geometry-proj

Coordinate-reference-system reprojection for the geometry kernel, backed by the pure-Rust proj4rs engine — no C dependency.

Boost.Geometry leaves projections to its unsupported extensions/gis/projections/; this crate provides them:

use geometry_proj::{reproject, Crs};

let wgs84 = Crs::from_epsg(4326)?;      // lon/lat in radians
let mercator = Crs::from_epsg(3857)?;   // metres
reproject(&mut geometry, &wgs84, &mercator)?;

Build a Crs from a proj4 string, an EPSG code, or a WKT definition (parsed by proj4wkt). reproject transforms any point / linestring / ring / polygon / multipolygon in place.

Geographic coordinates are carried in radians, matching proj4rs.