# KTX2 texture transcoder for johnmcm.com

Used by the 3D Model Viewer (/model-viewer) to decode KTX2 (Basis Universal)
textures in compressed glTF and GLB files.

It is the [Basis Universal](https://github.com/BinomialLLC/basis_universal)
transcoder (Apache-2.0, Binomial LLC) as three.js 0.160.1 ships it in
`examples/jsm/libs/basis/`.

- `basis_transcoder.wasm` is used exactly as published.
- `basis_transcoder.js`, the Emscripten glue, is patched by `patch.mjs`: its
  embind layer compiles generated source text with `new Function`, which this
  site's Content Security Policy does not allow. The four functions that do
  that are rewritten as closures doing the same steps, as Emscripten does when
  built with `-sDYNAMIC_EXECUTION=0`. Nothing else is changed.

To rebuild, run `node wasm-src/basis/patch.mjs` from `frontend/`. It downloads
both files, checks their hashes, patches the glue and writes
`frontend/vendor/local/basis@1/`; then run `node scripts/vendor-local-lock.mjs`.