Files
Next-Location/app/src/main/java/com/a1/nextlocation/json/GeometryDecoder.java
Sem van der Hoeven c68bbd4062 ctrl alt L
2021-01-06 21:19:06 +01:00

60 lines
1.7 KiB
Java

package com.a1.nextlocation.json;
import com.google.gson.JsonArray;
/**
* source: https://github.com/GIScience/openrouteservice-docs#geometry-decoding
*/
public class GeometryDecoder {
public static JsonArray decodeGeometry(String encodedGeometry, boolean inclElevation) {
JsonArray geometry = new JsonArray();
int len = encodedGeometry.length();
int index = 0;
int lat = 0;
int lng = 0;
int ele = 0;
while (index < len) {
int result = 1;
int shift = 0;
int b;
do {
b = encodedGeometry.charAt(index++) - 63 - 1;
result += b << shift;
shift += 5;
} while (b >= 0x1f);
lat += (result & 1) != 0 ? ~(result >> 1) : (result >> 1);
result = 1;
shift = 0;
do {
b = encodedGeometry.charAt(index++) - 63 - 1;
result += b << shift;
shift += 5;
} while (b >= 0x1f);
lng += (result & 1) != 0 ? ~(result >> 1) : (result >> 1);
if (inclElevation) {
result = 1;
shift = 0;
do {
b = encodedGeometry.charAt(index++) - 63 - 1;
result += b << shift;
shift += 5;
} while (b >= 0x1f);
ele += (result & 1) != 0 ? ~(result >> 1) : (result >> 1);
}
JsonArray location = new JsonArray();
location.add(lat / 1E5);
location.add(lng / 1E5);
if (inclElevation) {
location.add((float) (ele / 100));
}
geometry.add(location);
}
return geometry;
}
}