func (writer *OsmElemWriter) NodeToSrid(node *element.Node) {
if writer.srid == 4326 {
return
}
if writer.srid != 3857 && writer.srid != 900913 {
panic("invalid srid. only 4326, 3857 and 900913 are supported")
}
node.Long, node.Lat = proj.WgsToMerc(node.Long, node.Lat)
}
func transformPolygon(p geojson.Polygon, targetSRID int) {
if targetSRID != 900913 && targetSRID != 3857 {
panic("transformation to non-4326/3856 not implemented")
}
for _, ls := range p {
for i := range ls {
ls[i].Long, ls[i].Lat = proj.WgsToMerc(ls[i].Long, ls[i].Lat)
}
}
}
func (writer *OsmElemWriter) NodesToSrid(nodes []element.Node) {
if writer.srid == 4326 {
return
}
if writer.srid != 3857 && writer.srid != 900913 {
panic("invalid srid. only 4326, 3857 and 900913 are supported")
}
for i, nd := range nodes {
nodes[i].Long, nodes[i].Lat = proj.WgsToMerc(nd.Long, nd.Lat)
}
}
func newPointFromCoords(coords []interface{}) (point, error) {
p := point{}
if len(coords) != 2 && len(coords) != 3 {
return p, errors.New("point list length not 2 or 3")
}
var ok bool
p.long, ok = coords[0].(float64)
if !ok {
return p, errors.New("invalid lon")
}
p.lat, ok = coords[1].(float64)
if !ok {
return p, errors.New("invalid lat")
}
if p.long >= -180.0 && p.long <= 180.0 && p.lat >= -90.0 && p.lat <= 90.0 {
p.long, p.lat = proj.WgsToMerc(p.long, p.lat)
}
return p, nil
}