PROJ

High-level Rust bindings for the latest stable version of PROJ (7.1.x), compatible with the Georust ecosystem. Includes network grid download functionality.

Requirements

By default, this crate depends on a pre-built libproj, accessed by the proj-sys crate: if PROJ v7.1.x is present on your system and can be located by the build script, it will be used. As a fallback, libproj will be built from source. While this crate may be backwards-compatible with older PROJ 7 and PROJ 6 versions, this is neither tested nor supported.

Feature Flags

• pkg_config: enables the use of pkg-config when linking against libproj — note that pkg-config must be available on your system. This feature and bundled_proj are mutually exclusive.
• bundled_proj: builds libproj from source bundled in the proj-sys crate. Note that this feature requires Sqlite3 and libtiff to be present on your system. This feature and bundled_proj are mutually exclusive.
• network: exposes APIs which, when enabled, can fetch grid data from the internet to improve projection accuracy. See enable_network for details.

Examples

Convert from NAD 83 US Survey Feet to NAD 83 Meters Using EPSG Codes

use proj::Proj;

extern crate geo_types;
use geo_types::Point;

let from = "EPSG:2230";
let to = "EPSG:26946";
let ft_to_m = Proj::new_known_crs(&from, &to, None).unwrap();
let result = ft_to_m
    .convert(Point::new(4760096.421921, 3744293.729449))
    .unwrap();
assert_approx_eq!(result.x() as f64, 1450880.2910605003);
assert_approx_eq!(result.y() as f64, 1141263.0111604529);

Note that as of v5.0.0, PROJ uses the pipeline operator, which allows an arbitrary number of steps in a conversion. The example below works as follows:

• define the operation as a pipeline operation
• define step 1 as an inverse transform, yielding geodetic coordinates
• define step 2 as a forward transform to projected coordinates, yielding metres.

Convert from NAD 83 US Survey Feet to NAD 83 Meters Using the pipeline Operator

use proj::Proj;

extern crate geo_types;
use geo_types::Point;

let ft_to_m = Proj::new("
    +proj=pipeline
    +step +inv +proj=lcc +lat_1=33.88333333333333
    +lat_2=32.78333333333333 +lat_0=32.16666666666666
    +lon_0=-116.25 +x_0=2000000.0001016 +y_0=500000.0001016001 +ellps=GRS80
    +towgs84=0,0,0,0,0,0,0 +units=us-ft +no_defs
    +step +proj=lcc +lat_1=33.88333333333333 +lat_2=32.78333333333333 +lat_0=32.16666666666666
    +lon_0=-116.25 +x_0=2000000 +y_0=500000
    +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
", false).unwrap();
// The Presidio, approximately
let result = ft_to_m.convert(Point::new(4760096.421921, 3744293.729449)).unwrap();
assert_eq!(result.x(), 1450880.29);
assert_eq!(result.y(), 1141263.01);

Inverse Projection from Stereo70 to Geodetic

use proj::Proj;

extern crate geo_types;
use geo_types::Point;

// Carry out an inverse projection from Pulkovo 1942(58) / Stereo70 (EPSG 3844)
// into geodetic lon and lat coordinates (in radians)
let stereo70 = Proj::new("
    +proj=sterea +lat_0=46 +lon_0=25 +k=0.99975 +x_0=500000 +y_0=500000
    +ellps=krass +towgs84=33.4,-146.6,-76.3,-0.359,-0.053,0.844,-0.84
    +units=m +no_defs
    ").unwrap();
let rp = stereo70.project(
    Point::new(500119.70352012233, 500027.77896348457), true
).unwrap();
assert_eq!(rp, Point::new(0.436332, 0.802851));

Bulk Transformations

The Proj::convert_array() and Proj::project_array()methods are available for bulk conversions. Both accept mutable slices (or anything that can Deref to a mutable slice) of Point<T: Float> or Into<Point<T: Float> elements.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.