/// <summary>
/// Compute the angle between two edges
/// </summary>
/// <param name="edgeA">The 1st edge</param>
/// <param name="edgeB">The 2nd edge</param>
/// <returns>The angle of the 2 edges</returns>
private double AngleBetweenEdges(Edge edgeA, Edge edgeB)
{
Autodesk.Revit.DB.XYZ vectorA = null;
Autodesk.Revit.DB.XYZ vectorB = null;
// find coincident vertices
Autodesk.Revit.DB.XYZ A_0 = edgeA.Evaluate(0);
Autodesk.Revit.DB.XYZ A_1 = edgeA.Evaluate(1);
Autodesk.Revit.DB.XYZ B_0 = edgeB.Evaluate(0);
Autodesk.Revit.DB.XYZ B_1 = edgeB.Evaluate(1);
if (A_0.IsAlmostEqualTo(B_0))
{
vectorA = edgeA.ComputeDerivatives(0).BasisX.Normalize();
vectorB = edgeA.ComputeDerivatives(0).BasisX.Normalize();
}
else if (A_0.IsAlmostEqualTo(B_1))
{
vectorA = edgeA.ComputeDerivatives(0).BasisX.Normalize();
vectorB = edgeB.ComputeDerivatives(1).BasisX.Normalize();
}
else if (A_1.IsAlmostEqualTo(B_0))
{
vectorA = edgeA.ComputeDerivatives(1).BasisX.Normalize();
vectorB = edgeB.ComputeDerivatives(0).BasisX.Normalize();
}
else if (A_1.IsAlmostEqualTo(B_1))
{
vectorA = edgeA.ComputeDerivatives(1).BasisX.Normalize();
vectorB = edgeB.ComputeDerivatives(1).BasisX.Normalize();
}
if (A_1.IsAlmostEqualTo(B_0) || A_0.IsAlmostEqualTo(B_1))
{
vectorA = vectorA.Negate();
}
if (null == vectorA || null == vectorB)
{
return(0d);
}
double angle = Math.Acos(vectorA.DotProduct(vectorB));
return(angle);
}