public static PointF RotatePoint(PointF pt, PointF center, double ang)
{
double prevAngle = Math.Atan2(pt.Y - center.Y, pt.X - center.X);
double newAngle = prevAngle + ang;
double distance = PointOps.Distance(pt, center);
PointF rotatedOffset = new PointF((float)(Math.Cos(newAngle) * distance), (float)(Math.Sin(newAngle) * distance));
return(PointOps.Add(center, rotatedOffset));
}
public static LineF RotateLine(LineF ln, double ang)
{
PointF center = PointOps.Mult(PointOps.Add(ln.p1, ln.p2), 0.5f);
return(RotateLineAroundPoint(ln, center, ang));
}
