/// <summary>Calculates the angle between two absolute directions</summary>
/// <param name="firstPhi">First absolute direction in radians</param>
/// <param name="secondPhi">Second absolute direction in radians</param>
/// <param name="path">Path to take from first to second</param>
/// <returns>The angle between both directions using the desired path</returns>
/// <remarks>
/// See the remarks on the TangentialPath enumeration to determine the exact
/// behavior of this function. A positive path is always from the first angle
/// to the second, independent of whether this is clockwise or counter-clockwise.
/// </remarks>
public static double AngleBetween(double firstPhi, double secondPhi, TangentialPath path)
{
double difference = secondPhi - firstPhi;
double angle;
if (path == TangentialPath.Shortest)
{
// Just unroll the difference of both angles and we have the angle
angle = Shared <UncheckedScalarMath> .Instance.Wrap(difference, 0.0, Perigon);
// Calculate angle of shortest path if we got the one of the longest path
if (angle >= System.Math.PI)
{
angle -= Perigon;
}
}
else
{
// Unroll the difference depending on the sign of the resulting angle
if (difference < 0.0)
{
angle = math.Wrap(difference, -Perigon, 0.0);
if (path == TangentialPath.Negative)
{
angle += Perigon;
}
}
else
{
angle = math.Wrap(difference, 0.0, Perigon);
if (path == TangentialPath.Negative)
{
angle -= Perigon;
}
}
}
return(angle);
}
/// <summary>Calculates the angle between two absolute directions</summary>
/// <param name="firstPhi">First absolute direction in radians</param>
/// <param name="secondPhi">Second absolute direction in radians</param>
/// <param name="path">Path to take from first to second</param>
/// <returns>The angle between both directions using the desired path</returns>
/// <remarks>
/// See the remarks on the TangentialPath enumeration to determine the exact
/// behavior of this function. A positive path is always from the first angle
/// to the second, independent of whether this is clockwise or counter-clockwise.
/// </remarks>
public static double AngleBetween(double firstPhi, double secondPhi, TangentialPath path) {
double difference = secondPhi - firstPhi;
double angle;
if(path == TangentialPath.Shortest) {
// Just unroll the difference of both angles and we have the angle
angle = Shared<UncheckedScalarMath>.Instance.Wrap(difference, 0.0, Perigon);
// Calculate angle of shortest path if we got the one of the longest path
if(angle >= System.Math.PI)
angle -= Perigon;
} else {
// Unroll the difference depending on the sign of the resulting angle
if(difference < 0.0) {
angle = math.Wrap(difference, -Perigon, 0.0);
if(path == TangentialPath.Negative)
angle += Perigon;
} else {
angle = math.Wrap(difference, 0.0, Perigon);
if(path == TangentialPath.Negative)
angle -= Perigon;
}
}
return angle;
}
