Created
January 17, 2021 13:46
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| List<LatLng> decodeEncodedPolyline(String encoded) { | |
| List<LatLng> poly = []; | |
| int index = 0, len = encoded.length; | |
| int lat = 0, lng = 0; | |
| BigInt Big0 = BigInt.from(0); | |
| BigInt Big0x1f = BigInt.from(0x1f); | |
| BigInt Big0x20 = BigInt.from(0x20); | |
| while (index < len) { | |
| int shift = 0; | |
| BigInt b, result; | |
| result = Big0; | |
| do { | |
| b = BigInt.from(encoded.codeUnitAt(index++) - 63); | |
| result |= (b & Big0x1f) << shift; | |
| shift += 5; | |
| } while (b >= Big0x20); | |
| BigInt rshifted = result >> 1; | |
| int dlat; | |
| if (result.isOdd) | |
| dlat = (~rshifted).toInt(); | |
| else | |
| dlat = rshifted.toInt(); | |
| lat += dlat; | |
| shift = 0; | |
| result = Big0; | |
| do { | |
| b = BigInt.from(encoded.codeUnitAt(index++) - 63); | |
| result |= (b & Big0x1f) << shift; | |
| shift += 5; | |
| } while (b >= Big0x20); | |
| rshifted = result >> 1; | |
| int dlng; | |
| if (result.isOdd) | |
| dlng = (~rshifted).toInt(); | |
| else | |
| dlng = rshifted.toInt(); | |
| lng += dlng; | |
| poly.add(LatLng((lat / 1E5).toDouble(), (lng / 1E5).toDouble())); | |
| } | |
| return poly; | |
| } |
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