/// <summary>
/// Initializes a new instance of the <see cref="Cylinder" /> class.
/// </summary>
/// <param name="facesAll">The faces all.</param>
/// <param name="axis">The axis.</param>
public Cylinder(IEnumerable <PolygonalFace> facesAll, Vector3 axis)
: base(facesAll)
{
var faces = Faces.FacesWithDistinctNormals();
var n = faces.Count;
var centers = new List <Vector3>();
var signedDistances = new List <double>();
MiscFunctions.SkewedLineIntersection(faces[0].Center, faces[0].Normal,
faces[n - 1].Center, faces[n - 1].Normal, out var center, out _, out _,
out var t1, out var t2);
if (!center.IsNull() && !center.IsNegligible())
{
centers.Add(center);
signedDistances.Add(t1);
signedDistances.Add(t2);
}
for (var i = 1; i < n; i++)
{
MiscFunctions.SkewedLineIntersection(faces[i].Center, faces[i].Normal,
faces[i - 1].Center, faces[i - 1].Normal, out center, out _, out _,
out t1, out t2);
if (!center.IsNull() && !center.IsNegligible())
{
centers.Add(center);
signedDistances.Add(t1);
signedDistances.Add(t2);
}
}
center = new Vector3();
center = centers.Aggregate(center, (current, c) => current + c);
center = center.Divide(centers.Count);
/* move center to origin plane */
var distBackToOrigin = -1 * axis.Dot(center);
center = center - (axis * distBackToOrigin);
/* determine is positive or negative */
var numNeg = signedDistances.Count(d => d < 0);
var numPos = signedDistances.Count(d => d > 0);
var isPositive = numNeg > numPos;
var radii = new List <double>();
foreach (var face in faces)
{
radii.AddRange(face.Vertices.Select(v => MiscFunctions.DistancePointToLine(v.Coordinates, center, axis)));
}
var averageRadius = radii.Average();
Axis = axis;
Anchor = center;
IsPositive = isPositive;
Radius = averageRadius;
}