WebAssembly
Support for Rust 16-bit floating point
Openexr has support for 16-bit floating-point, 32-bit floating-point, and 32-bit integer pixels. Openexr rust uses 16f rgba color value and currently, WasmAbi doesn't support rust f16. I won't be able to build a openexr for webassembly without 16 bit floating point.
error: [E0277]: the trait bound f16: IntoWasmAbi is not satisfied
--> src/rgba.rs:9:1
|
9 | #[wasm_bindgen]
| ^^^^^^^^^^^^^^^ the trait IntoWasmAbi is not implemented for f16
|
= note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)
This may be better off as an issue on the wasm-bindgen repo.
Wasm doesn't even have a i16 scalar type (or any scalars <32 bits), so the addition of f16 directly to Wasm sounds highly unlikely to happen any time soon.
That said, 16-bit quantities are typically passed either in memory (and 16-bit loads/stores are supported) or directly in 32-bit types. This can be done for f16 too, and I suspect wasm-bindgen simply needs to support it. There's also SIMD vectors with 8 16-bit quantities that may be applicable to your situation.
If someone wishes to propose a 16-bit floating-format to WebAssembly, please file a new issue. For f16 support in wasm-bindgen, please file issues in the wasm-bindgen repository.
