computeOffset static method

Point<num> computeOffset(
  1. Point<num> from,
  2. double distance,
  3. double heading
)

Returns the Point resulting from moving a distance from an origin in the specified heading (expressed in degrees clockwise from north).

from The Point from which to start.

distance The distance to travel.

heading The heading in degrees clockwise from north.

Implementation

static Point computeOffset(Point from, double distance, double heading) {
  distance /= MathUtils.earthRadius;
  heading = toRadians(heading);
  // http://williams.best.vwh.net/avform.htm#LL
  double fromLat = toRadians(from.x);
  double fromLng = toRadians(from.y);
  double cosDistance = cos(distance);
  double sinDistance = sin(distance);
  double sinFromLat = sin(fromLat);
  double cosFromLat = cos(fromLat);
  double sinLat =
      cosDistance * sinFromLat + sinDistance * cosFromLat * cos(heading);
  double dLng = atan2(sinDistance * cosFromLat * sin(heading),
      cosDistance - sinFromLat * sinLat);
  return Point(toDegrees(asin(sinLat)), toDegrees(fromLng + dLng));
}