Files
hyperframes/packages/shader-transitions
f84cc492de perf(engine): faster shader transitions via page-side WebGL compositing (#832)
* fix(cli): prefer puppeteer cache + numeric version sort (staff review)

Two correctness fixes from PR #821 self-review:

1. Cache priority order. Previous order was hyperframes-managed cache →
   puppeteer cache. HF cache is pinned to CHROME_VERSION (131-era) which
   lags 17+ releases behind upstream; if a user separately installed a
   newer chrome-headless-shell via @puppeteer/browsers install, the CLI
   would silently hand engine the older HF-cache binary while engine's
   own resolveHeadlessShellPath would have picked the newer one. Flip
   the priority so puppeteer cache wins, matching engine semantics.

2. Numeric (not lexicographic) version sort. `readdirSync.sort().reverse()`
   over names like `linux-148.0.7778.97` and `linux-99.0.6533.123` would
   return `linux-99...` first because character '9' outranks '1'. Parse
   each name into integer segments and compare them numerically.

Tests: add both-caches-populated and linux-148-beats-linux-99 cases.

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

* perf(engine): page-side compositing for shader transitions (opt-in spike)

Add an opt-in `--page-side-compositing` flag (CLI) backed by a new engine
config field `enablePageSideCompositing` and env var `HF_PAGE_SIDE_COMPOSITING`.
When set, SDR shader-transition compositions skip the Node-side layered blend
(the hf#677 chain) and instead run the shader inside Chrome via a page-side
WebGL canvas; the engine then captures ONE opaque RGB frame per output frame
via the existing streaming capture path.

This is the strongest non-beginFrame perf lever for Mac users, who cannot
take the beginFrame `~5×` path (Chromium structural limit, crbug.com/40656275).
Stacks on top of the hf#677 1.95× baseline.

Default OFF — existing fixture pins (byte-exact MP4 output) are preserved.
Opt-in path is intentionally PSNR-pinned, not byte-equal (WebGL is f32; Node
is f64). HDR content forces the existing layered path regardless.

Implementation:
- engine: new `EngineConfig.enablePageSideCompositing` (default false).
- producer/fileServer: new `HF_PAGE_SIDE_COMPOSITING_STUB` early-page script
  injected into the served HTML head when the flag is on.
- producer/renderOrchestrator: when the flag + no HDR + no png-sequence,
  route SDR transitions through the streaming path instead of the layered
  HDR stage.
- shader-transitions: new `engineModePageComposite.ts` installs a fullscreen
  WebGL compositor overlay and wraps `window.__hf.seek` so each seek inside
  a transition window captures both scenes via the Chromium
  `drawElementImage` API to GL textures, runs the fragment shader, and
  displays the composited result on the overlay canvas. The engine takes
  one screenshot per frame and sees the composited overlay.
- cli: new `--page-side-compositing` flag sets `HF_PAGE_SIDE_COMPOSITING=true`
  before producer load.
- scripts/page-side-compositing-smoke: bundled-CLI smoke that renders a
  representative fixture with and without the flag, validates the canary
  strings are in the shipped bundles, and writes a wall-time pair.

Determinism trade documented in the engine config doc-comment. The smoke
script enforces the bundled-CLI validation discipline from prior perf work
(see internal feedback note `validate_bundled_cli_not_dev_path`).

Runtime requirement: Chromium's `CanvasDrawElement` feature (already
enabled by the engine's `--enable-features=CanvasDrawElement` launch flag).
When the runtime feature is unavailable, the page-side installer logs a
warning and falls back to opacity-flip mode — the engine still takes the
streaming path; the transition window degrades to a hard scene swap. Vance
will validate on Mac Chrome where the feature is supported.

Co-Authored-By: Vai <vai@heygen.com>

* fix(shader-transitions): use html2canvas for page-side compositor capture

The original drawElementImage approach fails in engine render mode because
the virtual-time shim prevents Chromium from generating paint records for
cloned elements. drawElementImage requires a cached paint record from the
browser's compositor — clones created at capture time never receive one
because (a) shimmed rAFs deadlock inside the seek wrapper, (b) original
rAFs don't produce real paints under virtual-time control, and
(c) layoutsubtree canvases don't apply CSS stylesheet rules to children.

Switch scene capture to html2canvas (foreignObjectRendering: false), the
same JS-based renderer already used by the preview-mode fallback path in
capture.ts. html2canvas reads computed styles and renders via its own
canvas drawing pipeline with no dependency on the browser paint cycle.

Also fixes:
- Engine seek must return the result so Puppeteer awaits async seek
  promises (frameCapture.ts).
- GSAP opacity cache: compositor must restore scene opacity before seek,
  not after — GSAP caches inline values and skips re-writes.
- Support check gates on WebGL availability, not drawElementImage.

Perf: 15-scene shader-perf fixture (28s, 14 transitions, 30fps)
  Baseline (Node-side layered): 137s
  Page-side (html2canvas+WebGL): 33s → 4.1× speedup

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* refactor(shader-transitions): simplify review fixes for page-side compositor

- Use uploadTexture (zeroes canvas backing store after upload) to prevent
  ~2.2GB transient memory pressure across 280 html2canvas calls per render
- Add ignoreElements + stabilizeTransformedBoxShadows to html2canvas call,
  matching the preview-path capture.ts behavior
- Parallelize from/to scene captures with Promise.all
- Wrap post-capture render in try/finally so opacity is always restored
- Fix WebGL context leak in isPageSideCompositingSupported probe
- Remove dead ResolvedTransition.index field
- Export stabilizeTransformedBoxShadows from capture.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(producer): unify page-side compositing gating and Docker forwarding

Addresses three issues from staff review:

1. ignoreElements filter stripped all in-scene canvases (Chart.js, D3,
   p5.js) — narrowed to data-no-capture only since the compositor canvas
   is a body sibling never in the scene subtree.

2. Docker mode silently dropped --page-side-compositing — thread
   pageSideCompositing through DockerRenderOptions/buildDockerRunArgs
   with regression tests.

3. Fragmented gating across 4 independent sites could disagree:
   - Stub injection gated only on cfg flag (leaked into HDR/alpha)
   - Probe-created fileServer never got the stub
   - needsAlpha (WebM/MOV) not excluded from the gate
   - WebGL-unavailable fallback claimed layered path would run but
     orchestrator had already disabled it

   Fix: compute stub injection at the same site as the layered-bypass
   decision (after hasHdrContent is known), using addPreHeadScript on
   the already-running fileServer. Single predicate now gates both
   decisions, including !needsAlpha.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(engine): two-phase drawElementImage capture for page-side compositing

Replace html2canvas with native drawElementImage for scene capture in
the page-side compositor. drawElementImage reads from the browser's own
paint cache, giving pixel-identical output to the preview path.

The blocker was that cloned elements inside layoutsubtree canvases have
no cached paint record under virtual time — the compositor only paints
when explicitly triggered. Fix: split the seek+composite into two phases
with an engine-forced paint between them.

Phase 1 (seek wrapper, page-side):
  - GSAP seek positions the timeline
  - Clone FROM/TO scenes into visible layoutsubtree staging canvases
  - Set window.__hf_page_composite_pending flag

Engine paint force (frameCapture.ts):
  - Detect pending flag after seek returns
  - Fire micro Page.captureScreenshot (1x1 clip) via CDP to force the
    browser compositor to paint all visible elements including staging
    canvas children

Phase 2 (page.evaluate, page-side):
  - drawElementImage reads the now-valid paint records
  - Upload textures to WebGL, run shader, show GL overlay

Key insight: staging canvases must be visible (not opacity:0) for the
browser to paint their children. They sit at z-index:-9998, behind
the main DOM and covered by the GL overlay during transitions.

Perf: 15-scene fixture (28s, 14 transitions, 30fps):
  Baseline (Node-side layered): 137s
  html2canvas + WebGL:           33s (3.7×)
  drawElementImage + WebGL:      21s (6.6×)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(engine): optimize two-phase compositor hot path

- uploadTextureSource instead of uploadTexture: eliminates ~2.3GB of
  canvas buffer alloc/dealloc churn (persistent staging canvases don't
  need the one-shot zeroing behavior)
- Fold hasPending check into seek page.evaluate: eliminates one CDP
  round-trip per frame (~700 unnecessary IPC calls on non-transition
  frames)
- Fix renderShader error handling: on failure, leave source scenes
  visible as fallback instead of hiding both scenes + GL overlay
  (which produced black frames)
- Move mutable state declarations above resolveComposite to prevent
  TDZ risk on refactor

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(engine): staff review — staging cleanup, pending flag, beginFrame guard

- Clear staging canvas children when leaving transition window (prevents
  visible clone bleed-through on transparent compositions)
- Clear __hf_page_composite_pending on all resolveComposite exit paths
- Guard micro-screenshot paint force against beginFrame mode (CDP
  Page.captureScreenshot conflicts with beginFrame compositor control)
- Update CLI flag description: document video/canvas limitation, remove
  stale PSNR claim

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(engine): default-on page-side compositing for SDR shader transitions

Page-side compositing is now enabled by default for SDR shader-transition
renders without video content. The 6.6× speedup applies automatically —
no flag needed.

Auto-disables when:
- HDR content detected
- Alpha output (WebM/MOV/PNG-sequence)
- Composition contains <video> elements (cloneNode loses playback state)
- beginFrame capture mode (Linux headless)

Use --no-page-side-compositing to force the Node-side layered path.

Changes:
- Engine config: enablePageSideCompositing defaults to true
- CLI: flag default flipped to true; --no-page-side-compositing disables
- Orchestrator: added composition.videos.length === 0 gate
- Docker: forwards --no-page-side-compositing when explicitly disabled
- Config tests updated for new default

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(engine): support video elements on page-side compositing fast path

Three-phase capture protocol lets shader transitions render video scenes
without falling back to the slow Node-side layered pipeline:

1. Seek → compositor records transition metadata, sets pending flag
2. onBeforeCapture → video frame injector updates <img> replacements
3. prepare → cloneNode picks up current video frames, img.decode() awaits
4. micro-screenshot → forces browser to paint cloned elements
5. resolve → drawElementImage reads paint records, shader composites

Key changes:
- Remove `composition.videos.length === 0` gate from orchestrator
- Split compositor resolve into prepare (clone) + resolve (shader)
- Move onBeforeCapture before compositor prepare in frameCapture.ts
- Await img.decode() on cloned data-URI images to prevent stale frames
- Stop manipulating scene opacity in compositor (GL canvas overlay suffices)
- Add gsap.set declaration for shader-transitions ambient types
- Add video_missing_timing_attrs lint rule for <video> without id/data-start/data-end

Performance: compositions with video now render at 7.5s (6 workers) instead
of 2m38s on the layered path.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(core): auto-inject data-start on video/audio so frame extraction works without explicit attrs

The timing compiler now injects data-start="0" on <video> and <audio>
elements that lack it. This makes discoverMediaFromBrowser() find the
element (it queries video[data-start]), so the frame extraction pipeline
activates automatically. Videos "just work" without requiring authors to
add data-start, data-end, or id attributes.

Also removes the video_missing_timing_attrs lint rule — the compiler
handles the missing attributes automatically, so the lint rule would
only false-positive.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(core): add data-hf-auto-start sentinel on auto-injected video timing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(producer): add discoverVideoVisibilityFromTimeline for runtime video discovery

Seeks the GSAP timeline in Puppeteer to discover when each video's parent
scene is visible (opacity > 0). Uses coarse sampling at 100ms steps followed
by binary search refinement to frame-level precision (1/60s). Only processes
videos with the data-hf-auto-start sentinel so author-specified timing is
never overridden.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(producer): integrate runtime video visibility discovery into probe stage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(producer): trigger browser probe for auto-start videos, remove debug logging

The probe stage was skipping browser launch when composition duration was
already known, which meant discoverVideoVisibilityFromTimeline never ran.
Now needsBrowser also checks for data-hf-auto-start sentinel in compiled HTML.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(scripts): use mkdtempSync for smoke test work directory

Replaces hardcoded /tmp/hf-page-side-smoke with a unique temp directory
via mkdtempSync to resolve CodeQL "insecure temporary file" alert.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* style: format smoke test script

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: Vai <vai@heygen.com>
2026-05-15 16:23:12 -07:00
..
2026-05-14 21:54:56 -07:00

@hyperframes/shader-transitions

WebGL shader transitions for HyperFrames compositions. Renders GPU-accelerated scene-to-scene transitions using fragment shaders, driven by GSAP timelines.

Install

npm install @hyperframes/shader-transitions

Or load directly via CDN:

<script src="https://cdn.jsdelivr.net/npm/@hyperframes/shader-transitions/dist/index.global.js"></script>

Usage

import { init } from "@hyperframes/shader-transitions";

const tl = init({
  bgColor: "#0a0a0a",
  accentColor: "#ff6b2b",
  scenes: ["scene-1", "scene-2", "scene-3"],
  transitions: [
    { time: 3, shader: "domain-warp", duration: 0.8 },
    { time: 8, shader: "light-leak", duration: 0.7 },
  ],
});

The init() function pre-captures animated scene samples for every transition, composites cached samples with the selected shader during playback, and returns a GSAP timeline. Scene animations keep advancing through shader transitions without running DOM captures in the playback loop. If WebGL is unavailable, it falls back to normal timeline playback without shader compositing.

When the browser exposes Chrome's experimental CanvasDrawElement API, scene capture uses native HTML-in-canvas via drawElementImage(). Other browsers keep using the existing html2canvas fallback. You can feature-detect the native path with isHtmlInCanvasCaptureSupported().

With an existing timeline

Pass your own GSAP timeline to layer transitions onto it:

const tl = gsap.timeline({ paused: true });
// ... add your scene animations ...

init({
  bgColor: "#000",
  scenes: ["intro", "demo", "outro"],
  transitions: [
    { time: 5, shader: "cinematic-zoom" },
    { time: 12, shader: "glitch", duration: 0.5 },
  ],
  timeline: tl,
});

Available shaders

Shader Description
domain-warp Organic noise-based warp with glowing edge
ridged-burn Ridged noise burn with sparks and heat glow
whip-pan Horizontal motion blur simulating a fast camera pan
sdf-iris Circular iris wipe with glowing ring edge
ripple-waves Concentric ripple distortion radiating from center
gravitational-lens Warping gravity well with chromatic aberration
cinematic-zoom Radial zoom blur with chromatic fringing
chromatic-split RGB channel separation expanding from center
glitch Digital glitch with block displacement and scanlines
swirl-vortex Spiral rotation with noise-based warping
thermal-distortion Heat shimmer rising from the bottom
flash-through-white Flash to white then reveal the next scene
cross-warp-morph Noise-driven morph blending both scenes
light-leak Warm cinematic light leak with lens flare

API

init(config): GsapTimeline

Option Type Required Description
bgColor string yes Fallback background color (hex) for scene capture. Use the composition's body/canvas background — individual scenes set their own background-color via CSS.
accentColor string no Accent color (hex) for shader glow effects
scenes string[] yes Element IDs of each scene, in order
transitions TransitionConfig[] yes Transition definitions (see below)
timeline GsapTimeline no Existing timeline to attach transitions to
compositionId string no Override the data-composition-id for timeline registration
previewCaptureFps number no Browser preview pre-capture samples per transition second. Defaults to 30; rendering uses deterministic per-frame compositing instead.

Browser preview capture scale and transition-prep loading UI ownership are controlled by <hyperframes-player> (shader-capture-scale, shader-loading) instead of composition code. Direct non-player previews keep the built-in full-fidelity loading fallback.

Browser previews store captured transition snapshots in IndexedDB using a key derived from composition ID, scene DOM/style signatures, transition timing, capture FPS, scale, and dimensions. On refresh, matching snapshots are reloaded into WebGL textures instead of being captured again. Runtime scene or stylesheet edits mark only adjacent transition caches dirty; recapture is deferred until playback so editing stays responsive.

TransitionConfig

Option Type Default Description
time number Start time in seconds
shader ShaderName Shader name from the table above
duration number 0.7 Transition duration in seconds
ease string "power2.inOut" GSAP easing function

SHADER_NAMES

Array of all available shader name strings, useful for validation or building UIs.

import { SHADER_NAMES } from "@hyperframes/shader-transitions";
// ["domain-warp", "ridged-burn", "whip-pan", ...]

Distribution

Format File Use case
ESM dist/index.js Bundlers (Vite, webpack, etc.)
CJS dist/index.cjs Node.js / require()
IIFE dist/index.global.js <script> tag, CDN (global: HyperShader)

All formats include source maps. TypeScript definitions included.

License

MIT