private Arc CreateArc(XYZ PointStart, XYZ PointEnd, double radius, bool largeSagitta)
{
XYZ midPointChord = 0.5 * (PointStart + PointEnd);
XYZ v = null;
if (!(bool)this.GetArcRotationAntiClockWise())
{
v = PointEnd - PointStart;
}
else
{
v = PointStart - PointEnd;
}
double d = 0.5 * v.GetLength(); // half chord length
// Small and large circle sagitta:
// http://www.mathopenref.com/sagitta.html
double s = largeSagitta
? radius + Math.Sqrt(radius * radius - d * d) // sagitta large
: radius - Math.Sqrt(radius * radius - d * d); // sagitta small
var PX = Transform.CreateRotation(XYZ.BasisZ, 0.5 * Math.PI);
var PX2 = v.Normalize();
var PX3 = v.Normalize().Multiply(s);
XYZ midPointArc = midPointChord + Transform.CreateRotation(XYZ.BasisZ, 0.5 * Math.PI).OfVector(v.Normalize().Multiply(s));
return(Arc.Create(PointEnd, PointStart, midPointArc));
}
public static Arc CreateArcFromCircCurve(XYZ PointStart, XYZ PointEnd, double radius, bool largeSagitta)
{
PointStart = new XYZ(PointStart.X, PointStart.Z, 0);
PointEnd = new XYZ(PointEnd.X, PointEnd.Z, 0);
XYZ midPointChord = 0.5 * (PointStart + PointEnd);
XYZ v = null;
//if (!(bool)this.GetArcRotationAntiClockWise())
//{
// v = PointEnd - PointStart;
//}
//else
//{
v = PointStart - PointEnd;
//} //}
double d = 0.5 * v.GetLength(); // half chord length
// Small and large circle sagitta:
// http://www.mathopenref.com/sagitta.html
double s = largeSagitta
? radius + Math.Sqrt(radius * radius - d * d) // sagitta large
: radius - Math.Sqrt(radius * radius - d * d); // sagitta small
var PX = Transform.CreateRotation(XYZ.BasisZ, 0.5 * Math.PI);
var PX2 = v.Normalize();
var PX3 = v.Normalize().Multiply(s);
XYZ midPointArc = midPointChord + Transform.CreateRotation(XYZ.BasisZ, 0.5 * Math.PI).OfVector(v.Normalize().Multiply(s));
var PointARcEnd = new XYZ(PointEnd.X, PointEnd.Z, PointEnd.Y);
var PointArcStart = new XYZ(PointStart.X, PointStart.Z, PointStart.Y);
var PointArcMid = new XYZ(midPointArc.X, midPointArc.Z, midPointArc.Y);
return(Arc.Create(PointARcEnd, PointArcStart, PointArcMid));
}