/// <summary>
///
/// </summary>
/// <param name="points"></param>
/// <param name="source"></param>
/// <param name="dest"></param>
/// <param name="startIndex"></param>
/// <param name="numPoints"></param>
public static void ReprojectPoints(double[] xy, double[] z, ProjectionInfo source, ProjectionInfo dest, int startIndex, int numPoints)
{
double toMeter = source.Unit.Meters;
// Geocentric coordinates are centered at the core of the earth. Z is up toward the north pole.
// The X axis goes from the center of the earth through greenwich.
// The Y axis passes through 90E.
// This section converts from geocentric coordinates to geodetic ones if necessary.
if (source.IsGeocentric)
{
if (z == null)
{
throw new ProjectionException(45);
}
for (int i = startIndex; i < numPoints; i++)
{
if(toMeter != 1)
{
xy[i * 2] *= toMeter;
xy[i * 2 + 1] *= toMeter;
}
}
GeocentricGeodetic g = new GeocentricGeodetic(source.GeographicInfo.Datum.Spheroid);
g.GeocentricToGeodetic(xy, z, startIndex, numPoints);
}
// Transform source points to lam/phi if they are not already
ConvertToLatLon(source, xy, startIndex, numPoints);
double fromGreenwich = source.GeographicInfo.Meridian.Longitude * source.GeographicInfo.Unit.Radians;
if(fromGreenwich != 0)
{
for (int i = startIndex; i < numPoints; i++)
{
if (xy[2* i] != double.PositiveInfinity)
xy[2 * i] += fromGreenwich;
}
}
// DATUM TRANSFORM IF NEEDED
if(!source.GeographicInfo.Datum.Matches(dest.GeographicInfo.Datum))
{
DatumTransform(source, dest, xy, z, startIndex, numPoints);
}
// Adjust to new prime meridian if there is one in the destination cs
fromGreenwich = dest.GeographicInfo.Meridian.Longitude*dest.GeographicInfo.Unit.Radians;
if(fromGreenwich != 0)
{
for(int i = startIndex; i < numPoints; i++)
{
if(xy[i * 2] != double.PositiveInfinity)
{
xy[i * 2 +1] -= fromGreenwich;
}
}
}
if(dest.IsGeocentric)
{
if (z == null)
{
throw new ProjectionException(45);
}
GeocentricGeodetic g = new GeocentricGeodetic(dest.GeographicInfo.Datum.Spheroid);
g.GeodeticToGeocentric(xy, z, startIndex, numPoints);
double frmMeter = 1/dest.Unit.Meters;
if(frmMeter != 1)
{
for (int i = startIndex; i < numPoints; i++)
{
if (xy[i * 2] != double.PositiveInfinity)
{
xy[i * 2] *= frmMeter;
xy[i * 2+1] *= frmMeter;
}
}
}
}
else
{
ConvertToProjected(dest, xy, startIndex, numPoints);
}
}
private static void DatumTransform(ProjectionInfo source, ProjectionInfo dest, double[] xy, double[] z, int startIndex, int numPoints)
{
Spheroid wgs84 = new Spheroid(Proj4Ellipsoids.WGS_1984);
Datum sDatum = source.GeographicInfo.Datum;
Datum dDatum = dest.GeographicInfo.Datum;
/* -------------------------------------------------------------------- */
/* We cannot do any meaningful datum transformation if either */
/* the source or destination are of an unknown datum type */
/* (ie. only a +ellps declaration, no +datum). This is new */
/* behavior for PROJ 4.6.0. */
/* -------------------------------------------------------------------- */
if( sDatum.DatumType == DatumTypes.Unknown ||
dDatum.DatumType == DatumTypes.Unknown) return;
/* -------------------------------------------------------------------- */
/* Short cut if the datums are identical. */
/* -------------------------------------------------------------------- */
if (sDatum.Matches(dDatum)) return;
double srcA = sDatum.Spheroid.EquatorialRadius;
double srcEs = sDatum.Spheroid.EccentricitySquared();
double dstA = dDatum.Spheroid.EquatorialRadius;
double dstEs = dDatum.Spheroid.EccentricitySquared();
/* -------------------------------------------------------------------- */
/* Create a temporary Z value if one is not provided. */
/* -------------------------------------------------------------------- */
if (z == null)
{
z = new double[xy.Length / 2];
}
/* -------------------------------------------------------------------- */
/* If this datum requires grid shifts, then apply it to geodetic */
/* coordinates. */
/* -------------------------------------------------------------------- */
if( sDatum.DatumType == DatumTypes.GridShift)
{
// pj_apply_gridshift( pj_param(srcdefn->params,"snadgrids").s, 0,
// point_count, point_offset, x, y, z );
GridShift.Apply(source.GeographicInfo.Datum.NadGrids, false, xy, startIndex, numPoints);
srcA = wgs84.EquatorialRadius;
srcEs = wgs84.EccentricitySquared();
}
if (dDatum.DatumType == DatumTypes.GridShift)
{
dstA = wgs84.EquatorialRadius;
dstEs = wgs84.EccentricitySquared();
}
/* ==================================================================== */
/* Do we need to go through geocentric coordinates? */
/* ==================================================================== */
if( srcEs != dstEs || srcA != dstA
|| sDatum.DatumType == DatumTypes.Param3
|| sDatum.DatumType == DatumTypes.Param7
|| dDatum.DatumType == DatumTypes.Param3
|| dDatum.DatumType == DatumTypes.Param7)
{
/* -------------------------------------------------------------------- */
/* Convert to geocentric coordinates. */
/* -------------------------------------------------------------------- */
GeocentricGeodetic gc = new GeocentricGeodetic(sDatum.Spheroid);
gc.GeodeticToGeocentric(xy, z, startIndex, numPoints);
/* -------------------------------------------------------------------- */
/* Convert between datums. */
/* -------------------------------------------------------------------- */
if( sDatum.DatumType == DatumTypes.Param3 || sDatum.DatumType == DatumTypes.Param7)
{
// pj_geocentric_to_wgs84( srcdefn, point_count, point_offset,x,y,z);
}
if( dDatum.DatumType == DatumTypes.Param3 || dDatum.DatumType == DatumTypes.Param7)
{
// pj_geocentric_from_wgs84( dstdefn, point_count,point_offset,x,y,z);
}
/* -------------------------------------------------------------------- */
/* Convert back to geodetic coordinates. */
/* -------------------------------------------------------------------- */
gc = new GeocentricGeodetic(dDatum.Spheroid);
gc.GeodeticToGeocentric(xy, z, startIndex, numPoints);
}
/* -------------------------------------------------------------------- */
/* Apply grid shift to destination if required. */
/* -------------------------------------------------------------------- */
if(dDatum.DatumType == DatumTypes.GridShift)
{
// pj_apply_gridshift( pj_param(dstdefn->params,"snadgrids").s, 1,
// point_count, point_offset, x, y, z );
GridShift.Apply(dest.GeographicInfo.Datum.NadGrids, true, xy, startIndex, numPoints);
}
}
