Struct proj::Proj

pub struct Proj { /* fields omitted */ }

A PROJ instance

Methods

impl Proj

pub fn new(definition: &str) -> Option<Proj>

Try to instantiate a new PROJ instance

Note: for projection operations, definition specifies the output projection; input coordinates are assumed to be geodetic in radians, unless an inverse projection is intended.

For conversion operations, definition defines input, output, and any intermediate steps that are required. See the convert example for more details.

Safety

This method contains unsafe code.

pub fn new_known_crs(from: &str, to: &str, area: Option<Area>) -> Option<Proj>

Create a transformation object that is a pipeline between two known coordinate reference systems. from and to can be:

• an "AUTHORITY:CODE", like "EPSG:25832". When using that syntax for a source CRS, the created pipeline will expect that the values passed to project() or convert() respect the axis order and axis unit of the official definition ( so for example, for EPSG:4326, with latitude first and longitude next, in degrees). Similarly, when using that syntax for a target CRS, output values will be emitted according to the official definition of this CRS.
• a PROJ string, like "+proj=longlat +datum=WGS84". When using that syntax, the axis order and unit for geographic CRS will be longitude, latitude, and the unit degrees.
• the name of a CRS as found in the PROJ database, e.g "WGS84", "NAD27", etc.
• more generally, any string accepted by new()

If you wish to alter the particular area of use, you may do so using area_set_bbox()

 extern crate proj;
 use proj::Proj;

 extern crate geo_types;
 use geo_types::Point;

 let from = "EPSG:2230";
 let to = "EPSG:26946";
 let nad_ft_to_m = Proj::new_known_crs(&from, &to, None).unwrap();
 let result = nad_ft_to_m
     .convert(Point::new(4760096.421921f64, 3744293.729449f64))
     .unwrap();
 assert_approx_eq!(result.x(), 1450880.29f64, 1.0e-2);
 assert_approx_eq!(result.y(), 1141263.01f64, 1.0e-2);

Safety

This method contains unsafe code.

pub fn area_set_bbox(&mut self, new_area: Option<Area>)

Set the bounding box of the area of use

This bounding box will be used to specify the area of use for the choice of relevant coordinate operations. In the case of an area of use crossing the antimeridian (longitude +/- 180 degrees), west must be greater than east.

Safety

This method contains unsafe code.

pub fn def(&self) -> String

Get the current definition from PROJ

Safety

This method contains unsafe code.

pub fn project<T>(
    &self,
    point: Point<T>,
    inverse: bool
) -> Result<Point<T>, Error> where
    T: Float, 

Project geodetic Point coordinates (in radians) into the projection specified by definition

Note: specifying inverse as true carries out an inverse projection to geodetic coordinates (in radians) from the projection specified by definition.

Safety

This method contains unsafe code.

pub fn convert<T>(&self, point: Point<T>) -> Result<Point<T>, Error> where
    T: Float, 

Convert Point coordinates using the PROJ pipeline operator

This method makes use of the pipeline functionality available since v5.0.0, which differs significantly from the v4.x series

It has the advantage of being able to chain an arbitrary combination of projection, conversion, and transformation steps, allowing for extremely complex operations.

The following example converts from NAD83 US Survey Feet (EPSG 2230) to NAD83 Metres (EPSG 26946) Note the steps:

• 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.

extern crate proj;
use proj::Proj;

extern crate geo_types;
use geo_types::Point;

let nad_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
").unwrap();
let result = nad_ft_to_m.convert(Point::new(4760096.421921f64, 3744293.729449f64)).unwrap();
assert_approx_eq!(result.x(), 1450880.29f64, 1.0e-2);
assert_approx_eq!(result.y(), 1141263.01f64, 1.0e-2);

Safety

This method contains unsafe code.

pub fn convert_array<'a, T>(
    &self,
    points: &'a mut [Point<T>]
) -> Result<&'a mut [Point<T>], Error> where
    T: Float, 

Convert a mutable slice (or anything that can deref into a mutable slice) of Point coordinates
The following example converts from NAD83 US Survey Feet (EPSG 2230) to NAD83 Metres (EPSG 26946)

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 mut v = vec![Point::new(4760096.421921, 3744293.729449), Point::new(4760197.421921, 3744394.729449)];
ft_to_m.convert_array(&mut v);
assert_approx_eq!(v[0].x(), 1450880.2910605003f64);
assert_approx_eq!(v[1].y(), 1141293.7960220212f64);

Safety

This method contains unsafe code.

Trait Implementations

impl Drop for Proj

fn drop(&mut self)

Executes the destructor for this type.