public double GetAngle(Turn that)
{
return GetAngleInRadians(that.BearingInRadians, 0.0);
}
public double GetAngle(Turn that)
{
return(GetAngleInRadians(that.BearingInRadians, 0.0));
}
/// <summary>
/// Checks whether a location falls in the sector lying between two points on a
/// clockwise circular arc. The only condition is that the location has an appropriate
/// bearing with respect to the bearings of the BC & EC (i.e. the location does not
/// necessarily lie ON the arc).
/// </summary>
/// <param name="pos">The position to check</param>
/// <param name="centre">The centre of the circular arc</param>
/// <param name="start">The first point of the arc (reckoned clockwise)</param>
/// <param name="end">The second point of the arc (reckoned clockwise)</param>
/// <param name="angtol">Angular tolerance (locations that are beyond the BC or EC
/// by up to this much will also be regarded as "in-sector").</param>
/// <returns>True if position falls in the sector defined by the arc</returns>
public static bool IsInSector(IPosition pos
, IPosition centre
, IPosition start
, IPosition end
, double angtol)
{
// Work out the clockwise angle, using the direction from
// the centre to the start of sector as the reference
// bearing.
// 18-OCT-99: I think the following only finds close matches
// at the start of the curve, since the angular tolerance
// is compared with respect to the reference bearing.
// CeTurn turn(centre,start);
// if ( turn.GetAngle(*this,angtol) <= turn.GetAngle(end,angtol) )
// return TRUE;
// else
// return FALSE;
/*
* Don't know what's wrong with the following ...
*
* // Define a reference bearing through THIS location.
* CeTurn turn(centre,*this);
*
* // Get the angle to the BC & check for an exact match.
* FLOAT8 sAngle = turn.GetAngle(start,angtol);
* if ( sAngle<TINY ) return TRUE;
*
* // Same for the EC.
* FLOAT8 eAngle = turn.GetAngle(end,angtol);
* if ( eAngle<TINY ) return TRUE;
*
* // This location is in sector if the angle to the EC
* // is less than the angle to the BC.
* return (eAngle<sAngle);
*/
// Check if definitely in sector.
Turn turn = new Turn(centre, start);
double aThis = turn.GetAngleInRadians(pos);
double aEnd = turn.GetAngleInRadians(end);
if (aThis <= aEnd)
{
return(true);
}
Debug.Assert(aThis >= 0.0 && aThis <= MathConstants.PIMUL2);
Debug.Assert(aEnd >= 0.0 && aEnd <= MathConstants.PIMUL2);
if (angtol > MathConstants.TINY)
{
// Check for match at the start of the curve.
if (aThis < angtol || Math.Abs(aThis - MathConstants.PIMUL2) < angtol)
{
return(true);
}
// And at the end of the curve.
if (Math.Abs(aThis - aEnd) < angtol)
{
return(true);
}
}
return(false);
}
/// <summary>
/// Checks whether a location falls in the sector lying between two points on a
/// clockwise circular arc. The only condition is that the location has an appropriate
/// bearing with respect to the bearings of the BC & EC (i.e. the location does not
/// necessarily lie ON the arc).
/// </summary>
/// <param name="pos">The position to check</param>
/// <param name="centre">The centre of the circular arc</param>
/// <param name="start">The first point of the arc (reckoned clockwise)</param>
/// <param name="end">The second point of the arc (reckoned clockwise)</param>
/// <param name="angtol">Angular tolerance (locations that are beyond the BC or EC
/// by up to this much will also be regarded as "in-sector").</param>
/// <returns>True if position falls in the sector defined by the arc</returns>
public static bool IsInSector( IPosition pos
, IPosition centre
, IPosition start
, IPosition end
, double angtol)
{
// Work out the clockwise angle, using the direction from
// the centre to the start of sector as the reference
// bearing.
// 18-OCT-99: I think the following only finds close matches
// at the start of the curve, since the angular tolerance
// is compared with respect to the reference bearing.
// CeTurn turn(centre,start);
// if ( turn.GetAngle(*this,angtol) <= turn.GetAngle(end,angtol) )
// return TRUE;
// else
// return FALSE;
/*
Don't know what's wrong with the following ...
// Define a reference bearing through THIS location.
CeTurn turn(centre,*this);
// Get the angle to the BC & check for an exact match.
FLOAT8 sAngle = turn.GetAngle(start,angtol);
if ( sAngle<TINY ) return TRUE;
// Same for the EC.
FLOAT8 eAngle = turn.GetAngle(end,angtol);
if ( eAngle<TINY ) return TRUE;
// This location is in sector if the angle to the EC
// is less than the angle to the BC.
return (eAngle<sAngle);
*/
// Check if definitely in sector.
Turn turn = new Turn(centre, start);
double aThis = turn.GetAngleInRadians(pos);
double aEnd = turn.GetAngleInRadians(end);
if (aThis <= aEnd)
return true;
Debug.Assert(aThis>=0.0 && aThis<=MathConstants.PIMUL2);
Debug.Assert(aEnd>=0.0 && aEnd<=MathConstants.PIMUL2);
if (angtol > MathConstants.TINY)
{
// Check for match at the start of the curve.
if (aThis<angtol || Math.Abs(aThis-MathConstants.PIMUL2)<angtol)
return true;
// And at the end of the curve.
if (Math.Abs(aThis-aEnd)<angtol)
return true;
}
return false;
}
