Crate geonative_proj 

geonative-proj

Pure-Rust projection engine for the geonative geospatial library. No PROJ, no C dep — every projection is implemented from scratch.

What v0.1 covers

• EPSG:4326 ↔ EPSG:3857 — spherical Web Mercator
• WGS84/UTM zones 1–60 N+S (EPSG:32601–32760)
• GDA2020/MGA zones 46–59 (EPSG:7846–7859) — Transverse Mercator on GRS80 ellipsoid, southern-hemisphere false-northing
• EPSG:7844 ≡ EPSG:4326 for v0.1 (treated as identity; ~1.5 m visualisation-grade caveat — full Helmert 7-param transform is v0.2)

Two projected CRSes (e.g. MGA-55 → WGS84/UTM-54) automatically pipe through 4326.

Accuracy

• Web Mercator is exact per the spherical-Mercator definition.
• TM (UTM/MGA) uses Krüger n-series, 6th order — sub-millimetre accuracy out to ±4° from the central meridian (well past the standard ±3° zone half-width).

Usage

use geonative_proj::Transformer;
use geonative_core::Coord;

let t = Transformer::from_epsg(7855, 4326)?;   // Vicmap MGA Zone 55 → WGS84
let mut c = Coord::xy(500000.0, 5800000.0);
t.transform(&mut c)?;
// c.x ≈ 147.0 (central meridian), c.y ≈ -37.95

How it composes with the rest of the stack

geonative-convert’s pipeline picks up a Transformer from the --to-crs flag and applies transform_geometry to each feature mid-stream — one method call per feature, no allocation.

Re-exports

pub use ellipsoid::Ellipsoid;

pub use ellipsoid::GRS80;

pub use ellipsoid::WGS84;

pub use error::ProjError;

pub use error::Result;

pub use transformer::Transformer;

Modules

ellipsoid

Reference ellipsoid parameters.

epsg

EPSG code → projection parameters lookup.

error

Projection-engine error type.

spherical_mercator

EPSG:4326 ↔ EPSG:3857 — spherical Web Mercator.

tm

Ellipsoidal Transverse Mercator via the Krüger n-series (6th order).

transformer

The Transformer handle — constructed once, applied to many coords.

Constants

VERSION