///<summary>
/// Get the centroid of a Region.
///</summary>
///<param name="cur">An optional curve used to define the region.</param>
///<returns>A nullable Point3d containing the centroid of the Region.</returns>
public static _AcGe.Point3d? GetCentroid(this _AcDb.Region reg, _AcDb.Curve cur = null)
{
if (cur == null)
{
var idc = new _AcDb.DBObjectCollection();
reg.Explode(idc);
if (idc.Count == 0)
{
return(null);
}
cur = idc[0] as _AcDb.Curve;
}
if (cur == null)
{
return(null);
}
var cs = cur.GetPlane().GetCoordinateSystem();
var o = cs.Origin;
var x = cs.Xaxis;
var y = cs.Yaxis;
var a = reg.AreaProperties(ref o, ref x, ref y);
var pl = new _AcGe.Plane(o, x, y);
return(pl.EvaluatePoint(a.Centroid));
}
private List <_Ge.Point3d> handle(_Db.Entity ent)
{
List <_Ge.Point3d> points = new List <_Ge.Point3d>();
if (ent == null)
{
return(points);
}
if (ent is _Db.Curve && !(ent is _Db.Polyline || ent is _Db.Polyline2d || ent is _Db.Polyline3d))
{
try
{
_Db.Curve cur = ent as _Db.Curve;
int segs = 3; //(ent is Line ? 3 : 20);
double param = cur.EndParam - cur.StartParam;
for (int i = 0; i < segs; i++)
{
try
{
_Ge.Point3d pt = cur.GetPointAtParameter(cur.StartParam + (i * param / (segs - 1)));
points.Add(pt);
}
catch { }
}
}
catch { }
}
else
{
_Db.DBObjectCollection objectCollection = new _Db.DBObjectCollection();
try
{
ent.Explode(objectCollection);
if (objectCollection.Count > 0)
{
foreach (_Db.DBObject bid in objectCollection)
{
_Db.Entity ent2 = bid as _Db.Entity;
if (ent2 != null && ent2.Visible)
{
List <_Ge.Point3d> currentPoints = handle(ent2);
points.AddRange(currentPoints);
}
bid.Dispose();
}
}
}
catch { }
}
if (ent is _Db.Circle)
{
_Db.Circle circle = ent as _Db.Circle;
List <_Ge.Point3d> circlePoints = getCirclePoints(circle);
points.AddRange(circlePoints);
}
else if (ent is _Db.Arc)
{
_Db.Arc arc = ent as _Db.Arc;
List <_Ge.Point3d> arcPoints = getArcPoints(arc);
points.AddRange(arcPoints);
}
return(points);
}
static private Curve ToRhino(this _OdDb.Curve crv)
{
return(crv.GetGeCurve().ToRhino());
}