fix decoding encoreding

encoding/polylines/encoding.go

@@ -5,12 +5,79 @@ import (
 	"github.com/twpayne/go-polyline"
 )
 
-func Encode(line orb.LineString) string {
+// // Encode encodes coordinates to the "Encoded Polyline Algorithm Format"
+// // More info: https://developers.google.com/maps/documentation/utilities/polylinealgorithm
+// // points: points of the polyline
+// // precision: usually 5 or 6; Google's original algorithm uses 5 digits of decimal precision,
+// // which is accurate to about a meter. A precision of 6 gives you an accuracy of about 10cm
+// // more info: https://mapzen.com/blog/polyline-precision/
+// func Encode(linestring orb.LineString, precision uint32) string {
+
+// 	encoded := ""
+
+// 	latitude := 0.0
+// 	longitude := 0.0
+
+// 	for _, point := range linestring {
+// 		polyLatitude := encodeElement(point.Lat()-latitude, precision)
+// 		encoded += polyLatitude
+
+// 		polyLongitude := encodeElement(point.Lon()-longitude, precision)
+// 		encoded += polyLongitude
+
+// 		// to conserve space, points only include the offset from the previous point
+// 		latitude = point.Lat()
+// 		longitude = point.Lon()
+
+// 	}
+
+// 	return encoded
+
+// }
+
+// // Encode5 is a short call for Encode with precision set to 5
+// // Accuracy is about one meter
+// func Encode5(linestring orb.LineString) string {
+// 	return Encode(linestring, 5)
+// }
+
+// // Encode6 is a short call for Encode with precision set to 6
+// // Accuracy is about ten centimeters
+// func Encode6(linestring orb.LineString) string {
+// 	return Encode(linestring, 6)
+// }
+
+// // encodeElement encodes an coordinate element (i.e. latitude or longitude)
+// // to the "Encoded Polyline Algorithm Format"
+// func encodeElement(element float64, precision uint32) string {
+
+// 	elementInt := int32(math.Round(element * math.Pow10(int(precision))))
+// 	elementInt = elementInt << 1
+// 	if element < 0 {
+// 		elementInt = ^elementInt
+// 	}
+
+// 	var c chunks
+// 	c.Parse(elementInt)
+
+// 	return c.String()
+
+// }
+
+// // round n to precision digits
+// func round(n float64, precision uint32) float64 {
+
+// 	factor := math.Pow10(int(precision))
+// 	return math.Round(n*factor) / factor
+
+// }
+
+func Encode(line orb.LineString, precision uint32) string {
 
 	preparedLine := [][]float64{}
 
 	for _, point := range line {
-		preparedLine = append(preparedLine, []float64{point.Lon(), point.Lat()})
+		preparedLine = append(preparedLine, []float64{point.Lat(), point.Lon()})
 	}
 
 	return string(polyline.EncodeCoords(preparedLine))