simplefeatures

README

Simple Features

Simple Features is a pure Go Implementation of the OpenGIS Simple Feature Access Specification (which can be found here).

The specification describes a common access and storage model for 2-dimensional geometries. This is the same access and storage model used by libraries such as GEOS, JTS, and PostGIS.

Changelog

The changelog can be found here.

Supported Features

• Marshalling/unmarshalling:

  • WKT - Well Known Text
  • WKB - Well Known Binary (including SQL valuer/scanner)
  • GeoJSON (including GeoJSON Feature Collections)

• 3D and Measure coordinates.

• Spatial analysis:

  • Geometry validity checks
  • Boundary calculation
  • Bounding box (envelope) calculation
  • Convex Hull calculation
  • Exact equals check
  • Is Simple check
  • Intersects check
  • Length calculation
  • Closed geometry calculation
  • Ring property calculation
  • Area calculation
  • Centroid calculation

• Geometry manipulation

  • Reverse calculation
  • Pointwise transform
  • Force coordinates type (e.g. Force to 2D)

In the works

• Spatial analysis:
  • Intersection calculation
  • Point on surface calculation

Features Not Planned Yet

• SRIDs

• Spatial analysis:

  • Geometry buffering
  • Spatial equality check
  • Disjoint check
  • Touches check
  • Crosses check
  • Within check
  • Contains check
  • Overlaps check
  • Relates check

Tests

Some of the tests have a dependency on a Postgis database being available.

While the tests can be run in the usual Go way if you have Postgis set up locally, it's easier to run the tests using docker-compose:

docker-compose up --abort-on-container-exit

There are two additional suite of test suits utilising an automatically generated test corpus. The test suite test every function against every input combination exhaustively, and compare the result against a reference implementation. They take much longer to run, and are designed to be used as a final double check for correctness. They can be run using the following commands:

docker-compose -f docker-compose-postgis.yml up --abort-on-container-exit

docker-compose -f docker-compose-cmprefimpl.yml up --abort-on-container-exit