# Vendored DS4 Metal boundary

The Metal bridge and GPU declarations track the DS4 boundary audited at commit
`ec7642cdd9ec81d01ad4b1fd8f8a3d1511533748` (2026-08-31):

- `ds4_metal.m`
- `ds4_gpu.h`

The matching Metal kernels, including `glm53_*.metal`, live in the
repository-level `metal/` directory. The other headers remain DS4Server-owned
interfaces and are not copies of DS4 application code.
DS4Server builds and bundles this local snapshot; it does not read a sibling
DS4 checkout. Rust owns the model, graph, session, sampling, and lifecycle.
Objective-C remains only at the platform Metal boundary.