private static GeoPolygon getPolygonBuffer(GeoPolygon geoPolygon, double angleDistance, int pointsPerCircle, bool allowParallels)
{
geoPolygon = (GeoPolygon)geoPolygon.Clone();
double minAngle = Math.Sin(Math.Abs(angleDistance)) * Math.Sin(Math.PI / pointsPerCircle);
geoPolygon.ReduceSegments(minAngle);
geoPolygon.Densify(minAngle);
GnomonicProjection projection;
IGeometry geometry;
projectGeography(geoPolygon, out projection, out geometry);
Polygon planePolygon = (Polygon)geometry;
Polygon boundaryBuffer = getBoundsBuffer(geoPolygon, projection, angleDistance, pointsPerCircle, allowParallels);
ICollection <IGeometry> result;
if (angleDistance > 0)
{
result = planePolygon.Union(boundaryBuffer);
}
else
{
result = planePolygon.Difference(boundaryBuffer);
}
GeographyCollection geographyCollection = GeometrySpreader.GetGeographies(result, projection);
foreach (IGeography g in geographyCollection)
{
if (g is GeoPolygon)
{
return((GeoPolygon)g);
}
}
return(new GeoPolygon());
}
private static GeoPolygon getPolygonBuffer(GeoPolygon geoPolygon, double angleDistance, int pointsPerCircle, bool allowParallels)
{
geoPolygon = (GeoPolygon)geoPolygon.Clone();
double minAngle = Math.Sin(Math.Abs(angleDistance)) * Math.Sin(Math.PI / pointsPerCircle);
geoPolygon.ReduceSegments(minAngle);
geoPolygon.Densify(minAngle);
GnomonicProjection projection;
IGeometry geometry;
projectGeography(geoPolygon, out projection, out geometry);
Polygon planePolygon = (Polygon)geometry;
Polygon boundaryBuffer = getBoundsBuffer(geoPolygon, projection, angleDistance, pointsPerCircle, allowParallels);
ICollection<IGeometry> result;
if (angleDistance > 0)
result = planePolygon.Union(boundaryBuffer);
else
result = planePolygon.Difference(boundaryBuffer);
GeographyCollection geographyCollection = GeometrySpreader.GetGeographies(result, projection);
foreach (IGeography g in geographyCollection)
if (g is GeoPolygon)
return (GeoPolygon)g;
return new GeoPolygon();
}