spatial

Add simple types to use PostGIS with any database driver in golang. Point and NullPoint types. Json marshalling and unmarshalling supported for nullable structs. SQL Boiler support for NullPoint

Types supported

• geometry(Geometry,4326)

Usage with database

First define your struct:

package main

type TripEvent struct {
  Geo spatial.Point `db:"geo" json:"geo"`
}

func main() {
  path := []spatial.Point{}
  err := database.DB.
  	Select("geo").
  	From("trip_events").
  	QueryStructs(&path)

  if err != nil {
    panic(err)
  }

  // Encode the path with .000000 level of precision
  polyline := spatial.Encode(path, 6)
  fmt.Println(polyline) // _p~iF~ps|U_ulLnnqC_mqNvxq`@

  points := spatial.Decode(polyline, 6)
  fmt.Println(polyline) // make(map[]spatial.Point, 2)
}

If your users aren't going to be zooming you can ignore the level 6 precision and go with 5 to get the best compression.

Usage without database

First define your struct:

package main

func main() {
  path := []spatial.Point{
    spatial.Point{
      Lat: 38.889803,
      Lng: -77.009114,
    },
    spatial.Point{
      Lat: 38.889810,
      Lng: -77.009124,
    },
  }

  // Encode the path with .000000 level of precision
  polyline := spatial.Encode(path, 6)
  fmt.Println(polyline) // _p~iF~ps|U_ulLnnqC_mqNvxq`@

  points := spatial.Decode(polyline, 6)
  fmt.Println(polyline) // make(map[]spatial.Point, 2)
}