rust-geo-validator

A trait for MultiPolygon/Polygon geo-types to check for validity according to OGC standards. Validation currently conforms only partially to those rules.

Validation Traits

The current geo/geo-types packages contain no support for validation of Geometries other then succeeding/failing to create a Geometry. This package adds a trait to the MultiPolygon and Polygon type to check for validity according to the OGC specifications (currently a work in progress).

The validation function provided here look for violations of the following rules:

• A polygon may not have less than three points
• A polygon may not have any unclosed rings
• No ring in the polygon may intersect another ring
• No ring in the polygon may intersect itself
• No point on a ring may be touching a line in it or any other ring
• No points may be repeated in a ring
• All points must have valid floating point values

validate()

The is_valid() trait will return false at the first error and provides no debugging information.

Examples

```rust use geotypes::polygon; use geovalidator::Validate;

// Polygon self intersects and has intersecting inner/outer rings let poly = polygon!( exterior: [ (x: 0., y: 0.), (x: 0., y: 200.), (x: 200., y: 0.), (x: 200., y: 200.), ], interiors: [ [ (x: 10., y: 20.), (x: 50., y: 20.), (x: 20., y: 50.), (x: 50., y: 50.), ], ], );

let valid = poly.validate(); assert_eq!(valid, false); ```

validate_detailed

The validate_detailed() function collects information about where the current MultiPolygon/Polygon is invalid, and returns that information to the caller.

Examples

```rust use geotypes::polygon; use geovalidator::Validate;

// Polygon self intersects and has intersecting inner/outer rings let poly = polygon!( exterior: [ (x: 0., y: 0.), (x: 0., y: 200.), (x: 200., y: 0.), (x: 200., y: 200.), ], interiors: [ [ (x: 10., y: 20.), (x: 50., y: 20.), (x: 20., y: 50.), (x: 50., y: 50.), ], ], );

let valid = poly.validatedetailed(); asserteq!(valid.valid, false); asserteq!(valid.ringintersectsotherring.len(), 3); asserteq!(valid.selfintersections.len(), 2); asserteq!(valid.pointtouching_line.len(), 1);

asserteq!(valid.ringintersectsotherring[0].x, 20f64); asserteq!(valid.ringintersectsotherring[0].y, 20f64); asserteq!(valid.ringintersectsotherring[1].x, 35f64); asserteq!(valid.ringintersectsotherring[1].y, 35f64); asserteq!(valid.ringintersectsotherring[2].x, 50f64); asserteq!(valid.ringintersectsotherring[2].y, 50f64);

asserteq!(valid.selfintersections[0].x, 100f64); asserteq!(valid.selfintersections[0].y, 100f64); asserteq!(valid.selfintersections[1].x, 32.857142857142854f64); asserteq!(valid.selfintersections[1].y, 37.142857142857146f64);

asserteq!(valid.pointtouchingline[0].x, 50f64); asserteq!(valid.pointtouchingline[0].y, 50f64); ```