# ispc-rs
A small library meant to be used as a build dependency with Cargo for easily
integrating [ISPC](https://ispc.github.io/) code into Rust projects.
[](https://crates.io/crates/ispc)
[](https://travis-ci.org/Twinklebear/ispc-rs)
## Documentation
Rust doc can be found [here](http://www.willusher.io/ispc-rs/ispc)
## Using ispc-rs
You'll want to add a build script to your crate (`build.rs`), tell Cargo about it and add this crate
as a build dependency.
```toml
# Cargo.toml
[package]
# ...
build = "build.rs"
[build-dependencies]
ispc = "0.1.0"
```
Now you can use `ispc` to compile your code into a static library:
```rust
extern crate ispc;
fn main() {
let ispc_files = vec!["src/simple.ispc"];
// Optional: Only re-run the build script if the ISPC files have been changed
for s in &ispc_files[..] {
println!("cargo:rerun-if-changed={}", s);
}
// Compile our ISPC library, this call will panic if building fails
ispc::compile_library("simple", &ispc_files[..]);
}
```
Running `cargo build` should now build your ISPC files into a library and link your Rust
application with it. For extra convenience the `ispc_module` macro is provided to import
bindings to the library generated with [rust-bindgen](https://github.com/crabtw/rust-bindgen)
into a module of the same name. Note that all the functions imported will be unsafe as they're
the raw C bindings to your lib.
```rust
#[macro_use]
extern crate ispc;
// Functions exported from simple will be callable under simple::*
ispc_module!(simple);
// Alternatively if the module should be public:
//ispc_module!(pub simple);
```
Some more complete examples can be found in the [examples/](examples/) folder.
## Compile-time Requirements
Both the [ISPC compiler](https://ispc.github.io/) and [libclang](http://clang.llvm.org/)
(for [rust-bindgen](https://github.com/crabtw/rust-bindgen)) must be available in your path.
### Windows Users
You'll need Visual Studio and will have to use the MSVC ABI version of Rust since ISPC
and Clang link with MSVC on Windows. For bindgen to find libclang you'll need to copy
`libclang.lib` to `clang.lib` and place it in your path.
I've also had issues with multiple definition link errors coming up when compiling multiple
ISPC files into a library on MSVC, I haven't figured out the cause yet. On Linux the repeated
symbols are defined in each object as well but the linker doesn't seem to mind.