Struct CrsTransformer 

pub struct CrsTransformer { /* private fields */ }

Transformer for coordinate reference system conversions

When the crs-transform feature is enabled, this uses the oxigdal-proj backend (pure-Rust proj4rs) for arbitrary CRS pairs. The two hardcoded paths (WGS84↔Web Mercator) are kept as a fallback so that the API behaves identically when the feature is disabled.

Area-of-use handling

A point that lies outside the source CRS’s declared area of use is handled according to CrsTransformer’s OutOfAreaPolicy (default OutOfAreaPolicy::PassThrough). See CrsTransformer::with_out_of_area_policy and CrsTransformer::transform_coordinates_reporting.

Implementations

impl CrsTransformer

pub fn new( source_crs: impl Into<String>, target_crs: impl Into<String>, ) -> Result<Self>

Creates a new CRS transformer

Arguments

• source_crs - Source CRS (e.g., “EPSG:4326”)
• target_crs - Target CRS (e.g., “EPSG:3857”)

Returns

A new transformer

Errors

Returns error if CRS definitions are invalid

pub fn with_out_of_area_policy(self, policy: OutOfAreaPolicy) -> Self

Sets the policy for coordinates outside the source CRS’s area of use.

Returns self for builder-style chaining. Under OutOfAreaPolicy::Error, the proj backend (when the crs-transform feature is enabled) is rebuilt with strict area-of-use validation so that out-of-area points are actually detected and surfaced as errors rather than silently transformed or passed through.

pub fn out_of_area_policy(&self) -> OutOfAreaPolicy

Returns the currently configured OutOfAreaPolicy.

pub fn from_common(source: CommonCrs, target: CommonCrs) -> Result<Self>

Creates a transformer from common CRS types

pub fn transform_coordinate(&self, coord: &Coordinate) -> Result<Coordinate>

Transforms a single coordinate

Arguments

• coord - Input coordinate in source CRS

Returns

Transformed coordinate in target CRS

Area of use

When the crs-transform feature is enabled, a point that lies outside the source CRS’s declared area of use is handled per the configured OutOfAreaPolicy (see Self::with_out_of_area_policy). Under the default OutOfAreaPolicy::PassThrough such a point is returned unchanged in the source CRS (with a debug-level log); under OutOfAreaPolicy::Error it produces an error. To transform a whole geometry and learn which vertices fell out of area without aborting, use Self::transform_coordinates_reporting.

Errors

Returns error if transformation fails, or if a coordinate is outside the area of use and the policy is OutOfAreaPolicy::Error.

pub fn transform_coordinates( &self, coords: &[Coordinate], ) -> Result<Vec<Coordinate>>

Transforms multiple coordinates efficiently

pub fn transform_coordinates_reporting( &self, coords: &[Coordinate], ) -> Result<(Vec<Coordinate>, Vec<usize>)>

Transforms multiple coordinates, reporting the indices of any that fell outside the source CRS’s area of use (and were passed through unchanged).

This lets callers detect and reject/filter a geometry that would otherwise silently mix coordinate systems, without switching to the hard-error OutOfAreaPolicy::Error. The returned index list is always empty unless the crs-transform feature is active and the current policy is OutOfAreaPolicy::PassThrough.

Errors

Propagates any transformation error (including out-of-area errors when the policy is OutOfAreaPolicy::Error).

pub fn transform_point(&self, point: &Point) -> Result<Point>

Transforms a point

pub fn transform_linestring( &self, linestring: &LineString, ) -> Result<LineString>

Transforms a linestring

pub fn transform_polygon(&self, polygon: &Polygon) -> Result<Polygon>

Transforms a polygon

pub fn transform_geometry(&self, geometry: &Geometry) -> Result<Geometry>

Transforms a geometry