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hyperframes/packages/producer/tests/webgl-video-texture-render-compat/output/compiled.html
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James RussoandClaude Opus 4.8 d580f2a1d8 fix(render): make WebGL video textures deterministic in headless render (#1403)
* fix(render): make WebGL video textures deterministic in headless render

WebGL compositions that sample a `<video>` as a texture (e.g. a faceted
crystal with clips mapped onto its facets) rendered with flickering,
non-deterministic facets: a video would intermittently show a stale frame or
go black, and the same frame differed between two renders.

Two gaps caused this:

1. No WebGL analog of the WebGPU `patchVideoTextureCompat`. Chrome's headless
   compositor can't feed decoded `<video>` frames to the GPU, so the engine
   injects a decoded `<img class="__render_frame__">` sibling per video each
   frame. The WebGPU `copyExternalImageToTexture` path substitutes it, but
   `texImage2D` / `texSubImage2D` did not — so WebGL uploaded a stale/black
   frame. Add `patchWebGLVideoTextureCompat()` mirroring the WebGPU patch
   (shared `resolveRenderFrameImage` helper).

2. Capture ordering. Per frame the runtime seeks (GPU adapters render on
   `hf-seek`) BEFORE the engine injects the decoded frames, so the GPU render
   read a frame that didn't exist yet. After injecting, the engine now calls
   `window.__hfReseekGpu(t)` — a force-dispatch (`forceDispatchSeekEvent`) that
   bypasses the same-time `hf-seek` dedup — so GPU compositions re-upload their
   textures from the freshly-injected, decoded frames, deterministically.

Tests: unit tests for the texImage2D/texSubImage2D substitution and the
force-dispatch, plus a videoFrameInjector regression test asserting the
post-injection GPU reseek fires only when frames were injected. Verified
end-to-end: a WebGL prism with 8 live <video> facets renders byte-identical
across independent runs with no facet flicker.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* test(render): add producer render-compat regression for WebGL video textures

A WebGL2 canvas samples a <video> as a texture every hf-seek (the natural
author pattern, distilled from the HeyGen prism). The render-compat harness
renders it and compares against the golden: with the video-texture fix the
render reproduces the decoded frames; revert the fix and the canvas renders
black, collapsing the comparison.

Golden verified to contain real, time-varying video content (not black), so a
regression is caught rather than passing vacuously.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-12 22:37:00 -07:00

107 lines
4.0 KiB
HTML

<!DOCTYPE html>
<html>
<head><style data-hyperframes-text-rendering="true">html,body,*{text-rendering:geometricPrecision}</style>
<style>
body {
margin: 0;
background: #000;
}
[data-composition-id="webgl-video-texture-test"] {
position: relative;
overflow: hidden;
}
#gl {
position: absolute;
top: 0;
left: 0;
width: 1280px;
height: 720px;
}
/* Texture-source video: sampled into WebGL only, parked off-canvas. */
#vid {
position: absolute;
top: 0;
left: 0;
width: 4px;
height: 4px;
opacity: 0;
z-index: -1;
}
</style>
</head>
<body>
<div id="root" data-composition-id="webgl-video-texture-test" data-width="1280" data-height="720" data-start="0" data-duration="2">
<video id="vid" class="clip" data-start="0" data-duration="2" data-track-index="0" src="clip.mp4" muted playsinline data-end="2" data-has-audio="false"></video>
<canvas id="gl"></canvas>
</div>
<script>// WebGL2 textured fullscreen triangle sampling the source video element.
// The handler uploads that video as a texture on every hf-seek — the
// natural author pattern. In headless render, Chrome can't supply decoded
// video frames to WebGL, so the core video-texture patch substitutes the
// engine's injected, decoded render-frame image, and the post-injection
// GPU reseek re-runs this handler. With the fix, render reproduces the
// preview snapshot (PSNR high); without it the canvas is black (PSNR
// collapses). NB: avoid writing literal tag syntax in comments here — the
// compiler's media-attribute injection scans the raw HTML for it.
(function () {
var canvas = document.getElementById("gl");
canvas.width = 1280;
canvas.height = 720;
var gl = canvas.getContext("webgl2", { preserveDrawingBuffer: true });
if (!gl) return;
var VS =
"#version 300 es\n" +
"in vec2 p; out vec2 uv;\n" +
"void main(){ uv = vec2(p.x*0.5+0.5, 0.5-p.y*0.5); gl_Position = vec4(p,0.0,1.0); }";
var FS =
"#version 300 es\n" +
"precision highp float; in vec2 uv; uniform sampler2D tex; out vec4 c;\n" +
"void main(){ c = texture(tex, uv); }";
function sh(type, src) {
var s = gl.createShader(type);
gl.shaderSource(s, src);
gl.compileShader(s);
return s;
}
var prog = gl.createProgram();
gl.attachShader(prog, sh(gl.VERTEX_SHADER, VS));
gl.attachShader(prog, sh(gl.FRAGMENT_SHADER, FS));
gl.linkProgram(prog);
gl.useProgram(prog);
var buf = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, buf);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1, -1, 3, -1, -1, 3]), gl.STATIC_DRAW);
var loc = gl.getAttribLocation(prog, "p");
gl.enableVertexAttribArray(loc);
gl.vertexAttribPointer(loc, 2, gl.FLOAT, false, 0, 0);
var tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
var video = document.getElementById("vid");
function render() {
if (video && video.readyState >= 2) {
gl.bindTexture(gl.TEXTURE_2D, tex);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, video);
}
gl.clearColor(0, 0, 0, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.drawArrays(gl.TRIANGLES, 0, 3);
}
window.addEventListener("hf-seek", function () {
render();
});
render();
})();</script></body>
</html>