Décodage de polylignes avec la nouvelle API Google Maps
Je trace un itinéraire entre deux points d'une carte. Je reçois les points de cette façon:
StringBuilder urlString = new StringBuilder();
urlString.append("http://maps.googleapis.com/maps/api/directions/json");
urlString.append("?origin=");// from
urlString.append(Double.toString(src.latitude));
urlString.append(",");
urlString.append(Double.toString(src.longitude));
urlString.append("&destination=");// to
urlString.append(Double.toString(dest.latitude));
urlString.append(",");
urlString.append(Double.toString(dest.longitude));
urlString.append("&sensor=false&mode=");
if (tipo != null) {
urlString.append(tipo);
}
return urlString.toString;
Je reçois la réponse de Google et récupère le JSON:
resp = new JSONObject(builder.toString());
Log.i("Location", "Contenido del kml: "+resp);
JSONArray routeObject = resp.getJSONArray("routes");
JSONObject routes = routeObject.getJSONObject(0);
JSONObject overviewPolylines = routes
.getJSONObject("overview_polyline");
String encodedString = overviewPolylines.getString("points");
ArrayList<LatLng> puntos=decodePoly(encodedString);
La réponse que je reçois de Google: (au format JSON):
Response: {"status":"OK","routes":[{"waypoint_order":[],"summary":"R-3 and A-3","bounds":{"southwest":{"lng":-3.676540000000001,"lat":40.00040000000001},"northeast":{"lng":-2.99933,"lat":40.43357}},"legs":[{"duration":{"value":3267,"text":"54 mins"},"distance":{"value":85039,"text":"85.0 km"},"end_location":{"lng":-2.99933,"lat":40.00040000000001},"start_address":"Calle del General Díaz Porlier, 91, 28006 Madrid, Spain","end_address":"Camino Veinticuatro, 2, 16400 Tarancón, Cuenca, Spain","start_location":{"lng":-3.676540000000001,"lat":40.43331000000001},"via_waypoint":[],"steps":[{"html_instructions":"Head <b>north<\/b> on <b>Calle del Gral Díaz Porlier<\/b> toward <b>Calle de Maldonado<\/b>","duration":{"value":6,"text":"1 min"},"distance":{"value":29,"text":"29 m"},"end_location":{"lng":-3.676520000000001,"lat":40.43357},"polyline":{"points":"ecxuFjamUs@C"},"travel_mode":"DRIVING","start_location":{"lng":-3.676540000000001,"lat":40.43331000000001}},{"html_instructions":"Take the 1st <b>right<\/b> onto <b>Calle de Maldonado<\/b>","duration":{"value":62,"text":"1 min"},"distance":{"value":266,"text":"0.3 km"},"end_location":{"lng":-3.6734,"lat":40.43345},"polyline":{"points":"ydxuFfamUPkG@a@JuGGk@"},"travel_mode":"DRIVING","start_location":{"lng":-3.676520000000001,"lat":40.43357}},{"html_instructions":"Take the 2nd <b>right<\/b> onto <b>Calle de Fco. Silvela<\/b>","duration":{"value":57,"text":"1 min"},"distance":{"value":245,"text":"0.2 km"},"end_location":{"lng":-3.671830000000001,"lat":40.4316},"polyline":{"points":"adxuFvmlURQl@e@zAoATSTMf@]pBeBLK"},"travel_mode":"DRIVING","start_location":{"lng":-3.6734,"lat":40.43345}},{"html_instructions":"Slight <b>right<\/b> onto <b>Calle de Francisco Silvela<\/b>","duration":{"value":51,"text":"1 min"},"distance":{"value":437,"text":"0.4 km"},"end_location":{"lng":-3.66913,"lat":40.42827},"polyline":{"points":"oxwuF|clUJADAFCbBkAjAeA`BoA^[XUPMLMFEnAeALIdBuAZUPMXS"},"travel_mode":"DRIVING","start_location":{"lng":-3.671830000000001,"lat":40.4316}},{"html_instructions":"Turn <b>right<\/b> onto <b>Pl. de Manuel Becerra<\/b>","duration":{"value":32,"text":"1 min"},"distance":{"value":154,"text":"0.2 km"},"end_location":{"lng":-3.668380000000001,"lat":40.42827},"polyline":{"points":"ucwuF`skU@?@@@@@?@@@?FBD?F@FAFAFADEDCFGDGDIBI@I@K@KAI?IAGAGAGCGCC?ACEEEIGGEICI?I?G@IBGD"},"travel_mode":"DRIVING","start_location":{"lng":-3.66913,"lat":40.42827}},{"html_instructions":"Turn <b>right<\/b> onto <b>Calle Alcala<\/b>","duration":{"value":61,"text":"1 min"},"distance":{"value":709,"text":"0.7 km"},"end_location":{"lng":-3.66107,"lat":40.43126000000001},"polyline":{"points":"ucwuFjnkUo@}A_AcCiEeLKYq@mBYq@[o@u@kB?KAQ]aAI[EQQu@Gc@QwAM_BEa@AU"},"travel_mode":"DRIVING","start_location":{"lng":-3.668380000000001,"lat":40.42827}},{"html_instructions":"Turn <b>right<\/b> onto the ramp to <b>M-30\/A-3\/A-4<\/b>","duration":{"value":44,"text":"1 min"},"distance":{"value":453,"text":"0.5 km"},"end_location":{"lng":-3.660580000000001,"lat":40.42720000000001},"polyline":{"points":"kvwuFt`jU\\CjIg@nBKD?rCOvDY"},"travel_mode":"DRIVING","start_location":{"lng":-3.66107,"lat":40.43126000000001}},{"html_instructions":"Continue straight","duration":{"value":45,"text":"1 min"},"distance":{"value":1009,"text":"1.0 km"},"end_location":{"lng":-3.659120000000001,"lat":40.41822000000001},"polyline":{"points":"_}vuFr}iUzKgBvCe@t@KvGm@hDUbAMPCZElAM|D_@^En@EjBEd@Df@DnAD"},"travel_mode":"DRIVING","start_location":{"lng":-3.660580000000001,"lat":40.42720000000001}},{"html_instructions":"Take exit <b>7B<\/b> to merge onto <b>M-23<\/b> toward <b>Vicálvaro\/R-3\/Valencia<\/b>","duration":{"value":117,"text":"2 mins"},"distance":{"value":2552,"text":"2.6 km"},"end_location":{"lng":-3.63392,"lat":40.41499},"polyline":{"points":"{duuFntiUFHB@^PDBFFFDDFDFBDDFBH@BBJ@F@H?F@H?FAH?FAF?FADAFAFCDADADEFCFEDEDEDEBEBEBGBE@G@E@G?G?EAG?GCGAGCEEGEEEEEEGEICIEIAKCKAK?K?MDgA?G?E?KJq@BODY@CBODW?C@I@AFe@F_@V{An@gED[@C?EHe@Ho@@G?A^{BjA}HF[tAiGzBwIdAcEVgApAuFr@sEF]Ju@DW?EDUHa@f@qEFo@f@iGXmHDgFCgGG{DM
Et finalement, je décode la chaîne reçue de cette façon, ce que j'ai trouvé dans de nombreuses réponses ici dans Stackoverflow:
private ArrayList<LatLng> decodePoly(String encoded) {
Log.i("Location", "String received: "+encoded);
ArrayList<LatLng> poly = new ArrayList<LatLng>();
int index = 0, len = encoded.length();
int lat = 0, lng = 0;
while (index < len) {
int b, shift = 0, result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
LatLng p = new LatLng((int) (((double) lat /1E5)* 1E6), (int) (((double) lng/1E5 * 1E6)));
poly.add(p);
}
for(int i=0;i<poly.size();i++){
Log.i("Location", "Point sent: Latitude: "+poly.get(i).latitude+" Longitude: "+poly.get(i).longitude);
}
return poly;
}
C’est là que je pense que l’erreur est, parce que je mets un pour voir les points qui sont décodés, et la réponse est quelque chose comme:
04-10 13:33:54.578: I/Location(25065): Point sent: Latitude: 90.0 Longitude: -110.0
04-10 13:33:54.578: I/Location(25065): Point sent: Latitude: 90.0 Longitude: -120.0
04-10 13:33:54.578: I/Location(25065): Point sent: Latitude: 90.0 Longitude: 100.0
04-10 13:33:54.578: I/Location(25065): Point sent: Latitude: 90.0 Longitude: 120.0
04-10 13:33:54.578: I/Location(25065): Point sent: Latitude: 90.0 Longitude: 40.0
Évidemment, ces points sont mal analysés. Le résultat est aucune ligne tracée nulle part.
Ma question est la suivante: tout le monde sait comment analyser la réponse de Google et la traduire en objets LatLng (PAS d'objets GeoPoints)?
Je vous remercie!
MODIFIER:
C'est la chaîne qui va être décodée:
04-10 13:50:51.608: I/Location(25065): String to decode: gcxuFjamUq@CPkGLwHJ}@hCuBdEeDf@SrJuHnG{Ed@Fr@q@AmAm@k@e@DaIaSiEuLqAwJ~Mw@~ZwDtZuC`FKbCVjA`ANdAs@nBw@Py@]c@oAT}DhC{PlBcM~GaY|DyS`BmPRy]yBu\UsNvAqObAuEnC}KpAqIh@gK[}NcByWXoRt@}GlDeWvFcq@nFi`@~G}\|@aDdDoLn`@}gAfe@upA`JyV|CiN~@uId@{ZyBwVkBmOwB{^AsNt@iWb@qYcCyS_DkPmAaK{@gRN{RbCkWrFgUbHmPxLsP|JwIpPwN|G}JfE}I|C_KlCsNvAwSFaQj@i]jCmXbHg\pIgSpGaLnN}P`JsHfVaNbQkHtZyIrOsCnTaCx\aA`i@b@nSRz]K`J{AxJiDfNkJjU{WbKkJpGeEpVkPpEiEzMcQjQw]nJyM~IoJ`IoKnH{NrOaWtIeJdNgNrLcPjKqOhIuI~MeJxKgErR{Cn]EjQkBjHqBfJeE|\yTlI_JvEqJxHsS|Xuc@~IeR|EiRr@kEz@sNOoL_B}Lk@mCsFgKkCoGwAsG]}N`CuO`D}GjHoHtFwC|HgBhFg@fJ}BtHaF~D_FjLqSfGqE|FcBnGEnEv@xK`BzNeAxQfAlJ{@jIwEjE}FvBuF|B{NtCsNrBgEdHiIdGuIxDoFpGkFhDaBrHyBbF[pHPlDg@jEuBnCkCtFgKjEqEfIcGpC{D|GoNdAcExAkSjBgDrCsBpDa@vHLfSAfBk@nE_F|Im`@tO_ZxCyEzJmKtHyElG_ClZeF|j@sIlQaD|EuChGkHnK{MdIsMfPwa@bDeJpD_RpFsz@nA}IrCqIrYoa@|BeGlEiYpD}HbKoRfCyKdBwUjEmo@zBkKzDyJvCeQdB}LJqGmAqQJ_Gx@uFtHkO`ImMfMmXtFySpCkXRuN]aYVoT~@}LxB{NvD{OjJaYbFsLnCcEtLoMfJyXzIiXbIiL~D_EzQcMjDeF|AcFhA_M`BkXpC_KjCsDnDeClQcHvEgElFqJfF_Jp\mWzd@k]`WkWlVy`@nOcTz`@_s@rP_ZbNkQ~Tu^jJaUhCuIpHgUrPi\zd@uq@~McQh\e]vTaU~KcF~KoGhG{KzF{HzGmDbDwBfDiEzB}GbEmTrBsHpCuFxe@oq@xb@el@tDgC`ZeJnXkHrKmB~EeB~C{A`Ce@bCUrBoAnAuGSqIn@yEhDeOrCuQ|A}EvAwFdDgAfGSrHUJ\p@Bj@_A|Ao@tCsD|C}Rj@wAdCuW~Ds]VCJw@OUpEc_@jDKbDwB
Si avec LatLng formate vous entendez la façon dont les objets LatLng sont créés, vous pouvez voir dans la méthode decodePoly. Ces objets latLng sont ajoutés aux objets PolylineOptions, et ceci est ajouté à la carte, de cette façon:
PolylineOption ruta=new PolylineOptions();
for(int i=0;i<puntos.size();i++){
ruta.add(new LatLng(puntos.get(i).latitude, puntos.get(i).longitude));
}//puntos is an array where the array returned by the decodePoly method are stored
ruta.color(Color.RED).width(7);
Polyline polygon=mapa.addPolyline(ruta);
J'ai changé le decodePoly que j'utilisais pour celui que j'ai trouvé après une longue recherche dans Google, et maintenant l'itinéraire est tracé correctement.
En changeant
LatLng p = new LatLng((int) (((double) lat /1E5)* 1E6), (int) (((double) lng/1E5 * 1E6)));
pour
LatLng p = new LatLng((((double) lat / 1E5)),(((double) lng / 1E5)));
Et fonctionne maintenant.
Pour ceux qui en ont besoin maintenant, il existe une bibliothèque open-source contenant de nombreuses informations utiles sur l'API Android de Google Maps, notamment le décodage et le codage de polylignes.
Découvrez-le sur Android Maps Utils et Android Maps Util Github . Pour le décodage et l’encodage, utilisez:
PolyUtil.decode(String encodedPath);
PolyUtil.encode(List<LatLng> path);
Pareil en Javascript
function decodePolyline(encoded) {
if (!encoded) {
return [];
}
var poly = [];
var index = 0, len = encoded.length;
var lat = 0, lng = 0;
while (index < len) {
var b, shift = 0, result = 0;
do {
b = encoded.charCodeAt(index++) - 63;
result = result | ((b & 0x1f) << shift);
shift += 5;
} while (b >= 0x20);
var dlat = (result & 1) != 0 ? ~(result >> 1) : (result >> 1);
lat += dlat;
shift = 0;
result = 0;
do {
b = encoded.charCodeAt(index++) - 63;
result = result | ((b & 0x1f) << shift);
shift += 5;
} while (b >= 0x20);
var dlng = (result & 1) != 0 ? ~(result >> 1) : (result >> 1);
lng += dlng;
var p = {
latitude: lat / 1e5,
longitude: lng / 1e5,
};
poly.Push(p);
}
return poly;
}
Cette méthode est utile pour décoder une polyligne
private List<LatLng> decodePoly(String encoded) {
List<LatLng> poly = new ArrayList<>();
int index = 0, len = encoded.length();
int lat = 0, lng = 0;
while (index < len) {
int b, shift = 0, result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do {
b = encoded.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
LatLng p = new LatLng((((double) lat / 1E5)),
(((double) lng / 1E5)));
poly.add(p);
}
return poly;
}
Voici comment je vais obtenir polyligne
JSONObject poly = route.getJSONObject("overview_polyline");
String polyline = poly.getString("points");
polyLineList = decodePoly(polyline);
Même chose en Pascal (Delphi):
var lat,lon,lat_f,lon_f:Double;
var index:Integer;
var len:Integer;
var b:Integer;
var shift:Integer;
var result:Integer;
var encoded:String;
var dlat:Integer;
var dlng:Integer;
encoded:='ibgqGq}ycIMvM';
len:= Length(encoded);
lat:=0;
lon:=0;
While (index <=len) do
begin
b:=$20;
shift:=0;
result:=0;
While (b >= $20) do
begin
b:=ord(encoded[index]);
b:=b-63;
index:= index+1;
result:= result OR (b AND $1f) Shl shift;
shift:=shift + 5;
end;
If (result And 1) <> 0 Then
dlat:= Not (result Shr 1)
Else
dlat:= result Shr 1;
lat:=lat+dlat;
shift:= 0;
result:= 0;
b:=$20;
While (b >= $20) do
begin
b:=ord(encoded[index]);
b:=b-63;
index:= index+1;
result:= result OR (b AND $1f) Shl shift;
shift:=shift + 5;
end;
If (result And 1) <> 0 Then
dlng:= Not (result Shr 1)
Else
dlng:= result Shr 1;
lon:=lon+dlng;
{ The coordinates of the point are used for our purposes }
lon_f:=lon/100000.0;
lat_f:=lat/100000.0;
end; //while
Voici l'implémentation dans iOS, pour tous les curieux, entièrement basée sur la réponse de @ Fustigador, mais convertie en iOS. Notez que je n'ai pas formaté le code en conséquence. J'ai ajouté quelques variables uniquement pour retourner l'objet promis.
- (GMSPath *)decodedPolylinePathFromEncodedPolylineString:(NSString *)encodedPolylineString {
NSString *decodedPolylineString = @"";
GMSMutablePath *decodedPolylinePath = [GMSMutablePath new];
CLLocationCoordinate2D decodedCoordinate;
CLLocationDegrees latitude, longitude;
int index = 0;
NSUInteger len = encodedPolylineString.length;
int lat = 0, lng = 0;
while (index < len) {
int b, shift = 0, result = 0;
do {
b = [encodedPolylineString characterAtIndex:index++] - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do {
b = [encodedPolylineString characterAtIndex:index++] - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
latitude = (((double) lat / 1E5));
longitude = (((double) lng / 1E5));
decodedCoordinate = CLLocationCoordinate2DMake(latitude, longitude);
decodedPolylineString = [NSString stringWithFormat:@"%f%f", latitude, longitude];
;
NSLog(@"%@",decodedPolylineString);
[decodedPolylinePath addCoordinate:decodedCoordinate];
}
return decodedPolylinePath;
}