// Returns the maximum error in the result of UpdateMinDistance (and
// associated functions such as UpdateMinInteriorDistance, IsDistanceLess,
// etc), assuming that all input points are normalized to within the bounds
// guaranteed by S2Point.Normalize(). The error can be added or subtracted
// from an S1ChordAngle "x" using x.PlusError(error).
//
// Note that accuracy goes down as the distance approaches 0 degrees or 180
// degrees (for different reasons). Near 0 degrees the error is acceptable
// for all practical purposes (about 1.2e-15 radians ~= 8 nanometers). For
// exactly antipodal points the maximum error is quite high (0.5 meters), but
// this error drops rapidly as the points move away from antipodality
// (approximately 1 millimeter for points that are 50 meters from antipodal,
// and 1 micrometer for points that are 50km from antipodal).
public static double GetUpdateMinDistanceMaxError(S1ChordAngle dist)
{
// There are two cases for the maximum error in UpdateMinDistance(),
// depending on whether the closest point is interior to the edge.
return(Math.Max(GetUpdateMinInteriorDistanceMaxError(dist),
dist.GetS2PointConstructorMaxError()));
}