transform method

Point transform(Projection dest, Point point)

Implementation

Point transform(Projection dest, Point point) {
  var source = this;
  point = Point.copy(point); // make sure we don't mutate incoming point
  var shouldRemoveZ = point.z == null;

  utils.checkSanity(point);

  // Workaround for datum shifts towgs84, if either source or destination projection is not wgs84
  if (/*source.datum != null &&
      dest.datum != null &&*/
      _checkNotWGS(source, dest)) {
    var wgs84 = WGS84;
    point = source.transform(wgs84, point);
    source = wgs84;
  }
  // DGR, 2010/11/12
  if (source.axis != 'enu') {
    point = utils.adjust_axis(source, false, point);
  }
  // Transform source points to long/lat, if they aren't already.
  if (source.projName == 'longlat') {
    point = Point.withZ(
      x: point.x * consts.D2R,
      y: point.y * consts.D2R,
      z: point.z ?? 0,
    );
  } else {
    if (source.to_meter != null) {
      point = Point.withZ(
          x: point.x * source.to_meter!,
          y: point.y * source.to_meter!,
          z: point.z ?? 0.0);
    }
    point = source.inverse(point); // Convert Cartesian to longlat
  }
  if (source.from_greenwich != null) {
    point.x += source.from_greenwich!;
  }

  // Convert datums if needed, and if possible.
  point = dt.transform(source.datum, dest.datum, point);
  // Adjust for the prime meridian if necessary
  if (dest.from_greenwich != null) {
    point = Point.withZ(
      x: point.x - dest.from_greenwich!,
      y: point.y,
      z: point.z ?? 0.0,
    );
  }

  if (dest.projName == 'longlat') {
    // convert radians to decimal degrees
    point = Point.withZ(
      x: point.x * consts.R2D,
      y: point.y * consts.R2D,
      z: point.z ?? 0.0,
    );
  } else {
    // else project
    point = dest.forward(point);
    if (dest.to_meter != null) {
      point = Point.withZ(
          x: point.x / dest.to_meter!,
          y: point.y / dest.to_meter!,
          z: point.z ?? 0.0);
    }
  }

  // DGR, 2010/11/12
  if (dest.axis != 'enu') {
    point = utils.adjust_axis(dest, true, point);
  }

  if (shouldRemoveZ) {
    point.z = null;
    point.m = null;
    return point;
  } else {
    return point;
  }
}