# `🌋 ash-molten`
**Statically link with [MoltenVK]**
[](https://embark.dev)
[](https://discord.gg/dAuKfZS)
[](https://crates.io/crates/ash-molten)
[](https://docs.rs/ash-molten)
[](https://deps.rs/repo/github/EmbarkStudios/ash-molten)
[](https://github.com/EmbarkStudios/ash-molten/actions)
`ash-molten` is built on top of [ash] and exposes a new entry point to statically link with [MoltenVK].
Requires Xcode 14 and Mac OS 10.15 (Catalina) to compile.
## Why?
* You want to compile down to a single binary that doesn't need any environment variables to bet set.
* You just want to try out [MoltenVK] without needing to setup the SDK.
## Why not?
* [ash] already supports [MoltenVK] via runtime linking. Runtime linking is the preferred way of using Vulkan because the loader can be updated at anytime without needing to recompile.
* `ash-molten` doesn't have access to the validation layers and therefore can not output any debug information.
## How?
```rust
let entry = ash_molten::MoltenEntry::load().expect("Unable to load Molten");
let app_name = CString::new("Hello Static Molten").unwrap();
let appinfo = vk::ApplicationInfo::builder()
.application_name(&app_name)
.application_version(0)
.engine_name(&app_name)
.engine_version(0)
.api_version(vk_make_version!(1, 0, 0));
let create_info = vk::InstanceCreateInfo::builder().application_info(&appinfo);
let instance = entry.create_instance(&create_info, None).expect("Instance");
let devices = instance.enumerate_physical_devices();
println!("{:?}", devices);
```
You can run the example with `cargo run`.
## How does it work?
`ash-molten` links statically with [MoltenVK], it then uses `vkGetInstanceProcAddr` to resolve all the function pointers at runtime.
### Features
`cargo build` will clone a specific release of [MoltenVK] compile and statically link it with your application.
`cargo build --features pre-built` will download a pre-built version of MoltenVK from a release of ash-molten.
`cargo build --features external` provide own MoltenVK library.
If you want to compile [MoltenVK] yourself, you can use the `external` feature. `cargo build --features external` requires `libMoltenVK` to be visible (`LD_LIBRARY_PATH`).
### How to update
To update the version of [MoltenVK] uses, change the following:
* In `build.rs`, change `static VERSION = "1.1.0"` to the new [MoltenVK release](https://github.com/KhronosGroup/MoltenVK/releases) tag name
* Update the crate version in `Cargo.toml`
* Bump the patch version
* Set the version metadata to the MoltenVK release.
* E.g. `0.2.0+1.1.9` -> `0.2.1+1.1.10`.
* Before you can submit the PR, you must also update the prebuilt version. See the next section.
### Updating pre-built version
To update the prebuilt version of MoltenVK that ash-molten uses, change the following:
* Follow the steps mentioned above.
* Download the MoltenVK XCFramework from, for example, the Vulkan SDK for Mac or build [MoltenVK] yourself.
* in the case of downloading it from an external source make sure MoltenVK version matches `static VERSION`.
* From the XCFramework folder, from the built version of MoltenVK, zip the folders of platforms that need to be supported individually.
* Create a release with the tag: MoltenVK-{version number}.
* Upload the zip files to the release with the MoltenVK-{version number} tag.
## Contributing
[](CODE_OF_CONDUCT.md)
We welcome community contributions to this project.
Please read our [Contributor Guide](CONTRIBUTING.md) for more information on how to get started.
## License
Licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or )
* MIT license ([LICENSE-MIT](LICENSE-MIT) or )
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed as above, without any additional terms or
conditions.
[MoltenVK]: https://github.com/KhronosGroup/MoltenVK
[ash]: https://github.com/MaikKlein/ash