0.10.3: preloader + multi-scene export parity, jumpToScene rewinds

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/devtools/tests.ts

@@ -1018,6 +1018,48 @@ export function registerAllTests(): void {
       expect(r).toContain('ctx.scale(isx2,isy2)')
     })
 
+    test('runtime embeds a preloader (spinner + Promise.all) before starting the frame loop', () => {
+      // Loading big images, video metadata and audio `canplaythrough`
+      // must settle before the rAF kicks off — otherwise the first few
+      // frames stutter while the browser decodes. Structural pins:
+      // - A spinner <style> is injected.
+      // - A preloader overlay is appended.
+      // - Image/audio/video promises are awaited together.
+      // - canplaythrough is the event we wait on for audio.
+      const r = generateRuntimeScript()
+      expect(r).toContain('ruwio-spinner-style')
+      expect(r).toContain('ruwio-preloader')
+      expect(r).toContain('Promise.all')
+      expect(r).toContain('canplaythrough')
+      expect(r).toContain('preloadAudioClips')
+      expect(r).toContain('preloadBgVideos')
+    })
+
+    test('runtime honours separated position / rotation keyframes', () => {
+      // Parity regression: the editor samples separated position and
+      // rotation tracks via `sampleLayer()` when `layer.separated`;
+      // the runtime used to only look at the main keyframes array.
+      // Animations set up with Separate-toggled layers played flat
+      // in exports. Pin the helper and the per-branch merge.
+      const r = generateRuntimeScript()
+      expect(r).toContain('sampleKeyframeSet')
+      expect(r).toContain('layer.separated')
+      expect(r).toContain('layer.positionKeyframes')
+      expect(r).toContain('layer.rotationKeyframes')
+    })
+
+    test('runtime supports multi-scene switching (jumpToScene + applySceneSwitch)', () => {
+      // Exported bundles now carry the whole Project and handle
+      // jumpToScene internally. The runtime must expose a scene-
+      // switch helper and NOT fall through to the "unsupported"
+      // warning message anymore.
+      const r = generateRuntimeScript()
+      expect(r).toContain('applySceneSwitch')
+      expect(r).toContain('project.scenes')
+      expect(r).toContain('currentSceneId')
+      expect(r.indexOf('does not support multi-scene')).toBe(-1)
+    })
+
     test('runtime rangeOut falls back to scene.duration (not last keyframe)', () => {
       // Regression: the runtime used to fall back to `effectiveEnd(scene)`
       // — the time of the last keyframe — when scene.outTime was unset.
@@ -1356,6 +1398,19 @@ export function registerAllTests(): void {
       expect(s.project.activeSceneId).toBe(two.id)
     })
 
+    test('switchScene with resetPlayhead: true rewinds to the in-point', () => {
+      // Script and button jumps should restart the target scene at
+      // its in-point — otherwise chapter-like transitions play from
+      // wherever the previous scene was paused.
+      const s = makeFreshStore()
+      s.setDuration(10)
+      const two = s.addScene('Two')
+      s.setPlayhead(4.5)
+      expect(s.playhead).toBe(4.5)
+      s.switchScene(two.id, { resetPlayhead: true })
+      expect(s.playhead).toBe(0)
+    })
+
     test('switchScene leaves playback state alone — editor navigation does not force play', () => {
       // The editor treats scene-switch as a navigation gesture. The
       // fullscreen preview is the one that auto-plays on switch (via
@@ -6381,11 +6436,10 @@ export function registerAllTests(): void {
       await tick()
     })
 
-    test('a scripted jumpToScene switches the active scene and keeps playing', async () => {
-      // User-facing contract: a script track fires a scene-switch in the
-      // middle of a running timeline — the active scene flips and the
-      // timeline keeps running on the new page. All pages share
-      // duration/fps, so the playhead stays put and continues onward.
+    test('a scripted jumpToScene switches the scene, keeps playing, and rewinds to the in-point', async () => {
+      // Chapter-transition semantics: the incoming scene starts at
+      // the project's in-point no matter where the outgoing scene was
+      // paused. Keeps playback running across the switch.
       const s = makeFreshStore()
       s.setDuration(10)
       const aId = s.project.activeSceneId
@@ -6397,6 +6451,7 @@ export function registerAllTests(): void {
       s.tick(3)
       expect(s.project.activeSceneId).toBe(bId)
       expect(s.playing).toBe(true)
+      expect(s.playhead).toBe(s.playbackIn)
       await tick()
     })