private FolderType createMarks(KmlRoute route, int startIndex, int endIndex) { ObjectFactory objectFactory = new ObjectFactory(); FolderType marks = objectFactory.createFolderType(); marks.setName(MARKS); marks.setVisibility(FALSE); marks.setOpen(FALSE); double currentDistance = 0, previousDistance = 0; int currentKiloMeter = 1; List<KmlPosition> positions = route.getPositions(); for (int i = startIndex + 1; i < endIndex; i++) { KmlPosition previousPosition = positions.get(i - 1); KmlPosition currentPosition = positions.get(i); Double distance = currentPosition.calculateDistance(previousPosition); if (isEmpty(distance)) continue; currentDistance += distance; if (currentDistance >= METERS_BETWEEN_MARKS) { // calculate the point at the kilometer mark that's between the current position and the // previous one. // it is possible, that there's more than one point to create // see: http://www.movable-type.co.uk/scripts/latlong.html and // http://williams.best.vwh.net/avform.htm#LL KmlPosition intermediate = new KmlPosition( previousPosition.getLongitude(), previousPosition.getLatitude(), null, null, null, null); // remaining distance between the last point and the mark double remainingDistance = METERS_BETWEEN_MARKS - (previousDistance % METERS_BETWEEN_MARKS); do { double angle = toRadians(intermediate.calculateAngle(currentPosition)); double latitude1 = toRadians(intermediate.getLatitude()); double longitude1 = toRadians(intermediate.getLongitude()); double latitude2 = asin( sin(latitude1) * cos(remainingDistance / EARTH_RADIUS) + cos(latitude1) * sin(remainingDistance / EARTH_RADIUS) * cos(angle)); double longitude2 = longitude1 + atan2( sin(angle) * sin(remainingDistance / EARTH_RADIUS) * cos(latitude1), cos(remainingDistance / EARTH_RADIUS) - sin(latitude1) * sin(latitude2)); intermediate.setLatitude(toDegrees(latitude2)); intermediate.setLongitude(toDegrees(longitude2)); PlacemarkType placeMark = createMark( currentKiloMeter++, intermediate.getLongitude(), intermediate.getLatitude()); marks.getAbstractFeatureGroup().add(objectFactory.createPlacemark(placeMark)); remainingDistance = METERS_BETWEEN_MARKS; } while (toDouble(intermediate.calculateDistance(currentPosition)) > METERS_BETWEEN_MARKS); currentDistance = currentDistance % METERS_BETWEEN_MARKS; } previousDistance = currentDistance; } return marks; }