlive(em);