/// <summary>
/// Find the optimal split for a polygon
/// </summary>
/// <param name="poly"></param>
/// <returns></returns>
private (Vector3 point, Vector3 normal, List <BSPPoly <T> > left, List <BSPPoly <T> > right) FindOptimalSplit(BSPPoly <T>[] poly)
{
//init
Vector3 point = Vector3.zero, normal = Vector3.zero;
List <BSPPoly <T> > left = null, right = null;
//optimal diff
int diff = int.MaxValue;
//get the working polygon
IPoly working = poly[0].working;
for (int i = 0; i < working.Resolution; i++)
{
//get the current point and normal
Vector3 localPoint = working.GetPoint(i),
localNormal = working.GetSurfaceNormal(i);
//get output
(List <BSPPoly <T> > localInside, List <BSPPoly <T> > localOutput) = GetSplit(poly, localPoint, localNormal);
//calc the diff, and compare
int localDiff = Math.Abs(localInside.Count - localOutput.Count);
if (localDiff < diff)
{
left = localInside;
right = localOutput;
point = localPoint;
normal = localNormal;
diff = localDiff;
}
}
return(point, normal, left, right);
}
public BSPNode(BSPPoly <T> poly, BSPNode <T> inside, BSPNode <T> outside, Vector3 planePoint, Vector3 planeNormal)
{
this.poly = poly;
this.inside = inside;
this.outside = outside;
this.planePoint = planePoint;
this.planeNormal = planeNormal;
}
/// <summary>
/// Get the split for polys[0], for the specified point and normal
/// </summary>
/// <param name="polys"></param>
/// <param name="point"></param>
/// <param name="normal"></param>
/// <param name="startPoly"></param>
/// <returns></returns>
private (List <BSPPoly <T> > left, List <BSPPoly <T> > right) GetSplit(BSPPoly <T>[] polys, Vector3 point, Vector3 normal, int startPoly = 1)
{
List <BSPPoly <T> > inside = new List <BSPPoly <T> >(), outside = new List <BSPPoly <T> >();
for (int i = startPoly; i < polys.Length; i++)
{
BSPPoly <T> poly = polys[i];
IPoly working = poly.working;
object[] split = CSG.Geometry.CSGGeometry.Divide(working, point, normal);
if (split[0] != null)
{
inside.Add(new BSPPoly <T>(poly.original, (IPoly)split[0]));
}
if (split[1] != null)
{
outside.Add(new BSPPoly <T>(poly.original, (IPoly)split[1]));
}
}
return(inside, outside);
}