* refactor(engine,producer): adopt requestPaint contract, retire autoAlpha rewrite
crbug 529829538 was closed "working as intended": the html-in-canvas API's
contract is mutate -> canvas.requestPaint() -> await the canvas paint event ->
drawElementImage, which refreshes the subtree's paint records including
compositor-applied properties. Verified on the pinned 151 floor and 152
canary: root opacity, root filter, nested group opacity, and child transforms
(incl. will-change-promoted) all capture exactly; the root element's own
TRANSFORM is the one property still never baked.
- Paint invalidation: all three paint-wait sites (serial capture, worker
produce, batch produce) now call canvas.requestPaint() when available and
fall back to the __hf_de_tick sentinel background toggle on builds without
it. The 250ms unsynchronized-draw safety net is unchanged.
- Root-opacity ratio correction REMOVED (all three draw sites + base-opacity
recording at injection). Since 151 the paint wait bakes current root opacity
into the snapshot as pixel alpha, so the ratio correction DOUBLE-APPLIED
animated root fades: a root-fade A/B tripped the runtime self-verify at
30.1dB (frame 24, ~0.92 expected vs ~0.85 rendered). Post-removal the same
comp self-verifies at inf and matches the screenshot render at PSNR=inf.
The root TRANSFORM correction stays — verified still required.
- autoAlpha rewrite machinery DELETED: the opt-in opacity->autoAlpha tween
rewrite (default-off since the retraction fix; measured ~28dB damage on
comps whose fades it touched), its flush-time transparent-target hiding,
the __HF_FAST_CAPTURE_AUTOALPHA__ flag plumbing, and the deferral-time
retract/re-assert dance. The stub keeps tween-target tracking (3D
projection + at-risk scans depend on it).
Validation: canary suite 7/7 with PSNRs identical to baseline (58.30 /
43.13 / 54.15 dB); root-fade A/B PSNR=inf vs screenshot; engine suite 905
passed (1 pre-existing color-grading failure); tsc/oxlint/oxfmt clean.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* fix(engine,producer): review fixes — gate opacity correction by paint mechanism
Max code-review findings on the requestPaint adoption:
- Root-opacity ratio correction RESTORED, gated per frame on how the paint
was produced: it applies on BeginFrame (sync=false) captures and on builds
without canvas.requestPaint() — the two paths where the snapshot holds the
root's load-time opacity — and is skipped only on requestPaint-driven
paints, where the snapshot bakes the current opacity and the ratio
double-applies (the proven 30.1dB root-fade failure). Base opacity is
recorded at injection again.
- Invalidation extracted to a page-scope helper (__hfDeInvalidate, installed
by injectDrawElementCanvas) shared by all three paint-wait sites: sentinel
toggle ALWAYS (a paint is guaranteed even if requestPaint elides one on a
clean subtree) + requestPaint() in a try/catch (a throwing implementation
degrades to sentinel-only instead of rejecting the capture). Returns
whether requestPaint ran, feeding the opacity-correction gate. Also removes
the triplicated inline block and its three anonymous `as T` casts.
- HF_FAST_CAPTURE_AUTOALPHA now logs a retirement warning instead of being a
silent no-op (the deleted rewrite's comment documented it as an operator
escape hatch).
- Batch producer docstring updated (still described the tick-toggle-only
paint wait); stub tween observer reshaped to a void fn (observeTweenCall)
so no arg-rewriting seam survives.
Validation: canary suite 7/7 (58.30/43.13/54.15dB, d95f20b6 clean);
root-fade A/B self-verify 4x inf + whole-video PSNR=inf; engine suite 905
passed (1 pre-existing); tsc/oxlint/oxfmt clean; stub regenerated.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---------
Co-authored-by: WaterrrForever <miao.yang@heygen.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Amortizes per-frame CDP protocol overhead (~3.5-9ms/frame) by looping
seek -> paint-wait -> drawElementImage -> createImageBitmap in ONE
page.evaluate for runs of consecutive frames; bitmaps still post to the
encode worker per frame. Validated on 19 stratified DE comps: median
1.20x on top of worker-encode (to 1.56x), zero damaged frames, edge
comps (static-dedup-heavy, clip-cut) bit-identical; mid-batch failure
re-captures via the per-frame path (screenshot-fallback semantics
preserved). Off by default; opt in with HF_DE_BATCH=4.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
* feat(engine): drawElementImage capture service
* chore(ci): ignore drawElementService exports pending upstack consumers
Fallow's per-PR audit diffs against the merge base, so the bottom of the
fast-capture stack (#1917) sees drawElementService's exports as unused —
their consumers (frameCapture) land in #1919, two PRs upstack. ignoreExports
entry documents this and can be dropped once #1919 merges.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
