@Override
    public boolean start(final int ilonStart, final int ilatStart, final int ilonTarget, final int ilatTarget) {
        if (islandPairs.size() > 0) {
            final long n1 = ((long) ilonStart) << 32 | ilatStart;
            final long n2 = ((long) ilonTarget) << 32 | ilatTarget;
            if (islandPairs.hasPair(n1, n2)) {
                return false;
            }
        }
        lonStart = ilonStart;
        lonLast = lonStart;
        latStart = ilatStart;
        latLast = latStart;
        lonTarget = ilonTarget;
        latTarget = ilatTarget;
        anyUpdate = false;
        return true;
    }
the WaypointMatcher is feeded by the decoder with geoemtries of ways that are
already check for allowed access according to the current routing profile
<p>
It matches these geometries against the list of waypoints to find the best
match for each waypoint
main/src/main/java/cgeo/geocaching/brouter/mapaccess/WaypointMatcherImpl.java