# The `tectonic_pdf_io` crate
[](https://crates.io/crates/tectonic_pdf_io)
This crate is part of [the Tectonic
project](https://tectonic-typesetting.github.io/en-US/). It provides the PDF,
XDV, and image I/O capabilities of [XeTeX]’s `xdvipdfmx` as a crate, *currently
providing only a C API*.
[XeTeX]: http://xetex.sourceforge.net/
- [API documentation](https://docs.rs/tectonic_pdf_io/).
- [Main Git repository](https://github.com/tectonic-typesetting/tectonic/).
This crate depends on [libpng], which it attempts to find externally using
[pkg-config] or [vcpkg]. It should be possible to create another “bridge” crate
so that this external dependency could be avoided, but this hasn’t been done
yet.
[libpng]: http://www.libpng.org/pub/png/libpng.html
[pkg-config]: https://www.freedesktop.org/wiki/Software/pkg-config/
[vcpkg]: https://github.com/microsoft/vcpkg
If your project depends on this crate, Cargo will export for your build script
an environment variable named `DEP_TECTONIC_PDF_IO_INCLUDE_PATH`, which will be
a semicolon-separated list of directories enabling your code to include the
`dpx-*.h` headers.
You will need to ensure that your Rust code actually references this crate in
order for the linker to include linked libraries. A `use` statement will
suffice:
```rust
#[allow(unused_imports)]
#[allow(clippy::single_component_path_imports)]
use tectonic_pdf_io;
```
## Cargo features
This crate currently provides no [Cargo features][features].
[features]: https://doc.rust-lang.org/cargo/reference/features.html