private double GetArea(List <Coordinate> tempPolygon)
{
double area = Math.Abs(CgAlgorithms.SignedArea(tempPolygon));
if (_previousParts == null || _previousParts.Count == 0)
{
_firstPartIsCounterClockwise = CgAlgorithms.IsCounterClockwise(tempPolygon);
}
else
{
if (CgAlgorithms.IsCounterClockwise(tempPolygon) != _firstPartIsCounterClockwise)
{
area = -area;
}
}
if (Map.Projection != null)
{
if (Map.Projection.IsLatLon)
{
// this code really assumes the location is near the equator
const double RadiusOfEarth = 111319.5;
area *= RadiusOfEarth * RadiusOfEarth;
}
else
{
area *= Map.Projection.Unit.Meters * Map.Projection.Unit.Meters;
}
}
return(area);
}
