/// <summary>
/// Divides a 3D block into two
/// </summary>
/// <param name="block">The block to divide</param>
/// <param name="p0">The plane point for division</param>
/// <param name="pn">The plane normal for division</param>
/// <param name="newFaceConstructor">Constructor for the new face. Defaults to new NGon()</param>
/// <param name="threshold">The floating point threshold for division, defaults to 0.001 or 1mm</param>
/// <returns></returns>
public static object[] Divide(IBlock block, Vector3 p0, Vector3 pn, Func <IEnumerable <Vector3>, IPoly> newFaceConstructor = null, float threshold = 0.001f)
{
if (newFaceConstructor == null)
{
newFaceConstructor = x => new NGon(x);
}
List <IPoly> insideFaces = new List <IPoly>();
List <IPoly> outsideFaces = new List <IPoly>();
List <Vector3> newPoints = new List <Vector3>();
foreach (IPoly face in block.GetFaces())
{
object[] o = Divide(face, p0, pn, threshold);
var inside = o[0];
var outside = o[1];
var newPoint = o[2];
if (inside != null)
{
insideFaces.Add(inside as IPoly);
}
if (outside != null)
{
outsideFaces.Add(outside as IPoly);
}
if (newPoint != null)
{
newPoints.Add((Vector3)newPoint);
}
}
//construct new face
if (newPoints.Count > 3)
{
Vector3 center = Vector3.zero;
foreach (var point in newPoints)
{
center += point;
}
center = center / (float)newPoints.Count;
newPoints = Math3d.CircleSort(center, pn, newPoints.ToArray()).ToList();
}
outsideFaces.Add(newFaceConstructor(newPoints));
newPoints.Reverse();
insideFaces.Add(newFaceConstructor(newPoints));
return(new object[] {
insideFaces.Count >= 4 ? block.Clone(insideFaces) : null,
insideFaces.Count >= 4 ? block.Clone(outsideFaces) : null
});
}