解决粒子首位帧衔接问题

src/export/spineJsonExporter.ts

@@ -5,6 +5,7 @@ import type { SpineExportResult, SpineExportWarning, SpineJsonDocument, SpineJso
 import { downgradeSpineJsonTo38 } from './spine38JsonExporter'
 import { reduceBezierSamples, reduceNumericSamples, roundSpine, unwrapDegrees, type NumericSample } from './spineKeyframeReducer'
 import { buildWeightedTrailMesh } from './spineMeshBuilder'
+import { loopSegmentTiming } from '../core/loopSegmentTiming'
 
 type Track = { key: string; name: string; states: Array<ParticleState | null> }
 type ExportInput = { systems: ParticleSystem[]; timeline: TimelineState; settings: SpineExportSettings }
@@ -51,10 +52,7 @@ function particleDurationFrames(system: ParticleSystem, fps: number) {
   if (c.mode !== 'stream') end = delay + life
   else if (c.streamBehavior !== 'loop') end = delay + Math.max(1 / fps, Number(c.duration) || 0) + life
   else {
-    const loop = Math.max(1, Math.ceil(Number(c.loopDurationFrames) || 1)) / fps
-    if (c.generateLoopEndAnimation) end = delay + life + 1 / fps
-    else if (c.generateLoopStartAnimation) end = delay + loop * Math.max(1, Math.ceil(life / loop))
-    else end = delay + loop
+    end = delay + loopSegmentTiming(c, fps).total / fps
   }
   return Math.max(1, Math.ceil(end * fps) + 1)
 }