public Normal3 Sample(Random random)
{
ISphere sphere = new UnitSphere(Position3.Origin);
Normal3 direction = ((Direction3)sphere.SurfacePosition(random)).Normalized();
return(IDirection3.InSameClosedHemisphere(Orientation, direction) ? direction : -direction);
}
private double[] applyInverted(double[] p)
{
double[] result = new double[p.Length];
int delta = 2;
if (p.Length % 3 == 0)
{
delta = 3;
}
for (int i = 0; i < p.Length / 2; i += delta)
{
if (delta == 3)
{
result[i + 2] = p[i + 2];
}
Vector3 vector = _center + _xAxis * p[i] + _yAxis * p[i + 1];
result[i + 1] = Radians.ToDegrees(UnitSphere.Latitude(vector));
result[i] = Radians.ToDegrees(UnitSphere.Longitude(vector));
}
return(result);
}
/// <summary>
/// Initializes a new instance of the MapAround.CoordinateSystems.Transformations.Gnomonic.
/// </summary>
/// <param name="centerLongitude">Longitude of projection center in degrees</param>
/// <param name="centerLatitude">Latitude of projection center in degrees</param>
public Gnomonic(double centerLongitude, double centerLatitude)
: this(false)
{
_center =
UnitSphere.LatLonToGeocentric(
Degrees.ToRadians(centerLatitude),
Degrees.ToRadians(centerLongitude));
double[] center = { _center.X, _center.Y, _center.Z };
double[] vector = new double[3];
int k = getMinEntryIndex(center);
int j = (k + 2) % 3;
int i = (j + 2) % 3;
vector[i] = -center[j];
vector[j] = center[i];
vector[k] = 0;
_xAxis = (new Vector3(vector[0], vector[1], vector[2])).Unitize();
_yAxis = _center.CrossProduct(_xAxis);
}
private double[] apply(double[] p)
{
double[] result = new double[p.Length];
int delta = 2;
if (p.Length % 3 == 0)
{
delta = 3;
}
for (int i = 0; i < p.Length / 2; i += delta)
{
if (delta == 3)
{
result[i + 2] = p[i + 2];
}
Vector3 vector =
UnitSphere.LatLonToGeocentric(
Degrees.ToRadians(p[i + 1]),
Degrees.ToRadians(p[i]));
double r = vector * _center;
if (r < 1e-8)
{
throw new ApplicationException();
}
vector = vector / r;
result[i] = vector * _xAxis;
result[i + 1] = vector * _yAxis;
}
return(result);
}
public Normal3 Sample(Random random)
{
ISphere sphere = new UnitSphere(Position3.Origin);
return(new Normal3(sphere.SurfacePosition(random).Vector));
}