public static void ReprojectPoints(double[] xy, double[] z, ProjectionInfo source, double srcZtoMeter, ProjectionInfo dest, double dstZtoMeter, IDatumTransform idt, int startIndex, int numPoints)
{
if (xy == null || source?.Equals(dest) == true || numPoints <= 0)
{
return;
}
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, z, srcZtoMeter, 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 (idt == null)
{
if (!source.GeographicInfo.Datum.Matches(dest.GeographicInfo.Datum))
{
DatumTransform(source, dest, xy, z, startIndex, numPoints);
}
}
else
{
idt.Transform(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] -= 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, z, dstZtoMeter, startIndex, numPoints);
}
}
