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Rust and WebGPU struct layouts can diverge in shared buffers

mattkeeter.com 6 min read Editor score 8/10

The example writes a Rust struct directly into a WebGPU buffer, but the host and shader have different layout rules; failures in compute-shader VMs can leave threads spinning until reboot. Engineers sharing data across CPU and GPU code need to account for those layout mismatches.

What

Facet is used to test whether Rust data layouts match the layouts expected by WebGPU shaders.

How

It parses WGSL with naga and compares shader member offsets with Rust field offsets; a mat3x3 example exposed padding differences.

Why it matters

These checks can catch buffer-layout mismatches that otherwise cause incorrect GPU data or hard-to-debug compute failures.

Read on mattkeeter.com → Hacker News · 6 comments

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