wkb

encoding/wkb

This package provides encoding and decoding of WKB data. The interface is defined as:

func Marshal(geom orb.Geometry, byteOrder ...binary.ByteOrder) ([]byte, error)
func MarshalToHex(geom orb.Geometry, byteOrder ...binary.ByteOrder) (string, error)
func MustMarshal(geom orb.Geometry, byteOrder ...binary.ByteOrder) []byte
func MustMarshalToHex(geom orb.Geometry, byteOrder ...binary.ByteOrder) string

func NewEncoder(w io.Writer) *Encoder
func (e *Encoder) SetByteOrder(bo binary.ByteOrder)
func (e *Encoder) Encode(geom orb.Geometry) error

func Unmarshal(b []byte) (orb.Geometry, error)

func NewDecoder(r io.Reader) *Decoder
func (d *Decoder) Decode() (orb.Geometry, error)

Reading and Writing to a SQL database

This package provides wrappers for orb.Geometry types that implement sql.Scanner and driver.Value. For example:

row := db.QueryRow("SELECT ST_AsBinary(point_column) FROM postgis_table")

var p orb.Point
err := row.Scan(wkb.Scanner(&p))

db.Exec("INSERT INTO table (point_column) VALUES (?)", wkb.Value(p))

The column can also be wrapped in ST_AsEWKB. The SRID will be ignored.

If you don't know the type of the geometry try something like

s := wkb.Scanner(nil)
err := row.Scan(&s)

switch g := s.Geometry.(type) {
case orb.Point:
case orb.LineString:
}

Scanning directly from MySQL columns is supported. By default MySQL returns geometry data as WKB but prefixed with a 4 byte SRID. To support this, if the data is not valid WKB, the code will strip the first 4 bytes, the SRID, and try again. This works for most use cases.