perf(driver): render WebGL via Mesa llvmpipe

[Kikobeats]

Swap the SwiftShader fallback for ANGLE -> system GL (--use-angle=gl), which resolves to Mesa llvmpipe. On GPU-less hosts this renders WebGL ~4x faster (measured ~7s vs ~30s for a 3D chart).

Requires Mesa (libgl1-mesa-dri) and an X display (Xvfb) so ANGLE can bind a GL surface; without one, WebGL silently falls back to a 2D view. Drops --disable-gpu/--in-process-gpu, which force SwiftShader and kill the GL surface respectively.

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Note

Medium Risk
Default browser launch behavior changes for all consumers: headless Linux without Mesa/Xvfb may get weaker WebGL or 2D fallbacks instead of SwiftShader, while CI and local dev assumptions shift.

Overview
Switches default Chromium launch flags from the SwiftShader stack (--disable-gpu, --use-angle=swiftshader, --in-process-gpu) to --use-angle=gl, routing WebGL through ANGLE → system OpenGL (Mesa llvmpipe on GPU-less Linux) for much faster software WebGL. Comments in driver.js document that Mesa and a display (e.g. Xvfb) are required so ANGLE can bind a GL surface.

CI (main.yml, pull_request.yml) conditionally ensures libgl1-mesa-dri is present and runs tests under xvfb-run.

Tests stop asserting brittle chrome://gpu strings or exact SwiftShader renderer text. They now check live WebGL/WebGL2 via ANGLE (no SwiftShader), with CI-only checks for Mesa llvmpipe. Screencast tests await start(), use waitUntil: 'load', and animate the page until at least one frame is captured under the GL compositor. screenshot drops the unused cheerio devDependency.

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[coveralls]

Coverage is 87.597% — webgl into master. No base build found for master.

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

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[cursor]

Unpinned Mesa pinned OpenGL

Medium Severity

The new pinned WebGL renderer test normalizes the LLVM segment but requires an exact OpenGL 4.5 suffix, while CI installs unpinned libgl1-mesa-dri from apt. When the runner’s Mesa build advertises a different GL version or profile text, the test can fail without any repository change.

Additional Locations (2)

• .github/workflows/main.yml#L68-L70
• .github/workflows/pull_request.yml#L42-L44

 

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