public Polygon Extend(double extentionSize)
{
if (IsValid())
{
List <Coordonnees> newCoordCollection = new List <Coordonnees>();
for (int i = 0; i < NbPoints; i++)
{
ZZCoordinate previousPoint = (ZZCoordinate)Coordonnees[ZZFunctions.nmod(i - 1, NbPoints)], anglePoint = (ZZCoordinate)Coordonnees[i], nextPoint = (ZZCoordinate)Coordonnees[(i + 1) % NbPoints];
double alpha = ZZMath.AngleFrom3Points(previousPoint, anglePoint, nextPoint), beta = (180 - alpha) / 2.0;
double slopeAngle = ZZMath.SlopeAngle(previousPoint, anglePoint) + beta;
double distanceToAdd = extentionSize / Math.Cos(ZZMath.ToRadians(beta));
double newX = anglePoint.X + distanceToAdd * Math.Cos(ZZMath.ToRadians(slopeAngle));
double newY = anglePoint.Y + distanceToAdd * Math.Sin(ZZMath.ToRadians(slopeAngle));
newCoordCollection.Add(new Coordonnees(newX, newY));
}
return(new Polygon(newCoordCollection, BackgroundColor, BorderColor, Oppacity));
}
return(this);
}
