/// <summary>
/// Returns the centroid.
/// </summary>
public C2DPoint GetCentroid()
{
// Find the centroid and area of the straight line polygon.
C2DPoint Centroid = new C2DPoint(0, 0);
// C2DPoint pti = new C2DPoint();
// C2DPoint ptii;
double dArea = 0;
for (int i = 0; i < Lines.Count; i++)
{
C2DPoint pti = Lines[i].GetPointFrom();
C2DPoint ptii = Lines[i].GetPointTo();
Centroid.x += (pti.x + ptii.x) * (pti.x * ptii.y - ptii.x * pti.y);
Centroid.y += (pti.y + ptii.y) * (pti.x * ptii.y - ptii.x * pti.y);
dArea += pti.x * ptii.y - ptii.x * pti.y;
}
dArea = dArea / 2.0;
Centroid.x = Centroid.x / (6.0 * dArea);
Centroid.y = Centroid.y / (6.0 * dArea);
List <double> dSegAreas = new List <double>();
double dTotalArea = dArea;
List <C2DPoint> SegCentroids = new List <C2DPoint>();
for (int i = 0; i < Lines.Count; i++)
{
if (Lines[i] is C2DArc)
{
C2DSegment Seg = new C2DSegment(Lines[i] as C2DArc);
double dSegArea = Seg.GetAreaSigned();
dTotalArea += dSegArea;
dSegAreas.Add(dSegArea);
SegCentroids.Add(Seg.GetCentroid());
}
}
Centroid.Multiply(dArea);
for (int i = 0; i < dSegAreas.Count; i++)
{
Centroid.x += SegCentroids[i].x * dSegAreas[i];
Centroid.y += SegCentroids[i].y * dSegAreas[i];
}
Centroid.Multiply(1 / dTotalArea);
return(Centroid);
}
/// <summary>
/// Returns the centroid.
/// </summary>
public C2DPoint GetCentroid()
{
// Find the centroid and area of the straight line polygon.
C2DPoint Centroid = new C2DPoint(0, 0);
// C2DPoint pti = new C2DPoint();
// C2DPoint ptii;
double dArea = 0;
for (int i = 0; i < Lines.Count; i++)
{
C2DPoint pti = Lines[i].GetPointFrom();
C2DPoint ptii = Lines[i].GetPointTo();
Centroid.x += (pti.x + ptii.x) * (pti.x * ptii.y - ptii.x * pti.y);
Centroid.y += (pti.y + ptii.y) * (pti.x * ptii.y - ptii.x * pti.y);
dArea += pti.x * ptii.y - ptii.x * pti.y;
}
dArea = dArea / 2.0;
Centroid.x = Centroid.x / (6.0 * dArea);
Centroid.y = Centroid.y / (6.0 * dArea);
List<double> dSegAreas = new List<double>();
double dTotalArea = dArea;
List<C2DPoint> SegCentroids = new List<C2DPoint>();
for (int i = 0; i < Lines.Count; i++)
{
if (Lines[i] is C2DArc)
{
C2DSegment Seg = new C2DSegment( Lines[i] as C2DArc );
double dSegArea = Seg.GetAreaSigned();
dTotalArea += dSegArea;
dSegAreas.Add( dSegArea );
SegCentroids.Add( Seg.GetCentroid() );
}
}
Centroid.Multiply( dArea);
for (int i = 0; i < dSegAreas.Count; i++)
{
Centroid.x += SegCentroids[i].x * dSegAreas[i];
Centroid.y += SegCentroids[i].y * dSegAreas[i];
}
Centroid.Multiply( 1/ dTotalArea);
return Centroid;
}
