/// <summary>
/// This function returns the difference of the input arguments as (Arg1 - Arg2).
/// The function returns as a vector the vector difference of the two input vectors.
/// The input arguments shall both be of the same dimensionality but may be either directions or vectors.
/// If both input arguments are vectors they must be expressed in the same units, if both are directions a unitless result is produced.
/// A zero difference vector produces a vector of zero magnitude.
/// </summary>
/// <param name="arg1"></param>
/// <param name="arg2"></param>
/// <returns></returns>
public static IfcVector IfcVectorDifference(IfcDirection arg1, IfcVector arg2)
{
if (arg1 == null || arg2 == null || arg1.Dim != arg2.Dim)
{
return(null);
}
return(IfcVectorDifference(1, arg1, arg2.Magnitude, arg2.Orientation.Item));
}
/// <summary>
/// Constructor accepting underlying data
/// </summary>
/// <param name="point"></param>
/// <param name="direction"></param>
public IfcLine(IfcCartesianPoint point, IfcVector direction)
{
if (point == null)
{
throw new ArgumentNullException("point");
}
if (direction == null)
{
throw new ArgumentNullException("direction");
}
this.Pnt = (IfcLinePnt)point;
this.Dir = (IfcLineDir)direction;
}
/// <summary>
/// This function returns a vector whose components are normalized to have a sum of squares of 1.0.
/// If the input argument is not defined or of zero length then null is returned.
/// </summary>
/// <param name="arg"></param>
/// <returns></returns>
public static IfcVector IfcNormalise(IfcVector arg)
{
if (arg == null)
{
throw new ArgumentNullException("arg");
}
IfcDimensionCount1 Ndim;
IfcDirection V = new IfcDirection(1, 0);
IfcVector Vec = new IfcVector(new IfcDirection(1, 0), 1);
doublewrapper Mag;
Ndim = arg.Dim;
V.DirectionRatios = arg.Orientation.Item.DirectionRatios;
Vec.Magnitude = arg.Magnitude;
Vec.Orientation = (IfcVectorOrientation)V;
if (arg.Magnitude == 0)
{
return(null);
}
Vec.Magnitude = 1;
Mag = 0;
for (int i = 0; i < Ndim; i++)
{
Mag += V.DirectionRatios[i] * V.DirectionRatios[i];
}
if (Mag <= 0)
{
return(null);
}
Mag = Math.Sqrt((double)Mag);
for (int i = 0; i < Ndim; i++)
{
V.DirectionRatios[i] /= Mag;
}
Vec.Orientation = (IfcVectorOrientation)V;
return(Vec);
}
/// <summary>
/// This function returns the vector that is the scalar multiple of the input vector.
/// It accepts as input a scalar and a 'vector' which may be either a Direction or a Vector.
/// The output is a Vector of the same units as the input vector or unitless if a direction is input.
/// If either input argument is undefined then the returned vector is also undefined.
/// </summary>
/// <param name="scalar"></param>
/// <param name="vec"></param>
/// <returns></returns>
public static IfcVector IfcScalarTimesVector(double scalar, IfcVector vec)
{
if (vec == null)
{
return(null);
}
IfcDirection V;
double Mag;
V = vec.Orientation.Item;
Mag = scalar * vec.Magnitude;
if (Mag < 0)
{
for (int i = 0; i < V.DirectionRatios.Items.Length; i++)
{
V.DirectionRatios[i] = -V.DirectionRatios[i];
}
Mag = -Mag;
}
return(new IfcVector(IfcNormalise(V), Mag));
}
