cdm/src/main/java/ucar/unidata/geoloc/projection/TransverseMercator.java
public boolean crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) {
    // either point is infinite
    if (ProjectionPointImpl.isInfinite(pt1)
            || ProjectionPointImpl.isInfinite(pt2)) {
      return true;
    }

    double y1 = pt1.getY() - falseNorthing;
    double y2 = pt2.getY() - falseNorthing;

    // opposite signed long lines
    return (y1 * y2 < 0) && (Math.abs(y1 - y2) > 2 * earthRadius);
  }
public boolean crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) {
    // either point is infinite
    if (ProjectionPointImpl.isInfinite(pt1)
            || ProjectionPointImpl.isInfinite(pt2)) {
      return true;
    }

    double y1 = pt1.getY() - falseNorthing;
    double y2 = pt2.getY() - falseNorthing;

    // opposite signed long lines
    return (y1 * y2 < 0) && (Math.abs(y1 - y2) > 2 * earthRadius);
  }
Does the line between these two points cross the projection "seam".

@param pt1 the line goes between these two points
@param pt2 the line goes between these two points
@return false if there is no seam