# Low-level bindings for PROJ v8.1.0
**This is a
[`*-sys`](https://doc.rust-lang.org/cargo/reference/build-scripts.html#-sys-packages)
crate; you shouldn't use its API directly.** See the
[`proj`](https://github.com/georust/proj) crate for general use.
A guide to PROJ functions can be found here:
https://proj.org/development/reference/functions.html.
By default, the crate will search for an existing `libproj` (via `PROJ v8.1.1`)
installation on your system using
[pkg-config](https://www.freedesktop.org/wiki/Software/pkg-config/).
If an acceptable installation is not found, proj-sys will attempt to build
libproj from source bundled in the crate.
## Features
- `bundled_proj` - forces building libproj from source even if an acceptable
version could be found on your system. Note that SQLite3 must be
present on your system if you wish to use this feature, and that it builds
`libproj` **without** its native network functionality; you will have to
implement your own set of callbacks if you wish to make use of them (see the
[`proj`](https://crates.io/crates/proj) crate for an example).
- `bundled_proj_tiff` - If the `bundled_proj` feature is enabled, adding the
`bundled_proj_tiff` feature will build PROJ with TIFF support. Note that
libtiff must be present on your system if you wish to use this feature.
## License
Licensed under either of
* Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.