Scroll-driven animation conversion
- apply() writes nothing per frame on the supported path; the hero
squeeze, fade line and header curves all ride scroll-driven animations
on the compositor.
- Section boundaries flip via IntersectionObserver sentinels; the scroll
listener is gone from the hot path.
- The scrollbar thumb rides its own scroll-driven animation.
- @supports-not fallback keeps the previous rAF --p path verbatim, so
unsupported engines render identically.
- Curves verified exact to 1e-6 against the old path, 0.000px continuity
across boundary flips, correct retarget on resize.
Perf fixes
- Forced-layout reads pulled out of both scroll handlers.
- Resize settle-reflow: a second reflow 200ms after resize quiesces, and
the pane is observed too. This was the root cause of the fullscreen
fade-wedge and of the long-standing intermittent where rows stayed
hidden after a resize.
Glass
- backdrop-filter removed from chips and preview surfaces.
- Bar glass blur 20 -> 12.
- Choose-hero pill removed from the UI; pickArtistHero/clearArtistHero
backend is untouched and the control can be re-homed later.
Hero design (final)
- Crossfade twins are permanent. Twin blur is baked via bakeBlur()
(clamp-to-edge pad -> blur -> crop) so the frames stay pixel-aligned
with no edge fringe and no geometry scaling.
- Bloom strip retired everywhere; HeroGpuCanvas's internal bloom canvases
are hidden by one scoped rule and the component is unchanged.
- Seam is a pure mirror: the artwork's top strip flipped inside the glass
band, clipped at the bar's top line, riding the squeeze with the hero
and dissolving in lockstep on rotation.
- GPU twin overlay crossfades on rotation instead of snapping — the
incoming baked frame fades in on hero-banner-in with a 2-frame cap.
- ~930 lines of experimental variants and the perf-flag system deleted;
the surviving path is a pixel no-op against the approved configuration.
Debug overlay
- PERF/SEAM rows dropped; the overlay keeps stats plus an FPS/drops/worst
counter (Ctrl+Shift+D).
The content fade mask on .scrollbody lives in the scrolling element's local
box, so its cut stop (--flow-cut) must ride scroll to stay at a fixed screen
line. Driving that from heroScroll's rAF lagged the native compositor scroll
by a frame on fast flicks, so the cut slid up and rows briefly showed above
where they should clip (user-reported).
Move --flow-cut to a CSS scroll-driven animation (@property + @keyframes +
animation-timeline: scroll(nearest block), @supports-gated), so it's a pure
function of scroll position evaluated on the compositor and can't lag. The
keyframe delta and animation-range share one oversized constant (100000px)
so the value is base + scrollTop for ANY scroll distance — necessary because
the artist page changes its own content height as it scrolls, making the
total range non-constant. apply() keeps the per-frame path only as the
unsupported-engine fallback.
Verified live: screen cut constant at 217px across scrollTop 300..2500,
--flow-cut == base+scrollTop exactly.
Preview modal audio, five rounds:
- True track-change crossfade: scheduleSettle no longer silences the
outgoing clip at t=0; preview_load's equal-power fade owns both ramps,
gated on the incoming voice's first Playing event (audible_marks), with
failure/overstay fallbacks. CROSSFADE_MS = 340 — locked to the reel's
card-slide so audio and visuals land together.
- Two-neighbour lease prefetch + a 15-min on-disk clip byte-cache
(recent_clips): steps in BOTH directions crossfade in ~15 ms; revisits
never re-download.
- Adaptive settle (isolated steps fire immediately, bursts coalesce) and
anticipatory auto-advance (step at clip end minus 400 ms) so auto-play
crossfades over the tail instead of gapping.
- Session resume memory: revisited tracks continue where they left off
(decoder-level start offset via play_local_from/resume_at); finished
tracks restart from the top.
- Open/close crossfades with the MAIN player: fade-pause with the
desired-paused latch landing at ramp end, fade-resume from the paused
position; MAIN_FADE_GEN guards; focus handshake relaxation documented
in focusBridge.
Volume normalization (Settings > Playback, default on):
- Dependency-free BS.1770/EBU R128 meter in the player crate (K-weighting,
400 ms gated blocks, incremental) + analyzer that reads the same growing
file playback streams from — first plays are measured at download speed.
- Gain layered under user volume; audible start GATED on a preliminary
measurement (10 s of audio or 800 ms budget) so the level is right from
the first sample and never changes mid-track; prelim boosts capped 3 dB,
peak-aware clipping guard, persistent loudness-cache.json.
- Gapless boundaries get their own sample-accurate gain via
SetNextNormGainDb, fed by preload analysis.
Debug overlay (Ctrl+Shift+D): process-tree CPU / PDH GPU / working-set +
private-commit RAM / network rates / FPS / current-track download progress
read from the backend's own StreamProgress / live normalization state /
preview session phase. Polls only while visible.
131 JS + player + app tests green; every path verified live over CDP.
Working:
- PreviewOverlay.svelte mounted at app root; opens over a fixture manifest
(window.__previewFixture(n) in dev), inert background, player bar hidden,
focus trap, keyboard nav, F3 rail, T3 swaps, R1b capsule, accent extraction.
- previewSession.svelte.js: store + service wiring (production + fixture).
- Root integration in App.svelte; revision-gateway bumps + notePlaybackGeneration
threaded through state.svelte.js player entry points; api.win guarded so plain
vite browser mounts.
- Launcher on the artist page builds a real artist manifest and opens the modal
with a play-full starter.
- 70 JS tests still green.
Two bugs found and fixed during bring-up:
- effect_update_depth_exceeded: bleed-crossfade and bump effects read AND wrote
the same $state; wrapped writes in untrack(). This loop was breaking Svelte's
scheduler globally (even ui.* stopped reacting).
- accentFromImage now sets crossOrigin for remote covers.
KNOWN BROKEN (handoff): reel vertical centering. The active card stays centred
at index 0 but drifts by one stride per step. Root cause isolated — see
TODO-Feature-Docs/scrollable-track-previews/HANDOFF-PHASE2C.md.
The previous .git directory was found gutted (only info/ remained), so
history is unrecoverable locally. This commit restores version control
with the tree exactly as it stands: the working app, the preview-tracks
launcher on the artist hero, the scrollable-track-previews design bundle
(docs + approved mockups), and the Phase 0 validation artifacts.