@Test
public void testNeighbourLocationCode() {
// set up corner case
hash.bits = 0xc400000000000000l;
hash.significantBits = 7;
long[] lonBits = hash.getRightAlignedLongitudeBits();
assertEquals(0x8, lonBits[0]);
assertEquals(4, lonBits[1]);
long[] latBits = hash.getRightAlignedLatitudeBits();
assertEquals(0x5, latBits[0]);
assertEquals(3, latBits[1]);
GeoHash north = hash.getNorthernNeighbour();
assertEquals(0xd000000000000000l, north.bits);
assertEquals(7, north.significantBits);
GeoHash south = hash.getSouthernNeighbour();
assertEquals(0xc000000000000000l, south.bits);
assertEquals(7, south.significantBits());
GeoHash east = hash.getEasternNeighbour();
assertEquals(0xc600000000000000l, east.bits);
// NOTE: this is actually a corner case!
GeoHash west = hash.getWesternNeighbour();
assertEquals(0x6e00000000000000l, west.bits);
// NOTE: and now, for the most extreme corner case in 7-bit geohash-land
hash.bits = 0xfe00000000000000l;
east = hash.getEasternNeighbour();
assertEquals(0x5400000000000000l, east.bits);
}
@Test
public void testKnownNeighbouringHashes() {
GeoHash h1 = GeoHash.fromGeohashString("u1pb");
assertEquals("u0zz", h1.getSouthernNeighbour().toBase32());
assertEquals("u1pc", h1.getNorthernNeighbour().toBase32());
assertEquals("u300", h1.getEasternNeighbour().toBase32());
assertEquals("u302", h1.getEasternNeighbour().getEasternNeighbour().toBase32());
assertEquals("u1p8", h1.getWesternNeighbour().toBase32());
assertEquals("sp2j", GeoHash.withCharacterPrecision(41.7, 0.08, 4).toBase32());
}
private void checkMovingInCircle(double latitude, double longitude) {
GeoHash start;
GeoHash end;
start = GeoHash.withCharacterPrecision(latitude, longitude, 12);
end = start.getEasternNeighbour();
end = end.getSouthernNeighbour();
end = end.getWesternNeighbour();
end = end.getNorthernNeighbour();
assertEquals(start, end);
assertEquals(start.getBoundingBox(), end.getBoundingBox());
}